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_DEF_ZB_0 (0x33)
72 #define LM3530_DEF_ZB_1 (0x66)
73 #define LM3530_DEF_ZB_2 (0x99)
74 #define LM3530_DEF_ZB_3 (0xCC)
76 /* Zone Target Register defaults */
77 #define LM3530_DEF_ZT_0 (0x19)
78 #define LM3530_DEF_ZT_1 (0x33)
79 #define LM3530_DEF_ZT_2 (0x4C)
80 #define LM3530_DEF_ZT_3 (0x66)
81 #define LM3530_DEF_ZT_4 (0x7F)
83 struct lm3530_mode_map {
85 enum lm3530_mode mode_val;
88 static struct lm3530_mode_map mode_map[] = {
89 { "man", LM3530_BL_MODE_MANUAL },
90 { "als", LM3530_BL_MODE_ALS },
91 { "pwm", LM3530_BL_MODE_PWM },
96 * @led_dev: led class device
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
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;
114 static const u8 lm3530_reg[LM3530_REG_MAX] = {
117 LM3530_BRT_RAMP_RATE,
119 LM3530_ALS_IMP_SELECT,
132 static int lm3530_get_mode_from_str(const char *str)
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;
143 static int lm3530_init_registers(struct lm3530_data *drvdata)
152 u8 reg_val[LM3530_REG_MAX];
153 struct lm3530_platform_data *pltfm = drvdata->pdata;
154 struct i2c_client *client = drvdata->client;
156 gen_config = (pltfm->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) |
157 ((pltfm->max_current & 7) << LM3530_MAX_CURR_SHIFT);
159 if (drvdata->mode == LM3530_BL_MODE_MANUAL ||
160 drvdata->mode == LM3530_BL_MODE_ALS)
161 gen_config |= (LM3530_ENABLE_I2C);
163 if (drvdata->mode == LM3530_BL_MODE_ALS) {
165 (pltfm->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) |
166 (LM3530_ENABLE_ALS) |
167 (pltfm->als_input_mode << LM3530_ALS_SEL_SHIFT);
170 (pltfm->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) |
171 (pltfm->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);
174 if (drvdata->mode == LM3530_BL_MODE_PWM)
175 gen_config |= (LM3530_ENABLE_PWM) |
176 (pltfm->pwm_pol_hi << LM3530_PWM_POL_SHIFT) |
177 (LM3530_ENABLE_PWM_SIMPLE);
179 brt_ramp = (pltfm->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) |
180 (pltfm->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);
182 if (drvdata->brightness)
183 brightness = drvdata->brightness;
185 brightness = drvdata->brightness = pltfm->brt_val;
187 reg_val[0] = gen_config; /* LM3530_GEN_CONFIG */
188 reg_val[1] = als_config; /* LM3530_ALS_CONFIG */
189 reg_val[2] = brt_ramp; /* LM3530_BRT_RAMP_RATE */
190 reg_val[3] = 0x00; /* LM3530_ALS_ZONE_REG */
191 reg_val[4] = als_imp_sel; /* LM3530_ALS_IMP_SELECT */
192 reg_val[5] = brightness; /* LM3530_BRT_CTRL_REG */
193 reg_val[6] = LM3530_DEF_ZB_0; /* LM3530_ALS_ZB0_REG */
194 reg_val[7] = LM3530_DEF_ZB_1; /* LM3530_ALS_ZB1_REG */
195 reg_val[8] = LM3530_DEF_ZB_2; /* LM3530_ALS_ZB2_REG */
196 reg_val[9] = LM3530_DEF_ZB_3; /* LM3530_ALS_ZB3_REG */
197 reg_val[10] = LM3530_DEF_ZT_0; /* LM3530_ALS_Z0T_REG */
198 reg_val[11] = LM3530_DEF_ZT_1; /* LM3530_ALS_Z1T_REG */
199 reg_val[12] = LM3530_DEF_ZT_2; /* LM3530_ALS_Z2T_REG */
200 reg_val[13] = LM3530_DEF_ZT_3; /* LM3530_ALS_Z3T_REG */
201 reg_val[14] = LM3530_DEF_ZT_4; /* LM3530_ALS_Z4T_REG */
203 if (!drvdata->enable) {
204 ret = regulator_enable(drvdata->regulator);
206 dev_err(&drvdata->client->dev,
207 "Enable regulator failed\n");
210 drvdata->enable = true;
213 for (i = 0; i < LM3530_REG_MAX; i++) {
214 ret = i2c_smbus_write_byte_data(client,
215 lm3530_reg[i], reg_val[i]);
223 static void lm3530_brightness_set(struct led_classdev *led_cdev,
224 enum led_brightness brt_val)
227 struct lm3530_data *drvdata =
228 container_of(led_cdev, struct lm3530_data, led_dev);
230 switch (drvdata->mode) {
231 case LM3530_BL_MODE_MANUAL:
233 if (!drvdata->enable) {
234 err = lm3530_init_registers(drvdata);
236 dev_err(&drvdata->client->dev,
237 "Register Init failed: %d\n", err);
242 /* set the brightness in brightness control register*/
243 err = i2c_smbus_write_byte_data(drvdata->client,
244 LM3530_BRT_CTRL_REG, brt_val / 2);
246 dev_err(&drvdata->client->dev,
247 "Unable to set brightness: %d\n", err);
249 drvdata->brightness = brt_val / 2;
252 err = regulator_disable(drvdata->regulator);
254 dev_err(&drvdata->client->dev,
255 "Disable regulator failed\n");
256 drvdata->enable = false;
259 case LM3530_BL_MODE_ALS:
261 case LM3530_BL_MODE_PWM:
269 static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute
270 *attr, const char *buf, size_t size)
273 struct i2c_client *client = container_of(
274 dev->parent, struct i2c_client, dev);
275 struct lm3530_data *drvdata = i2c_get_clientdata(client);
278 mode = lm3530_get_mode_from_str(buf);
280 dev_err(dev, "Invalid mode\n");
284 if (mode == LM3530_BL_MODE_MANUAL)
285 drvdata->mode = LM3530_BL_MODE_MANUAL;
286 else if (mode == LM3530_BL_MODE_ALS)
287 drvdata->mode = LM3530_BL_MODE_ALS;
288 else if (mode == LM3530_BL_MODE_PWM) {
289 dev_err(dev, "PWM mode not supported\n");
293 err = lm3530_init_registers(drvdata);
295 dev_err(dev, "Setting %s Mode failed :%d\n", buf, err);
299 return sizeof(drvdata->mode);
302 static DEVICE_ATTR(mode, 0644, NULL, lm3530_mode_set);
304 static int __devinit lm3530_probe(struct i2c_client *client,
305 const struct i2c_device_id *id)
307 struct lm3530_platform_data *pdata = client->dev.platform_data;
308 struct lm3530_data *drvdata;
312 dev_err(&client->dev, "platform data required\n");
318 if (pdata->mode > LM3530_BL_MODE_PWM) {
319 dev_err(&client->dev, "Illegal Mode request\n");
324 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
325 dev_err(&client->dev, "I2C_FUNC_I2C not supported\n");
330 drvdata = kzalloc(sizeof(struct lm3530_data), GFP_KERNEL);
331 if (drvdata == NULL) {
336 drvdata->mode = pdata->mode;
337 drvdata->client = client;
338 drvdata->pdata = pdata;
339 drvdata->brightness = LED_OFF;
340 drvdata->enable = false;
341 drvdata->led_dev.name = LM3530_LED_DEV;
342 drvdata->led_dev.brightness_set = lm3530_brightness_set;
344 i2c_set_clientdata(client, drvdata);
346 drvdata->regulator = regulator_get(&client->dev, "vin");
347 if (IS_ERR(drvdata->regulator)) {
348 dev_err(&client->dev, "regulator get failed\n");
349 err = PTR_ERR(drvdata->regulator);
350 drvdata->regulator = NULL;
351 goto err_regulator_get;
354 if (drvdata->pdata->brt_val) {
355 err = lm3530_init_registers(drvdata);
357 dev_err(&client->dev,
358 "Register Init failed: %d\n", err);
363 err = led_classdev_register(&client->dev, &drvdata->led_dev);
365 dev_err(&client->dev, "Register led class failed: %d\n", err);
367 goto err_class_register;
370 err = device_create_file(drvdata->led_dev.dev, &dev_attr_mode);
372 dev_err(&client->dev, "File device creation failed: %d\n", err);
374 goto err_create_file;
380 led_classdev_unregister(&drvdata->led_dev);
383 regulator_put(drvdata->regulator);
385 i2c_set_clientdata(client, NULL);
391 static int __devexit lm3530_remove(struct i2c_client *client)
393 struct lm3530_data *drvdata = i2c_get_clientdata(client);
395 device_remove_file(drvdata->led_dev.dev, &dev_attr_mode);
398 regulator_disable(drvdata->regulator);
399 regulator_put(drvdata->regulator);
400 led_classdev_unregister(&drvdata->led_dev);
405 static const struct i2c_device_id lm3530_id[] = {
409 MODULE_DEVICE_TABLE(i2c, lm3530_id);
411 static struct i2c_driver lm3530_i2c_driver = {
412 .probe = lm3530_probe,
413 .remove = lm3530_remove,
414 .id_table = lm3530_id,
417 .owner = THIS_MODULE,
421 static int __init lm3530_init(void)
423 return i2c_add_driver(&lm3530_i2c_driver);
426 static void __exit lm3530_exit(void)
428 i2c_del_driver(&lm3530_i2c_driver);
431 module_init(lm3530_init);
432 module_exit(lm3530_exit);
434 MODULE_DESCRIPTION("Back Light driver for LM3530");
435 MODULE_LICENSE("GPL v2");
436 MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");