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925ca369 KG |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | ||
d189f627 | 3 | #include <linux/anon_inodes.h> |
3c0d9c63 | 4 | #include <linux/atomic.h> |
925ca369 | 5 | #include <linux/bitmap.h> |
3c0d9c63 | 6 | #include <linux/build_bug.h> |
d189f627 | 7 | #include <linux/cdev.h> |
9344e34e | 8 | #include <linux/cleanup.h> |
d189f627 | 9 | #include <linux/compat.h> |
65cff704 | 10 | #include <linux/compiler.h> |
925ca369 KG |
11 | #include <linux/device.h> |
12 | #include <linux/err.h> | |
d189f627 | 13 | #include <linux/file.h> |
925ca369 KG |
14 | #include <linux/gpio.h> |
15 | #include <linux/gpio/driver.h> | |
52ee7c02 | 16 | #include <linux/hte.h> |
d189f627 KG |
17 | #include <linux/interrupt.h> |
18 | #include <linux/irqreturn.h> | |
19 | #include <linux/kernel.h> | |
925ca369 | 20 | #include <linux/kfifo.h> |
d189f627 | 21 | #include <linux/module.h> |
a54756cb | 22 | #include <linux/mutex.h> |
ede7511e | 23 | #include <linux/overflow.h> |
d189f627 | 24 | #include <linux/pinctrl/consumer.h> |
925ca369 | 25 | #include <linux/poll.h> |
9344e34e | 26 | #include <linux/rbtree.h> |
52ee7c02 | 27 | #include <linux/seq_file.h> |
d189f627 | 28 | #include <linux/spinlock.h> |
925ca369 | 29 | #include <linux/timekeeping.h> |
d189f627 | 30 | #include <linux/uaccess.h> |
65cff704 | 31 | #include <linux/workqueue.h> |
52ee7c02 | 32 | |
925ca369 KG |
33 | #include <uapi/linux/gpio.h> |
34 | ||
35 | #include "gpiolib.h" | |
36 | #include "gpiolib-cdev.h" | |
37 | ||
3c0d9c63 KG |
38 | /* |
39 | * Array sizes must ensure 64-bit alignment and not create holes in the | |
40 | * struct packing. | |
41 | */ | |
42 | static_assert(IS_ALIGNED(GPIO_V2_LINES_MAX, 2)); | |
43 | static_assert(IS_ALIGNED(GPIO_MAX_NAME_SIZE, 8)); | |
44 | ||
45 | /* | |
46 | * Check that uAPI structs are 64-bit aligned for 32/64-bit compatibility | |
47 | */ | |
48 | static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_attribute), 8)); | |
49 | static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_config_attribute), 8)); | |
50 | static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_config), 8)); | |
51 | static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_request), 8)); | |
52 | static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_info), 8)); | |
53 | static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_info_changed), 8)); | |
54 | static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_event), 8)); | |
55 | static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_values), 8)); | |
56 | ||
925ca369 KG |
57 | /* Character device interface to GPIO. |
58 | * | |
59 | * The GPIO character device, /dev/gpiochipN, provides userspace an | |
60 | * interface to gpiolib GPIOs via ioctl()s. | |
61 | */ | |
62 | ||
63 | /* | |
64 | * GPIO line handle management | |
65 | */ | |
66 | ||
3c0d9c63 | 67 | #ifdef CONFIG_GPIO_CDEV_V1 |
925ca369 KG |
68 | /** |
69 | * struct linehandle_state - contains the state of a userspace handle | |
70 | * @gdev: the GPIO device the handle pertains to | |
71 | * @label: consumer label used to tag descriptors | |
72 | * @descs: the GPIO descriptors held by this handle | |
52b7b596 | 73 | * @num_descs: the number of descriptors held in the descs array |
925ca369 KG |
74 | */ |
75 | struct linehandle_state { | |
76 | struct gpio_device *gdev; | |
77 | const char *label; | |
78 | struct gpio_desc *descs[GPIOHANDLES_MAX]; | |
52b7b596 | 79 | u32 num_descs; |
925ca369 KG |
80 | }; |
81 | ||
82 | #define GPIOHANDLE_REQUEST_VALID_FLAGS \ | |
83 | (GPIOHANDLE_REQUEST_INPUT | \ | |
84 | GPIOHANDLE_REQUEST_OUTPUT | \ | |
85 | GPIOHANDLE_REQUEST_ACTIVE_LOW | \ | |
86 | GPIOHANDLE_REQUEST_BIAS_PULL_UP | \ | |
87 | GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | \ | |
88 | GPIOHANDLE_REQUEST_BIAS_DISABLE | \ | |
89 | GPIOHANDLE_REQUEST_OPEN_DRAIN | \ | |
90 | GPIOHANDLE_REQUEST_OPEN_SOURCE) | |
91 | ||
92 | static int linehandle_validate_flags(u32 flags) | |
93 | { | |
94 | /* Return an error if an unknown flag is set */ | |
95 | if (flags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) | |
96 | return -EINVAL; | |
97 | ||
98 | /* | |
99 | * Do not allow both INPUT & OUTPUT flags to be set as they are | |
100 | * contradictory. | |
101 | */ | |
102 | if ((flags & GPIOHANDLE_REQUEST_INPUT) && | |
103 | (flags & GPIOHANDLE_REQUEST_OUTPUT)) | |
104 | return -EINVAL; | |
105 | ||
106 | /* | |
107 | * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If | |
108 | * the hardware actually supports enabling both at the same time the | |
109 | * electrical result would be disastrous. | |
110 | */ | |
111 | if ((flags & GPIOHANDLE_REQUEST_OPEN_DRAIN) && | |
112 | (flags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) | |
113 | return -EINVAL; | |
114 | ||
115 | /* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */ | |
116 | if (!(flags & GPIOHANDLE_REQUEST_OUTPUT) && | |
117 | ((flags & GPIOHANDLE_REQUEST_OPEN_DRAIN) || | |
118 | (flags & GPIOHANDLE_REQUEST_OPEN_SOURCE))) | |
119 | return -EINVAL; | |
120 | ||
121 | /* Bias flags only allowed for input or output mode. */ | |
122 | if (!((flags & GPIOHANDLE_REQUEST_INPUT) || | |
123 | (flags & GPIOHANDLE_REQUEST_OUTPUT)) && | |
124 | ((flags & GPIOHANDLE_REQUEST_BIAS_DISABLE) || | |
125 | (flags & GPIOHANDLE_REQUEST_BIAS_PULL_UP) || | |
126 | (flags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN))) | |
127 | return -EINVAL; | |
128 | ||
129 | /* Only one bias flag can be set. */ | |
130 | if (((flags & GPIOHANDLE_REQUEST_BIAS_DISABLE) && | |
131 | (flags & (GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | | |
a18512e3 | 132 | GPIOHANDLE_REQUEST_BIAS_PULL_UP))) || |
925ca369 KG |
133 | ((flags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) && |
134 | (flags & GPIOHANDLE_REQUEST_BIAS_PULL_UP))) | |
135 | return -EINVAL; | |
136 | ||
137 | return 0; | |
138 | } | |
139 | ||
c274b58a KG |
140 | static void linehandle_flags_to_desc_flags(u32 lflags, unsigned long *flagsp) |
141 | { | |
142 | assign_bit(FLAG_ACTIVE_LOW, flagsp, | |
143 | lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW); | |
144 | assign_bit(FLAG_OPEN_DRAIN, flagsp, | |
145 | lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN); | |
146 | assign_bit(FLAG_OPEN_SOURCE, flagsp, | |
147 | lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE); | |
148 | assign_bit(FLAG_PULL_UP, flagsp, | |
149 | lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP); | |
150 | assign_bit(FLAG_PULL_DOWN, flagsp, | |
151 | lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN); | |
152 | assign_bit(FLAG_BIAS_DISABLE, flagsp, | |
153 | lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE); | |
154 | } | |
155 | ||
925ca369 KG |
156 | static long linehandle_set_config(struct linehandle_state *lh, |
157 | void __user *ip) | |
158 | { | |
159 | struct gpiohandle_config gcnf; | |
160 | struct gpio_desc *desc; | |
161 | int i, ret; | |
162 | u32 lflags; | |
925ca369 KG |
163 | |
164 | if (copy_from_user(&gcnf, ip, sizeof(gcnf))) | |
165 | return -EFAULT; | |
166 | ||
167 | lflags = gcnf.flags; | |
168 | ret = linehandle_validate_flags(lflags); | |
169 | if (ret) | |
170 | return ret; | |
171 | ||
52b7b596 | 172 | for (i = 0; i < lh->num_descs; i++) { |
925ca369 | 173 | desc = lh->descs[i]; |
c274b58a | 174 | linehandle_flags_to_desc_flags(gcnf.flags, &desc->flags); |
925ca369 KG |
175 | |
176 | /* | |
177 | * Lines have to be requested explicitly for input | |
178 | * or output, else the line will be treated "as is". | |
179 | */ | |
180 | if (lflags & GPIOHANDLE_REQUEST_OUTPUT) { | |
181 | int val = !!gcnf.default_values[i]; | |
182 | ||
183 | ret = gpiod_direction_output(desc, val); | |
184 | if (ret) | |
185 | return ret; | |
186 | } else if (lflags & GPIOHANDLE_REQUEST_INPUT) { | |
187 | ret = gpiod_direction_input(desc); | |
188 | if (ret) | |
189 | return ret; | |
190 | } | |
191 | ||
9ce4ed5b | 192 | gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG); |
925ca369 KG |
193 | } |
194 | return 0; | |
195 | } | |
196 | ||
20bddcb4 KG |
197 | static long linehandle_ioctl(struct file *file, unsigned int cmd, |
198 | unsigned long arg) | |
925ca369 | 199 | { |
49bc5279 | 200 | struct linehandle_state *lh = file->private_data; |
925ca369 KG |
201 | void __user *ip = (void __user *)arg; |
202 | struct gpiohandle_data ghd; | |
203 | DECLARE_BITMAP(vals, GPIOHANDLES_MAX); | |
1cef8b50 AS |
204 | unsigned int i; |
205 | int ret; | |
925ca369 | 206 | |
d83cee3d | 207 | guard(srcu)(&lh->gdev->srcu); |
20bddcb4 | 208 | |
8574b5b4 | 209 | if (!rcu_access_pointer(lh->gdev->chip)) |
533aae7c BG |
210 | return -ENODEV; |
211 | ||
1cef8b50 AS |
212 | switch (cmd) { |
213 | case GPIOHANDLE_GET_LINE_VALUES_IOCTL: | |
214 | /* NOTE: It's okay to read values of output lines */ | |
215 | ret = gpiod_get_array_value_complex(false, true, | |
216 | lh->num_descs, lh->descs, | |
217 | NULL, vals); | |
925ca369 KG |
218 | if (ret) |
219 | return ret; | |
220 | ||
221 | memset(&ghd, 0, sizeof(ghd)); | |
52b7b596 | 222 | for (i = 0; i < lh->num_descs; i++) |
925ca369 KG |
223 | ghd.values[i] = test_bit(i, vals); |
224 | ||
225 | if (copy_to_user(ip, &ghd, sizeof(ghd))) | |
226 | return -EFAULT; | |
227 | ||
228 | return 0; | |
1cef8b50 | 229 | case GPIOHANDLE_SET_LINE_VALUES_IOCTL: |
925ca369 KG |
230 | /* |
231 | * All line descriptors were created at once with the same | |
232 | * flags so just check if the first one is really output. | |
233 | */ | |
234 | if (!test_bit(FLAG_IS_OUT, &lh->descs[0]->flags)) | |
235 | return -EPERM; | |
236 | ||
237 | if (copy_from_user(&ghd, ip, sizeof(ghd))) | |
238 | return -EFAULT; | |
239 | ||
240 | /* Clamp all values to [0,1] */ | |
52b7b596 | 241 | for (i = 0; i < lh->num_descs; i++) |
925ca369 KG |
242 | __assign_bit(i, vals, ghd.values[i]); |
243 | ||
244 | /* Reuse the array setting function */ | |
245 | return gpiod_set_array_value_complex(false, | |
a18512e3 | 246 | true, |
52b7b596 | 247 | lh->num_descs, |
a18512e3 KG |
248 | lh->descs, |
249 | NULL, | |
250 | vals); | |
1cef8b50 | 251 | case GPIOHANDLE_SET_CONFIG_IOCTL: |
925ca369 | 252 | return linehandle_set_config(lh, ip); |
1cef8b50 AS |
253 | default: |
254 | return -EINVAL; | |
925ca369 | 255 | } |
925ca369 KG |
256 | } |
257 | ||
258 | #ifdef CONFIG_COMPAT | |
49bc5279 | 259 | static long linehandle_ioctl_compat(struct file *file, unsigned int cmd, |
a18512e3 | 260 | unsigned long arg) |
925ca369 | 261 | { |
49bc5279 | 262 | return linehandle_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); |
925ca369 KG |
263 | } |
264 | #endif | |
265 | ||
883f9198 | 266 | static void linehandle_free(struct linehandle_state *lh) |
925ca369 | 267 | { |
925ca369 KG |
268 | int i; |
269 | ||
52b7b596 | 270 | for (i = 0; i < lh->num_descs; i++) |
883f9198 KG |
271 | if (lh->descs[i]) |
272 | gpiod_free(lh->descs[i]); | |
925ca369 | 273 | kfree(lh->label); |
dc0989e3 | 274 | gpio_device_put(lh->gdev); |
925ca369 | 275 | kfree(lh); |
883f9198 KG |
276 | } |
277 | ||
278 | static int linehandle_release(struct inode *inode, struct file *file) | |
279 | { | |
280 | linehandle_free(file->private_data); | |
925ca369 KG |
281 | return 0; |
282 | } | |
283 | ||
284 | static const struct file_operations linehandle_fileops = { | |
285 | .release = linehandle_release, | |
286 | .owner = THIS_MODULE, | |
287 | .llseek = noop_llseek, | |
288 | .unlocked_ioctl = linehandle_ioctl, | |
289 | #ifdef CONFIG_COMPAT | |
290 | .compat_ioctl = linehandle_ioctl_compat, | |
291 | #endif | |
292 | }; | |
293 | ||
294 | static int linehandle_create(struct gpio_device *gdev, void __user *ip) | |
295 | { | |
296 | struct gpiohandle_request handlereq; | |
297 | struct linehandle_state *lh; | |
298 | struct file *file; | |
883f9198 | 299 | int fd, i, ret; |
925ca369 KG |
300 | u32 lflags; |
301 | ||
302 | if (copy_from_user(&handlereq, ip, sizeof(handlereq))) | |
303 | return -EFAULT; | |
304 | if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX)) | |
305 | return -EINVAL; | |
306 | ||
307 | lflags = handlereq.flags; | |
308 | ||
309 | ret = linehandle_validate_flags(lflags); | |
310 | if (ret) | |
311 | return ret; | |
312 | ||
313 | lh = kzalloc(sizeof(*lh), GFP_KERNEL); | |
314 | if (!lh) | |
315 | return -ENOMEM; | |
dc0989e3 | 316 | lh->gdev = gpio_device_get(gdev); |
925ca369 | 317 | |
f188ac12 KG |
318 | if (handlereq.consumer_label[0] != '\0') { |
319 | /* label is only initialized if consumer_label is set */ | |
320 | lh->label = kstrndup(handlereq.consumer_label, | |
321 | sizeof(handlereq.consumer_label) - 1, | |
322 | GFP_KERNEL); | |
925ca369 KG |
323 | if (!lh->label) { |
324 | ret = -ENOMEM; | |
325 | goto out_free_lh; | |
326 | } | |
327 | } | |
328 | ||
883f9198 KG |
329 | lh->num_descs = handlereq.lines; |
330 | ||
925ca369 KG |
331 | /* Request each GPIO */ |
332 | for (i = 0; i < handlereq.lines; i++) { | |
333 | u32 offset = handlereq.lineoffsets[i]; | |
f4e14d45 | 334 | struct gpio_desc *desc = gpio_device_get_desc(gdev, offset); |
925ca369 KG |
335 | |
336 | if (IS_ERR(desc)) { | |
337 | ret = PTR_ERR(desc); | |
883f9198 | 338 | goto out_free_lh; |
925ca369 KG |
339 | } |
340 | ||
95a4eed7 | 341 | ret = gpiod_request_user(desc, lh->label); |
925ca369 | 342 | if (ret) |
883f9198 | 343 | goto out_free_lh; |
925ca369 | 344 | lh->descs[i] = desc; |
c274b58a | 345 | linehandle_flags_to_desc_flags(handlereq.flags, &desc->flags); |
925ca369 KG |
346 | |
347 | ret = gpiod_set_transitory(desc, false); | |
348 | if (ret < 0) | |
883f9198 | 349 | goto out_free_lh; |
925ca369 KG |
350 | |
351 | /* | |
352 | * Lines have to be requested explicitly for input | |
353 | * or output, else the line will be treated "as is". | |
354 | */ | |
355 | if (lflags & GPIOHANDLE_REQUEST_OUTPUT) { | |
356 | int val = !!handlereq.default_values[i]; | |
357 | ||
358 | ret = gpiod_direction_output(desc, val); | |
359 | if (ret) | |
883f9198 | 360 | goto out_free_lh; |
925ca369 KG |
361 | } else if (lflags & GPIOHANDLE_REQUEST_INPUT) { |
362 | ret = gpiod_direction_input(desc); | |
363 | if (ret) | |
883f9198 | 364 | goto out_free_lh; |
925ca369 KG |
365 | } |
366 | ||
9ce4ed5b | 367 | gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_REQUESTED); |
925ca369 KG |
368 | |
369 | dev_dbg(&gdev->dev, "registered chardev handle for line %d\n", | |
370 | offset); | |
371 | } | |
925ca369 KG |
372 | |
373 | fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC); | |
374 | if (fd < 0) { | |
375 | ret = fd; | |
883f9198 | 376 | goto out_free_lh; |
925ca369 KG |
377 | } |
378 | ||
379 | file = anon_inode_getfile("gpio-linehandle", | |
380 | &linehandle_fileops, | |
381 | lh, | |
382 | O_RDONLY | O_CLOEXEC); | |
383 | if (IS_ERR(file)) { | |
384 | ret = PTR_ERR(file); | |
385 | goto out_put_unused_fd; | |
386 | } | |
387 | ||
388 | handlereq.fd = fd; | |
389 | if (copy_to_user(ip, &handlereq, sizeof(handlereq))) { | |
390 | /* | |
391 | * fput() will trigger the release() callback, so do not go onto | |
392 | * the regular error cleanup path here. | |
393 | */ | |
394 | fput(file); | |
395 | put_unused_fd(fd); | |
396 | return -EFAULT; | |
397 | } | |
398 | ||
399 | fd_install(fd, file); | |
400 | ||
401 | dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n", | |
52b7b596 | 402 | lh->num_descs); |
925ca369 KG |
403 | |
404 | return 0; | |
405 | ||
406 | out_put_unused_fd: | |
407 | put_unused_fd(fd); | |
925ca369 | 408 | out_free_lh: |
883f9198 | 409 | linehandle_free(lh); |
925ca369 KG |
410 | return ret; |
411 | } | |
3c0d9c63 KG |
412 | #endif /* CONFIG_GPIO_CDEV_V1 */ |
413 | ||
414 | /** | |
415 | * struct line - contains the state of a requested line | |
9344e34e | 416 | * @node: to store the object in supinfo_tree if supplemental |
3c0d9c63 | 417 | * @desc: the GPIO descriptor for this line. |
73e03419 KG |
418 | * @req: the corresponding line request |
419 | * @irq: the interrupt triggered in response to events on this GPIO | |
8d259847 | 420 | * @edflags: the edge flags, GPIO_V2_LINE_FLAG_EDGE_RISING and/or |
73e03419 KG |
421 | * GPIO_V2_LINE_FLAG_EDGE_FALLING, indicating the edge detection applied |
422 | * @timestamp_ns: cache for the timestamp storing it between hardirq and | |
423 | * IRQ thread, used to bring the timestamp close to the actual event | |
424 | * @req_seqno: the seqno for the current edge event in the sequence of | |
425 | * events for the corresponding line request. This is drawn from the @req. | |
426 | * @line_seqno: the seqno for the current edge event in the sequence of | |
427 | * events for this line. | |
65cff704 | 428 | * @work: the worker that implements software debouncing |
9344e34e | 429 | * @debounce_period_us: the debounce period in microseconds |
65cff704 KG |
430 | * @sw_debounced: flag indicating if the software debouncer is active |
431 | * @level: the current debounced physical level of the line | |
85ff37e3 AS |
432 | * @hdesc: the Hardware Timestamp Engine (HTE) descriptor |
433 | * @raw_level: the line level at the time of event | |
434 | * @total_discard_seq: the running counter of the discarded events | |
435 | * @last_seqno: the last sequence number before debounce period expires | |
3c0d9c63 KG |
436 | */ |
437 | struct line { | |
9344e34e | 438 | struct rb_node node; |
3c0d9c63 | 439 | struct gpio_desc *desc; |
73e03419 KG |
440 | /* |
441 | * -- edge detector specific fields -- | |
442 | */ | |
443 | struct linereq *req; | |
444 | unsigned int irq; | |
3ffb7c45 | 445 | /* |
b1a92e94 KG |
446 | * The flags for the active edge detector configuration. |
447 | * | |
448 | * edflags is set by linereq_create(), linereq_free(), and | |
449 | * linereq_set_config_unlocked(), which are themselves mutually | |
450 | * exclusive, and is accessed by edge_irq_thread(), | |
451 | * process_hw_ts_thread() and debounce_work_func(), | |
452 | * which can all live with a slightly stale value. | |
3ffb7c45 | 453 | */ |
b1a92e94 | 454 | u64 edflags; |
73e03419 KG |
455 | /* |
456 | * timestamp_ns and req_seqno are accessed only by | |
457 | * edge_irq_handler() and edge_irq_thread(), which are themselves | |
458 | * mutually exclusive, so no additional protection is necessary. | |
459 | */ | |
460 | u64 timestamp_ns; | |
461 | u32 req_seqno; | |
65cff704 KG |
462 | /* |
463 | * line_seqno is accessed by either edge_irq_thread() or | |
464 | * debounce_work_func(), which are themselves mutually exclusive, | |
465 | * so no additional protection is necessary. | |
466 | */ | |
73e03419 | 467 | u32 line_seqno; |
65cff704 KG |
468 | /* |
469 | * -- debouncer specific fields -- | |
470 | */ | |
471 | struct delayed_work work; | |
9344e34e KG |
472 | /* |
473 | * debounce_period_us is accessed by debounce_irq_handler() and | |
474 | * process_hw_ts() which are disabled when modified by | |
475 | * debounce_setup(), edge_detector_setup() or edge_detector_stop() | |
476 | * or can live with a stale version when updated by | |
477 | * edge_detector_update(). | |
478 | * The modifying functions are themselves mutually exclusive. | |
479 | */ | |
480 | unsigned int debounce_period_us; | |
65cff704 KG |
481 | /* |
482 | * sw_debounce is accessed by linereq_set_config(), which is the | |
483 | * only setter, and linereq_get_values(), which can live with a | |
484 | * slightly stale value. | |
485 | */ | |
486 | unsigned int sw_debounced; | |
487 | /* | |
488 | * level is accessed by debounce_work_func(), which is the only | |
489 | * setter, and linereq_get_values() which can live with a slightly | |
490 | * stale value. | |
491 | */ | |
492 | unsigned int level; | |
272ddba0 | 493 | #ifdef CONFIG_HTE |
2068339a DP |
494 | struct hte_ts_desc hdesc; |
495 | /* | |
496 | * HTE provider sets line level at the time of event. The valid | |
497 | * value is 0 or 1 and negative value for an error. | |
498 | */ | |
499 | int raw_level; | |
500 | /* | |
501 | * when sw_debounce is set on HTE enabled line, this is running | |
502 | * counter of the discarded events. | |
503 | */ | |
504 | u32 total_discard_seq; | |
505 | /* | |
506 | * when sw_debounce is set on HTE enabled line, this variable records | |
507 | * last sequence number before debounce period expires. | |
508 | */ | |
509 | u32 last_seqno; | |
272ddba0 | 510 | #endif /* CONFIG_HTE */ |
3c0d9c63 KG |
511 | }; |
512 | ||
9344e34e KG |
513 | /* |
514 | * a rbtree of the struct lines containing supplemental info. | |
515 | * Used to populate gpio_v2_line_info with cdev specific fields not contained | |
516 | * in the struct gpio_desc. | |
517 | * A line is determined to contain supplemental information by | |
518 | * line_has_supinfo(). | |
519 | */ | |
520 | static struct rb_root supinfo_tree = RB_ROOT; | |
521 | /* covers supinfo_tree */ | |
522 | static DEFINE_SPINLOCK(supinfo_lock); | |
523 | ||
3c0d9c63 KG |
524 | /** |
525 | * struct linereq - contains the state of a userspace line request | |
526 | * @gdev: the GPIO device the line request pertains to | |
527 | * @label: consumer label used to tag GPIO descriptors | |
528 | * @num_lines: the number of lines in the lines array | |
73e03419 | 529 | * @wait: wait queue that handles blocking reads of events |
a0dda508 | 530 | * @device_unregistered_nb: notifier block for receiving gdev unregister events |
73e03419 KG |
531 | * @event_buffer_size: the number of elements allocated in @events |
532 | * @events: KFIFO for the GPIO events | |
533 | * @seqno: the sequence number for edge events generated on all lines in | |
534 | * this line request. Note that this is not used when @num_lines is 1, as | |
535 | * the line_seqno is then the same and is cheaper to calculate. | |
a54756cb | 536 | * @config_mutex: mutex for serializing ioctl() calls to ensure consistency |
9344e34e KG |
537 | * of configuration, particularly multi-step accesses to desc flags and |
538 | * changes to supinfo status. | |
3c0d9c63 KG |
539 | * @lines: the lines held by this line request, with @num_lines elements. |
540 | */ | |
541 | struct linereq { | |
542 | struct gpio_device *gdev; | |
543 | const char *label; | |
544 | u32 num_lines; | |
73e03419 | 545 | wait_queue_head_t wait; |
a0dda508 | 546 | struct notifier_block device_unregistered_nb; |
73e03419 KG |
547 | u32 event_buffer_size; |
548 | DECLARE_KFIFO_PTR(events, struct gpio_v2_line_event); | |
549 | atomic_t seqno; | |
a54756cb | 550 | struct mutex config_mutex; |
a512635d | 551 | struct line lines[] __counted_by(num_lines); |
3c0d9c63 KG |
552 | }; |
553 | ||
9344e34e KG |
554 | static void supinfo_insert(struct line *line) |
555 | { | |
556 | struct rb_node **new = &(supinfo_tree.rb_node), *parent = NULL; | |
557 | struct line *entry; | |
558 | ||
559 | guard(spinlock)(&supinfo_lock); | |
560 | ||
561 | while (*new) { | |
562 | entry = container_of(*new, struct line, node); | |
563 | ||
564 | parent = *new; | |
565 | if (line->desc < entry->desc) { | |
566 | new = &((*new)->rb_left); | |
567 | } else if (line->desc > entry->desc) { | |
568 | new = &((*new)->rb_right); | |
569 | } else { | |
570 | /* this should never happen */ | |
571 | WARN(1, "duplicate line inserted"); | |
572 | return; | |
573 | } | |
574 | } | |
575 | ||
576 | rb_link_node(&line->node, parent, new); | |
577 | rb_insert_color(&line->node, &supinfo_tree); | |
578 | } | |
579 | ||
580 | static void supinfo_erase(struct line *line) | |
581 | { | |
582 | guard(spinlock)(&supinfo_lock); | |
583 | ||
584 | rb_erase(&line->node, &supinfo_tree); | |
585 | } | |
586 | ||
587 | static struct line *supinfo_find(struct gpio_desc *desc) | |
588 | { | |
589 | struct rb_node *node = supinfo_tree.rb_node; | |
590 | struct line *line; | |
591 | ||
592 | while (node) { | |
593 | line = container_of(node, struct line, node); | |
594 | if (desc < line->desc) | |
595 | node = node->rb_left; | |
596 | else if (desc > line->desc) | |
597 | node = node->rb_right; | |
598 | else | |
599 | return line; | |
600 | } | |
601 | return NULL; | |
602 | } | |
603 | ||
604 | static void supinfo_to_lineinfo(struct gpio_desc *desc, | |
605 | struct gpio_v2_line_info *info) | |
606 | { | |
607 | struct gpio_v2_line_attribute *attr; | |
608 | struct line *line; | |
609 | ||
610 | guard(spinlock)(&supinfo_lock); | |
611 | ||
612 | line = supinfo_find(desc); | |
613 | if (!line) | |
614 | return; | |
615 | ||
616 | attr = &info->attrs[info->num_attrs]; | |
617 | attr->id = GPIO_V2_LINE_ATTR_ID_DEBOUNCE; | |
618 | attr->debounce_period_us = READ_ONCE(line->debounce_period_us); | |
619 | info->num_attrs++; | |
620 | } | |
621 | ||
622 | static inline bool line_has_supinfo(struct line *line) | |
623 | { | |
624 | return READ_ONCE(line->debounce_period_us); | |
625 | } | |
626 | ||
627 | /* | |
628 | * Checks line_has_supinfo() before and after the change to avoid unnecessary | |
629 | * supinfo_tree access. | |
630 | * Called indirectly by linereq_create() or linereq_set_config() so line | |
631 | * is already protected from concurrent changes. | |
632 | */ | |
633 | static void line_set_debounce_period(struct line *line, | |
634 | unsigned int debounce_period_us) | |
635 | { | |
636 | bool was_suppl = line_has_supinfo(line); | |
637 | ||
638 | WRITE_ONCE(line->debounce_period_us, debounce_period_us); | |
639 | ||
640 | /* if supinfo status is unchanged then we're done */ | |
641 | if (line_has_supinfo(line) == was_suppl) | |
642 | return; | |
643 | ||
644 | /* supinfo status has changed, so update the tree */ | |
645 | if (was_suppl) | |
646 | supinfo_erase(line); | |
647 | else | |
648 | supinfo_insert(line); | |
649 | } | |
650 | ||
3c0d9c63 KG |
651 | #define GPIO_V2_LINE_BIAS_FLAGS \ |
652 | (GPIO_V2_LINE_FLAG_BIAS_PULL_UP | \ | |
653 | GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN | \ | |
654 | GPIO_V2_LINE_FLAG_BIAS_DISABLED) | |
655 | ||
656 | #define GPIO_V2_LINE_DIRECTION_FLAGS \ | |
657 | (GPIO_V2_LINE_FLAG_INPUT | \ | |
658 | GPIO_V2_LINE_FLAG_OUTPUT) | |
659 | ||
660 | #define GPIO_V2_LINE_DRIVE_FLAGS \ | |
661 | (GPIO_V2_LINE_FLAG_OPEN_DRAIN | \ | |
662 | GPIO_V2_LINE_FLAG_OPEN_SOURCE) | |
663 | ||
73e03419 KG |
664 | #define GPIO_V2_LINE_EDGE_FLAGS \ |
665 | (GPIO_V2_LINE_FLAG_EDGE_RISING | \ | |
666 | GPIO_V2_LINE_FLAG_EDGE_FALLING) | |
667 | ||
5e2ca893 KG |
668 | #define GPIO_V2_LINE_FLAG_EDGE_BOTH GPIO_V2_LINE_EDGE_FLAGS |
669 | ||
3c0d9c63 KG |
670 | #define GPIO_V2_LINE_VALID_FLAGS \ |
671 | (GPIO_V2_LINE_FLAG_ACTIVE_LOW | \ | |
672 | GPIO_V2_LINE_DIRECTION_FLAGS | \ | |
673 | GPIO_V2_LINE_DRIVE_FLAGS | \ | |
73e03419 | 674 | GPIO_V2_LINE_EDGE_FLAGS | \ |
26d060e4 | 675 | GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME | \ |
2068339a | 676 | GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE | \ |
3c0d9c63 KG |
677 | GPIO_V2_LINE_BIAS_FLAGS) |
678 | ||
b1a92e94 KG |
679 | /* subset of flags relevant for edge detector configuration */ |
680 | #define GPIO_V2_LINE_EDGE_DETECTOR_FLAGS \ | |
681 | (GPIO_V2_LINE_FLAG_ACTIVE_LOW | \ | |
682 | GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE | \ | |
683 | GPIO_V2_LINE_EDGE_FLAGS) | |
684 | ||
a0dda508 BG |
685 | static int linereq_unregistered_notify(struct notifier_block *nb, |
686 | unsigned long action, void *data) | |
687 | { | |
688 | struct linereq *lr = container_of(nb, struct linereq, | |
689 | device_unregistered_nb); | |
690 | ||
691 | wake_up_poll(&lr->wait, EPOLLIN | EPOLLERR); | |
692 | ||
693 | return NOTIFY_OK; | |
694 | } | |
695 | ||
73e03419 KG |
696 | static void linereq_put_event(struct linereq *lr, |
697 | struct gpio_v2_line_event *le) | |
698 | { | |
699 | bool overflow = false; | |
700 | ||
0ebeaab4 KG |
701 | scoped_guard(spinlock, &lr->wait.lock) { |
702 | if (kfifo_is_full(&lr->events)) { | |
703 | overflow = true; | |
704 | kfifo_skip(&lr->events); | |
705 | } | |
706 | kfifo_in(&lr->events, le, 1); | |
73e03419 | 707 | } |
73e03419 KG |
708 | if (!overflow) |
709 | wake_up_poll(&lr->wait, EPOLLIN); | |
710 | else | |
711 | pr_debug_ratelimited("event FIFO is full - event dropped\n"); | |
712 | } | |
713 | ||
26d060e4 KG |
714 | static u64 line_event_timestamp(struct line *line) |
715 | { | |
716 | if (test_bit(FLAG_EVENT_CLOCK_REALTIME, &line->desc->flags)) | |
717 | return ktime_get_real_ns(); | |
272ddba0 KG |
718 | else if (IS_ENABLED(CONFIG_HTE) && |
719 | test_bit(FLAG_EVENT_CLOCK_HTE, &line->desc->flags)) | |
2068339a | 720 | return line->timestamp_ns; |
26d060e4 KG |
721 | |
722 | return ktime_get_ns(); | |
723 | } | |
724 | ||
24220232 KG |
725 | static u32 line_event_id(int level) |
726 | { | |
727 | return level ? GPIO_V2_LINE_EVENT_RISING_EDGE : | |
728 | GPIO_V2_LINE_EVENT_FALLING_EDGE; | |
729 | } | |
730 | ||
83092341 KG |
731 | static inline char *make_irq_label(const char *orig) |
732 | { | |
733 | char *new; | |
734 | ||
735 | if (!orig) | |
736 | return NULL; | |
737 | ||
738 | new = kstrdup_and_replace(orig, '/', ':', GFP_KERNEL); | |
739 | if (!new) | |
740 | return ERR_PTR(-ENOMEM); | |
741 | ||
742 | return new; | |
743 | } | |
744 | ||
745 | static inline void free_irq_label(const char *label) | |
746 | { | |
747 | kfree(label); | |
748 | } | |
749 | ||
272ddba0 KG |
750 | #ifdef CONFIG_HTE |
751 | ||
2068339a DP |
752 | static enum hte_return process_hw_ts_thread(void *p) |
753 | { | |
754 | struct line *line; | |
755 | struct linereq *lr; | |
756 | struct gpio_v2_line_event le; | |
b1a92e94 | 757 | u64 edflags; |
2068339a | 758 | int level; |
2068339a DP |
759 | |
760 | if (!p) | |
761 | return HTE_CB_HANDLED; | |
762 | ||
763 | line = p; | |
764 | lr = line->req; | |
765 | ||
766 | memset(&le, 0, sizeof(le)); | |
767 | ||
768 | le.timestamp_ns = line->timestamp_ns; | |
b1a92e94 | 769 | edflags = READ_ONCE(line->edflags); |
2068339a | 770 | |
b1a92e94 | 771 | switch (edflags & GPIO_V2_LINE_EDGE_FLAGS) { |
cfa53463 | 772 | case GPIO_V2_LINE_FLAG_EDGE_BOTH: |
24220232 KG |
773 | level = (line->raw_level >= 0) ? |
774 | line->raw_level : | |
775 | gpiod_get_raw_value_cansleep(line->desc); | |
776 | ||
b1a92e94 | 777 | if (edflags & GPIO_V2_LINE_FLAG_ACTIVE_LOW) |
24220232 | 778 | level = !level; |
2068339a | 779 | |
24220232 | 780 | le.id = line_event_id(level); |
cfa53463 KG |
781 | break; |
782 | case GPIO_V2_LINE_FLAG_EDGE_RISING: | |
2068339a | 783 | le.id = GPIO_V2_LINE_EVENT_RISING_EDGE; |
cfa53463 KG |
784 | break; |
785 | case GPIO_V2_LINE_FLAG_EDGE_FALLING: | |
2068339a | 786 | le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE; |
cfa53463 KG |
787 | break; |
788 | default: | |
2068339a DP |
789 | return HTE_CB_HANDLED; |
790 | } | |
791 | le.line_seqno = line->line_seqno; | |
792 | le.seqno = (lr->num_lines == 1) ? le.line_seqno : line->req_seqno; | |
793 | le.offset = gpio_chip_hwgpio(line->desc); | |
794 | ||
795 | linereq_put_event(lr, &le); | |
796 | ||
797 | return HTE_CB_HANDLED; | |
798 | } | |
799 | ||
800 | static enum hte_return process_hw_ts(struct hte_ts_data *ts, void *p) | |
801 | { | |
802 | struct line *line; | |
803 | struct linereq *lr; | |
804 | int diff_seqno = 0; | |
805 | ||
806 | if (!ts || !p) | |
807 | return HTE_CB_HANDLED; | |
808 | ||
809 | line = p; | |
810 | line->timestamp_ns = ts->tsc; | |
811 | line->raw_level = ts->raw_level; | |
812 | lr = line->req; | |
813 | ||
814 | if (READ_ONCE(line->sw_debounced)) { | |
815 | line->total_discard_seq++; | |
816 | line->last_seqno = ts->seq; | |
817 | mod_delayed_work(system_wq, &line->work, | |
9344e34e | 818 | usecs_to_jiffies(READ_ONCE(line->debounce_period_us))); |
2068339a DP |
819 | } else { |
820 | if (unlikely(ts->seq < line->line_seqno)) | |
821 | return HTE_CB_HANDLED; | |
822 | ||
823 | diff_seqno = ts->seq - line->line_seqno; | |
824 | line->line_seqno = ts->seq; | |
825 | if (lr->num_lines != 1) | |
826 | line->req_seqno = atomic_add_return(diff_seqno, | |
827 | &lr->seqno); | |
828 | ||
829 | return HTE_RUN_SECOND_CB; | |
830 | } | |
831 | ||
832 | return HTE_CB_HANDLED; | |
833 | } | |
834 | ||
272ddba0 KG |
835 | static int hte_edge_setup(struct line *line, u64 eflags) |
836 | { | |
837 | int ret; | |
838 | unsigned long flags = 0; | |
839 | struct hte_ts_desc *hdesc = &line->hdesc; | |
840 | ||
841 | if (eflags & GPIO_V2_LINE_FLAG_EDGE_RISING) | |
842 | flags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ? | |
843 | HTE_FALLING_EDGE_TS : | |
844 | HTE_RISING_EDGE_TS; | |
845 | if (eflags & GPIO_V2_LINE_FLAG_EDGE_FALLING) | |
846 | flags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ? | |
847 | HTE_RISING_EDGE_TS : | |
848 | HTE_FALLING_EDGE_TS; | |
849 | ||
850 | line->total_discard_seq = 0; | |
851 | ||
852 | hte_init_line_attr(hdesc, desc_to_gpio(line->desc), flags, NULL, | |
853 | line->desc); | |
854 | ||
855 | ret = hte_ts_get(NULL, hdesc, 0); | |
856 | if (ret) | |
857 | return ret; | |
858 | ||
859 | return hte_request_ts_ns(hdesc, process_hw_ts, process_hw_ts_thread, | |
860 | line); | |
861 | } | |
862 | ||
863 | #else | |
864 | ||
865 | static int hte_edge_setup(struct line *line, u64 eflags) | |
866 | { | |
867 | return 0; | |
868 | } | |
869 | #endif /* CONFIG_HTE */ | |
870 | ||
73e03419 KG |
871 | static irqreturn_t edge_irq_thread(int irq, void *p) |
872 | { | |
873 | struct line *line = p; | |
874 | struct linereq *lr = line->req; | |
875 | struct gpio_v2_line_event le; | |
876 | ||
877 | /* Do not leak kernel stack to userspace */ | |
878 | memset(&le, 0, sizeof(le)); | |
879 | ||
880 | if (line->timestamp_ns) { | |
881 | le.timestamp_ns = line->timestamp_ns; | |
882 | } else { | |
883 | /* | |
884 | * We may be running from a nested threaded interrupt in | |
885 | * which case we didn't get the timestamp from | |
886 | * edge_irq_handler(). | |
887 | */ | |
26d060e4 | 888 | le.timestamp_ns = line_event_timestamp(line); |
73e03419 KG |
889 | if (lr->num_lines != 1) |
890 | line->req_seqno = atomic_inc_return(&lr->seqno); | |
891 | } | |
892 | line->timestamp_ns = 0; | |
893 | ||
b1a92e94 | 894 | switch (READ_ONCE(line->edflags) & GPIO_V2_LINE_EDGE_FLAGS) { |
cfa53463 | 895 | case GPIO_V2_LINE_FLAG_EDGE_BOTH: |
24220232 | 896 | le.id = line_event_id(gpiod_get_value_cansleep(line->desc)); |
cfa53463 KG |
897 | break; |
898 | case GPIO_V2_LINE_FLAG_EDGE_RISING: | |
73e03419 | 899 | le.id = GPIO_V2_LINE_EVENT_RISING_EDGE; |
cfa53463 KG |
900 | break; |
901 | case GPIO_V2_LINE_FLAG_EDGE_FALLING: | |
73e03419 | 902 | le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE; |
cfa53463 KG |
903 | break; |
904 | default: | |
73e03419 KG |
905 | return IRQ_NONE; |
906 | } | |
907 | line->line_seqno++; | |
908 | le.line_seqno = line->line_seqno; | |
909 | le.seqno = (lr->num_lines == 1) ? le.line_seqno : line->req_seqno; | |
910 | le.offset = gpio_chip_hwgpio(line->desc); | |
911 | ||
912 | linereq_put_event(lr, &le); | |
913 | ||
914 | return IRQ_HANDLED; | |
915 | } | |
916 | ||
917 | static irqreturn_t edge_irq_handler(int irq, void *p) | |
918 | { | |
919 | struct line *line = p; | |
920 | struct linereq *lr = line->req; | |
921 | ||
922 | /* | |
923 | * Just store the timestamp in hardirq context so we get it as | |
924 | * close in time as possible to the actual event. | |
925 | */ | |
26d060e4 | 926 | line->timestamp_ns = line_event_timestamp(line); |
73e03419 KG |
927 | |
928 | if (lr->num_lines != 1) | |
929 | line->req_seqno = atomic_inc_return(&lr->seqno); | |
930 | ||
931 | return IRQ_WAKE_THREAD; | |
932 | } | |
933 | ||
65cff704 KG |
934 | /* |
935 | * returns the current debounced logical value. | |
936 | */ | |
937 | static bool debounced_value(struct line *line) | |
938 | { | |
939 | bool value; | |
940 | ||
941 | /* | |
942 | * minor race - debouncer may be stopped here, so edge_detector_stop() | |
943 | * must leave the value unchanged so the following will read the level | |
944 | * from when the debouncer was last running. | |
945 | */ | |
946 | value = READ_ONCE(line->level); | |
947 | ||
948 | if (test_bit(FLAG_ACTIVE_LOW, &line->desc->flags)) | |
949 | value = !value; | |
950 | ||
951 | return value; | |
952 | } | |
953 | ||
954 | static irqreturn_t debounce_irq_handler(int irq, void *p) | |
955 | { | |
956 | struct line *line = p; | |
957 | ||
958 | mod_delayed_work(system_wq, &line->work, | |
9344e34e | 959 | usecs_to_jiffies(READ_ONCE(line->debounce_period_us))); |
65cff704 KG |
960 | |
961 | return IRQ_HANDLED; | |
962 | } | |
963 | ||
964 | static void debounce_work_func(struct work_struct *work) | |
965 | { | |
966 | struct gpio_v2_line_event le; | |
967 | struct line *line = container_of(work, struct line, work.work); | |
968 | struct linereq *lr; | |
b1a92e94 | 969 | u64 eflags, edflags = READ_ONCE(line->edflags); |
272ddba0 KG |
970 | int level = -1; |
971 | #ifdef CONFIG_HTE | |
972 | int diff_seqno; | |
65cff704 | 973 | |
b1a92e94 | 974 | if (edflags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE) |
2068339a | 975 | level = line->raw_level; |
272ddba0 | 976 | #endif |
b1a92e94 | 977 | if (level < 0) |
2068339a | 978 | level = gpiod_get_raw_value_cansleep(line->desc); |
65cff704 KG |
979 | if (level < 0) { |
980 | pr_debug_ratelimited("debouncer failed to read line value\n"); | |
981 | return; | |
982 | } | |
983 | ||
984 | if (READ_ONCE(line->level) == level) | |
985 | return; | |
986 | ||
987 | WRITE_ONCE(line->level, level); | |
988 | ||
989 | /* -- edge detection -- */ | |
b1a92e94 | 990 | eflags = edflags & GPIO_V2_LINE_EDGE_FLAGS; |
3ffb7c45 | 991 | if (!eflags) |
65cff704 KG |
992 | return; |
993 | ||
994 | /* switch from physical level to logical - if they differ */ | |
b1a92e94 | 995 | if (edflags & GPIO_V2_LINE_FLAG_ACTIVE_LOW) |
65cff704 KG |
996 | level = !level; |
997 | ||
998 | /* ignore edges that are not being monitored */ | |
3ffb7c45 KG |
999 | if (((eflags == GPIO_V2_LINE_FLAG_EDGE_RISING) && !level) || |
1000 | ((eflags == GPIO_V2_LINE_FLAG_EDGE_FALLING) && level)) | |
65cff704 KG |
1001 | return; |
1002 | ||
1003 | /* Do not leak kernel stack to userspace */ | |
1004 | memset(&le, 0, sizeof(le)); | |
1005 | ||
1006 | lr = line->req; | |
26d060e4 | 1007 | le.timestamp_ns = line_event_timestamp(line); |
65cff704 | 1008 | le.offset = gpio_chip_hwgpio(line->desc); |
272ddba0 | 1009 | #ifdef CONFIG_HTE |
b1a92e94 | 1010 | if (edflags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE) { |
2068339a DP |
1011 | /* discard events except the last one */ |
1012 | line->total_discard_seq -= 1; | |
1013 | diff_seqno = line->last_seqno - line->total_discard_seq - | |
1014 | line->line_seqno; | |
1015 | line->line_seqno = line->last_seqno - line->total_discard_seq; | |
1016 | le.line_seqno = line->line_seqno; | |
1017 | le.seqno = (lr->num_lines == 1) ? | |
1018 | le.line_seqno : atomic_add_return(diff_seqno, &lr->seqno); | |
272ddba0 KG |
1019 | } else |
1020 | #endif /* CONFIG_HTE */ | |
1021 | { | |
2068339a DP |
1022 | line->line_seqno++; |
1023 | le.line_seqno = line->line_seqno; | |
1024 | le.seqno = (lr->num_lines == 1) ? | |
1025 | le.line_seqno : atomic_inc_return(&lr->seqno); | |
1026 | } | |
65cff704 | 1027 | |
24220232 | 1028 | le.id = line_event_id(level); |
65cff704 KG |
1029 | |
1030 | linereq_put_event(lr, &le); | |
1031 | } | |
1032 | ||
b1a92e94 | 1033 | static int debounce_setup(struct line *line, unsigned int debounce_period_us) |
65cff704 KG |
1034 | { |
1035 | unsigned long irqflags; | |
1036 | int ret, level, irq; | |
83092341 | 1037 | char *label; |
65cff704 KG |
1038 | |
1039 | /* try hardware */ | |
1040 | ret = gpiod_set_debounce(line->desc, debounce_period_us); | |
1041 | if (!ret) { | |
9344e34e | 1042 | line_set_debounce_period(line, debounce_period_us); |
65cff704 KG |
1043 | return ret; |
1044 | } | |
1045 | if (ret != -ENOTSUPP) | |
1046 | return ret; | |
1047 | ||
1048 | if (debounce_period_us) { | |
1049 | /* setup software debounce */ | |
1050 | level = gpiod_get_raw_value_cansleep(line->desc); | |
1051 | if (level < 0) | |
1052 | return level; | |
1053 | ||
272ddba0 KG |
1054 | if (!(IS_ENABLED(CONFIG_HTE) && |
1055 | test_bit(FLAG_EVENT_CLOCK_HTE, &line->desc->flags))) { | |
2068339a DP |
1056 | irq = gpiod_to_irq(line->desc); |
1057 | if (irq < 0) | |
1058 | return -ENXIO; | |
65cff704 | 1059 | |
83092341 KG |
1060 | label = make_irq_label(line->req->label); |
1061 | if (IS_ERR(label)) | |
1062 | return -ENOMEM; | |
1063 | ||
2068339a DP |
1064 | irqflags = IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING; |
1065 | ret = request_irq(irq, debounce_irq_handler, irqflags, | |
83092341 KG |
1066 | label, line); |
1067 | if (ret) { | |
1068 | free_irq_label(label); | |
2068339a | 1069 | return ret; |
83092341 | 1070 | } |
2068339a DP |
1071 | line->irq = irq; |
1072 | } else { | |
2487a812 | 1073 | ret = hte_edge_setup(line, GPIO_V2_LINE_FLAG_EDGE_BOTH); |
2068339a DP |
1074 | if (ret) |
1075 | return ret; | |
1076 | } | |
65cff704 | 1077 | |
2068339a | 1078 | WRITE_ONCE(line->level, level); |
65cff704 | 1079 | WRITE_ONCE(line->sw_debounced, 1); |
65cff704 KG |
1080 | } |
1081 | return 0; | |
1082 | } | |
1083 | ||
1084 | static bool gpio_v2_line_config_debounced(struct gpio_v2_line_config *lc, | |
1085 | unsigned int line_idx) | |
1086 | { | |
1087 | unsigned int i; | |
1088 | u64 mask = BIT_ULL(line_idx); | |
1089 | ||
1090 | for (i = 0; i < lc->num_attrs; i++) { | |
1091 | if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_DEBOUNCE) && | |
1092 | (lc->attrs[i].mask & mask)) | |
1093 | return true; | |
1094 | } | |
1095 | return false; | |
1096 | } | |
1097 | ||
1098 | static u32 gpio_v2_line_config_debounce_period(struct gpio_v2_line_config *lc, | |
1099 | unsigned int line_idx) | |
1100 | { | |
1101 | unsigned int i; | |
1102 | u64 mask = BIT_ULL(line_idx); | |
1103 | ||
1104 | for (i = 0; i < lc->num_attrs; i++) { | |
1105 | if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_DEBOUNCE) && | |
1106 | (lc->attrs[i].mask & mask)) | |
1107 | return lc->attrs[i].attr.debounce_period_us; | |
1108 | } | |
1109 | return 0; | |
1110 | } | |
1111 | ||
b1a92e94 | 1112 | static void edge_detector_stop(struct line *line) |
73e03419 | 1113 | { |
b1a92e94 | 1114 | if (line->irq) { |
b3449087 | 1115 | free_irq_label(free_irq(line->irq, line)); |
73e03419 KG |
1116 | line->irq = 0; |
1117 | } | |
a54756cb | 1118 | |
272ddba0 | 1119 | #ifdef CONFIG_HTE |
b1a92e94 | 1120 | if (READ_ONCE(line->edflags) & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE) |
2068339a | 1121 | hte_ts_put(&line->hdesc); |
272ddba0 | 1122 | #endif |
2068339a | 1123 | |
65cff704 KG |
1124 | cancel_delayed_work_sync(&line->work); |
1125 | WRITE_ONCE(line->sw_debounced, 0); | |
b1a92e94 | 1126 | WRITE_ONCE(line->edflags, 0); |
9344e34e | 1127 | line_set_debounce_period(line, 0); |
65cff704 | 1128 | /* do not change line->level - see comment in debounced_value() */ |
73e03419 KG |
1129 | } |
1130 | ||
1131 | static int edge_detector_setup(struct line *line, | |
65cff704 | 1132 | struct gpio_v2_line_config *lc, |
b1a92e94 | 1133 | unsigned int line_idx, u64 edflags) |
73e03419 | 1134 | { |
65cff704 | 1135 | u32 debounce_period_us; |
73e03419 | 1136 | unsigned long irqflags = 0; |
b1a92e94 | 1137 | u64 eflags; |
73e03419 | 1138 | int irq, ret; |
b3449087 | 1139 | char *label; |
73e03419 | 1140 | |
b1a92e94 | 1141 | eflags = edflags & GPIO_V2_LINE_EDGE_FLAGS; |
73e03419 KG |
1142 | if (eflags && !kfifo_initialized(&line->req->events)) { |
1143 | ret = kfifo_alloc(&line->req->events, | |
1144 | line->req->event_buffer_size, GFP_KERNEL); | |
1145 | if (ret) | |
1146 | return ret; | |
1147 | } | |
65cff704 KG |
1148 | if (gpio_v2_line_config_debounced(lc, line_idx)) { |
1149 | debounce_period_us = gpio_v2_line_config_debounce_period(lc, line_idx); | |
b1a92e94 | 1150 | ret = debounce_setup(line, debounce_period_us); |
65cff704 KG |
1151 | if (ret) |
1152 | return ret; | |
9344e34e | 1153 | line_set_debounce_period(line, debounce_period_us); |
65cff704 | 1154 | } |
73e03419 | 1155 | |
65cff704 KG |
1156 | /* detection disabled or sw debouncer will provide edge detection */ |
1157 | if (!eflags || READ_ONCE(line->sw_debounced)) | |
73e03419 KG |
1158 | return 0; |
1159 | ||
272ddba0 KG |
1160 | if (IS_ENABLED(CONFIG_HTE) && |
1161 | (edflags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE)) | |
b1a92e94 | 1162 | return hte_edge_setup(line, edflags); |
2068339a | 1163 | |
73e03419 KG |
1164 | irq = gpiod_to_irq(line->desc); |
1165 | if (irq < 0) | |
1166 | return -ENXIO; | |
1167 | ||
1168 | if (eflags & GPIO_V2_LINE_FLAG_EDGE_RISING) | |
1169 | irqflags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ? | |
1170 | IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; | |
1171 | if (eflags & GPIO_V2_LINE_FLAG_EDGE_FALLING) | |
1172 | irqflags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ? | |
1173 | IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING; | |
1174 | irqflags |= IRQF_ONESHOT; | |
1175 | ||
b3449087 | 1176 | label = make_irq_label(line->req->label); |
b3b95964 BG |
1177 | if (IS_ERR(label)) |
1178 | return PTR_ERR(label); | |
b3449087 | 1179 | |
73e03419 KG |
1180 | /* Request a thread to read the events */ |
1181 | ret = request_threaded_irq(irq, edge_irq_handler, edge_irq_thread, | |
b3449087 BG |
1182 | irqflags, label, line); |
1183 | if (ret) { | |
1184 | free_irq_label(label); | |
73e03419 | 1185 | return ret; |
b3449087 | 1186 | } |
73e03419 KG |
1187 | |
1188 | line->irq = irq; | |
1189 | return 0; | |
1190 | } | |
1191 | ||
65cff704 KG |
1192 | static int edge_detector_update(struct line *line, |
1193 | struct gpio_v2_line_config *lc, | |
b1a92e94 | 1194 | unsigned int line_idx, u64 edflags) |
a54756cb | 1195 | { |
ee0166b6 KG |
1196 | u64 eflags; |
1197 | int ret; | |
b1a92e94 | 1198 | u64 active_edflags = READ_ONCE(line->edflags); |
65cff704 | 1199 | unsigned int debounce_period_us = |
2068339a | 1200 | gpio_v2_line_config_debounce_period(lc, line_idx); |
65cff704 | 1201 | |
b1a92e94 | 1202 | if ((active_edflags == edflags) && |
9344e34e | 1203 | (READ_ONCE(line->debounce_period_us) == debounce_period_us)) |
65cff704 KG |
1204 | return 0; |
1205 | ||
1206 | /* sw debounced and still will be...*/ | |
1207 | if (debounce_period_us && READ_ONCE(line->sw_debounced)) { | |
9344e34e | 1208 | line_set_debounce_period(line, debounce_period_us); |
ee0166b6 KG |
1209 | /* |
1210 | * ensure event fifo is initialised if edge detection | |
1211 | * is now enabled. | |
1212 | */ | |
1213 | eflags = edflags & GPIO_V2_LINE_EDGE_FLAGS; | |
1214 | if (eflags && !kfifo_initialized(&line->req->events)) { | |
1215 | ret = kfifo_alloc(&line->req->events, | |
1216 | line->req->event_buffer_size, | |
1217 | GFP_KERNEL); | |
1218 | if (ret) | |
1219 | return ret; | |
1220 | } | |
a54756cb | 1221 | return 0; |
65cff704 | 1222 | } |
a54756cb | 1223 | |
65cff704 | 1224 | /* reconfiguring edge detection or sw debounce being disabled */ |
b1a92e94 KG |
1225 | if ((line->irq && !READ_ONCE(line->sw_debounced)) || |
1226 | (active_edflags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE) || | |
65cff704 | 1227 | (!debounce_period_us && READ_ONCE(line->sw_debounced))) |
b1a92e94 | 1228 | edge_detector_stop(line); |
a54756cb | 1229 | |
b1a92e94 | 1230 | return edge_detector_setup(line, lc, line_idx, edflags); |
a54756cb KG |
1231 | } |
1232 | ||
3c0d9c63 KG |
1233 | static u64 gpio_v2_line_config_flags(struct gpio_v2_line_config *lc, |
1234 | unsigned int line_idx) | |
1235 | { | |
1236 | unsigned int i; | |
1237 | u64 mask = BIT_ULL(line_idx); | |
1238 | ||
1239 | for (i = 0; i < lc->num_attrs; i++) { | |
1240 | if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_FLAGS) && | |
1241 | (lc->attrs[i].mask & mask)) | |
1242 | return lc->attrs[i].attr.flags; | |
1243 | } | |
1244 | return lc->flags; | |
1245 | } | |
1246 | ||
1247 | static int gpio_v2_line_config_output_value(struct gpio_v2_line_config *lc, | |
1248 | unsigned int line_idx) | |
1249 | { | |
1250 | unsigned int i; | |
1251 | u64 mask = BIT_ULL(line_idx); | |
1252 | ||
1253 | for (i = 0; i < lc->num_attrs; i++) { | |
1254 | if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES) && | |
1255 | (lc->attrs[i].mask & mask)) | |
1256 | return !!(lc->attrs[i].attr.values & mask); | |
1257 | } | |
1258 | return 0; | |
1259 | } | |
1260 | ||
1261 | static int gpio_v2_line_flags_validate(u64 flags) | |
1262 | { | |
1263 | /* Return an error if an unknown flag is set */ | |
1264 | if (flags & ~GPIO_V2_LINE_VALID_FLAGS) | |
1265 | return -EINVAL; | |
272ddba0 KG |
1266 | |
1267 | if (!IS_ENABLED(CONFIG_HTE) && | |
1268 | (flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE)) | |
1269 | return -EOPNOTSUPP; | |
1270 | ||
3c0d9c63 KG |
1271 | /* |
1272 | * Do not allow both INPUT and OUTPUT flags to be set as they are | |
1273 | * contradictory. | |
1274 | */ | |
1275 | if ((flags & GPIO_V2_LINE_FLAG_INPUT) && | |
1276 | (flags & GPIO_V2_LINE_FLAG_OUTPUT)) | |
1277 | return -EINVAL; | |
1278 | ||
2068339a | 1279 | /* Only allow one event clock source */ |
272ddba0 KG |
1280 | if (IS_ENABLED(CONFIG_HTE) && |
1281 | (flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME) && | |
2068339a DP |
1282 | (flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE)) |
1283 | return -EINVAL; | |
1284 | ||
73e03419 KG |
1285 | /* Edge detection requires explicit input. */ |
1286 | if ((flags & GPIO_V2_LINE_EDGE_FLAGS) && | |
1287 | !(flags & GPIO_V2_LINE_FLAG_INPUT)) | |
1288 | return -EINVAL; | |
1289 | ||
3c0d9c63 KG |
1290 | /* |
1291 | * Do not allow OPEN_SOURCE and OPEN_DRAIN flags in a single | |
1292 | * request. If the hardware actually supports enabling both at the | |
1293 | * same time the electrical result would be disastrous. | |
1294 | */ | |
1295 | if ((flags & GPIO_V2_LINE_FLAG_OPEN_DRAIN) && | |
1296 | (flags & GPIO_V2_LINE_FLAG_OPEN_SOURCE)) | |
1297 | return -EINVAL; | |
1298 | ||
1299 | /* Drive requires explicit output direction. */ | |
1300 | if ((flags & GPIO_V2_LINE_DRIVE_FLAGS) && | |
1301 | !(flags & GPIO_V2_LINE_FLAG_OUTPUT)) | |
1302 | return -EINVAL; | |
1303 | ||
1304 | /* Bias requires explicit direction. */ | |
1305 | if ((flags & GPIO_V2_LINE_BIAS_FLAGS) && | |
1306 | !(flags & GPIO_V2_LINE_DIRECTION_FLAGS)) | |
1307 | return -EINVAL; | |
1308 | ||
1309 | /* Only one bias flag can be set. */ | |
1310 | if (((flags & GPIO_V2_LINE_FLAG_BIAS_DISABLED) && | |
1311 | (flags & (GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN | | |
1312 | GPIO_V2_LINE_FLAG_BIAS_PULL_UP))) || | |
1313 | ((flags & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN) && | |
1314 | (flags & GPIO_V2_LINE_FLAG_BIAS_PULL_UP))) | |
1315 | return -EINVAL; | |
1316 | ||
1317 | return 0; | |
1318 | } | |
1319 | ||
1320 | static int gpio_v2_line_config_validate(struct gpio_v2_line_config *lc, | |
1321 | unsigned int num_lines) | |
1322 | { | |
1323 | unsigned int i; | |
1324 | u64 flags; | |
1325 | int ret; | |
1326 | ||
1327 | if (lc->num_attrs > GPIO_V2_LINE_NUM_ATTRS_MAX) | |
1328 | return -EINVAL; | |
1329 | ||
1330 | if (memchr_inv(lc->padding, 0, sizeof(lc->padding))) | |
1331 | return -EINVAL; | |
1332 | ||
1333 | for (i = 0; i < num_lines; i++) { | |
1334 | flags = gpio_v2_line_config_flags(lc, i); | |
1335 | ret = gpio_v2_line_flags_validate(flags); | |
1336 | if (ret) | |
1337 | return ret; | |
65cff704 KG |
1338 | |
1339 | /* debounce requires explicit input */ | |
1340 | if (gpio_v2_line_config_debounced(lc, i) && | |
1341 | !(flags & GPIO_V2_LINE_FLAG_INPUT)) | |
1342 | return -EINVAL; | |
3c0d9c63 KG |
1343 | } |
1344 | return 0; | |
1345 | } | |
1346 | ||
1347 | static void gpio_v2_line_config_flags_to_desc_flags(u64 flags, | |
1348 | unsigned long *flagsp) | |
1349 | { | |
1350 | assign_bit(FLAG_ACTIVE_LOW, flagsp, | |
1351 | flags & GPIO_V2_LINE_FLAG_ACTIVE_LOW); | |
1352 | ||
1353 | if (flags & GPIO_V2_LINE_FLAG_OUTPUT) | |
1354 | set_bit(FLAG_IS_OUT, flagsp); | |
1355 | else if (flags & GPIO_V2_LINE_FLAG_INPUT) | |
1356 | clear_bit(FLAG_IS_OUT, flagsp); | |
1357 | ||
73e03419 KG |
1358 | assign_bit(FLAG_EDGE_RISING, flagsp, |
1359 | flags & GPIO_V2_LINE_FLAG_EDGE_RISING); | |
1360 | assign_bit(FLAG_EDGE_FALLING, flagsp, | |
1361 | flags & GPIO_V2_LINE_FLAG_EDGE_FALLING); | |
1362 | ||
3c0d9c63 KG |
1363 | assign_bit(FLAG_OPEN_DRAIN, flagsp, |
1364 | flags & GPIO_V2_LINE_FLAG_OPEN_DRAIN); | |
1365 | assign_bit(FLAG_OPEN_SOURCE, flagsp, | |
1366 | flags & GPIO_V2_LINE_FLAG_OPEN_SOURCE); | |
1367 | ||
1368 | assign_bit(FLAG_PULL_UP, flagsp, | |
1369 | flags & GPIO_V2_LINE_FLAG_BIAS_PULL_UP); | |
1370 | assign_bit(FLAG_PULL_DOWN, flagsp, | |
1371 | flags & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN); | |
1372 | assign_bit(FLAG_BIAS_DISABLE, flagsp, | |
1373 | flags & GPIO_V2_LINE_FLAG_BIAS_DISABLED); | |
26d060e4 KG |
1374 | |
1375 | assign_bit(FLAG_EVENT_CLOCK_REALTIME, flagsp, | |
1376 | flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME); | |
2068339a DP |
1377 | assign_bit(FLAG_EVENT_CLOCK_HTE, flagsp, |
1378 | flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE); | |
3c0d9c63 KG |
1379 | } |
1380 | ||
1381 | static long linereq_get_values(struct linereq *lr, void __user *ip) | |
1382 | { | |
1383 | struct gpio_v2_line_values lv; | |
1384 | DECLARE_BITMAP(vals, GPIO_V2_LINES_MAX); | |
1385 | struct gpio_desc **descs; | |
1386 | unsigned int i, didx, num_get; | |
65cff704 | 1387 | bool val; |
3c0d9c63 KG |
1388 | int ret; |
1389 | ||
1390 | /* NOTE: It's ok to read values of output lines. */ | |
1391 | if (copy_from_user(&lv, ip, sizeof(lv))) | |
1392 | return -EFAULT; | |
1393 | ||
193b6b09 KG |
1394 | /* |
1395 | * gpiod_get_array_value_complex() requires compacted desc and val | |
1396 | * arrays, rather than the sparse ones in lv. | |
1397 | * Calculation of num_get and construction of the desc array is | |
1398 | * optimized to avoid allocation for the desc array for the common | |
1399 | * num_get == 1 case. | |
1400 | */ | |
1401 | /* scan requested lines to calculate the subset to get */ | |
3c0d9c63 KG |
1402 | for (num_get = 0, i = 0; i < lr->num_lines; i++) { |
1403 | if (lv.mask & BIT_ULL(i)) { | |
1404 | num_get++; | |
193b6b09 | 1405 | /* capture desc for the num_get == 1 case */ |
3c0d9c63 KG |
1406 | descs = &lr->lines[i].desc; |
1407 | } | |
1408 | } | |
1409 | ||
1410 | if (num_get == 0) | |
1411 | return -EINVAL; | |
1412 | ||
1413 | if (num_get != 1) { | |
193b6b09 | 1414 | /* build compacted desc array */ |
3c0d9c63 KG |
1415 | descs = kmalloc_array(num_get, sizeof(*descs), GFP_KERNEL); |
1416 | if (!descs) | |
1417 | return -ENOMEM; | |
1418 | for (didx = 0, i = 0; i < lr->num_lines; i++) { | |
1419 | if (lv.mask & BIT_ULL(i)) { | |
1420 | descs[didx] = lr->lines[i].desc; | |
1421 | didx++; | |
1422 | } | |
1423 | } | |
1424 | } | |
1425 | ret = gpiod_get_array_value_complex(false, true, num_get, | |
1426 | descs, NULL, vals); | |
1427 | ||
1428 | if (num_get != 1) | |
1429 | kfree(descs); | |
1430 | if (ret) | |
1431 | return ret; | |
1432 | ||
1433 | lv.bits = 0; | |
1434 | for (didx = 0, i = 0; i < lr->num_lines; i++) { | |
193b6b09 | 1435 | /* unpack compacted vals for the response */ |
3c0d9c63 | 1436 | if (lv.mask & BIT_ULL(i)) { |
65cff704 KG |
1437 | if (lr->lines[i].sw_debounced) |
1438 | val = debounced_value(&lr->lines[i]); | |
1439 | else | |
1440 | val = test_bit(didx, vals); | |
1441 | if (val) | |
3c0d9c63 KG |
1442 | lv.bits |= BIT_ULL(i); |
1443 | didx++; | |
1444 | } | |
1445 | } | |
1446 | ||
1447 | if (copy_to_user(ip, &lv, sizeof(lv))) | |
1448 | return -EFAULT; | |
1449 | ||
1450 | return 0; | |
1451 | } | |
1452 | ||
32d8e3b6 | 1453 | static long linereq_set_values(struct linereq *lr, void __user *ip) |
7b8e00d9 KG |
1454 | { |
1455 | DECLARE_BITMAP(vals, GPIO_V2_LINES_MAX); | |
32d8e3b6 | 1456 | struct gpio_v2_line_values lv; |
7b8e00d9 KG |
1457 | struct gpio_desc **descs; |
1458 | unsigned int i, didx, num_set; | |
1459 | int ret; | |
1460 | ||
32d8e3b6 KG |
1461 | if (copy_from_user(&lv, ip, sizeof(lv))) |
1462 | return -EFAULT; | |
1463 | ||
1464 | guard(mutex)(&lr->config_mutex); | |
1465 | ||
193b6b09 KG |
1466 | /* |
1467 | * gpiod_set_array_value_complex() requires compacted desc and val | |
1468 | * arrays, rather than the sparse ones in lv. | |
1469 | * Calculation of num_set and construction of the descs and vals arrays | |
1470 | * is optimized to minimize scanning the lv->mask, and to avoid | |
1471 | * allocation for the desc array for the common num_set == 1 case. | |
1472 | */ | |
7b8e00d9 | 1473 | bitmap_zero(vals, GPIO_V2_LINES_MAX); |
193b6b09 | 1474 | /* scan requested lines to determine the subset to be set */ |
7b8e00d9 | 1475 | for (num_set = 0, i = 0; i < lr->num_lines; i++) { |
32d8e3b6 | 1476 | if (lv.mask & BIT_ULL(i)) { |
193b6b09 | 1477 | /* setting inputs is not allowed */ |
7b8e00d9 KG |
1478 | if (!test_bit(FLAG_IS_OUT, &lr->lines[i].desc->flags)) |
1479 | return -EPERM; | |
193b6b09 | 1480 | /* add to compacted values */ |
32d8e3b6 | 1481 | if (lv.bits & BIT_ULL(i)) |
7b8e00d9 KG |
1482 | __set_bit(num_set, vals); |
1483 | num_set++; | |
193b6b09 | 1484 | /* capture desc for the num_set == 1 case */ |
7b8e00d9 KG |
1485 | descs = &lr->lines[i].desc; |
1486 | } | |
1487 | } | |
1488 | if (num_set == 0) | |
1489 | return -EINVAL; | |
1490 | ||
1491 | if (num_set != 1) { | |
193b6b09 | 1492 | /* build compacted desc array */ |
7b8e00d9 KG |
1493 | descs = kmalloc_array(num_set, sizeof(*descs), GFP_KERNEL); |
1494 | if (!descs) | |
1495 | return -ENOMEM; | |
1496 | for (didx = 0, i = 0; i < lr->num_lines; i++) { | |
32d8e3b6 | 1497 | if (lv.mask & BIT_ULL(i)) { |
7b8e00d9 KG |
1498 | descs[didx] = lr->lines[i].desc; |
1499 | didx++; | |
1500 | } | |
1501 | } | |
1502 | } | |
1503 | ret = gpiod_set_array_value_complex(false, true, num_set, | |
1504 | descs, NULL, vals); | |
1505 | ||
1506 | if (num_set != 1) | |
1507 | kfree(descs); | |
1508 | return ret; | |
1509 | } | |
1510 | ||
32d8e3b6 | 1511 | static long linereq_set_config(struct linereq *lr, void __user *ip) |
a54756cb | 1512 | { |
32d8e3b6 | 1513 | struct gpio_v2_line_config lc; |
a54756cb | 1514 | struct gpio_desc *desc; |
b1a92e94 | 1515 | struct line *line; |
a54756cb | 1516 | unsigned int i; |
b1a92e94 | 1517 | u64 flags, edflags; |
a54756cb KG |
1518 | int ret; |
1519 | ||
32d8e3b6 KG |
1520 | if (copy_from_user(&lc, ip, sizeof(lc))) |
1521 | return -EFAULT; | |
1522 | ||
1523 | ret = gpio_v2_line_config_validate(&lc, lr->num_lines); | |
1524 | if (ret) | |
1525 | return ret; | |
1526 | ||
1527 | guard(mutex)(&lr->config_mutex); | |
1528 | ||
a54756cb | 1529 | for (i = 0; i < lr->num_lines; i++) { |
b1a92e94 | 1530 | line = &lr->lines[i]; |
a54756cb | 1531 | desc = lr->lines[i].desc; |
32d8e3b6 | 1532 | flags = gpio_v2_line_config_flags(&lc, i); |
a54756cb | 1533 | gpio_v2_line_config_flags_to_desc_flags(flags, &desc->flags); |
b1a92e94 | 1534 | edflags = flags & GPIO_V2_LINE_EDGE_DETECTOR_FLAGS; |
925ca369 KG |
1535 | /* |
1536 | * Lines have to be requested explicitly for input | |
1537 | * or output, else the line will be treated "as is". | |
1538 | */ | |
a54756cb | 1539 | if (flags & GPIO_V2_LINE_FLAG_OUTPUT) { |
32d8e3b6 | 1540 | int val = gpio_v2_line_config_output_value(&lc, i); |
925ca369 | 1541 | |
b1a92e94 | 1542 | edge_detector_stop(line); |
925ca369 KG |
1543 | ret = gpiod_direction_output(desc, val); |
1544 | if (ret) | |
1545 | return ret; | |
a54756cb | 1546 | } else if (flags & GPIO_V2_LINE_FLAG_INPUT) { |
925ca369 KG |
1547 | ret = gpiod_direction_input(desc); |
1548 | if (ret) | |
1549 | return ret; | |
a54756cb | 1550 | |
32d8e3b6 | 1551 | ret = edge_detector_update(line, &lc, i, edflags); |
a54756cb KG |
1552 | if (ret) |
1553 | return ret; | |
925ca369 KG |
1554 | } |
1555 | ||
b1a92e94 KG |
1556 | WRITE_ONCE(line->edflags, edflags); |
1557 | ||
9ce4ed5b | 1558 | gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG); |
925ca369 KG |
1559 | } |
1560 | return 0; | |
1561 | } | |
1562 | ||
20bddcb4 KG |
1563 | static long linereq_ioctl(struct file *file, unsigned int cmd, |
1564 | unsigned long arg) | |
3c0d9c63 KG |
1565 | { |
1566 | struct linereq *lr = file->private_data; | |
1567 | void __user *ip = (void __user *)arg; | |
1568 | ||
d83cee3d | 1569 | guard(srcu)(&lr->gdev->srcu); |
20bddcb4 | 1570 | |
8574b5b4 | 1571 | if (!rcu_access_pointer(lr->gdev->chip)) |
533aae7c BG |
1572 | return -ENODEV; |
1573 | ||
1cef8b50 AS |
1574 | switch (cmd) { |
1575 | case GPIO_V2_LINE_GET_VALUES_IOCTL: | |
3c0d9c63 | 1576 | return linereq_get_values(lr, ip); |
1cef8b50 | 1577 | case GPIO_V2_LINE_SET_VALUES_IOCTL: |
7b8e00d9 | 1578 | return linereq_set_values(lr, ip); |
1cef8b50 | 1579 | case GPIO_V2_LINE_SET_CONFIG_IOCTL: |
a54756cb | 1580 | return linereq_set_config(lr, ip); |
1cef8b50 AS |
1581 | default: |
1582 | return -EINVAL; | |
1583 | } | |
925ca369 KG |
1584 | } |
1585 | ||
1586 | #ifdef CONFIG_COMPAT | |
3c0d9c63 KG |
1587 | static long linereq_ioctl_compat(struct file *file, unsigned int cmd, |
1588 | unsigned long arg) | |
925ca369 | 1589 | { |
3c0d9c63 | 1590 | return linereq_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); |
925ca369 KG |
1591 | } |
1592 | #endif | |
1593 | ||
20bddcb4 KG |
1594 | static __poll_t linereq_poll(struct file *file, |
1595 | struct poll_table_struct *wait) | |
925ca369 | 1596 | { |
73e03419 KG |
1597 | struct linereq *lr = file->private_data; |
1598 | __poll_t events = 0; | |
925ca369 | 1599 | |
d83cee3d | 1600 | guard(srcu)(&lr->gdev->srcu); |
20bddcb4 | 1601 | |
8574b5b4 | 1602 | if (!rcu_access_pointer(lr->gdev->chip)) |
533aae7c BG |
1603 | return EPOLLHUP | EPOLLERR; |
1604 | ||
73e03419 KG |
1605 | poll_wait(file, &lr->wait, wait); |
1606 | ||
1607 | if (!kfifo_is_empty_spinlocked_noirqsave(&lr->events, | |
1608 | &lr->wait.lock)) | |
1609 | events = EPOLLIN | EPOLLRDNORM; | |
1610 | ||
1611 | return events; | |
883f9198 KG |
1612 | } |
1613 | ||
20bddcb4 KG |
1614 | static ssize_t linereq_read(struct file *file, char __user *buf, |
1615 | size_t count, loff_t *f_ps) | |
883f9198 | 1616 | { |
73e03419 KG |
1617 | struct linereq *lr = file->private_data; |
1618 | struct gpio_v2_line_event le; | |
1619 | ssize_t bytes_read = 0; | |
1620 | int ret; | |
1621 | ||
d83cee3d | 1622 | guard(srcu)(&lr->gdev->srcu); |
20bddcb4 | 1623 | |
8574b5b4 | 1624 | if (!rcu_access_pointer(lr->gdev->chip)) |
533aae7c BG |
1625 | return -ENODEV; |
1626 | ||
73e03419 KG |
1627 | if (count < sizeof(le)) |
1628 | return -EINVAL; | |
1629 | ||
1630 | do { | |
0ebeaab4 KG |
1631 | scoped_guard(spinlock, &lr->wait.lock) { |
1632 | if (kfifo_is_empty(&lr->events)) { | |
1633 | if (bytes_read) | |
1634 | return bytes_read; | |
1635 | ||
1636 | if (file->f_flags & O_NONBLOCK) | |
1637 | return -EAGAIN; | |
1638 | ||
1639 | ret = wait_event_interruptible_locked(lr->wait, | |
1640 | !kfifo_is_empty(&lr->events)); | |
1641 | if (ret) | |
1642 | return ret; | |
73e03419 KG |
1643 | } |
1644 | ||
0ebeaab4 | 1645 | ret = kfifo_out(&lr->events, &le, 1); |
73e03419 | 1646 | } |
73e03419 KG |
1647 | if (ret != 1) { |
1648 | /* | |
1649 | * This should never happen - we were holding the | |
1650 | * lock from the moment we learned the fifo is no | |
1651 | * longer empty until now. | |
1652 | */ | |
1653 | ret = -EIO; | |
1654 | break; | |
1655 | } | |
1656 | ||
1657 | if (copy_to_user(buf + bytes_read, &le, sizeof(le))) | |
1658 | return -EFAULT; | |
1659 | bytes_read += sizeof(le); | |
1660 | } while (count >= bytes_read + sizeof(le)); | |
1661 | ||
1662 | return bytes_read; | |
1663 | } | |
1664 | ||
3c0d9c63 KG |
1665 | static void linereq_free(struct linereq *lr) |
1666 | { | |
9344e34e | 1667 | struct line *line; |
3c0d9c63 KG |
1668 | unsigned int i; |
1669 | ||
a0dda508 BG |
1670 | if (lr->device_unregistered_nb.notifier_call) |
1671 | blocking_notifier_chain_unregister(&lr->gdev->device_notifier, | |
1672 | &lr->device_unregistered_nb); | |
1673 | ||
3c0d9c63 | 1674 | for (i = 0; i < lr->num_lines; i++) { |
9344e34e KG |
1675 | line = &lr->lines[i]; |
1676 | if (!line->desc) | |
1677 | continue; | |
1678 | ||
1679 | edge_detector_stop(line); | |
1680 | if (line_has_supinfo(line)) | |
1681 | supinfo_erase(line); | |
1682 | gpiod_free(line->desc); | |
3c0d9c63 | 1683 | } |
73e03419 | 1684 | kfifo_free(&lr->events); |
3c0d9c63 | 1685 | kfree(lr->label); |
dc0989e3 | 1686 | gpio_device_put(lr->gdev); |
b718fbfe | 1687 | kvfree(lr); |
3c0d9c63 KG |
1688 | } |
1689 | ||
1690 | static int linereq_release(struct inode *inode, struct file *file) | |
1691 | { | |
1692 | struct linereq *lr = file->private_data; | |
1693 | ||
1694 | linereq_free(lr); | |
925ca369 KG |
1695 | return 0; |
1696 | } | |
1697 | ||
0ae3109a BG |
1698 | #ifdef CONFIG_PROC_FS |
1699 | static void linereq_show_fdinfo(struct seq_file *out, struct file *file) | |
1700 | { | |
1701 | struct linereq *lr = file->private_data; | |
1702 | struct device *dev = &lr->gdev->dev; | |
1703 | u16 i; | |
1704 | ||
1705 | seq_printf(out, "gpio-chip:\t%s\n", dev_name(dev)); | |
1706 | ||
1707 | for (i = 0; i < lr->num_lines; i++) | |
1708 | seq_printf(out, "gpio-line:\t%d\n", | |
1709 | gpio_chip_hwgpio(lr->lines[i].desc)); | |
1710 | } | |
1711 | #endif | |
1712 | ||
3c0d9c63 KG |
1713 | static const struct file_operations line_fileops = { |
1714 | .release = linereq_release, | |
73e03419 KG |
1715 | .read = linereq_read, |
1716 | .poll = linereq_poll, | |
925ca369 KG |
1717 | .owner = THIS_MODULE, |
1718 | .llseek = noop_llseek, | |
3c0d9c63 | 1719 | .unlocked_ioctl = linereq_ioctl, |
925ca369 | 1720 | #ifdef CONFIG_COMPAT |
3c0d9c63 | 1721 | .compat_ioctl = linereq_ioctl_compat, |
925ca369 | 1722 | #endif |
0ae3109a BG |
1723 | #ifdef CONFIG_PROC_FS |
1724 | .show_fdinfo = linereq_show_fdinfo, | |
1725 | #endif | |
925ca369 KG |
1726 | }; |
1727 | ||
3c0d9c63 | 1728 | static int linereq_create(struct gpio_device *gdev, void __user *ip) |
925ca369 | 1729 | { |
3c0d9c63 KG |
1730 | struct gpio_v2_line_request ulr; |
1731 | struct gpio_v2_line_config *lc; | |
1732 | struct linereq *lr; | |
925ca369 | 1733 | struct file *file; |
b1a92e94 | 1734 | u64 flags, edflags; |
3c0d9c63 KG |
1735 | unsigned int i; |
1736 | int fd, ret; | |
925ca369 | 1737 | |
3c0d9c63 | 1738 | if (copy_from_user(&ulr, ip, sizeof(ulr))) |
925ca369 | 1739 | return -EFAULT; |
3c0d9c63 KG |
1740 | |
1741 | if ((ulr.num_lines == 0) || (ulr.num_lines > GPIO_V2_LINES_MAX)) | |
925ca369 KG |
1742 | return -EINVAL; |
1743 | ||
3c0d9c63 KG |
1744 | if (memchr_inv(ulr.padding, 0, sizeof(ulr.padding))) |
1745 | return -EINVAL; | |
925ca369 | 1746 | |
3c0d9c63 KG |
1747 | lc = &ulr.config; |
1748 | ret = gpio_v2_line_config_validate(lc, ulr.num_lines); | |
925ca369 KG |
1749 | if (ret) |
1750 | return ret; | |
1751 | ||
b718fbfe | 1752 | lr = kvzalloc(struct_size(lr, lines, ulr.num_lines), GFP_KERNEL); |
3c0d9c63 | 1753 | if (!lr) |
925ca369 | 1754 | return -ENOMEM; |
a512635d | 1755 | lr->num_lines = ulr.num_lines; |
3c0d9c63 | 1756 | |
dc0989e3 | 1757 | lr->gdev = gpio_device_get(gdev); |
925ca369 | 1758 | |
65cff704 | 1759 | for (i = 0; i < ulr.num_lines; i++) { |
73e03419 | 1760 | lr->lines[i].req = lr; |
65cff704 KG |
1761 | WRITE_ONCE(lr->lines[i].sw_debounced, 0); |
1762 | INIT_DELAYED_WORK(&lr->lines[i].work, debounce_work_func); | |
1763 | } | |
73e03419 | 1764 | |
f188ac12 | 1765 | if (ulr.consumer[0] != '\0') { |
3c0d9c63 | 1766 | /* label is only initialized if consumer is set */ |
f188ac12 KG |
1767 | lr->label = kstrndup(ulr.consumer, sizeof(ulr.consumer) - 1, |
1768 | GFP_KERNEL); | |
3c0d9c63 | 1769 | if (!lr->label) { |
925ca369 | 1770 | ret = -ENOMEM; |
3c0d9c63 | 1771 | goto out_free_linereq; |
925ca369 KG |
1772 | } |
1773 | } | |
1774 | ||
a54756cb | 1775 | mutex_init(&lr->config_mutex); |
73e03419 KG |
1776 | init_waitqueue_head(&lr->wait); |
1777 | lr->event_buffer_size = ulr.event_buffer_size; | |
1778 | if (lr->event_buffer_size == 0) | |
1779 | lr->event_buffer_size = ulr.num_lines * 16; | |
1780 | else if (lr->event_buffer_size > GPIO_V2_LINES_MAX * 16) | |
1781 | lr->event_buffer_size = GPIO_V2_LINES_MAX * 16; | |
1782 | ||
1783 | atomic_set(&lr->seqno, 0); | |
883f9198 | 1784 | |
925ca369 | 1785 | /* Request each GPIO */ |
3c0d9c63 KG |
1786 | for (i = 0; i < ulr.num_lines; i++) { |
1787 | u32 offset = ulr.offsets[i]; | |
f4e14d45 | 1788 | struct gpio_desc *desc = gpio_device_get_desc(gdev, offset); |
925ca369 KG |
1789 | |
1790 | if (IS_ERR(desc)) { | |
1791 | ret = PTR_ERR(desc); | |
3c0d9c63 | 1792 | goto out_free_linereq; |
925ca369 KG |
1793 | } |
1794 | ||
95a4eed7 | 1795 | ret = gpiod_request_user(desc, lr->label); |
925ca369 | 1796 | if (ret) |
3c0d9c63 KG |
1797 | goto out_free_linereq; |
1798 | ||
1799 | lr->lines[i].desc = desc; | |
1800 | flags = gpio_v2_line_config_flags(lc, i); | |
1801 | gpio_v2_line_config_flags_to_desc_flags(flags, &desc->flags); | |
925ca369 KG |
1802 | |
1803 | ret = gpiod_set_transitory(desc, false); | |
1804 | if (ret < 0) | |
3c0d9c63 | 1805 | goto out_free_linereq; |
925ca369 | 1806 | |
b1a92e94 | 1807 | edflags = flags & GPIO_V2_LINE_EDGE_DETECTOR_FLAGS; |
925ca369 KG |
1808 | /* |
1809 | * Lines have to be requested explicitly for input | |
1810 | * or output, else the line will be treated "as is". | |
1811 | */ | |
3c0d9c63 KG |
1812 | if (flags & GPIO_V2_LINE_FLAG_OUTPUT) { |
1813 | int val = gpio_v2_line_config_output_value(lc, i); | |
925ca369 KG |
1814 | |
1815 | ret = gpiod_direction_output(desc, val); | |
1816 | if (ret) | |
3c0d9c63 KG |
1817 | goto out_free_linereq; |
1818 | } else if (flags & GPIO_V2_LINE_FLAG_INPUT) { | |
925ca369 KG |
1819 | ret = gpiod_direction_input(desc); |
1820 | if (ret) | |
3c0d9c63 | 1821 | goto out_free_linereq; |
73e03419 | 1822 | |
65cff704 | 1823 | ret = edge_detector_setup(&lr->lines[i], lc, i, |
b1a92e94 | 1824 | edflags); |
73e03419 KG |
1825 | if (ret) |
1826 | goto out_free_linereq; | |
925ca369 KG |
1827 | } |
1828 | ||
b1a92e94 KG |
1829 | lr->lines[i].edflags = edflags; |
1830 | ||
9ce4ed5b | 1831 | gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_REQUESTED); |
925ca369 KG |
1832 | |
1833 | dev_dbg(&gdev->dev, "registered chardev handle for line %d\n", | |
1834 | offset); | |
1835 | } | |
925ca369 | 1836 | |
a0dda508 BG |
1837 | lr->device_unregistered_nb.notifier_call = linereq_unregistered_notify; |
1838 | ret = blocking_notifier_chain_register(&gdev->device_notifier, | |
1839 | &lr->device_unregistered_nb); | |
1840 | if (ret) | |
1841 | goto out_free_linereq; | |
1842 | ||
925ca369 KG |
1843 | fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC); |
1844 | if (fd < 0) { | |
1845 | ret = fd; | |
3c0d9c63 | 1846 | goto out_free_linereq; |
925ca369 KG |
1847 | } |
1848 | ||
3c0d9c63 | 1849 | file = anon_inode_getfile("gpio-line", &line_fileops, lr, |
925ca369 KG |
1850 | O_RDONLY | O_CLOEXEC); |
1851 | if (IS_ERR(file)) { | |
1852 | ret = PTR_ERR(file); | |
1853 | goto out_put_unused_fd; | |
1854 | } | |
1855 | ||
3c0d9c63 KG |
1856 | ulr.fd = fd; |
1857 | if (copy_to_user(ip, &ulr, sizeof(ulr))) { | |
925ca369 KG |
1858 | /* |
1859 | * fput() will trigger the release() callback, so do not go onto | |
1860 | * the regular error cleanup path here. | |
1861 | */ | |
1862 | fput(file); | |
1863 | put_unused_fd(fd); | |
1864 | return -EFAULT; | |
1865 | } | |
1866 | ||
1867 | fd_install(fd, file); | |
1868 | ||
1869 | dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n", | |
3c0d9c63 | 1870 | lr->num_lines); |
925ca369 KG |
1871 | |
1872 | return 0; | |
1873 | ||
1874 | out_put_unused_fd: | |
1875 | put_unused_fd(fd); | |
3c0d9c63 KG |
1876 | out_free_linereq: |
1877 | linereq_free(lr); | |
925ca369 KG |
1878 | return ret; |
1879 | } | |
1880 | ||
3c0d9c63 | 1881 | #ifdef CONFIG_GPIO_CDEV_V1 |
925ca369 KG |
1882 | |
1883 | /* | |
1884 | * GPIO line event management | |
1885 | */ | |
1886 | ||
1887 | /** | |
1888 | * struct lineevent_state - contains the state of a userspace event | |
1889 | * @gdev: the GPIO device the event pertains to | |
1890 | * @label: consumer label used to tag descriptors | |
1891 | * @desc: the GPIO descriptor held by this event | |
1892 | * @eflags: the event flags this line was requested with | |
1893 | * @irq: the interrupt that trigger in response to events on this GPIO | |
1894 | * @wait: wait queue that handles blocking reads of events | |
91043f55 | 1895 | * @device_unregistered_nb: notifier block for receiving gdev unregister events |
925ca369 KG |
1896 | * @events: KFIFO for the GPIO events |
1897 | * @timestamp: cache for the timestamp storing it between hardirq | |
1898 | * and IRQ thread, used to bring the timestamp close to the actual | |
1899 | * event | |
1900 | */ | |
1901 | struct lineevent_state { | |
1902 | struct gpio_device *gdev; | |
1903 | const char *label; | |
1904 | struct gpio_desc *desc; | |
1905 | u32 eflags; | |
1906 | int irq; | |
1907 | wait_queue_head_t wait; | |
91043f55 | 1908 | struct notifier_block device_unregistered_nb; |
925ca369 KG |
1909 | DECLARE_KFIFO(events, struct gpioevent_data, 16); |
1910 | u64 timestamp; | |
1911 | }; | |
1912 | ||
1913 | #define GPIOEVENT_REQUEST_VALID_FLAGS \ | |
1914 | (GPIOEVENT_REQUEST_RISING_EDGE | \ | |
1915 | GPIOEVENT_REQUEST_FALLING_EDGE) | |
1916 | ||
20bddcb4 KG |
1917 | static __poll_t lineevent_poll(struct file *file, |
1918 | struct poll_table_struct *wait) | |
925ca369 | 1919 | { |
49bc5279 | 1920 | struct lineevent_state *le = file->private_data; |
925ca369 KG |
1921 | __poll_t events = 0; |
1922 | ||
d83cee3d | 1923 | guard(srcu)(&le->gdev->srcu); |
20bddcb4 | 1924 | |
8574b5b4 | 1925 | if (!rcu_access_pointer(le->gdev->chip)) |
533aae7c BG |
1926 | return EPOLLHUP | EPOLLERR; |
1927 | ||
49bc5279 | 1928 | poll_wait(file, &le->wait, wait); |
925ca369 KG |
1929 | |
1930 | if (!kfifo_is_empty_spinlocked_noirqsave(&le->events, &le->wait.lock)) | |
1931 | events = EPOLLIN | EPOLLRDNORM; | |
1932 | ||
1933 | return events; | |
1934 | } | |
1935 | ||
91043f55 BG |
1936 | static int lineevent_unregistered_notify(struct notifier_block *nb, |
1937 | unsigned long action, void *data) | |
1938 | { | |
1939 | struct lineevent_state *le = container_of(nb, struct lineevent_state, | |
1940 | device_unregistered_nb); | |
1941 | ||
1942 | wake_up_poll(&le->wait, EPOLLIN | EPOLLERR); | |
1943 | ||
1944 | return NOTIFY_OK; | |
1945 | } | |
1946 | ||
163d1719 AS |
1947 | struct compat_gpioeevent_data { |
1948 | compat_u64 timestamp; | |
1949 | u32 id; | |
1950 | }; | |
925ca369 | 1951 | |
20bddcb4 KG |
1952 | static ssize_t lineevent_read(struct file *file, char __user *buf, |
1953 | size_t count, loff_t *f_ps) | |
925ca369 | 1954 | { |
49bc5279 | 1955 | struct lineevent_state *le = file->private_data; |
925ca369 KG |
1956 | struct gpioevent_data ge; |
1957 | ssize_t bytes_read = 0; | |
5ad284ab | 1958 | ssize_t ge_size; |
925ca369 KG |
1959 | int ret; |
1960 | ||
d83cee3d | 1961 | guard(srcu)(&le->gdev->srcu); |
20bddcb4 | 1962 | |
8574b5b4 | 1963 | if (!rcu_access_pointer(le->gdev->chip)) |
533aae7c BG |
1964 | return -ENODEV; |
1965 | ||
5ad284ab AS |
1966 | /* |
1967 | * When compatible system call is being used the struct gpioevent_data, | |
1968 | * in case of at least ia32, has different size due to the alignment | |
1969 | * differences. Because we have first member 64 bits followed by one of | |
1970 | * 32 bits there is no gap between them. The only difference is the | |
1971 | * padding at the end of the data structure. Hence, we calculate the | |
1972 | * actual sizeof() and pass this as an argument to copy_to_user() to | |
1973 | * drop unneeded bytes from the output. | |
1974 | */ | |
163d1719 AS |
1975 | if (compat_need_64bit_alignment_fixup()) |
1976 | ge_size = sizeof(struct compat_gpioeevent_data); | |
1977 | else | |
1978 | ge_size = sizeof(struct gpioevent_data); | |
5ad284ab | 1979 | if (count < ge_size) |
925ca369 KG |
1980 | return -EINVAL; |
1981 | ||
1982 | do { | |
0ebeaab4 KG |
1983 | scoped_guard(spinlock, &le->wait.lock) { |
1984 | if (kfifo_is_empty(&le->events)) { | |
1985 | if (bytes_read) | |
1986 | return bytes_read; | |
1987 | ||
1988 | if (file->f_flags & O_NONBLOCK) | |
1989 | return -EAGAIN; | |
1990 | ||
1991 | ret = wait_event_interruptible_locked(le->wait, | |
1992 | !kfifo_is_empty(&le->events)); | |
1993 | if (ret) | |
1994 | return ret; | |
925ca369 KG |
1995 | } |
1996 | ||
0ebeaab4 | 1997 | ret = kfifo_out(&le->events, &ge, 1); |
925ca369 | 1998 | } |
925ca369 KG |
1999 | if (ret != 1) { |
2000 | /* | |
2001 | * This should never happen - we were holding the lock | |
2002 | * from the moment we learned the fifo is no longer | |
2003 | * empty until now. | |
2004 | */ | |
2005 | ret = -EIO; | |
2006 | break; | |
2007 | } | |
2008 | ||
5ad284ab | 2009 | if (copy_to_user(buf + bytes_read, &ge, ge_size)) |
925ca369 | 2010 | return -EFAULT; |
5ad284ab AS |
2011 | bytes_read += ge_size; |
2012 | } while (count >= bytes_read + ge_size); | |
925ca369 KG |
2013 | |
2014 | return bytes_read; | |
2015 | } | |
2016 | ||
46824272 | 2017 | static void lineevent_free(struct lineevent_state *le) |
925ca369 | 2018 | { |
91043f55 BG |
2019 | if (le->device_unregistered_nb.notifier_call) |
2020 | blocking_notifier_chain_unregister(&le->gdev->device_notifier, | |
2021 | &le->device_unregistered_nb); | |
46824272 | 2022 | if (le->irq) |
b3449087 | 2023 | free_irq_label(free_irq(le->irq, le)); |
46824272 KG |
2024 | if (le->desc) |
2025 | gpiod_free(le->desc); | |
925ca369 | 2026 | kfree(le->label); |
dc0989e3 | 2027 | gpio_device_put(le->gdev); |
925ca369 | 2028 | kfree(le); |
46824272 KG |
2029 | } |
2030 | ||
2031 | static int lineevent_release(struct inode *inode, struct file *file) | |
2032 | { | |
2033 | lineevent_free(file->private_data); | |
925ca369 KG |
2034 | return 0; |
2035 | } | |
2036 | ||
20bddcb4 KG |
2037 | static long lineevent_ioctl(struct file *file, unsigned int cmd, |
2038 | unsigned long arg) | |
925ca369 | 2039 | { |
49bc5279 | 2040 | struct lineevent_state *le = file->private_data; |
925ca369 KG |
2041 | void __user *ip = (void __user *)arg; |
2042 | struct gpiohandle_data ghd; | |
2043 | ||
d83cee3d | 2044 | guard(srcu)(&le->gdev->srcu); |
20bddcb4 | 2045 | |
8574b5b4 | 2046 | if (!rcu_access_pointer(le->gdev->chip)) |
533aae7c BG |
2047 | return -ENODEV; |
2048 | ||
925ca369 KG |
2049 | /* |
2050 | * We can get the value for an event line but not set it, | |
2051 | * because it is input by definition. | |
2052 | */ | |
2053 | if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) { | |
2054 | int val; | |
2055 | ||
2056 | memset(&ghd, 0, sizeof(ghd)); | |
2057 | ||
2058 | val = gpiod_get_value_cansleep(le->desc); | |
2059 | if (val < 0) | |
2060 | return val; | |
2061 | ghd.values[0] = val; | |
2062 | ||
2063 | if (copy_to_user(ip, &ghd, sizeof(ghd))) | |
2064 | return -EFAULT; | |
2065 | ||
2066 | return 0; | |
2067 | } | |
2068 | return -EINVAL; | |
2069 | } | |
2070 | ||
2071 | #ifdef CONFIG_COMPAT | |
49bc5279 | 2072 | static long lineevent_ioctl_compat(struct file *file, unsigned int cmd, |
925ca369 KG |
2073 | unsigned long arg) |
2074 | { | |
49bc5279 | 2075 | return lineevent_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); |
925ca369 KG |
2076 | } |
2077 | #endif | |
2078 | ||
2079 | static const struct file_operations lineevent_fileops = { | |
2080 | .release = lineevent_release, | |
2081 | .read = lineevent_read, | |
2082 | .poll = lineevent_poll, | |
2083 | .owner = THIS_MODULE, | |
2084 | .llseek = noop_llseek, | |
2085 | .unlocked_ioctl = lineevent_ioctl, | |
2086 | #ifdef CONFIG_COMPAT | |
2087 | .compat_ioctl = lineevent_ioctl_compat, | |
2088 | #endif | |
2089 | }; | |
2090 | ||
2091 | static irqreturn_t lineevent_irq_thread(int irq, void *p) | |
2092 | { | |
2093 | struct lineevent_state *le = p; | |
2094 | struct gpioevent_data ge; | |
2095 | int ret; | |
2096 | ||
2097 | /* Do not leak kernel stack to userspace */ | |
2098 | memset(&ge, 0, sizeof(ge)); | |
2099 | ||
2100 | /* | |
2101 | * We may be running from a nested threaded interrupt in which case | |
2102 | * we didn't get the timestamp from lineevent_irq_handler(). | |
2103 | */ | |
2104 | if (!le->timestamp) | |
2105 | ge.timestamp = ktime_get_ns(); | |
2106 | else | |
2107 | ge.timestamp = le->timestamp; | |
2108 | ||
2109 | if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE | |
2110 | && le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) { | |
2111 | int level = gpiod_get_value_cansleep(le->desc); | |
2112 | ||
2113 | if (level) | |
2114 | /* Emit low-to-high event */ | |
2115 | ge.id = GPIOEVENT_EVENT_RISING_EDGE; | |
2116 | else | |
2117 | /* Emit high-to-low event */ | |
2118 | ge.id = GPIOEVENT_EVENT_FALLING_EDGE; | |
2119 | } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE) { | |
2120 | /* Emit low-to-high event */ | |
2121 | ge.id = GPIOEVENT_EVENT_RISING_EDGE; | |
2122 | } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) { | |
2123 | /* Emit high-to-low event */ | |
2124 | ge.id = GPIOEVENT_EVENT_FALLING_EDGE; | |
2125 | } else { | |
2126 | return IRQ_NONE; | |
2127 | } | |
2128 | ||
2129 | ret = kfifo_in_spinlocked_noirqsave(&le->events, &ge, | |
2130 | 1, &le->wait.lock); | |
2131 | if (ret) | |
2132 | wake_up_poll(&le->wait, EPOLLIN); | |
2133 | else | |
2134 | pr_debug_ratelimited("event FIFO is full - event dropped\n"); | |
2135 | ||
2136 | return IRQ_HANDLED; | |
2137 | } | |
2138 | ||
2139 | static irqreturn_t lineevent_irq_handler(int irq, void *p) | |
2140 | { | |
2141 | struct lineevent_state *le = p; | |
2142 | ||
2143 | /* | |
2144 | * Just store the timestamp in hardirq context so we get it as | |
2145 | * close in time as possible to the actual event. | |
2146 | */ | |
2147 | le->timestamp = ktime_get_ns(); | |
2148 | ||
2149 | return IRQ_WAKE_THREAD; | |
2150 | } | |
2151 | ||
2152 | static int lineevent_create(struct gpio_device *gdev, void __user *ip) | |
2153 | { | |
2154 | struct gpioevent_request eventreq; | |
2155 | struct lineevent_state *le; | |
2156 | struct gpio_desc *desc; | |
2157 | struct file *file; | |
2158 | u32 offset; | |
2159 | u32 lflags; | |
2160 | u32 eflags; | |
2161 | int fd; | |
2162 | int ret; | |
46824272 | 2163 | int irq, irqflags = 0; |
b3449087 | 2164 | char *label; |
925ca369 KG |
2165 | |
2166 | if (copy_from_user(&eventreq, ip, sizeof(eventreq))) | |
2167 | return -EFAULT; | |
2168 | ||
2169 | offset = eventreq.lineoffset; | |
2170 | lflags = eventreq.handleflags; | |
2171 | eflags = eventreq.eventflags; | |
2172 | ||
f4e14d45 | 2173 | desc = gpio_device_get_desc(gdev, offset); |
925ca369 KG |
2174 | if (IS_ERR(desc)) |
2175 | return PTR_ERR(desc); | |
2176 | ||
2177 | /* Return an error if a unknown flag is set */ | |
2178 | if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) || | |
2179 | (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) | |
2180 | return -EINVAL; | |
2181 | ||
2182 | /* This is just wrong: we don't look for events on output lines */ | |
2183 | if ((lflags & GPIOHANDLE_REQUEST_OUTPUT) || | |
2184 | (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) || | |
2185 | (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) | |
2186 | return -EINVAL; | |
2187 | ||
2188 | /* Only one bias flag can be set. */ | |
2189 | if (((lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE) && | |
2190 | (lflags & (GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | | |
2191 | GPIOHANDLE_REQUEST_BIAS_PULL_UP))) || | |
2192 | ((lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) && | |
2193 | (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP))) | |
2194 | return -EINVAL; | |
2195 | ||
2196 | le = kzalloc(sizeof(*le), GFP_KERNEL); | |
2197 | if (!le) | |
2198 | return -ENOMEM; | |
dc0989e3 | 2199 | le->gdev = gpio_device_get(gdev); |
925ca369 | 2200 | |
f188ac12 KG |
2201 | if (eventreq.consumer_label[0] != '\0') { |
2202 | /* label is only initialized if consumer_label is set */ | |
2203 | le->label = kstrndup(eventreq.consumer_label, | |
2204 | sizeof(eventreq.consumer_label) - 1, | |
2205 | GFP_KERNEL); | |
925ca369 KG |
2206 | if (!le->label) { |
2207 | ret = -ENOMEM; | |
2208 | goto out_free_le; | |
2209 | } | |
2210 | } | |
2211 | ||
95a4eed7 | 2212 | ret = gpiod_request_user(desc, le->label); |
925ca369 | 2213 | if (ret) |
46824272 | 2214 | goto out_free_le; |
925ca369 KG |
2215 | le->desc = desc; |
2216 | le->eflags = eflags; | |
2217 | ||
c274b58a | 2218 | linehandle_flags_to_desc_flags(lflags, &desc->flags); |
925ca369 KG |
2219 | |
2220 | ret = gpiod_direction_input(desc); | |
2221 | if (ret) | |
46824272 | 2222 | goto out_free_le; |
925ca369 | 2223 | |
9ce4ed5b | 2224 | gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_REQUESTED); |
925ca369 | 2225 | |
46824272 KG |
2226 | irq = gpiod_to_irq(desc); |
2227 | if (irq <= 0) { | |
925ca369 | 2228 | ret = -ENODEV; |
46824272 | 2229 | goto out_free_le; |
925ca369 KG |
2230 | } |
2231 | ||
2232 | if (eflags & GPIOEVENT_REQUEST_RISING_EDGE) | |
2233 | irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? | |
2234 | IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; | |
2235 | if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE) | |
2236 | irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? | |
2237 | IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING; | |
2238 | irqflags |= IRQF_ONESHOT; | |
2239 | ||
2240 | INIT_KFIFO(le->events); | |
2241 | init_waitqueue_head(&le->wait); | |
2242 | ||
91043f55 BG |
2243 | le->device_unregistered_nb.notifier_call = lineevent_unregistered_notify; |
2244 | ret = blocking_notifier_chain_register(&gdev->device_notifier, | |
2245 | &le->device_unregistered_nb); | |
2246 | if (ret) | |
2247 | goto out_free_le; | |
2248 | ||
b3449087 | 2249 | label = make_irq_label(le->label); |
b3b95964 BG |
2250 | if (IS_ERR(label)) { |
2251 | ret = PTR_ERR(label); | |
b3449087 BG |
2252 | goto out_free_le; |
2253 | } | |
2254 | ||
925ca369 | 2255 | /* Request a thread to read the events */ |
69bef19d | 2256 | ret = request_threaded_irq(irq, |
a18512e3 KG |
2257 | lineevent_irq_handler, |
2258 | lineevent_irq_thread, | |
2259 | irqflags, | |
b3449087 | 2260 | label, |
a18512e3 | 2261 | le); |
b3449087 BG |
2262 | if (ret) { |
2263 | free_irq_label(label); | |
46824272 | 2264 | goto out_free_le; |
b3449087 | 2265 | } |
925ca369 | 2266 | |
69bef19d ML |
2267 | le->irq = irq; |
2268 | ||
925ca369 KG |
2269 | fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC); |
2270 | if (fd < 0) { | |
2271 | ret = fd; | |
46824272 | 2272 | goto out_free_le; |
925ca369 KG |
2273 | } |
2274 | ||
2275 | file = anon_inode_getfile("gpio-event", | |
2276 | &lineevent_fileops, | |
2277 | le, | |
2278 | O_RDONLY | O_CLOEXEC); | |
2279 | if (IS_ERR(file)) { | |
2280 | ret = PTR_ERR(file); | |
2281 | goto out_put_unused_fd; | |
2282 | } | |
2283 | ||
2284 | eventreq.fd = fd; | |
2285 | if (copy_to_user(ip, &eventreq, sizeof(eventreq))) { | |
2286 | /* | |
2287 | * fput() will trigger the release() callback, so do not go onto | |
2288 | * the regular error cleanup path here. | |
2289 | */ | |
2290 | fput(file); | |
2291 | put_unused_fd(fd); | |
2292 | return -EFAULT; | |
2293 | } | |
2294 | ||
2295 | fd_install(fd, file); | |
2296 | ||
2297 | return 0; | |
2298 | ||
2299 | out_put_unused_fd: | |
2300 | put_unused_fd(fd); | |
925ca369 | 2301 | out_free_le: |
46824272 | 2302 | lineevent_free(le); |
925ca369 KG |
2303 | return ret; |
2304 | } | |
2305 | ||
aad95584 KG |
2306 | static void gpio_v2_line_info_to_v1(struct gpio_v2_line_info *info_v2, |
2307 | struct gpioline_info *info_v1) | |
2308 | { | |
2309 | u64 flagsv2 = info_v2->flags; | |
2310 | ||
2311 | memcpy(info_v1->name, info_v2->name, sizeof(info_v1->name)); | |
2312 | memcpy(info_v1->consumer, info_v2->consumer, sizeof(info_v1->consumer)); | |
2313 | info_v1->line_offset = info_v2->offset; | |
2314 | info_v1->flags = 0; | |
2315 | ||
2316 | if (flagsv2 & GPIO_V2_LINE_FLAG_USED) | |
2317 | info_v1->flags |= GPIOLINE_FLAG_KERNEL; | |
2318 | ||
2319 | if (flagsv2 & GPIO_V2_LINE_FLAG_OUTPUT) | |
2320 | info_v1->flags |= GPIOLINE_FLAG_IS_OUT; | |
2321 | ||
2322 | if (flagsv2 & GPIO_V2_LINE_FLAG_ACTIVE_LOW) | |
2323 | info_v1->flags |= GPIOLINE_FLAG_ACTIVE_LOW; | |
2324 | ||
2325 | if (flagsv2 & GPIO_V2_LINE_FLAG_OPEN_DRAIN) | |
2326 | info_v1->flags |= GPIOLINE_FLAG_OPEN_DRAIN; | |
2327 | if (flagsv2 & GPIO_V2_LINE_FLAG_OPEN_SOURCE) | |
2328 | info_v1->flags |= GPIOLINE_FLAG_OPEN_SOURCE; | |
2329 | ||
2330 | if (flagsv2 & GPIO_V2_LINE_FLAG_BIAS_PULL_UP) | |
2331 | info_v1->flags |= GPIOLINE_FLAG_BIAS_PULL_UP; | |
2332 | if (flagsv2 & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN) | |
2333 | info_v1->flags |= GPIOLINE_FLAG_BIAS_PULL_DOWN; | |
2334 | if (flagsv2 & GPIO_V2_LINE_FLAG_BIAS_DISABLED) | |
2335 | info_v1->flags |= GPIOLINE_FLAG_BIAS_DISABLE; | |
2336 | } | |
2337 | ||
2338 | static void gpio_v2_line_info_changed_to_v1( | |
2339 | struct gpio_v2_line_info_changed *lic_v2, | |
2340 | struct gpioline_info_changed *lic_v1) | |
2341 | { | |
cb8f63b8 | 2342 | memset(lic_v1, 0, sizeof(*lic_v1)); |
aad95584 KG |
2343 | gpio_v2_line_info_to_v1(&lic_v2->info, &lic_v1->info); |
2344 | lic_v1->timestamp = lic_v2->timestamp_ns; | |
2345 | lic_v1->event_type = lic_v2->event_type; | |
2346 | } | |
2347 | ||
3c0d9c63 KG |
2348 | #endif /* CONFIG_GPIO_CDEV_V1 */ |
2349 | ||
925ca369 | 2350 | static void gpio_desc_to_lineinfo(struct gpio_desc *desc, |
aad95584 | 2351 | struct gpio_v2_line_info *info) |
925ca369 | 2352 | { |
1cdc605c | 2353 | unsigned long dflags; |
1f2bcb8c | 2354 | const char *label; |
925ca369 | 2355 | |
d83cee3d BG |
2356 | CLASS(gpio_chip_guard, guard)(desc); |
2357 | if (!guard.gc) | |
2358 | return; | |
2359 | ||
69e4e136 | 2360 | memset(info, 0, sizeof(*info)); |
aad95584 | 2361 | info->offset = gpio_chip_hwgpio(desc); |
925ca369 | 2362 | |
35b54533 BG |
2363 | if (desc->name) |
2364 | strscpy(info->name, desc->name, sizeof(info->name)); | |
2365 | ||
2366 | dflags = READ_ONCE(desc->flags); | |
925ca369 | 2367 | |
7765ffed | 2368 | scoped_guard(srcu, &desc->gdev->desc_srcu) { |
35b54533 BG |
2369 | label = gpiod_get_label(desc); |
2370 | if (label && test_bit(FLAG_REQUESTED, &dflags)) | |
2371 | strscpy(info->consumer, label, | |
2372 | sizeof(info->consumer)); | |
1cdc605c | 2373 | } |
925ca369 KG |
2374 | |
2375 | /* | |
1cdc605c KG |
2376 | * Userspace only need know that the kernel is using this GPIO so it |
2377 | * can't use it. | |
2378 | * The calculation of the used flag is slightly racy, as it may read | |
2379 | * desc, gc and pinctrl state without a lock covering all three at | |
2380 | * once. Worst case if the line is in transition and the calculation | |
2381 | * is inconsistent then it looks to the user like they performed the | |
2382 | * read on the other side of the transition - but that can always | |
2383 | * happen. | |
2384 | * The definitive test that a line is available to userspace is to | |
2385 | * request it. | |
925ca369 | 2386 | */ |
1cdc605c KG |
2387 | if (test_bit(FLAG_REQUESTED, &dflags) || |
2388 | test_bit(FLAG_IS_HOGGED, &dflags) || | |
2389 | test_bit(FLAG_USED_AS_IRQ, &dflags) || | |
2390 | test_bit(FLAG_EXPORT, &dflags) || | |
2391 | test_bit(FLAG_SYSFS, &dflags) || | |
d83cee3d BG |
2392 | !gpiochip_line_is_valid(guard.gc, info->offset) || |
2393 | !pinctrl_gpio_can_use_line(guard.gc, info->offset)) | |
aad95584 KG |
2394 | info->flags |= GPIO_V2_LINE_FLAG_USED; |
2395 | ||
1cdc605c | 2396 | if (test_bit(FLAG_IS_OUT, &dflags)) |
aad95584 KG |
2397 | info->flags |= GPIO_V2_LINE_FLAG_OUTPUT; |
2398 | else | |
2399 | info->flags |= GPIO_V2_LINE_FLAG_INPUT; | |
2400 | ||
1cdc605c | 2401 | if (test_bit(FLAG_ACTIVE_LOW, &dflags)) |
aad95584 KG |
2402 | info->flags |= GPIO_V2_LINE_FLAG_ACTIVE_LOW; |
2403 | ||
1cdc605c | 2404 | if (test_bit(FLAG_OPEN_DRAIN, &dflags)) |
aad95584 | 2405 | info->flags |= GPIO_V2_LINE_FLAG_OPEN_DRAIN; |
1cdc605c | 2406 | if (test_bit(FLAG_OPEN_SOURCE, &dflags)) |
aad95584 KG |
2407 | info->flags |= GPIO_V2_LINE_FLAG_OPEN_SOURCE; |
2408 | ||
1cdc605c | 2409 | if (test_bit(FLAG_BIAS_DISABLE, &dflags)) |
aad95584 | 2410 | info->flags |= GPIO_V2_LINE_FLAG_BIAS_DISABLED; |
1cdc605c | 2411 | if (test_bit(FLAG_PULL_DOWN, &dflags)) |
aad95584 | 2412 | info->flags |= GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN; |
1cdc605c | 2413 | if (test_bit(FLAG_PULL_UP, &dflags)) |
aad95584 | 2414 | info->flags |= GPIO_V2_LINE_FLAG_BIAS_PULL_UP; |
925ca369 | 2415 | |
1cdc605c | 2416 | if (test_bit(FLAG_EDGE_RISING, &dflags)) |
73e03419 | 2417 | info->flags |= GPIO_V2_LINE_FLAG_EDGE_RISING; |
1cdc605c | 2418 | if (test_bit(FLAG_EDGE_FALLING, &dflags)) |
73e03419 KG |
2419 | info->flags |= GPIO_V2_LINE_FLAG_EDGE_FALLING; |
2420 | ||
1cdc605c | 2421 | if (test_bit(FLAG_EVENT_CLOCK_REALTIME, &dflags)) |
26d060e4 | 2422 | info->flags |= GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME; |
1cdc605c | 2423 | else if (test_bit(FLAG_EVENT_CLOCK_HTE, &dflags)) |
2068339a | 2424 | info->flags |= GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE; |
925ca369 KG |
2425 | } |
2426 | ||
2427 | struct gpio_chardev_data { | |
2428 | struct gpio_device *gdev; | |
2429 | wait_queue_head_t wait; | |
aad95584 | 2430 | DECLARE_KFIFO(events, struct gpio_v2_line_info_changed, 32); |
925ca369 | 2431 | struct notifier_block lineinfo_changed_nb; |
d2e2586a | 2432 | struct notifier_block device_unregistered_nb; |
925ca369 | 2433 | unsigned long *watched_lines; |
aad95584 KG |
2434 | #ifdef CONFIG_GPIO_CDEV_V1 |
2435 | atomic_t watch_abi_version; | |
2436 | #endif | |
925ca369 KG |
2437 | }; |
2438 | ||
2e202ad8 KG |
2439 | static int chipinfo_get(struct gpio_chardev_data *cdev, void __user *ip) |
2440 | { | |
2441 | struct gpio_device *gdev = cdev->gdev; | |
2442 | struct gpiochip_info chipinfo; | |
2443 | ||
2444 | memset(&chipinfo, 0, sizeof(chipinfo)); | |
2445 | ||
2446 | strscpy(chipinfo.name, dev_name(&gdev->dev), sizeof(chipinfo.name)); | |
2447 | strscpy(chipinfo.label, gdev->label, sizeof(chipinfo.label)); | |
2448 | chipinfo.lines = gdev->ngpio; | |
2449 | if (copy_to_user(ip, &chipinfo, sizeof(chipinfo))) | |
2450 | return -EFAULT; | |
2451 | return 0; | |
2452 | } | |
2453 | ||
aad95584 KG |
2454 | #ifdef CONFIG_GPIO_CDEV_V1 |
2455 | /* | |
2456 | * returns 0 if the versions match, else the previously selected ABI version | |
2457 | */ | |
2458 | static int lineinfo_ensure_abi_version(struct gpio_chardev_data *cdata, | |
2459 | unsigned int version) | |
2460 | { | |
2461 | int abiv = atomic_cmpxchg(&cdata->watch_abi_version, 0, version); | |
2462 | ||
2463 | if (abiv == version) | |
2464 | return 0; | |
2465 | ||
2466 | return abiv; | |
2467 | } | |
2e202ad8 KG |
2468 | |
2469 | static int lineinfo_get_v1(struct gpio_chardev_data *cdev, void __user *ip, | |
2470 | bool watch) | |
2471 | { | |
2472 | struct gpio_desc *desc; | |
2473 | struct gpioline_info lineinfo; | |
2474 | struct gpio_v2_line_info lineinfo_v2; | |
2475 | ||
2476 | if (copy_from_user(&lineinfo, ip, sizeof(lineinfo))) | |
2477 | return -EFAULT; | |
2478 | ||
2479 | /* this doubles as a range check on line_offset */ | |
f4e14d45 | 2480 | desc = gpio_device_get_desc(cdev->gdev, lineinfo.line_offset); |
2e202ad8 KG |
2481 | if (IS_ERR(desc)) |
2482 | return PTR_ERR(desc); | |
2483 | ||
2484 | if (watch) { | |
2485 | if (lineinfo_ensure_abi_version(cdev, 1)) | |
2486 | return -EPERM; | |
2487 | ||
2488 | if (test_and_set_bit(lineinfo.line_offset, cdev->watched_lines)) | |
2489 | return -EBUSY; | |
2490 | } | |
2491 | ||
2492 | gpio_desc_to_lineinfo(desc, &lineinfo_v2); | |
2493 | gpio_v2_line_info_to_v1(&lineinfo_v2, &lineinfo); | |
2494 | ||
2495 | if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) { | |
2496 | if (watch) | |
2497 | clear_bit(lineinfo.line_offset, cdev->watched_lines); | |
2498 | return -EFAULT; | |
2499 | } | |
2500 | ||
2501 | return 0; | |
2502 | } | |
aad95584 KG |
2503 | #endif |
2504 | ||
2505 | static int lineinfo_get(struct gpio_chardev_data *cdev, void __user *ip, | |
2506 | bool watch) | |
2507 | { | |
2508 | struct gpio_desc *desc; | |
2509 | struct gpio_v2_line_info lineinfo; | |
2510 | ||
2511 | if (copy_from_user(&lineinfo, ip, sizeof(lineinfo))) | |
2512 | return -EFAULT; | |
2513 | ||
2514 | if (memchr_inv(lineinfo.padding, 0, sizeof(lineinfo.padding))) | |
2515 | return -EINVAL; | |
2516 | ||
f4e14d45 | 2517 | desc = gpio_device_get_desc(cdev->gdev, lineinfo.offset); |
aad95584 KG |
2518 | if (IS_ERR(desc)) |
2519 | return PTR_ERR(desc); | |
2520 | ||
2521 | if (watch) { | |
2522 | #ifdef CONFIG_GPIO_CDEV_V1 | |
2523 | if (lineinfo_ensure_abi_version(cdev, 2)) | |
2524 | return -EPERM; | |
2525 | #endif | |
2526 | if (test_and_set_bit(lineinfo.offset, cdev->watched_lines)) | |
2527 | return -EBUSY; | |
2528 | } | |
2529 | gpio_desc_to_lineinfo(desc, &lineinfo); | |
9344e34e | 2530 | supinfo_to_lineinfo(desc, &lineinfo); |
aad95584 KG |
2531 | |
2532 | if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) { | |
2533 | if (watch) | |
2534 | clear_bit(lineinfo.offset, cdev->watched_lines); | |
2535 | return -EFAULT; | |
2536 | } | |
2537 | ||
2538 | return 0; | |
2539 | } | |
2540 | ||
2e202ad8 KG |
2541 | static int lineinfo_unwatch(struct gpio_chardev_data *cdev, void __user *ip) |
2542 | { | |
2543 | __u32 offset; | |
2544 | ||
2545 | if (copy_from_user(&offset, ip, sizeof(offset))) | |
2546 | return -EFAULT; | |
2547 | ||
2548 | if (offset >= cdev->gdev->ngpio) | |
2549 | return -EINVAL; | |
2550 | ||
2551 | if (!test_and_clear_bit(offset, cdev->watched_lines)) | |
2552 | return -EBUSY; | |
2553 | ||
2554 | return 0; | |
2555 | } | |
2556 | ||
20bddcb4 KG |
2557 | /* |
2558 | * gpio_ioctl() - ioctl handler for the GPIO chardev | |
2559 | */ | |
2560 | static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
925ca369 | 2561 | { |
e2b781c5 KG |
2562 | struct gpio_chardev_data *cdev = file->private_data; |
2563 | struct gpio_device *gdev = cdev->gdev; | |
925ca369 | 2564 | void __user *ip = (void __user *)arg; |
925ca369 | 2565 | |
d83cee3d | 2566 | guard(srcu)(&gdev->srcu); |
20bddcb4 | 2567 | |
925ca369 | 2568 | /* We fail any subsequent ioctl():s when the chip is gone */ |
8574b5b4 | 2569 | if (!rcu_access_pointer(gdev->chip)) |
925ca369 KG |
2570 | return -ENODEV; |
2571 | ||
2572 | /* Fill in the struct and pass to userspace */ | |
1cef8b50 AS |
2573 | switch (cmd) { |
2574 | case GPIO_GET_CHIPINFO_IOCTL: | |
2e202ad8 | 2575 | return chipinfo_get(cdev, ip); |
3c0d9c63 | 2576 | #ifdef CONFIG_GPIO_CDEV_V1 |
1cef8b50 | 2577 | case GPIO_GET_LINEHANDLE_IOCTL: |
925ca369 | 2578 | return linehandle_create(gdev, ip); |
1cef8b50 | 2579 | case GPIO_GET_LINEEVENT_IOCTL: |
925ca369 | 2580 | return lineevent_create(gdev, ip); |
1cef8b50 AS |
2581 | case GPIO_GET_LINEINFO_IOCTL: |
2582 | return lineinfo_get_v1(cdev, ip, false); | |
2583 | case GPIO_GET_LINEINFO_WATCH_IOCTL: | |
2584 | return lineinfo_get_v1(cdev, ip, true); | |
3c0d9c63 | 2585 | #endif /* CONFIG_GPIO_CDEV_V1 */ |
1cef8b50 AS |
2586 | case GPIO_V2_GET_LINEINFO_IOCTL: |
2587 | return lineinfo_get(cdev, ip, false); | |
2588 | case GPIO_V2_GET_LINEINFO_WATCH_IOCTL: | |
2589 | return lineinfo_get(cdev, ip, true); | |
2590 | case GPIO_V2_GET_LINE_IOCTL: | |
3c0d9c63 | 2591 | return linereq_create(gdev, ip); |
1cef8b50 | 2592 | case GPIO_GET_LINEINFO_UNWATCH_IOCTL: |
2e202ad8 | 2593 | return lineinfo_unwatch(cdev, ip); |
1cef8b50 AS |
2594 | default: |
2595 | return -EINVAL; | |
925ca369 | 2596 | } |
925ca369 KG |
2597 | } |
2598 | ||
2599 | #ifdef CONFIG_COMPAT | |
49bc5279 | 2600 | static long gpio_ioctl_compat(struct file *file, unsigned int cmd, |
925ca369 KG |
2601 | unsigned long arg) |
2602 | { | |
49bc5279 | 2603 | return gpio_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); |
925ca369 KG |
2604 | } |
2605 | #endif | |
2606 | ||
925ca369 KG |
2607 | static int lineinfo_changed_notify(struct notifier_block *nb, |
2608 | unsigned long action, void *data) | |
2609 | { | |
e82bbd67 BG |
2610 | struct gpio_chardev_data *cdev = |
2611 | container_of(nb, struct gpio_chardev_data, lineinfo_changed_nb); | |
aad95584 | 2612 | struct gpio_v2_line_info_changed chg; |
925ca369 KG |
2613 | struct gpio_desc *desc = data; |
2614 | int ret; | |
2615 | ||
e2b781c5 | 2616 | if (!test_bit(gpio_chip_hwgpio(desc), cdev->watched_lines)) |
925ca369 KG |
2617 | return NOTIFY_DONE; |
2618 | ||
2619 | memset(&chg, 0, sizeof(chg)); | |
925ca369 | 2620 | chg.event_type = action; |
aad95584 | 2621 | chg.timestamp_ns = ktime_get_ns(); |
925ca369 | 2622 | gpio_desc_to_lineinfo(desc, &chg.info); |
9344e34e | 2623 | supinfo_to_lineinfo(desc, &chg.info); |
925ca369 | 2624 | |
e2b781c5 | 2625 | ret = kfifo_in_spinlocked(&cdev->events, &chg, 1, &cdev->wait.lock); |
925ca369 | 2626 | if (ret) |
e2b781c5 | 2627 | wake_up_poll(&cdev->wait, EPOLLIN); |
925ca369 KG |
2628 | else |
2629 | pr_debug_ratelimited("lineinfo event FIFO is full - event dropped\n"); | |
2630 | ||
2631 | return NOTIFY_OK; | |
2632 | } | |
2633 | ||
d2e2586a BG |
2634 | static int gpio_device_unregistered_notify(struct notifier_block *nb, |
2635 | unsigned long action, void *data) | |
2636 | { | |
2637 | struct gpio_chardev_data *cdev = container_of(nb, | |
2638 | struct gpio_chardev_data, | |
2639 | device_unregistered_nb); | |
2640 | ||
2641 | wake_up_poll(&cdev->wait, EPOLLIN | EPOLLERR); | |
2642 | ||
2643 | return NOTIFY_OK; | |
2644 | } | |
2645 | ||
20bddcb4 KG |
2646 | static __poll_t lineinfo_watch_poll(struct file *file, |
2647 | struct poll_table_struct *pollt) | |
925ca369 | 2648 | { |
e2b781c5 | 2649 | struct gpio_chardev_data *cdev = file->private_data; |
925ca369 KG |
2650 | __poll_t events = 0; |
2651 | ||
d83cee3d | 2652 | guard(srcu)(&cdev->gdev->srcu); |
20bddcb4 | 2653 | |
8574b5b4 | 2654 | if (!rcu_access_pointer(cdev->gdev->chip)) |
533aae7c BG |
2655 | return EPOLLHUP | EPOLLERR; |
2656 | ||
e2b781c5 | 2657 | poll_wait(file, &cdev->wait, pollt); |
925ca369 | 2658 | |
e2b781c5 KG |
2659 | if (!kfifo_is_empty_spinlocked_noirqsave(&cdev->events, |
2660 | &cdev->wait.lock)) | |
925ca369 KG |
2661 | events = EPOLLIN | EPOLLRDNORM; |
2662 | ||
2663 | return events; | |
2664 | } | |
2665 | ||
20bddcb4 KG |
2666 | static ssize_t lineinfo_watch_read(struct file *file, char __user *buf, |
2667 | size_t count, loff_t *off) | |
925ca369 | 2668 | { |
e2b781c5 | 2669 | struct gpio_chardev_data *cdev = file->private_data; |
aad95584 | 2670 | struct gpio_v2_line_info_changed event; |
925ca369 KG |
2671 | ssize_t bytes_read = 0; |
2672 | int ret; | |
aad95584 | 2673 | size_t event_size; |
925ca369 | 2674 | |
d83cee3d | 2675 | guard(srcu)(&cdev->gdev->srcu); |
20bddcb4 | 2676 | |
8574b5b4 | 2677 | if (!rcu_access_pointer(cdev->gdev->chip)) |
533aae7c BG |
2678 | return -ENODEV; |
2679 | ||
aad95584 KG |
2680 | #ifndef CONFIG_GPIO_CDEV_V1 |
2681 | event_size = sizeof(struct gpio_v2_line_info_changed); | |
2682 | if (count < event_size) | |
925ca369 | 2683 | return -EINVAL; |
aad95584 | 2684 | #endif |
925ca369 KG |
2685 | |
2686 | do { | |
0ebeaab4 KG |
2687 | scoped_guard(spinlock, &cdev->wait.lock) { |
2688 | if (kfifo_is_empty(&cdev->events)) { | |
2689 | if (bytes_read) | |
2690 | return bytes_read; | |
2691 | ||
2692 | if (file->f_flags & O_NONBLOCK) | |
2693 | return -EAGAIN; | |
2694 | ||
2695 | ret = wait_event_interruptible_locked(cdev->wait, | |
2696 | !kfifo_is_empty(&cdev->events)); | |
2697 | if (ret) | |
2698 | return ret; | |
925ca369 | 2699 | } |
aad95584 | 2700 | #ifdef CONFIG_GPIO_CDEV_V1 |
0ebeaab4 KG |
2701 | /* must be after kfifo check so watch_abi_version is set */ |
2702 | if (atomic_read(&cdev->watch_abi_version) == 2) | |
2703 | event_size = sizeof(struct gpio_v2_line_info_changed); | |
2704 | else | |
2705 | event_size = sizeof(struct gpioline_info_changed); | |
2706 | if (count < event_size) | |
2707 | return -EINVAL; | |
aad95584 | 2708 | #endif |
0ebeaab4 KG |
2709 | ret = kfifo_out(&cdev->events, &event, 1); |
2710 | } | |
925ca369 KG |
2711 | if (ret != 1) { |
2712 | ret = -EIO; | |
2713 | break; | |
2714 | /* We should never get here. See lineevent_read(). */ | |
2715 | } | |
2716 | ||
aad95584 KG |
2717 | #ifdef CONFIG_GPIO_CDEV_V1 |
2718 | if (event_size == sizeof(struct gpio_v2_line_info_changed)) { | |
2719 | if (copy_to_user(buf + bytes_read, &event, event_size)) | |
2720 | return -EFAULT; | |
2721 | } else { | |
2722 | struct gpioline_info_changed event_v1; | |
2723 | ||
2724 | gpio_v2_line_info_changed_to_v1(&event, &event_v1); | |
2725 | if (copy_to_user(buf + bytes_read, &event_v1, | |
2726 | event_size)) | |
2727 | return -EFAULT; | |
2728 | } | |
2729 | #else | |
2730 | if (copy_to_user(buf + bytes_read, &event, event_size)) | |
925ca369 | 2731 | return -EFAULT; |
aad95584 KG |
2732 | #endif |
2733 | bytes_read += event_size; | |
925ca369 KG |
2734 | } while (count >= bytes_read + sizeof(event)); |
2735 | ||
2736 | return bytes_read; | |
2737 | } | |
2738 | ||
2739 | /** | |
2740 | * gpio_chrdev_open() - open the chardev for ioctl operations | |
2741 | * @inode: inode for this chardev | |
49bc5279 | 2742 | * @file: file struct for storing private data |
925ca369 KG |
2743 | * Returns 0 on success |
2744 | */ | |
49bc5279 | 2745 | static int gpio_chrdev_open(struct inode *inode, struct file *file) |
925ca369 KG |
2746 | { |
2747 | struct gpio_device *gdev = container_of(inode->i_cdev, | |
a18512e3 | 2748 | struct gpio_device, chrdev); |
e2b781c5 | 2749 | struct gpio_chardev_data *cdev; |
925ca369 KG |
2750 | int ret = -ENOMEM; |
2751 | ||
d83cee3d | 2752 | guard(srcu)(&gdev->srcu); |
bdbbae24 | 2753 | |
925ca369 | 2754 | /* Fail on open if the backing gpiochip is gone */ |
8574b5b4 | 2755 | if (!rcu_access_pointer(gdev->chip)) |
20bddcb4 | 2756 | return -ENODEV; |
925ca369 | 2757 | |
e2b781c5 KG |
2758 | cdev = kzalloc(sizeof(*cdev), GFP_KERNEL); |
2759 | if (!cdev) | |
20bddcb4 | 2760 | return -ENODEV; |
925ca369 | 2761 | |
3c7a47f6 | 2762 | cdev->watched_lines = bitmap_zalloc(gdev->ngpio, GFP_KERNEL); |
e2b781c5 KG |
2763 | if (!cdev->watched_lines) |
2764 | goto out_free_cdev; | |
925ca369 | 2765 | |
e2b781c5 KG |
2766 | init_waitqueue_head(&cdev->wait); |
2767 | INIT_KFIFO(cdev->events); | |
dc0989e3 | 2768 | cdev->gdev = gpio_device_get(gdev); |
925ca369 | 2769 | |
e2b781c5 | 2770 | cdev->lineinfo_changed_nb.notifier_call = lineinfo_changed_notify; |
17a7ca35 | 2771 | ret = blocking_notifier_chain_register(&gdev->line_state_notifier, |
e2b781c5 | 2772 | &cdev->lineinfo_changed_nb); |
925ca369 KG |
2773 | if (ret) |
2774 | goto out_free_bitmap; | |
2775 | ||
d2e2586a BG |
2776 | cdev->device_unregistered_nb.notifier_call = |
2777 | gpio_device_unregistered_notify; | |
2778 | ret = blocking_notifier_chain_register(&gdev->device_notifier, | |
2779 | &cdev->device_unregistered_nb); | |
2780 | if (ret) | |
2781 | goto out_unregister_line_notifier; | |
2782 | ||
e2b781c5 | 2783 | file->private_data = cdev; |
925ca369 | 2784 | |
49bc5279 | 2785 | ret = nonseekable_open(inode, file); |
925ca369 | 2786 | if (ret) |
d2e2586a | 2787 | goto out_unregister_device_notifier; |
925ca369 KG |
2788 | |
2789 | return ret; | |
2790 | ||
d2e2586a BG |
2791 | out_unregister_device_notifier: |
2792 | blocking_notifier_chain_unregister(&gdev->device_notifier, | |
2793 | &cdev->device_unregistered_nb); | |
2794 | out_unregister_line_notifier: | |
17a7ca35 | 2795 | blocking_notifier_chain_unregister(&gdev->line_state_notifier, |
e2b781c5 | 2796 | &cdev->lineinfo_changed_nb); |
925ca369 | 2797 | out_free_bitmap: |
dc0989e3 | 2798 | gpio_device_put(gdev); |
e2b781c5 KG |
2799 | bitmap_free(cdev->watched_lines); |
2800 | out_free_cdev: | |
2801 | kfree(cdev); | |
925ca369 KG |
2802 | return ret; |
2803 | } | |
2804 | ||
2805 | /** | |
2806 | * gpio_chrdev_release() - close chardev after ioctl operations | |
2807 | * @inode: inode for this chardev | |
49bc5279 | 2808 | * @file: file struct for storing private data |
925ca369 KG |
2809 | * Returns 0 on success |
2810 | */ | |
49bc5279 | 2811 | static int gpio_chrdev_release(struct inode *inode, struct file *file) |
925ca369 | 2812 | { |
e2b781c5 KG |
2813 | struct gpio_chardev_data *cdev = file->private_data; |
2814 | struct gpio_device *gdev = cdev->gdev; | |
925ca369 | 2815 | |
d2e2586a BG |
2816 | blocking_notifier_chain_unregister(&gdev->device_notifier, |
2817 | &cdev->device_unregistered_nb); | |
17a7ca35 | 2818 | blocking_notifier_chain_unregister(&gdev->line_state_notifier, |
e2b781c5 | 2819 | &cdev->lineinfo_changed_nb); |
02f6b0e1 | 2820 | bitmap_free(cdev->watched_lines); |
dc0989e3 | 2821 | gpio_device_put(gdev); |
e2b781c5 | 2822 | kfree(cdev); |
925ca369 KG |
2823 | |
2824 | return 0; | |
2825 | } | |
2826 | ||
2827 | static const struct file_operations gpio_fileops = { | |
2828 | .release = gpio_chrdev_release, | |
2829 | .open = gpio_chrdev_open, | |
2830 | .poll = lineinfo_watch_poll, | |
2831 | .read = lineinfo_watch_read, | |
2832 | .owner = THIS_MODULE, | |
2833 | .llseek = no_llseek, | |
2834 | .unlocked_ioctl = gpio_ioctl, | |
2835 | #ifdef CONFIG_COMPAT | |
2836 | .compat_ioctl = gpio_ioctl_compat, | |
2837 | #endif | |
2838 | }; | |
2839 | ||
2840 | int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt) | |
2841 | { | |
d83cee3d | 2842 | struct gpio_chip *gc; |
925ca369 KG |
2843 | int ret; |
2844 | ||
2845 | cdev_init(&gdev->chrdev, &gpio_fileops); | |
2846 | gdev->chrdev.owner = THIS_MODULE; | |
2847 | gdev->dev.devt = MKDEV(MAJOR(devt), gdev->id); | |
2848 | ||
2849 | ret = cdev_device_add(&gdev->chrdev, &gdev->dev); | |
2850 | if (ret) | |
2851 | return ret; | |
2852 | ||
d83cee3d | 2853 | guard(srcu)(&gdev->srcu); |
91510d59 BG |
2854 | gc = srcu_dereference(gdev->chip, &gdev->srcu); |
2855 | if (!gc) | |
d83cee3d BG |
2856 | return -ENODEV; |
2857 | ||
2858 | chip_dbg(gc, "added GPIO chardev (%d:%d)\n", MAJOR(devt), gdev->id); | |
925ca369 KG |
2859 | |
2860 | return 0; | |
2861 | } | |
2862 | ||
2863 | void gpiolib_cdev_unregister(struct gpio_device *gdev) | |
2864 | { | |
2865 | cdev_device_del(&gdev->chrdev, &gdev->dev); | |
a067419b | 2866 | blocking_notifier_call_chain(&gdev->device_notifier, 0, NULL); |
925ca369 | 2867 | } |