tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
83struct lm3530_mode_map {
84 const char *mode;
85 enum lm3530_mode mode_val;
86};
87
88static struct lm3530_mode_map mode_map[] = {
89 { "man", LM3530_BL_MODE_MANUAL },
90 { "als", LM3530_BL_MODE_ALS },
91 { "pwm", LM3530_BL_MODE_PWM },
92};
93
94/**
95 * struct lm3530_data
96 * @led_dev: led class device
97 * @client: i2c client
98 * @pdata: LM3530 platform data
99 * @mode: mode of operation - manual, ALS, PWM
100 * @regulator: regulator
101 * @brighness: previous brightness value
102 * @enable: regulator is enabled
103 */
104struct lm3530_data {
105 struct led_classdev led_dev;
106 struct i2c_client *client;
107 struct lm3530_platform_data *pdata;
108 enum lm3530_mode mode;
109 struct regulator *regulator;
110 enum led_brightness brightness;
111 bool enable;
112};
113
114static const u8 lm3530_reg[LM3530_REG_MAX] = {
115 LM3530_GEN_CONFIG,
116 LM3530_ALS_CONFIG,
117 LM3530_BRT_RAMP_RATE,
118 LM3530_ALS_ZONE_REG,
119 LM3530_ALS_IMP_SELECT,
120 LM3530_BRT_CTRL_REG,
121 LM3530_ALS_ZB0_REG,
122 LM3530_ALS_ZB1_REG,
123 LM3530_ALS_ZB2_REG,
124 LM3530_ALS_ZB3_REG,
125 LM3530_ALS_Z0T_REG,
126 LM3530_ALS_Z1T_REG,
127 LM3530_ALS_Z2T_REG,
128 LM3530_ALS_Z3T_REG,
129 LM3530_ALS_Z4T_REG,
130};
131
132static int lm3530_get_mode_from_str(const char *str)
133{
134 int i;
135
136 for (i = 0; i < ARRAY_SIZE(mode_map); i++)
137 if (sysfs_streq(str, mode_map[i].mode))
138 return mode_map[i].mode_val;
139
140 return -1;
141}
142
143static int lm3530_init_registers(struct lm3530_data *drvdata)
144{
145 int ret = 0;
146 int i;
147 u8 gen_config;
148 u8 als_config = 0;
149 u8 brt_ramp;
150 u8 als_imp_sel = 0;
151 u8 brightness;
152 u8 reg_val[LM3530_REG_MAX];
153 u8 zones[LM3530_ALS_ZB_MAX];
154 u32 als_vmin, als_vmax, als_vstep;
155 struct lm3530_platform_data *pltfm = drvdata->pdata;
156 struct i2c_client *client = drvdata->client;
157
158 gen_config = (pltfm->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) |
159 ((pltfm->max_current & 7) << LM3530_MAX_CURR_SHIFT);
160
161 if (drvdata->mode == LM3530_BL_MODE_MANUAL ||
162 drvdata->mode == LM3530_BL_MODE_ALS)
163 gen_config |= (LM3530_ENABLE_I2C);
164
165 if (drvdata->mode == LM3530_BL_MODE_ALS) {
166 if (pltfm->als_vmax == 0) {
167 pltfm->als_vmin = als_vmin = 0;
168 pltfm->als_vmin = als_vmax = LM3530_ALS_WINDOW_mV;
169 }
170
171 als_vmin = pltfm->als_vmin;
172 als_vmax = pltfm->als_vmax;
173
174 if ((als_vmax - als_vmin) > LM3530_ALS_WINDOW_mV)
175 pltfm->als_vmax = als_vmax =
176 als_vmin + LM3530_ALS_WINDOW_mV;
177
178 /* n zone boundary makes n+1 zones */
179 als_vstep = (als_vmax - als_vmin) / (LM3530_ALS_ZB_MAX + 1);
180
181 for (i = 0; i < LM3530_ALS_ZB_MAX; i++)
182 zones[i] = (((als_vmin + LM3530_ALS_OFFSET_mV) +
183 als_vstep + (i * als_vstep)) * LED_FULL)
184 / 1000;
185
186 als_config =
187 (pltfm->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) |
188 (LM3530_ENABLE_ALS) |
189 (pltfm->als_input_mode << LM3530_ALS_SEL_SHIFT);
190
191 als_imp_sel =
192 (pltfm->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) |
193 (pltfm->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);
194
195 }
196
197 if (drvdata->mode == LM3530_BL_MODE_PWM)
198 gen_config |= (LM3530_ENABLE_PWM) |
199 (pltfm->pwm_pol_hi << LM3530_PWM_POL_SHIFT) |
200 (LM3530_ENABLE_PWM_SIMPLE);
201
202 brt_ramp = (pltfm->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) |
203 (pltfm->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);
204
205 if (drvdata->brightness)
206 brightness = drvdata->brightness;
207 else
208 brightness = drvdata->brightness = pltfm->brt_val;
209
210 reg_val[0] = gen_config; /* LM3530_GEN_CONFIG */
211 reg_val[1] = als_config; /* LM3530_ALS_CONFIG */
212 reg_val[2] = brt_ramp; /* LM3530_BRT_RAMP_RATE */
213 reg_val[3] = 0x00; /* LM3530_ALS_ZONE_REG */
214 reg_val[4] = als_imp_sel; /* LM3530_ALS_IMP_SELECT */
215 reg_val[5] = brightness; /* LM3530_BRT_CTRL_REG */
216 reg_val[6] = zones[0]; /* LM3530_ALS_ZB0_REG */
217 reg_val[7] = zones[1]; /* LM3530_ALS_ZB1_REG */
218 reg_val[8] = zones[2]; /* LM3530_ALS_ZB2_REG */
219 reg_val[9] = zones[3]; /* LM3530_ALS_ZB3_REG */
220 reg_val[10] = LM3530_DEF_ZT_0; /* LM3530_ALS_Z0T_REG */
221 reg_val[11] = LM3530_DEF_ZT_1; /* LM3530_ALS_Z1T_REG */
222 reg_val[12] = LM3530_DEF_ZT_2; /* LM3530_ALS_Z2T_REG */
223 reg_val[13] = LM3530_DEF_ZT_3; /* LM3530_ALS_Z3T_REG */
224 reg_val[14] = LM3530_DEF_ZT_4; /* LM3530_ALS_Z4T_REG */
225
226 if (!drvdata->enable) {
227 ret = regulator_enable(drvdata->regulator);
228 if (ret) {
229 dev_err(&drvdata->client->dev,
230 "Enable regulator failed\n");
231 return ret;
232 }
233 drvdata->enable = true;
234 }
235
236 for (i = 0; i < LM3530_REG_MAX; i++) {
237 ret = i2c_smbus_write_byte_data(client,
238 lm3530_reg[i], reg_val[i]);
239 if (ret)
240 break;
241 }
242
243 return ret;
244}
245
246static void lm3530_brightness_set(struct led_classdev *led_cdev,
247 enum led_brightness brt_val)
248{
249 int err;
250 struct lm3530_data *drvdata =
251 container_of(led_cdev, struct lm3530_data, led_dev);
252
253 switch (drvdata->mode) {
254 case LM3530_BL_MODE_MANUAL:
255
256 if (!drvdata->enable) {
257 err = lm3530_init_registers(drvdata);
258 if (err) {
259 dev_err(&drvdata->client->dev,
260 "Register Init failed: %d\n", err);
261 break;
262 }
263 }
264
265 /* set the brightness in brightness control register*/
266 err = i2c_smbus_write_byte_data(drvdata->client,
267 LM3530_BRT_CTRL_REG, brt_val / 2);
268 if (err)
269 dev_err(&drvdata->client->dev,
270 "Unable to set brightness: %d\n", err);
271 else
272 drvdata->brightness = brt_val / 2;
273
274 if (brt_val == 0) {
275 err = regulator_disable(drvdata->regulator);
276 if (err)
277 dev_err(&drvdata->client->dev,
278 "Disable regulator failed\n");
279 drvdata->enable = false;
280 }
281 break;
282 case LM3530_BL_MODE_ALS:
283 break;
284 case LM3530_BL_MODE_PWM:
285 break;
286 default:
287 break;
288 }
289}
290
291static ssize_t lm3530_mode_get(struct device *dev,
292 struct device_attribute *attr, char *buf)
293{
294 struct i2c_client *client = container_of(
295 dev->parent, struct i2c_client, dev);
296 struct lm3530_data *drvdata = i2c_get_clientdata(client);
297 int i, len = 0;
298
299 for (i = 0; i < ARRAY_SIZE(mode_map); i++)
300 if (drvdata->mode == mode_map[i].mode_val)
301 len += sprintf(buf + len, "[%s] ", mode_map[i].mode);
302 else
303 len += sprintf(buf + len, "%s ", mode_map[i].mode);
304
305 len += sprintf(buf + len, "\n");
306
307 return len;
308}
309
310static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute
311 *attr, const char *buf, size_t size)
312{
313 int err;
314 struct i2c_client *client = container_of(
315 dev->parent, struct i2c_client, dev);
316 struct lm3530_data *drvdata = i2c_get_clientdata(client);
317 int mode;
318
319 mode = lm3530_get_mode_from_str(buf);
320 if (mode < 0) {
321 dev_err(dev, "Invalid mode\n");
322 return -EINVAL;
323 }
324
325 if (mode == LM3530_BL_MODE_MANUAL)
326 drvdata->mode = LM3530_BL_MODE_MANUAL;
327 else if (mode == LM3530_BL_MODE_ALS)
328 drvdata->mode = LM3530_BL_MODE_ALS;
329 else if (mode == LM3530_BL_MODE_PWM) {
330 dev_err(dev, "PWM mode not supported\n");
331 return -EINVAL;
332 }
333
334 err = lm3530_init_registers(drvdata);
335 if (err) {
336 dev_err(dev, "Setting %s Mode failed :%d\n", buf, err);
337 return err;
338 }
339
340 return sizeof(drvdata->mode);
341}
342static DEVICE_ATTR(mode, 0644, lm3530_mode_get, lm3530_mode_set);
343
344static int __devinit lm3530_probe(struct i2c_client *client,
345 const struct i2c_device_id *id)
346{
347 struct lm3530_platform_data *pdata = client->dev.platform_data;
348 struct lm3530_data *drvdata;
349 int err = 0;
350
351 if (pdata == NULL) {
352 dev_err(&client->dev, "platform data required\n");
353 err = -ENODEV;
354 goto err_out;
355 }
356
357 /* BL mode */
358 if (pdata->mode > LM3530_BL_MODE_PWM) {
359 dev_err(&client->dev, "Illegal Mode request\n");
360 err = -EINVAL;
361 goto err_out;
362 }
363
364 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
365 dev_err(&client->dev, "I2C_FUNC_I2C not supported\n");
366 err = -EIO;
367 goto err_out;
368 }
369
370 drvdata = kzalloc(sizeof(struct lm3530_data), GFP_KERNEL);
371 if (drvdata == NULL) {
372 err = -ENOMEM;
373 goto err_out;
374 }
375
376 drvdata->mode = pdata->mode;
377 drvdata->client = client;
378 drvdata->pdata = pdata;
379 drvdata->brightness = LED_OFF;
380 drvdata->enable = false;
381 drvdata->led_dev.name = LM3530_LED_DEV;
382 drvdata->led_dev.brightness_set = lm3530_brightness_set;
383
384 i2c_set_clientdata(client, drvdata);
385
386 drvdata->regulator = regulator_get(&client->dev, "vin");
387 if (IS_ERR(drvdata->regulator)) {
388 dev_err(&client->dev, "regulator get failed\n");
389 err = PTR_ERR(drvdata->regulator);
390 drvdata->regulator = NULL;
391 goto err_regulator_get;
392 }
393
394 if (drvdata->pdata->brt_val) {
395 err = lm3530_init_registers(drvdata);
396 if (err < 0) {
397 dev_err(&client->dev,
398 "Register Init failed: %d\n", err);
399 err = -ENODEV;
400 goto err_reg_init;
401 }
402 }
403 err = led_classdev_register(&client->dev, &drvdata->led_dev);
404 if (err < 0) {
405 dev_err(&client->dev, "Register led class failed: %d\n", err);
406 err = -ENODEV;
407 goto err_class_register;
408 }
409
410 err = device_create_file(drvdata->led_dev.dev, &dev_attr_mode);
411 if (err < 0) {
412 dev_err(&client->dev, "File device creation failed: %d\n", err);
413 err = -ENODEV;
414 goto err_create_file;
415 }
416
417 return 0;
418
419err_create_file:
420 led_classdev_unregister(&drvdata->led_dev);
421err_class_register:
422err_reg_init:
423 regulator_put(drvdata->regulator);
424err_regulator_get:
425 kfree(drvdata);
426err_out:
427 return err;
428}
429
430static int __devexit lm3530_remove(struct i2c_client *client)
431{
432 struct lm3530_data *drvdata = i2c_get_clientdata(client);
433
434 device_remove_file(drvdata->led_dev.dev, &dev_attr_mode);
435
436 if (drvdata->enable)
437 regulator_disable(drvdata->regulator);
438 regulator_put(drvdata->regulator);
439 led_classdev_unregister(&drvdata->led_dev);
440 kfree(drvdata);
441 return 0;
442}
443
444static const struct i2c_device_id lm3530_id[] = {
445 {LM3530_NAME, 0},
446 {}
447};
448MODULE_DEVICE_TABLE(i2c, lm3530_id);
449
450static struct i2c_driver lm3530_i2c_driver = {
451 .probe = lm3530_probe,
452 .remove = __devexit_p(lm3530_remove),
453 .id_table = lm3530_id,
454 .driver = {
455 .name = LM3530_NAME,
456 .owner = THIS_MODULE,
457 },
458};
459
460static int __init lm3530_init(void)
461{
462 return i2c_add_driver(&lm3530_i2c_driver);
463}
464
465static void __exit lm3530_exit(void)
466{
467 i2c_del_driver(&lm3530_i2c_driver);
468}
469
470module_init(lm3530_init);
471module_exit(lm3530_exit);
472
473MODULE_DESCRIPTION("Back Light driver for LM3530");
474MODULE_LICENSE("GPL v2");
475MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");