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leds-lm3530: support pwm input mode
[deliverable/linux.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_ZONE_REG 0x40
30 #define LM3530_ALS_IMP_SELECT 0x41
31 #define LM3530_BRT_CTRL_REG 0xA0
32 #define LM3530_ALS_ZB0_REG 0x60
33 #define LM3530_ALS_ZB1_REG 0x61
34 #define LM3530_ALS_ZB2_REG 0x62
35 #define LM3530_ALS_ZB3_REG 0x63
36 #define LM3530_ALS_Z0T_REG 0x70
37 #define LM3530_ALS_Z1T_REG 0x71
38 #define LM3530_ALS_Z2T_REG 0x72
39 #define LM3530_ALS_Z3T_REG 0x73
40 #define LM3530_ALS_Z4T_REG 0x74
41 #define LM3530_REG_MAX 15
42
43 /* General Control Register */
44 #define LM3530_EN_I2C_SHIFT (0)
45 #define LM3530_RAMP_LAW_SHIFT (1)
46 #define LM3530_MAX_CURR_SHIFT (2)
47 #define LM3530_EN_PWM_SHIFT (5)
48 #define LM3530_PWM_POL_SHIFT (6)
49 #define LM3530_EN_PWM_SIMPLE_SHIFT (7)
50
51 #define LM3530_ENABLE_I2C (1 << LM3530_EN_I2C_SHIFT)
52 #define LM3530_ENABLE_PWM (1 << LM3530_EN_PWM_SHIFT)
53 #define LM3530_POL_LOW (1 << LM3530_PWM_POL_SHIFT)
54 #define LM3530_ENABLE_PWM_SIMPLE (1 << LM3530_EN_PWM_SIMPLE_SHIFT)
55
56 /* ALS Config Register Options */
57 #define LM3530_ALS_AVG_TIME_SHIFT (0)
58 #define LM3530_EN_ALS_SHIFT (3)
59 #define LM3530_ALS_SEL_SHIFT (5)
60
61 #define LM3530_ENABLE_ALS (3 << LM3530_EN_ALS_SHIFT)
62
63 /* Brightness Ramp Rate Register */
64 #define LM3530_BRT_RAMP_FALL_SHIFT (0)
65 #define LM3530_BRT_RAMP_RISE_SHIFT (3)
66
67 /* ALS Resistor Select */
68 #define LM3530_ALS1_IMP_SHIFT (0)
69 #define LM3530_ALS2_IMP_SHIFT (4)
70
71 /* Zone Boundary Register defaults */
72 #define LM3530_ALS_ZB_MAX (4)
73 #define LM3530_ALS_WINDOW_mV (1000)
74 #define LM3530_ALS_OFFSET_mV (4)
75
76 /* Zone Target Register defaults */
77 #define LM3530_DEF_ZT_0 (0x7F)
78 #define LM3530_DEF_ZT_1 (0x66)
79 #define LM3530_DEF_ZT_2 (0x4C)
80 #define LM3530_DEF_ZT_3 (0x33)
81 #define LM3530_DEF_ZT_4 (0x19)
82
83 /* 7 bits are used for the brightness : LM3530_BRT_CTRL_REG */
84 #define MAX_BRIGHTNESS (127)
85
86 struct lm3530_mode_map {
87 const char *mode;
88 enum lm3530_mode mode_val;
89 };
90
91 static struct lm3530_mode_map mode_map[] = {
92 { "man", LM3530_BL_MODE_MANUAL },
93 { "als", LM3530_BL_MODE_ALS },
94 { "pwm", LM3530_BL_MODE_PWM },
95 };
96
97 /**
98 * struct lm3530_data
99 * @led_dev: led class device
100 * @client: i2c client
101 * @pdata: LM3530 platform data
102 * @mode: mode of operation - manual, ALS, PWM
103 * @regulator: regulator
104 * @brighness: previous brightness value
105 * @enable: regulator is enabled
106 */
107 struct lm3530_data {
108 struct led_classdev led_dev;
109 struct i2c_client *client;
110 struct lm3530_platform_data *pdata;
111 enum lm3530_mode mode;
112 struct regulator *regulator;
113 enum led_brightness brightness;
114 bool enable;
115 };
116
117 static const u8 lm3530_reg[LM3530_REG_MAX] = {
118 LM3530_GEN_CONFIG,
119 LM3530_ALS_CONFIG,
120 LM3530_BRT_RAMP_RATE,
121 LM3530_ALS_ZONE_REG,
122 LM3530_ALS_IMP_SELECT,
123 LM3530_BRT_CTRL_REG,
124 LM3530_ALS_ZB0_REG,
125 LM3530_ALS_ZB1_REG,
126 LM3530_ALS_ZB2_REG,
127 LM3530_ALS_ZB3_REG,
128 LM3530_ALS_Z0T_REG,
129 LM3530_ALS_Z1T_REG,
130 LM3530_ALS_Z2T_REG,
131 LM3530_ALS_Z3T_REG,
132 LM3530_ALS_Z4T_REG,
133 };
134
135 static int lm3530_get_mode_from_str(const char *str)
136 {
137 int i;
138
139 for (i = 0; i < ARRAY_SIZE(mode_map); i++)
140 if (sysfs_streq(str, mode_map[i].mode))
141 return mode_map[i].mode_val;
142
143 return -1;
144 }
145
146 static int lm3530_init_registers(struct lm3530_data *drvdata)
147 {
148 int ret = 0;
149 int i;
150 u8 gen_config;
151 u8 als_config = 0;
152 u8 brt_ramp;
153 u8 als_imp_sel = 0;
154 u8 brightness;
155 u8 reg_val[LM3530_REG_MAX];
156 u8 zones[LM3530_ALS_ZB_MAX];
157 u32 als_vmin, als_vmax, als_vstep;
158 struct lm3530_platform_data *pltfm = drvdata->pdata;
159 struct i2c_client *client = drvdata->client;
160 struct lm3530_pwm_data *pwm = &pltfm->pwm_data;
161
162 gen_config = (pltfm->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) |
163 ((pltfm->max_current & 7) << LM3530_MAX_CURR_SHIFT);
164
165 if (drvdata->mode == LM3530_BL_MODE_MANUAL ||
166 drvdata->mode == LM3530_BL_MODE_ALS)
167 gen_config |= (LM3530_ENABLE_I2C);
168
169 if (drvdata->mode == LM3530_BL_MODE_ALS) {
170 if (pltfm->als_vmax == 0) {
171 pltfm->als_vmin = 0;
172 pltfm->als_vmax = LM3530_ALS_WINDOW_mV;
173 }
174
175 als_vmin = pltfm->als_vmin;
176 als_vmax = pltfm->als_vmax;
177
178 if ((als_vmax - als_vmin) > LM3530_ALS_WINDOW_mV)
179 pltfm->als_vmax = als_vmax =
180 als_vmin + LM3530_ALS_WINDOW_mV;
181
182 /* n zone boundary makes n+1 zones */
183 als_vstep = (als_vmax - als_vmin) / (LM3530_ALS_ZB_MAX + 1);
184
185 for (i = 0; i < LM3530_ALS_ZB_MAX; i++)
186 zones[i] = (((als_vmin + LM3530_ALS_OFFSET_mV) +
187 als_vstep + (i * als_vstep)) * LED_FULL)
188 / 1000;
189
190 als_config =
191 (pltfm->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) |
192 (LM3530_ENABLE_ALS) |
193 (pltfm->als_input_mode << LM3530_ALS_SEL_SHIFT);
194
195 als_imp_sel =
196 (pltfm->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) |
197 (pltfm->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);
198
199 }
200
201 if (drvdata->mode == LM3530_BL_MODE_PWM)
202 gen_config |= (LM3530_ENABLE_PWM) |
203 (pltfm->pwm_pol_hi << LM3530_PWM_POL_SHIFT) |
204 (LM3530_ENABLE_PWM_SIMPLE);
205
206 brt_ramp = (pltfm->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) |
207 (pltfm->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);
208
209 if (drvdata->brightness)
210 brightness = drvdata->brightness;
211 else
212 brightness = drvdata->brightness = pltfm->brt_val;
213
214 if (brightness > drvdata->led_dev.max_brightness)
215 brightness = drvdata->led_dev.max_brightness;
216
217 reg_val[0] = gen_config; /* LM3530_GEN_CONFIG */
218 reg_val[1] = als_config; /* LM3530_ALS_CONFIG */
219 reg_val[2] = brt_ramp; /* LM3530_BRT_RAMP_RATE */
220 reg_val[3] = 0x00; /* LM3530_ALS_ZONE_REG */
221 reg_val[4] = als_imp_sel; /* LM3530_ALS_IMP_SELECT */
222 reg_val[5] = brightness; /* LM3530_BRT_CTRL_REG */
223 reg_val[6] = zones[0]; /* LM3530_ALS_ZB0_REG */
224 reg_val[7] = zones[1]; /* LM3530_ALS_ZB1_REG */
225 reg_val[8] = zones[2]; /* LM3530_ALS_ZB2_REG */
226 reg_val[9] = zones[3]; /* LM3530_ALS_ZB3_REG */
227 reg_val[10] = LM3530_DEF_ZT_0; /* LM3530_ALS_Z0T_REG */
228 reg_val[11] = LM3530_DEF_ZT_1; /* LM3530_ALS_Z1T_REG */
229 reg_val[12] = LM3530_DEF_ZT_2; /* LM3530_ALS_Z2T_REG */
230 reg_val[13] = LM3530_DEF_ZT_3; /* LM3530_ALS_Z3T_REG */
231 reg_val[14] = LM3530_DEF_ZT_4; /* LM3530_ALS_Z4T_REG */
232
233 if (!drvdata->enable) {
234 ret = regulator_enable(drvdata->regulator);
235 if (ret) {
236 dev_err(&drvdata->client->dev,
237 "Enable regulator failed\n");
238 return ret;
239 }
240 drvdata->enable = true;
241 }
242
243 for (i = 0; i < LM3530_REG_MAX; i++) {
244 /* do not update brightness register when pwm mode */
245 if (lm3530_reg[i] == LM3530_BRT_CTRL_REG &&
246 drvdata->mode == LM3530_BL_MODE_PWM) {
247 if (pwm->pwm_set_intensity)
248 pwm->pwm_set_intensity(reg_val[i],
249 drvdata->led_dev.max_brightness);
250 continue;
251 }
252
253 ret = i2c_smbus_write_byte_data(client,
254 lm3530_reg[i], reg_val[i]);
255 if (ret)
256 break;
257 }
258
259 return ret;
260 }
261
262 static void lm3530_brightness_set(struct led_classdev *led_cdev,
263 enum led_brightness brt_val)
264 {
265 int err;
266 struct lm3530_data *drvdata =
267 container_of(led_cdev, struct lm3530_data, led_dev);
268 struct lm3530_platform_data *pdata = drvdata->pdata;
269 struct lm3530_pwm_data *pwm = &pdata->pwm_data;
270 u8 max_brightness = led_cdev->max_brightness;
271
272 switch (drvdata->mode) {
273 case LM3530_BL_MODE_MANUAL:
274
275 if (!drvdata->enable) {
276 err = lm3530_init_registers(drvdata);
277 if (err) {
278 dev_err(&drvdata->client->dev,
279 "Register Init failed: %d\n", err);
280 break;
281 }
282 }
283
284 /* set the brightness in brightness control register*/
285 err = i2c_smbus_write_byte_data(drvdata->client,
286 LM3530_BRT_CTRL_REG, brt_val);
287 if (err)
288 dev_err(&drvdata->client->dev,
289 "Unable to set brightness: %d\n", err);
290 else
291 drvdata->brightness = brt_val;
292
293 if (brt_val == 0) {
294 err = regulator_disable(drvdata->regulator);
295 if (err)
296 dev_err(&drvdata->client->dev,
297 "Disable regulator failed\n");
298 drvdata->enable = false;
299 }
300 break;
301 case LM3530_BL_MODE_ALS:
302 break;
303 case LM3530_BL_MODE_PWM:
304 if (pwm->pwm_set_intensity)
305 pwm->pwm_set_intensity(brt_val, max_brightness);
306 break;
307 default:
308 break;
309 }
310 }
311
312 static ssize_t lm3530_mode_get(struct device *dev,
313 struct device_attribute *attr, char *buf)
314 {
315 struct led_classdev *led_cdev = dev_get_drvdata(dev);
316 struct lm3530_data *drvdata;
317 int i, len = 0;
318
319 drvdata = container_of(led_cdev, struct lm3530_data, led_dev);
320 for (i = 0; i < ARRAY_SIZE(mode_map); i++)
321 if (drvdata->mode == mode_map[i].mode_val)
322 len += sprintf(buf + len, "[%s] ", mode_map[i].mode);
323 else
324 len += sprintf(buf + len, "%s ", mode_map[i].mode);
325
326 len += sprintf(buf + len, "\n");
327
328 return len;
329 }
330
331 static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute
332 *attr, const char *buf, size_t size)
333 {
334 struct led_classdev *led_cdev = dev_get_drvdata(dev);
335 struct lm3530_data *drvdata;
336 struct lm3530_pwm_data *pwm;
337 u8 max_brightness;
338 int mode, err;
339
340 drvdata = container_of(led_cdev, struct lm3530_data, led_dev);
341 pwm = &drvdata->pdata->pwm_data;
342 max_brightness = led_cdev->max_brightness;
343 mode = lm3530_get_mode_from_str(buf);
344 if (mode < 0) {
345 dev_err(dev, "Invalid mode\n");
346 return -EINVAL;
347 }
348
349 drvdata->mode = mode;
350
351 /* set pwm to low if unnecessary */
352 if (mode != LM3530_BL_MODE_PWM && pwm->pwm_set_intensity)
353 pwm->pwm_set_intensity(0, max_brightness);
354
355 err = lm3530_init_registers(drvdata);
356 if (err) {
357 dev_err(dev, "Setting %s Mode failed :%d\n", buf, err);
358 return err;
359 }
360
361 return sizeof(drvdata->mode);
362 }
363 static DEVICE_ATTR(mode, 0644, lm3530_mode_get, lm3530_mode_set);
364
365 static int __devinit lm3530_probe(struct i2c_client *client,
366 const struct i2c_device_id *id)
367 {
368 struct lm3530_platform_data *pdata = client->dev.platform_data;
369 struct lm3530_data *drvdata;
370 int err = 0;
371
372 if (pdata == NULL) {
373 dev_err(&client->dev, "platform data required\n");
374 err = -ENODEV;
375 goto err_out;
376 }
377
378 /* BL mode */
379 if (pdata->mode > LM3530_BL_MODE_PWM) {
380 dev_err(&client->dev, "Illegal Mode request\n");
381 err = -EINVAL;
382 goto err_out;
383 }
384
385 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
386 dev_err(&client->dev, "I2C_FUNC_I2C not supported\n");
387 err = -EIO;
388 goto err_out;
389 }
390
391 drvdata = kzalloc(sizeof(struct lm3530_data), GFP_KERNEL);
392 if (drvdata == NULL) {
393 err = -ENOMEM;
394 goto err_out;
395 }
396
397 drvdata->mode = pdata->mode;
398 drvdata->client = client;
399 drvdata->pdata = pdata;
400 drvdata->brightness = LED_OFF;
401 drvdata->enable = false;
402 drvdata->led_dev.name = LM3530_LED_DEV;
403 drvdata->led_dev.brightness_set = lm3530_brightness_set;
404 drvdata->led_dev.max_brightness = MAX_BRIGHTNESS;
405
406 i2c_set_clientdata(client, drvdata);
407
408 drvdata->regulator = regulator_get(&client->dev, "vin");
409 if (IS_ERR(drvdata->regulator)) {
410 dev_err(&client->dev, "regulator get failed\n");
411 err = PTR_ERR(drvdata->regulator);
412 drvdata->regulator = NULL;
413 goto err_regulator_get;
414 }
415
416 if (drvdata->pdata->brt_val) {
417 err = lm3530_init_registers(drvdata);
418 if (err < 0) {
419 dev_err(&client->dev,
420 "Register Init failed: %d\n", err);
421 err = -ENODEV;
422 goto err_reg_init;
423 }
424 }
425 err = led_classdev_register(&client->dev, &drvdata->led_dev);
426 if (err < 0) {
427 dev_err(&client->dev, "Register led class failed: %d\n", err);
428 err = -ENODEV;
429 goto err_class_register;
430 }
431
432 err = device_create_file(drvdata->led_dev.dev, &dev_attr_mode);
433 if (err < 0) {
434 dev_err(&client->dev, "File device creation failed: %d\n", err);
435 err = -ENODEV;
436 goto err_create_file;
437 }
438
439 return 0;
440
441 err_create_file:
442 led_classdev_unregister(&drvdata->led_dev);
443 err_class_register:
444 err_reg_init:
445 regulator_put(drvdata->regulator);
446 err_regulator_get:
447 kfree(drvdata);
448 err_out:
449 return err;
450 }
451
452 static int __devexit lm3530_remove(struct i2c_client *client)
453 {
454 struct lm3530_data *drvdata = i2c_get_clientdata(client);
455
456 device_remove_file(drvdata->led_dev.dev, &dev_attr_mode);
457
458 if (drvdata->enable)
459 regulator_disable(drvdata->regulator);
460 regulator_put(drvdata->regulator);
461 led_classdev_unregister(&drvdata->led_dev);
462 kfree(drvdata);
463 return 0;
464 }
465
466 static const struct i2c_device_id lm3530_id[] = {
467 {LM3530_NAME, 0},
468 {}
469 };
470 MODULE_DEVICE_TABLE(i2c, lm3530_id);
471
472 static struct i2c_driver lm3530_i2c_driver = {
473 .probe = lm3530_probe,
474 .remove = __devexit_p(lm3530_remove),
475 .id_table = lm3530_id,
476 .driver = {
477 .name = LM3530_NAME,
478 .owner = THIS_MODULE,
479 },
480 };
481
482 module_i2c_driver(lm3530_i2c_driver);
483
484 MODULE_DESCRIPTION("Back Light driver for LM3530");
485 MODULE_LICENSE("GPL v2");
486 MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");
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