a036a19040fea90b70ba93a93eac99401f85567a
[linux-3.10.git] / drivers / leds / leds-lm3530.c
1 /*
2  * Copyright (C) 2011 ST-Ericsson SA.
3  * Copyright (C) 2009 Motorola, Inc.
4  *
5  * License Terms: GNU General Public License v2
6  *
7  * Simple driver for National Semiconductor LM3530 Backlight driver chip
8  *
9  * Author: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>
10  * based on leds-lm3530.c by Dan Murphy <D.Murphy@motorola.com>
11  */
12
13 #include <linux/i2c.h>
14 #include <linux/leds.h>
15 #include <linux/slab.h>
16 #include <linux/platform_device.h>
17 #include <linux/input.h>
18 #include <linux/led-lm3530.h>
19 #include <linux/types.h>
20 #include <linux/regulator/consumer.h>
21 #include <linux/module.h>
22
23 #define LM3530_LED_DEV "lcd-backlight"
24 #define LM3530_NAME "lm3530-led"
25
26 #define LM3530_GEN_CONFIG               0x10
27 #define LM3530_ALS_CONFIG               0x20
28 #define LM3530_BRT_RAMP_RATE            0x30
29 #define LM3530_ALS_IMP_SELECT           0x41
30 #define LM3530_BRT_CTRL_REG             0xA0
31 #define LM3530_ALS_ZB0_REG              0x60
32 #define LM3530_ALS_ZB1_REG              0x61
33 #define LM3530_ALS_ZB2_REG              0x62
34 #define LM3530_ALS_ZB3_REG              0x63
35 #define LM3530_ALS_Z0T_REG              0x70
36 #define LM3530_ALS_Z1T_REG              0x71
37 #define LM3530_ALS_Z2T_REG              0x72
38 #define LM3530_ALS_Z3T_REG              0x73
39 #define LM3530_ALS_Z4T_REG              0x74
40 #define LM3530_REG_MAX                  14
41
42 /* General Control Register */
43 #define LM3530_EN_I2C_SHIFT             (0)
44 #define LM3530_RAMP_LAW_SHIFT           (1)
45 #define LM3530_MAX_CURR_SHIFT           (2)
46 #define LM3530_EN_PWM_SHIFT             (5)
47 #define LM3530_PWM_POL_SHIFT            (6)
48 #define LM3530_EN_PWM_SIMPLE_SHIFT      (7)
49
50 #define LM3530_ENABLE_I2C               (1 << LM3530_EN_I2C_SHIFT)
51 #define LM3530_ENABLE_PWM               (1 << LM3530_EN_PWM_SHIFT)
52 #define LM3530_POL_LOW                  (1 << LM3530_PWM_POL_SHIFT)
53 #define LM3530_ENABLE_PWM_SIMPLE        (1 << LM3530_EN_PWM_SIMPLE_SHIFT)
54
55 /* ALS Config Register Options */
56 #define LM3530_ALS_AVG_TIME_SHIFT       (0)
57 #define LM3530_EN_ALS_SHIFT             (3)
58 #define LM3530_ALS_SEL_SHIFT            (5)
59
60 #define LM3530_ENABLE_ALS               (3 << LM3530_EN_ALS_SHIFT)
61
62 /* Brightness Ramp Rate Register */
63 #define LM3530_BRT_RAMP_FALL_SHIFT      (0)
64 #define LM3530_BRT_RAMP_RISE_SHIFT      (3)
65
66 /* ALS Resistor Select */
67 #define LM3530_ALS1_IMP_SHIFT           (0)
68 #define LM3530_ALS2_IMP_SHIFT           (4)
69
70 /* Zone Boundary Register defaults */
71 #define LM3530_ALS_ZB_MAX               (4)
72 #define LM3530_ALS_WINDOW_mV            (1000)
73 #define LM3530_ALS_OFFSET_mV            (4)
74
75 /* Zone Target Register defaults */
76 #define LM3530_DEF_ZT_0                 (0x7F)
77 #define LM3530_DEF_ZT_1                 (0x66)
78 #define LM3530_DEF_ZT_2                 (0x4C)
79 #define LM3530_DEF_ZT_3                 (0x33)
80 #define LM3530_DEF_ZT_4                 (0x19)
81
82 /* 7 bits are used for the brightness : LM3530_BRT_CTRL_REG */
83 #define MAX_BRIGHTNESS                  (127)
84
85 struct lm3530_mode_map {
86         const char *mode;
87         enum lm3530_mode mode_val;
88 };
89
90 static struct lm3530_mode_map mode_map[] = {
91         { "man", LM3530_BL_MODE_MANUAL },
92         { "als", LM3530_BL_MODE_ALS },
93         { "pwm", LM3530_BL_MODE_PWM },
94 };
95
96 /**
97  * struct lm3530_data
98  * @led_dev: led class device
99  * @client: i2c client
100  * @pdata: LM3530 platform data
101  * @mode: mode of operation - manual, ALS, PWM
102  * @regulator: regulator
103  * @brighness: previous brightness value
104  * @enable: regulator is enabled
105  */
106 struct lm3530_data {
107         struct led_classdev led_dev;
108         struct i2c_client *client;
109         struct lm3530_platform_data *pdata;
110         enum lm3530_mode mode;
111         struct regulator *regulator;
112         enum led_brightness brightness;
113         bool enable;
114 };
115
116 /*
117  * struct lm3530_als_data
118  * @config  : value of ALS configuration register
119  * @imp_sel : value of ALS resistor select register
120  * @zone    : values of ALS ZB(Zone Boundary) registers
121  */
122 struct lm3530_als_data {
123         u8 config;
124         u8 imp_sel;
125         u8 zones[LM3530_ALS_ZB_MAX];
126 };
127
128 static const u8 lm3530_reg[LM3530_REG_MAX] = {
129         LM3530_GEN_CONFIG,
130         LM3530_ALS_CONFIG,
131         LM3530_BRT_RAMP_RATE,
132         LM3530_ALS_IMP_SELECT,
133         LM3530_BRT_CTRL_REG,
134         LM3530_ALS_ZB0_REG,
135         LM3530_ALS_ZB1_REG,
136         LM3530_ALS_ZB2_REG,
137         LM3530_ALS_ZB3_REG,
138         LM3530_ALS_Z0T_REG,
139         LM3530_ALS_Z1T_REG,
140         LM3530_ALS_Z2T_REG,
141         LM3530_ALS_Z3T_REG,
142         LM3530_ALS_Z4T_REG,
143 };
144
145 static int lm3530_get_mode_from_str(const char *str)
146 {
147         int i;
148
149         for (i = 0; i < ARRAY_SIZE(mode_map); i++)
150                 if (sysfs_streq(str, mode_map[i].mode))
151                         return mode_map[i].mode_val;
152
153         return -EINVAL;
154 }
155
156 static void lm3530_als_configure(struct lm3530_platform_data *pdata,
157                                 struct lm3530_als_data *als)
158 {
159         int i;
160         u32 als_vmin, als_vmax, als_vstep;
161
162         if (pdata->als_vmax == 0) {
163                 pdata->als_vmin = 0;
164                 pdata->als_vmax = LM3530_ALS_WINDOW_mV;
165         }
166
167         als_vmin = pdata->als_vmin;
168         als_vmax = pdata->als_vmax;
169
170         if ((als_vmax - als_vmin) > LM3530_ALS_WINDOW_mV)
171                 pdata->als_vmax = als_vmax = als_vmin + LM3530_ALS_WINDOW_mV;
172
173         /* n zone boundary makes n+1 zones */
174         als_vstep = (als_vmax - als_vmin) / (LM3530_ALS_ZB_MAX + 1);
175
176         for (i = 0; i < LM3530_ALS_ZB_MAX; i++)
177                 als->zones[i] = (((als_vmin + LM3530_ALS_OFFSET_mV) +
178                         als_vstep + (i * als_vstep)) * LED_FULL) / 1000;
179
180         als->config =
181                 (pdata->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) |
182                 (LM3530_ENABLE_ALS) |
183                 (pdata->als_input_mode << LM3530_ALS_SEL_SHIFT);
184
185         als->imp_sel =
186                 (pdata->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) |
187                 (pdata->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);
188 }
189
190 static int lm3530_led_enable(struct lm3530_data *drvdata)
191 {
192         int ret;
193
194         if (drvdata->enable)
195                 return 0;
196
197         ret = regulator_enable(drvdata->regulator);
198         if (ret) {
199                 dev_err(drvdata->led_dev.dev, "Failed to enable vin:%d\n", ret);
200                 return ret;
201         }
202
203         drvdata->enable = true;
204         return 0;
205 }
206
207 static void lm3530_led_disable(struct lm3530_data *drvdata)
208 {
209         int ret;
210
211         if (!drvdata->enable)
212                 return;
213
214         ret = regulator_disable(drvdata->regulator);
215         if (ret) {
216                 dev_err(drvdata->led_dev.dev, "Failed to disable vin:%d\n",
217                         ret);
218                 return;
219         }
220
221         drvdata->enable = false;
222 }
223
224 static int lm3530_init_registers(struct lm3530_data *drvdata)
225 {
226         int ret = 0;
227         int i;
228         u8 gen_config;
229         u8 brt_ramp;
230         u8 brightness;
231         u8 reg_val[LM3530_REG_MAX];
232         struct lm3530_platform_data *pdata = drvdata->pdata;
233         struct i2c_client *client = drvdata->client;
234         struct lm3530_pwm_data *pwm = &pdata->pwm_data;
235         struct lm3530_als_data als;
236
237         memset(&als, 0, sizeof(struct lm3530_als_data));
238
239         gen_config = (pdata->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) |
240                         ((pdata->max_current & 7) << LM3530_MAX_CURR_SHIFT);
241
242         switch (drvdata->mode) {
243         case LM3530_BL_MODE_MANUAL:
244                 gen_config |= LM3530_ENABLE_I2C;
245                 break;
246         case LM3530_BL_MODE_ALS:
247                 gen_config |= LM3530_ENABLE_I2C;
248                 lm3530_als_configure(pdata, &als);
249                 break;
250         case LM3530_BL_MODE_PWM:
251                 gen_config |= LM3530_ENABLE_PWM | LM3530_ENABLE_PWM_SIMPLE |
252                               (pdata->pwm_pol_hi << LM3530_PWM_POL_SHIFT);
253                 break;
254         }
255
256         brt_ramp = (pdata->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) |
257                         (pdata->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);
258
259         if (drvdata->brightness)
260                 brightness = drvdata->brightness;
261         else
262                 brightness = drvdata->brightness = pdata->brt_val;
263
264         if (brightness > drvdata->led_dev.max_brightness)
265                 brightness = drvdata->led_dev.max_brightness;
266
267         reg_val[0] = gen_config;        /* LM3530_GEN_CONFIG */
268         reg_val[1] = als.config;        /* LM3530_ALS_CONFIG */
269         reg_val[2] = brt_ramp;          /* LM3530_BRT_RAMP_RATE */
270         reg_val[3] = als.imp_sel;       /* LM3530_ALS_IMP_SELECT */
271         reg_val[4] = brightness;        /* LM3530_BRT_CTRL_REG */
272         reg_val[5] = als.zones[0];      /* LM3530_ALS_ZB0_REG */
273         reg_val[6] = als.zones[1];      /* LM3530_ALS_ZB1_REG */
274         reg_val[7] = als.zones[2];      /* LM3530_ALS_ZB2_REG */
275         reg_val[8] = als.zones[3];      /* LM3530_ALS_ZB3_REG */
276         reg_val[9] = LM3530_DEF_ZT_0;   /* LM3530_ALS_Z0T_REG */
277         reg_val[10] = LM3530_DEF_ZT_1;  /* LM3530_ALS_Z1T_REG */
278         reg_val[11] = LM3530_DEF_ZT_2;  /* LM3530_ALS_Z2T_REG */
279         reg_val[12] = LM3530_DEF_ZT_3;  /* LM3530_ALS_Z3T_REG */
280         reg_val[13] = LM3530_DEF_ZT_4;  /* LM3530_ALS_Z4T_REG */
281
282         ret = lm3530_led_enable(drvdata);
283         if (ret)
284                 return ret;
285
286         for (i = 0; i < LM3530_REG_MAX; i++) {
287                 /* do not update brightness register when pwm mode */
288                 if (lm3530_reg[i] == LM3530_BRT_CTRL_REG &&
289                     drvdata->mode == LM3530_BL_MODE_PWM) {
290                         if (pwm->pwm_set_intensity)
291                                 pwm->pwm_set_intensity(reg_val[i],
292                                         drvdata->led_dev.max_brightness);
293                         continue;
294                 }
295
296                 ret = i2c_smbus_write_byte_data(client,
297                                 lm3530_reg[i], reg_val[i]);
298                 if (ret)
299                         break;
300         }
301
302         return ret;
303 }
304
305 static void lm3530_brightness_set(struct led_classdev *led_cdev,
306                                      enum led_brightness brt_val)
307 {
308         int err;
309         struct lm3530_data *drvdata =
310             container_of(led_cdev, struct lm3530_data, led_dev);
311         struct lm3530_platform_data *pdata = drvdata->pdata;
312         struct lm3530_pwm_data *pwm = &pdata->pwm_data;
313         u8 max_brightness = led_cdev->max_brightness;
314
315         switch (drvdata->mode) {
316         case LM3530_BL_MODE_MANUAL:
317
318                 if (!drvdata->enable) {
319                         err = lm3530_init_registers(drvdata);
320                         if (err) {
321                                 dev_err(&drvdata->client->dev,
322                                         "Register Init failed: %d\n", err);
323                                 break;
324                         }
325                 }
326
327                 /* set the brightness in brightness control register*/
328                 err = i2c_smbus_write_byte_data(drvdata->client,
329                                 LM3530_BRT_CTRL_REG, brt_val);
330                 if (err)
331                         dev_err(&drvdata->client->dev,
332                                 "Unable to set brightness: %d\n", err);
333                 else
334                         drvdata->brightness = brt_val;
335
336                 if (brt_val == 0)
337                         lm3530_led_disable(drvdata);
338                 break;
339         case LM3530_BL_MODE_ALS:
340                 break;
341         case LM3530_BL_MODE_PWM:
342                 if (pwm->pwm_set_intensity)
343                         pwm->pwm_set_intensity(brt_val, max_brightness);
344                 break;
345         default:
346                 break;
347         }
348 }
349
350 static ssize_t lm3530_mode_get(struct device *dev,
351                 struct device_attribute *attr, char *buf)
352 {
353         struct led_classdev *led_cdev = dev_get_drvdata(dev);
354         struct lm3530_data *drvdata;
355         int i, len = 0;
356
357         drvdata = container_of(led_cdev, struct lm3530_data, led_dev);
358         for (i = 0; i < ARRAY_SIZE(mode_map); i++)
359                 if (drvdata->mode == mode_map[i].mode_val)
360                         len += sprintf(buf + len, "[%s] ", mode_map[i].mode);
361                 else
362                         len += sprintf(buf + len, "%s ", mode_map[i].mode);
363
364         len += sprintf(buf + len, "\n");
365
366         return len;
367 }
368
369 static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute
370                                    *attr, const char *buf, size_t size)
371 {
372         struct led_classdev *led_cdev = dev_get_drvdata(dev);
373         struct lm3530_data *drvdata;
374         struct lm3530_pwm_data *pwm;
375         u8 max_brightness;
376         int mode, err;
377
378         drvdata = container_of(led_cdev, struct lm3530_data, led_dev);
379         pwm = &drvdata->pdata->pwm_data;
380         max_brightness = led_cdev->max_brightness;
381         mode = lm3530_get_mode_from_str(buf);
382         if (mode < 0) {
383                 dev_err(dev, "Invalid mode\n");
384                 return mode;
385         }
386
387         drvdata->mode = mode;
388
389         /* set pwm to low if unnecessary */
390         if (mode != LM3530_BL_MODE_PWM && pwm->pwm_set_intensity)
391                 pwm->pwm_set_intensity(0, max_brightness);
392
393         err = lm3530_init_registers(drvdata);
394         if (err) {
395                 dev_err(dev, "Setting %s Mode failed :%d\n", buf, err);
396                 return err;
397         }
398
399         return sizeof(drvdata->mode);
400 }
401 static DEVICE_ATTR(mode, 0644, lm3530_mode_get, lm3530_mode_set);
402
403 static int lm3530_probe(struct i2c_client *client,
404                            const struct i2c_device_id *id)
405 {
406         struct lm3530_platform_data *pdata = client->dev.platform_data;
407         struct lm3530_data *drvdata;
408         int err = 0;
409
410         if (pdata == NULL) {
411                 dev_err(&client->dev, "platform data required\n");
412                 return -ENODEV;
413         }
414
415         /* BL mode */
416         if (pdata->mode > LM3530_BL_MODE_PWM) {
417                 dev_err(&client->dev, "Illegal Mode request\n");
418                 return -EINVAL;
419         }
420
421         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
422                 dev_err(&client->dev, "I2C_FUNC_I2C not supported\n");
423                 return -EIO;
424         }
425
426         drvdata = devm_kzalloc(&client->dev, sizeof(struct lm3530_data),
427                                 GFP_KERNEL);
428         if (drvdata == NULL)
429                 return -ENOMEM;
430
431         drvdata->mode = pdata->mode;
432         drvdata->client = client;
433         drvdata->pdata = pdata;
434         drvdata->brightness = LED_OFF;
435         drvdata->enable = false;
436         drvdata->led_dev.name = LM3530_LED_DEV;
437         drvdata->led_dev.brightness_set = lm3530_brightness_set;
438         drvdata->led_dev.max_brightness = MAX_BRIGHTNESS;
439
440         i2c_set_clientdata(client, drvdata);
441
442         drvdata->regulator = devm_regulator_get(&client->dev, "vin");
443         if (IS_ERR(drvdata->regulator)) {
444                 dev_err(&client->dev, "regulator get failed\n");
445                 err = PTR_ERR(drvdata->regulator);
446                 drvdata->regulator = NULL;
447                 return err;
448         }
449
450         if (drvdata->pdata->brt_val) {
451                 err = lm3530_init_registers(drvdata);
452                 if (err < 0) {
453                         dev_err(&client->dev,
454                                 "Register Init failed: %d\n", err);
455                         return err;
456                 }
457         }
458         err = led_classdev_register(&client->dev, &drvdata->led_dev);
459         if (err < 0) {
460                 dev_err(&client->dev, "Register led class failed: %d\n", err);
461                 return err;
462         }
463
464         err = device_create_file(drvdata->led_dev.dev, &dev_attr_mode);
465         if (err < 0) {
466                 dev_err(&client->dev, "File device creation failed: %d\n", err);
467                 err = -ENODEV;
468                 goto err_create_file;
469         }
470
471         return 0;
472
473 err_create_file:
474         led_classdev_unregister(&drvdata->led_dev);
475         return err;
476 }
477
478 static int lm3530_remove(struct i2c_client *client)
479 {
480         struct lm3530_data *drvdata = i2c_get_clientdata(client);
481
482         device_remove_file(drvdata->led_dev.dev, &dev_attr_mode);
483
484         lm3530_led_disable(drvdata);
485         led_classdev_unregister(&drvdata->led_dev);
486         return 0;
487 }
488
489 static const struct i2c_device_id lm3530_id[] = {
490         {LM3530_NAME, 0},
491         {}
492 };
493 MODULE_DEVICE_TABLE(i2c, lm3530_id);
494
495 static struct i2c_driver lm3530_i2c_driver = {
496         .probe = lm3530_probe,
497         .remove = lm3530_remove,
498         .id_table = lm3530_id,
499         .driver = {
500                 .name = LM3530_NAME,
501                 .owner = THIS_MODULE,
502         },
503 };
504
505 module_i2c_driver(lm3530_i2c_driver);
506
507 MODULE_DESCRIPTION("Back Light driver for LM3530");
508 MODULE_LICENSE("GPL v2");
509 MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");