xref: /openbmc/linux/drivers/leds/leds-pca963x.c (revision 42bc47b3)
1 /*
2  * Copyright 2011 bct electronic GmbH
3  * Copyright 2013 Qtechnology/AS
4  *
5  * Author: Peter Meerwald <p.meerwald@bct-electronic.com>
6  * Author: Ricardo Ribalda <ricardo.ribalda@gmail.com>
7  *
8  * Based on leds-pca955x.c
9  *
10  * This file is subject to the terms and conditions of version 2 of
11  * the GNU General Public License.  See the file COPYING in the main
12  * directory of this archive for more details.
13  *
14  * LED driver for the PCA9633 I2C LED driver (7-bit slave address 0x62)
15  * LED driver for the PCA9634/5 I2C LED driver (7-bit slave address set by hw.)
16  *
17  * Note that hardware blinking violates the leds infrastructure driver
18  * interface since the hardware only supports blinking all LEDs with the
19  * same delay_on/delay_off rates.  That is, only the LEDs that are set to
20  * blink will actually blink but all LEDs that are set to blink will blink
21  * in identical fashion.  The delay_on/delay_off values of the last LED
22  * that is set to blink will be used for all of the blinking LEDs.
23  * Hardware blinking is disabled by default but can be enabled by setting
24  * the 'blink_type' member in the platform_data struct to 'PCA963X_HW_BLINK'
25  * or by adding the 'nxp,hw-blink' property to the DTS.
26  */
27 
28 #include <linux/acpi.h>
29 #include <linux/module.h>
30 #include <linux/delay.h>
31 #include <linux/string.h>
32 #include <linux/ctype.h>
33 #include <linux/leds.h>
34 #include <linux/err.h>
35 #include <linux/i2c.h>
36 #include <linux/slab.h>
37 #include <linux/of.h>
38 #include <linux/platform_data/leds-pca963x.h>
39 
40 /* LED select registers determine the source that drives LED outputs */
41 #define PCA963X_LED_OFF		0x0	/* LED driver off */
42 #define PCA963X_LED_ON		0x1	/* LED driver on */
43 #define PCA963X_LED_PWM		0x2	/* Controlled through PWM */
44 #define PCA963X_LED_GRP_PWM	0x3	/* Controlled through PWM/GRPPWM */
45 
46 #define PCA963X_MODE2_DMBLNK	0x20	/* Enable blinking */
47 
48 #define PCA963X_MODE1		0x00
49 #define PCA963X_MODE2		0x01
50 #define PCA963X_PWM_BASE	0x02
51 
52 enum pca963x_type {
53 	pca9633,
54 	pca9634,
55 	pca9635,
56 };
57 
58 struct pca963x_chipdef {
59 	u8			grppwm;
60 	u8			grpfreq;
61 	u8			ledout_base;
62 	int			n_leds;
63 	unsigned int		scaling;
64 };
65 
66 static struct pca963x_chipdef pca963x_chipdefs[] = {
67 	[pca9633] = {
68 		.grppwm		= 0x6,
69 		.grpfreq	= 0x7,
70 		.ledout_base	= 0x8,
71 		.n_leds		= 4,
72 	},
73 	[pca9634] = {
74 		.grppwm		= 0xa,
75 		.grpfreq	= 0xb,
76 		.ledout_base	= 0xc,
77 		.n_leds		= 8,
78 	},
79 	[pca9635] = {
80 		.grppwm		= 0x12,
81 		.grpfreq	= 0x13,
82 		.ledout_base	= 0x14,
83 		.n_leds		= 16,
84 	},
85 };
86 
87 /* Total blink period in milliseconds */
88 #define PCA963X_BLINK_PERIOD_MIN	42
89 #define PCA963X_BLINK_PERIOD_MAX	10667
90 
91 static const struct i2c_device_id pca963x_id[] = {
92 	{ "pca9632", pca9633 },
93 	{ "pca9633", pca9633 },
94 	{ "pca9634", pca9634 },
95 	{ "pca9635", pca9635 },
96 	{ }
97 };
98 MODULE_DEVICE_TABLE(i2c, pca963x_id);
99 
100 static const struct acpi_device_id pca963x_acpi_ids[] = {
101 	{ "PCA9632", pca9633 },
102 	{ "PCA9633", pca9633 },
103 	{ "PCA9634", pca9634 },
104 	{ "PCA9635", pca9635 },
105 	{ }
106 };
107 MODULE_DEVICE_TABLE(acpi, pca963x_acpi_ids);
108 
109 struct pca963x_led;
110 
111 struct pca963x {
112 	struct pca963x_chipdef *chipdef;
113 	struct mutex mutex;
114 	struct i2c_client *client;
115 	struct pca963x_led *leds;
116 	unsigned long leds_on;
117 };
118 
119 struct pca963x_led {
120 	struct pca963x *chip;
121 	struct led_classdev led_cdev;
122 	int led_num; /* 0 .. 15 potentially */
123 	char name[32];
124 	u8 gdc;
125 	u8 gfrq;
126 };
127 
128 static int pca963x_brightness(struct pca963x_led *pca963x,
129 			       enum led_brightness brightness)
130 {
131 	u8 ledout_addr = pca963x->chip->chipdef->ledout_base
132 		+ (pca963x->led_num / 4);
133 	u8 ledout;
134 	int shift = 2 * (pca963x->led_num % 4);
135 	u8 mask = 0x3 << shift;
136 	int ret;
137 
138 	ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
139 	switch (brightness) {
140 	case LED_FULL:
141 		ret = i2c_smbus_write_byte_data(pca963x->chip->client,
142 			ledout_addr,
143 			(ledout & ~mask) | (PCA963X_LED_ON << shift));
144 		break;
145 	case LED_OFF:
146 		ret = i2c_smbus_write_byte_data(pca963x->chip->client,
147 			ledout_addr, ledout & ~mask);
148 		break;
149 	default:
150 		ret = i2c_smbus_write_byte_data(pca963x->chip->client,
151 			PCA963X_PWM_BASE + pca963x->led_num,
152 			brightness);
153 		if (ret < 0)
154 			return ret;
155 		ret = i2c_smbus_write_byte_data(pca963x->chip->client,
156 			ledout_addr,
157 			(ledout & ~mask) | (PCA963X_LED_PWM << shift));
158 		break;
159 	}
160 
161 	return ret;
162 }
163 
164 static void pca963x_blink(struct pca963x_led *pca963x)
165 {
166 	u8 ledout_addr = pca963x->chip->chipdef->ledout_base +
167 		(pca963x->led_num / 4);
168 	u8 ledout;
169 	u8 mode2 = i2c_smbus_read_byte_data(pca963x->chip->client,
170 							PCA963X_MODE2);
171 	int shift = 2 * (pca963x->led_num % 4);
172 	u8 mask = 0x3 << shift;
173 
174 	i2c_smbus_write_byte_data(pca963x->chip->client,
175 			pca963x->chip->chipdef->grppwm,	pca963x->gdc);
176 
177 	i2c_smbus_write_byte_data(pca963x->chip->client,
178 			pca963x->chip->chipdef->grpfreq, pca963x->gfrq);
179 
180 	if (!(mode2 & PCA963X_MODE2_DMBLNK))
181 		i2c_smbus_write_byte_data(pca963x->chip->client, PCA963X_MODE2,
182 			mode2 | PCA963X_MODE2_DMBLNK);
183 
184 	mutex_lock(&pca963x->chip->mutex);
185 	ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
186 	if ((ledout & mask) != (PCA963X_LED_GRP_PWM << shift))
187 		i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
188 			(ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift));
189 	mutex_unlock(&pca963x->chip->mutex);
190 }
191 
192 static int pca963x_power_state(struct pca963x_led *pca963x)
193 {
194 	unsigned long *leds_on = &pca963x->chip->leds_on;
195 	unsigned long cached_leds = pca963x->chip->leds_on;
196 
197 	if (pca963x->led_cdev.brightness)
198 		set_bit(pca963x->led_num, leds_on);
199 	else
200 		clear_bit(pca963x->led_num, leds_on);
201 
202 	if (!(*leds_on) != !cached_leds)
203 		return i2c_smbus_write_byte_data(pca963x->chip->client,
204 			PCA963X_MODE1, *leds_on ? 0 : BIT(4));
205 
206 	return 0;
207 }
208 
209 static int pca963x_led_set(struct led_classdev *led_cdev,
210 	enum led_brightness value)
211 {
212 	struct pca963x_led *pca963x;
213 	int ret;
214 
215 	pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);
216 
217 	mutex_lock(&pca963x->chip->mutex);
218 
219 	ret = pca963x_brightness(pca963x, value);
220 	if (ret < 0)
221 		goto unlock;
222 	ret = pca963x_power_state(pca963x);
223 
224 unlock:
225 	mutex_unlock(&pca963x->chip->mutex);
226 	return ret;
227 }
228 
229 static unsigned int pca963x_period_scale(struct pca963x_led *pca963x,
230 	unsigned int val)
231 {
232 	unsigned int scaling = pca963x->chip->chipdef->scaling;
233 
234 	return scaling ? DIV_ROUND_CLOSEST(val * scaling, 1000) : val;
235 }
236 
237 static int pca963x_blink_set(struct led_classdev *led_cdev,
238 		unsigned long *delay_on, unsigned long *delay_off)
239 {
240 	struct pca963x_led *pca963x;
241 	unsigned long time_on, time_off, period;
242 	u8 gdc, gfrq;
243 
244 	pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);
245 
246 	time_on = *delay_on;
247 	time_off = *delay_off;
248 
249 	/* If both zero, pick reasonable defaults of 500ms each */
250 	if (!time_on && !time_off) {
251 		time_on = 500;
252 		time_off = 500;
253 	}
254 
255 	period = pca963x_period_scale(pca963x, time_on + time_off);
256 
257 	/* If period not supported by hardware, default to someting sane. */
258 	if ((period < PCA963X_BLINK_PERIOD_MIN) ||
259 	    (period > PCA963X_BLINK_PERIOD_MAX)) {
260 		time_on = 500;
261 		time_off = 500;
262 		period = pca963x_period_scale(pca963x, 1000);
263 	}
264 
265 	/*
266 	 * From manual: duty cycle = (GDC / 256) ->
267 	 *	(time_on / period) = (GDC / 256) ->
268 	 *		GDC = ((time_on * 256) / period)
269 	 */
270 	gdc = (pca963x_period_scale(pca963x, time_on) * 256) / period;
271 
272 	/*
273 	 * From manual: period = ((GFRQ + 1) / 24) in seconds.
274 	 * So, period (in ms) = (((GFRQ + 1) / 24) * 1000) ->
275 	 *		GFRQ = ((period * 24 / 1000) - 1)
276 	 */
277 	gfrq = (period * 24 / 1000) - 1;
278 
279 	pca963x->gdc = gdc;
280 	pca963x->gfrq = gfrq;
281 
282 	pca963x_blink(pca963x);
283 
284 	*delay_on = time_on;
285 	*delay_off = time_off;
286 
287 	return 0;
288 }
289 
290 #if IS_ENABLED(CONFIG_OF)
291 static struct pca963x_platform_data *
292 pca963x_dt_init(struct i2c_client *client, struct pca963x_chipdef *chip)
293 {
294 	struct device_node *np = client->dev.of_node, *child;
295 	struct pca963x_platform_data *pdata;
296 	struct led_info *pca963x_leds;
297 	int count;
298 
299 	count = of_get_child_count(np);
300 	if (!count || count > chip->n_leds)
301 		return ERR_PTR(-ENODEV);
302 
303 	pca963x_leds = devm_kcalloc(&client->dev,
304 			chip->n_leds, sizeof(struct led_info), GFP_KERNEL);
305 	if (!pca963x_leds)
306 		return ERR_PTR(-ENOMEM);
307 
308 	for_each_child_of_node(np, child) {
309 		struct led_info led = {};
310 		u32 reg;
311 		int res;
312 
313 		res = of_property_read_u32(child, "reg", &reg);
314 		if ((res != 0) || (reg >= chip->n_leds))
315 			continue;
316 		led.name =
317 			of_get_property(child, "label", NULL) ? : child->name;
318 		led.default_trigger =
319 			of_get_property(child, "linux,default-trigger", NULL);
320 		pca963x_leds[reg] = led;
321 	}
322 	pdata = devm_kzalloc(&client->dev,
323 			     sizeof(struct pca963x_platform_data), GFP_KERNEL);
324 	if (!pdata)
325 		return ERR_PTR(-ENOMEM);
326 
327 	pdata->leds.leds = pca963x_leds;
328 	pdata->leds.num_leds = chip->n_leds;
329 
330 	/* default to open-drain unless totem pole (push-pull) is specified */
331 	if (of_property_read_bool(np, "nxp,totem-pole"))
332 		pdata->outdrv = PCA963X_TOTEM_POLE;
333 	else
334 		pdata->outdrv = PCA963X_OPEN_DRAIN;
335 
336 	/* default to software blinking unless hardware blinking is specified */
337 	if (of_property_read_bool(np, "nxp,hw-blink"))
338 		pdata->blink_type = PCA963X_HW_BLINK;
339 	else
340 		pdata->blink_type = PCA963X_SW_BLINK;
341 
342 	if (of_property_read_u32(np, "nxp,period-scale", &chip->scaling))
343 		chip->scaling = 1000;
344 
345 	/* default to non-inverted output, unless inverted is specified */
346 	if (of_property_read_bool(np, "nxp,inverted-out"))
347 		pdata->dir = PCA963X_INVERTED;
348 	else
349 		pdata->dir = PCA963X_NORMAL;
350 
351 	return pdata;
352 }
353 
354 static const struct of_device_id of_pca963x_match[] = {
355 	{ .compatible = "nxp,pca9632", },
356 	{ .compatible = "nxp,pca9633", },
357 	{ .compatible = "nxp,pca9634", },
358 	{ .compatible = "nxp,pca9635", },
359 	{},
360 };
361 MODULE_DEVICE_TABLE(of, of_pca963x_match);
362 #else
363 static struct pca963x_platform_data *
364 pca963x_dt_init(struct i2c_client *client, struct pca963x_chipdef *chip)
365 {
366 	return ERR_PTR(-ENODEV);
367 }
368 #endif
369 
370 static int pca963x_probe(struct i2c_client *client,
371 					const struct i2c_device_id *id)
372 {
373 	struct pca963x *pca963x_chip;
374 	struct pca963x_led *pca963x;
375 	struct pca963x_platform_data *pdata;
376 	struct pca963x_chipdef *chip;
377 	int i, err;
378 
379 	if (id) {
380 		chip = &pca963x_chipdefs[id->driver_data];
381 	} else {
382 		const struct acpi_device_id *acpi_id;
383 
384 		acpi_id = acpi_match_device(pca963x_acpi_ids, &client->dev);
385 		if (!acpi_id)
386 			return -ENODEV;
387 		chip = &pca963x_chipdefs[acpi_id->driver_data];
388 	}
389 	pdata = dev_get_platdata(&client->dev);
390 
391 	if (!pdata) {
392 		pdata = pca963x_dt_init(client, chip);
393 		if (IS_ERR(pdata)) {
394 			dev_warn(&client->dev, "could not parse configuration\n");
395 			pdata = NULL;
396 		}
397 	}
398 
399 	if (pdata && (pdata->leds.num_leds < 1 ||
400 				 pdata->leds.num_leds > chip->n_leds)) {
401 		dev_err(&client->dev, "board info must claim 1-%d LEDs",
402 								chip->n_leds);
403 		return -EINVAL;
404 	}
405 
406 	pca963x_chip = devm_kzalloc(&client->dev, sizeof(*pca963x_chip),
407 								GFP_KERNEL);
408 	if (!pca963x_chip)
409 		return -ENOMEM;
410 	pca963x = devm_kcalloc(&client->dev, chip->n_leds, sizeof(*pca963x),
411 								GFP_KERNEL);
412 	if (!pca963x)
413 		return -ENOMEM;
414 
415 	i2c_set_clientdata(client, pca963x_chip);
416 
417 	mutex_init(&pca963x_chip->mutex);
418 	pca963x_chip->chipdef = chip;
419 	pca963x_chip->client = client;
420 	pca963x_chip->leds = pca963x;
421 
422 	/* Turn off LEDs by default*/
423 	for (i = 0; i < chip->n_leds / 4; i++)
424 		i2c_smbus_write_byte_data(client, chip->ledout_base + i, 0x00);
425 
426 	for (i = 0; i < chip->n_leds; i++) {
427 		pca963x[i].led_num = i;
428 		pca963x[i].chip = pca963x_chip;
429 
430 		/* Platform data can specify LED names and default triggers */
431 		if (pdata && i < pdata->leds.num_leds) {
432 			if (pdata->leds.leds[i].name)
433 				snprintf(pca963x[i].name,
434 					 sizeof(pca963x[i].name), "pca963x:%s",
435 					 pdata->leds.leds[i].name);
436 			if (pdata->leds.leds[i].default_trigger)
437 				pca963x[i].led_cdev.default_trigger =
438 					pdata->leds.leds[i].default_trigger;
439 		}
440 		if (!pdata || i >= pdata->leds.num_leds ||
441 						!pdata->leds.leds[i].name)
442 			snprintf(pca963x[i].name, sizeof(pca963x[i].name),
443 				 "pca963x:%d:%.2x:%d", client->adapter->nr,
444 				 client->addr, i);
445 
446 		pca963x[i].led_cdev.name = pca963x[i].name;
447 		pca963x[i].led_cdev.brightness_set_blocking = pca963x_led_set;
448 
449 		if (pdata && pdata->blink_type == PCA963X_HW_BLINK)
450 			pca963x[i].led_cdev.blink_set = pca963x_blink_set;
451 
452 		err = led_classdev_register(&client->dev, &pca963x[i].led_cdev);
453 		if (err < 0)
454 			goto exit;
455 	}
456 
457 	/* Disable LED all-call address, and power down initially */
458 	i2c_smbus_write_byte_data(client, PCA963X_MODE1, BIT(4));
459 
460 	if (pdata) {
461 		u8 mode2 = i2c_smbus_read_byte_data(pca963x->chip->client,
462 						    PCA963X_MODE2);
463 		/* Configure output: open-drain or totem pole (push-pull) */
464 		if (pdata->outdrv == PCA963X_OPEN_DRAIN)
465 			mode2 |= 0x01;
466 		else
467 			mode2 |= 0x05;
468 		/* Configure direction: normal or inverted */
469 		if (pdata->dir == PCA963X_INVERTED)
470 			mode2 |= 0x10;
471 		i2c_smbus_write_byte_data(pca963x->chip->client, PCA963X_MODE2,
472 					  mode2);
473 	}
474 
475 	return 0;
476 
477 exit:
478 	while (i--)
479 		led_classdev_unregister(&pca963x[i].led_cdev);
480 
481 	return err;
482 }
483 
484 static int pca963x_remove(struct i2c_client *client)
485 {
486 	struct pca963x *pca963x = i2c_get_clientdata(client);
487 	int i;
488 
489 	for (i = 0; i < pca963x->chipdef->n_leds; i++)
490 		led_classdev_unregister(&pca963x->leds[i].led_cdev);
491 
492 	return 0;
493 }
494 
495 static struct i2c_driver pca963x_driver = {
496 	.driver = {
497 		.name	= "leds-pca963x",
498 		.of_match_table = of_match_ptr(of_pca963x_match),
499 		.acpi_match_table = ACPI_PTR(pca963x_acpi_ids),
500 	},
501 	.probe	= pca963x_probe,
502 	.remove	= pca963x_remove,
503 	.id_table = pca963x_id,
504 };
505 
506 module_i2c_driver(pca963x_driver);
507 
508 MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>");
509 MODULE_DESCRIPTION("PCA963X LED driver");
510 MODULE_LICENSE("GPL v2");
511