xref: /linux/drivers/leds/leds-lp5523.c (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
1 /*
2  * lp5523.c - LP5523 LED 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-lp5523.h>
35 #include <linux/workqueue.h>
36 #include <linux/slab.h>
37 
38 #define LP5523_REG_ENABLE		0x00
39 #define LP5523_REG_OP_MODE		0x01
40 #define LP5523_REG_RATIOMETRIC_MSB	0x02
41 #define LP5523_REG_RATIOMETRIC_LSB	0x03
42 #define LP5523_REG_ENABLE_LEDS_MSB	0x04
43 #define LP5523_REG_ENABLE_LEDS_LSB	0x05
44 #define LP5523_REG_LED_CNTRL_BASE	0x06
45 #define LP5523_REG_LED_PWM_BASE		0x16
46 #define LP5523_REG_LED_CURRENT_BASE	0x26
47 #define LP5523_REG_CONFIG		0x36
48 #define LP5523_REG_CHANNEL1_PC		0x37
49 #define LP5523_REG_CHANNEL2_PC		0x38
50 #define LP5523_REG_CHANNEL3_PC		0x39
51 #define LP5523_REG_STATUS		0x3a
52 #define LP5523_REG_GPO			0x3b
53 #define LP5523_REG_VARIABLE		0x3c
54 #define LP5523_REG_RESET		0x3d
55 #define LP5523_REG_TEMP_CTRL		0x3e
56 #define LP5523_REG_TEMP_READ		0x3f
57 #define LP5523_REG_TEMP_WRITE		0x40
58 #define LP5523_REG_LED_TEST_CTRL	0x41
59 #define LP5523_REG_LED_TEST_ADC		0x42
60 #define LP5523_REG_ENG1_VARIABLE	0x45
61 #define LP5523_REG_ENG2_VARIABLE	0x46
62 #define LP5523_REG_ENG3_VARIABLE	0x47
63 #define LP5523_REG_MASTER_FADER1	0x48
64 #define LP5523_REG_MASTER_FADER2	0x49
65 #define LP5523_REG_MASTER_FADER3	0x4a
66 #define LP5523_REG_CH1_PROG_START	0x4c
67 #define LP5523_REG_CH2_PROG_START	0x4d
68 #define LP5523_REG_CH3_PROG_START	0x4e
69 #define LP5523_REG_PROG_PAGE_SEL	0x4f
70 #define LP5523_REG_PROG_MEM		0x50
71 
72 #define LP5523_CMD_LOAD			0x15 /* 00010101 */
73 #define LP5523_CMD_RUN			0x2a /* 00101010 */
74 #define LP5523_CMD_DISABLED		0x00 /* 00000000 */
75 
76 #define LP5523_ENABLE			0x40
77 #define LP5523_AUTO_INC			0x40
78 #define LP5523_PWR_SAVE			0x20
79 #define LP5523_PWM_PWR_SAVE		0x04
80 #define LP5523_CP_1			0x08
81 #define LP5523_CP_1_5			0x10
82 #define LP5523_CP_AUTO			0x18
83 #define LP5523_INT_CLK			0x01
84 #define LP5523_AUTO_CLK			0x02
85 #define LP5523_EN_LEDTEST		0x80
86 #define LP5523_LEDTEST_DONE		0x80
87 
88 #define LP5523_DEFAULT_CURRENT		50 /* microAmps */
89 #define LP5523_PROGRAM_LENGTH		32 /* in bytes */
90 #define LP5523_PROGRAM_PAGES		6
91 #define LP5523_ADC_SHORTCIRC_LIM	80
92 
93 #define LP5523_LEDS			9
94 #define LP5523_ENGINES			3
95 
96 #define LP5523_ENG_MASK_BASE		0x30 /* 00110000 */
97 
98 #define LP5523_ENG_STATUS_MASK          0x07 /* 00000111 */
99 
100 #define LP5523_IRQ_FLAGS                IRQF_TRIGGER_FALLING
101 
102 #define LP5523_EXT_CLK_USED		0x08
103 
104 #define LED_ACTIVE(mux, led)		(!!(mux & (0x0001 << led)))
105 #define SHIFT_MASK(id)			(((id) - 1) * 2)
106 
107 struct lp5523_engine {
108 	int		id;
109 	u8		mode;
110 	u8		prog_page;
111 	u8		mux_page;
112 	u16		led_mux;
113 	u8		engine_mask;
114 };
115 
116 struct lp5523_led {
117 	int			id;
118 	u8			chan_nr;
119 	u8			led_current;
120 	u8			max_current;
121 	struct led_classdev     cdev;
122 	struct work_struct	brightness_work;
123 	u8			brightness;
124 };
125 
126 struct lp5523_chip {
127 	struct mutex		lock; /* Serialize control */
128 	struct i2c_client	*client;
129 	struct lp5523_engine	engines[LP5523_ENGINES];
130 	struct lp5523_led	leds[LP5523_LEDS];
131 	struct lp5523_platform_data *pdata;
132 	u8			num_channels;
133 	u8			num_leds;
134 };
135 
136 static inline struct lp5523_led *cdev_to_led(struct led_classdev *cdev)
137 {
138 	return container_of(cdev, struct lp5523_led, cdev);
139 }
140 
141 static inline struct lp5523_chip *engine_to_lp5523(struct lp5523_engine *engine)
142 {
143 	return container_of(engine, struct lp5523_chip,
144 			    engines[engine->id - 1]);
145 }
146 
147 static inline struct lp5523_chip *led_to_lp5523(struct lp5523_led *led)
148 {
149 	return container_of(led, struct lp5523_chip,
150 			    leds[led->id]);
151 }
152 
153 static int lp5523_set_mode(struct lp5523_engine *engine, u8 mode);
154 static int lp5523_set_engine_mode(struct lp5523_engine *engine, u8 mode);
155 static int lp5523_load_program(struct lp5523_engine *engine, u8 *pattern);
156 
157 static void lp5523_led_brightness_work(struct work_struct *work);
158 
159 static int lp5523_write(struct i2c_client *client, u8 reg, u8 value)
160 {
161 	return i2c_smbus_write_byte_data(client, reg, value);
162 }
163 
164 static int lp5523_read(struct i2c_client *client, u8 reg, u8 *buf)
165 {
166 	s32 ret = i2c_smbus_read_byte_data(client, reg);
167 
168 	if (ret < 0)
169 		return -EIO;
170 
171 	*buf = ret;
172 	return 0;
173 }
174 
175 static int lp5523_detect(struct i2c_client *client)
176 {
177 	int ret;
178 	u8 buf;
179 
180 	ret = lp5523_write(client, LP5523_REG_ENABLE, 0x40);
181 	if (ret)
182 		return ret;
183 	ret = lp5523_read(client, LP5523_REG_ENABLE, &buf);
184 	if (ret)
185 		return ret;
186 	if (buf == 0x40)
187 		return 0;
188 	else
189 		return -ENODEV;
190 }
191 
192 static int lp5523_configure(struct i2c_client *client)
193 {
194 	struct lp5523_chip *chip = i2c_get_clientdata(client);
195 	int ret = 0;
196 	u8 status;
197 
198 	/* one pattern per engine setting led mux start and stop addresses */
199 	u8 pattern[][LP5523_PROGRAM_LENGTH] =  {
200 		{ 0x9c, 0x30, 0x9c, 0xb0, 0x9d, 0x80, 0xd8, 0x00, 0},
201 		{ 0x9c, 0x40, 0x9c, 0xc0, 0x9d, 0x80, 0xd8, 0x00, 0},
202 		{ 0x9c, 0x50, 0x9c, 0xd0, 0x9d, 0x80, 0xd8, 0x00, 0},
203 	};
204 
205 	ret |= lp5523_write(client, LP5523_REG_ENABLE, LP5523_ENABLE);
206 	/* Chip startup time is 500 us, 1 - 2 ms gives some margin */
207 	usleep_range(1000, 2000);
208 
209 	ret |= lp5523_write(client, LP5523_REG_CONFIG,
210 			    LP5523_AUTO_INC | LP5523_PWR_SAVE |
211 			    LP5523_CP_AUTO | LP5523_AUTO_CLK |
212 			    LP5523_PWM_PWR_SAVE);
213 
214 	/* turn on all leds */
215 	ret |= lp5523_write(client, LP5523_REG_ENABLE_LEDS_MSB, 0x01);
216 	ret |= lp5523_write(client, LP5523_REG_ENABLE_LEDS_LSB, 0xff);
217 
218 	/* hardcode 32 bytes of memory for each engine from program memory */
219 	ret |= lp5523_write(client, LP5523_REG_CH1_PROG_START, 0x00);
220 	ret |= lp5523_write(client, LP5523_REG_CH2_PROG_START, 0x10);
221 	ret |= lp5523_write(client, LP5523_REG_CH3_PROG_START, 0x20);
222 
223 	/* write led mux address space for each channel */
224 	ret |= lp5523_load_program(&chip->engines[0], pattern[0]);
225 	ret |= lp5523_load_program(&chip->engines[1], pattern[1]);
226 	ret |= lp5523_load_program(&chip->engines[2], pattern[2]);
227 
228 	if (ret) {
229 		dev_err(&client->dev, "could not load mux programs\n");
230 		return -1;
231 	}
232 
233 	/* set all engines exec state and mode to run 00101010 */
234 	ret |= lp5523_write(client, LP5523_REG_ENABLE,
235 			    (LP5523_CMD_RUN | LP5523_ENABLE));
236 
237 	ret |= lp5523_write(client, LP5523_REG_OP_MODE, LP5523_CMD_RUN);
238 
239 	if (ret) {
240 		dev_err(&client->dev, "could not start mux programs\n");
241 		return -1;
242 	}
243 
244 	/* Let the programs run for couple of ms and check the engine status */
245 	usleep_range(3000, 6000);
246 	lp5523_read(client, LP5523_REG_STATUS, &status);
247 	status &= LP5523_ENG_STATUS_MASK;
248 
249 	if (status == LP5523_ENG_STATUS_MASK) {
250 		dev_dbg(&client->dev, "all engines configured\n");
251 	} else {
252 		dev_info(&client->dev, "status == %x\n", status);
253 		dev_err(&client->dev, "cound not configure LED engine\n");
254 		return -1;
255 	}
256 
257 	dev_info(&client->dev, "disabling engines\n");
258 
259 	ret |= lp5523_write(client, LP5523_REG_OP_MODE, LP5523_CMD_DISABLED);
260 
261 	return ret;
262 }
263 
264 static int lp5523_set_engine_mode(struct lp5523_engine *engine, u8 mode)
265 {
266 	struct lp5523_chip *chip = engine_to_lp5523(engine);
267 	struct i2c_client *client = chip->client;
268 	int ret;
269 	u8 engine_state;
270 
271 	ret = lp5523_read(client, LP5523_REG_OP_MODE, &engine_state);
272 	if (ret)
273 		goto fail;
274 
275 	engine_state &= ~(engine->engine_mask);
276 
277 	/* set mode only for this engine */
278 	mode &= engine->engine_mask;
279 
280 	engine_state |= mode;
281 
282 	ret |= lp5523_write(client, LP5523_REG_OP_MODE, engine_state);
283 fail:
284 	return ret;
285 }
286 
287 static int lp5523_load_mux(struct lp5523_engine *engine, u16 mux)
288 {
289 	struct lp5523_chip *chip = engine_to_lp5523(engine);
290 	struct i2c_client *client = chip->client;
291 	int ret = 0;
292 
293 	ret |= lp5523_set_engine_mode(engine, LP5523_CMD_LOAD);
294 
295 	ret |= lp5523_write(client, LP5523_REG_PROG_PAGE_SEL, engine->mux_page);
296 	ret |= lp5523_write(client, LP5523_REG_PROG_MEM,
297 			    (u8)(mux >> 8));
298 	ret |= lp5523_write(client, LP5523_REG_PROG_MEM + 1, (u8)(mux));
299 	engine->led_mux = mux;
300 
301 	return ret;
302 }
303 
304 static int lp5523_load_program(struct lp5523_engine *engine, u8 *pattern)
305 {
306 	struct lp5523_chip *chip = engine_to_lp5523(engine);
307 	struct i2c_client *client = chip->client;
308 
309 	int ret = 0;
310 
311 	ret |= lp5523_set_engine_mode(engine, LP5523_CMD_LOAD);
312 
313 	ret |= lp5523_write(client, LP5523_REG_PROG_PAGE_SEL,
314 			    engine->prog_page);
315 	ret |= i2c_smbus_write_i2c_block_data(client, LP5523_REG_PROG_MEM,
316 					      LP5523_PROGRAM_LENGTH, pattern);
317 
318 	return ret;
319 }
320 
321 static int lp5523_run_program(struct lp5523_engine *engine)
322 {
323 	struct lp5523_chip *chip = engine_to_lp5523(engine);
324 	struct i2c_client *client = chip->client;
325 	int ret;
326 
327 	ret = lp5523_write(client, LP5523_REG_ENABLE,
328 					LP5523_CMD_RUN | LP5523_ENABLE);
329 	if (ret)
330 		goto fail;
331 
332 	ret = lp5523_set_engine_mode(engine, LP5523_CMD_RUN);
333 fail:
334 	return ret;
335 }
336 
337 static int lp5523_mux_parse(const char *buf, u16 *mux, size_t len)
338 {
339 	int i;
340 	u16 tmp_mux = 0;
341 	len = len < LP5523_LEDS ? len : LP5523_LEDS;
342 	for (i = 0; i < len; i++) {
343 		switch (buf[i]) {
344 		case '1':
345 			tmp_mux |= (1 << i);
346 			break;
347 		case '0':
348 			break;
349 		case '\n':
350 			i = len;
351 			break;
352 		default:
353 			return -1;
354 		}
355 	}
356 	*mux = tmp_mux;
357 
358 	return 0;
359 }
360 
361 static void lp5523_mux_to_array(u16 led_mux, char *array)
362 {
363 	int i, pos = 0;
364 	for (i = 0; i < LP5523_LEDS; i++)
365 		pos += sprintf(array + pos, "%x", LED_ACTIVE(led_mux, i));
366 
367 	array[pos] = '\0';
368 }
369 
370 /*--------------------------------------------------------------*/
371 /*			Sysfs interface				*/
372 /*--------------------------------------------------------------*/
373 
374 static ssize_t show_engine_leds(struct device *dev,
375 			    struct device_attribute *attr,
376 			    char *buf, int nr)
377 {
378 	struct i2c_client *client = to_i2c_client(dev);
379 	struct lp5523_chip *chip = i2c_get_clientdata(client);
380 	char mux[LP5523_LEDS + 1];
381 
382 	lp5523_mux_to_array(chip->engines[nr - 1].led_mux, mux);
383 
384 	return sprintf(buf, "%s\n", mux);
385 }
386 
387 #define show_leds(nr)							\
388 static ssize_t show_engine##nr##_leds(struct device *dev,		\
389 			    struct device_attribute *attr,		\
390 			    char *buf)					\
391 {									\
392 	return show_engine_leds(dev, attr, buf, nr);			\
393 }
394 show_leds(1)
395 show_leds(2)
396 show_leds(3)
397 
398 static ssize_t store_engine_leds(struct device *dev,
399 			     struct device_attribute *attr,
400 			     const char *buf, size_t len, int nr)
401 {
402 	struct i2c_client *client = to_i2c_client(dev);
403 	struct lp5523_chip *chip = i2c_get_clientdata(client);
404 	u16 mux = 0;
405 	ssize_t ret;
406 
407 	if (lp5523_mux_parse(buf, &mux, len))
408 		return -EINVAL;
409 
410 	mutex_lock(&chip->lock);
411 	ret = -EINVAL;
412 	if (chip->engines[nr - 1].mode != LP5523_CMD_LOAD)
413 		goto leave;
414 
415 	if (lp5523_load_mux(&chip->engines[nr - 1], mux))
416 		goto leave;
417 
418 	ret = len;
419 leave:
420 	mutex_unlock(&chip->lock);
421 	return ret;
422 }
423 
424 #define store_leds(nr)						\
425 static ssize_t store_engine##nr##_leds(struct device *dev,	\
426 			     struct device_attribute *attr,	\
427 			     const char *buf, size_t len)	\
428 {								\
429 	return store_engine_leds(dev, attr, buf, len, nr);	\
430 }
431 store_leds(1)
432 store_leds(2)
433 store_leds(3)
434 
435 static ssize_t lp5523_selftest(struct device *dev,
436 			       struct device_attribute *attr,
437 			       char *buf)
438 {
439 	struct i2c_client *client = to_i2c_client(dev);
440 	struct lp5523_chip *chip = i2c_get_clientdata(client);
441 	int i, ret, pos = 0;
442 	int led = 0;
443 	u8 status, adc, vdd;
444 
445 	mutex_lock(&chip->lock);
446 
447 	ret = lp5523_read(chip->client, LP5523_REG_STATUS, &status);
448 	if (ret < 0)
449 		goto fail;
450 
451 	/* Check that ext clock is really in use if requested */
452 	if ((chip->pdata) && (chip->pdata->clock_mode == LP5523_CLOCK_EXT))
453 		if  ((status & LP5523_EXT_CLK_USED) == 0)
454 			goto fail;
455 
456 	/* Measure VDD (i.e. VBAT) first (channel 16 corresponds to VDD) */
457 	lp5523_write(chip->client, LP5523_REG_LED_TEST_CTRL,
458 				    LP5523_EN_LEDTEST | 16);
459 	usleep_range(3000, 6000); /* ADC conversion time is typically 2.7 ms */
460 	ret = lp5523_read(chip->client, LP5523_REG_STATUS, &status);
461 	if (!(status & LP5523_LEDTEST_DONE))
462 		usleep_range(3000, 6000); /* Was not ready. Wait little bit */
463 
464 	ret |= lp5523_read(chip->client, LP5523_REG_LED_TEST_ADC, &vdd);
465 	vdd--;	/* There may be some fluctuation in measurement */
466 
467 	for (i = 0; i < LP5523_LEDS; i++) {
468 		/* Skip non-existing channels */
469 		if (chip->pdata->led_config[i].led_current == 0)
470 			continue;
471 
472 		/* Set default current */
473 		lp5523_write(chip->client,
474 			LP5523_REG_LED_CURRENT_BASE + i,
475 			chip->pdata->led_config[i].led_current);
476 
477 		lp5523_write(chip->client, LP5523_REG_LED_PWM_BASE + i, 0xff);
478 		/* let current stabilize 2 - 4ms before measurements start */
479 		usleep_range(2000, 4000);
480 		lp5523_write(chip->client,
481 			     LP5523_REG_LED_TEST_CTRL,
482 			     LP5523_EN_LEDTEST | i);
483 		/* ADC conversion time is 2.7 ms typically */
484 		usleep_range(3000, 6000);
485 		ret = lp5523_read(chip->client, LP5523_REG_STATUS, &status);
486 		if (!(status & LP5523_LEDTEST_DONE))
487 			usleep_range(3000, 6000);/* Was not ready. Wait. */
488 		ret |= lp5523_read(chip->client, LP5523_REG_LED_TEST_ADC, &adc);
489 
490 		if (adc >= vdd || adc < LP5523_ADC_SHORTCIRC_LIM)
491 			pos += sprintf(buf + pos, "LED %d FAIL\n", i);
492 
493 		lp5523_write(chip->client, LP5523_REG_LED_PWM_BASE + i, 0x00);
494 
495 		/* Restore current */
496 		lp5523_write(chip->client,
497 			LP5523_REG_LED_CURRENT_BASE + i,
498 			chip->leds[led].led_current);
499 		led++;
500 	}
501 	if (pos == 0)
502 		pos = sprintf(buf, "OK\n");
503 	goto release_lock;
504 fail:
505 	pos = sprintf(buf, "FAIL\n");
506 
507 release_lock:
508 	mutex_unlock(&chip->lock);
509 
510 	return pos;
511 }
512 
513 static void lp5523_set_brightness(struct led_classdev *cdev,
514 			     enum led_brightness brightness)
515 {
516 	struct lp5523_led *led = cdev_to_led(cdev);
517 
518 	led->brightness = (u8)brightness;
519 
520 	schedule_work(&led->brightness_work);
521 }
522 
523 static void lp5523_led_brightness_work(struct work_struct *work)
524 {
525 	struct lp5523_led *led = container_of(work,
526 					      struct lp5523_led,
527 					      brightness_work);
528 	struct lp5523_chip *chip = led_to_lp5523(led);
529 	struct i2c_client *client = chip->client;
530 
531 	mutex_lock(&chip->lock);
532 
533 	lp5523_write(client, LP5523_REG_LED_PWM_BASE + led->chan_nr,
534 		     led->brightness);
535 
536 	mutex_unlock(&chip->lock);
537 }
538 
539 static int lp5523_do_store_load(struct lp5523_engine *engine,
540 				const char *buf, size_t len)
541 {
542 	struct lp5523_chip *chip = engine_to_lp5523(engine);
543 	struct i2c_client *client = chip->client;
544 	int  ret, nrchars, offset = 0, i = 0;
545 	char c[3];
546 	unsigned cmd;
547 	u8 pattern[LP5523_PROGRAM_LENGTH] = {0};
548 
549 	while ((offset < len - 1) && (i < LP5523_PROGRAM_LENGTH)) {
550 		/* separate sscanfs because length is working only for %s */
551 		ret = sscanf(buf + offset, "%2s%n ", c, &nrchars);
552 		ret = sscanf(c, "%2x", &cmd);
553 		if (ret != 1)
554 			goto fail;
555 		pattern[i] = (u8)cmd;
556 
557 		offset += nrchars;
558 		i++;
559 	}
560 
561 	/* Each instruction is 16bit long. Check that length is even */
562 	if (i % 2)
563 		goto fail;
564 
565 	mutex_lock(&chip->lock);
566 
567 	if (engine->mode == LP5523_CMD_LOAD)
568 		ret = lp5523_load_program(engine, pattern);
569 	else
570 		ret = -EINVAL;
571 
572 	mutex_unlock(&chip->lock);
573 
574 	if (ret) {
575 		dev_err(&client->dev, "failed loading pattern\n");
576 		return ret;
577 	}
578 
579 	return len;
580 fail:
581 	dev_err(&client->dev, "wrong pattern format\n");
582 	return -EINVAL;
583 }
584 
585 static ssize_t store_engine_load(struct device *dev,
586 				     struct device_attribute *attr,
587 				     const char *buf, size_t len, int nr)
588 {
589 	struct i2c_client *client = to_i2c_client(dev);
590 	struct lp5523_chip *chip = i2c_get_clientdata(client);
591 	return lp5523_do_store_load(&chip->engines[nr - 1], buf, len);
592 }
593 
594 #define store_load(nr)							\
595 static ssize_t store_engine##nr##_load(struct device *dev,		\
596 				     struct device_attribute *attr,	\
597 				     const char *buf, size_t len)	\
598 {									\
599 	return store_engine_load(dev, attr, buf, len, nr);		\
600 }
601 store_load(1)
602 store_load(2)
603 store_load(3)
604 
605 static ssize_t show_engine_mode(struct device *dev,
606 				struct device_attribute *attr,
607 				char *buf, int nr)
608 {
609 	struct i2c_client *client = to_i2c_client(dev);
610 	struct lp5523_chip *chip = i2c_get_clientdata(client);
611 	switch (chip->engines[nr - 1].mode) {
612 	case LP5523_CMD_RUN:
613 		return sprintf(buf, "run\n");
614 	case LP5523_CMD_LOAD:
615 		return sprintf(buf, "load\n");
616 	case LP5523_CMD_DISABLED:
617 		return sprintf(buf, "disabled\n");
618 	default:
619 		return sprintf(buf, "disabled\n");
620 	}
621 }
622 
623 #define show_mode(nr)							\
624 static ssize_t show_engine##nr##_mode(struct device *dev,		\
625 				    struct device_attribute *attr,	\
626 				    char *buf)				\
627 {									\
628 	return show_engine_mode(dev, attr, buf, nr);			\
629 }
630 show_mode(1)
631 show_mode(2)
632 show_mode(3)
633 
634 static ssize_t store_engine_mode(struct device *dev,
635 				 struct device_attribute *attr,
636 				 const char *buf, size_t len, int nr)
637 {
638 	struct i2c_client *client = to_i2c_client(dev);
639 	struct lp5523_chip *chip = i2c_get_clientdata(client);
640 	struct lp5523_engine *engine = &chip->engines[nr - 1];
641 	mutex_lock(&chip->lock);
642 
643 	if (!strncmp(buf, "run", 3))
644 		lp5523_set_mode(engine, LP5523_CMD_RUN);
645 	else if (!strncmp(buf, "load", 4))
646 		lp5523_set_mode(engine, LP5523_CMD_LOAD);
647 	else if (!strncmp(buf, "disabled", 8))
648 		lp5523_set_mode(engine, LP5523_CMD_DISABLED);
649 
650 	mutex_unlock(&chip->lock);
651 	return len;
652 }
653 
654 #define store_mode(nr)							\
655 static ssize_t store_engine##nr##_mode(struct device *dev,		\
656 				     struct device_attribute *attr,	\
657 				     const char *buf, size_t len)	\
658 {									\
659 	return store_engine_mode(dev, attr, buf, len, nr);		\
660 }
661 store_mode(1)
662 store_mode(2)
663 store_mode(3)
664 
665 static ssize_t show_max_current(struct device *dev,
666 			    struct device_attribute *attr,
667 			    char *buf)
668 {
669 	struct led_classdev *led_cdev = dev_get_drvdata(dev);
670 	struct lp5523_led *led = cdev_to_led(led_cdev);
671 
672 	return sprintf(buf, "%d\n", led->max_current);
673 }
674 
675 static ssize_t show_current(struct device *dev,
676 			    struct device_attribute *attr,
677 			    char *buf)
678 {
679 	struct led_classdev *led_cdev = dev_get_drvdata(dev);
680 	struct lp5523_led *led = cdev_to_led(led_cdev);
681 
682 	return sprintf(buf, "%d\n", led->led_current);
683 }
684 
685 static ssize_t store_current(struct device *dev,
686 			     struct device_attribute *attr,
687 			     const char *buf, size_t len)
688 {
689 	struct led_classdev *led_cdev = dev_get_drvdata(dev);
690 	struct lp5523_led *led = cdev_to_led(led_cdev);
691 	struct lp5523_chip *chip = led_to_lp5523(led);
692 	ssize_t ret;
693 	unsigned long curr;
694 
695 	if (strict_strtoul(buf, 0, &curr))
696 		return -EINVAL;
697 
698 	if (curr > led->max_current)
699 		return -EINVAL;
700 
701 	mutex_lock(&chip->lock);
702 	ret = lp5523_write(chip->client,
703 			LP5523_REG_LED_CURRENT_BASE + led->chan_nr,
704 			(u8)curr);
705 	mutex_unlock(&chip->lock);
706 
707 	if (ret < 0)
708 		return ret;
709 
710 	led->led_current = (u8)curr;
711 
712 	return len;
713 }
714 
715 /* led class device attributes */
716 static DEVICE_ATTR(led_current, S_IRUGO | S_IWUSR, show_current, store_current);
717 static DEVICE_ATTR(max_current, S_IRUGO , show_max_current, NULL);
718 
719 static struct attribute *lp5523_led_attributes[] = {
720 	&dev_attr_led_current.attr,
721 	&dev_attr_max_current.attr,
722 	NULL,
723 };
724 
725 static struct attribute_group lp5523_led_attribute_group = {
726 	.attrs = lp5523_led_attributes
727 };
728 
729 /* device attributes */
730 static DEVICE_ATTR(engine1_mode, S_IRUGO | S_IWUSR,
731 		   show_engine1_mode, store_engine1_mode);
732 static DEVICE_ATTR(engine2_mode, S_IRUGO | S_IWUSR,
733 		   show_engine2_mode, store_engine2_mode);
734 static DEVICE_ATTR(engine3_mode, S_IRUGO | S_IWUSR,
735 		   show_engine3_mode, store_engine3_mode);
736 static DEVICE_ATTR(engine1_leds, S_IRUGO | S_IWUSR,
737 		   show_engine1_leds, store_engine1_leds);
738 static DEVICE_ATTR(engine2_leds, S_IRUGO | S_IWUSR,
739 		   show_engine2_leds, store_engine2_leds);
740 static DEVICE_ATTR(engine3_leds, S_IRUGO | S_IWUSR,
741 		   show_engine3_leds, store_engine3_leds);
742 static DEVICE_ATTR(engine1_load, S_IWUSR, NULL, store_engine1_load);
743 static DEVICE_ATTR(engine2_load, S_IWUSR, NULL, store_engine2_load);
744 static DEVICE_ATTR(engine3_load, S_IWUSR, NULL, store_engine3_load);
745 static DEVICE_ATTR(selftest, S_IRUGO, lp5523_selftest, NULL);
746 
747 static struct attribute *lp5523_attributes[] = {
748 	&dev_attr_engine1_mode.attr,
749 	&dev_attr_engine2_mode.attr,
750 	&dev_attr_engine3_mode.attr,
751 	&dev_attr_selftest.attr,
752 	&dev_attr_engine1_load.attr,
753 	&dev_attr_engine1_leds.attr,
754 	&dev_attr_engine2_load.attr,
755 	&dev_attr_engine2_leds.attr,
756 	&dev_attr_engine3_load.attr,
757 	&dev_attr_engine3_leds.attr,
758 };
759 
760 static const struct attribute_group lp5523_group = {
761 	.attrs = lp5523_attributes,
762 };
763 
764 static int lp5523_register_sysfs(struct i2c_client *client)
765 {
766 	struct device *dev = &client->dev;
767 	int ret;
768 
769 	ret = sysfs_create_group(&dev->kobj, &lp5523_group);
770 	if (ret < 0)
771 		return ret;
772 
773 	return 0;
774 }
775 
776 static void lp5523_unregister_sysfs(struct i2c_client *client)
777 {
778 	struct lp5523_chip *chip = i2c_get_clientdata(client);
779 	struct device *dev = &client->dev;
780 	int i;
781 
782 	sysfs_remove_group(&dev->kobj, &lp5523_group);
783 
784 	for (i = 0; i < chip->num_leds; i++)
785 		sysfs_remove_group(&chip->leds[i].cdev.dev->kobj,
786 				&lp5523_led_attribute_group);
787 }
788 
789 /*--------------------------------------------------------------*/
790 /*			Set chip operating mode			*/
791 /*--------------------------------------------------------------*/
792 static int lp5523_set_mode(struct lp5523_engine *engine, u8 mode)
793 {
794 	int ret = 0;
795 
796 	/* if in that mode already do nothing, except for run */
797 	if (mode == engine->mode && mode != LP5523_CMD_RUN)
798 		return 0;
799 
800 	if (mode == LP5523_CMD_RUN) {
801 		ret = lp5523_run_program(engine);
802 	} else if (mode == LP5523_CMD_LOAD) {
803 		lp5523_set_engine_mode(engine, LP5523_CMD_DISABLED);
804 		lp5523_set_engine_mode(engine, LP5523_CMD_LOAD);
805 	} else if (mode == LP5523_CMD_DISABLED) {
806 		lp5523_set_engine_mode(engine, LP5523_CMD_DISABLED);
807 	}
808 
809 	engine->mode = mode;
810 
811 	return ret;
812 }
813 
814 /*--------------------------------------------------------------*/
815 /*			Probe, Attach, Remove			*/
816 /*--------------------------------------------------------------*/
817 static int __init lp5523_init_engine(struct lp5523_engine *engine, int id)
818 {
819 	if (id < 1 || id > LP5523_ENGINES)
820 		return -1;
821 	engine->id = id;
822 	engine->engine_mask = LP5523_ENG_MASK_BASE >> SHIFT_MASK(id);
823 	engine->prog_page = id - 1;
824 	engine->mux_page = id + 2;
825 
826 	return 0;
827 }
828 
829 static int __devinit lp5523_init_led(struct lp5523_led *led, struct device *dev,
830 			   int chan, struct lp5523_platform_data *pdata)
831 {
832 	char name[32];
833 	int res;
834 
835 	if (chan >= LP5523_LEDS)
836 		return -EINVAL;
837 
838 	if (pdata->led_config[chan].led_current) {
839 		led->led_current = pdata->led_config[chan].led_current;
840 		led->max_current = pdata->led_config[chan].max_current;
841 		led->chan_nr = pdata->led_config[chan].chan_nr;
842 
843 		if (led->chan_nr >= LP5523_LEDS) {
844 			dev_err(dev, "Use channel numbers between 0 and %d\n",
845 				LP5523_LEDS - 1);
846 			return -EINVAL;
847 		}
848 
849 		snprintf(name, sizeof(name), "%s:channel%d",
850 			pdata->label ?: "lp5523", chan);
851 
852 		led->cdev.name = name;
853 		led->cdev.brightness_set = lp5523_set_brightness;
854 		res = led_classdev_register(dev, &led->cdev);
855 		if (res < 0) {
856 			dev_err(dev, "couldn't register led on channel %d\n",
857 				chan);
858 			return res;
859 		}
860 		res = sysfs_create_group(&led->cdev.dev->kobj,
861 				&lp5523_led_attribute_group);
862 		if (res < 0) {
863 			dev_err(dev, "couldn't register current attribute\n");
864 			led_classdev_unregister(&led->cdev);
865 			return res;
866 		}
867 	} else {
868 		led->led_current = 0;
869 	}
870 	return 0;
871 }
872 
873 static struct i2c_driver lp5523_driver;
874 
875 static int __devinit lp5523_probe(struct i2c_client *client,
876 			const struct i2c_device_id *id)
877 {
878 	struct lp5523_chip		*chip;
879 	struct lp5523_platform_data	*pdata;
880 	int ret, i, led;
881 
882 	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
883 	if (!chip)
884 		return -ENOMEM;
885 
886 	i2c_set_clientdata(client, chip);
887 	chip->client = client;
888 
889 	pdata = client->dev.platform_data;
890 
891 	if (!pdata) {
892 		dev_err(&client->dev, "no platform data\n");
893 		ret = -EINVAL;
894 		goto fail1;
895 	}
896 
897 	mutex_init(&chip->lock);
898 
899 	chip->pdata   = pdata;
900 
901 	if (pdata->setup_resources) {
902 		ret = pdata->setup_resources();
903 		if (ret < 0)
904 			goto fail1;
905 	}
906 
907 	if (pdata->enable) {
908 		pdata->enable(0);
909 		usleep_range(1000, 2000); /* Keep enable down at least 1ms */
910 		pdata->enable(1);
911 		usleep_range(1000, 2000); /* 500us abs min. */
912 	}
913 
914 	lp5523_write(client, LP5523_REG_RESET, 0xff);
915 	usleep_range(10000, 20000); /*
916 				     * Exact value is not available. 10 - 20ms
917 				     * appears to be enough for reset.
918 				     */
919 	ret = lp5523_detect(client);
920 	if (ret)
921 		goto fail2;
922 
923 	dev_info(&client->dev, "LP5523 Programmable led chip found\n");
924 
925 	/* Initialize engines */
926 	for (i = 0; i < ARRAY_SIZE(chip->engines); i++) {
927 		ret = lp5523_init_engine(&chip->engines[i], i + 1);
928 		if (ret) {
929 			dev_err(&client->dev, "error initializing engine\n");
930 			goto fail2;
931 		}
932 	}
933 	ret = lp5523_configure(client);
934 	if (ret < 0) {
935 		dev_err(&client->dev, "error configuring chip\n");
936 		goto fail2;
937 	}
938 
939 	/* Initialize leds */
940 	chip->num_channels = pdata->num_channels;
941 	chip->num_leds = 0;
942 	led = 0;
943 	for (i = 0; i < pdata->num_channels; i++) {
944 		/* Do not initialize channels that are not connected */
945 		if (pdata->led_config[i].led_current == 0)
946 			continue;
947 
948 		ret = lp5523_init_led(&chip->leds[led], &client->dev, i, pdata);
949 		if (ret) {
950 			dev_err(&client->dev, "error initializing leds\n");
951 			goto fail3;
952 		}
953 		chip->num_leds++;
954 
955 		chip->leds[led].id = led;
956 		/* Set LED current */
957 		lp5523_write(client,
958 			  LP5523_REG_LED_CURRENT_BASE + chip->leds[led].chan_nr,
959 			  chip->leds[led].led_current);
960 
961 		INIT_WORK(&(chip->leds[led].brightness_work),
962 			lp5523_led_brightness_work);
963 
964 		led++;
965 	}
966 
967 	ret = lp5523_register_sysfs(client);
968 	if (ret) {
969 		dev_err(&client->dev, "registering sysfs failed\n");
970 		goto fail3;
971 	}
972 	return ret;
973 fail3:
974 	for (i = 0; i < chip->num_leds; i++) {
975 		led_classdev_unregister(&chip->leds[i].cdev);
976 		cancel_work_sync(&chip->leds[i].brightness_work);
977 	}
978 fail2:
979 	if (pdata->enable)
980 		pdata->enable(0);
981 	if (pdata->release_resources)
982 		pdata->release_resources();
983 fail1:
984 	kfree(chip);
985 	return ret;
986 }
987 
988 static int lp5523_remove(struct i2c_client *client)
989 {
990 	struct lp5523_chip *chip = i2c_get_clientdata(client);
991 	int i;
992 
993 	lp5523_unregister_sysfs(client);
994 
995 	for (i = 0; i < chip->num_leds; i++) {
996 		led_classdev_unregister(&chip->leds[i].cdev);
997 		cancel_work_sync(&chip->leds[i].brightness_work);
998 	}
999 
1000 	if (chip->pdata->enable)
1001 		chip->pdata->enable(0);
1002 	if (chip->pdata->release_resources)
1003 		chip->pdata->release_resources();
1004 	kfree(chip);
1005 	return 0;
1006 }
1007 
1008 static const struct i2c_device_id lp5523_id[] = {
1009 	{ "lp5523", 0 },
1010 	{ }
1011 };
1012 
1013 MODULE_DEVICE_TABLE(i2c, lp5523_id);
1014 
1015 static struct i2c_driver lp5523_driver = {
1016 	.driver = {
1017 		.name	= "lp5523",
1018 	},
1019 	.probe		= lp5523_probe,
1020 	.remove		= lp5523_remove,
1021 	.id_table	= lp5523_id,
1022 };
1023 
1024 static int __init lp5523_init(void)
1025 {
1026 	int ret;
1027 
1028 	ret = i2c_add_driver(&lp5523_driver);
1029 
1030 	if (ret < 0)
1031 		printk(KERN_ALERT "Adding lp5523 driver failed\n");
1032 
1033 	return ret;
1034 }
1035 
1036 static void __exit lp5523_exit(void)
1037 {
1038 	i2c_del_driver(&lp5523_driver);
1039 }
1040 
1041 module_init(lp5523_init);
1042 module_exit(lp5523_exit);
1043 
1044 MODULE_AUTHOR("Mathias Nyman <mathias.nyman@nokia.com>");
1045 MODULE_DESCRIPTION("LP5523 LED engine");
1046 MODULE_LICENSE("GPL");
1047