Root/drivers/leds/leds-lp5521.c

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#define LP5521_ENABLE_DEFAULT \
85    (LP5521_MASTER_ENABLE | LP5521_LOGARITHMIC_PWM)
86#define LP5521_ENABLE_RUN_PROGRAM \
87    (LP5521_ENABLE_DEFAULT | LP5521_EXEC_RUN)
88
89/* Status */
90#define LP5521_EXT_CLK_USED 0x08
91
92/* default R channel current register value */
93#define LP5521_REG_R_CURR_DEFAULT 0xAF
94
95/* Pattern Mode */
96#define PATTERN_OFF 0
97
98struct lp5521_engine {
99    int id;
100    u8 mode;
101    u8 prog_page;
102    u8 engine_mask;
103};
104
105struct lp5521_led {
106    int id;
107    u8 chan_nr;
108    u8 led_current;
109    u8 max_current;
110    struct led_classdev cdev;
111    struct work_struct brightness_work;
112    u8 brightness;
113};
114
115struct lp5521_chip {
116    struct lp5521_platform_data *pdata;
117    struct mutex lock; /* Serialize control */
118    struct i2c_client *client;
119    struct lp5521_engine engines[LP5521_MAX_ENGINES];
120    struct lp5521_led leds[LP5521_MAX_LEDS];
121    u8 num_channels;
122    u8 num_leds;
123};
124
125static inline struct lp5521_led *cdev_to_led(struct led_classdev *cdev)
126{
127    return container_of(cdev, struct lp5521_led, cdev);
128}
129
130static inline struct lp5521_chip *engine_to_lp5521(struct lp5521_engine *engine)
131{
132    return container_of(engine, struct lp5521_chip,
133                engines[engine->id - 1]);
134}
135
136static inline struct lp5521_chip *led_to_lp5521(struct lp5521_led *led)
137{
138    return container_of(led, struct lp5521_chip,
139                leds[led->id]);
140}
141
142static void lp5521_led_brightness_work(struct work_struct *work);
143
144static inline int lp5521_write(struct i2c_client *client, u8 reg, u8 value)
145{
146    return i2c_smbus_write_byte_data(client, reg, value);
147}
148
149static int lp5521_read(struct i2c_client *client, u8 reg, u8 *buf)
150{
151    s32 ret;
152
153    ret = i2c_smbus_read_byte_data(client, reg);
154    if (ret < 0)
155        return -EIO;
156
157    *buf = ret;
158    return 0;
159}
160
161static int lp5521_set_engine_mode(struct lp5521_engine *engine, u8 mode)
162{
163    struct lp5521_chip *chip = engine_to_lp5521(engine);
164    struct i2c_client *client = chip->client;
165    int ret;
166    u8 engine_state;
167
168    /* Only transition between RUN and DIRECT mode are handled here */
169    if (mode == LP5521_CMD_LOAD)
170        return 0;
171
172    if (mode == LP5521_CMD_DISABLED)
173        mode = LP5521_CMD_DIRECT;
174
175    ret = lp5521_read(client, LP5521_REG_OP_MODE, &engine_state);
176    if (ret < 0)
177        return ret;
178
179    /* set mode only for this engine */
180    engine_state &= ~(engine->engine_mask);
181    mode &= engine->engine_mask;
182    engine_state |= mode;
183    return lp5521_write(client, LP5521_REG_OP_MODE, engine_state);
184}
185
186static int lp5521_load_program(struct lp5521_engine *eng, const u8 *pattern)
187{
188    struct lp5521_chip *chip = engine_to_lp5521(eng);
189    struct i2c_client *client = chip->client;
190    int ret;
191    int addr;
192    u8 mode;
193
194    /* move current engine to direct mode and remember the state */
195    ret = lp5521_set_engine_mode(eng, LP5521_CMD_DIRECT);
196    if (ret)
197        return ret;
198
199    /* Mode change requires min 500 us delay. 1 - 2 ms with margin */
200    usleep_range(1000, 2000);
201    ret = lp5521_read(client, LP5521_REG_OP_MODE, &mode);
202    if (ret)
203        return ret;
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    return lp5521_write(client, LP5521_REG_OP_MODE, mode);
220}
221
222static int lp5521_set_led_current(struct lp5521_chip *chip, int led, u8 curr)
223{
224    return lp5521_write(chip->client,
225            LP5521_REG_LED_CURRENT_BASE + chip->leds[led].chan_nr,
226            curr);
227}
228
229static void lp5521_init_engine(struct lp5521_chip *chip)
230{
231    int i;
232    for (i = 0; i < ARRAY_SIZE(chip->engines); i++) {
233        chip->engines[i].id = i + 1;
234        chip->engines[i].engine_mask = LP5521_ENG_MASK_BASE >> (i * 2);
235        chip->engines[i].prog_page = i;
236    }
237}
238
239static int lp5521_configure(struct i2c_client *client)
240{
241    struct lp5521_chip *chip = i2c_get_clientdata(client);
242    int ret;
243    u8 cfg;
244
245    lp5521_init_engine(chip);
246
247    /* Set all PWMs to direct control mode */
248    ret = lp5521_write(client, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT);
249
250    cfg = chip->pdata->update_config ?
251        : (LP5521_PWRSAVE_EN | LP5521_CP_MODE_AUTO | LP5521_R_TO_BATT);
252    ret |= lp5521_write(client, LP5521_REG_CONFIG, cfg);
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_ENABLE_RUN_PROGRAM);
262    /* enable takes 500us. 1 - 2 ms leaves some margin */
263    usleep_range(1000, 2000);
264
265    return ret;
266}
267
268static int lp5521_run_selftest(struct lp5521_chip *chip, char *buf)
269{
270    int ret;
271    u8 status;
272
273    ret = lp5521_read(chip->client, LP5521_REG_STATUS, &status);
274    if (ret < 0)
275        return ret;
276
277    /* Check that ext clock is really in use if requested */
278    if (chip->pdata && chip->pdata->clock_mode == LP5521_CLOCK_EXT)
279        if ((status & LP5521_EXT_CLK_USED) == 0)
280            return -EIO;
281    return 0;
282}
283
284static void lp5521_set_brightness(struct led_classdev *cdev,
285                 enum led_brightness brightness)
286{
287    struct lp5521_led *led = cdev_to_led(cdev);
288    led->brightness = (u8)brightness;
289    schedule_work(&led->brightness_work);
290}
291
292static void lp5521_led_brightness_work(struct work_struct *work)
293{
294    struct lp5521_led *led = container_of(work,
295                          struct lp5521_led,
296                          brightness_work);
297    struct lp5521_chip *chip = led_to_lp5521(led);
298    struct i2c_client *client = chip->client;
299
300    mutex_lock(&chip->lock);
301    lp5521_write(client, LP5521_REG_LED_PWM_BASE + led->chan_nr,
302        led->brightness);
303    mutex_unlock(&chip->lock);
304}
305
306/* Detect the chip by setting its ENABLE register and reading it back. */
307static int lp5521_detect(struct i2c_client *client)
308{
309    int ret;
310    u8 buf;
311
312    ret = lp5521_write(client, LP5521_REG_ENABLE, LP5521_ENABLE_DEFAULT);
313    if (ret)
314        return ret;
315    /* enable takes 500us. 1 - 2 ms leaves some margin */
316    usleep_range(1000, 2000);
317    ret = lp5521_read(client, LP5521_REG_ENABLE, &buf);
318    if (ret)
319        return ret;
320    if (buf != LP5521_ENABLE_DEFAULT)
321        return -ENODEV;
322
323    return 0;
324}
325
326/* Set engine mode and create appropriate sysfs attributes, if required. */
327static int lp5521_set_mode(struct lp5521_engine *engine, u8 mode)
328{
329    int ret = 0;
330
331    /* if in that mode already do nothing, except for run */
332    if (mode == engine->mode && mode != LP5521_CMD_RUN)
333        return 0;
334
335    if (mode == LP5521_CMD_RUN) {
336        ret = lp5521_set_engine_mode(engine, LP5521_CMD_RUN);
337    } else if (mode == LP5521_CMD_LOAD) {
338        lp5521_set_engine_mode(engine, LP5521_CMD_DISABLED);
339        lp5521_set_engine_mode(engine, LP5521_CMD_LOAD);
340    } else if (mode == LP5521_CMD_DISABLED) {
341        lp5521_set_engine_mode(engine, LP5521_CMD_DISABLED);
342    }
343
344    engine->mode = mode;
345
346    return ret;
347}
348
349static int lp5521_do_store_load(struct lp5521_engine *engine,
350                const char *buf, size_t len)
351{
352    struct lp5521_chip *chip = engine_to_lp5521(engine);
353    struct i2c_client *client = chip->client;
354    int ret, nrchars, offset = 0, i = 0;
355    char c[3];
356    unsigned cmd;
357    u8 pattern[LP5521_PROGRAM_LENGTH] = {0};
358
359    while ((offset < len - 1) && (i < LP5521_PROGRAM_LENGTH)) {
360        /* separate sscanfs because length is working only for %s */
361        ret = sscanf(buf + offset, "%2s%n ", c, &nrchars);
362        if (ret != 2)
363            goto fail;
364        ret = sscanf(c, "%2x", &cmd);
365        if (ret != 1)
366            goto fail;
367        pattern[i] = (u8)cmd;
368
369        offset += nrchars;
370        i++;
371    }
372
373    /* Each instruction is 16bit long. Check that length is even */
374    if (i % 2)
375        goto fail;
376
377    mutex_lock(&chip->lock);
378    if (engine->mode == LP5521_CMD_LOAD)
379        ret = lp5521_load_program(engine, pattern);
380    else
381        ret = -EINVAL;
382    mutex_unlock(&chip->lock);
383
384    if (ret) {
385        dev_err(&client->dev, "failed loading pattern\n");
386        return ret;
387    }
388
389    return len;
390fail:
391    dev_err(&client->dev, "wrong pattern format\n");
392    return -EINVAL;
393}
394
395static ssize_t store_engine_load(struct device *dev,
396                     struct device_attribute *attr,
397                     const char *buf, size_t len, int nr)
398{
399    struct i2c_client *client = to_i2c_client(dev);
400    struct lp5521_chip *chip = i2c_get_clientdata(client);
401    return lp5521_do_store_load(&chip->engines[nr - 1], buf, len);
402}
403
404#define store_load(nr) \
405static ssize_t store_engine##nr##_load(struct device *dev, \
406                     struct device_attribute *attr, \
407                     const char *buf, size_t len) \
408{ \
409    return store_engine_load(dev, attr, buf, len, nr); \
410}
411store_load(1)
412store_load(2)
413store_load(3)
414
415static ssize_t show_engine_mode(struct device *dev,
416                struct device_attribute *attr,
417                char *buf, int nr)
418{
419    struct i2c_client *client = to_i2c_client(dev);
420    struct lp5521_chip *chip = i2c_get_clientdata(client);
421    switch (chip->engines[nr - 1].mode) {
422    case LP5521_CMD_RUN:
423        return sprintf(buf, "run\n");
424    case LP5521_CMD_LOAD:
425        return sprintf(buf, "load\n");
426    case LP5521_CMD_DISABLED:
427        return sprintf(buf, "disabled\n");
428    default:
429        return sprintf(buf, "disabled\n");
430    }
431}
432
433#define show_mode(nr) \
434static ssize_t show_engine##nr##_mode(struct device *dev, \
435                    struct device_attribute *attr, \
436                    char *buf) \
437{ \
438    return show_engine_mode(dev, attr, buf, nr); \
439}
440show_mode(1)
441show_mode(2)
442show_mode(3)
443
444static ssize_t store_engine_mode(struct device *dev,
445                 struct device_attribute *attr,
446                 const char *buf, size_t len, int nr)
447{
448    struct i2c_client *client = to_i2c_client(dev);
449    struct lp5521_chip *chip = i2c_get_clientdata(client);
450    struct lp5521_engine *engine = &chip->engines[nr - 1];
451    mutex_lock(&chip->lock);
452
453    if (!strncmp(buf, "run", 3))
454        lp5521_set_mode(engine, LP5521_CMD_RUN);
455    else if (!strncmp(buf, "load", 4))
456        lp5521_set_mode(engine, LP5521_CMD_LOAD);
457    else if (!strncmp(buf, "disabled", 8))
458        lp5521_set_mode(engine, LP5521_CMD_DISABLED);
459
460    mutex_unlock(&chip->lock);
461    return len;
462}
463
464#define store_mode(nr) \
465static ssize_t store_engine##nr##_mode(struct device *dev, \
466                     struct device_attribute *attr, \
467                     const char *buf, size_t len) \
468{ \
469    return store_engine_mode(dev, attr, buf, len, nr); \
470}
471store_mode(1)
472store_mode(2)
473store_mode(3)
474
475static ssize_t show_max_current(struct device *dev,
476                struct device_attribute *attr,
477                char *buf)
478{
479    struct led_classdev *led_cdev = dev_get_drvdata(dev);
480    struct lp5521_led *led = cdev_to_led(led_cdev);
481
482    return sprintf(buf, "%d\n", led->max_current);
483}
484
485static ssize_t show_current(struct device *dev,
486                struct device_attribute *attr,
487                char *buf)
488{
489    struct led_classdev *led_cdev = dev_get_drvdata(dev);
490    struct lp5521_led *led = cdev_to_led(led_cdev);
491
492    return sprintf(buf, "%d\n", led->led_current);
493}
494
495static ssize_t store_current(struct device *dev,
496                 struct device_attribute *attr,
497                 const char *buf, size_t len)
498{
499    struct led_classdev *led_cdev = dev_get_drvdata(dev);
500    struct lp5521_led *led = cdev_to_led(led_cdev);
501    struct lp5521_chip *chip = led_to_lp5521(led);
502    ssize_t ret;
503    unsigned long curr;
504
505    if (kstrtoul(buf, 0, &curr))
506        return -EINVAL;
507
508    if (curr > led->max_current)
509        return -EINVAL;
510
511    mutex_lock(&chip->lock);
512    ret = lp5521_set_led_current(chip, led->id, curr);
513    mutex_unlock(&chip->lock);
514
515    if (ret < 0)
516        return ret;
517
518    led->led_current = (u8)curr;
519
520    return len;
521}
522
523static ssize_t lp5521_selftest(struct device *dev,
524                   struct device_attribute *attr,
525                   char *buf)
526{
527    struct i2c_client *client = to_i2c_client(dev);
528    struct lp5521_chip *chip = i2c_get_clientdata(client);
529    int ret;
530
531    mutex_lock(&chip->lock);
532    ret = lp5521_run_selftest(chip, buf);
533    mutex_unlock(&chip->lock);
534    return sprintf(buf, "%s\n", ret ? "FAIL" : "OK");
535}
536
537static void lp5521_clear_program_memory(struct i2c_client *cl)
538{
539    int i;
540    u8 rgb_mem[] = {
541        LP5521_REG_R_PROG_MEM,
542        LP5521_REG_G_PROG_MEM,
543        LP5521_REG_B_PROG_MEM,
544    };
545
546    for (i = 0; i < ARRAY_SIZE(rgb_mem); i++) {
547        lp5521_write(cl, rgb_mem[i], 0);
548        lp5521_write(cl, rgb_mem[i] + 1, 0);
549    }
550}
551
552static void lp5521_write_program_memory(struct i2c_client *cl,
553                u8 base, u8 *rgb, int size)
554{
555    int i;
556
557    if (!rgb || size <= 0)
558        return;
559
560    for (i = 0; i < size; i++)
561        lp5521_write(cl, base + i, *(rgb + i));
562
563    lp5521_write(cl, base + i, 0);
564    lp5521_write(cl, base + i + 1, 0);
565}
566
567static inline struct lp5521_led_pattern *lp5521_get_pattern
568                    (struct lp5521_chip *chip, u8 offset)
569{
570    struct lp5521_led_pattern *ptn;
571    ptn = chip->pdata->patterns + (offset - 1);
572    return ptn;
573}
574
575static void lp5521_run_led_pattern(int mode, struct lp5521_chip *chip)
576{
577    struct lp5521_led_pattern *ptn;
578    struct i2c_client *cl = chip->client;
579    int num_patterns = chip->pdata->num_patterns;
580
581    if (mode > num_patterns || !(chip->pdata->patterns))
582        return;
583
584    if (mode == PATTERN_OFF) {
585        lp5521_write(cl, LP5521_REG_ENABLE, LP5521_ENABLE_DEFAULT);
586        usleep_range(1000, 2000);
587        lp5521_write(cl, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT);
588    } else {
589        ptn = lp5521_get_pattern(chip, mode);
590        if (!ptn)
591            return;
592
593        lp5521_write(cl, LP5521_REG_OP_MODE, LP5521_CMD_LOAD);
594        usleep_range(1000, 2000);
595
596        lp5521_clear_program_memory(cl);
597
598        lp5521_write_program_memory(cl, LP5521_REG_R_PROG_MEM,
599                    ptn->r, ptn->size_r);
600        lp5521_write_program_memory(cl, LP5521_REG_G_PROG_MEM,
601                    ptn->g, ptn->size_g);
602        lp5521_write_program_memory(cl, LP5521_REG_B_PROG_MEM,
603                    ptn->b, ptn->size_b);
604
605        lp5521_write(cl, LP5521_REG_OP_MODE, LP5521_CMD_RUN);
606        usleep_range(1000, 2000);
607        lp5521_write(cl, LP5521_REG_ENABLE, LP5521_ENABLE_RUN_PROGRAM);
608    }
609}
610
611static ssize_t store_led_pattern(struct device *dev,
612                struct device_attribute *attr,
613                const char *buf, size_t len)
614{
615    struct lp5521_chip *chip = i2c_get_clientdata(to_i2c_client(dev));
616    unsigned long val;
617    int ret;
618
619    ret = strict_strtoul(buf, 16, &val);
620    if (ret)
621        return ret;
622
623    lp5521_run_led_pattern(val, chip);
624
625    return len;
626}
627
628/* led class device attributes */
629static DEVICE_ATTR(led_current, S_IRUGO | S_IWUSR, show_current, store_current);
630static DEVICE_ATTR(max_current, S_IRUGO , show_max_current, NULL);
631
632static struct attribute *lp5521_led_attributes[] = {
633    &dev_attr_led_current.attr,
634    &dev_attr_max_current.attr,
635    NULL,
636};
637
638static struct attribute_group lp5521_led_attribute_group = {
639    .attrs = lp5521_led_attributes
640};
641
642/* device attributes */
643static DEVICE_ATTR(engine1_mode, S_IRUGO | S_IWUSR,
644           show_engine1_mode, store_engine1_mode);
645static DEVICE_ATTR(engine2_mode, S_IRUGO | S_IWUSR,
646           show_engine2_mode, store_engine2_mode);
647static DEVICE_ATTR(engine3_mode, S_IRUGO | S_IWUSR,
648           show_engine3_mode, store_engine3_mode);
649static DEVICE_ATTR(engine1_load, S_IWUSR, NULL, store_engine1_load);
650static DEVICE_ATTR(engine2_load, S_IWUSR, NULL, store_engine2_load);
651static DEVICE_ATTR(engine3_load, S_IWUSR, NULL, store_engine3_load);
652static DEVICE_ATTR(selftest, S_IRUGO, lp5521_selftest, NULL);
653static DEVICE_ATTR(led_pattern, S_IWUSR, NULL, store_led_pattern);
654
655static struct attribute *lp5521_attributes[] = {
656    &dev_attr_engine1_mode.attr,
657    &dev_attr_engine2_mode.attr,
658    &dev_attr_engine3_mode.attr,
659    &dev_attr_selftest.attr,
660    &dev_attr_engine1_load.attr,
661    &dev_attr_engine2_load.attr,
662    &dev_attr_engine3_load.attr,
663    &dev_attr_led_pattern.attr,
664    NULL
665};
666
667static const struct attribute_group lp5521_group = {
668    .attrs = lp5521_attributes,
669};
670
671static int lp5521_register_sysfs(struct i2c_client *client)
672{
673    struct device *dev = &client->dev;
674    return sysfs_create_group(&dev->kobj, &lp5521_group);
675}
676
677static void lp5521_unregister_sysfs(struct i2c_client *client)
678{
679    struct lp5521_chip *chip = i2c_get_clientdata(client);
680    struct device *dev = &client->dev;
681    int i;
682
683    sysfs_remove_group(&dev->kobj, &lp5521_group);
684
685    for (i = 0; i < chip->num_leds; i++)
686        sysfs_remove_group(&chip->leds[i].cdev.dev->kobj,
687                &lp5521_led_attribute_group);
688}
689
690static int __devinit lp5521_init_led(struct lp5521_led *led,
691                struct i2c_client *client,
692                int chan, struct lp5521_platform_data *pdata)
693{
694    struct device *dev = &client->dev;
695    char name[32];
696    int res;
697
698    if (chan >= LP5521_MAX_LEDS)
699        return -EINVAL;
700
701    if (pdata->led_config[chan].led_current == 0)
702        return 0;
703
704    led->led_current = pdata->led_config[chan].led_current;
705    led->max_current = pdata->led_config[chan].max_current;
706    led->chan_nr = pdata->led_config[chan].chan_nr;
707
708    if (led->chan_nr >= LP5521_MAX_LEDS) {
709        dev_err(dev, "Use channel numbers between 0 and %d\n",
710            LP5521_MAX_LEDS - 1);
711        return -EINVAL;
712    }
713
714    led->cdev.brightness_set = lp5521_set_brightness;
715    if (pdata->led_config[chan].name) {
716        led->cdev.name = pdata->led_config[chan].name;
717    } else {
718        snprintf(name, sizeof(name), "%s:channel%d",
719            pdata->label ?: client->name, chan);
720        led->cdev.name = name;
721    }
722
723    res = led_classdev_register(dev, &led->cdev);
724    if (res < 0) {
725        dev_err(dev, "couldn't register led on channel %d\n", chan);
726        return res;
727    }
728
729    res = sysfs_create_group(&led->cdev.dev->kobj,
730            &lp5521_led_attribute_group);
731    if (res < 0) {
732        dev_err(dev, "couldn't register current attribute\n");
733        led_classdev_unregister(&led->cdev);
734        return res;
735    }
736    return 0;
737}
738
739static int __devinit lp5521_probe(struct i2c_client *client,
740            const struct i2c_device_id *id)
741{
742    struct lp5521_chip *chip;
743    struct lp5521_platform_data *pdata;
744    int ret, i, led;
745    u8 buf;
746
747    chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
748    if (!chip)
749        return -ENOMEM;
750
751    i2c_set_clientdata(client, chip);
752    chip->client = client;
753
754    pdata = client->dev.platform_data;
755
756    if (!pdata) {
757        dev_err(&client->dev, "no platform data\n");
758        return -EINVAL;
759    }
760
761    mutex_init(&chip->lock);
762
763    chip->pdata = pdata;
764
765    if (pdata->setup_resources) {
766        ret = pdata->setup_resources();
767        if (ret < 0)
768            return ret;
769    }
770
771    if (pdata->enable) {
772        pdata->enable(0);
773        usleep_range(1000, 2000); /* Keep enable down at least 1ms */
774        pdata->enable(1);
775        usleep_range(1000, 2000); /* 500us abs min. */
776    }
777
778    lp5521_write(client, LP5521_REG_RESET, 0xff);
779    usleep_range(10000, 20000); /*
780                     * Exact value is not available. 10 - 20ms
781                     * appears to be enough for reset.
782                     */
783
784    /*
785     * Make sure that the chip is reset by reading back the r channel
786     * current reg. This is dummy read is required on some platforms -
787     * otherwise further access to the R G B channels in the
788     * LP5521_REG_ENABLE register will not have any effect - strange!
789     */
790    ret = lp5521_read(client, LP5521_REG_R_CURRENT, &buf);
791    if (ret || buf != LP5521_REG_R_CURR_DEFAULT) {
792        dev_err(&client->dev, "error in resetting chip\n");
793        goto fail2;
794    }
795    usleep_range(10000, 20000);
796
797    ret = lp5521_detect(client);
798
799    if (ret) {
800        dev_err(&client->dev, "Chip not found\n");
801        goto fail2;
802    }
803
804    dev_info(&client->dev, "%s programmable led chip found\n", id->name);
805
806    ret = lp5521_configure(client);
807    if (ret < 0) {
808        dev_err(&client->dev, "error configuring chip\n");
809        goto fail1;
810    }
811
812    /* Initialize leds */
813    chip->num_channels = pdata->num_channels;
814    chip->num_leds = 0;
815    led = 0;
816    for (i = 0; i < pdata->num_channels; i++) {
817        /* Do not initialize channels that are not connected */
818        if (pdata->led_config[i].led_current == 0)
819            continue;
820
821        ret = lp5521_init_led(&chip->leds[led], client, i, pdata);
822        if (ret) {
823            dev_err(&client->dev, "error initializing leds\n");
824            goto fail2;
825        }
826        chip->num_leds++;
827
828        chip->leds[led].id = led;
829        /* Set initial LED current */
830        lp5521_set_led_current(chip, led,
831                chip->leds[led].led_current);
832
833        INIT_WORK(&(chip->leds[led].brightness_work),
834            lp5521_led_brightness_work);
835
836        led++;
837    }
838
839    ret = lp5521_register_sysfs(client);
840    if (ret) {
841        dev_err(&client->dev, "registering sysfs failed\n");
842        goto fail2;
843    }
844    return ret;
845fail2:
846    for (i = 0; i < chip->num_leds; i++) {
847        led_classdev_unregister(&chip->leds[i].cdev);
848        cancel_work_sync(&chip->leds[i].brightness_work);
849    }
850fail1:
851    if (pdata->enable)
852        pdata->enable(0);
853    if (pdata->release_resources)
854        pdata->release_resources();
855    return ret;
856}
857
858static int __devexit lp5521_remove(struct i2c_client *client)
859{
860    struct lp5521_chip *chip = i2c_get_clientdata(client);
861    int i;
862
863    lp5521_run_led_pattern(PATTERN_OFF, chip);
864    lp5521_unregister_sysfs(client);
865
866    for (i = 0; i < chip->num_leds; i++) {
867        led_classdev_unregister(&chip->leds[i].cdev);
868        cancel_work_sync(&chip->leds[i].brightness_work);
869    }
870
871    if (chip->pdata->enable)
872        chip->pdata->enable(0);
873    if (chip->pdata->release_resources)
874        chip->pdata->release_resources();
875    return 0;
876}
877
878static const struct i2c_device_id lp5521_id[] = {
879    { "lp5521", 0 }, /* Three channel chip */
880    { }
881};
882MODULE_DEVICE_TABLE(i2c, lp5521_id);
883
884static struct i2c_driver lp5521_driver = {
885    .driver = {
886        .name = "lp5521",
887    },
888    .probe = lp5521_probe,
889    .remove = __devexit_p(lp5521_remove),
890    .id_table = lp5521_id,
891};
892
893module_i2c_driver(lp5521_driver);
894
895MODULE_AUTHOR("Mathias Nyman, Yuri Zaporozhets, Samu Onkalo");
896MODULE_DESCRIPTION("LP5521 LED engine");
897MODULE_LICENSE("GPL v2");
898

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