2 * Copyright (c) 2014 Google, Inc
4 * SPDX-License-Identifier: GPL-2.0+
12 #include <dm/device-internal.h>
15 DECLARE_GLOBAL_DATA_PTR
;
17 #define I2C_MAX_OFFSET_LEN 4
19 /* Useful debugging function */
20 void i2c_dump_msgs(struct i2c_msg
*msg
, int nmsgs
)
24 for (i
= 0; i
< nmsgs
; i
++) {
25 struct i2c_msg
*m
= &msg
[i
];
27 printf(" %s %x len=%x", m
->flags
& I2C_M_RD
? "R" : "W",
29 if (!(m
->flags
& I2C_M_RD
))
30 printf(": %x", m
->buf
[0]);
36 * i2c_setup_offset() - Set up a new message with a chip offset
39 * @offset: Byte offset within chip
40 * @offset_buf: Place to put byte offset
41 * @msg: Message buffer
42 * @return 0 if OK, -EADDRNOTAVAIL if the offset length is 0. In that case the
43 * message is still set up but will not contain an offset.
45 static int i2c_setup_offset(struct dm_i2c_chip
*chip
, uint offset
,
46 uint8_t offset_buf
[], struct i2c_msg
*msg
)
50 msg
->addr
= chip
->chip_addr
;
51 msg
->flags
= chip
->flags
& DM_I2C_CHIP_10BIT
? I2C_M_TEN
: 0;
52 msg
->len
= chip
->offset_len
;
53 msg
->buf
= offset_buf
;
54 if (!chip
->offset_len
)
55 return -EADDRNOTAVAIL
;
56 assert(chip
->offset_len
<= I2C_MAX_OFFSET_LEN
);
57 offset_len
= chip
->offset_len
;
59 *offset_buf
++ = offset
>> (8 * offset_len
);
64 static int i2c_read_bytewise(struct udevice
*dev
, uint offset
,
65 uint8_t *buffer
, int len
)
67 struct dm_i2c_chip
*chip
= dev_get_parent_platdata(dev
);
68 struct udevice
*bus
= dev_get_parent(dev
);
69 struct dm_i2c_ops
*ops
= i2c_get_ops(bus
);
70 struct i2c_msg msg
[2], *ptr
;
71 uint8_t offset_buf
[I2C_MAX_OFFSET_LEN
];
75 for (i
= 0; i
< len
; i
++) {
76 if (i2c_setup_offset(chip
, offset
+ i
, offset_buf
, msg
))
79 ptr
->addr
= chip
->chip_addr
;
80 ptr
->flags
= msg
->flags
| I2C_M_RD
;
82 ptr
->buf
= &buffer
[i
];
85 ret
= ops
->xfer(bus
, msg
, ptr
- msg
);
93 static int i2c_write_bytewise(struct udevice
*dev
, uint offset
,
94 const uint8_t *buffer
, int len
)
96 struct dm_i2c_chip
*chip
= dev_get_parent_platdata(dev
);
97 struct udevice
*bus
= dev_get_parent(dev
);
98 struct dm_i2c_ops
*ops
= i2c_get_ops(bus
);
99 struct i2c_msg msg
[1];
100 uint8_t buf
[I2C_MAX_OFFSET_LEN
+ 1];
104 for (i
= 0; i
< len
; i
++) {
105 if (i2c_setup_offset(chip
, offset
+ i
, buf
, msg
))
107 buf
[msg
->len
++] = buffer
[i
];
109 ret
= ops
->xfer(bus
, msg
, 1);
117 int dm_i2c_read(struct udevice
*dev
, uint offset
, uint8_t *buffer
, int len
)
119 struct dm_i2c_chip
*chip
= dev_get_parent_platdata(dev
);
120 struct udevice
*bus
= dev_get_parent(dev
);
121 struct dm_i2c_ops
*ops
= i2c_get_ops(bus
);
122 struct i2c_msg msg
[2], *ptr
;
123 uint8_t offset_buf
[I2C_MAX_OFFSET_LEN
];
128 if (chip
->flags
& DM_I2C_CHIP_RD_ADDRESS
)
129 return i2c_read_bytewise(dev
, offset
, buffer
, len
);
131 if (!i2c_setup_offset(chip
, offset
, offset_buf
, ptr
))
135 ptr
->addr
= chip
->chip_addr
;
136 ptr
->flags
= chip
->flags
& DM_I2C_CHIP_10BIT
? I2C_M_TEN
: 0;
137 ptr
->flags
|= I2C_M_RD
;
142 msg_count
= ptr
- msg
;
144 return ops
->xfer(bus
, msg
, msg_count
);
147 int dm_i2c_write(struct udevice
*dev
, uint offset
, const uint8_t *buffer
,
150 struct dm_i2c_chip
*chip
= dev_get_parent_platdata(dev
);
151 struct udevice
*bus
= dev_get_parent(dev
);
152 struct dm_i2c_ops
*ops
= i2c_get_ops(bus
);
153 struct i2c_msg msg
[1];
158 if (chip
->flags
& DM_I2C_CHIP_WR_ADDRESS
)
159 return i2c_write_bytewise(dev
, offset
, buffer
, len
);
161 * The simple approach would be to send two messages here: one to
162 * set the offset and one to write the bytes. However some drivers
163 * will not be expecting this, and some chips won't like how the
164 * driver presents this on the I2C bus.
166 * The API does not support separate offset and data. We could extend
167 * it with a flag indicating that there is data in the next message
168 * that needs to be processed in the same transaction. We could
169 * instead add an additional buffer to each message. For now, handle
170 * this in the uclass since it isn't clear what the impact on drivers
171 * would be with this extra complication. Unfortunately this means
172 * copying the message.
174 * Use the stack for small messages, malloc() for larger ones. We
175 * need to allow space for the offset (up to 4 bytes) and the message
179 uint8_t buf
[I2C_MAX_OFFSET_LEN
+ len
];
181 i2c_setup_offset(chip
, offset
, buf
, msg
);
183 memcpy(buf
+ chip
->offset_len
, buffer
, len
);
185 return ops
->xfer(bus
, msg
, 1);
190 buf
= malloc(I2C_MAX_OFFSET_LEN
+ len
);
193 i2c_setup_offset(chip
, offset
, buf
, msg
);
195 memcpy(buf
+ chip
->offset_len
, buffer
, len
);
197 ret
= ops
->xfer(bus
, msg
, 1);
203 int dm_i2c_xfer(struct udevice
*dev
, struct i2c_msg
*msg
, int nmsgs
)
205 struct udevice
*bus
= dev_get_parent(dev
);
206 struct dm_i2c_ops
*ops
= i2c_get_ops(bus
);
211 return ops
->xfer(bus
, msg
, nmsgs
);
214 int dm_i2c_reg_read(struct udevice
*dev
, uint offset
)
219 ret
= dm_i2c_read(dev
, offset
, &val
, 1);
226 int dm_i2c_reg_write(struct udevice
*dev
, uint offset
, uint value
)
230 return dm_i2c_write(dev
, offset
, &val
, 1);
234 * i2c_probe_chip() - probe for a chip on a bus
237 * @chip_addr: Chip address to probe
238 * @flags: Flags for the chip
239 * @return 0 if found, -ENOSYS if the driver is invalid, -EREMOTEIO if the chip
240 * does not respond to probe
242 static int i2c_probe_chip(struct udevice
*bus
, uint chip_addr
,
243 enum dm_i2c_chip_flags chip_flags
)
245 struct dm_i2c_ops
*ops
= i2c_get_ops(bus
);
246 struct i2c_msg msg
[1];
249 if (ops
->probe_chip
) {
250 ret
= ops
->probe_chip(bus
, chip_addr
, chip_flags
);
251 if (!ret
|| ret
!= -ENOSYS
)
258 /* Probe with a zero-length message */
259 msg
->addr
= chip_addr
;
260 msg
->flags
= chip_flags
& DM_I2C_CHIP_10BIT
? I2C_M_TEN
: 0;
264 return ops
->xfer(bus
, msg
, 1);
267 static int i2c_bind_driver(struct udevice
*bus
, uint chip_addr
, uint offset_len
,
268 struct udevice
**devp
)
270 struct dm_i2c_chip
*chip
;
275 snprintf(name
, sizeof(name
), "generic_%x", chip_addr
);
279 ret
= device_bind_driver(bus
, "i2c_generic_chip_drv", str
, &dev
);
280 debug("%s: device_bind_driver: ret=%d\n", __func__
, ret
);
284 /* Tell the device what we know about it */
285 chip
= dev_get_parent_platdata(dev
);
286 chip
->chip_addr
= chip_addr
;
287 chip
->offset_len
= offset_len
;
288 ret
= device_probe(dev
);
289 debug("%s: device_probe: ret=%d\n", __func__
, ret
);
298 * If the device failed to probe, unbind it. There is nothing there
299 * on the bus so we don't want to leave it lying around
307 int i2c_get_chip(struct udevice
*bus
, uint chip_addr
, uint offset_len
,
308 struct udevice
**devp
)
312 debug("%s: Searching bus '%s' for address %02x: ", __func__
,
313 bus
->name
, chip_addr
);
314 for (device_find_first_child(bus
, &dev
); dev
;
315 device_find_next_child(&dev
)) {
316 struct dm_i2c_chip
*chip
= dev_get_parent_platdata(dev
);
319 if (chip
->chip_addr
== chip_addr
) {
320 ret
= device_probe(dev
);
321 debug("found, ret=%d\n", ret
);
328 debug("not found\n");
329 return i2c_bind_driver(bus
, chip_addr
, offset_len
, devp
);
332 int i2c_get_chip_for_busnum(int busnum
, int chip_addr
, uint offset_len
,
333 struct udevice
**devp
)
338 ret
= uclass_get_device_by_seq(UCLASS_I2C
, busnum
, &bus
);
340 debug("Cannot find I2C bus %d\n", busnum
);
343 ret
= i2c_get_chip(bus
, chip_addr
, offset_len
, devp
);
345 debug("Cannot find I2C chip %02x on bus %d\n", chip_addr
,
353 int dm_i2c_probe(struct udevice
*bus
, uint chip_addr
, uint chip_flags
,
354 struct udevice
**devp
)
360 /* First probe that chip */
361 ret
= i2c_probe_chip(bus
, chip_addr
, chip_flags
);
362 debug("%s: bus='%s', address %02x, ret=%d\n", __func__
, bus
->name
,
367 /* The chip was found, see if we have a driver, and probe it */
368 ret
= i2c_get_chip(bus
, chip_addr
, 1, devp
);
369 debug("%s: i2c_get_chip: ret=%d\n", __func__
, ret
);
374 int dm_i2c_set_bus_speed(struct udevice
*bus
, unsigned int speed
)
376 struct dm_i2c_ops
*ops
= i2c_get_ops(bus
);
377 struct dm_i2c_bus
*i2c
= dev_get_uclass_priv(bus
);
381 * If we have a method, call it. If not then the driver probably wants
382 * to deal with speed changes on the next transfer. It can easily read
383 * the current speed from this uclass
385 if (ops
->set_bus_speed
) {
386 ret
= ops
->set_bus_speed(bus
, speed
);
390 i2c
->speed_hz
= speed
;
395 int dm_i2c_get_bus_speed(struct udevice
*bus
)
397 struct dm_i2c_ops
*ops
= i2c_get_ops(bus
);
398 struct dm_i2c_bus
*i2c
= dev_get_uclass_priv(bus
);
400 if (!ops
->get_bus_speed
)
401 return i2c
->speed_hz
;
403 return ops
->get_bus_speed(bus
);
406 int i2c_set_chip_flags(struct udevice
*dev
, uint flags
)
408 struct udevice
*bus
= dev
->parent
;
409 struct dm_i2c_chip
*chip
= dev_get_parent_platdata(dev
);
410 struct dm_i2c_ops
*ops
= i2c_get_ops(bus
);
413 if (ops
->set_flags
) {
414 ret
= ops
->set_flags(dev
, flags
);
423 int i2c_get_chip_flags(struct udevice
*dev
, uint
*flagsp
)
425 struct dm_i2c_chip
*chip
= dev_get_parent_platdata(dev
);
427 *flagsp
= chip
->flags
;
432 int i2c_set_chip_offset_len(struct udevice
*dev
, uint offset_len
)
434 struct dm_i2c_chip
*chip
= dev_get_parent_platdata(dev
);
436 if (offset_len
> I2C_MAX_OFFSET_LEN
)
438 chip
->offset_len
= offset_len
;
443 int i2c_get_chip_offset_len(struct udevice
*dev
)
445 struct dm_i2c_chip
*chip
= dev_get_parent_platdata(dev
);
447 return chip
->offset_len
;
450 int i2c_deblock(struct udevice
*bus
)
452 struct dm_i2c_ops
*ops
= i2c_get_ops(bus
);
455 * We could implement a software deblocking here if we could get
456 * access to the GPIOs used by I2C, and switch them to GPIO mode
457 * and then back to I2C. This is somewhat beyond our powers in
458 * driver model at present, so for now just fail.
460 * See https://patchwork.ozlabs.org/patch/399040/
465 return ops
->deblock(bus
);
468 #if CONFIG_IS_ENABLED(OF_CONTROL)
469 int i2c_chip_ofdata_to_platdata(struct udevice
*dev
, struct dm_i2c_chip
*chip
)
473 chip
->offset_len
= dev_read_u32_default(dev
, "u-boot,i2c-offset-len",
476 addr
= dev_read_u32_default(dev
, "reg", -1);
478 debug("%s: I2C Node '%s' has no 'reg' property %s\n", __func__
,
479 dev_read_name(dev
), dev
->name
);
482 chip
->chip_addr
= addr
;
488 static int i2c_post_probe(struct udevice
*dev
)
490 #if CONFIG_IS_ENABLED(OF_CONTROL)
491 struct dm_i2c_bus
*i2c
= dev_get_uclass_priv(dev
);
493 i2c
->speed_hz
= dev_read_u32_default(dev
, "clock-frequency", 100000);
495 return dm_i2c_set_bus_speed(dev
, i2c
->speed_hz
);
501 static int i2c_child_post_bind(struct udevice
*dev
)
503 #if CONFIG_IS_ENABLED(OF_CONTROL)
504 struct dm_i2c_chip
*plat
= dev_get_parent_platdata(dev
);
506 if (!dev_of_valid(dev
))
508 return i2c_chip_ofdata_to_platdata(dev
, plat
);
514 UCLASS_DRIVER(i2c
) = {
517 .flags
= DM_UC_FLAG_SEQ_ALIAS
,
518 #if CONFIG_IS_ENABLED(OF_CONTROL)
519 .post_bind
= dm_scan_fdt_dev
,
521 .post_probe
= i2c_post_probe
,
522 .per_device_auto_alloc_size
= sizeof(struct dm_i2c_bus
),
523 .per_child_platdata_auto_alloc_size
= sizeof(struct dm_i2c_chip
),
524 .child_post_bind
= i2c_child_post_bind
,
527 UCLASS_DRIVER(i2c_generic
) = {
528 .id
= UCLASS_I2C_GENERIC
,
529 .name
= "i2c_generic",
532 U_BOOT_DRIVER(i2c_generic_chip_drv
) = {
533 .name
= "i2c_generic_chip_drv",
534 .id
= UCLASS_I2C_GENERIC
,