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OMAPDSS: VENC: fix NULL pointer dereference in DSS2 VENC sysfs debug attr on OMAP4
[zen-stable.git] / drivers / leds / leds-lp5521.c
blobd62a7982a5e66ad25812e87c86773985c3ffc802
1 /*
2 * LP5521 LED chip driver.
3 *
4 * Copyright (C) 2010 Nokia Corporation
5 *
6 * Contact: Samu Onkalo <samu.p.onkalo@nokia.com>
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * version 2 as published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20 * 02110-1301 USA
21 */
22
23 #include <linux/module.h>
24 #include <linux/init.h>
25 #include <linux/i2c.h>
26 #include <linux/mutex.h>
27 #include <linux/gpio.h>
28 #include <linux/interrupt.h>
29 #include <linux/delay.h>
30 #include <linux/ctype.h>
31 #include <linux/spinlock.h>
32 #include <linux/wait.h>
33 #include <linux/leds.h>
34 #include <linux/leds-lp5521.h>
35 #include <linux/workqueue.h>
36 #include <linux/slab.h>
37
38 #define LP5521_PROGRAM_LENGTH 32 /* in bytes */
39
40 #define LP5521_MAX_LEDS 3 /* Maximum number of LEDs */
41 #define LP5521_MAX_ENGINES 3 /* Maximum number of engines */
42
43 #define LP5521_ENG_MASK_BASE 0x30 /* 00110000 */
44 #define LP5521_ENG_STATUS_MASK 0x07 /* 00000111 */
45
46 #define LP5521_CMD_LOAD 0x15 /* 00010101 */
47 #define LP5521_CMD_RUN 0x2a /* 00101010 */
48 #define LP5521_CMD_DIRECT 0x3f /* 00111111 */
49 #define LP5521_CMD_DISABLED 0x00 /* 00000000 */
50
51 /* Registers */
52 #define LP5521_REG_ENABLE 0x00
53 #define LP5521_REG_OP_MODE 0x01
54 #define LP5521_REG_R_PWM 0x02
55 #define LP5521_REG_G_PWM 0x03
56 #define LP5521_REG_B_PWM 0x04
57 #define LP5521_REG_R_CURRENT 0x05
58 #define LP5521_REG_G_CURRENT 0x06
59 #define LP5521_REG_B_CURRENT 0x07
60 #define LP5521_REG_CONFIG 0x08
61 #define LP5521_REG_R_CHANNEL_PC 0x09
62 #define LP5521_REG_G_CHANNEL_PC 0x0A
63 #define LP5521_REG_B_CHANNEL_PC 0x0B
64 #define LP5521_REG_STATUS 0x0C
65 #define LP5521_REG_RESET 0x0D
66 #define LP5521_REG_GPO 0x0E
67 #define LP5521_REG_R_PROG_MEM 0x10
68 #define LP5521_REG_G_PROG_MEM 0x30
69 #define LP5521_REG_B_PROG_MEM 0x50
70
71 #define LP5521_PROG_MEM_BASE LP5521_REG_R_PROG_MEM
72 #define LP5521_PROG_MEM_SIZE 0x20
73
74 /* Base register to set LED current */
75 #define LP5521_REG_LED_CURRENT_BASE LP5521_REG_R_CURRENT
76
77 /* Base register to set the brightness */
78 #define LP5521_REG_LED_PWM_BASE LP5521_REG_R_PWM
79
80 /* Bits in ENABLE register */
81 #define LP5521_MASTER_ENABLE 0x40 /* Chip master enable */
82 #define LP5521_LOGARITHMIC_PWM 0x80 /* Logarithmic PWM adjustment */
83 #define LP5521_EXEC_RUN 0x2A
84
85 /* Bits in CONFIG register */
86 #define LP5521_PWM_HF 0x40 /* PWM: 0 = 256Hz, 1 = 558Hz */
87 #define LP5521_PWRSAVE_EN 0x20 /* 1 = Power save mode */
88 #define LP5521_CP_MODE_OFF 0 /* Charge pump (CP) off */
89 #define LP5521_CP_MODE_BYPASS 8 /* CP forced to bypass mode */
90 #define LP5521_CP_MODE_1X5 0x10 /* CP forced to 1.5x mode */
91 #define LP5521_CP_MODE_AUTO 0x18 /* Automatic mode selection */
92 #define LP5521_R_TO_BATT 4 /* R out: 0 = CP, 1 = Vbat */
93 #define LP5521_CLK_SRC_EXT 0 /* Ext-clk source (CLK_32K) */
94 #define LP5521_CLK_INT 1 /* Internal clock */
95 #define LP5521_CLK_AUTO 2 /* Automatic clock selection */
96
97 /* Status */
98 #define LP5521_EXT_CLK_USED 0x08
99
100 /* default R channel current register value */
101 #define LP5521_REG_R_CURR_DEFAULT 0xAF
102
103 struct lp5521_engine {
104 int id;
105 u8 mode;
106 u8 prog_page;
107 u8 engine_mask;
108 };
109
110 struct lp5521_led {
111 int id;
112 u8 chan_nr;
113 u8 led_current;
114 u8 max_current;
115 struct led_classdev cdev;
116 struct work_struct brightness_work;
117 u8 brightness;
118 };
119
120 struct lp5521_chip {
121 struct lp5521_platform_data *pdata;
122 struct mutex lock; /* Serialize control */
123 struct i2c_client *client;
124 struct lp5521_engine engines[LP5521_MAX_ENGINES];
125 struct lp5521_led leds[LP5521_MAX_LEDS];
126 u8 num_channels;
127 u8 num_leds;
128 };
129
130 static inline struct lp5521_led *cdev_to_led(struct led_classdev *cdev)
131 {
132 return container_of(cdev, struct lp5521_led, cdev);
133 }
134
135 static inline struct lp5521_chip *engine_to_lp5521(struct lp5521_engine *engine)
136 {
137 return container_of(engine, struct lp5521_chip,
138 engines[engine->id - 1]);
139 }
140
141 static inline struct lp5521_chip *led_to_lp5521(struct lp5521_led *led)
142 {
143 return container_of(led, struct lp5521_chip,
144 leds[led->id]);
145 }
146
147 static void lp5521_led_brightness_work(struct work_struct *work);
148
149 static inline int lp5521_write(struct i2c_client *client, u8 reg, u8 value)
150 {
151 return i2c_smbus_write_byte_data(client, reg, value);
152 }
153
154 static int lp5521_read(struct i2c_client *client, u8 reg, u8 *buf)
155 {
156 s32 ret;
157
158 ret = i2c_smbus_read_byte_data(client, reg);
159 if (ret < 0)
160 return -EIO;
161
162 *buf = ret;
163 return 0;
164 }
165
166 static int lp5521_set_engine_mode(struct lp5521_engine *engine, u8 mode)
167 {
168 struct lp5521_chip *chip = engine_to_lp5521(engine);
169 struct i2c_client *client = chip->client;
170 int ret;
171 u8 engine_state;
172
173 /* Only transition between RUN and DIRECT mode are handled here */
174 if (mode == LP5521_CMD_LOAD)
175 return 0;
176
177 if (mode == LP5521_CMD_DISABLED)
178 mode = LP5521_CMD_DIRECT;
179
180 ret = lp5521_read(client, LP5521_REG_OP_MODE, &engine_state);
181 if (ret < 0)
182 return ret;
183
184 /* set mode only for this engine */
185 engine_state &= ~(engine->engine_mask);
186 mode &= engine->engine_mask;
187 engine_state |= mode;
188 return lp5521_write(client, LP5521_REG_OP_MODE, engine_state);
189 }
190
191 static int lp5521_load_program(struct lp5521_engine *eng, const u8 *pattern)
192 {
193 struct lp5521_chip *chip = engine_to_lp5521(eng);
194 struct i2c_client *client = chip->client;
195 int ret;
196 int addr;
197 u8 mode;
198
199 /* move current engine to direct mode and remember the state */
200 ret = lp5521_set_engine_mode(eng, LP5521_CMD_DIRECT);
201 /* Mode change requires min 500 us delay. 1 - 2 ms with margin */
202 usleep_range(1000, 2000);
203 ret |= lp5521_read(client, LP5521_REG_OP_MODE, &mode);
204
205 /* For loading, all the engines to load mode */
206 lp5521_write(client, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT);
207 /* Mode change requires min 500 us delay. 1 - 2 ms with margin */
208 usleep_range(1000, 2000);
209 lp5521_write(client, LP5521_REG_OP_MODE, LP5521_CMD_LOAD);
210 /* Mode change requires min 500 us delay. 1 - 2 ms with margin */
211 usleep_range(1000, 2000);
212
213 addr = LP5521_PROG_MEM_BASE + eng->prog_page * LP5521_PROG_MEM_SIZE;
214 i2c_smbus_write_i2c_block_data(client,
215 addr,
216 LP5521_PROG_MEM_SIZE,
217 pattern);
218
219 ret |= lp5521_write(client, LP5521_REG_OP_MODE, mode);
220 return ret;
221 }
222
223 static int lp5521_set_led_current(struct lp5521_chip *chip, int led, u8 curr)
224 {
225 return lp5521_write(chip->client,
226 LP5521_REG_LED_CURRENT_BASE + chip->leds[led].chan_nr,
227 curr);
228 }
229
230 static void lp5521_init_engine(struct lp5521_chip *chip)
231 {
232 int i;
233 for (i = 0; i < ARRAY_SIZE(chip->engines); i++) {
234 chip->engines[i].id = i + 1;
235 chip->engines[i].engine_mask = LP5521_ENG_MASK_BASE >> (i * 2);
236 chip->engines[i].prog_page = i;
237 }
238 }
239
240 static int lp5521_configure(struct i2c_client *client)
241 {
242 struct lp5521_chip *chip = i2c_get_clientdata(client);
243 int ret;
244
245 lp5521_init_engine(chip);
246
247 /* Set all PWMs to direct control mode */
248 ret = lp5521_write(client, LP5521_REG_OP_MODE, 0x3F);
249
250 /* Enable auto-powersave, set charge pump to auto, red to battery */
251 ret |= lp5521_write(client, LP5521_REG_CONFIG,
252 LP5521_PWRSAVE_EN | LP5521_CP_MODE_AUTO | LP5521_R_TO_BATT);
253
254 /* Initialize all channels PWM to zero -> leds off */
255 ret |= lp5521_write(client, LP5521_REG_R_PWM, 0);
256 ret |= lp5521_write(client, LP5521_REG_G_PWM, 0);
257 ret |= lp5521_write(client, LP5521_REG_B_PWM, 0);
258
259 /* Set engines are set to run state when OP_MODE enables engines */
260 ret |= lp5521_write(client, LP5521_REG_ENABLE,
261 LP5521_MASTER_ENABLE | LP5521_LOGARITHMIC_PWM |
262 LP5521_EXEC_RUN);
263 /* enable takes 500us. 1 - 2 ms leaves some margin */
264 usleep_range(1000, 2000);
265
266 return ret;
267 }
268
269 static int lp5521_run_selftest(struct lp5521_chip *chip, char *buf)
270 {
271 int ret;
272 u8 status;
273
274 ret = lp5521_read(chip->client, LP5521_REG_STATUS, &status);
275 if (ret < 0)
276 return ret;
277
278 /* Check that ext clock is really in use if requested */
279 if (chip->pdata && chip->pdata->clock_mode == LP5521_CLOCK_EXT)
280 if ((status & LP5521_EXT_CLK_USED) == 0)
281 return -EIO;
282 return 0;
283 }
284
285 static void lp5521_set_brightness(struct led_classdev *cdev,
286 enum led_brightness brightness)
287 {
288 struct lp5521_led *led = cdev_to_led(cdev);
289 led->brightness = (u8)brightness;
290 schedule_work(&led->brightness_work);
291 }
292
293 static void lp5521_led_brightness_work(struct work_struct *work)
294 {
295 struct lp5521_led *led = container_of(work,
296 struct lp5521_led,
297 brightness_work);
298 struct lp5521_chip *chip = led_to_lp5521(led);
299 struct i2c_client *client = chip->client;
300
301 mutex_lock(&chip->lock);
302 lp5521_write(client, LP5521_REG_LED_PWM_BASE + led->chan_nr,
303 led->brightness);
304 mutex_unlock(&chip->lock);
305 }
306
307 /* Detect the chip by setting its ENABLE register and reading it back. */
308 static int lp5521_detect(struct i2c_client *client)
309 {
310 int ret;
311 u8 buf;
312
313 ret = lp5521_write(client, LP5521_REG_ENABLE,
314 LP5521_MASTER_ENABLE | LP5521_LOGARITHMIC_PWM);
315 if (ret)
316 return ret;
317 /* enable takes 500us. 1 - 2 ms leaves some margin */
318 usleep_range(1000, 2000);
319 ret = lp5521_read(client, LP5521_REG_ENABLE, &buf);
320 if (ret)
321 return ret;
322 if (buf != (LP5521_MASTER_ENABLE | LP5521_LOGARITHMIC_PWM))
323 return -ENODEV;
324
325 return 0;
326 }
327
328 /* Set engine mode and create appropriate sysfs attributes, if required. */
329 static int lp5521_set_mode(struct lp5521_engine *engine, u8 mode)
330 {
331 int ret = 0;
332
333 /* if in that mode already do nothing, except for run */
334 if (mode == engine->mode && mode != LP5521_CMD_RUN)
335 return 0;
336
337 if (mode == LP5521_CMD_RUN) {
338 ret = lp5521_set_engine_mode(engine, LP5521_CMD_RUN);
339 } else if (mode == LP5521_CMD_LOAD) {
340 lp5521_set_engine_mode(engine, LP5521_CMD_DISABLED);
341 lp5521_set_engine_mode(engine, LP5521_CMD_LOAD);
342 } else if (mode == LP5521_CMD_DISABLED) {
343 lp5521_set_engine_mode(engine, LP5521_CMD_DISABLED);
344 }
345
346 engine->mode = mode;
347
348 return ret;
349 }
350
351 static int lp5521_do_store_load(struct lp5521_engine *engine,
352 const char *buf, size_t len)
353 {
354 struct lp5521_chip *chip = engine_to_lp5521(engine);
355 struct i2c_client *client = chip->client;
356 int ret, nrchars, offset = 0, i = 0;
357 char c[3];
358 unsigned cmd;
359 u8 pattern[LP5521_PROGRAM_LENGTH] = {0};
360
361 while ((offset < len - 1) && (i < LP5521_PROGRAM_LENGTH)) {
362 /* separate sscanfs because length is working only for %s */
363 ret = sscanf(buf + offset, "%2s%n ", c, &nrchars);
364 if (ret != 2)
365 goto fail;
366 ret = sscanf(c, "%2x", &cmd);
367 if (ret != 1)
368 goto fail;
369 pattern[i] = (u8)cmd;
370
371 offset += nrchars;
372 i++;
373 }
374
375 /* Each instruction is 16bit long. Check that length is even */
376 if (i % 2)
377 goto fail;
378
379 mutex_lock(&chip->lock);
380 if (engine->mode == LP5521_CMD_LOAD)
381 ret = lp5521_load_program(engine, pattern);
382 else
383 ret = -EINVAL;
384 mutex_unlock(&chip->lock);
385
386 if (ret) {
387 dev_err(&client->dev, "failed loading pattern\n");
388 return ret;
389 }
390
391 return len;
392 fail:
393 dev_err(&client->dev, "wrong pattern format\n");
394 return -EINVAL;
395 }
396
397 static ssize_t store_engine_load(struct device *dev,
398 struct device_attribute *attr,
399 const char *buf, size_t len, int nr)
400 {
401 struct i2c_client *client = to_i2c_client(dev);
402 struct lp5521_chip *chip = i2c_get_clientdata(client);
403 return lp5521_do_store_load(&chip->engines[nr - 1], buf, len);
404 }
405
406 #define store_load(nr) \
407 static ssize_t store_engine##nr##_load(struct device *dev, \
408 struct device_attribute *attr, \
409 const char *buf, size_t len) \
410 { \
411 return store_engine_load(dev, attr, buf, len, nr); \
412 }
413 store_load(1)
414 store_load(2)
415 store_load(3)
416
417 static ssize_t show_engine_mode(struct device *dev,
418 struct device_attribute *attr,
419 char *buf, int nr)
420 {
421 struct i2c_client *client = to_i2c_client(dev);
422 struct lp5521_chip *chip = i2c_get_clientdata(client);
423 switch (chip->engines[nr - 1].mode) {
424 case LP5521_CMD_RUN:
425 return sprintf(buf, "run\n");
426 case LP5521_CMD_LOAD:
427 return sprintf(buf, "load\n");
428 case LP5521_CMD_DISABLED:
429 return sprintf(buf, "disabled\n");
430 default:
431 return sprintf(buf, "disabled\n");
432 }
433 }
434
435 #define show_mode(nr) \
436 static ssize_t show_engine##nr##_mode(struct device *dev, \
437 struct device_attribute *attr, \
438 char *buf) \
439 { \
440 return show_engine_mode(dev, attr, buf, nr); \
441 }
442 show_mode(1)
443 show_mode(2)
444 show_mode(3)
445
446 static ssize_t store_engine_mode(struct device *dev,
447 struct device_attribute *attr,
448 const char *buf, size_t len, int nr)
449 {
450 struct i2c_client *client = to_i2c_client(dev);
451 struct lp5521_chip *chip = i2c_get_clientdata(client);
452 struct lp5521_engine *engine = &chip->engines[nr - 1];
453 mutex_lock(&chip->lock);
454
455 if (!strncmp(buf, "run", 3))
456 lp5521_set_mode(engine, LP5521_CMD_RUN);
457 else if (!strncmp(buf, "load", 4))
458 lp5521_set_mode(engine, LP5521_CMD_LOAD);
459 else if (!strncmp(buf, "disabled", 8))
460 lp5521_set_mode(engine, LP5521_CMD_DISABLED);
461
462 mutex_unlock(&chip->lock);
463 return len;
464 }
465
466 #define store_mode(nr) \
467 static ssize_t store_engine##nr##_mode(struct device *dev, \
468 struct device_attribute *attr, \
469 const char *buf, size_t len) \
470 { \
471 return store_engine_mode(dev, attr, buf, len, nr); \
472 }
473 store_mode(1)
474 store_mode(2)
475 store_mode(3)
476
477 static ssize_t show_max_current(struct device *dev,
478 struct device_attribute *attr,
479 char *buf)
480 {
481 struct led_classdev *led_cdev = dev_get_drvdata(dev);
482 struct lp5521_led *led = cdev_to_led(led_cdev);
483
484 return sprintf(buf, "%d\n", led->max_current);
485 }
486
487 static ssize_t show_current(struct device *dev,
488 struct device_attribute *attr,
489 char *buf)
490 {
491 struct led_classdev *led_cdev = dev_get_drvdata(dev);
492 struct lp5521_led *led = cdev_to_led(led_cdev);
493
494 return sprintf(buf, "%d\n", led->led_current);
495 }
496
497 static ssize_t store_current(struct device *dev,
498 struct device_attribute *attr,
499 const char *buf, size_t len)
500 {
501 struct led_classdev *led_cdev = dev_get_drvdata(dev);
502 struct lp5521_led *led = cdev_to_led(led_cdev);
503 struct lp5521_chip *chip = led_to_lp5521(led);
504 ssize_t ret;
505 unsigned long curr;
506
507 if (strict_strtoul(buf, 0, &curr))
508 return -EINVAL;
509
510 if (curr > led->max_current)
511 return -EINVAL;
512
513 mutex_lock(&chip->lock);
514 ret = lp5521_set_led_current(chip, led->id, curr);
515 mutex_unlock(&chip->lock);
516
517 if (ret < 0)
518 return ret;
519
520 led->led_current = (u8)curr;
521
522 return len;
523 }
524
525 static ssize_t lp5521_selftest(struct device *dev,
526 struct device_attribute *attr,
527 char *buf)
528 {
529 struct i2c_client *client = to_i2c_client(dev);
530 struct lp5521_chip *chip = i2c_get_clientdata(client);
531 int ret;
532
533 mutex_lock(&chip->lock);
534 ret = lp5521_run_selftest(chip, buf);
535 mutex_unlock(&chip->lock);
536 return sprintf(buf, "%s\n", ret ? "FAIL" : "OK");
537 }
538
539 /* led class device attributes */
540 static DEVICE_ATTR(led_current, S_IRUGO | S_IWUSR, show_current, store_current);
541 static DEVICE_ATTR(max_current, S_IRUGO , show_max_current, NULL);
542
543 static struct attribute *lp5521_led_attributes[] = {
544 &dev_attr_led_current.attr,
545 &dev_attr_max_current.attr,
546 NULL,
547 };
548
549 static struct attribute_group lp5521_led_attribute_group = {
550 .attrs = lp5521_led_attributes
551 };
552
553 /* device attributes */
554 static DEVICE_ATTR(engine1_mode, S_IRUGO | S_IWUSR,
555 show_engine1_mode, store_engine1_mode);
556 static DEVICE_ATTR(engine2_mode, S_IRUGO | S_IWUSR,
557 show_engine2_mode, store_engine2_mode);
558 static DEVICE_ATTR(engine3_mode, S_IRUGO | S_IWUSR,
559 show_engine3_mode, store_engine3_mode);
560 static DEVICE_ATTR(engine1_load, S_IWUSR, NULL, store_engine1_load);
561 static DEVICE_ATTR(engine2_load, S_IWUSR, NULL, store_engine2_load);
562 static DEVICE_ATTR(engine3_load, S_IWUSR, NULL, store_engine3_load);
563 static DEVICE_ATTR(selftest, S_IRUGO, lp5521_selftest, NULL);
564
565 static struct attribute *lp5521_attributes[] = {
566 &dev_attr_engine1_mode.attr,
567 &dev_attr_engine2_mode.attr,
568 &dev_attr_engine3_mode.attr,
569 &dev_attr_selftest.attr,
570 &dev_attr_engine1_load.attr,
571 &dev_attr_engine2_load.attr,
572 &dev_attr_engine3_load.attr,
573 NULL
574 };
575
576 static const struct attribute_group lp5521_group = {
577 .attrs = lp5521_attributes,
578 };
579
580 static int lp5521_register_sysfs(struct i2c_client *client)
581 {
582 struct device *dev = &client->dev;
583 return sysfs_create_group(&dev->kobj, &lp5521_group);
584 }
585
586 static void lp5521_unregister_sysfs(struct i2c_client *client)
587 {
588 struct lp5521_chip *chip = i2c_get_clientdata(client);
589 struct device *dev = &client->dev;
590 int i;
591
592 sysfs_remove_group(&dev->kobj, &lp5521_group);
593
594 for (i = 0; i < chip->num_leds; i++)
595 sysfs_remove_group(&chip->leds[i].cdev.dev->kobj,
596 &lp5521_led_attribute_group);
597 }
598
599 static int __devinit lp5521_init_led(struct lp5521_led *led,
600 struct i2c_client *client,
601 int chan, struct lp5521_platform_data *pdata)
602 {
603 struct device *dev = &client->dev;
604 char name[32];
605 int res;
606
607 if (chan >= LP5521_MAX_LEDS)
608 return -EINVAL;
609
610 if (pdata->led_config[chan].led_current == 0)
611 return 0;
612
613 led->led_current = pdata->led_config[chan].led_current;
614 led->max_current = pdata->led_config[chan].max_current;
615 led->chan_nr = pdata->led_config[chan].chan_nr;
616
617 if (led->chan_nr >= LP5521_MAX_LEDS) {
618 dev_err(dev, "Use channel numbers between 0 and %d\n",
619 LP5521_MAX_LEDS - 1);
620 return -EINVAL;
621 }
622
623 snprintf(name, sizeof(name), "%s:channel%d",
624 pdata->label ?: client->name, chan);
625 led->cdev.brightness_set = lp5521_set_brightness;
626 led->cdev.name = name;
627 res = led_classdev_register(dev, &led->cdev);
628 if (res < 0) {
629 dev_err(dev, "couldn't register led on channel %d\n", chan);
630 return res;
631 }
632
633 res = sysfs_create_group(&led->cdev.dev->kobj,
634 &lp5521_led_attribute_group);
635 if (res < 0) {
636 dev_err(dev, "couldn't register current attribute\n");
637 led_classdev_unregister(&led->cdev);
638 return res;
639 }
640 return 0;
641 }
642
643 static int __devinit lp5521_probe(struct i2c_client *client,
644 const struct i2c_device_id *id)
645 {
646 struct lp5521_chip *chip;
647 struct lp5521_platform_data *pdata;
648 int ret, i, led;
649 u8 buf;
650
651 chip = kzalloc(sizeof(*chip), GFP_KERNEL);
652 if (!chip)
653 return -ENOMEM;
654
655 i2c_set_clientdata(client, chip);
656 chip->client = client;
657
658 pdata = client->dev.platform_data;
659
660 if (!pdata) {
661 dev_err(&client->dev, "no platform data\n");
662 ret = -EINVAL;
663 goto fail1;
664 }
665
666 mutex_init(&chip->lock);
667
668 chip->pdata = pdata;
669
670 if (pdata->setup_resources) {
671 ret = pdata->setup_resources();
672 if (ret < 0)
673 goto fail1;
674 }
675
676 if (pdata->enable) {
677 pdata->enable(0);
678 usleep_range(1000, 2000); /* Keep enable down at least 1ms */
679 pdata->enable(1);
680 usleep_range(1000, 2000); /* 500us abs min. */
681 }
682
683 lp5521_write(client, LP5521_REG_RESET, 0xff);
684 usleep_range(10000, 20000); /*
685 * Exact value is not available. 10 - 20ms
686 * appears to be enough for reset.
687 */
688
689 /*
690 * Make sure that the chip is reset by reading back the r channel
691 * current reg. This is dummy read is required on some platforms -
692 * otherwise further access to the R G B channels in the
693 * LP5521_REG_ENABLE register will not have any effect - strange!
694 */
695 lp5521_read(client, LP5521_REG_R_CURRENT, &buf);
696 if (buf != LP5521_REG_R_CURR_DEFAULT) {
697 dev_err(&client->dev, "error in reseting chip\n");
698 goto fail2;
699 }
700 usleep_range(10000, 20000);
701
702 ret = lp5521_detect(client);
703
704 if (ret) {
705 dev_err(&client->dev, "Chip not found\n");
706 goto fail2;
707 }
708
709 dev_info(&client->dev, "%s programmable led chip found\n", id->name);
710
711 ret = lp5521_configure(client);
712 if (ret < 0) {
713 dev_err(&client->dev, "error configuring chip\n");
714 goto fail2;
715 }
716
717 /* Initialize leds */
718 chip->num_channels = pdata->num_channels;
719 chip->num_leds = 0;
720 led = 0;
721 for (i = 0; i < pdata->num_channels; i++) {
722 /* Do not initialize channels that are not connected */
723 if (pdata->led_config[i].led_current == 0)
724 continue;
725
726 ret = lp5521_init_led(&chip->leds[led], client, i, pdata);
727 if (ret) {
728 dev_err(&client->dev, "error initializing leds\n");
729 goto fail3;
730 }
731 chip->num_leds++;
732
733 chip->leds[led].id = led;
734 /* Set initial LED current */
735 lp5521_set_led_current(chip, led,
736 chip->leds[led].led_current);
737
738 INIT_WORK(&(chip->leds[led].brightness_work),
739 lp5521_led_brightness_work);
740
741 led++;
742 }
743
744 ret = lp5521_register_sysfs(client);
745 if (ret) {
746 dev_err(&client->dev, "registering sysfs failed\n");
747 goto fail3;
748 }
749 return ret;
750 fail3:
751 for (i = 0; i < chip->num_leds; i++) {
752 led_classdev_unregister(&chip->leds[i].cdev);
753 cancel_work_sync(&chip->leds[i].brightness_work);
754 }
755 fail2:
756 if (pdata->enable)
757 pdata->enable(0);
758 if (pdata->release_resources)
759 pdata->release_resources();
760 fail1:
761 kfree(chip);
762 return ret;
763 }
764
765 static int __devexit lp5521_remove(struct i2c_client *client)
766 {
767 struct lp5521_chip *chip = i2c_get_clientdata(client);
768 int i;
769
770 lp5521_unregister_sysfs(client);
771
772 for (i = 0; i < chip->num_leds; i++) {
773 led_classdev_unregister(&chip->leds[i].cdev);
774 cancel_work_sync(&chip->leds[i].brightness_work);
775 }
776
777 if (chip->pdata->enable)
778 chip->pdata->enable(0);
779 if (chip->pdata->release_resources)
780 chip->pdata->release_resources();
781 kfree(chip);
782 return 0;
783 }
784
785 static const struct i2c_device_id lp5521_id[] = {
786 { "lp5521", 0 }, /* Three channel chip */
787 { }
788 };
789 MODULE_DEVICE_TABLE(i2c, lp5521_id);
790
791 static struct i2c_driver lp5521_driver = {
792 .driver = {
793 .name = "lp5521",
794 },
795 .probe = lp5521_probe,
796 .remove = __devexit_p(lp5521_remove),
797 .id_table = lp5521_id,
798 };
799
800 module_i2c_driver(lp5521_driver);
801
802 MODULE_AUTHOR("Mathias Nyman, Yuri Zaporozhets, Samu Onkalo");
803 MODULE_DESCRIPTION("LP5521 LED engine");
804 MODULE_LICENSE("GPL v2");