xref: /openbmc/linux/drivers/leds/leds-lp5523.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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 	const struct attribute_group *attributes;
109 	int		id;
110 	u8		mode;
111 	u8		prog_page;
112 	u8		mux_page;
113 	u16		led_mux;
114 	u8		engine_mask;
115 };
116 
117 struct lp5523_led {
118 	int			id;
119 	u8			chan_nr;
120 	u8			led_current;
121 	u8			max_current;
122 	struct led_classdev     cdev;
123 	struct work_struct	brightness_work;
124 	u8			brightness;
125 };
126 
127 struct lp5523_chip {
128 	struct mutex		lock; /* Serialize control */
129 	struct i2c_client	*client;
130 	struct lp5523_engine	engines[LP5523_ENGINES];
131 	struct lp5523_led	leds[LP5523_LEDS];
132 	struct lp5523_platform_data *pdata;
133 	u8			num_channels;
134 	u8			num_leds;
135 };
136 
137 static inline struct lp5523_led *cdev_to_led(struct led_classdev *cdev)
138 {
139 	return container_of(cdev, struct lp5523_led, cdev);
140 }
141 
142 static inline struct lp5523_chip *engine_to_lp5523(struct lp5523_engine *engine)
143 {
144 	return container_of(engine, struct lp5523_chip,
145 			    engines[engine->id - 1]);
146 }
147 
148 static inline struct lp5523_chip *led_to_lp5523(struct lp5523_led *led)
149 {
150 	return container_of(led, struct lp5523_chip,
151 			    leds[led->id]);
152 }
153 
154 static int lp5523_set_mode(struct lp5523_engine *engine, u8 mode);
155 static int lp5523_set_engine_mode(struct lp5523_engine *engine, u8 mode);
156 static int lp5523_load_program(struct lp5523_engine *engine, u8 *pattern);
157 
158 static void lp5523_led_brightness_work(struct work_struct *work);
159 
160 static int lp5523_write(struct i2c_client *client, u8 reg, u8 value)
161 {
162 	return i2c_smbus_write_byte_data(client, reg, value);
163 }
164 
165 static int lp5523_read(struct i2c_client *client, u8 reg, u8 *buf)
166 {
167 	s32 ret = i2c_smbus_read_byte_data(client, reg);
168 
169 	if (ret < 0)
170 		return -EIO;
171 
172 	*buf = ret;
173 	return 0;
174 }
175 
176 static int lp5523_detect(struct i2c_client *client)
177 {
178 	int ret;
179 	u8 buf;
180 
181 	ret = lp5523_write(client, LP5523_REG_ENABLE, 0x40);
182 	if (ret)
183 		return ret;
184 	ret = lp5523_read(client, LP5523_REG_ENABLE, &buf);
185 	if (ret)
186 		return ret;
187 	if (buf == 0x40)
188 		return 0;
189 	else
190 		return -ENODEV;
191 }
192 
193 static int lp5523_configure(struct i2c_client *client)
194 {
195 	struct lp5523_chip *chip = i2c_get_clientdata(client);
196 	int ret = 0;
197 	u8 status;
198 
199 	/* one pattern per engine setting led mux start and stop addresses */
200 	u8 pattern[][LP5523_PROGRAM_LENGTH] =  {
201 		{ 0x9c, 0x30, 0x9c, 0xb0, 0x9d, 0x80, 0xd8, 0x00, 0},
202 		{ 0x9c, 0x40, 0x9c, 0xc0, 0x9d, 0x80, 0xd8, 0x00, 0},
203 		{ 0x9c, 0x50, 0x9c, 0xd0, 0x9d, 0x80, 0xd8, 0x00, 0},
204 	};
205 
206 	ret |= lp5523_write(client, LP5523_REG_ENABLE, LP5523_ENABLE);
207 	/* Chip startup time is 500 us, 1 - 2 ms gives some margin */
208 	usleep_range(1000, 2000);
209 
210 	ret |= lp5523_write(client, LP5523_REG_CONFIG,
211 			    LP5523_AUTO_INC | LP5523_PWR_SAVE |
212 			    LP5523_CP_AUTO | LP5523_AUTO_CLK |
213 			    LP5523_PWM_PWR_SAVE);
214 
215 	/* turn on all leds */
216 	ret |= lp5523_write(client, LP5523_REG_ENABLE_LEDS_MSB, 0x01);
217 	ret |= lp5523_write(client, LP5523_REG_ENABLE_LEDS_LSB, 0xff);
218 
219 	/* hardcode 32 bytes of memory for each engine from program memory */
220 	ret |= lp5523_write(client, LP5523_REG_CH1_PROG_START, 0x00);
221 	ret |= lp5523_write(client, LP5523_REG_CH2_PROG_START, 0x10);
222 	ret |= lp5523_write(client, LP5523_REG_CH3_PROG_START, 0x20);
223 
224 	/* write led mux address space for each channel */
225 	ret |= lp5523_load_program(&chip->engines[0], pattern[0]);
226 	ret |= lp5523_load_program(&chip->engines[1], pattern[1]);
227 	ret |= lp5523_load_program(&chip->engines[2], pattern[2]);
228 
229 	if (ret) {
230 		dev_err(&client->dev, "could not load mux programs\n");
231 		return -1;
232 	}
233 
234 	/* set all engines exec state and mode to run 00101010 */
235 	ret |= lp5523_write(client, LP5523_REG_ENABLE,
236 			    (LP5523_CMD_RUN | LP5523_ENABLE));
237 
238 	ret |= lp5523_write(client, LP5523_REG_OP_MODE, LP5523_CMD_RUN);
239 
240 	if (ret) {
241 		dev_err(&client->dev, "could not start mux programs\n");
242 		return -1;
243 	}
244 
245 	/* Let the programs run for couple of ms and check the engine status */
246 	usleep_range(3000, 6000);
247 	lp5523_read(client, LP5523_REG_STATUS, &status);
248 	status &= LP5523_ENG_STATUS_MASK;
249 
250 	if (status == LP5523_ENG_STATUS_MASK) {
251 		dev_dbg(&client->dev, "all engines configured\n");
252 	} else {
253 		dev_info(&client->dev, "status == %x\n", status);
254 		dev_err(&client->dev, "cound not configure LED engine\n");
255 		return -1;
256 	}
257 
258 	dev_info(&client->dev, "disabling engines\n");
259 
260 	ret |= lp5523_write(client, LP5523_REG_OP_MODE, LP5523_CMD_DISABLED);
261 
262 	return ret;
263 }
264 
265 static int lp5523_set_engine_mode(struct lp5523_engine *engine, u8 mode)
266 {
267 	struct lp5523_chip *chip = engine_to_lp5523(engine);
268 	struct i2c_client *client = chip->client;
269 	int ret;
270 	u8 engine_state;
271 
272 	ret = lp5523_read(client, LP5523_REG_OP_MODE, &engine_state);
273 	if (ret)
274 		goto fail;
275 
276 	engine_state &= ~(engine->engine_mask);
277 
278 	/* set mode only for this engine */
279 	mode &= engine->engine_mask;
280 
281 	engine_state |= mode;
282 
283 	ret |= lp5523_write(client, LP5523_REG_OP_MODE, engine_state);
284 fail:
285 	return ret;
286 }
287 
288 static int lp5523_load_mux(struct lp5523_engine *engine, u16 mux)
289 {
290 	struct lp5523_chip *chip = engine_to_lp5523(engine);
291 	struct i2c_client *client = chip->client;
292 	int ret = 0;
293 
294 	ret |= lp5523_set_engine_mode(engine, LP5523_CMD_LOAD);
295 
296 	ret |= lp5523_write(client, LP5523_REG_PROG_PAGE_SEL, engine->mux_page);
297 	ret |= lp5523_write(client, LP5523_REG_PROG_MEM,
298 			    (u8)(mux >> 8));
299 	ret |= lp5523_write(client, LP5523_REG_PROG_MEM + 1, (u8)(mux));
300 	engine->led_mux = mux;
301 
302 	return ret;
303 }
304 
305 static int lp5523_load_program(struct lp5523_engine *engine, u8 *pattern)
306 {
307 	struct lp5523_chip *chip = engine_to_lp5523(engine);
308 	struct i2c_client *client = chip->client;
309 
310 	int ret = 0;
311 
312 	ret |= lp5523_set_engine_mode(engine, LP5523_CMD_LOAD);
313 
314 	ret |= lp5523_write(client, LP5523_REG_PROG_PAGE_SEL,
315 			    engine->prog_page);
316 	ret |= i2c_smbus_write_i2c_block_data(client, LP5523_REG_PROG_MEM,
317 					      LP5523_PROGRAM_LENGTH, pattern);
318 
319 	return ret;
320 }
321 
322 static int lp5523_run_program(struct lp5523_engine *engine)
323 {
324 	struct lp5523_chip *chip = engine_to_lp5523(engine);
325 	struct i2c_client *client = chip->client;
326 	int ret;
327 
328 	ret = lp5523_write(client, LP5523_REG_ENABLE,
329 					LP5523_CMD_RUN | LP5523_ENABLE);
330 	if (ret)
331 		goto fail;
332 
333 	ret = lp5523_set_engine_mode(engine, LP5523_CMD_RUN);
334 fail:
335 	return ret;
336 }
337 
338 static int lp5523_mux_parse(const char *buf, u16 *mux, size_t len)
339 {
340 	int i;
341 	u16 tmp_mux = 0;
342 	len = len < LP5523_LEDS ? len : LP5523_LEDS;
343 	for (i = 0; i < len; i++) {
344 		switch (buf[i]) {
345 		case '1':
346 			tmp_mux |= (1 << i);
347 			break;
348 		case '0':
349 			break;
350 		case '\n':
351 			i = len;
352 			break;
353 		default:
354 			return -1;
355 		}
356 	}
357 	*mux = tmp_mux;
358 
359 	return 0;
360 }
361 
362 static void lp5523_mux_to_array(u16 led_mux, char *array)
363 {
364 	int i, pos = 0;
365 	for (i = 0; i < LP5523_LEDS; i++)
366 		pos += sprintf(array + pos, "%x", LED_ACTIVE(led_mux, i));
367 
368 	array[pos] = '\0';
369 }
370 
371 /*--------------------------------------------------------------*/
372 /*			Sysfs interface				*/
373 /*--------------------------------------------------------------*/
374 
375 static ssize_t show_engine_leds(struct device *dev,
376 			    struct device_attribute *attr,
377 			    char *buf, int nr)
378 {
379 	struct i2c_client *client = to_i2c_client(dev);
380 	struct lp5523_chip *chip = i2c_get_clientdata(client);
381 	char mux[LP5523_LEDS + 1];
382 
383 	lp5523_mux_to_array(chip->engines[nr - 1].led_mux, mux);
384 
385 	return sprintf(buf, "%s\n", mux);
386 }
387 
388 #define show_leds(nr)							\
389 static ssize_t show_engine##nr##_leds(struct device *dev,		\
390 			    struct device_attribute *attr,		\
391 			    char *buf)					\
392 {									\
393 	return show_engine_leds(dev, attr, buf, nr);			\
394 }
395 show_leds(1)
396 show_leds(2)
397 show_leds(3)
398 
399 static ssize_t store_engine_leds(struct device *dev,
400 			     struct device_attribute *attr,
401 			     const char *buf, size_t len, int nr)
402 {
403 	struct i2c_client *client = to_i2c_client(dev);
404 	struct lp5523_chip *chip = i2c_get_clientdata(client);
405 	u16 mux = 0;
406 
407 	if (lp5523_mux_parse(buf, &mux, len))
408 		return -EINVAL;
409 
410 	if (lp5523_load_mux(&chip->engines[nr - 1], mux))
411 		return -EINVAL;
412 
413 	return len;
414 }
415 
416 #define store_leds(nr)						\
417 static ssize_t store_engine##nr##_leds(struct device *dev,	\
418 			     struct device_attribute *attr,	\
419 			     const char *buf, size_t len)	\
420 {								\
421 	return store_engine_leds(dev, attr, buf, len, nr);	\
422 }
423 store_leds(1)
424 store_leds(2)
425 store_leds(3)
426 
427 static ssize_t lp5523_selftest(struct device *dev,
428 			       struct device_attribute *attr,
429 			       char *buf)
430 {
431 	struct i2c_client *client = to_i2c_client(dev);
432 	struct lp5523_chip *chip = i2c_get_clientdata(client);
433 	int i, ret, pos = 0;
434 	int led = 0;
435 	u8 status, adc, vdd;
436 
437 	mutex_lock(&chip->lock);
438 
439 	ret = lp5523_read(chip->client, LP5523_REG_STATUS, &status);
440 	if (ret < 0)
441 		goto fail;
442 
443 	/* Check that ext clock is really in use if requested */
444 	if ((chip->pdata) && (chip->pdata->clock_mode == LP5523_CLOCK_EXT))
445 		if  ((status & LP5523_EXT_CLK_USED) == 0)
446 			goto fail;
447 
448 	/* Measure VDD (i.e. VBAT) first (channel 16 corresponds to VDD) */
449 	lp5523_write(chip->client, LP5523_REG_LED_TEST_CTRL,
450 				    LP5523_EN_LEDTEST | 16);
451 	usleep_range(3000, 6000); /* ADC conversion time is typically 2.7 ms */
452 	ret = lp5523_read(chip->client, LP5523_REG_STATUS, &status);
453 	if (!(status & LP5523_LEDTEST_DONE))
454 		usleep_range(3000, 6000); /* Was not ready. Wait little bit */
455 
456 	ret |= lp5523_read(chip->client, LP5523_REG_LED_TEST_ADC, &vdd);
457 	vdd--;	/* There may be some fluctuation in measurement */
458 
459 	for (i = 0; i < LP5523_LEDS; i++) {
460 		/* Skip non-existing channels */
461 		if (chip->pdata->led_config[i].led_current == 0)
462 			continue;
463 
464 		/* Set default current */
465 		lp5523_write(chip->client,
466 			LP5523_REG_LED_CURRENT_BASE + i,
467 			chip->pdata->led_config[i].led_current);
468 
469 		lp5523_write(chip->client, LP5523_REG_LED_PWM_BASE + i, 0xff);
470 		/* let current stabilize 2 - 4ms before measurements start */
471 		usleep_range(2000, 4000);
472 		lp5523_write(chip->client,
473 			     LP5523_REG_LED_TEST_CTRL,
474 			     LP5523_EN_LEDTEST | i);
475 		/* ADC conversion time is 2.7 ms typically */
476 		usleep_range(3000, 6000);
477 		ret = lp5523_read(chip->client, LP5523_REG_STATUS, &status);
478 		if (!(status & LP5523_LEDTEST_DONE))
479 			usleep_range(3000, 6000);/* Was not ready. Wait. */
480 		ret |= lp5523_read(chip->client, LP5523_REG_LED_TEST_ADC, &adc);
481 
482 		if (adc >= vdd || adc < LP5523_ADC_SHORTCIRC_LIM)
483 			pos += sprintf(buf + pos, "LED %d FAIL\n", i);
484 
485 		lp5523_write(chip->client, LP5523_REG_LED_PWM_BASE + i, 0x00);
486 
487 		/* Restore current */
488 		lp5523_write(chip->client,
489 			LP5523_REG_LED_CURRENT_BASE + i,
490 			chip->leds[led].led_current);
491 		led++;
492 	}
493 	if (pos == 0)
494 		pos = sprintf(buf, "OK\n");
495 	goto release_lock;
496 fail:
497 	pos = sprintf(buf, "FAIL\n");
498 
499 release_lock:
500 	mutex_unlock(&chip->lock);
501 
502 	return pos;
503 }
504 
505 static void lp5523_set_brightness(struct led_classdev *cdev,
506 			     enum led_brightness brightness)
507 {
508 	struct lp5523_led *led = cdev_to_led(cdev);
509 
510 	led->brightness = (u8)brightness;
511 
512 	schedule_work(&led->brightness_work);
513 }
514 
515 static void lp5523_led_brightness_work(struct work_struct *work)
516 {
517 	struct lp5523_led *led = container_of(work,
518 					      struct lp5523_led,
519 					      brightness_work);
520 	struct lp5523_chip *chip = led_to_lp5523(led);
521 	struct i2c_client *client = chip->client;
522 
523 	mutex_lock(&chip->lock);
524 
525 	lp5523_write(client, LP5523_REG_LED_PWM_BASE + led->chan_nr,
526 		     led->brightness);
527 
528 	mutex_unlock(&chip->lock);
529 }
530 
531 static int lp5523_do_store_load(struct lp5523_engine *engine,
532 				const char *buf, size_t len)
533 {
534 	struct lp5523_chip *chip = engine_to_lp5523(engine);
535 	struct i2c_client *client = chip->client;
536 	int  ret, nrchars, offset = 0, i = 0;
537 	char c[3];
538 	unsigned cmd;
539 	u8 pattern[LP5523_PROGRAM_LENGTH] = {0};
540 
541 	while ((offset < len - 1) && (i < LP5523_PROGRAM_LENGTH)) {
542 		/* separate sscanfs because length is working only for %s */
543 		ret = sscanf(buf + offset, "%2s%n ", c, &nrchars);
544 		ret = sscanf(c, "%2x", &cmd);
545 		if (ret != 1)
546 			goto fail;
547 		pattern[i] = (u8)cmd;
548 
549 		offset += nrchars;
550 		i++;
551 	}
552 
553 	/* Each instruction is 16bit long. Check that length is even */
554 	if (i % 2)
555 		goto fail;
556 
557 	mutex_lock(&chip->lock);
558 
559 	ret = lp5523_load_program(engine, pattern);
560 	mutex_unlock(&chip->lock);
561 
562 	if (ret) {
563 		dev_err(&client->dev, "failed loading pattern\n");
564 		return ret;
565 	}
566 
567 	return len;
568 fail:
569 	dev_err(&client->dev, "wrong pattern format\n");
570 	return -EINVAL;
571 }
572 
573 static ssize_t store_engine_load(struct device *dev,
574 				     struct device_attribute *attr,
575 				     const char *buf, size_t len, int nr)
576 {
577 	struct i2c_client *client = to_i2c_client(dev);
578 	struct lp5523_chip *chip = i2c_get_clientdata(client);
579 	return lp5523_do_store_load(&chip->engines[nr - 1], buf, len);
580 }
581 
582 #define store_load(nr)							\
583 static ssize_t store_engine##nr##_load(struct device *dev,		\
584 				     struct device_attribute *attr,	\
585 				     const char *buf, size_t len)	\
586 {									\
587 	return store_engine_load(dev, attr, buf, len, nr);		\
588 }
589 store_load(1)
590 store_load(2)
591 store_load(3)
592 
593 static ssize_t show_engine_mode(struct device *dev,
594 				struct device_attribute *attr,
595 				char *buf, int nr)
596 {
597 	struct i2c_client *client = to_i2c_client(dev);
598 	struct lp5523_chip *chip = i2c_get_clientdata(client);
599 	switch (chip->engines[nr - 1].mode) {
600 	case LP5523_CMD_RUN:
601 		return sprintf(buf, "run\n");
602 	case LP5523_CMD_LOAD:
603 		return sprintf(buf, "load\n");
604 	case LP5523_CMD_DISABLED:
605 		return sprintf(buf, "disabled\n");
606 	default:
607 		return sprintf(buf, "disabled\n");
608 	}
609 }
610 
611 #define show_mode(nr)							\
612 static ssize_t show_engine##nr##_mode(struct device *dev,		\
613 				    struct device_attribute *attr,	\
614 				    char *buf)				\
615 {									\
616 	return show_engine_mode(dev, attr, buf, nr);			\
617 }
618 show_mode(1)
619 show_mode(2)
620 show_mode(3)
621 
622 static ssize_t store_engine_mode(struct device *dev,
623 				 struct device_attribute *attr,
624 				 const char *buf, size_t len, int nr)
625 {
626 	struct i2c_client *client = to_i2c_client(dev);
627 	struct lp5523_chip *chip = i2c_get_clientdata(client);
628 	struct lp5523_engine *engine = &chip->engines[nr - 1];
629 	mutex_lock(&chip->lock);
630 
631 	if (!strncmp(buf, "run", 3))
632 		lp5523_set_mode(engine, LP5523_CMD_RUN);
633 	else if (!strncmp(buf, "load", 4))
634 		lp5523_set_mode(engine, LP5523_CMD_LOAD);
635 	else if (!strncmp(buf, "disabled", 8))
636 		lp5523_set_mode(engine, LP5523_CMD_DISABLED);
637 
638 	mutex_unlock(&chip->lock);
639 	return len;
640 }
641 
642 #define store_mode(nr)							\
643 static ssize_t store_engine##nr##_mode(struct device *dev,		\
644 				     struct device_attribute *attr,	\
645 				     const char *buf, size_t len)	\
646 {									\
647 	return store_engine_mode(dev, attr, buf, len, nr);		\
648 }
649 store_mode(1)
650 store_mode(2)
651 store_mode(3)
652 
653 static ssize_t show_max_current(struct device *dev,
654 			    struct device_attribute *attr,
655 			    char *buf)
656 {
657 	struct led_classdev *led_cdev = dev_get_drvdata(dev);
658 	struct lp5523_led *led = cdev_to_led(led_cdev);
659 
660 	return sprintf(buf, "%d\n", led->max_current);
661 }
662 
663 static ssize_t show_current(struct device *dev,
664 			    struct device_attribute *attr,
665 			    char *buf)
666 {
667 	struct led_classdev *led_cdev = dev_get_drvdata(dev);
668 	struct lp5523_led *led = cdev_to_led(led_cdev);
669 
670 	return sprintf(buf, "%d\n", led->led_current);
671 }
672 
673 static ssize_t store_current(struct device *dev,
674 			     struct device_attribute *attr,
675 			     const char *buf, size_t len)
676 {
677 	struct led_classdev *led_cdev = dev_get_drvdata(dev);
678 	struct lp5523_led *led = cdev_to_led(led_cdev);
679 	struct lp5523_chip *chip = led_to_lp5523(led);
680 	ssize_t ret;
681 	unsigned long curr;
682 
683 	if (strict_strtoul(buf, 0, &curr))
684 		return -EINVAL;
685 
686 	if (curr > led->max_current)
687 		return -EINVAL;
688 
689 	mutex_lock(&chip->lock);
690 	ret = lp5523_write(chip->client,
691 			LP5523_REG_LED_CURRENT_BASE + led->chan_nr,
692 			(u8)curr);
693 	mutex_unlock(&chip->lock);
694 
695 	if (ret < 0)
696 		return ret;
697 
698 	led->led_current = (u8)curr;
699 
700 	return len;
701 }
702 
703 /* led class device attributes */
704 static DEVICE_ATTR(led_current, S_IRUGO | S_IWUGO, show_current, store_current);
705 static DEVICE_ATTR(max_current, S_IRUGO , show_max_current, NULL);
706 
707 static struct attribute *lp5523_led_attributes[] = {
708 	&dev_attr_led_current.attr,
709 	&dev_attr_max_current.attr,
710 	NULL,
711 };
712 
713 static struct attribute_group lp5523_led_attribute_group = {
714 	.attrs = lp5523_led_attributes
715 };
716 
717 /* device attributes */
718 static DEVICE_ATTR(engine1_mode, S_IRUGO | S_IWUGO,
719 		   show_engine1_mode, store_engine1_mode);
720 static DEVICE_ATTR(engine2_mode, S_IRUGO | S_IWUGO,
721 		   show_engine2_mode, store_engine2_mode);
722 static DEVICE_ATTR(engine3_mode, S_IRUGO | S_IWUGO,
723 		   show_engine3_mode, store_engine3_mode);
724 static DEVICE_ATTR(engine1_leds, S_IRUGO | S_IWUGO,
725 		   show_engine1_leds, store_engine1_leds);
726 static DEVICE_ATTR(engine2_leds, S_IRUGO | S_IWUGO,
727 		   show_engine2_leds, store_engine2_leds);
728 static DEVICE_ATTR(engine3_leds, S_IRUGO | S_IWUGO,
729 		   show_engine3_leds, store_engine3_leds);
730 static DEVICE_ATTR(engine1_load, S_IWUGO, NULL, store_engine1_load);
731 static DEVICE_ATTR(engine2_load, S_IWUGO, NULL, store_engine2_load);
732 static DEVICE_ATTR(engine3_load, S_IWUGO, NULL, store_engine3_load);
733 static DEVICE_ATTR(selftest, S_IRUGO, lp5523_selftest, NULL);
734 
735 static struct attribute *lp5523_attributes[] = {
736 	&dev_attr_engine1_mode.attr,
737 	&dev_attr_engine2_mode.attr,
738 	&dev_attr_engine3_mode.attr,
739 	&dev_attr_selftest.attr,
740 	NULL
741 };
742 
743 static struct attribute *lp5523_engine1_attributes[] = {
744 	&dev_attr_engine1_load.attr,
745 	&dev_attr_engine1_leds.attr,
746 	NULL
747 };
748 
749 static struct attribute *lp5523_engine2_attributes[] = {
750 	&dev_attr_engine2_load.attr,
751 	&dev_attr_engine2_leds.attr,
752 	NULL
753 };
754 
755 static struct attribute *lp5523_engine3_attributes[] = {
756 	&dev_attr_engine3_load.attr,
757 	&dev_attr_engine3_leds.attr,
758 	NULL
759 };
760 
761 static const struct attribute_group lp5523_group = {
762 	.attrs = lp5523_attributes,
763 };
764 
765 static const struct attribute_group lp5523_engine_group[] = {
766 	{.attrs = lp5523_engine1_attributes },
767 	{.attrs = lp5523_engine2_attributes },
768 	{.attrs = lp5523_engine3_attributes },
769 };
770 
771 static int lp5523_register_sysfs(struct i2c_client *client)
772 {
773 	struct device *dev = &client->dev;
774 	int ret;
775 
776 	ret = sysfs_create_group(&dev->kobj, &lp5523_group);
777 	if (ret < 0)
778 		return ret;
779 
780 	return 0;
781 }
782 
783 static void lp5523_unregister_sysfs(struct i2c_client *client)
784 {
785 	struct lp5523_chip *chip = i2c_get_clientdata(client);
786 	struct device *dev = &client->dev;
787 	int i;
788 
789 	sysfs_remove_group(&dev->kobj, &lp5523_group);
790 
791 	for (i = 0; i < ARRAY_SIZE(chip->engines); i++)
792 		if (chip->engines[i].mode == LP5523_CMD_LOAD)
793 			sysfs_remove_group(&dev->kobj, &lp5523_engine_group[i]);
794 
795 	for (i = 0; i < chip->num_leds; i++)
796 		sysfs_remove_group(&chip->leds[i].cdev.dev->kobj,
797 				&lp5523_led_attribute_group);
798 }
799 
800 /*--------------------------------------------------------------*/
801 /*			Set chip operating mode			*/
802 /*--------------------------------------------------------------*/
803 static int lp5523_set_mode(struct lp5523_engine *engine, u8 mode)
804 {
805 	/*  engine to chip */
806 	struct lp5523_chip *chip = engine_to_lp5523(engine);
807 	struct i2c_client *client = chip->client;
808 	struct device *dev = &client->dev;
809 	int ret = 0;
810 
811 	/* if in that mode already do nothing, except for run */
812 	if (mode == engine->mode && mode != LP5523_CMD_RUN)
813 		return 0;
814 
815 	if (mode == LP5523_CMD_RUN) {
816 		ret = lp5523_run_program(engine);
817 	} else if (mode == LP5523_CMD_LOAD) {
818 		lp5523_set_engine_mode(engine, LP5523_CMD_DISABLED);
819 		lp5523_set_engine_mode(engine, LP5523_CMD_LOAD);
820 
821 		ret = sysfs_create_group(&dev->kobj, engine->attributes);
822 		if (ret)
823 			return ret;
824 	} else if (mode == LP5523_CMD_DISABLED) {
825 		lp5523_set_engine_mode(engine, LP5523_CMD_DISABLED);
826 	}
827 
828 	/* remove load attribute from sysfs if not in load mode */
829 	if (engine->mode == LP5523_CMD_LOAD && mode != LP5523_CMD_LOAD)
830 		sysfs_remove_group(&dev->kobj, engine->attributes);
831 
832 	engine->mode = mode;
833 
834 	return ret;
835 }
836 
837 /*--------------------------------------------------------------*/
838 /*			Probe, Attach, Remove			*/
839 /*--------------------------------------------------------------*/
840 static int __init lp5523_init_engine(struct lp5523_engine *engine, int id)
841 {
842 	if (id < 1 || id > LP5523_ENGINES)
843 		return -1;
844 	engine->id = id;
845 	engine->engine_mask = LP5523_ENG_MASK_BASE >> SHIFT_MASK(id);
846 	engine->prog_page = id - 1;
847 	engine->mux_page = id + 2;
848 	engine->attributes = &lp5523_engine_group[id - 1];
849 
850 	return 0;
851 }
852 
853 static int __init lp5523_init_led(struct lp5523_led *led, struct device *dev,
854 			   int chan, struct lp5523_platform_data *pdata)
855 {
856 	char name[32];
857 	int res;
858 
859 	if (chan >= LP5523_LEDS)
860 		return -EINVAL;
861 
862 	if (pdata->led_config[chan].led_current) {
863 		led->led_current = pdata->led_config[chan].led_current;
864 		led->max_current = pdata->led_config[chan].max_current;
865 		led->chan_nr = pdata->led_config[chan].chan_nr;
866 
867 		if (led->chan_nr >= LP5523_LEDS) {
868 			dev_err(dev, "Use channel numbers between 0 and %d\n",
869 				LP5523_LEDS - 1);
870 			return -EINVAL;
871 		}
872 
873 		snprintf(name, 32, "lp5523:channel%d", chan);
874 
875 		led->cdev.name = name;
876 		led->cdev.brightness_set = lp5523_set_brightness;
877 		res = led_classdev_register(dev, &led->cdev);
878 		if (res < 0) {
879 			dev_err(dev, "couldn't register led on channel %d\n",
880 				chan);
881 			return res;
882 		}
883 		res = sysfs_create_group(&led->cdev.dev->kobj,
884 				&lp5523_led_attribute_group);
885 		if (res < 0) {
886 			dev_err(dev, "couldn't register current attribute\n");
887 			led_classdev_unregister(&led->cdev);
888 			return res;
889 		}
890 	} else {
891 		led->led_current = 0;
892 	}
893 	return 0;
894 }
895 
896 static struct i2c_driver lp5523_driver;
897 
898 static int lp5523_probe(struct i2c_client *client,
899 			const struct i2c_device_id *id)
900 {
901 	struct lp5523_chip		*chip;
902 	struct lp5523_platform_data	*pdata;
903 	int ret, i, led;
904 
905 	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
906 	if (!chip)
907 		return -ENOMEM;
908 
909 	i2c_set_clientdata(client, chip);
910 	chip->client = client;
911 
912 	pdata = client->dev.platform_data;
913 
914 	if (!pdata) {
915 		dev_err(&client->dev, "no platform data\n");
916 		ret = -EINVAL;
917 		goto fail1;
918 	}
919 
920 	mutex_init(&chip->lock);
921 
922 	chip->pdata   = pdata;
923 
924 	if (pdata->setup_resources) {
925 		ret = pdata->setup_resources();
926 		if (ret < 0)
927 			goto fail1;
928 	}
929 
930 	if (pdata->enable) {
931 		pdata->enable(0);
932 		usleep_range(1000, 2000); /* Keep enable down at least 1ms */
933 		pdata->enable(1);
934 		usleep_range(1000, 2000); /* 500us abs min. */
935 	}
936 
937 	lp5523_write(client, LP5523_REG_RESET, 0xff);
938 	usleep_range(10000, 20000); /*
939 				     * Exact value is not available. 10 - 20ms
940 				     * appears to be enough for reset.
941 				     */
942 	ret = lp5523_detect(client);
943 	if (ret)
944 		goto fail2;
945 
946 	dev_info(&client->dev, "LP5523 Programmable led chip found\n");
947 
948 	/* Initialize engines */
949 	for (i = 0; i < ARRAY_SIZE(chip->engines); i++) {
950 		ret = lp5523_init_engine(&chip->engines[i], i + 1);
951 		if (ret) {
952 			dev_err(&client->dev, "error initializing engine\n");
953 			goto fail2;
954 		}
955 	}
956 	ret = lp5523_configure(client);
957 	if (ret < 0) {
958 		dev_err(&client->dev, "error configuring chip\n");
959 		goto fail2;
960 	}
961 
962 	/* Initialize leds */
963 	chip->num_channels = pdata->num_channels;
964 	chip->num_leds = 0;
965 	led = 0;
966 	for (i = 0; i < pdata->num_channels; i++) {
967 		/* Do not initialize channels that are not connected */
968 		if (pdata->led_config[i].led_current == 0)
969 			continue;
970 
971 		ret = lp5523_init_led(&chip->leds[led], &client->dev, i, pdata);
972 		if (ret) {
973 			dev_err(&client->dev, "error initializing leds\n");
974 			goto fail3;
975 		}
976 		chip->num_leds++;
977 
978 		chip->leds[led].id = led;
979 		/* Set LED current */
980 		lp5523_write(client,
981 			  LP5523_REG_LED_CURRENT_BASE + chip->leds[led].chan_nr,
982 			  chip->leds[led].led_current);
983 
984 		INIT_WORK(&(chip->leds[led].brightness_work),
985 			lp5523_led_brightness_work);
986 
987 		led++;
988 	}
989 
990 	ret = lp5523_register_sysfs(client);
991 	if (ret) {
992 		dev_err(&client->dev, "registering sysfs failed\n");
993 		goto fail3;
994 	}
995 	return ret;
996 fail3:
997 	for (i = 0; i < chip->num_leds; i++) {
998 		led_classdev_unregister(&chip->leds[i].cdev);
999 		cancel_work_sync(&chip->leds[i].brightness_work);
1000 	}
1001 fail2:
1002 	if (pdata->enable)
1003 		pdata->enable(0);
1004 	if (pdata->release_resources)
1005 		pdata->release_resources();
1006 fail1:
1007 	kfree(chip);
1008 	return ret;
1009 }
1010 
1011 static int lp5523_remove(struct i2c_client *client)
1012 {
1013 	struct lp5523_chip *chip = i2c_get_clientdata(client);
1014 	int i;
1015 
1016 	lp5523_unregister_sysfs(client);
1017 
1018 	for (i = 0; i < chip->num_leds; i++) {
1019 		led_classdev_unregister(&chip->leds[i].cdev);
1020 		cancel_work_sync(&chip->leds[i].brightness_work);
1021 	}
1022 
1023 	if (chip->pdata->enable)
1024 		chip->pdata->enable(0);
1025 	if (chip->pdata->release_resources)
1026 		chip->pdata->release_resources();
1027 	kfree(chip);
1028 	return 0;
1029 }
1030 
1031 static const struct i2c_device_id lp5523_id[] = {
1032 	{ "lp5523", 0 },
1033 	{ }
1034 };
1035 
1036 MODULE_DEVICE_TABLE(i2c, lp5523_id);
1037 
1038 static struct i2c_driver lp5523_driver = {
1039 	.driver = {
1040 		.name	= "lp5523",
1041 	},
1042 	.probe		= lp5523_probe,
1043 	.remove		= lp5523_remove,
1044 	.id_table	= lp5523_id,
1045 };
1046 
1047 static int __init lp5523_init(void)
1048 {
1049 	int ret;
1050 
1051 	ret = i2c_add_driver(&lp5523_driver);
1052 
1053 	if (ret < 0)
1054 		printk(KERN_ALERT "Adding lp5523 driver failed\n");
1055 
1056 	return ret;
1057 }
1058 
1059 static void __exit lp5523_exit(void)
1060 {
1061 	i2c_del_driver(&lp5523_driver);
1062 }
1063 
1064 module_init(lp5523_init);
1065 module_exit(lp5523_exit);
1066 
1067 MODULE_AUTHOR("Mathias Nyman <mathias.nyman@nokia.com>");
1068 MODULE_DESCRIPTION("LP5523 LED engine");
1069 MODULE_LICENSE("GPL");
1070