2 * Copyright (c) 2014 Google, Inc
4 * SPDX-License-Identifier: GPL-2.0+
13 #include <dm/device-internal.h>
16 DECLARE_GLOBAL_DATA_PTR
;
18 #define I2C_MAX_OFFSET_LEN 4
20 /* Useful debugging function */
21 void i2c_dump_msgs(struct i2c_msg
*msg
, int nmsgs
)
25 for (i
= 0; i
< nmsgs
; i
++) {
26 struct i2c_msg
*m
= &msg
[i
];
28 printf(" %s %x len=%x", m
->flags
& I2C_M_RD
? "R" : "W",
30 if (!(m
->flags
& I2C_M_RD
))
31 printf(": %x", m
->buf
[0]);
37 * i2c_setup_offset() - Set up a new message with a chip offset
40 * @offset: Byte offset within chip
41 * @offset_buf: Place to put byte offset
42 * @msg: Message buffer
43 * @return 0 if OK, -EADDRNOTAVAIL if the offset length is 0. In that case the
44 * message is still set up but will not contain an offset.
46 static int i2c_setup_offset(struct dm_i2c_chip
*chip
, uint offset
,
47 uint8_t offset_buf
[], struct i2c_msg
*msg
)
51 msg
->addr
= chip
->chip_addr
;
52 msg
->flags
= chip
->flags
& DM_I2C_CHIP_10BIT
? I2C_M_TEN
: 0;
53 msg
->len
= chip
->offset_len
;
54 msg
->buf
= offset_buf
;
55 if (!chip
->offset_len
)
56 return -EADDRNOTAVAIL
;
57 assert(chip
->offset_len
<= I2C_MAX_OFFSET_LEN
);
58 offset_len
= chip
->offset_len
;
60 *offset_buf
++ = offset
>> (8 * offset_len
);
65 static int i2c_read_bytewise(struct udevice
*dev
, uint offset
,
66 uint8_t *buffer
, int len
)
68 struct dm_i2c_chip
*chip
= dev_get_parent_platdata(dev
);
69 struct udevice
*bus
= dev_get_parent(dev
);
70 struct dm_i2c_ops
*ops
= i2c_get_ops(bus
);
71 struct i2c_msg msg
[2], *ptr
;
72 uint8_t offset_buf
[I2C_MAX_OFFSET_LEN
];
76 for (i
= 0; i
< len
; i
++) {
77 if (i2c_setup_offset(chip
, offset
+ i
, offset_buf
, msg
))
80 ptr
->addr
= chip
->chip_addr
;
81 ptr
->flags
= msg
->flags
| I2C_M_RD
;
83 ptr
->buf
= &buffer
[i
];
86 ret
= ops
->xfer(bus
, msg
, ptr
- msg
);
94 static int i2c_write_bytewise(struct udevice
*dev
, uint offset
,
95 const uint8_t *buffer
, int len
)
97 struct dm_i2c_chip
*chip
= dev_get_parent_platdata(dev
);
98 struct udevice
*bus
= dev_get_parent(dev
);
99 struct dm_i2c_ops
*ops
= i2c_get_ops(bus
);
100 struct i2c_msg msg
[1];
101 uint8_t buf
[I2C_MAX_OFFSET_LEN
+ 1];
105 for (i
= 0; i
< len
; i
++) {
106 if (i2c_setup_offset(chip
, offset
+ i
, buf
, msg
))
108 buf
[msg
->len
++] = buffer
[i
];
110 ret
= ops
->xfer(bus
, msg
, 1);
118 int dm_i2c_read(struct udevice
*dev
, uint offset
, uint8_t *buffer
, int len
)
120 struct dm_i2c_chip
*chip
= dev_get_parent_platdata(dev
);
121 struct udevice
*bus
= dev_get_parent(dev
);
122 struct dm_i2c_ops
*ops
= i2c_get_ops(bus
);
123 struct i2c_msg msg
[2], *ptr
;
124 uint8_t offset_buf
[I2C_MAX_OFFSET_LEN
];
129 if (chip
->flags
& DM_I2C_CHIP_RD_ADDRESS
)
130 return i2c_read_bytewise(dev
, offset
, buffer
, len
);
132 if (!i2c_setup_offset(chip
, offset
, offset_buf
, ptr
))
136 ptr
->addr
= chip
->chip_addr
;
137 ptr
->flags
= chip
->flags
& DM_I2C_CHIP_10BIT
? I2C_M_TEN
: 0;
138 ptr
->flags
|= I2C_M_RD
;
143 msg_count
= ptr
- msg
;
145 return ops
->xfer(bus
, msg
, msg_count
);
148 int dm_i2c_write(struct udevice
*dev
, uint offset
, const uint8_t *buffer
,
151 struct dm_i2c_chip
*chip
= dev_get_parent_platdata(dev
);
152 struct udevice
*bus
= dev_get_parent(dev
);
153 struct dm_i2c_ops
*ops
= i2c_get_ops(bus
);
154 struct i2c_msg msg
[1];
159 if (chip
->flags
& DM_I2C_CHIP_WR_ADDRESS
)
160 return i2c_write_bytewise(dev
, offset
, buffer
, len
);
162 * The simple approach would be to send two messages here: one to
163 * set the offset and one to write the bytes. However some drivers
164 * will not be expecting this, and some chips won't like how the
165 * driver presents this on the I2C bus.
167 * The API does not support separate offset and data. We could extend
168 * it with a flag indicating that there is data in the next message
169 * that needs to be processed in the same transaction. We could
170 * instead add an additional buffer to each message. For now, handle
171 * this in the uclass since it isn't clear what the impact on drivers
172 * would be with this extra complication. Unfortunately this means
173 * copying the message.
175 * Use the stack for small messages, malloc() for larger ones. We
176 * need to allow space for the offset (up to 4 bytes) and the message
180 uint8_t buf
[I2C_MAX_OFFSET_LEN
+ len
];
182 i2c_setup_offset(chip
, offset
, buf
, msg
);
184 memcpy(buf
+ chip
->offset_len
, buffer
, len
);
186 return ops
->xfer(bus
, msg
, 1);
191 buf
= malloc(I2C_MAX_OFFSET_LEN
+ len
);
194 i2c_setup_offset(chip
, offset
, buf
, msg
);
196 memcpy(buf
+ chip
->offset_len
, buffer
, len
);
198 ret
= ops
->xfer(bus
, msg
, 1);
204 int dm_i2c_xfer(struct udevice
*dev
, struct i2c_msg
*msg
, int nmsgs
)
206 struct udevice
*bus
= dev_get_parent(dev
);
207 struct dm_i2c_ops
*ops
= i2c_get_ops(bus
);
212 return ops
->xfer(bus
, msg
, nmsgs
);
215 int dm_i2c_reg_read(struct udevice
*dev
, uint offset
)
220 ret
= dm_i2c_read(dev
, offset
, &val
, 1);
227 int dm_i2c_reg_write(struct udevice
*dev
, uint offset
, uint value
)
231 return dm_i2c_write(dev
, offset
, &val
, 1);
235 * i2c_probe_chip() - probe for a chip on a bus
238 * @chip_addr: Chip address to probe
239 * @flags: Flags for the chip
240 * @return 0 if found, -ENOSYS if the driver is invalid, -EREMOTEIO if the chip
241 * does not respond to probe
243 static int i2c_probe_chip(struct udevice
*bus
, uint chip_addr
,
244 enum dm_i2c_chip_flags chip_flags
)
246 struct dm_i2c_ops
*ops
= i2c_get_ops(bus
);
247 struct i2c_msg msg
[1];
250 if (ops
->probe_chip
) {
251 ret
= ops
->probe_chip(bus
, chip_addr
, chip_flags
);
252 if (!ret
|| ret
!= -ENOSYS
)
259 /* Probe with a zero-length message */
260 msg
->addr
= chip_addr
;
261 msg
->flags
= chip_flags
& DM_I2C_CHIP_10BIT
? I2C_M_TEN
: 0;
265 return ops
->xfer(bus
, msg
, 1);
268 static int i2c_bind_driver(struct udevice
*bus
, uint chip_addr
, uint offset_len
,
269 struct udevice
**devp
)
271 struct dm_i2c_chip
*chip
;
276 snprintf(name
, sizeof(name
), "generic_%x", chip_addr
);
280 ret
= device_bind_driver(bus
, "i2c_generic_chip_drv", str
, &dev
);
281 debug("%s: device_bind_driver: ret=%d\n", __func__
, ret
);
285 /* Tell the device what we know about it */
286 chip
= dev_get_parent_platdata(dev
);
287 chip
->chip_addr
= chip_addr
;
288 chip
->offset_len
= offset_len
;
289 ret
= device_probe(dev
);
290 debug("%s: device_probe: ret=%d\n", __func__
, ret
);
299 * If the device failed to probe, unbind it. There is nothing there
300 * on the bus so we don't want to leave it lying around
308 int i2c_get_chip(struct udevice
*bus
, uint chip_addr
, uint offset_len
,
309 struct udevice
**devp
)
313 debug("%s: Searching bus '%s' for address %02x: ", __func__
,
314 bus
->name
, chip_addr
);
315 for (device_find_first_child(bus
, &dev
); dev
;
316 device_find_next_child(&dev
)) {
317 struct dm_i2c_chip
*chip
= dev_get_parent_platdata(dev
);
320 if (chip
->chip_addr
== chip_addr
) {
321 ret
= device_probe(dev
);
322 debug("found, ret=%d\n", ret
);
329 debug("not found\n");
330 return i2c_bind_driver(bus
, chip_addr
, offset_len
, devp
);
333 int i2c_get_chip_for_busnum(int busnum
, int chip_addr
, uint offset_len
,
334 struct udevice
**devp
)
339 ret
= uclass_get_device_by_seq(UCLASS_I2C
, busnum
, &bus
);
341 debug("Cannot find I2C bus %d\n", busnum
);
344 ret
= i2c_get_chip(bus
, chip_addr
, offset_len
, devp
);
346 debug("Cannot find I2C chip %02x on bus %d\n", chip_addr
,
354 int dm_i2c_probe(struct udevice
*bus
, uint chip_addr
, uint chip_flags
,
355 struct udevice
**devp
)
361 /* First probe that chip */
362 ret
= i2c_probe_chip(bus
, chip_addr
, chip_flags
);
363 debug("%s: bus='%s', address %02x, ret=%d\n", __func__
, bus
->name
,
368 /* The chip was found, see if we have a driver, and probe it */
369 ret
= i2c_get_chip(bus
, chip_addr
, 1, devp
);
370 debug("%s: i2c_get_chip: ret=%d\n", __func__
, ret
);
375 int dm_i2c_set_bus_speed(struct udevice
*bus
, unsigned int speed
)
377 struct dm_i2c_ops
*ops
= i2c_get_ops(bus
);
378 struct dm_i2c_bus
*i2c
= dev_get_uclass_priv(bus
);
382 * If we have a method, call it. If not then the driver probably wants
383 * to deal with speed changes on the next transfer. It can easily read
384 * the current speed from this uclass
386 if (ops
->set_bus_speed
) {
387 ret
= ops
->set_bus_speed(bus
, speed
);
391 i2c
->speed_hz
= speed
;
396 int dm_i2c_get_bus_speed(struct udevice
*bus
)
398 struct dm_i2c_ops
*ops
= i2c_get_ops(bus
);
399 struct dm_i2c_bus
*i2c
= dev_get_uclass_priv(bus
);
401 if (!ops
->get_bus_speed
)
402 return i2c
->speed_hz
;
404 return ops
->get_bus_speed(bus
);
407 int i2c_set_chip_flags(struct udevice
*dev
, uint flags
)
409 struct udevice
*bus
= dev
->parent
;
410 struct dm_i2c_chip
*chip
= dev_get_parent_platdata(dev
);
411 struct dm_i2c_ops
*ops
= i2c_get_ops(bus
);
414 if (ops
->set_flags
) {
415 ret
= ops
->set_flags(dev
, flags
);
424 int i2c_get_chip_flags(struct udevice
*dev
, uint
*flagsp
)
426 struct dm_i2c_chip
*chip
= dev_get_parent_platdata(dev
);
428 *flagsp
= chip
->flags
;
433 int i2c_set_chip_offset_len(struct udevice
*dev
, uint offset_len
)
435 struct dm_i2c_chip
*chip
= dev_get_parent_platdata(dev
);
437 if (offset_len
> I2C_MAX_OFFSET_LEN
)
439 chip
->offset_len
= offset_len
;
444 int i2c_get_chip_offset_len(struct udevice
*dev
)
446 struct dm_i2c_chip
*chip
= dev_get_parent_platdata(dev
);
448 return chip
->offset_len
;
451 int i2c_deblock(struct udevice
*bus
)
453 struct dm_i2c_ops
*ops
= i2c_get_ops(bus
);
456 * We could implement a software deblocking here if we could get
457 * access to the GPIOs used by I2C, and switch them to GPIO mode
458 * and then back to I2C. This is somewhat beyond our powers in
459 * driver model at present, so for now just fail.
461 * See https://patchwork.ozlabs.org/patch/399040/
466 return ops
->deblock(bus
);
469 #if CONFIG_IS_ENABLED(OF_CONTROL)
470 int i2c_chip_ofdata_to_platdata(const void *blob
, int node
,
471 struct dm_i2c_chip
*chip
)
473 chip
->offset_len
= fdtdec_get_int(gd
->fdt_blob
, node
,
474 "u-boot,i2c-offset-len", 1);
476 chip
->chip_addr
= fdtdec_get_int(gd
->fdt_blob
, node
, "reg", -1);
477 if (chip
->chip_addr
== -1) {
478 debug("%s: I2C Node '%s' has no 'reg' property\n", __func__
,
479 fdt_get_name(blob
, node
, NULL
));
487 static int i2c_post_probe(struct udevice
*dev
)
489 #if CONFIG_IS_ENABLED(OF_CONTROL)
490 struct dm_i2c_bus
*i2c
= dev_get_uclass_priv(dev
);
492 i2c
->speed_hz
= fdtdec_get_int(gd
->fdt_blob
, dev
->of_offset
,
493 "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_offset
== -1)
509 return i2c_chip_ofdata_to_platdata(gd
->fdt_blob
, dev
->of_offset
, plat
);
515 UCLASS_DRIVER(i2c
) = {
518 .flags
= DM_UC_FLAG_SEQ_ALIAS
,
519 #if CONFIG_IS_ENABLED(OF_CONTROL)
520 .post_bind
= dm_scan_fdt_dev
,
522 .post_probe
= i2c_post_probe
,
523 .per_device_auto_alloc_size
= sizeof(struct dm_i2c_bus
),
524 .per_child_platdata_auto_alloc_size
= sizeof(struct dm_i2c_chip
),
525 .child_post_bind
= i2c_child_post_bind
,
528 UCLASS_DRIVER(i2c_generic
) = {
529 .id
= UCLASS_I2C_GENERIC
,
530 .name
= "i2c_generic",
533 U_BOOT_DRIVER(i2c_generic_chip_drv
) = {
534 .name
= "i2c_generic_chip_drv",
535 .id
= UCLASS_I2C_GENERIC
,