aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/gpio/pca953x.c
blob: a2b12aa1f2b93920b55b255efbf60ad037a4c0d0 (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
/*
 *  pca953x.c - 4/8/16 bit I/O ports
 *
 *  Copyright (C) 2005 Ben Gardner <bgardner@wabtec.com>
 *  Copyright (C) 2007 Marvell International Ltd.
 *
 *  Derived from drivers/i2c/chips/pca9539.c
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; version 2 of the License.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/i2c.h>
#include <linux/i2c/pca953x.h>
#include <linux/slab.h>
#ifdef CONFIG_OF_GPIO
#include <linux/of_platform.h>
#include <linux/of_gpio.h>
#endif

#define PCA953X_INPUT          0
#define PCA953X_OUTPUT         1
#define PCA953X_INVERT         2
#define PCA953X_DIRECTION      3

#define PCA953X_GPIOS	       0x00FF
#define PCA953X_INT	       0x0100

static const struct i2c_device_id pca953x_id[] = {
	{ "pca9534", 8  | PCA953X_INT, },
	{ "pca9535", 16 | PCA953X_INT, },
	{ "pca9536", 4, },
	{ "pca9537", 4  | PCA953X_INT, },
	{ "pca9538", 8  | PCA953X_INT, },
	{ "pca9539", 16 | PCA953X_INT, },
	{ "pca9554", 8  | PCA953X_INT, },
	{ "pca9555", 16 | PCA953X_INT, },
	{ "pca9556", 8, },
	{ "pca9557", 8, },

	{ "max7310", 8, },
	{ "max7312", 16 | PCA953X_INT, },
	{ "max7313", 16 | PCA953X_INT, },
	{ "max7315", 8  | PCA953X_INT, },
	{ "pca6107", 8  | PCA953X_INT, },
	{ "tca6408", 8  | PCA953X_INT, },
	{ "tca6416", 16 | PCA953X_INT, },
	/* NYET:  { "tca6424", 24, }, */
	{ }
};
MODULE_DEVICE_TABLE(i2c, pca953x_id);

struct pca953x_chip {
	unsigned gpio_start;
	uint16_t reg_output;
	uint16_t reg_direction;

#ifdef CONFIG_GPIO_PCA953X_IRQ
	struct mutex irq_lock;
	uint16_t irq_mask;
	uint16_t irq_stat;
	uint16_t irq_trig_raise;
	uint16_t irq_trig_fall;
	int	 irq_base;
#endif

	struct i2c_client *client;
	struct pca953x_platform_data *dyn_pdata;
	struct gpio_chip gpio_chip;
	const char *const *names;
};

static int pca953x_write_reg(struct pca953x_chip *chip, int reg, uint16_t val)
{
	int ret;

	if (chip->gpio_chip.ngpio <= 8)
		ret = i2c_smbus_write_byte_data(chip->client, reg, val);
	else
		ret = i2c_smbus_write_word_data(chip->client, reg << 1, val);

	if (ret < 0) {
		dev_err(&chip->client->dev, "failed writing register\n");
		return ret;
	}

	return 0;
}

static int pca953x_read_reg(struct pca953x_chip *chip, int reg, uint16_t *val)
{
	int ret;

	if (chip->gpio_chip.ngpio <= 8)
		ret = i2c_smbus_read_byte_data(chip->client, reg);
	else
		ret = i2c_smbus_read_word_data(chip->client, reg << 1);

	if (ret < 0) {
		dev_err(&chip->client->dev, "failed reading register\n");
		return ret;
	}

	*val = (uint16_t)ret;
	return 0;
}

static int pca953x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
{
	struct pca953x_chip *chip;
	uint16_t reg_val;
	int ret;

	chip = container_of(gc, struct pca953x_chip, gpio_chip);

	reg_val = chip->reg_direction | (1u << off);
	ret = pca953x_write_reg(chip, PCA953X_DIRECTION, reg_val);
	if (ret)
		return ret;

	chip->reg_direction = reg_val;
	return 0;
}

static int pca953x_gpio_direction_output(struct gpio_chip *gc,
		unsigned off, int val)
{
	struct pca953x_chip *chip;
	uint16_t reg_val;
	int ret;

	chip = container_of(gc, struct pca953x_chip, gpio_chip);

	/* set output level */
	if (val)
		reg_val = chip->reg_output | (1u << off);
	else
		reg_val = chip->reg_output & ~(1u << off);

	ret = pca953x_write_reg(chip, PCA953X_OUTPUT, reg_val);
	if (ret)
		return ret;

	chip->reg_output = reg_val;

	/* then direction */
	reg_val = chip->reg_direction & ~(1u << off);
	ret = pca953x_write_reg(chip, PCA953X_DIRECTION, reg_val);
	if (ret)
		return ret;

	chip->reg_direction = reg_val;
	return 0;
}

static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off)
{
	struct pca953x_chip *chip;
	uint16_t reg_val;
	int ret;

	chip = container_of(gc, struct pca953x_chip, gpio_chip);

	ret = pca953x_read_reg(chip, PCA953X_INPUT, &reg_val);
	if (ret < 0) {
		/* NOTE:  diagnostic already emitted; that's all we should
		 * do unless gpio_*_value_cansleep() calls become different
		 * from their nonsleeping siblings (and report faults).
		 */
		return 0;
	}

	return (reg_val & (1u << off)) ? 1 : 0;
}

static void pca953x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
{
	struct pca953x_chip *chip;
	uint16_t reg_val;
	int ret;

	chip = container_of(gc, struct pca953x_chip, gpio_chip);

	if (val)
		reg_val = chip->reg_output | (1u << off);
	else
		reg_val = chip->reg_output & ~(1u << off);

	ret = pca953x_write_reg(chip, PCA953X_OUTPUT, reg_val);
	if (ret)
		return;

	chip->reg_output = reg_val;
}

static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios)
{
	struct gpio_chip *gc;

	gc = &chip->gpio_chip;

	gc->direction_input  = pca953x_gpio_direction_input;
	gc->direction_output = pca953x_gpio_direction_output;
	gc->get = pca953x_gpio_get_value;
	gc->set = pca953x_gpio_set_value;
	gc->can_sleep = 1;

	gc->base = chip->gpio_start;
	gc->ngpio = gpios;
	gc->label = chip->client->name;
	gc->dev = &chip->client->dev;
	gc->owner = THIS_MODULE;
	gc->names = chip->names;
}

#ifdef CONFIG_GPIO_PCA953X_IRQ
static int pca953x_gpio_to_irq(struct gpio_chip *gc, unsigned off)
{
	struct pca953x_chip *chip;

	chip = container_of(gc, struct pca953x_chip, gpio_chip);
	return chip->irq_base + off;
}

static void pca953x_irq_mask(unsigned int irq)
{
	struct pca953x_chip *chip = get_irq_chip_data(irq);

	chip->irq_mask &= ~(1 << (irq - chip->irq_base));
}

static void pca953x_irq_unmask(unsigned int irq)
{
	struct pca953x_chip *chip = get_irq_chip_data(irq);

	chip->irq_mask |= 1 << (irq - chip->irq_base);
}

static void pca953x_irq_bus_lock(unsigned int irq)
{
	struct pca953x_chip *chip = get_irq_chip_data(irq);

	mutex_lock(&chip->irq_lock);
}

static void pca953x_irq_bus_sync_unlock(unsigned int irq)
{
	struct pca953x_chip *chip = get_irq_chip_data(irq);
	uint16_t new_irqs;
	uint16_t level;

	/* Look for any newly setup interrupt */
	new_irqs = chip->irq_trig_fall | chip->irq_trig_raise;
	new_irqs &= ~chip->reg_direction;

	while (new_irqs) {
		level = __ffs(new_irqs);
		pca953x_gpio_direction_input(&chip->gpio_chip, level);
		new_irqs &= ~(1 << level);
	}

	mutex_unlock(&chip->irq_lock);
}

static int pca953x_irq_set_type(unsigned int irq, unsigned int type)
{
	struct pca953x_chip *chip = get_irq_chip_data(irq);
	uint16_t level = irq - chip->irq_base;
	uint16_t mask = 1 << level;

	if (!(type & IRQ_TYPE_EDGE_BOTH)) {
		dev_err(&chip->client->dev, "irq %d: unsupported type %d\n",
			irq, type);
		return -EINVAL;
	}

	if (type & IRQ_TYPE_EDGE_FALLING)
		chip->irq_trig_fall |= mask;
	else
		chip->irq_trig_fall &= ~mask;

	if (type & IRQ_TYPE_EDGE_RISING)
		chip->irq_trig_raise |= mask;
	else
		chip->irq_trig_raise &= ~mask;

	return 0;
}

static struct irq_chip pca953x_irq_chip = {
	.name			= "pca953x",
	.mask			= pca953x_irq_mask,
	.unmask			= pca953x_irq_unmask,
	.bus_lock		= pca953x_irq_bus_lock,
	.bus_sync_unlock	= pca953x_irq_bus_sync_unlock,
	.set_type		= pca953x_irq_set_type,
};

static uint16_t pca953x_irq_pending(struct pca953x_chip *chip)
{
	uint16_t cur_stat;
	uint16_t old_stat;
	uint16_t pending;
	uint16_t trigger;
	int ret;

	ret = pca953x_read_reg(chip, PCA953X_INPUT, &cur_stat);
	if (ret)
		return 0;

	/* Remove output pins from the equation */
	cur_stat &= chip->reg_direction;

	old_stat = chip->irq_stat;
	trigger = (cur_stat ^ old_stat) & chip->irq_mask;

	if (!trigger)
		return 0;

	chip->irq_stat = cur_stat;

	pending = (old_stat & chip->irq_trig_fall) |
		  (cur_stat & chip->irq_trig_raise);
	pending &= trigger;

	return pending;
}

static irqreturn_t pca953x_irq_handler(int irq, void *devid)
{
	struct pca953x_chip *chip = devid;
	uint16_t pending;
	uint16_t level;

	pending = pca953x_irq_pending(chip);

	if (!pending)
		return IRQ_HANDLED;

	do {
		level = __ffs(pending);
		handle_nested_irq(level + chip->irq_base);

		pending &= ~(1 << level);
	} while (pending);

	return IRQ_HANDLED;
}

static int pca953x_irq_setup(struct pca953x_chip *chip,
			     const struct i2c_device_id *id)
{
	struct i2c_client *client = chip->client;
	struct pca953x_platform_data *pdata = client->dev.platform_data;
	int ret;

	if (pdata->irq_base && (id->driver_data & PCA953X_INT)) {
		int lvl;

		ret = pca953x_read_reg(chip, PCA953X_INPUT,
				       &chip->irq_stat);
		if (ret)
			goto out_failed;

		/*
		 * There is no way to know which GPIO line generated the
		 * interrupt.  We have to rely on the previous read for
		 * this purpose.
		 */
		chip->irq_stat &= chip->reg_direction;
		chip->irq_base = pdata->irq_base;
		mutex_init(&chip->irq_lock);

		for (lvl = 0; lvl < chip->gpio_chip.ngpio; lvl++) {
			int irq = lvl + chip->irq_base;

			set_irq_chip_data(irq, chip);
			set_irq_chip_and_handler(irq, &pca953x_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
		}

		ret = request_threaded_irq(client->irq,
					   NULL,
					   pca953x_irq_handler,
					   IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
					   dev_name(&client->dev), chip);
		if (ret) {
			dev_err(&client->dev, "failed to request irq %d\n",
				client->irq);
			goto out_failed;
		}

		chip->gpio_chip.to_irq = pca953x_gpio_to_irq;
	}

	return 0;

out_failed:
	chip->irq_base = 0;
	return ret;
}

static void pca953x_irq_teardown(struct pca953x_chip *chip)
{
	if (chip->irq_base)
		free_irq(chip->client->irq, chip);
}
#else /* CONFIG_GPIO_PCA953X_IRQ */
static int pca953x_irq_setup(struct pca953x_chip *chip,
			     const struct i2c_device_id *id)
{
	struct i2c_client *client = chip->client;
	struct pca953x_platform_data *pdata = client->dev.platform_data;

	if (pdata->irq_base && (id->driver_data & PCA953X_INT))
		dev_warn(&client->dev, "interrupt support not compiled in\n");

	return 0;
}

static void pca953x_irq_teardown(struct pca953x_chip *chip)
{
}
#endif

/*
 * Handlers for alternative sources of platform_data
 */
#ifdef CONFIG_OF_GPIO
/*
 * Translate OpenFirmware node properties into platform_data
 */
static struct pca953x_platform_data *
pca953x_get_alt_pdata(struct i2c_client *client)
{
	struct pca953x_platform_data *pdata;
	struct device_node *node;
	const uint16_t *val;

	node = client->dev.of_node;
	if (node == NULL)
		return NULL;

	pdata = kzalloc(sizeof(struct pca953x_platform_data), GFP_KERNEL);
	if (pdata == NULL) {
		dev_err(&client->dev, "Unable to allocate platform_data\n");
		return NULL;
	}

	pdata->gpio_base = -1;
	val = of_get_property(node, "linux,gpio-base", NULL);
	if (val) {
		if (*val < 0)
			dev_warn(&client->dev,
				 "invalid gpio-base in device tree\n");
		else
			pdata->gpio_base = *val;
	}

	val = of_get_property(node, "polarity", NULL);
	if (val)
		pdata->invert = *val;

	return pdata;
}
#else
static struct pca953x_platform_data *
pca953x_get_alt_pdata(struct i2c_client *client)
{
	return NULL;
}
#endif

static int __devinit pca953x_probe(struct i2c_client *client,
				   const struct i2c_device_id *id)
{
	struct pca953x_platform_data *pdata;
	struct pca953x_chip *chip;
	int ret;

	chip = kzalloc(sizeof(struct pca953x_chip), GFP_KERNEL);
	if (chip == NULL)
		return -ENOMEM;

	pdata = client->dev.platform_data;
	if (pdata == NULL) {
		pdata = pca953x_get_alt_pdata(client);
		/*
		 * Unlike normal platform_data, this is allocated
		 * dynamically and must be freed in the driver
		 */
		chip->dyn_pdata = pdata;
	}

	if (pdata == NULL) {
		dev_dbg(&client->dev, "no platform data\n");
		ret = -EINVAL;
		goto out_failed;
	}

	chip->client = client;

	chip->gpio_start = pdata->gpio_base;

	chip->names = pdata->names;

	/* initialize cached registers from their original values.
	 * we can't share this chip with another i2c master.
	 */
	pca953x_setup_gpio(chip, id->driver_data & PCA953X_GPIOS);

	ret = pca953x_read_reg(chip, PCA953X_OUTPUT, &chip->reg_output);
	if (ret)
		goto out_failed;

	ret = pca953x_read_reg(chip, PCA953X_DIRECTION, &chip->reg_direction);
	if (ret)
		goto out_failed;

	/* set platform specific polarity inversion */
	ret = pca953x_write_reg(chip, PCA953X_INVERT, pdata->invert);
	if (ret)
		goto out_failed;

	ret = pca953x_irq_setup(chip, id);
	if (ret)
		goto out_failed;

	ret = gpiochip_add(&chip->gpio_chip);
	if (ret)
		goto out_failed;

	if (pdata->setup) {
		ret = pdata->setup(client, chip->gpio_chip.base,
				chip->gpio_chip.ngpio, pdata->context);
		if (ret < 0)
			dev_warn(&client->dev, "setup failed, %d\n", ret);
	}

	i2c_set_clientdata(client, chip);
	return 0;

out_failed:
	pca953x_irq_teardown(chip);
	kfree(chip->dyn_pdata);
	kfree(chip);
	return ret;
}

static int pca953x_remove(struct i2c_client *client)
{
	struct pca953x_platform_data *pdata = client->dev.platform_data;
	struct pca953x_chip *chip = i2c_get_clientdata(client);
	int ret = 0;

	if (pdata->teardown) {
		ret = pdata->teardown(client, chip->gpio_chip.base,
				chip->gpio_chip.ngpio, pdata->context);
		if (ret < 0) {
			dev_err(&client->dev, "%s failed, %d\n",
					"teardown", ret);
			return ret;
		}
	}

	ret = gpiochip_remove(&chip->gpio_chip);
	if (ret) {
		dev_err(&client->dev, "%s failed, %d\n",
				"gpiochip_remove()", ret);
		return ret;
	}

	pca953x_irq_teardown(chip);
	kfree(chip->dyn_pdata);
	kfree(chip);
	return 0;
}

static struct i2c_driver pca953x_driver = {
	.driver = {
		.name	= "pca953x",
	},
	.probe		= pca953x_probe,
	.remove		= pca953x_remove,
	.id_table	= pca953x_id,
};

static int __init pca953x_init(void)
{
	return i2c_add_driver(&pca953x_driver);
}
/* register after i2c postcore initcall and before
 * subsys initcalls that may rely on these GPIOs
 */
subsys_initcall(pca953x_init);

static void __exit pca953x_exit(void)
{
	i2c_del_driver(&pca953x_driver);
}
module_exit(pca953x_exit);

MODULE_AUTHOR("eric miao <eric.miao@marvell.com>");
MODULE_DESCRIPTION("GPIO expander driver for PCA953x");
MODULE_LICENSE("GPL");