| /* |
| * Copyright (C) 2011 ST-Ericsson SA. |
| * Copyright (C) 2009 Motorola, Inc. |
| * |
| * License Terms: GNU General Public License v2 |
| * |
| * Simple driver for National Semiconductor LM3530 Backlight driver chip |
| * |
| * Author: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com> |
| * based on leds-lm3530.c by Dan Murphy <D.Murphy@motorola.com> |
| */ |
| |
| #include <linux/i2c.h> |
| #include <linux/leds.h> |
| #include <linux/slab.h> |
| #include <linux/platform_device.h> |
| #include <linux/input.h> |
| #include <linux/led-lm3530.h> |
| #include <linux/types.h> |
| #include <linux/regulator/consumer.h> |
| #include <linux/module.h> |
| |
| #define LM3530_LED_DEV "lcd-backlight" |
| #define LM3530_NAME "lm3530-led" |
| |
| #define LM3530_GEN_CONFIG 0x10 |
| #define LM3530_ALS_CONFIG 0x20 |
| #define LM3530_BRT_RAMP_RATE 0x30 |
| #define LM3530_ALS_ZONE_REG 0x40 |
| #define LM3530_ALS_IMP_SELECT 0x41 |
| #define LM3530_BRT_CTRL_REG 0xA0 |
| #define LM3530_ALS_ZB0_REG 0x60 |
| #define LM3530_ALS_ZB1_REG 0x61 |
| #define LM3530_ALS_ZB2_REG 0x62 |
| #define LM3530_ALS_ZB3_REG 0x63 |
| #define LM3530_ALS_Z0T_REG 0x70 |
| #define LM3530_ALS_Z1T_REG 0x71 |
| #define LM3530_ALS_Z2T_REG 0x72 |
| #define LM3530_ALS_Z3T_REG 0x73 |
| #define LM3530_ALS_Z4T_REG 0x74 |
| #define LM3530_REG_MAX 15 |
| |
| /* General Control Register */ |
| #define LM3530_EN_I2C_SHIFT (0) |
| #define LM3530_RAMP_LAW_SHIFT (1) |
| #define LM3530_MAX_CURR_SHIFT (2) |
| #define LM3530_EN_PWM_SHIFT (5) |
| #define LM3530_PWM_POL_SHIFT (6) |
| #define LM3530_EN_PWM_SIMPLE_SHIFT (7) |
| |
| #define LM3530_ENABLE_I2C (1 << LM3530_EN_I2C_SHIFT) |
| #define LM3530_ENABLE_PWM (1 << LM3530_EN_PWM_SHIFT) |
| #define LM3530_POL_LOW (1 << LM3530_PWM_POL_SHIFT) |
| #define LM3530_ENABLE_PWM_SIMPLE (1 << LM3530_EN_PWM_SIMPLE_SHIFT) |
| |
| /* ALS Config Register Options */ |
| #define LM3530_ALS_AVG_TIME_SHIFT (0) |
| #define LM3530_EN_ALS_SHIFT (3) |
| #define LM3530_ALS_SEL_SHIFT (5) |
| |
| #define LM3530_ENABLE_ALS (3 << LM3530_EN_ALS_SHIFT) |
| |
| /* Brightness Ramp Rate Register */ |
| #define LM3530_BRT_RAMP_FALL_SHIFT (0) |
| #define LM3530_BRT_RAMP_RISE_SHIFT (3) |
| |
| /* ALS Resistor Select */ |
| #define LM3530_ALS1_IMP_SHIFT (0) |
| #define LM3530_ALS2_IMP_SHIFT (4) |
| |
| /* Zone Boundary Register defaults */ |
| #define LM3530_ALS_ZB_MAX (4) |
| #define LM3530_ALS_WINDOW_mV (1000) |
| #define LM3530_ALS_OFFSET_mV (4) |
| |
| /* Zone Target Register defaults */ |
| #define LM3530_DEF_ZT_0 (0x7F) |
| #define LM3530_DEF_ZT_1 (0x66) |
| #define LM3530_DEF_ZT_2 (0x4C) |
| #define LM3530_DEF_ZT_3 (0x33) |
| #define LM3530_DEF_ZT_4 (0x19) |
| |
| struct lm3530_mode_map { |
| const char *mode; |
| enum lm3530_mode mode_val; |
| }; |
| |
| static struct lm3530_mode_map mode_map[] = { |
| { "man", LM3530_BL_MODE_MANUAL }, |
| { "als", LM3530_BL_MODE_ALS }, |
| { "pwm", LM3530_BL_MODE_PWM }, |
| }; |
| |
| /** |
| * struct lm3530_data |
| * @led_dev: led class device |
| * @client: i2c client |
| * @pdata: LM3530 platform data |
| * @mode: mode of operation - manual, ALS, PWM |
| * @regulator: regulator |
| * @brighness: previous brightness value |
| * @enable: regulator is enabled |
| */ |
| struct lm3530_data { |
| struct led_classdev led_dev; |
| struct i2c_client *client; |
| struct lm3530_platform_data *pdata; |
| enum lm3530_mode mode; |
| struct regulator *regulator; |
| enum led_brightness brightness; |
| bool enable; |
| }; |
| |
| static const u8 lm3530_reg[LM3530_REG_MAX] = { |
| LM3530_GEN_CONFIG, |
| LM3530_ALS_CONFIG, |
| LM3530_BRT_RAMP_RATE, |
| LM3530_ALS_ZONE_REG, |
| LM3530_ALS_IMP_SELECT, |
| LM3530_BRT_CTRL_REG, |
| LM3530_ALS_ZB0_REG, |
| LM3530_ALS_ZB1_REG, |
| LM3530_ALS_ZB2_REG, |
| LM3530_ALS_ZB3_REG, |
| LM3530_ALS_Z0T_REG, |
| LM3530_ALS_Z1T_REG, |
| LM3530_ALS_Z2T_REG, |
| LM3530_ALS_Z3T_REG, |
| LM3530_ALS_Z4T_REG, |
| }; |
| |
| static int lm3530_get_mode_from_str(const char *str) |
| { |
| int i; |
| |
| for (i = 0; i < ARRAY_SIZE(mode_map); i++) |
| if (sysfs_streq(str, mode_map[i].mode)) |
| return mode_map[i].mode_val; |
| |
| return -1; |
| } |
| |
| static int lm3530_init_registers(struct lm3530_data *drvdata) |
| { |
| int ret = 0; |
| int i; |
| u8 gen_config; |
| u8 als_config = 0; |
| u8 brt_ramp; |
| u8 als_imp_sel = 0; |
| u8 brightness; |
| u8 reg_val[LM3530_REG_MAX]; |
| u8 zones[LM3530_ALS_ZB_MAX]; |
| u32 als_vmin, als_vmax, als_vstep; |
| struct lm3530_platform_data *pltfm = drvdata->pdata; |
| struct i2c_client *client = drvdata->client; |
| |
| gen_config = (pltfm->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) | |
| ((pltfm->max_current & 7) << LM3530_MAX_CURR_SHIFT); |
| |
| if (drvdata->mode == LM3530_BL_MODE_MANUAL || |
| drvdata->mode == LM3530_BL_MODE_ALS) |
| gen_config |= (LM3530_ENABLE_I2C); |
| |
| if (drvdata->mode == LM3530_BL_MODE_ALS) { |
| if (pltfm->als_vmax == 0) { |
| pltfm->als_vmin = als_vmin = 0; |
| pltfm->als_vmin = als_vmax = LM3530_ALS_WINDOW_mV; |
| } |
| |
| als_vmin = pltfm->als_vmin; |
| als_vmax = pltfm->als_vmax; |
| |
| if ((als_vmax - als_vmin) > LM3530_ALS_WINDOW_mV) |
| pltfm->als_vmax = als_vmax = |
| als_vmin + LM3530_ALS_WINDOW_mV; |
| |
| /* n zone boundary makes n+1 zones */ |
| als_vstep = (als_vmax - als_vmin) / (LM3530_ALS_ZB_MAX + 1); |
| |
| for (i = 0; i < LM3530_ALS_ZB_MAX; i++) |
| zones[i] = (((als_vmin + LM3530_ALS_OFFSET_mV) + |
| als_vstep + (i * als_vstep)) * LED_FULL) |
| / 1000; |
| |
| als_config = |
| (pltfm->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) | |
| (LM3530_ENABLE_ALS) | |
| (pltfm->als_input_mode << LM3530_ALS_SEL_SHIFT); |
| |
| als_imp_sel = |
| (pltfm->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) | |
| (pltfm->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT); |
| |
| } |
| |
| if (drvdata->mode == LM3530_BL_MODE_PWM) |
| gen_config |= (LM3530_ENABLE_PWM) | |
| (pltfm->pwm_pol_hi << LM3530_PWM_POL_SHIFT) | |
| (LM3530_ENABLE_PWM_SIMPLE); |
| |
| brt_ramp = (pltfm->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) | |
| (pltfm->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT); |
| |
| if (drvdata->brightness) |
| brightness = drvdata->brightness; |
| else |
| brightness = drvdata->brightness = pltfm->brt_val; |
| |
| reg_val[0] = gen_config; /* LM3530_GEN_CONFIG */ |
| reg_val[1] = als_config; /* LM3530_ALS_CONFIG */ |
| reg_val[2] = brt_ramp; /* LM3530_BRT_RAMP_RATE */ |
| reg_val[3] = 0x00; /* LM3530_ALS_ZONE_REG */ |
| reg_val[4] = als_imp_sel; /* LM3530_ALS_IMP_SELECT */ |
| reg_val[5] = brightness; /* LM3530_BRT_CTRL_REG */ |
| reg_val[6] = zones[0]; /* LM3530_ALS_ZB0_REG */ |
| reg_val[7] = zones[1]; /* LM3530_ALS_ZB1_REG */ |
| reg_val[8] = zones[2]; /* LM3530_ALS_ZB2_REG */ |
| reg_val[9] = zones[3]; /* LM3530_ALS_ZB3_REG */ |
| reg_val[10] = LM3530_DEF_ZT_0; /* LM3530_ALS_Z0T_REG */ |
| reg_val[11] = LM3530_DEF_ZT_1; /* LM3530_ALS_Z1T_REG */ |
| reg_val[12] = LM3530_DEF_ZT_2; /* LM3530_ALS_Z2T_REG */ |
| reg_val[13] = LM3530_DEF_ZT_3; /* LM3530_ALS_Z3T_REG */ |
| reg_val[14] = LM3530_DEF_ZT_4; /* LM3530_ALS_Z4T_REG */ |
| |
| if (!drvdata->enable) { |
| ret = regulator_enable(drvdata->regulator); |
| if (ret) { |
| dev_err(&drvdata->client->dev, |
| "Enable regulator failed\n"); |
| return ret; |
| } |
| drvdata->enable = true; |
| } |
| |
| for (i = 0; i < LM3530_REG_MAX; i++) { |
| ret = i2c_smbus_write_byte_data(client, |
| lm3530_reg[i], reg_val[i]); |
| if (ret) |
| break; |
| } |
| |
| return ret; |
| } |
| |
| static void lm3530_brightness_set(struct led_classdev *led_cdev, |
| enum led_brightness brt_val) |
| { |
| int err; |
| struct lm3530_data *drvdata = |
| container_of(led_cdev, struct lm3530_data, led_dev); |
| |
| switch (drvdata->mode) { |
| case LM3530_BL_MODE_MANUAL: |
| |
| if (!drvdata->enable) { |
| err = lm3530_init_registers(drvdata); |
| if (err) { |
| dev_err(&drvdata->client->dev, |
| "Register Init failed: %d\n", err); |
| break; |
| } |
| } |
| |
| /* set the brightness in brightness control register*/ |
| err = i2c_smbus_write_byte_data(drvdata->client, |
| LM3530_BRT_CTRL_REG, brt_val / 2); |
| if (err) |
| dev_err(&drvdata->client->dev, |
| "Unable to set brightness: %d\n", err); |
| else |
| drvdata->brightness = brt_val / 2; |
| |
| if (brt_val == 0) { |
| err = regulator_disable(drvdata->regulator); |
| if (err) |
| dev_err(&drvdata->client->dev, |
| "Disable regulator failed\n"); |
| drvdata->enable = false; |
| } |
| break; |
| case LM3530_BL_MODE_ALS: |
| break; |
| case LM3530_BL_MODE_PWM: |
| break; |
| default: |
| break; |
| } |
| } |
| |
| static ssize_t lm3530_mode_get(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct i2c_client *client = container_of( |
| dev->parent, struct i2c_client, dev); |
| struct lm3530_data *drvdata = i2c_get_clientdata(client); |
| int i, len = 0; |
| |
| for (i = 0; i < ARRAY_SIZE(mode_map); i++) |
| if (drvdata->mode == mode_map[i].mode_val) |
| len += sprintf(buf + len, "[%s] ", mode_map[i].mode); |
| else |
| len += sprintf(buf + len, "%s ", mode_map[i].mode); |
| |
| len += sprintf(buf + len, "\n"); |
| |
| return len; |
| } |
| |
| static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute |
| *attr, const char *buf, size_t size) |
| { |
| int err; |
| struct i2c_client *client = container_of( |
| dev->parent, struct i2c_client, dev); |
| struct lm3530_data *drvdata = i2c_get_clientdata(client); |
| int mode; |
| |
| mode = lm3530_get_mode_from_str(buf); |
| if (mode < 0) { |
| dev_err(dev, "Invalid mode\n"); |
| return -EINVAL; |
| } |
| |
| if (mode == LM3530_BL_MODE_MANUAL) |
| drvdata->mode = LM3530_BL_MODE_MANUAL; |
| else if (mode == LM3530_BL_MODE_ALS) |
| drvdata->mode = LM3530_BL_MODE_ALS; |
| else if (mode == LM3530_BL_MODE_PWM) { |
| dev_err(dev, "PWM mode not supported\n"); |
| return -EINVAL; |
| } |
| |
| err = lm3530_init_registers(drvdata); |
| if (err) { |
| dev_err(dev, "Setting %s Mode failed :%d\n", buf, err); |
| return err; |
| } |
| |
| return sizeof(drvdata->mode); |
| } |
| static DEVICE_ATTR(mode, 0644, lm3530_mode_get, lm3530_mode_set); |
| |
| static int __devinit lm3530_probe(struct i2c_client *client, |
| const struct i2c_device_id *id) |
| { |
| struct lm3530_platform_data *pdata = client->dev.platform_data; |
| struct lm3530_data *drvdata; |
| int err = 0; |
| |
| if (pdata == NULL) { |
| dev_err(&client->dev, "platform data required\n"); |
| err = -ENODEV; |
| goto err_out; |
| } |
| |
| /* BL mode */ |
| if (pdata->mode > LM3530_BL_MODE_PWM) { |
| dev_err(&client->dev, "Illegal Mode request\n"); |
| err = -EINVAL; |
| goto err_out; |
| } |
| |
| if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { |
| dev_err(&client->dev, "I2C_FUNC_I2C not supported\n"); |
| err = -EIO; |
| goto err_out; |
| } |
| |
| drvdata = kzalloc(sizeof(struct lm3530_data), GFP_KERNEL); |
| if (drvdata == NULL) { |
| err = -ENOMEM; |
| goto err_out; |
| } |
| |
| drvdata->mode = pdata->mode; |
| drvdata->client = client; |
| drvdata->pdata = pdata; |
| drvdata->brightness = LED_OFF; |
| drvdata->enable = false; |
| drvdata->led_dev.name = LM3530_LED_DEV; |
| drvdata->led_dev.brightness_set = lm3530_brightness_set; |
| |
| i2c_set_clientdata(client, drvdata); |
| |
| drvdata->regulator = regulator_get(&client->dev, "vin"); |
| if (IS_ERR(drvdata->regulator)) { |
| dev_err(&client->dev, "regulator get failed\n"); |
| err = PTR_ERR(drvdata->regulator); |
| drvdata->regulator = NULL; |
| goto err_regulator_get; |
| } |
| |
| if (drvdata->pdata->brt_val) { |
| err = lm3530_init_registers(drvdata); |
| if (err < 0) { |
| dev_err(&client->dev, |
| "Register Init failed: %d\n", err); |
| err = -ENODEV; |
| goto err_reg_init; |
| } |
| } |
| err = led_classdev_register(&client->dev, &drvdata->led_dev); |
| if (err < 0) { |
| dev_err(&client->dev, "Register led class failed: %d\n", err); |
| err = -ENODEV; |
| goto err_class_register; |
| } |
| |
| err = device_create_file(drvdata->led_dev.dev, &dev_attr_mode); |
| if (err < 0) { |
| dev_err(&client->dev, "File device creation failed: %d\n", err); |
| err = -ENODEV; |
| goto err_create_file; |
| } |
| |
| return 0; |
| |
| err_create_file: |
| led_classdev_unregister(&drvdata->led_dev); |
| err_class_register: |
| err_reg_init: |
| regulator_put(drvdata->regulator); |
| err_regulator_get: |
| kfree(drvdata); |
| err_out: |
| return err; |
| } |
| |
| static int __devexit lm3530_remove(struct i2c_client *client) |
| { |
| struct lm3530_data *drvdata = i2c_get_clientdata(client); |
| |
| device_remove_file(drvdata->led_dev.dev, &dev_attr_mode); |
| |
| if (drvdata->enable) |
| regulator_disable(drvdata->regulator); |
| regulator_put(drvdata->regulator); |
| led_classdev_unregister(&drvdata->led_dev); |
| kfree(drvdata); |
| return 0; |
| } |
| |
| static const struct i2c_device_id lm3530_id[] = { |
| {LM3530_NAME, 0}, |
| {} |
| }; |
| MODULE_DEVICE_TABLE(i2c, lm3530_id); |
| |
| static struct i2c_driver lm3530_i2c_driver = { |
| .probe = lm3530_probe, |
| .remove = __devexit_p(lm3530_remove), |
| .id_table = lm3530_id, |
| .driver = { |
| .name = LM3530_NAME, |
| .owner = THIS_MODULE, |
| }, |
| }; |
| |
| static int __init lm3530_init(void) |
| { |
| return i2c_add_driver(&lm3530_i2c_driver); |
| } |
| |
| static void __exit lm3530_exit(void) |
| { |
| i2c_del_driver(&lm3530_i2c_driver); |
| } |
| |
| module_init(lm3530_init); |
| module_exit(lm3530_exit); |
| |
| MODULE_DESCRIPTION("Back Light driver for LM3530"); |
| MODULE_LICENSE("GPL v2"); |
| MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>"); |