xref: /openbmc/linux/drivers/leds/leds-lp5523.c (revision cfdfc14e)
1 /*
2  * lp5523.c - LP5523, LP55231 LED Driver
3  *
4  * Copyright (C) 2010 Nokia Corporation
5  * Copyright (C) 2012 Texas Instruments
6  *
7  * Contact: Samu Onkalo <samu.p.onkalo@nokia.com>
8  *          Milo(Woogyom) Kim <milo.kim@ti.com>
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License
12  * version 2 as published by the Free Software Foundation.
13  *
14  * This program is distributed in the hope that it will be useful, but
15  * WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  * General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
22  * 02110-1301 USA
23  */
24 
25 #include <linux/delay.h>
26 #include <linux/firmware.h>
27 #include <linux/i2c.h>
28 #include <linux/leds.h>
29 #include <linux/module.h>
30 #include <linux/mutex.h>
31 #include <linux/of.h>
32 #include <linux/platform_data/leds-lp55xx.h>
33 #include <linux/slab.h>
34 
35 #include "leds-lp55xx-common.h"
36 
37 #define LP5523_PROGRAM_LENGTH		32	/* bytes */
38 /* Memory is used like this:
39    0x00 engine 1 program
40    0x10 engine 2 program
41    0x20 engine 3 program
42    0x30 engine 1 muxing info
43    0x40 engine 2 muxing info
44    0x50 engine 3 muxing info
45 */
46 #define LP5523_MAX_LEDS			9
47 
48 /* Registers */
49 #define LP5523_REG_ENABLE		0x00
50 #define LP5523_REG_OP_MODE		0x01
51 #define LP5523_REG_ENABLE_LEDS_MSB	0x04
52 #define LP5523_REG_ENABLE_LEDS_LSB	0x05
53 #define LP5523_REG_LED_CTRL_BASE	0x06
54 #define LP5523_REG_LED_PWM_BASE		0x16
55 #define LP5523_REG_LED_CURRENT_BASE	0x26
56 #define LP5523_REG_CONFIG		0x36
57 #define LP5523_REG_STATUS		0x3A
58 #define LP5523_REG_RESET		0x3D
59 #define LP5523_REG_LED_TEST_CTRL	0x41
60 #define LP5523_REG_LED_TEST_ADC		0x42
61 #define LP5523_REG_MASTER_FADER_BASE	0x48
62 #define LP5523_REG_CH1_PROG_START	0x4C
63 #define LP5523_REG_CH2_PROG_START	0x4D
64 #define LP5523_REG_CH3_PROG_START	0x4E
65 #define LP5523_REG_PROG_PAGE_SEL	0x4F
66 #define LP5523_REG_PROG_MEM		0x50
67 
68 /* Bit description in registers */
69 #define LP5523_ENABLE			0x40
70 #define LP5523_AUTO_INC			0x40
71 #define LP5523_PWR_SAVE			0x20
72 #define LP5523_PWM_PWR_SAVE		0x04
73 #define LP5523_CP_AUTO			0x18
74 #define LP5523_AUTO_CLK			0x02
75 
76 #define LP5523_EN_LEDTEST		0x80
77 #define LP5523_LEDTEST_DONE		0x80
78 #define LP5523_RESET			0xFF
79 #define LP5523_ADC_SHORTCIRC_LIM	80
80 #define LP5523_EXT_CLK_USED		0x08
81 #define LP5523_ENG_STATUS_MASK		0x07
82 
83 #define LP5523_FADER_MAPPING_MASK	0xC0
84 #define LP5523_FADER_MAPPING_SHIFT	6
85 
86 /* Memory Page Selection */
87 #define LP5523_PAGE_ENG1		0
88 #define LP5523_PAGE_ENG2		1
89 #define LP5523_PAGE_ENG3		2
90 #define LP5523_PAGE_MUX1		3
91 #define LP5523_PAGE_MUX2		4
92 #define LP5523_PAGE_MUX3		5
93 
94 /* Program Memory Operations */
95 #define LP5523_MODE_ENG1_M		0x30	/* Operation Mode Register */
96 #define LP5523_MODE_ENG2_M		0x0C
97 #define LP5523_MODE_ENG3_M		0x03
98 #define LP5523_LOAD_ENG1		0x10
99 #define LP5523_LOAD_ENG2		0x04
100 #define LP5523_LOAD_ENG3		0x01
101 
102 #define LP5523_ENG1_IS_LOADING(mode)	\
103 	((mode & LP5523_MODE_ENG1_M) == LP5523_LOAD_ENG1)
104 #define LP5523_ENG2_IS_LOADING(mode)	\
105 	((mode & LP5523_MODE_ENG2_M) == LP5523_LOAD_ENG2)
106 #define LP5523_ENG3_IS_LOADING(mode)	\
107 	((mode & LP5523_MODE_ENG3_M) == LP5523_LOAD_ENG3)
108 
109 #define LP5523_EXEC_ENG1_M		0x30	/* Enable Register */
110 #define LP5523_EXEC_ENG2_M		0x0C
111 #define LP5523_EXEC_ENG3_M		0x03
112 #define LP5523_EXEC_M			0x3F
113 #define LP5523_RUN_ENG1			0x20
114 #define LP5523_RUN_ENG2			0x08
115 #define LP5523_RUN_ENG3			0x02
116 
117 #define LED_ACTIVE(mux, led)		(!!(mux & (0x0001 << led)))
118 
119 enum lp5523_chip_id {
120 	LP5523,
121 	LP55231,
122 };
123 
124 static int lp5523_init_program_engine(struct lp55xx_chip *chip);
125 
126 static inline void lp5523_wait_opmode_done(void)
127 {
128 	usleep_range(1000, 2000);
129 }
130 
131 static void lp5523_set_led_current(struct lp55xx_led *led, u8 led_current)
132 {
133 	led->led_current = led_current;
134 	lp55xx_write(led->chip, LP5523_REG_LED_CURRENT_BASE + led->chan_nr,
135 		led_current);
136 }
137 
138 static int lp5523_post_init_device(struct lp55xx_chip *chip)
139 {
140 	int ret;
141 
142 	ret = lp55xx_write(chip, LP5523_REG_ENABLE, LP5523_ENABLE);
143 	if (ret)
144 		return ret;
145 
146 	/* Chip startup time is 500 us, 1 - 2 ms gives some margin */
147 	usleep_range(1000, 2000);
148 
149 	ret = lp55xx_write(chip, LP5523_REG_CONFIG,
150 			    LP5523_AUTO_INC | LP5523_PWR_SAVE |
151 			    LP5523_CP_AUTO | LP5523_AUTO_CLK |
152 			    LP5523_PWM_PWR_SAVE);
153 	if (ret)
154 		return ret;
155 
156 	/* turn on all leds */
157 	ret = lp55xx_write(chip, LP5523_REG_ENABLE_LEDS_MSB, 0x01);
158 	if (ret)
159 		return ret;
160 
161 	ret = lp55xx_write(chip, LP5523_REG_ENABLE_LEDS_LSB, 0xff);
162 	if (ret)
163 		return ret;
164 
165 	return lp5523_init_program_engine(chip);
166 }
167 
168 static void lp5523_load_engine(struct lp55xx_chip *chip)
169 {
170 	enum lp55xx_engine_index idx = chip->engine_idx;
171 	static const u8 mask[] = {
172 		[LP55XX_ENGINE_1] = LP5523_MODE_ENG1_M,
173 		[LP55XX_ENGINE_2] = LP5523_MODE_ENG2_M,
174 		[LP55XX_ENGINE_3] = LP5523_MODE_ENG3_M,
175 	};
176 
177 	static const u8 val[] = {
178 		[LP55XX_ENGINE_1] = LP5523_LOAD_ENG1,
179 		[LP55XX_ENGINE_2] = LP5523_LOAD_ENG2,
180 		[LP55XX_ENGINE_3] = LP5523_LOAD_ENG3,
181 	};
182 
183 	lp55xx_update_bits(chip, LP5523_REG_OP_MODE, mask[idx], val[idx]);
184 
185 	lp5523_wait_opmode_done();
186 }
187 
188 static void lp5523_load_engine_and_select_page(struct lp55xx_chip *chip)
189 {
190 	enum lp55xx_engine_index idx = chip->engine_idx;
191 	static const u8 page_sel[] = {
192 		[LP55XX_ENGINE_1] = LP5523_PAGE_ENG1,
193 		[LP55XX_ENGINE_2] = LP5523_PAGE_ENG2,
194 		[LP55XX_ENGINE_3] = LP5523_PAGE_ENG3,
195 	};
196 
197 	lp5523_load_engine(chip);
198 
199 	lp55xx_write(chip, LP5523_REG_PROG_PAGE_SEL, page_sel[idx]);
200 }
201 
202 static void lp5523_stop_all_engines(struct lp55xx_chip *chip)
203 {
204 	lp55xx_write(chip, LP5523_REG_OP_MODE, 0);
205 	lp5523_wait_opmode_done();
206 }
207 
208 static void lp5523_stop_engine(struct lp55xx_chip *chip)
209 {
210 	enum lp55xx_engine_index idx = chip->engine_idx;
211 	static const u8 mask[] = {
212 		[LP55XX_ENGINE_1] = LP5523_MODE_ENG1_M,
213 		[LP55XX_ENGINE_2] = LP5523_MODE_ENG2_M,
214 		[LP55XX_ENGINE_3] = LP5523_MODE_ENG3_M,
215 	};
216 
217 	lp55xx_update_bits(chip, LP5523_REG_OP_MODE, mask[idx], 0);
218 
219 	lp5523_wait_opmode_done();
220 }
221 
222 static void lp5523_turn_off_channels(struct lp55xx_chip *chip)
223 {
224 	int i;
225 
226 	for (i = 0; i < LP5523_MAX_LEDS; i++)
227 		lp55xx_write(chip, LP5523_REG_LED_PWM_BASE + i, 0);
228 }
229 
230 static void lp5523_run_engine(struct lp55xx_chip *chip, bool start)
231 {
232 	int ret;
233 	u8 mode;
234 	u8 exec;
235 
236 	/* stop engine */
237 	if (!start) {
238 		lp5523_stop_engine(chip);
239 		lp5523_turn_off_channels(chip);
240 		return;
241 	}
242 
243 	/*
244 	 * To run the engine,
245 	 * operation mode and enable register should updated at the same time
246 	 */
247 
248 	ret = lp55xx_read(chip, LP5523_REG_OP_MODE, &mode);
249 	if (ret)
250 		return;
251 
252 	ret = lp55xx_read(chip, LP5523_REG_ENABLE, &exec);
253 	if (ret)
254 		return;
255 
256 	/* change operation mode to RUN only when each engine is loading */
257 	if (LP5523_ENG1_IS_LOADING(mode)) {
258 		mode = (mode & ~LP5523_MODE_ENG1_M) | LP5523_RUN_ENG1;
259 		exec = (exec & ~LP5523_EXEC_ENG1_M) | LP5523_RUN_ENG1;
260 	}
261 
262 	if (LP5523_ENG2_IS_LOADING(mode)) {
263 		mode = (mode & ~LP5523_MODE_ENG2_M) | LP5523_RUN_ENG2;
264 		exec = (exec & ~LP5523_EXEC_ENG2_M) | LP5523_RUN_ENG2;
265 	}
266 
267 	if (LP5523_ENG3_IS_LOADING(mode)) {
268 		mode = (mode & ~LP5523_MODE_ENG3_M) | LP5523_RUN_ENG3;
269 		exec = (exec & ~LP5523_EXEC_ENG3_M) | LP5523_RUN_ENG3;
270 	}
271 
272 	lp55xx_write(chip, LP5523_REG_OP_MODE, mode);
273 	lp5523_wait_opmode_done();
274 
275 	lp55xx_update_bits(chip, LP5523_REG_ENABLE, LP5523_EXEC_M, exec);
276 }
277 
278 static int lp5523_init_program_engine(struct lp55xx_chip *chip)
279 {
280 	int i;
281 	int j;
282 	int ret;
283 	u8 status;
284 	/* one pattern per engine setting LED MUX start and stop addresses */
285 	static const u8 pattern[][LP5523_PROGRAM_LENGTH] =  {
286 		{ 0x9c, 0x30, 0x9c, 0xb0, 0x9d, 0x80, 0xd8, 0x00, 0},
287 		{ 0x9c, 0x40, 0x9c, 0xc0, 0x9d, 0x80, 0xd8, 0x00, 0},
288 		{ 0x9c, 0x50, 0x9c, 0xd0, 0x9d, 0x80, 0xd8, 0x00, 0},
289 	};
290 
291 	/* hardcode 32 bytes of memory for each engine from program memory */
292 	ret = lp55xx_write(chip, LP5523_REG_CH1_PROG_START, 0x00);
293 	if (ret)
294 		return ret;
295 
296 	ret = lp55xx_write(chip, LP5523_REG_CH2_PROG_START, 0x10);
297 	if (ret)
298 		return ret;
299 
300 	ret = lp55xx_write(chip, LP5523_REG_CH3_PROG_START, 0x20);
301 	if (ret)
302 		return ret;
303 
304 	/* write LED MUX address space for each engine */
305 	for (i = LP55XX_ENGINE_1; i <= LP55XX_ENGINE_3; i++) {
306 		chip->engine_idx = i;
307 		lp5523_load_engine_and_select_page(chip);
308 
309 		for (j = 0; j < LP5523_PROGRAM_LENGTH; j++) {
310 			ret = lp55xx_write(chip, LP5523_REG_PROG_MEM + j,
311 					pattern[i - 1][j]);
312 			if (ret)
313 				goto out;
314 		}
315 	}
316 
317 	lp5523_run_engine(chip, true);
318 
319 	/* Let the programs run for couple of ms and check the engine status */
320 	usleep_range(3000, 6000);
321 	lp55xx_read(chip, LP5523_REG_STATUS, &status);
322 	status &= LP5523_ENG_STATUS_MASK;
323 
324 	if (status != LP5523_ENG_STATUS_MASK) {
325 		dev_err(&chip->cl->dev,
326 			"could not configure LED engine, status = 0x%.2x\n",
327 			status);
328 		ret = -1;
329 	}
330 
331 out:
332 	lp5523_stop_all_engines(chip);
333 	return ret;
334 }
335 
336 static int lp5523_update_program_memory(struct lp55xx_chip *chip,
337 					const u8 *data, size_t size)
338 {
339 	u8 pattern[LP5523_PROGRAM_LENGTH] = {0};
340 	unsigned cmd;
341 	char c[3];
342 	int nrchars;
343 	int ret;
344 	int offset = 0;
345 	int i = 0;
346 
347 	while ((offset < size - 1) && (i < LP5523_PROGRAM_LENGTH)) {
348 		/* separate sscanfs because length is working only for %s */
349 		ret = sscanf(data + offset, "%2s%n ", c, &nrchars);
350 		if (ret != 1)
351 			goto err;
352 
353 		ret = sscanf(c, "%2x", &cmd);
354 		if (ret != 1)
355 			goto err;
356 
357 		pattern[i] = (u8)cmd;
358 		offset += nrchars;
359 		i++;
360 	}
361 
362 	/* Each instruction is 16bit long. Check that length is even */
363 	if (i % 2)
364 		goto err;
365 
366 	for (i = 0; i < LP5523_PROGRAM_LENGTH; i++) {
367 		ret = lp55xx_write(chip, LP5523_REG_PROG_MEM + i, pattern[i]);
368 		if (ret)
369 			return -EINVAL;
370 	}
371 
372 	return size;
373 
374 err:
375 	dev_err(&chip->cl->dev, "wrong pattern format\n");
376 	return -EINVAL;
377 }
378 
379 static void lp5523_firmware_loaded(struct lp55xx_chip *chip)
380 {
381 	const struct firmware *fw = chip->fw;
382 
383 	if (fw->size > LP5523_PROGRAM_LENGTH) {
384 		dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n",
385 			fw->size);
386 		return;
387 	}
388 
389 	/*
390 	 * Program memory sequence
391 	 *  1) set engine mode to "LOAD"
392 	 *  2) write firmware data into program memory
393 	 */
394 
395 	lp5523_load_engine_and_select_page(chip);
396 	lp5523_update_program_memory(chip, fw->data, fw->size);
397 }
398 
399 static ssize_t show_engine_mode(struct device *dev,
400 				struct device_attribute *attr,
401 				char *buf, int nr)
402 {
403 	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
404 	struct lp55xx_chip *chip = led->chip;
405 	enum lp55xx_engine_mode mode = chip->engines[nr - 1].mode;
406 
407 	switch (mode) {
408 	case LP55XX_ENGINE_RUN:
409 		return sprintf(buf, "run\n");
410 	case LP55XX_ENGINE_LOAD:
411 		return sprintf(buf, "load\n");
412 	case LP55XX_ENGINE_DISABLED:
413 	default:
414 		return sprintf(buf, "disabled\n");
415 	}
416 }
417 show_mode(1)
418 show_mode(2)
419 show_mode(3)
420 
421 static ssize_t store_engine_mode(struct device *dev,
422 				 struct device_attribute *attr,
423 				 const char *buf, size_t len, int nr)
424 {
425 	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
426 	struct lp55xx_chip *chip = led->chip;
427 	struct lp55xx_engine *engine = &chip->engines[nr - 1];
428 
429 	mutex_lock(&chip->lock);
430 
431 	chip->engine_idx = nr;
432 
433 	if (!strncmp(buf, "run", 3)) {
434 		lp5523_run_engine(chip, true);
435 		engine->mode = LP55XX_ENGINE_RUN;
436 	} else if (!strncmp(buf, "load", 4)) {
437 		lp5523_stop_engine(chip);
438 		lp5523_load_engine(chip);
439 		engine->mode = LP55XX_ENGINE_LOAD;
440 	} else if (!strncmp(buf, "disabled", 8)) {
441 		lp5523_stop_engine(chip);
442 		engine->mode = LP55XX_ENGINE_DISABLED;
443 	}
444 
445 	mutex_unlock(&chip->lock);
446 
447 	return len;
448 }
449 store_mode(1)
450 store_mode(2)
451 store_mode(3)
452 
453 static int lp5523_mux_parse(const char *buf, u16 *mux, size_t len)
454 {
455 	u16 tmp_mux = 0;
456 	int i;
457 
458 	len = min_t(int, len, LP5523_MAX_LEDS);
459 
460 	for (i = 0; i < len; i++) {
461 		switch (buf[i]) {
462 		case '1':
463 			tmp_mux |= (1 << i);
464 			break;
465 		case '0':
466 			break;
467 		case '\n':
468 			i = len;
469 			break;
470 		default:
471 			return -1;
472 		}
473 	}
474 	*mux = tmp_mux;
475 
476 	return 0;
477 }
478 
479 static void lp5523_mux_to_array(u16 led_mux, char *array)
480 {
481 	int i, pos = 0;
482 	for (i = 0; i < LP5523_MAX_LEDS; i++)
483 		pos += sprintf(array + pos, "%x", LED_ACTIVE(led_mux, i));
484 
485 	array[pos] = '\0';
486 }
487 
488 static ssize_t show_engine_leds(struct device *dev,
489 			    struct device_attribute *attr,
490 			    char *buf, int nr)
491 {
492 	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
493 	struct lp55xx_chip *chip = led->chip;
494 	char mux[LP5523_MAX_LEDS + 1];
495 
496 	lp5523_mux_to_array(chip->engines[nr - 1].led_mux, mux);
497 
498 	return sprintf(buf, "%s\n", mux);
499 }
500 show_leds(1)
501 show_leds(2)
502 show_leds(3)
503 
504 static int lp5523_load_mux(struct lp55xx_chip *chip, u16 mux, int nr)
505 {
506 	struct lp55xx_engine *engine = &chip->engines[nr - 1];
507 	int ret;
508 	static const u8 mux_page[] = {
509 		[LP55XX_ENGINE_1] = LP5523_PAGE_MUX1,
510 		[LP55XX_ENGINE_2] = LP5523_PAGE_MUX2,
511 		[LP55XX_ENGINE_3] = LP5523_PAGE_MUX3,
512 	};
513 
514 	lp5523_load_engine(chip);
515 
516 	ret = lp55xx_write(chip, LP5523_REG_PROG_PAGE_SEL, mux_page[nr]);
517 	if (ret)
518 		return ret;
519 
520 	ret = lp55xx_write(chip, LP5523_REG_PROG_MEM , (u8)(mux >> 8));
521 	if (ret)
522 		return ret;
523 
524 	ret = lp55xx_write(chip, LP5523_REG_PROG_MEM + 1, (u8)(mux));
525 	if (ret)
526 		return ret;
527 
528 	engine->led_mux = mux;
529 	return 0;
530 }
531 
532 static ssize_t store_engine_leds(struct device *dev,
533 			     struct device_attribute *attr,
534 			     const char *buf, size_t len, int nr)
535 {
536 	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
537 	struct lp55xx_chip *chip = led->chip;
538 	struct lp55xx_engine *engine = &chip->engines[nr - 1];
539 	u16 mux = 0;
540 	ssize_t ret;
541 
542 	if (lp5523_mux_parse(buf, &mux, len))
543 		return -EINVAL;
544 
545 	mutex_lock(&chip->lock);
546 
547 	chip->engine_idx = nr;
548 	ret = -EINVAL;
549 
550 	if (engine->mode != LP55XX_ENGINE_LOAD)
551 		goto leave;
552 
553 	if (lp5523_load_mux(chip, mux, nr))
554 		goto leave;
555 
556 	ret = len;
557 leave:
558 	mutex_unlock(&chip->lock);
559 	return ret;
560 }
561 store_leds(1)
562 store_leds(2)
563 store_leds(3)
564 
565 static ssize_t store_engine_load(struct device *dev,
566 			     struct device_attribute *attr,
567 			     const char *buf, size_t len, int nr)
568 {
569 	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
570 	struct lp55xx_chip *chip = led->chip;
571 	int ret;
572 
573 	mutex_lock(&chip->lock);
574 
575 	chip->engine_idx = nr;
576 	lp5523_load_engine_and_select_page(chip);
577 	ret = lp5523_update_program_memory(chip, buf, len);
578 
579 	mutex_unlock(&chip->lock);
580 
581 	return ret;
582 }
583 store_load(1)
584 store_load(2)
585 store_load(3)
586 
587 static ssize_t lp5523_selftest(struct device *dev,
588 			       struct device_attribute *attr,
589 			       char *buf)
590 {
591 	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
592 	struct lp55xx_chip *chip = led->chip;
593 	struct lp55xx_platform_data *pdata = chip->pdata;
594 	int i, ret, pos = 0;
595 	u8 status, adc, vdd;
596 
597 	mutex_lock(&chip->lock);
598 
599 	ret = lp55xx_read(chip, LP5523_REG_STATUS, &status);
600 	if (ret < 0)
601 		goto fail;
602 
603 	/* Check that ext clock is really in use if requested */
604 	if (pdata->clock_mode == LP55XX_CLOCK_EXT) {
605 		if  ((status & LP5523_EXT_CLK_USED) == 0)
606 			goto fail;
607 	}
608 
609 	/* Measure VDD (i.e. VBAT) first (channel 16 corresponds to VDD) */
610 	lp55xx_write(chip, LP5523_REG_LED_TEST_CTRL, LP5523_EN_LEDTEST | 16);
611 	usleep_range(3000, 6000); /* ADC conversion time is typically 2.7 ms */
612 	ret = lp55xx_read(chip, LP5523_REG_STATUS, &status);
613 	if (ret < 0)
614 		goto fail;
615 
616 	if (!(status & LP5523_LEDTEST_DONE))
617 		usleep_range(3000, 6000); /* Was not ready. Wait little bit */
618 
619 	ret = lp55xx_read(chip, LP5523_REG_LED_TEST_ADC, &vdd);
620 	if (ret < 0)
621 		goto fail;
622 
623 	vdd--;	/* There may be some fluctuation in measurement */
624 
625 	for (i = 0; i < LP5523_MAX_LEDS; i++) {
626 		/* Skip non-existing channels */
627 		if (pdata->led_config[i].led_current == 0)
628 			continue;
629 
630 		/* Set default current */
631 		lp55xx_write(chip, LP5523_REG_LED_CURRENT_BASE + i,
632 			pdata->led_config[i].led_current);
633 
634 		lp55xx_write(chip, LP5523_REG_LED_PWM_BASE + i, 0xff);
635 		/* let current stabilize 2 - 4ms before measurements start */
636 		usleep_range(2000, 4000);
637 		lp55xx_write(chip, LP5523_REG_LED_TEST_CTRL,
638 			     LP5523_EN_LEDTEST | i);
639 		/* ADC conversion time is 2.7 ms typically */
640 		usleep_range(3000, 6000);
641 		ret = lp55xx_read(chip, LP5523_REG_STATUS, &status);
642 		if (ret < 0)
643 			goto fail;
644 
645 		if (!(status & LP5523_LEDTEST_DONE))
646 			usleep_range(3000, 6000);/* Was not ready. Wait. */
647 
648 		ret = lp55xx_read(chip, LP5523_REG_LED_TEST_ADC, &adc);
649 		if (ret < 0)
650 			goto fail;
651 
652 		if (adc >= vdd || adc < LP5523_ADC_SHORTCIRC_LIM)
653 			pos += sprintf(buf + pos, "LED %d FAIL\n", i);
654 
655 		lp55xx_write(chip, LP5523_REG_LED_PWM_BASE + i, 0x00);
656 
657 		/* Restore current */
658 		lp55xx_write(chip, LP5523_REG_LED_CURRENT_BASE + i,
659 			led->led_current);
660 		led++;
661 	}
662 	if (pos == 0)
663 		pos = sprintf(buf, "OK\n");
664 	goto release_lock;
665 fail:
666 	pos = sprintf(buf, "FAIL\n");
667 
668 release_lock:
669 	mutex_unlock(&chip->lock);
670 
671 	return pos;
672 }
673 
674 #define show_fader(nr)						\
675 static ssize_t show_master_fader##nr(struct device *dev,	\
676 			    struct device_attribute *attr,	\
677 			    char *buf)				\
678 {								\
679 	return show_master_fader(dev, attr, buf, nr);		\
680 }
681 
682 #define store_fader(nr)						\
683 static ssize_t store_master_fader##nr(struct device *dev,	\
684 			     struct device_attribute *attr,	\
685 			     const char *buf, size_t len)	\
686 {								\
687 	return store_master_fader(dev, attr, buf, len, nr);	\
688 }
689 
690 static ssize_t show_master_fader(struct device *dev,
691 				 struct device_attribute *attr,
692 				 char *buf, int nr)
693 {
694 	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
695 	struct lp55xx_chip *chip = led->chip;
696 	int ret;
697 	u8 val;
698 
699 	mutex_lock(&chip->lock);
700 	ret = lp55xx_read(chip, LP5523_REG_MASTER_FADER_BASE + nr - 1, &val);
701 	mutex_unlock(&chip->lock);
702 
703 	if (ret == 0)
704 		ret = sprintf(buf, "%u\n", val);
705 
706 	return ret;
707 }
708 show_fader(1)
709 show_fader(2)
710 show_fader(3)
711 
712 static ssize_t store_master_fader(struct device *dev,
713 				  struct device_attribute *attr,
714 				  const char *buf, size_t len, int nr)
715 {
716 	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
717 	struct lp55xx_chip *chip = led->chip;
718 	int ret;
719 	unsigned long val;
720 
721 	if (kstrtoul(buf, 0, &val))
722 		return -EINVAL;
723 
724 	if (val > 0xff)
725 		return -EINVAL;
726 
727 	mutex_lock(&chip->lock);
728 	ret = lp55xx_write(chip, LP5523_REG_MASTER_FADER_BASE + nr - 1,
729 			   (u8)val);
730 	mutex_unlock(&chip->lock);
731 
732 	if (ret == 0)
733 		ret = len;
734 
735 	return ret;
736 }
737 store_fader(1)
738 store_fader(2)
739 store_fader(3)
740 
741 static ssize_t show_master_fader_leds(struct device *dev,
742 				      struct device_attribute *attr,
743 				      char *buf)
744 {
745 	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
746 	struct lp55xx_chip *chip = led->chip;
747 	int i, ret, pos = 0;
748 	u8 val;
749 
750 	mutex_lock(&chip->lock);
751 
752 	for (i = 0; i < LP5523_MAX_LEDS; i++) {
753 		ret = lp55xx_read(chip, LP5523_REG_LED_CTRL_BASE + i, &val);
754 		if (ret)
755 			goto leave;
756 
757 		val = (val & LP5523_FADER_MAPPING_MASK)
758 			>> LP5523_FADER_MAPPING_SHIFT;
759 		if (val > 3) {
760 			ret = -EINVAL;
761 			goto leave;
762 		}
763 		buf[pos++] = val + '0';
764 	}
765 	buf[pos++] = '\n';
766 	ret = pos;
767 leave:
768 	mutex_unlock(&chip->lock);
769 	return ret;
770 }
771 
772 static ssize_t store_master_fader_leds(struct device *dev,
773 				       struct device_attribute *attr,
774 				       const char *buf, size_t len)
775 {
776 	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
777 	struct lp55xx_chip *chip = led->chip;
778 	int i, n, ret;
779 	u8 val;
780 
781 	n = min_t(int, len, LP5523_MAX_LEDS);
782 
783 	mutex_lock(&chip->lock);
784 
785 	for (i = 0; i < n; i++) {
786 		if (buf[i] >= '0' && buf[i] <= '3') {
787 			val = (buf[i] - '0') << LP5523_FADER_MAPPING_SHIFT;
788 			ret = lp55xx_update_bits(chip,
789 						 LP5523_REG_LED_CTRL_BASE + i,
790 						 LP5523_FADER_MAPPING_MASK,
791 						 val);
792 			if (ret)
793 				goto leave;
794 		} else {
795 			ret = -EINVAL;
796 			goto leave;
797 		}
798 	}
799 	ret = len;
800 leave:
801 	mutex_unlock(&chip->lock);
802 	return ret;
803 }
804 
805 static int lp5523_led_brightness(struct lp55xx_led *led)
806 {
807 	struct lp55xx_chip *chip = led->chip;
808 	int ret;
809 
810 	mutex_lock(&chip->lock);
811 	ret = lp55xx_write(chip, LP5523_REG_LED_PWM_BASE + led->chan_nr,
812 		     led->brightness);
813 	mutex_unlock(&chip->lock);
814 	return ret;
815 }
816 
817 static LP55XX_DEV_ATTR_RW(engine1_mode, show_engine1_mode, store_engine1_mode);
818 static LP55XX_DEV_ATTR_RW(engine2_mode, show_engine2_mode, store_engine2_mode);
819 static LP55XX_DEV_ATTR_RW(engine3_mode, show_engine3_mode, store_engine3_mode);
820 static LP55XX_DEV_ATTR_RW(engine1_leds, show_engine1_leds, store_engine1_leds);
821 static LP55XX_DEV_ATTR_RW(engine2_leds, show_engine2_leds, store_engine2_leds);
822 static LP55XX_DEV_ATTR_RW(engine3_leds, show_engine3_leds, store_engine3_leds);
823 static LP55XX_DEV_ATTR_WO(engine1_load, store_engine1_load);
824 static LP55XX_DEV_ATTR_WO(engine2_load, store_engine2_load);
825 static LP55XX_DEV_ATTR_WO(engine3_load, store_engine3_load);
826 static LP55XX_DEV_ATTR_RO(selftest, lp5523_selftest);
827 static LP55XX_DEV_ATTR_RW(master_fader1, show_master_fader1,
828 			  store_master_fader1);
829 static LP55XX_DEV_ATTR_RW(master_fader2, show_master_fader2,
830 			  store_master_fader2);
831 static LP55XX_DEV_ATTR_RW(master_fader3, show_master_fader3,
832 			  store_master_fader3);
833 static LP55XX_DEV_ATTR_RW(master_fader_leds, show_master_fader_leds,
834 			  store_master_fader_leds);
835 
836 static struct attribute *lp5523_attributes[] = {
837 	&dev_attr_engine1_mode.attr,
838 	&dev_attr_engine2_mode.attr,
839 	&dev_attr_engine3_mode.attr,
840 	&dev_attr_engine1_load.attr,
841 	&dev_attr_engine2_load.attr,
842 	&dev_attr_engine3_load.attr,
843 	&dev_attr_engine1_leds.attr,
844 	&dev_attr_engine2_leds.attr,
845 	&dev_attr_engine3_leds.attr,
846 	&dev_attr_selftest.attr,
847 	&dev_attr_master_fader1.attr,
848 	&dev_attr_master_fader2.attr,
849 	&dev_attr_master_fader3.attr,
850 	&dev_attr_master_fader_leds.attr,
851 	NULL,
852 };
853 
854 static const struct attribute_group lp5523_group = {
855 	.attrs = lp5523_attributes,
856 };
857 
858 /* Chip specific configurations */
859 static struct lp55xx_device_config lp5523_cfg = {
860 	.reset = {
861 		.addr = LP5523_REG_RESET,
862 		.val  = LP5523_RESET,
863 	},
864 	.enable = {
865 		.addr = LP5523_REG_ENABLE,
866 		.val  = LP5523_ENABLE,
867 	},
868 	.max_channel  = LP5523_MAX_LEDS,
869 	.post_init_device   = lp5523_post_init_device,
870 	.brightness_fn      = lp5523_led_brightness,
871 	.set_led_current    = lp5523_set_led_current,
872 	.firmware_cb        = lp5523_firmware_loaded,
873 	.run_engine         = lp5523_run_engine,
874 	.dev_attr_group     = &lp5523_group,
875 };
876 
877 static int lp5523_probe(struct i2c_client *client,
878 			const struct i2c_device_id *id)
879 {
880 	int ret;
881 	struct lp55xx_chip *chip;
882 	struct lp55xx_led *led;
883 	struct lp55xx_platform_data *pdata = dev_get_platdata(&client->dev);
884 	struct device_node *np = client->dev.of_node;
885 
886 	if (!pdata) {
887 		if (np) {
888 			pdata = lp55xx_of_populate_pdata(&client->dev, np);
889 			if (IS_ERR(pdata))
890 				return PTR_ERR(pdata);
891 		} else {
892 			dev_err(&client->dev, "no platform data\n");
893 			return -EINVAL;
894 		}
895 	}
896 
897 	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
898 	if (!chip)
899 		return -ENOMEM;
900 
901 	led = devm_kcalloc(&client->dev,
902 			pdata->num_channels, sizeof(*led), GFP_KERNEL);
903 	if (!led)
904 		return -ENOMEM;
905 
906 	chip->cl = client;
907 	chip->pdata = pdata;
908 	chip->cfg = &lp5523_cfg;
909 
910 	mutex_init(&chip->lock);
911 
912 	i2c_set_clientdata(client, led);
913 
914 	ret = lp55xx_init_device(chip);
915 	if (ret)
916 		goto err_init;
917 
918 	dev_info(&client->dev, "%s Programmable led chip found\n", id->name);
919 
920 	ret = lp55xx_register_leds(led, chip);
921 	if (ret)
922 		goto err_register_leds;
923 
924 	ret = lp55xx_register_sysfs(chip);
925 	if (ret) {
926 		dev_err(&client->dev, "registering sysfs failed\n");
927 		goto err_register_sysfs;
928 	}
929 
930 	return 0;
931 
932 err_register_sysfs:
933 	lp55xx_unregister_leds(led, chip);
934 err_register_leds:
935 	lp55xx_deinit_device(chip);
936 err_init:
937 	return ret;
938 }
939 
940 static int lp5523_remove(struct i2c_client *client)
941 {
942 	struct lp55xx_led *led = i2c_get_clientdata(client);
943 	struct lp55xx_chip *chip = led->chip;
944 
945 	lp5523_stop_all_engines(chip);
946 	lp55xx_unregister_sysfs(chip);
947 	lp55xx_unregister_leds(led, chip);
948 	lp55xx_deinit_device(chip);
949 
950 	return 0;
951 }
952 
953 static const struct i2c_device_id lp5523_id[] = {
954 	{ "lp5523",  LP5523 },
955 	{ "lp55231", LP55231 },
956 	{ }
957 };
958 
959 MODULE_DEVICE_TABLE(i2c, lp5523_id);
960 
961 #ifdef CONFIG_OF
962 static const struct of_device_id of_lp5523_leds_match[] = {
963 	{ .compatible = "national,lp5523", },
964 	{ .compatible = "ti,lp55231", },
965 	{},
966 };
967 
968 MODULE_DEVICE_TABLE(of, of_lp5523_leds_match);
969 #endif
970 
971 static struct i2c_driver lp5523_driver = {
972 	.driver = {
973 		.name	= "lp5523x",
974 		.of_match_table = of_match_ptr(of_lp5523_leds_match),
975 	},
976 	.probe		= lp5523_probe,
977 	.remove		= lp5523_remove,
978 	.id_table	= lp5523_id,
979 };
980 
981 module_i2c_driver(lp5523_driver);
982 
983 MODULE_AUTHOR("Mathias Nyman <mathias.nyman@nokia.com>");
984 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
985 MODULE_DESCRIPTION("LP5523 LED engine");
986 MODULE_LICENSE("GPL");
987