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/drivers/leds/leds-lp5521.c

https://bitbucket.org/ndreys/linux-sunxi
C | 804 lines | 616 code | 134 blank | 54 comment | 73 complexity | ff9067c6b5005d6aef6e678a4fa58c97 MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
  1/*
  2 * LP5521 LED chip driver.
  3 *
  4 * Copyright (C) 2010 Nokia Corporation
  5 *
  6 * Contact: Samu Onkalo <samu.p.onkalo@nokia.com>
  7 *
  8 * This program is free software; you can redistribute it and/or
  9 * modify it under the terms of the GNU General Public License
 10 * version 2 as published by the Free Software Foundation.
 11 *
 12 * This program is distributed in the hope that it will be useful, but
 13 * WITHOUT ANY WARRANTY; without even the implied warranty of
 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
 15 * General Public License for more details.
 16 *
 17 * You should have received a copy of the GNU General Public License
 18 * along with this program; if not, write to the Free Software
 19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 20 * 02110-1301 USA
 21 */
 22
 23#include <linux/module.h>
 24#include <linux/init.h>
 25#include <linux/i2c.h>
 26#include <linux/mutex.h>
 27#include <linux/gpio.h>
 28#include <linux/interrupt.h>
 29#include <linux/delay.h>
 30#include <linux/ctype.h>
 31#include <linux/spinlock.h>
 32#include <linux/wait.h>
 33#include <linux/leds.h>
 34#include <linux/leds-lp5521.h>
 35#include <linux/workqueue.h>
 36#include <linux/slab.h>
 37
 38#define LP5521_PROGRAM_LENGTH		32	/* in bytes */
 39
 40#define LP5521_MAX_LEDS			3	/* Maximum number of LEDs */
 41#define LP5521_MAX_ENGINES		3	/* Maximum number of engines */
 42
 43#define LP5521_ENG_MASK_BASE		0x30	/* 00110000 */
 44#define LP5521_ENG_STATUS_MASK		0x07	/* 00000111 */
 45
 46#define LP5521_CMD_LOAD			0x15	/* 00010101 */
 47#define LP5521_CMD_RUN			0x2a	/* 00101010 */
 48#define LP5521_CMD_DIRECT		0x3f	/* 00111111 */
 49#define LP5521_CMD_DISABLED		0x00	/* 00000000 */
 50
 51/* Registers */
 52#define LP5521_REG_ENABLE		0x00
 53#define LP5521_REG_OP_MODE		0x01
 54#define LP5521_REG_R_PWM		0x02
 55#define LP5521_REG_G_PWM		0x03
 56#define LP5521_REG_B_PWM		0x04
 57#define LP5521_REG_R_CURRENT		0x05
 58#define LP5521_REG_G_CURRENT		0x06
 59#define LP5521_REG_B_CURRENT		0x07
 60#define LP5521_REG_CONFIG		0x08
 61#define LP5521_REG_R_CHANNEL_PC		0x09
 62#define LP5521_REG_G_CHANNEL_PC		0x0A
 63#define LP5521_REG_B_CHANNEL_PC		0x0B
 64#define LP5521_REG_STATUS		0x0C
 65#define LP5521_REG_RESET		0x0D
 66#define LP5521_REG_GPO			0x0E
 67#define LP5521_REG_R_PROG_MEM		0x10
 68#define LP5521_REG_G_PROG_MEM		0x30
 69#define LP5521_REG_B_PROG_MEM		0x50
 70
 71#define LP5521_PROG_MEM_BASE		LP5521_REG_R_PROG_MEM
 72#define LP5521_PROG_MEM_SIZE		0x20
 73
 74/* Base register to set LED current */
 75#define LP5521_REG_LED_CURRENT_BASE	LP5521_REG_R_CURRENT
 76
 77/* Base register to set the brightness */
 78#define LP5521_REG_LED_PWM_BASE		LP5521_REG_R_PWM
 79
 80/* Bits in ENABLE register */
 81#define LP5521_MASTER_ENABLE		0x40	/* Chip master enable */
 82#define LP5521_LOGARITHMIC_PWM		0x80	/* Logarithmic PWM adjustment */
 83#define LP5521_EXEC_RUN			0x2A
 84
 85/* Bits in CONFIG register */
 86#define LP5521_PWM_HF			0x40	/* PWM: 0 = 256Hz, 1 = 558Hz */
 87#define LP5521_PWRSAVE_EN		0x20	/* 1 = Power save mode */
 88#define LP5521_CP_MODE_OFF		0	/* Charge pump (CP) off */
 89#define LP5521_CP_MODE_BYPASS		8	/* CP forced to bypass mode */
 90#define LP5521_CP_MODE_1X5		0x10	/* CP forced to 1.5x mode */
 91#define LP5521_CP_MODE_AUTO		0x18	/* Automatic mode selection */
 92#define LP5521_R_TO_BATT		4	/* R out: 0 = CP, 1 = Vbat */
 93#define LP5521_CLK_SRC_EXT		0	/* Ext-clk source (CLK_32K) */
 94#define LP5521_CLK_INT			1	/* Internal clock */
 95#define LP5521_CLK_AUTO			2	/* Automatic clock selection */
 96
 97/* Status */
 98#define LP5521_EXT_CLK_USED		0x08
 99
100struct lp5521_engine {
101	int		id;
102	u8		mode;
103	u8		prog_page;
104	u8		engine_mask;
105};
106
107struct lp5521_led {
108	int			id;
109	u8			chan_nr;
110	u8			led_current;
111	u8			max_current;
112	struct led_classdev	cdev;
113	struct work_struct	brightness_work;
114	u8			brightness;
115};
116
117struct lp5521_chip {
118	struct lp5521_platform_data *pdata;
119	struct mutex		lock; /* Serialize control */
120	struct i2c_client	*client;
121	struct lp5521_engine	engines[LP5521_MAX_ENGINES];
122	struct lp5521_led	leds[LP5521_MAX_LEDS];
123	u8			num_channels;
124	u8			num_leds;
125};
126
127static inline struct lp5521_led *cdev_to_led(struct led_classdev *cdev)
128{
129	return container_of(cdev, struct lp5521_led, cdev);
130}
131
132static inline struct lp5521_chip *engine_to_lp5521(struct lp5521_engine *engine)
133{
134	return container_of(engine, struct lp5521_chip,
135			    engines[engine->id - 1]);
136}
137
138static inline struct lp5521_chip *led_to_lp5521(struct lp5521_led *led)
139{
140	return container_of(led, struct lp5521_chip,
141			    leds[led->id]);
142}
143
144static void lp5521_led_brightness_work(struct work_struct *work);
145
146static inline int lp5521_write(struct i2c_client *client, u8 reg, u8 value)
147{
148	return i2c_smbus_write_byte_data(client, reg, value);
149}
150
151static int lp5521_read(struct i2c_client *client, u8 reg, u8 *buf)
152{
153	s32 ret;
154
155	ret = i2c_smbus_read_byte_data(client, reg);
156	if (ret < 0)
157		return -EIO;
158
159	*buf = ret;
160	return 0;
161}
162
163static int lp5521_set_engine_mode(struct lp5521_engine *engine, u8 mode)
164{
165	struct lp5521_chip *chip = engine_to_lp5521(engine);
166	struct i2c_client *client = chip->client;
167	int ret;
168	u8 engine_state;
169
170	/* Only transition between RUN and DIRECT mode are handled here */
171	if (mode == LP5521_CMD_LOAD)
172		return 0;
173
174	if (mode == LP5521_CMD_DISABLED)
175		mode = LP5521_CMD_DIRECT;
176
177	ret = lp5521_read(client, LP5521_REG_OP_MODE, &engine_state);
178
179	/* set mode only for this engine */
180	engine_state &= ~(engine->engine_mask);
181	mode &= engine->engine_mask;
182	engine_state |= mode;
183	ret |= lp5521_write(client, LP5521_REG_OP_MODE, engine_state);
184
185	return ret;
186}
187
188static int lp5521_load_program(struct lp5521_engine *eng, const u8 *pattern)
189{
190	struct lp5521_chip *chip = engine_to_lp5521(eng);
191	struct i2c_client *client = chip->client;
192	int ret;
193	int addr;
194	u8 mode;
195
196	/* move current engine to direct mode and remember the state */
197	ret = lp5521_set_engine_mode(eng, LP5521_CMD_DIRECT);
198	/* Mode change requires min 500 us delay. 1 - 2 ms  with margin */
199	usleep_range(1000, 2000);
200	ret |= lp5521_read(client, LP5521_REG_OP_MODE, &mode);
201
202	/* For loading, all the engines to load mode */
203	lp5521_write(client, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT);
204	/* Mode change requires min 500 us delay. 1 - 2 ms  with margin */
205	usleep_range(1000, 2000);
206	lp5521_write(client, LP5521_REG_OP_MODE, LP5521_CMD_LOAD);
207	/* Mode change requires min 500 us delay. 1 - 2 ms  with margin */
208	usleep_range(1000, 2000);
209
210	addr = LP5521_PROG_MEM_BASE + eng->prog_page * LP5521_PROG_MEM_SIZE;
211	i2c_smbus_write_i2c_block_data(client,
212				addr,
213				LP5521_PROG_MEM_SIZE,
214				pattern);
215
216	ret |= lp5521_write(client, LP5521_REG_OP_MODE, mode);
217	return ret;
218}
219
220static int lp5521_set_led_current(struct lp5521_chip *chip, int led, u8 curr)
221{
222	return lp5521_write(chip->client,
223		    LP5521_REG_LED_CURRENT_BASE + chip->leds[led].chan_nr,
224		    curr);
225}
226
227static void lp5521_init_engine(struct lp5521_chip *chip)
228{
229	int i;
230	for (i = 0; i < ARRAY_SIZE(chip->engines); i++) {
231		chip->engines[i].id = i + 1;
232		chip->engines[i].engine_mask = LP5521_ENG_MASK_BASE >> (i * 2);
233		chip->engines[i].prog_page = i;
234	}
235}
236
237static int lp5521_configure(struct i2c_client *client)
238{
239	struct lp5521_chip *chip = i2c_get_clientdata(client);
240	int ret;
241
242	lp5521_init_engine(chip);
243
244	/* Set all PWMs to direct control mode */
245	ret = lp5521_write(client, LP5521_REG_OP_MODE, 0x3F);
246
247	/* Enable auto-powersave, set charge pump to auto, red to battery */
248	ret |= lp5521_write(client, LP5521_REG_CONFIG,
249		LP5521_PWRSAVE_EN | LP5521_CP_MODE_AUTO | LP5521_R_TO_BATT);
250
251	/* Initialize all channels PWM to zero -> leds off */
252	ret |= lp5521_write(client, LP5521_REG_R_PWM, 0);
253	ret |= lp5521_write(client, LP5521_REG_G_PWM, 0);
254	ret |= lp5521_write(client, LP5521_REG_B_PWM, 0);
255
256	/* Set engines are set to run state when OP_MODE enables engines */
257	ret |= lp5521_write(client, LP5521_REG_ENABLE,
258			LP5521_MASTER_ENABLE | LP5521_LOGARITHMIC_PWM |
259			LP5521_EXEC_RUN);
260	/* enable takes 500us. 1 - 2 ms leaves some margin */
261	usleep_range(1000, 2000);
262
263	return ret;
264}
265
266static int lp5521_run_selftest(struct lp5521_chip *chip, char *buf)
267{
268	int ret;
269	u8 status;
270
271	ret = lp5521_read(chip->client, LP5521_REG_STATUS, &status);
272	if (ret < 0)
273		return ret;
274
275	/* Check that ext clock is really in use if requested */
276	if (chip->pdata && chip->pdata->clock_mode == LP5521_CLOCK_EXT)
277		if  ((status & LP5521_EXT_CLK_USED) == 0)
278			return -EIO;
279	return 0;
280}
281
282static void lp5521_set_brightness(struct led_classdev *cdev,
283			     enum led_brightness brightness)
284{
285	struct lp5521_led *led = cdev_to_led(cdev);
286	led->brightness = (u8)brightness;
287	schedule_work(&led->brightness_work);
288}
289
290static void lp5521_led_brightness_work(struct work_struct *work)
291{
292	struct lp5521_led *led = container_of(work,
293					      struct lp5521_led,
294					      brightness_work);
295	struct lp5521_chip *chip = led_to_lp5521(led);
296	struct i2c_client *client = chip->client;
297
298	mutex_lock(&chip->lock);
299	lp5521_write(client, LP5521_REG_LED_PWM_BASE + led->chan_nr,
300		led->brightness);
301	mutex_unlock(&chip->lock);
302}
303
304/* Detect the chip by setting its ENABLE register and reading it back. */
305static int lp5521_detect(struct i2c_client *client)
306{
307	int ret;
308	u8 buf;
309
310	ret = lp5521_write(client, LP5521_REG_ENABLE,
311			LP5521_MASTER_ENABLE | LP5521_LOGARITHMIC_PWM);
312	if (ret)
313		return ret;
314	/* enable takes 500us. 1 - 2 ms leaves some margin */
315	usleep_range(1000, 2000);
316	ret = lp5521_read(client, LP5521_REG_ENABLE, &buf);
317	if (ret)
318		return ret;
319	if (buf != (LP5521_MASTER_ENABLE | LP5521_LOGARITHMIC_PWM))
320		return -ENODEV;
321
322	return 0;
323}
324
325/* Set engine mode and create appropriate sysfs attributes, if required. */
326static int lp5521_set_mode(struct lp5521_engine *engine, u8 mode)
327{
328	int ret = 0;
329
330	/* if in that mode already do nothing, except for run */
331	if (mode == engine->mode && mode != LP5521_CMD_RUN)
332		return 0;
333
334	if (mode == LP5521_CMD_RUN) {
335		ret = lp5521_set_engine_mode(engine, LP5521_CMD_RUN);
336	} else if (mode == LP5521_CMD_LOAD) {
337		lp5521_set_engine_mode(engine, LP5521_CMD_DISABLED);
338		lp5521_set_engine_mode(engine, LP5521_CMD_LOAD);
339	} else if (mode == LP5521_CMD_DISABLED) {
340		lp5521_set_engine_mode(engine, LP5521_CMD_DISABLED);
341	}
342
343	engine->mode = mode;
344
345	return ret;
346}
347
348static int lp5521_do_store_load(struct lp5521_engine *engine,
349				const char *buf, size_t len)
350{
351	struct lp5521_chip *chip = engine_to_lp5521(engine);
352	struct i2c_client *client = chip->client;
353	int  ret, nrchars, offset = 0, i = 0;
354	char c[3];
355	unsigned cmd;
356	u8 pattern[LP5521_PROGRAM_LENGTH] = {0};
357
358	while ((offset < len - 1) && (i < LP5521_PROGRAM_LENGTH)) {
359		/* separate sscanfs because length is working only for %s */
360		ret = sscanf(buf + offset, "%2s%n ", c, &nrchars);
361		if (ret != 2)
362			goto fail;
363		ret = sscanf(c, "%2x", &cmd);
364		if (ret != 1)
365			goto fail;
366		pattern[i] = (u8)cmd;
367
368		offset += nrchars;
369		i++;
370	}
371
372	/* Each instruction is 16bit long. Check that length is even */
373	if (i % 2)
374		goto fail;
375
376	mutex_lock(&chip->lock);
377	if (engine->mode == LP5521_CMD_LOAD)
378		ret = lp5521_load_program(engine, pattern);
379	else
380		ret = -EINVAL;
381	mutex_unlock(&chip->lock);
382
383	if (ret) {
384		dev_err(&client->dev, "failed loading pattern\n");
385		return ret;
386	}
387
388	return len;
389fail:
390	dev_err(&client->dev, "wrong pattern format\n");
391	return -EINVAL;
392}
393
394static ssize_t store_engine_load(struct device *dev,
395				     struct device_attribute *attr,
396				     const char *buf, size_t len, int nr)
397{
398	struct i2c_client *client = to_i2c_client(dev);
399	struct lp5521_chip *chip = i2c_get_clientdata(client);
400	return lp5521_do_store_load(&chip->engines[nr - 1], buf, len);
401}
402
403#define store_load(nr)							\
404static ssize_t store_engine##nr##_load(struct device *dev,		\
405				     struct device_attribute *attr,	\
406				     const char *buf, size_t len)	\
407{									\
408	return store_engine_load(dev, attr, buf, len, nr);		\
409}
410store_load(1)
411store_load(2)
412store_load(3)
413
414static ssize_t show_engine_mode(struct device *dev,
415				struct device_attribute *attr,
416				char *buf, int nr)
417{
418	struct i2c_client *client = to_i2c_client(dev);
419	struct lp5521_chip *chip = i2c_get_clientdata(client);
420	switch (chip->engines[nr - 1].mode) {
421	case LP5521_CMD_RUN:
422		return sprintf(buf, "run\n");
423	case LP5521_CMD_LOAD:
424		return sprintf(buf, "load\n");
425	case LP5521_CMD_DISABLED:
426		return sprintf(buf, "disabled\n");
427	default:
428		return sprintf(buf, "disabled\n");
429	}
430}
431
432#define show_mode(nr)							\
433static ssize_t show_engine##nr##_mode(struct device *dev,		\
434				    struct device_attribute *attr,	\
435				    char *buf)				\
436{									\
437	return show_engine_mode(dev, attr, buf, nr);			\
438}
439show_mode(1)
440show_mode(2)
441show_mode(3)
442
443static ssize_t store_engine_mode(struct device *dev,
444				 struct device_attribute *attr,
445				 const char *buf, size_t len, int nr)
446{
447	struct i2c_client *client = to_i2c_client(dev);
448	struct lp5521_chip *chip = i2c_get_clientdata(client);
449	struct lp5521_engine *engine = &chip->engines[nr - 1];
450	mutex_lock(&chip->lock);
451
452	if (!strncmp(buf, "run", 3))
453		lp5521_set_mode(engine, LP5521_CMD_RUN);
454	else if (!strncmp(buf, "load", 4))
455		lp5521_set_mode(engine, LP5521_CMD_LOAD);
456	else if (!strncmp(buf, "disabled", 8))
457		lp5521_set_mode(engine, LP5521_CMD_DISABLED);
458
459	mutex_unlock(&chip->lock);
460	return len;
461}
462
463#define store_mode(nr)							\
464static ssize_t store_engine##nr##_mode(struct device *dev,		\
465				     struct device_attribute *attr,	\
466				     const char *buf, size_t len)	\
467{									\
468	return store_engine_mode(dev, attr, buf, len, nr);		\
469}
470store_mode(1)
471store_mode(2)
472store_mode(3)
473
474static ssize_t show_max_current(struct device *dev,
475			    struct device_attribute *attr,
476			    char *buf)
477{
478	struct led_classdev *led_cdev = dev_get_drvdata(dev);
479	struct lp5521_led *led = cdev_to_led(led_cdev);
480
481	return sprintf(buf, "%d\n", led->max_current);
482}
483
484static ssize_t show_current(struct device *dev,
485			    struct device_attribute *attr,
486			    char *buf)
487{
488	struct led_classdev *led_cdev = dev_get_drvdata(dev);
489	struct lp5521_led *led = cdev_to_led(led_cdev);
490
491	return sprintf(buf, "%d\n", led->led_current);
492}
493
494static ssize_t store_current(struct device *dev,
495			     struct device_attribute *attr,
496			     const char *buf, size_t len)
497{
498	struct led_classdev *led_cdev = dev_get_drvdata(dev);
499	struct lp5521_led *led = cdev_to_led(led_cdev);
500	struct lp5521_chip *chip = led_to_lp5521(led);
501	ssize_t ret;
502	unsigned long curr;
503
504	if (strict_strtoul(buf, 0, &curr))
505		return -EINVAL;
506
507	if (curr > led->max_current)
508		return -EINVAL;
509
510	mutex_lock(&chip->lock);
511	ret = lp5521_set_led_current(chip, led->id, curr);
512	mutex_unlock(&chip->lock);
513
514	if (ret < 0)
515		return ret;
516
517	led->led_current = (u8)curr;
518
519	return len;
520}
521
522static ssize_t lp5521_selftest(struct device *dev,
523			       struct device_attribute *attr,
524			       char *buf)
525{
526	struct i2c_client *client = to_i2c_client(dev);
527	struct lp5521_chip *chip = i2c_get_clientdata(client);
528	int ret;
529
530	mutex_lock(&chip->lock);
531	ret = lp5521_run_selftest(chip, buf);
532	mutex_unlock(&chip->lock);
533	return sprintf(buf, "%s\n", ret ? "FAIL" : "OK");
534}
535
536/* led class device attributes */
537static DEVICE_ATTR(led_current, S_IRUGO | S_IWUSR, show_current, store_current);
538static DEVICE_ATTR(max_current, S_IRUGO , show_max_current, NULL);
539
540static struct attribute *lp5521_led_attributes[] = {
541	&dev_attr_led_current.attr,
542	&dev_attr_max_current.attr,
543	NULL,
544};
545
546static struct attribute_group lp5521_led_attribute_group = {
547	.attrs = lp5521_led_attributes
548};
549
550/* device attributes */
551static DEVICE_ATTR(engine1_mode, S_IRUGO | S_IWUSR,
552		   show_engine1_mode, store_engine1_mode);
553static DEVICE_ATTR(engine2_mode, S_IRUGO | S_IWUSR,
554		   show_engine2_mode, store_engine2_mode);
555static DEVICE_ATTR(engine3_mode, S_IRUGO | S_IWUSR,
556		   show_engine3_mode, store_engine3_mode);
557static DEVICE_ATTR(engine1_load, S_IWUSR, NULL, store_engine1_load);
558static DEVICE_ATTR(engine2_load, S_IWUSR, NULL, store_engine2_load);
559static DEVICE_ATTR(engine3_load, S_IWUSR, NULL, store_engine3_load);
560static DEVICE_ATTR(selftest, S_IRUGO, lp5521_selftest, NULL);
561
562static struct attribute *lp5521_attributes[] = {
563	&dev_attr_engine1_mode.attr,
564	&dev_attr_engine2_mode.attr,
565	&dev_attr_engine3_mode.attr,
566	&dev_attr_selftest.attr,
567	&dev_attr_engine1_load.attr,
568	&dev_attr_engine2_load.attr,
569	&dev_attr_engine3_load.attr,
570	NULL
571};
572
573static const struct attribute_group lp5521_group = {
574	.attrs = lp5521_attributes,
575};
576
577static int lp5521_register_sysfs(struct i2c_client *client)
578{
579	struct device *dev = &client->dev;
580	return sysfs_create_group(&dev->kobj, &lp5521_group);
581}
582
583static void lp5521_unregister_sysfs(struct i2c_client *client)
584{
585	struct lp5521_chip *chip = i2c_get_clientdata(client);
586	struct device *dev = &client->dev;
587	int i;
588
589	sysfs_remove_group(&dev->kobj, &lp5521_group);
590
591	for (i = 0; i < chip->num_leds; i++)
592		sysfs_remove_group(&chip->leds[i].cdev.dev->kobj,
593				&lp5521_led_attribute_group);
594}
595
596static int __devinit lp5521_init_led(struct lp5521_led *led,
597				struct i2c_client *client,
598				int chan, struct lp5521_platform_data *pdata)
599{
600	struct device *dev = &client->dev;
601	char name[32];
602	int res;
603
604	if (chan >= LP5521_MAX_LEDS)
605		return -EINVAL;
606
607	if (pdata->led_config[chan].led_current == 0)
608		return 0;
609
610	led->led_current = pdata->led_config[chan].led_current;
611	led->max_current = pdata->led_config[chan].max_current;
612	led->chan_nr = pdata->led_config[chan].chan_nr;
613
614	if (led->chan_nr >= LP5521_MAX_LEDS) {
615		dev_err(dev, "Use channel numbers between 0 and %d\n",
616			LP5521_MAX_LEDS - 1);
617		return -EINVAL;
618	}
619
620	snprintf(name, sizeof(name), "%s:channel%d",
621			pdata->label ?: client->name, chan);
622	led->cdev.brightness_set = lp5521_set_brightness;
623	led->cdev.name = name;
624	res = led_classdev_register(dev, &led->cdev);
625	if (res < 0) {
626		dev_err(dev, "couldn't register led on channel %d\n", chan);
627		return res;
628	}
629
630	res = sysfs_create_group(&led->cdev.dev->kobj,
631			&lp5521_led_attribute_group);
632	if (res < 0) {
633		dev_err(dev, "couldn't register current attribute\n");
634		led_classdev_unregister(&led->cdev);
635		return res;
636	}
637	return 0;
638}
639
640static int __devinit lp5521_probe(struct i2c_client *client,
641			const struct i2c_device_id *id)
642{
643	struct lp5521_chip		*chip;
644	struct lp5521_platform_data	*pdata;
645	int ret, i, led;
646
647	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
648	if (!chip)
649		return -ENOMEM;
650
651	i2c_set_clientdata(client, chip);
652	chip->client = client;
653
654	pdata = client->dev.platform_data;
655
656	if (!pdata) {
657		dev_err(&client->dev, "no platform data\n");
658		ret = -EINVAL;
659		goto fail1;
660	}
661
662	mutex_init(&chip->lock);
663
664	chip->pdata   = pdata;
665
666	if (pdata->setup_resources) {
667		ret = pdata->setup_resources();
668		if (ret < 0)
669			goto fail1;
670	}
671
672	if (pdata->enable) {
673		pdata->enable(0);
674		usleep_range(1000, 2000); /* Keep enable down at least 1ms */
675		pdata->enable(1);
676		usleep_range(1000, 2000); /* 500us abs min. */
677	}
678
679	lp5521_write(client, LP5521_REG_RESET, 0xff);
680	usleep_range(10000, 20000); /*
681				     * Exact value is not available. 10 - 20ms
682				     * appears to be enough for reset.
683				     */
684	ret = lp5521_detect(client);
685
686	if (ret) {
687		dev_err(&client->dev, "Chip not found\n");
688		goto fail2;
689	}
690
691	dev_info(&client->dev, "%s programmable led chip found\n", id->name);
692
693	ret = lp5521_configure(client);
694	if (ret < 0) {
695		dev_err(&client->dev, "error configuring chip\n");
696		goto fail2;
697	}
698
699	/* Initialize leds */
700	chip->num_channels = pdata->num_channels;
701	chip->num_leds = 0;
702	led = 0;
703	for (i = 0; i < pdata->num_channels; i++) {
704		/* Do not initialize channels that are not connected */
705		if (pdata->led_config[i].led_current == 0)
706			continue;
707
708		ret = lp5521_init_led(&chip->leds[led], client, i, pdata);
709		if (ret) {
710			dev_err(&client->dev, "error initializing leds\n");
711			goto fail3;
712		}
713		chip->num_leds++;
714
715		chip->leds[led].id = led;
716		/* Set initial LED current */
717		lp5521_set_led_current(chip, led,
718				chip->leds[led].led_current);
719
720		INIT_WORK(&(chip->leds[led].brightness_work),
721			lp5521_led_brightness_work);
722
723		led++;
724	}
725
726	ret = lp5521_register_sysfs(client);
727	if (ret) {
728		dev_err(&client->dev, "registering sysfs failed\n");
729		goto fail3;
730	}
731	return ret;
732fail3:
733	for (i = 0; i < chip->num_leds; i++) {
734		led_classdev_unregister(&chip->leds[i].cdev);
735		cancel_work_sync(&chip->leds[i].brightness_work);
736	}
737fail2:
738	if (pdata->enable)
739		pdata->enable(0);
740	if (pdata->release_resources)
741		pdata->release_resources();
742fail1:
743	kfree(chip);
744	return ret;
745}
746
747static int lp5521_remove(struct i2c_client *client)
748{
749	struct lp5521_chip *chip = i2c_get_clientdata(client);
750	int i;
751
752	lp5521_unregister_sysfs(client);
753
754	for (i = 0; i < chip->num_leds; i++) {
755		led_classdev_unregister(&chip->leds[i].cdev);
756		cancel_work_sync(&chip->leds[i].brightness_work);
757	}
758
759	if (chip->pdata->enable)
760		chip->pdata->enable(0);
761	if (chip->pdata->release_resources)
762		chip->pdata->release_resources();
763	kfree(chip);
764	return 0;
765}
766
767static const struct i2c_device_id lp5521_id[] = {
768	{ "lp5521", 0 }, /* Three channel chip */
769	{ }
770};
771MODULE_DEVICE_TABLE(i2c, lp5521_id);
772
773static struct i2c_driver lp5521_driver = {
774	.driver = {
775		.name	= "lp5521",
776	},
777	.probe		= lp5521_probe,
778	.remove		= lp5521_remove,
779	.id_table	= lp5521_id,
780};
781
782static int __init lp5521_init(void)
783{
784	int ret;
785
786	ret = i2c_add_driver(&lp5521_driver);
787
788	if (ret < 0)
789		printk(KERN_ALERT "Adding lp5521 driver failed\n");
790
791	return ret;
792}
793
794static void __exit lp5521_exit(void)
795{
796	i2c_del_driver(&lp5521_driver);
797}
798
799module_init(lp5521_init);
800module_exit(lp5521_exit);
801
802MODULE_AUTHOR("Mathias Nyman, Yuri Zaporozhets, Samu Onkalo");
803MODULE_DESCRIPTION("LP5521 LED engine");
804MODULE_LICENSE("GPL v2");