summaryrefslogtreecommitdiffstats
path: root/drivers/leds/leds-pca963x.c
blob: 35d56a62f92f343bd34ab04966ebac322bf37c55 (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
/*
 * Copyright 2011 bct electronic GmbH
 * Copyright 2013 Qtechnology/AS
 *
 * Author: Peter Meerwald <p.meerwald@bct-electronic.com>
 * Author: Ricardo Ribalda <ricardo.ribalda@gmail.com>
 *
 * Based on leds-pca955x.c
 *
 * This file is subject to the terms and conditions of version 2 of
 * the GNU General Public License.  See the file COPYING in the main
 * directory of this archive for more details.
 *
 * LED driver for the PCA9633 I2C LED driver (7-bit slave address 0x62)
 * LED driver for the PCA9634 I2C LED driver (7-bit slave address set by hw.)
 *
 * Note that hardware blinking violates the leds infrastructure driver
 * interface since the hardware only supports blinking all LEDs with the
 * same delay_on/delay_off rates.  That is, only the LEDs that are set to
 * blink will actually blink but all LEDs that are set to blink will blink
 * in identical fashion.  The delay_on/delay_off values of the last LED
 * that is set to blink will be used for all of the blinking LEDs.
 * Hardware blinking is disabled by default but can be enabled by setting
 * the 'blink_type' member in the platform_data struct to 'PCA963X_HW_BLINK'
 * or by adding the 'nxp,hw-blink' property to the DTS.
 */

#include <linux/module.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/leds.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/workqueue.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/platform_data/leds-pca963x.h>

/* LED select registers determine the source that drives LED outputs */
#define PCA963X_LED_OFF		0x0	/* LED driver off */
#define PCA963X_LED_ON		0x1	/* LED driver on */
#define PCA963X_LED_PWM		0x2	/* Controlled through PWM */
#define PCA963X_LED_GRP_PWM	0x3	/* Controlled through PWM/GRPPWM */

#define PCA963X_MODE2_DMBLNK	0x20	/* Enable blinking */

#define PCA963X_MODE1		0x00
#define PCA963X_MODE2		0x01
#define PCA963X_PWM_BASE	0x02

enum pca963x_type {
	pca9633,
	pca9634,
};

struct pca963x_chipdef {
	u8			grppwm;
	u8			grpfreq;
	u8			ledout_base;
	int			n_leds;
};

static struct pca963x_chipdef pca963x_chipdefs[] = {
	[pca9633] = {
		.grppwm		= 0x6,
		.grpfreq	= 0x7,
		.ledout_base	= 0x8,
		.n_leds		= 4,
	},
	[pca9634] = {
		.grppwm		= 0xa,
		.grpfreq	= 0xb,
		.ledout_base	= 0xc,
		.n_leds		= 8,
	},
};

/* Total blink period in milliseconds */
#define PCA963X_BLINK_PERIOD_MIN	42
#define PCA963X_BLINK_PERIOD_MAX	10667

static const struct i2c_device_id pca963x_id[] = {
	{ "pca9632", pca9633 },
	{ "pca9633", pca9633 },
	{ "pca9634", pca9634 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, pca963x_id);

enum pca963x_cmd {
	BRIGHTNESS_SET,
	BLINK_SET,
};

struct pca963x_led;

struct pca963x {
	struct pca963x_chipdef *chipdef;
	struct mutex mutex;
	struct i2c_client *client;
	struct pca963x_led *leds;
};

struct pca963x_led {
	struct pca963x *chip;
	struct work_struct work;
	enum led_brightness brightness;
	struct led_classdev led_cdev;
	int led_num; /* 0 .. 7 potentially */
	enum pca963x_cmd cmd;
	char name[32];
	u8 gdc;
	u8 gfrq;
};

static void pca963x_brightness_work(struct pca963x_led *pca963x)
{
	u8 ledout_addr = pca963x->chip->chipdef->ledout_base
		+ (pca963x->led_num / 4);
	u8 ledout;
	int shift = 2 * (pca963x->led_num % 4);
	u8 mask = 0x3 << shift;

	mutex_lock(&pca963x->chip->mutex);
	ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
	switch (pca963x->brightness) {
	case LED_FULL:
		i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
			(ledout & ~mask) | (PCA963X_LED_ON << shift));
		break;
	case LED_OFF:
		i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
			ledout & ~mask);
		break;
	default:
		i2c_smbus_write_byte_data(pca963x->chip->client,
			PCA963X_PWM_BASE + pca963x->led_num,
			pca963x->brightness);
		i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
			(ledout & ~mask) | (PCA963X_LED_PWM << shift));
		break;
	}
	mutex_unlock(&pca963x->chip->mutex);
}

static void pca963x_blink_work(struct pca963x_led *pca963x)
{
	u8 ledout_addr = pca963x->chip->chipdef->ledout_base +
		(pca963x->led_num / 4);
	u8 ledout;
	u8 mode2 = i2c_smbus_read_byte_data(pca963x->chip->client,
							PCA963X_MODE2);
	int shift = 2 * (pca963x->led_num % 4);
	u8 mask = 0x3 << shift;

	i2c_smbus_write_byte_data(pca963x->chip->client,
			pca963x->chip->chipdef->grppwm,	pca963x->gdc);

	i2c_smbus_write_byte_data(pca963x->chip->client,
			pca963x->chip->chipdef->grpfreq, pca963x->gfrq);

	if (!(mode2 & PCA963X_MODE2_DMBLNK))
		i2c_smbus_write_byte_data(pca963x->chip->client, PCA963X_MODE2,
			mode2 | PCA963X_MODE2_DMBLNK);

	mutex_lock(&pca963x->chip->mutex);
	ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
	if ((ledout & mask) != (PCA963X_LED_GRP_PWM << shift))
		i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
			(ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift));
	mutex_unlock(&pca963x->chip->mutex);
}

static void pca963x_work(struct work_struct *work)
{
	struct pca963x_led *pca963x = container_of(work,
		struct pca963x_led, work);

	switch (pca963x->cmd) {
	case BRIGHTNESS_SET:
		pca963x_brightness_work(pca963x);
		break;
	case BLINK_SET:
		pca963x_blink_work(pca963x);
		break;
	}
}

static void pca963x_led_set(struct led_classdev *led_cdev,
	enum led_brightness value)
{
	struct pca963x_led *pca963x;

	pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);

	pca963x->cmd = BRIGHTNESS_SET;
	pca963x->brightness = value;

	/*
	 * Must use workqueue for the actual I/O since I2C operations
	 * can sleep.
	 */
	schedule_work(&pca963x->work);
}

static int pca963x_blink_set(struct led_classdev *led_cdev,
		unsigned long *delay_on, unsigned long *delay_off)
{
	struct pca963x_led *pca963x;
	unsigned long time_on, time_off, period;
	u8 gdc, gfrq;

	pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);

	time_on = *delay_on;
	time_off = *delay_off;

	/* If both zero, pick reasonable defaults of 500ms each */
	if (!time_on && !time_off) {
		time_on = 500;
		time_off = 500;
	}

	period = time_on + time_off;

	/* If period not supported by hardware, default to someting sane. */
	if ((period < PCA963X_BLINK_PERIOD_MIN) ||
	    (period > PCA963X_BLINK_PERIOD_MAX)) {
		time_on = 500;
		time_off = 500;
		period = time_on + time_off;
	}

	/*
	 * From manual: duty cycle = (GDC / 256) ->
	 *	(time_on / period) = (GDC / 256) ->
	 *		GDC = ((time_on * 256) / period)
	 */
	gdc = (time_on * 256) / period;

	/*
	 * From manual: period = ((GFRQ + 1) / 24) in seconds.
	 * So, period (in ms) = (((GFRQ + 1) / 24) * 1000) ->
	 *		GFRQ = ((period * 24 / 1000) - 1)
	 */
	gfrq = (period * 24 / 1000) - 1;

	pca963x->cmd = BLINK_SET;
	pca963x->gdc = gdc;
	pca963x->gfrq = gfrq;

	/*
	 * Must use workqueue for the actual I/O since I2C operations
	 * can sleep.
	 */
	schedule_work(&pca963x->work);

	*delay_on = time_on;
	*delay_off = time_off;

	return 0;
}

#if IS_ENABLED(CONFIG_OF)
static struct pca963x_platform_data *
pca963x_dt_init(struct i2c_client *client, struct pca963x_chipdef *chip)
{
	struct device_node *np = client->dev.of_node, *child;
	struct pca963x_platform_data *pdata;
	struct led_info *pca963x_leds;
	int count;

	count = of_get_child_count(np);
	if (!count || count > chip->n_leds)
		return ERR_PTR(-ENODEV);

	pca963x_leds = devm_kzalloc(&client->dev,
			sizeof(struct led_info) * chip->n_leds, GFP_KERNEL);
	if (!pca963x_leds)
		return ERR_PTR(-ENOMEM);

	for_each_child_of_node(np, child) {
		struct led_info led;
		u32 reg;
		int res;

		led.name =
			of_get_property(child, "label", NULL) ? : child->name;
		led.default_trigger =
			of_get_property(child, "linux,default-trigger", NULL);
		res = of_property_read_u32(child, "reg", &reg);
		if (res != 0)
			continue;
		pca963x_leds[reg] = led;
	}
	pdata = devm_kzalloc(&client->dev,
			     sizeof(struct pca963x_platform_data), GFP_KERNEL);
	if (!pdata)
		return ERR_PTR(-ENOMEM);

	pdata->leds.leds = pca963x_leds;
	pdata->leds.num_leds = count;

	/* default to open-drain unless totem pole (push-pull) is specified */
	if (of_property_read_bool(np, "nxp,totem-pole"))
		pdata->outdrv = PCA963X_TOTEM_POLE;
	else
		pdata->outdrv = PCA963X_OPEN_DRAIN;

	/* default to software blinking unless hardware blinking is specified */
	if (of_property_read_bool(np, "nxp,hw-blink"))
		pdata->blink_type = PCA963X_HW_BLINK;
	else
		pdata->blink_type = PCA963X_SW_BLINK;

	return pdata;
}

static const struct of_device_id of_pca963x_match[] = {
	{ .compatible = "nxp,pca9632", },
	{ .compatible = "nxp,pca9633", },
	{ .compatible = "nxp,pca9634", },
	{},
};
#else
static struct pca963x_platform_data *
pca963x_dt_init(struct i2c_client *client, struct pca963x_chipdef *chip)
{
	return ERR_PTR(-ENODEV);
}
#endif

static int pca963x_probe(struct i2c_client *client,
					const struct i2c_device_id *id)
{
	struct pca963x *pca963x_chip;
	struct pca963x_led *pca963x;
	struct pca963x_platform_data *pdata;
	struct pca963x_chipdef *chip;
	int i, err;

	chip = &pca963x_chipdefs[id->driver_data];
	pdata = dev_get_platdata(&client->dev);

	if (!pdata) {
		pdata = pca963x_dt_init(client, chip);
		if (IS_ERR(pdata)) {
			dev_warn(&client->dev, "could not parse configuration\n");
			pdata = NULL;
		}
	}

	if (pdata && (pdata->leds.num_leds < 1 ||
				 pdata->leds.num_leds > chip->n_leds)) {
		dev_err(&client->dev, "board info must claim 1-%d LEDs",
								chip->n_leds);
		return -EINVAL;
	}

	pca963x_chip = devm_kzalloc(&client->dev, sizeof(*pca963x_chip),
								GFP_KERNEL);
	if (!pca963x_chip)
		return -ENOMEM;
	pca963x = devm_kzalloc(&client->dev, chip->n_leds * sizeof(*pca963x),
								GFP_KERNEL);
	if (!pca963x)
		return -ENOMEM;

	i2c_set_clientdata(client, pca963x_chip);

	mutex_init(&pca963x_chip->mutex);
	pca963x_chip->chipdef = chip;
	pca963x_chip->client = client;
	pca963x_chip->leds = pca963x;

	/* Turn off LEDs by default*/
	i2c_smbus_write_byte_data(client, chip->ledout_base, 0x00);
	if (chip->n_leds > 4)
		i2c_smbus_write_byte_data(client, chip->ledout_base + 1, 0x00);

	for (i = 0; i < chip->n_leds; i++) {
		pca963x[i].led_num = i;
		pca963x[i].chip = pca963x_chip;

		/* Platform data can specify LED names and default triggers */
		if (pdata && i < pdata->leds.num_leds) {
			if (pdata->leds.leds[i].name)
				snprintf(pca963x[i].name,
					 sizeof(pca963x[i].name), "pca963x:%s",
					 pdata->leds.leds[i].name);
			if (pdata->leds.leds[i].default_trigger)
				pca963x[i].led_cdev.default_trigger =
					pdata->leds.leds[i].default_trigger;
		}
		if (!pdata || i >= pdata->leds.num_leds ||
						!pdata->leds.leds[i].name)
			snprintf(pca963x[i].name, sizeof(pca963x[i].name),
				 "pca963x:%d:%.2x:%d", client->adapter->nr,
				 client->addr, i);

		pca963x[i].led_cdev.name = pca963x[i].name;
		pca963x[i].led_cdev.brightness_set = pca963x_led_set;

		if (pdata && pdata->blink_type == PCA963X_HW_BLINK)
			pca963x[i].led_cdev.blink_set = pca963x_blink_set;

		INIT_WORK(&pca963x[i].work, pca963x_work);

		err = led_classdev_register(&client->dev, &pca963x[i].led_cdev);
		if (err < 0)
			goto exit;
	}

	/* Disable LED all-call address and set normal mode */
	i2c_smbus_write_byte_data(client, PCA963X_MODE1, 0x00);

	/* Configure output: open-drain or totem pole (push-pull) */
	if (pdata && pdata->outdrv == PCA963X_OPEN_DRAIN)
		i2c_smbus_write_byte_data(client, PCA963X_MODE2, 0x01);

	return 0;

exit:
	while (i--) {
		led_classdev_unregister(&pca963x[i].led_cdev);
		cancel_work_sync(&pca963x[i].work);
	}

	return err;
}

static int pca963x_remove(struct i2c_client *client)
{
	struct pca963x *pca963x = i2c_get_clientdata(client);
	int i;

	for (i = 0; i < pca963x->chipdef->n_leds; i++) {
		led_classdev_unregister(&pca963x->leds[i].led_cdev);
		cancel_work_sync(&pca963x->leds[i].work);
	}

	return 0;
}

static struct i2c_driver pca963x_driver = {
	.driver = {
		.name	= "leds-pca963x",
		.owner	= THIS_MODULE,
		.of_match_table = of_match_ptr(of_pca963x_match),
	},
	.probe	= pca963x_probe,
	.remove	= pca963x_remove,
	.id_table = pca963x_id,
};

module_i2c_driver(pca963x_driver);

MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>");
MODULE_DESCRIPTION("PCA963X LED driver");
MODULE_LICENSE("GPL v2");