aboutsummaryrefslogtreecommitdiff
path: root/drivers/i2c/i2c-uclass.c
blob: 49e23a0a4bf20d1662abfecf30cfe90c843bed59 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (c) 2014 Google, Inc
 */

#include <common.h>
#include <dm.h>
#include <errno.h>
#include <i2c.h>
#include <malloc.h>
#include <dm/device-internal.h>
#include <dm/lists.h>
#include <dm/pinctrl.h>
#ifdef CONFIG_DM_GPIO
#include <asm/gpio.h>
#endif

#define I2C_MAX_OFFSET_LEN	4

enum {
	PIN_SDA = 0,
	PIN_SCL,
	PIN_COUNT,
};

/* Useful debugging function */
void i2c_dump_msgs(struct i2c_msg *msg, int nmsgs)
{
	int i;

	for (i = 0; i < nmsgs; i++) {
		struct i2c_msg *m = &msg[i];

		printf("   %s %x len=%x", m->flags & I2C_M_RD ? "R" : "W",
		       msg->addr, msg->len);
		if (!(m->flags & I2C_M_RD))
			printf(": %x", m->buf[0]);
		printf("\n");
	}
}

/**
 * i2c_setup_offset() - Set up a new message with a chip offset
 *
 * @chip:	Chip to use
 * @offset:	Byte offset within chip
 * @offset_buf:	Place to put byte offset
 * @msg:	Message buffer
 * @return 0 if OK, -EADDRNOTAVAIL if the offset length is 0. In that case the
 * message is still set up but will not contain an offset.
 */
static int i2c_setup_offset(struct dm_i2c_chip *chip, uint offset,
			    uint8_t offset_buf[], struct i2c_msg *msg)
{
	int offset_len;

	msg->addr = chip->chip_addr;
	msg->flags = chip->flags & DM_I2C_CHIP_10BIT ? I2C_M_TEN : 0;
	msg->len = chip->offset_len;
	msg->buf = offset_buf;
	if (!chip->offset_len)
		return -EADDRNOTAVAIL;
	assert(chip->offset_len <= I2C_MAX_OFFSET_LEN);
	offset_len = chip->offset_len;
	while (offset_len--)
		*offset_buf++ = offset >> (8 * offset_len);

	return 0;
}

static int i2c_read_bytewise(struct udevice *dev, uint offset,
			     uint8_t *buffer, int len)
{
	struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);
	struct udevice *bus = dev_get_parent(dev);
	struct dm_i2c_ops *ops = i2c_get_ops(bus);
	struct i2c_msg msg[2], *ptr;
	uint8_t offset_buf[I2C_MAX_OFFSET_LEN];
	int ret;
	int i;

	for (i = 0; i < len; i++) {
		if (i2c_setup_offset(chip, offset + i, offset_buf, msg))
			return -EINVAL;
		ptr = msg + 1;
		ptr->addr = chip->chip_addr;
		ptr->flags = msg->flags | I2C_M_RD;
		ptr->len = 1;
		ptr->buf = &buffer[i];
		ptr++;

		ret = ops->xfer(bus, msg, ptr - msg);
		if (ret)
			return ret;
	}

	return 0;
}

static int i2c_write_bytewise(struct udevice *dev, uint offset,
			     const uint8_t *buffer, int len)
{
	struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);
	struct udevice *bus = dev_get_parent(dev);
	struct dm_i2c_ops *ops = i2c_get_ops(bus);
	struct i2c_msg msg[1];
	uint8_t buf[I2C_MAX_OFFSET_LEN + 1];
	int ret;
	int i;

	for (i = 0; i < len; i++) {
		if (i2c_setup_offset(chip, offset + i, buf, msg))
			return -EINVAL;
		buf[msg->len++] = buffer[i];

		ret = ops->xfer(bus, msg, 1);
		if (ret)
			return ret;
	}

	return 0;
}

int dm_i2c_read(struct udevice *dev, uint offset, uint8_t *buffer, int len)
{
	struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);
	struct udevice *bus = dev_get_parent(dev);
	struct dm_i2c_ops *ops = i2c_get_ops(bus);
	struct i2c_msg msg[2], *ptr;
	uint8_t offset_buf[I2C_MAX_OFFSET_LEN];
	int msg_count;

	if (!ops->xfer)
		return -ENOSYS;
	if (chip->flags & DM_I2C_CHIP_RD_ADDRESS)
		return i2c_read_bytewise(dev, offset, buffer, len);
	ptr = msg;
	if (!i2c_setup_offset(chip, offset, offset_buf, ptr))
		ptr++;

	if (len) {
		ptr->addr = chip->chip_addr;
		ptr->flags = chip->flags & DM_I2C_CHIP_10BIT ? I2C_M_TEN : 0;
		ptr->flags |= I2C_M_RD;
		ptr->len = len;
		ptr->buf = buffer;
		ptr++;
	}
	msg_count = ptr - msg;

	return ops->xfer(bus, msg, msg_count);
}

int dm_i2c_write(struct udevice *dev, uint offset, const uint8_t *buffer,
		 int len)
{
	struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);
	struct udevice *bus = dev_get_parent(dev);
	struct dm_i2c_ops *ops = i2c_get_ops(bus);
	struct i2c_msg msg[1];

	if (!ops->xfer)
		return -ENOSYS;

	if (chip->flags & DM_I2C_CHIP_WR_ADDRESS)
		return i2c_write_bytewise(dev, offset, buffer, len);
	/*
	 * The simple approach would be to send two messages here: one to
	 * set the offset and one to write the bytes. However some drivers
	 * will not be expecting this, and some chips won't like how the
	 * driver presents this on the I2C bus.
	 *
	 * The API does not support separate offset and data. We could extend
	 * it with a flag indicating that there is data in the next message
	 * that needs to be processed in the same transaction. We could
	 * instead add an additional buffer to each message. For now, handle
	 * this in the uclass since it isn't clear what the impact on drivers
	 * would be with this extra complication. Unfortunately this means
	 * copying the message.
	 *
	 * Use the stack for small messages, malloc() for larger ones. We
	 * need to allow space for the offset (up to 4 bytes) and the message
	 * itself.
	 */
	if (len < 64) {
		uint8_t buf[I2C_MAX_OFFSET_LEN + len];

		i2c_setup_offset(chip, offset, buf, msg);
		msg->len += len;
		memcpy(buf + chip->offset_len, buffer, len);

		return ops->xfer(bus, msg, 1);
	} else {
		uint8_t *buf;
		int ret;

		buf = malloc(I2C_MAX_OFFSET_LEN + len);
		if (!buf)
			return -ENOMEM;
		i2c_setup_offset(chip, offset, buf, msg);
		msg->len += len;
		memcpy(buf + chip->offset_len, buffer, len);

		ret = ops->xfer(bus, msg, 1);
		free(buf);
		return ret;
	}
}

int dm_i2c_xfer(struct udevice *dev, struct i2c_msg *msg, int nmsgs)
{
	struct udevice *bus = dev_get_parent(dev);
	struct dm_i2c_ops *ops = i2c_get_ops(bus);

	if (!ops->xfer)
		return -ENOSYS;

	return ops->xfer(bus, msg, nmsgs);
}

int dm_i2c_reg_read(struct udevice *dev, uint offset)
{
	uint8_t val;
	int ret;

	ret = dm_i2c_read(dev, offset, &val, 1);
	if (ret < 0)
		return ret;

	return val;
}

int dm_i2c_reg_write(struct udevice *dev, uint offset, uint value)
{
	uint8_t val = value;

	return dm_i2c_write(dev, offset, &val, 1);
}

/**
 * i2c_probe_chip() - probe for a chip on a bus
 *
 * @bus:	Bus to probe
 * @chip_addr:	Chip address to probe
 * @flags:	Flags for the chip
 * @return 0 if found, -ENOSYS if the driver is invalid, -EREMOTEIO if the chip
 * does not respond to probe
 */
static int i2c_probe_chip(struct udevice *bus, uint chip_addr,
			  enum dm_i2c_chip_flags chip_flags)
{
	struct dm_i2c_ops *ops = i2c_get_ops(bus);
	struct i2c_msg msg[1];
	int ret;

	if (ops->probe_chip) {
		ret = ops->probe_chip(bus, chip_addr, chip_flags);
		if (!ret || ret != -ENOSYS)
			return ret;
	}

	if (!ops->xfer)
		return -ENOSYS;

	/* Probe with a zero-length message */
	msg->addr = chip_addr;
	msg->flags = chip_flags & DM_I2C_CHIP_10BIT ? I2C_M_TEN : 0;
	msg->len = 0;
	msg->buf = NULL;

	return ops->xfer(bus, msg, 1);
}

static int i2c_bind_driver(struct udevice *bus, uint chip_addr, uint offset_len,
			   struct udevice **devp)
{
	struct dm_i2c_chip *chip;
	char name[30], *str;
	struct udevice *dev;
	int ret;

	snprintf(name, sizeof(name), "generic_%x", chip_addr);
	str = strdup(name);
	if (!str)
		return -ENOMEM;
	ret = device_bind_driver(bus, "i2c_generic_chip_drv", str, &dev);
	debug("%s:  device_bind_driver: ret=%d\n", __func__, ret);
	if (ret)
		goto err_bind;

	/* Tell the device what we know about it */
	chip = dev_get_parent_platdata(dev);
	chip->chip_addr = chip_addr;
	chip->offset_len = offset_len;
	ret = device_probe(dev);
	debug("%s:  device_probe: ret=%d\n", __func__, ret);
	if (ret)
		goto err_probe;

	*devp = dev;
	return 0;

err_probe:
	/*
	 * If the device failed to probe, unbind it. There is nothing there
	 * on the bus so we don't want to leave it lying around
	 */
	device_unbind(dev);
err_bind:
	free(str);
	return ret;
}

int i2c_get_chip(struct udevice *bus, uint chip_addr, uint offset_len,
		 struct udevice **devp)
{
	struct udevice *dev;

	debug("%s: Searching bus '%s' for address %02x: ", __func__,
	      bus->name, chip_addr);
	for (device_find_first_child(bus, &dev); dev;
			device_find_next_child(&dev)) {
		struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);
		int ret;

		if (chip->chip_addr == chip_addr) {
			ret = device_probe(dev);
			debug("found, ret=%d\n", ret);
			if (ret)
				return ret;
			*devp = dev;
			return 0;
		}
	}
	debug("not found\n");
	return i2c_bind_driver(bus, chip_addr, offset_len, devp);
}

int i2c_get_chip_for_busnum(int busnum, int chip_addr, uint offset_len,
			    struct udevice **devp)
{
	struct udevice *bus;
	int ret;

	ret = uclass_get_device_by_seq(UCLASS_I2C, busnum, &bus);
	if (ret) {
		debug("Cannot find I2C bus %d\n", busnum);
		return ret;
	}

	/* detect the presence of the chip on the bus */
	ret = i2c_probe_chip(bus, chip_addr, 0);
	debug("%s: bus='%s', address %02x, ret=%d\n", __func__, bus->name,
	      chip_addr, ret);
	if (ret) {
		debug("Cannot detect I2C chip %02x on bus %d\n", chip_addr,
		      busnum);
		return ret;
	}

	ret = i2c_get_chip(bus, chip_addr, offset_len, devp);
	if (ret) {
		debug("Cannot find I2C chip %02x on bus %d\n", chip_addr,
		      busnum);
		return ret;
	}

	return 0;
}

int dm_i2c_probe(struct udevice *bus, uint chip_addr, uint chip_flags,
		 struct udevice **devp)
{
	int ret;

	*devp = NULL;

	/* First probe that chip */
	ret = i2c_probe_chip(bus, chip_addr, chip_flags);
	debug("%s: bus='%s', address %02x, ret=%d\n", __func__, bus->name,
	      chip_addr, ret);
	if (ret)
		return ret;

	/* The chip was found, see if we have a driver, and probe it */
	ret = i2c_get_chip(bus, chip_addr, 1, devp);
	debug("%s:  i2c_get_chip: ret=%d\n", __func__, ret);

	return ret;
}

int dm_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
{
	struct dm_i2c_ops *ops = i2c_get_ops(bus);
	struct dm_i2c_bus *i2c = dev_get_uclass_priv(bus);
	int ret;

	/*
	 * If we have a method, call it. If not then the driver probably wants
	 * to deal with speed changes on the next transfer. It can easily read
	 * the current speed from this uclass
	 */
	if (ops->set_bus_speed) {
		ret = ops->set_bus_speed(bus, speed);
		if (ret)
			return ret;
	}
	i2c->speed_hz = speed;

	return 0;
}

int dm_i2c_get_bus_speed(struct udevice *bus)
{
	struct dm_i2c_ops *ops = i2c_get_ops(bus);
	struct dm_i2c_bus *i2c = dev_get_uclass_priv(bus);

	if (!ops->get_bus_speed)
		return i2c->speed_hz;

	return ops->get_bus_speed(bus);
}

int i2c_set_chip_flags(struct udevice *dev, uint flags)
{
	struct udevice *bus = dev->parent;
	struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);
	struct dm_i2c_ops *ops = i2c_get_ops(bus);
	int ret;

	if (ops->set_flags) {
		ret = ops->set_flags(dev, flags);
		if (ret)
			return ret;
	}
	chip->flags = flags;

	return 0;
}

int i2c_get_chip_flags(struct udevice *dev, uint *flagsp)
{
	struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);

	*flagsp = chip->flags;

	return 0;
}

int i2c_set_chip_offset_len(struct udevice *dev, uint offset_len)
{
	struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);

	if (offset_len > I2C_MAX_OFFSET_LEN)
		return -EINVAL;
	chip->offset_len = offset_len;

	return 0;
}

int i2c_get_chip_offset_len(struct udevice *dev)
{
	struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);

	return chip->offset_len;
}

#ifdef CONFIG_DM_GPIO
static void i2c_gpio_set_pin(struct gpio_desc *pin, int bit)
{
	if (bit)
		dm_gpio_set_dir_flags(pin, GPIOD_IS_IN);
	else
		dm_gpio_set_dir_flags(pin, GPIOD_IS_OUT |
					   GPIOD_ACTIVE_LOW |
					   GPIOD_IS_OUT_ACTIVE);
}

static int i2c_gpio_get_pin(struct gpio_desc *pin)
{
	return dm_gpio_get_value(pin);
}

static int i2c_deblock_gpio_loop(struct gpio_desc *sda_pin,
				 struct gpio_desc *scl_pin)
{
	int counter = 9;
	int ret = 0;

	i2c_gpio_set_pin(sda_pin, 1);
	i2c_gpio_set_pin(scl_pin, 1);
	udelay(5);

	/*  Toggle SCL until slave release SDA */
	while (counter-- >= 0) {
		i2c_gpio_set_pin(scl_pin, 1);
		udelay(5);
		i2c_gpio_set_pin(scl_pin, 0);
		udelay(5);
		if (i2c_gpio_get_pin(sda_pin))
			break;
	}

	/* Then, send I2C stop */
	i2c_gpio_set_pin(sda_pin, 0);
	udelay(5);

	i2c_gpio_set_pin(scl_pin, 1);
	udelay(5);

	i2c_gpio_set_pin(sda_pin, 1);
	udelay(5);

	if (!i2c_gpio_get_pin(sda_pin) || !i2c_gpio_get_pin(scl_pin))
		ret = -EREMOTEIO;

	return ret;
}

static int i2c_deblock_gpio(struct udevice *bus)
{
	struct gpio_desc gpios[PIN_COUNT];
	int ret, ret0;

	ret = gpio_request_list_by_name(bus, "gpios", gpios,
					ARRAY_SIZE(gpios), GPIOD_IS_IN);
	if (ret != ARRAY_SIZE(gpios)) {
		debug("%s: I2C Node '%s' has no 'gpios' property %s\n",
		      __func__, dev_read_name(bus), bus->name);
		if (ret >= 0) {
			gpio_free_list(bus, gpios, ret);
			ret = -ENOENT;
		}
		goto out;
	}

	ret = pinctrl_select_state(bus, "gpio");
	if (ret) {
		debug("%s: I2C Node '%s' has no 'gpio' pinctrl state. %s\n",
		      __func__, dev_read_name(bus), bus->name);
		goto out_no_pinctrl;
	}

	ret0 = i2c_deblock_gpio_loop(&gpios[PIN_SDA], &gpios[PIN_SCL]);

	ret = pinctrl_select_state(bus, "default");
	if (ret) {
		debug("%s: I2C Node '%s' has no 'default' pinctrl state. %s\n",
		      __func__, dev_read_name(bus), bus->name);
	}

	ret = !ret ? ret0 : ret;

out_no_pinctrl:
	gpio_free_list(bus, gpios, ARRAY_SIZE(gpios));
out:
	return ret;
}
#else
static int i2c_deblock_gpio(struct udevice *bus)
{
	return -ENOSYS;
}
#endif // CONFIG_DM_GPIO

int i2c_deblock(struct udevice *bus)
{
	struct dm_i2c_ops *ops = i2c_get_ops(bus);

	if (!ops->deblock)
		return i2c_deblock_gpio(bus);

	return ops->deblock(bus);
}

#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
int i2c_chip_ofdata_to_platdata(struct udevice *dev, struct dm_i2c_chip *chip)
{
	int addr;

	chip->offset_len = dev_read_u32_default(dev, "u-boot,i2c-offset-len",
						1);
	chip->flags = 0;
	addr = dev_read_u32_default(dev, "reg", -1);
	if (addr == -1) {
		debug("%s: I2C Node '%s' has no 'reg' property %s\n", __func__,
		      dev_read_name(dev), dev->name);
		return -EINVAL;
	}
	chip->chip_addr = addr;

	return 0;
}
#endif

static int i2c_post_probe(struct udevice *dev)
{
#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
	struct dm_i2c_bus *i2c = dev_get_uclass_priv(dev);

	i2c->speed_hz = dev_read_u32_default(dev, "clock-frequency", 100000);

	return dm_i2c_set_bus_speed(dev, i2c->speed_hz);
#else
	return 0;
#endif
}

static int i2c_child_post_bind(struct udevice *dev)
{
#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
	struct dm_i2c_chip *plat = dev_get_parent_platdata(dev);

	if (!dev_of_valid(dev))
		return 0;
	return i2c_chip_ofdata_to_platdata(dev, plat);
#else
	return 0;
#endif
}

struct i2c_priv {
	int max_id;
};

static int i2c_post_bind(struct udevice *dev)
{
	struct uclass *class = dev->uclass;
	struct i2c_priv *priv = class->priv;
	int ret = 0;

	/* Just for sure */
	if (!priv)
		return -ENOMEM;

	debug("%s: %s, req_seq=%d\n", __func__, dev->name, dev->req_seq);

	/* if there is no alias ID, use the first free */
	if (dev->req_seq == -1)
		dev->req_seq = ++priv->max_id;

	debug("%s: %s, new req_seq=%d\n", __func__, dev->name, dev->req_seq);

#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
	ret = dm_scan_fdt_dev(dev);
#endif
	return ret;
}

int i2c_uclass_init(struct uclass *class)
{
	struct i2c_priv *priv = class->priv;

	/* Just for sure */
	if (!priv)
		return -ENOMEM;

	/* Get the last allocated alias. */
#if CONFIG_IS_ENABLED(OF_CONTROL)
	priv->max_id = dev_read_alias_highest_id("i2c");
#else
	priv->max_id = -1;
#endif

	debug("%s: highest alias id is %d\n", __func__, priv->max_id);

	return 0;
}

UCLASS_DRIVER(i2c) = {
	.id		= UCLASS_I2C,
	.name		= "i2c",
	.flags		= DM_UC_FLAG_SEQ_ALIAS,
	.post_bind	= i2c_post_bind,
	.init		= i2c_uclass_init,
	.priv_auto_alloc_size = sizeof(struct i2c_priv),
	.post_probe	= i2c_post_probe,
	.per_device_auto_alloc_size = sizeof(struct dm_i2c_bus),
	.per_child_platdata_auto_alloc_size = sizeof(struct dm_i2c_chip),
	.child_post_bind = i2c_child_post_bind,
};

UCLASS_DRIVER(i2c_generic) = {
	.id		= UCLASS_I2C_GENERIC,
	.name		= "i2c_generic",
};

U_BOOT_DRIVER(i2c_generic_chip_drv) = {
	.name		= "i2c_generic_chip_drv",
	.id		= UCLASS_I2C_GENERIC,
};