aboutsummaryrefslogblamecommitdiffstats
path: root/drivers/gpio/sx150x.c
blob: b42f42ca70c3c9454bb00ff7cf2e8505f74e482d (plain) (tree)
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




































































































































































































































































































































































































































































































































































































































































                                                                                
/* Copyright (c) 2010, Code Aurora Forum. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */
#include <linux/gpio.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/i2c/sx150x.h>

struct sx150x_device_data {
	u8 reg_pullup;
	u8 reg_pulldn;
	u8 reg_drain;
	u8 reg_polarity;
	u8 reg_dir;
	u8 reg_data;
	u8 reg_irq_mask;
	u8 reg_irq_src;
	u8 reg_sense;
	u8 reg_clock;
	u8 reg_misc;
	u8 reg_reset;
	u8 ngpios;
};

struct sx150x_chip {
	struct gpio_chip                 gpio_chip;
	struct i2c_client               *client;
	const struct sx150x_device_data *dev_cfg;
	int                              irq_summary;
	int                              irq_base;
	u32                              irq_sense;
	unsigned long                    irq_set_type_pending;
	struct irq_chip                  irq_chip;
	struct mutex                     lock;
};

static const struct sx150x_device_data sx150x_devices[] = {
	[0] = { /* sx1508q */
		.reg_pullup   = 0x03,
		.reg_pulldn   = 0x04,
		.reg_drain    = 0x05,
		.reg_polarity = 0x06,
		.reg_dir      = 0x07,
		.reg_data     = 0x08,
		.reg_irq_mask = 0x09,
		.reg_irq_src  = 0x0c,
		.reg_sense    = 0x0b,
		.reg_clock    = 0x0f,
		.reg_misc     = 0x10,
		.reg_reset    = 0x7d,
		.ngpios       = 8
	},
	[1] = { /* sx1509q */
		.reg_pullup   = 0x07,
		.reg_pulldn   = 0x09,
		.reg_drain    = 0x0b,
		.reg_polarity = 0x0d,
		.reg_dir      = 0x0f,
		.reg_data     = 0x11,
		.reg_irq_mask = 0x13,
		.reg_irq_src  = 0x19,
		.reg_sense    = 0x17,
		.reg_clock    = 0x1e,
		.reg_misc     = 0x1f,
		.reg_reset    = 0x7d,
		.ngpios       = 16
	},
};

static const struct i2c_device_id sx150x_id[] = {
	{"sx1508q", 0},
	{"sx1509q", 1},
	{}
};
MODULE_DEVICE_TABLE(i2c, sx150x_id);

static s32 sx150x_i2c_write(struct i2c_client *client, u8 reg, u8 val)
{
	s32 err = i2c_smbus_write_byte_data(client, reg, val);

	if (err < 0)
		dev_warn(&client->dev,
			"i2c write fail: can't write %02x to %02x: %d\n",
			val, reg, err);
	return err;
}

static s32 sx150x_i2c_read(struct i2c_client *client, u8 reg, u8 *val)
{
	s32 err = i2c_smbus_read_byte_data(client, reg);

	if (err >= 0)
		*val = err;
	else
		dev_warn(&client->dev,
			"i2c read fail: can't read from %02x: %d\n",
			reg, err);
	return err;
}

static inline bool offset_is_oscio(struct sx150x_chip *chip, unsigned offset)
{
	return (chip->dev_cfg->ngpios == offset);
}

/*
 * These utility functions solve the common problem of locating and setting
 * configuration bits.  Configuration bits are grouped into registers
 * whose indexes increase downwards.  For example, with eight-bit registers,
 * sixteen gpios would have their config bits grouped in the following order:
 * REGISTER N-1 [ f e d c b a 9 8 ]
 *          N   [ 7 6 5 4 3 2 1 0 ]
 *
 * For multi-bit configurations, the pattern gets wider:
 * REGISTER N-3 [ f f e e d d c c ]
 *          N-2 [ b b a a 9 9 8 8 ]
 *          N-1 [ 7 7 6 6 5 5 4 4 ]
 *          N   [ 3 3 2 2 1 1 0 0 ]
 *
 * Given the address of the starting register 'N', the index of the gpio
 * whose configuration we seek to change, and the width in bits of that
 * configuration, these functions allow us to locate the correct
 * register and mask the correct bits.
 */
static inline void sx150x_find_cfg(u8 offset, u8 width,
				u8 *reg, u8 *mask, u8 *shift)
{
	*reg   -= offset * width / 8;
	*mask   = (1 << width) - 1;
	*shift  = (offset * width) % 8;
	*mask <<= *shift;
}

static s32 sx150x_write_cfg(struct sx150x_chip *chip,
			u8 offset, u8 width, u8 reg, u8 val)
{
	u8  mask;
	u8  data;
	u8  shift;
	s32 err;

	sx150x_find_cfg(offset, width, &reg, &mask, &shift);
	err = sx150x_i2c_read(chip->client, reg, &data);
	if (err < 0)
		return err;

	data &= ~mask;
	data |= (val << shift) & mask;
	return sx150x_i2c_write(chip->client, reg, data);
}

static int sx150x_get_io(struct sx150x_chip *chip, unsigned offset)
{
	u8  reg = chip->dev_cfg->reg_data;
	u8  mask;
	u8  data;
	u8  shift;
	s32 err;

	sx150x_find_cfg(offset, 1, &reg, &mask, &shift);
	err = sx150x_i2c_read(chip->client, reg, &data);
	if (err >= 0)
		err = (data & mask) != 0 ? 1 : 0;

	return err;
}

static void sx150x_set_oscio(struct sx150x_chip *chip, int val)
{
	sx150x_i2c_write(chip->client,
			chip->dev_cfg->reg_clock,
			(val ? 0x1f : 0x10));
}

static void sx150x_set_io(struct sx150x_chip *chip, unsigned offset, int val)
{
	sx150x_write_cfg(chip,
			offset,
			1,
			chip->dev_cfg->reg_data,
			(val ? 1 : 0));
}

static int sx150x_io_input(struct sx150x_chip *chip, unsigned offset)
{
	return sx150x_write_cfg(chip,
				offset,
				1,
				chip->dev_cfg->reg_dir,
				1);
}

static int sx150x_io_output(struct sx150x_chip *chip, unsigned offset, int val)
{
	int err;

	err = sx150x_write_cfg(chip,
			offset,
			1,
			chip->dev_cfg->reg_data,
			(val ? 1 : 0));
	if (err >= 0)
		err = sx150x_write_cfg(chip,
				offset,
				1,
				chip->dev_cfg->reg_dir,
				0);
	return err;
}

static int sx150x_gpio_get(struct gpio_chip *gc, unsigned offset)
{
	struct sx150x_chip *chip;
	int status = -EINVAL;

	chip = container_of(gc, struct sx150x_chip, gpio_chip);

	if (!offset_is_oscio(chip, offset)) {
		mutex_lock(&chip->lock);
		status = sx150x_get_io(chip, offset);
		mutex_unlock(&chip->lock);
	}

	return status;
}

static void sx150x_gpio_set(struct gpio_chip *gc, unsigned offset, int val)
{
	struct sx150x_chip *chip;

	chip = container_of(gc, struct sx150x_chip, gpio_chip);

	mutex_lock(&chip->lock);
	if (offset_is_oscio(chip, offset))
		sx150x_set_oscio(chip, val);
	else
		sx150x_set_io(chip, offset, val);
	mutex_unlock(&chip->lock);
}

static int sx150x_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
{
	struct sx150x_chip *chip;
	int status = -EINVAL;

	chip = container_of(gc, struct sx150x_chip, gpio_chip);

	if (!offset_is_oscio(chip, offset)) {
		mutex_lock(&chip->lock);
		status = sx150x_io_input(chip, offset);
		mutex_unlock(&chip->lock);
	}
	return status;
}

static int sx150x_gpio_direction_output(struct gpio_chip *gc,
					unsigned offset,
					int val)
{
	struct sx150x_chip *chip;
	int status = 0;

	chip = container_of(gc, struct sx150x_chip, gpio_chip);

	if (!offset_is_oscio(chip, offset)) {
		mutex_lock(&chip->lock);
		status = sx150x_io_output(chip, offset, val);
		mutex_unlock(&chip->lock);
	}
	return status;
}

static int sx150x_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
{
	struct sx150x_chip *chip;

	chip = container_of(gc, struct sx150x_chip, gpio_chip);

	if (offset >= chip->dev_cfg->ngpios)
		return -EINVAL;

	if (chip->irq_base < 0)
		return -EINVAL;

	return chip->irq_base + offset;
}

static void sx150x_irq_mask(unsigned int irq)
{
	struct irq_chip *ic = get_irq_chip(irq);
	struct sx150x_chip *chip;
	unsigned n;

	chip = container_of(ic, struct sx150x_chip, irq_chip);
	n = irq - chip->irq_base;

	sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 1);
	sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense, 0);
}

static void sx150x_irq_unmask(unsigned int irq)
{
	struct irq_chip *ic = get_irq_chip(irq);
	struct sx150x_chip *chip;
	unsigned n;

	chip = container_of(ic, struct sx150x_chip, irq_chip);
	n = irq - chip->irq_base;

	sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 0);
	sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense,
			 chip->irq_sense >> (n * 2));
}

static int sx150x_irq_set_type(unsigned int irq, unsigned int flow_type)
{
	struct irq_chip *ic = get_irq_chip(irq);
	struct sx150x_chip *chip;
	unsigned n, val = 0;

	if (flow_type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
		return -EINVAL;

	chip = container_of(ic, struct sx150x_chip, irq_chip);
	n = irq - chip->irq_base;

	if (flow_type & IRQ_TYPE_EDGE_RISING)
		val |= 0x1;
	if (flow_type & IRQ_TYPE_EDGE_FALLING)
		val |= 0x2;

	chip->irq_sense &= ~(3UL << (n * 2));
	chip->irq_sense |= val << (n * 2);
	chip->irq_set_type_pending |= BIT(n);
	return 0;
}

static irqreturn_t sx150x_irq_thread_fn(int irq, void *dev_id)
{
	struct sx150x_chip *chip = (struct sx150x_chip *)dev_id;
	unsigned nhandled = 0;
	unsigned sub_irq;
	unsigned n;
	s32 err;
	u8 val;
	int i;

	for (i = (chip->dev_cfg->ngpios / 8) - 1; i >= 0; --i) {
		err = sx150x_i2c_read(chip->client,
				      chip->dev_cfg->reg_irq_src - i,
				      &val);
		if (err < 0)
			continue;

		sx150x_i2c_write(chip->client,
				chip->dev_cfg->reg_irq_src - i,
				val);
		for (n = 0; n < 8; ++n) {
			if (val & (1 << n)) {
				sub_irq = chip->irq_base + (i * 8) + n;
				handle_nested_irq(sub_irq);
				++nhandled;
			}
		}
	}

	return (nhandled > 0 ? IRQ_HANDLED : IRQ_NONE);
}

static void sx150x_irq_bus_lock(unsigned int irq)
{
	struct irq_chip *ic = get_irq_chip(irq);
	struct sx150x_chip *chip;

	chip = container_of(ic, struct sx150x_chip, irq_chip);

	mutex_lock(&chip->lock);
}

static void sx150x_irq_bus_sync_unlock(unsigned int irq)
{
	struct irq_chip *ic = get_irq_chip(irq);
	struct sx150x_chip *chip;
	unsigned n;

	chip = container_of(ic, struct sx150x_chip, irq_chip);

	while (chip->irq_set_type_pending) {
		n = __ffs(chip->irq_set_type_pending);
		chip->irq_set_type_pending &= ~BIT(n);
		if (!(irq_to_desc(n + chip->irq_base)->status & IRQ_MASKED))
			sx150x_write_cfg(chip, n, 2,
					chip->dev_cfg->reg_sense,
					chip->irq_sense >> (n * 2));
	}

	mutex_unlock(&chip->lock);
}

static void sx150x_init_chip(struct sx150x_chip *chip,
			struct i2c_client *client,
			kernel_ulong_t driver_data,
			struct sx150x_platform_data *pdata)
{
	mutex_init(&chip->lock);

	chip->client                     = client;
	chip->dev_cfg                    = &sx150x_devices[driver_data];
	chip->gpio_chip.label            = client->name;
	chip->gpio_chip.direction_input  = sx150x_gpio_direction_input;
	chip->gpio_chip.direction_output = sx150x_gpio_direction_output;
	chip->gpio_chip.get              = sx150x_gpio_get;
	chip->gpio_chip.set              = sx150x_gpio_set;
	chip->gpio_chip.to_irq           = sx150x_gpio_to_irq;
	chip->gpio_chip.base             = pdata->gpio_base;
	chip->gpio_chip.can_sleep        = 1;
	chip->gpio_chip.ngpio            = chip->dev_cfg->ngpios;
	if (pdata->oscio_is_gpo)
		++chip->gpio_chip.ngpio;

	chip->irq_chip.name            = client->name;
	chip->irq_chip.mask            = sx150x_irq_mask;
	chip->irq_chip.unmask          = sx150x_irq_unmask;
	chip->irq_chip.set_type        = sx150x_irq_set_type;
	chip->irq_chip.bus_lock        = sx150x_irq_bus_lock;
	chip->irq_chip.bus_sync_unlock = sx150x_irq_bus_sync_unlock;
	chip->irq_summary              = -1;
	chip->irq_base                 = -1;
	chip->irq_sense                = 0;
	chip->irq_set_type_pending     = 0;
}

static int sx150x_init_io(struct sx150x_chip *chip, u8 base, u16 cfg)
{
	int err = 0;
	unsigned n;

	for (n = 0; err >= 0 && n < (chip->dev_cfg->ngpios / 8); ++n)
		err = sx150x_i2c_write(chip->client, base - n, cfg >> (n * 8));
	return err;
}

static int sx150x_init_hw(struct sx150x_chip *chip,
			struct sx150x_platform_data *pdata)
{
	int err = 0;

	err = i2c_smbus_write_word_data(chip->client,
					chip->dev_cfg->reg_reset,
					0x3412);
	if (err < 0)
		return err;

	err = sx150x_i2c_write(chip->client,
			chip->dev_cfg->reg_misc,
			0x01);
	if (err < 0)
		return err;

	err = sx150x_init_io(chip, chip->dev_cfg->reg_pullup,
			pdata->io_pullup_ena);
	if (err < 0)
		return err;

	err = sx150x_init_io(chip, chip->dev_cfg->reg_pulldn,
			pdata->io_pulldn_ena);
	if (err < 0)
		return err;

	err = sx150x_init_io(chip, chip->dev_cfg->reg_drain,
			pdata->io_open_drain_ena);
	if (err < 0)
		return err;

	err = sx150x_init_io(chip, chip->dev_cfg->reg_polarity,
			pdata->io_polarity);
	if (err < 0)
		return err;

	if (pdata->oscio_is_gpo)
		sx150x_set_oscio(chip, 0);

	return err;
}

static int sx150x_install_irq_chip(struct sx150x_chip *chip,
				int irq_summary,
				int irq_base)
{
	int err;
	unsigned n;
	unsigned irq;

	chip->irq_summary = irq_summary;
	chip->irq_base    = irq_base;

	for (n = 0; n < chip->dev_cfg->ngpios; ++n) {
		irq = irq_base + n;
		set_irq_chip_and_handler(irq, &chip->irq_chip, handle_edge_irq);
		set_irq_nested_thread(irq, 1);
#ifdef CONFIG_ARM
		set_irq_flags(irq, IRQF_VALID);
#else
		set_irq_noprobe(irq);
#endif
	}

	err = request_threaded_irq(irq_summary,
				NULL,
				sx150x_irq_thread_fn,
				IRQF_SHARED | IRQF_TRIGGER_FALLING,
				chip->irq_chip.name,
				chip);
	if (err < 0) {
		chip->irq_summary = -1;
		chip->irq_base    = -1;
	}

	return err;
}

static void sx150x_remove_irq_chip(struct sx150x_chip *chip)
{
	unsigned n;
	unsigned irq;

	free_irq(chip->irq_summary, chip);

	for (n = 0; n < chip->dev_cfg->ngpios; ++n) {
		irq = chip->irq_base + n;
		set_irq_handler(irq, NULL);
		set_irq_chip(irq, NULL);
	}
}

static int __devinit sx150x_probe(struct i2c_client *client,
				const struct i2c_device_id *id)
{
	static const u32 i2c_funcs = I2C_FUNC_SMBUS_BYTE_DATA |
				     I2C_FUNC_SMBUS_WRITE_WORD_DATA;
	struct sx150x_platform_data *pdata;
	struct sx150x_chip *chip;
	int rc;

	pdata = client->dev.platform_data;
	if (!pdata)
		return -EINVAL;

	if (!i2c_check_functionality(client->adapter, i2c_funcs))
		return -ENOSYS;

	chip = kzalloc(sizeof(struct sx150x_chip), GFP_KERNEL);
	if (!chip)
		return -ENOMEM;

	sx150x_init_chip(chip, client, id->driver_data, pdata);
	rc = sx150x_init_hw(chip, pdata);
	if (rc < 0)
		goto probe_fail_pre_gpiochip_add;

	rc = gpiochip_add(&chip->gpio_chip);
	if (rc < 0)
		goto probe_fail_pre_gpiochip_add;

	if (pdata->irq_summary >= 0) {
		rc = sx150x_install_irq_chip(chip,
					pdata->irq_summary,
					pdata->irq_base);
		if (rc < 0)
			goto probe_fail_post_gpiochip_add;
	}

	i2c_set_clientdata(client, chip);

	return 0;
probe_fail_post_gpiochip_add:
	WARN_ON(gpiochip_remove(&chip->gpio_chip) < 0);
probe_fail_pre_gpiochip_add:
	kfree(chip);
	return rc;
}

static int __devexit sx150x_remove(struct i2c_client *client)
{
	struct sx150x_chip *chip;
	int rc;

	chip = i2c_get_clientdata(client);
	rc = gpiochip_remove(&chip->gpio_chip);
	if (rc < 0)
		return rc;

	if (chip->irq_summary >= 0)
		sx150x_remove_irq_chip(chip);

	kfree(chip);

	return 0;
}

static struct i2c_driver sx150x_driver = {
	.driver = {
		.name = "sx150x",
		.owner = THIS_MODULE
	},
	.probe    = sx150x_probe,
	.remove   = __devexit_p(sx150x_remove),
	.id_table = sx150x_id,
};

static int __init sx150x_init(void)
{
	return i2c_add_driver(&sx150x_driver);
}
subsys_initcall(sx150x_init);

static void __exit sx150x_exit(void)
{
	return i2c_del_driver(&sx150x_driver);
}
module_exit(sx150x_exit);

MODULE_AUTHOR("Gregory Bean <gbean@codeaurora.org>");
MODULE_DESCRIPTION("Driver for Semtech SX150X I2C GPIO Expanders");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("i2c:sx150x");