2 * Copyright (C) 2011 ST-Ericsson SA.
3 * Copyright (C) 2009 Motorola, Inc.
5 * License Terms: GNU General Public License v2
7 * Simple driver for National Semiconductor LM3530 Backlight driver chip
9 * Author: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>
10 * based on leds-lm3530.c by Dan Murphy <D.Murphy@motorola.com>
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>
22 #define LM3530_LED_DEV "lcd-backlight"
23 #define LM3530_NAME "lm3530-led"
25 #define LM3530_GEN_CONFIG 0x10
26 #define LM3530_ALS_CONFIG 0x20
27 #define LM3530_BRT_RAMP_RATE 0x30
28 #define LM3530_ALS_ZONE_REG 0x40
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 15
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)
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)
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)
60 #define LM3530_ENABLE_ALS (3 << LM3530_EN_ALS_SHIFT)
62 /* Brightness Ramp Rate Register */
63 #define LM3530_BRT_RAMP_FALL_SHIFT (0)
64 #define LM3530_BRT_RAMP_RISE_SHIFT (3)
66 /* ALS Resistor Select */
67 #define LM3530_ALS1_IMP_SHIFT (0)
68 #define LM3530_ALS2_IMP_SHIFT (4)
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)
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)
82 struct lm3530_mode_map {
84 enum lm3530_mode mode_val;
87 static struct lm3530_mode_map mode_map[] = {
88 { "man", LM3530_BL_MODE_MANUAL },
89 { "als", LM3530_BL_MODE_ALS },
90 { "pwm", LM3530_BL_MODE_PWM },
95 * @led_dev: led class device
97 * @pdata: LM3530 platform data
98 * @mode: mode of operation - manual, ALS, PWM
99 * @regulator: regulator
100 * @brighness: previous brightness value
101 * @enable: regulator is enabled
104 struct led_classdev led_dev;
105 struct i2c_client *client;
106 struct lm3530_platform_data *pdata;
107 enum lm3530_mode mode;
108 struct regulator *regulator;
109 enum led_brightness brightness;
113 static const u8 lm3530_reg[LM3530_REG_MAX] = {
116 LM3530_BRT_RAMP_RATE,
118 LM3530_ALS_IMP_SELECT,
131 static int lm3530_get_mode_from_str(const char *str)
135 for (i = 0; i < ARRAY_SIZE(mode_map); i++)
136 if (sysfs_streq(str, mode_map[i].mode))
137 return mode_map[i].mode_val;
142 static int lm3530_init_registers(struct lm3530_data *drvdata)
151 u8 reg_val[LM3530_REG_MAX];
152 u8 zones[LM3530_ALS_ZB_MAX];
153 u32 als_vmin, als_vmax, als_vstep;
154 struct lm3530_platform_data *pltfm = drvdata->pdata;
155 struct i2c_client *client = drvdata->client;
157 gen_config = (pltfm->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) |
158 ((pltfm->max_current & 7) << LM3530_MAX_CURR_SHIFT);
160 if (drvdata->mode == LM3530_BL_MODE_MANUAL ||
161 drvdata->mode == LM3530_BL_MODE_ALS)
162 gen_config |= (LM3530_ENABLE_I2C);
164 if (drvdata->mode == LM3530_BL_MODE_ALS) {
165 if (pltfm->als_vmax == 0) {
166 pltfm->als_vmin = als_vmin = 0;
167 pltfm->als_vmin = als_vmax = LM3530_ALS_WINDOW_mV;
170 als_vmin = pltfm->als_vmin;
171 als_vmax = pltfm->als_vmax;
173 if ((als_vmax - als_vmin) > LM3530_ALS_WINDOW_mV)
174 pltfm->als_vmax = als_vmax =
175 als_vmin + LM3530_ALS_WINDOW_mV;
177 /* n zone boundary makes n+1 zones */
178 als_vstep = (als_vmax - als_vmin) / (LM3530_ALS_ZB_MAX + 1);
180 for (i = 0; i < LM3530_ALS_ZB_MAX; i++)
181 zones[i] = (((als_vmin + LM3530_ALS_OFFSET_mV) +
182 als_vstep + (i * als_vstep)) * LED_FULL)
186 (pltfm->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) |
187 (LM3530_ENABLE_ALS) |
188 (pltfm->als_input_mode << LM3530_ALS_SEL_SHIFT);
191 (pltfm->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) |
192 (pltfm->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);
196 if (drvdata->mode == LM3530_BL_MODE_PWM)
197 gen_config |= (LM3530_ENABLE_PWM) |
198 (pltfm->pwm_pol_hi << LM3530_PWM_POL_SHIFT) |
199 (LM3530_ENABLE_PWM_SIMPLE);
201 brt_ramp = (pltfm->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) |
202 (pltfm->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);
204 if (drvdata->brightness)
205 brightness = drvdata->brightness;
207 brightness = drvdata->brightness = pltfm->brt_val;
209 reg_val[0] = gen_config; /* LM3530_GEN_CONFIG */
210 reg_val[1] = als_config; /* LM3530_ALS_CONFIG */
211 reg_val[2] = brt_ramp; /* LM3530_BRT_RAMP_RATE */
212 reg_val[3] = 0x00; /* LM3530_ALS_ZONE_REG */
213 reg_val[4] = als_imp_sel; /* LM3530_ALS_IMP_SELECT */
214 reg_val[5] = brightness; /* LM3530_BRT_CTRL_REG */
215 reg_val[6] = zones[0]; /* LM3530_ALS_ZB0_REG */
216 reg_val[7] = zones[1]; /* LM3530_ALS_ZB1_REG */
217 reg_val[8] = zones[2]; /* LM3530_ALS_ZB2_REG */
218 reg_val[9] = zones[3]; /* LM3530_ALS_ZB3_REG */
219 reg_val[10] = LM3530_DEF_ZT_0; /* LM3530_ALS_Z0T_REG */
220 reg_val[11] = LM3530_DEF_ZT_1; /* LM3530_ALS_Z1T_REG */
221 reg_val[12] = LM3530_DEF_ZT_2; /* LM3530_ALS_Z2T_REG */
222 reg_val[13] = LM3530_DEF_ZT_3; /* LM3530_ALS_Z3T_REG */
223 reg_val[14] = LM3530_DEF_ZT_4; /* LM3530_ALS_Z4T_REG */
225 if (!drvdata->enable) {
226 ret = regulator_enable(drvdata->regulator);
228 dev_err(&drvdata->client->dev,
229 "Enable regulator failed\n");
232 drvdata->enable = true;
235 for (i = 0; i < LM3530_REG_MAX; i++) {
236 ret = i2c_smbus_write_byte_data(client,
237 lm3530_reg[i], reg_val[i]);
245 static void lm3530_brightness_set(struct led_classdev *led_cdev,
246 enum led_brightness brt_val)
249 struct lm3530_data *drvdata =
250 container_of(led_cdev, struct lm3530_data, led_dev);
252 switch (drvdata->mode) {
253 case LM3530_BL_MODE_MANUAL:
255 if (!drvdata->enable) {
256 err = lm3530_init_registers(drvdata);
258 dev_err(&drvdata->client->dev,
259 "Register Init failed: %d\n", err);
264 /* set the brightness in brightness control register*/
265 err = i2c_smbus_write_byte_data(drvdata->client,
266 LM3530_BRT_CTRL_REG, brt_val / 2);
268 dev_err(&drvdata->client->dev,
269 "Unable to set brightness: %d\n", err);
271 drvdata->brightness = brt_val / 2;
274 err = regulator_disable(drvdata->regulator);
276 dev_err(&drvdata->client->dev,
277 "Disable regulator failed\n");
278 drvdata->enable = false;
281 case LM3530_BL_MODE_ALS:
283 case LM3530_BL_MODE_PWM:
290 static ssize_t lm3530_mode_get(struct device *dev,
291 struct device_attribute *attr, char *buf)
293 struct i2c_client *client = container_of(
294 dev->parent, struct i2c_client, dev);
295 struct lm3530_data *drvdata = i2c_get_clientdata(client);
298 for (i = 0; i < ARRAY_SIZE(mode_map); i++)
299 if (drvdata->mode == mode_map[i].mode_val)
300 len += sprintf(buf + len, "[%s] ", mode_map[i].mode);
302 len += sprintf(buf + len, "%s ", mode_map[i].mode);
304 len += sprintf(buf + len, "\n");
309 static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute
310 *attr, const char *buf, size_t size)
313 struct i2c_client *client = container_of(
314 dev->parent, struct i2c_client, dev);
315 struct lm3530_data *drvdata = i2c_get_clientdata(client);
318 mode = lm3530_get_mode_from_str(buf);
320 dev_err(dev, "Invalid mode\n");
324 if (mode == LM3530_BL_MODE_MANUAL)
325 drvdata->mode = LM3530_BL_MODE_MANUAL;
326 else if (mode == LM3530_BL_MODE_ALS)
327 drvdata->mode = LM3530_BL_MODE_ALS;
328 else if (mode == LM3530_BL_MODE_PWM) {
329 dev_err(dev, "PWM mode not supported\n");
333 err = lm3530_init_registers(drvdata);
335 dev_err(dev, "Setting %s Mode failed :%d\n", buf, err);
339 return sizeof(drvdata->mode);
341 static DEVICE_ATTR(mode, 0644, lm3530_mode_get, lm3530_mode_set);
343 static int __devinit lm3530_probe(struct i2c_client *client,
344 const struct i2c_device_id *id)
346 struct lm3530_platform_data *pdata = client->dev.platform_data;
347 struct lm3530_data *drvdata;
351 dev_err(&client->dev, "platform data required\n");
357 if (pdata->mode > LM3530_BL_MODE_PWM) {
358 dev_err(&client->dev, "Illegal Mode request\n");
363 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
364 dev_err(&client->dev, "I2C_FUNC_I2C not supported\n");
369 drvdata = kzalloc(sizeof(struct lm3530_data), GFP_KERNEL);
370 if (drvdata == NULL) {
375 drvdata->mode = pdata->mode;
376 drvdata->client = client;
377 drvdata->pdata = pdata;
378 drvdata->brightness = LED_OFF;
379 drvdata->enable = false;
380 drvdata->led_dev.name = LM3530_LED_DEV;
381 drvdata->led_dev.brightness_set = lm3530_brightness_set;
383 i2c_set_clientdata(client, drvdata);
385 drvdata->regulator = regulator_get(&client->dev, "vin");
386 if (IS_ERR(drvdata->regulator)) {
387 dev_err(&client->dev, "regulator get failed\n");
388 err = PTR_ERR(drvdata->regulator);
389 drvdata->regulator = NULL;
390 goto err_regulator_get;
393 if (drvdata->pdata->brt_val) {
394 err = lm3530_init_registers(drvdata);
396 dev_err(&client->dev,
397 "Register Init failed: %d\n", err);
402 err = led_classdev_register(&client->dev, &drvdata->led_dev);
404 dev_err(&client->dev, "Register led class failed: %d\n", err);
406 goto err_class_register;
409 err = device_create_file(drvdata->led_dev.dev, &dev_attr_mode);
411 dev_err(&client->dev, "File device creation failed: %d\n", err);
413 goto err_create_file;
419 led_classdev_unregister(&drvdata->led_dev);
422 regulator_put(drvdata->regulator);
429 static int __devexit lm3530_remove(struct i2c_client *client)
431 struct lm3530_data *drvdata = i2c_get_clientdata(client);
433 device_remove_file(drvdata->led_dev.dev, &dev_attr_mode);
436 regulator_disable(drvdata->regulator);
437 regulator_put(drvdata->regulator);
438 led_classdev_unregister(&drvdata->led_dev);
443 static const struct i2c_device_id lm3530_id[] = {
447 MODULE_DEVICE_TABLE(i2c, lm3530_id);
449 static struct i2c_driver lm3530_i2c_driver = {
450 .probe = lm3530_probe,
451 .remove = __devexit_p(lm3530_remove),
452 .id_table = lm3530_id,
455 .owner = THIS_MODULE,
459 static int __init lm3530_init(void)
461 return i2c_add_driver(&lm3530_i2c_driver);
464 static void __exit lm3530_exit(void)
466 i2c_del_driver(&lm3530_i2c_driver);
469 module_init(lm3530_init);
470 module_exit(lm3530_exit);
472 MODULE_DESCRIPTION("Back Light driver for LM3530");
473 MODULE_LICENSE("GPL v2");
474 MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");