/* * 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_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 14 /* 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) /* 7 bits are used for the brightness : LM3530_BRT_CTRL_REG */ #define MAX_BRIGHTNESS (127) 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; }; /* * struct lm3530_als_data * @config : value of ALS configuration register * @imp_sel : value of ALS resistor select register * @zone : values of ALS ZB(Zone Boundary) registers */ struct lm3530_als_data { u8 config; u8 imp_sel; u8 zones[LM3530_ALS_ZB_MAX]; }; static const u8 lm3530_reg[LM3530_REG_MAX] = { LM3530_GEN_CONFIG, LM3530_ALS_CONFIG, LM3530_BRT_RAMP_RATE, 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 -EINVAL; } static void lm3530_als_configure(struct lm3530_platform_data *pdata, struct lm3530_als_data *als) { int i; u32 als_vmin, als_vmax, als_vstep; if (pdata->als_vmax == 0) { pdata->als_vmin = 0; pdata->als_vmax = LM3530_ALS_WINDOW_mV; } als_vmin = pdata->als_vmin; als_vmax = pdata->als_vmax; if ((als_vmax - als_vmin) > LM3530_ALS_WINDOW_mV) pdata->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++) als->zones[i] = (((als_vmin + LM3530_ALS_OFFSET_mV) + als_vstep + (i * als_vstep)) * LED_FULL) / 1000; als->config = (pdata->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) | (LM3530_ENABLE_ALS) | (pdata->als_input_mode << LM3530_ALS_SEL_SHIFT); als->imp_sel = (pdata->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) | (pdata->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT); } static int lm3530_led_enable(struct lm3530_data *drvdata) { int ret; if (drvdata->enable) return 0; ret = regulator_enable(drvdata->regulator); if (ret) { dev_err(drvdata->led_dev.dev, "Failed to enable vin:%d\n", ret); return ret; } drvdata->enable = true; return 0; } static void lm3530_led_disable(struct lm3530_data *drvdata) { int ret; if (!drvdata->enable) return; ret = regulator_disable(drvdata->regulator); if (ret) { dev_err(drvdata->led_dev.dev, "Failed to disable vin:%d\n", ret); return; } drvdata->enable = false; } static int lm3530_init_registers(struct lm3530_data *drvdata) { int ret = 0; int i; u8 gen_config; u8 brt_ramp; u8 brightness; u8 reg_val[LM3530_REG_MAX]; struct lm3530_platform_data *pdata = drvdata->pdata; struct i2c_client *client = drvdata->client; struct lm3530_pwm_data *pwm = &pdata->pwm_data; struct lm3530_als_data als; memset(&als, 0, sizeof(struct lm3530_als_data)); gen_config = (pdata->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) | ((pdata->max_current & 7) << LM3530_MAX_CURR_SHIFT); switch (drvdata->mode) { case LM3530_BL_MODE_MANUAL: gen_config |= LM3530_ENABLE_I2C; break; case LM3530_BL_MODE_ALS: gen_config |= LM3530_ENABLE_I2C; lm3530_als_configure(pdata, &als); break; case LM3530_BL_MODE_PWM: gen_config |= LM3530_ENABLE_PWM | LM3530_ENABLE_PWM_SIMPLE | (pdata->pwm_pol_hi << LM3530_PWM_POL_SHIFT); break; } brt_ramp = (pdata->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) | (pdata->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT); if (drvdata->brightness) brightness = drvdata->brightness; else brightness = drvdata->brightness = pdata->brt_val; if (brightness > drvdata->led_dev.max_brightness) brightness = drvdata->led_dev.max_brightness; 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] = als.imp_sel; /* LM3530_ALS_IMP_SELECT */ reg_val[4] = brightness; /* LM3530_BRT_CTRL_REG */ reg_val[5] = als.zones[0]; /* LM3530_ALS_ZB0_REG */ reg_val[6] = als.zones[1]; /* LM3530_ALS_ZB1_REG */ reg_val[7] = als.zones[2]; /* LM3530_ALS_ZB2_REG */ reg_val[8] = als.zones[3]; /* LM3530_ALS_ZB3_REG */ reg_val[9] = LM3530_DEF_ZT_0; /* LM3530_ALS_Z0T_REG */ reg_val[10] = LM3530_DEF_ZT_1; /* LM3530_ALS_Z1T_REG */ reg_val[11] = LM3530_DEF_ZT_2; /* LM3530_ALS_Z2T_REG */ reg_val[12] = LM3530_DEF_ZT_3; /* LM3530_ALS_Z3T_REG */ reg_val[13] = LM3530_DEF_ZT_4; /* LM3530_ALS_Z4T_REG */ ret = lm3530_led_enable(drvdata); if (ret) return ret; for (i = 0; i < LM3530_REG_MAX; i++) { /* do not update brightness register when pwm mode */ if (lm3530_reg[i] == LM3530_BRT_CTRL_REG && drvdata->mode == LM3530_BL_MODE_PWM) { if (pwm->pwm_set_intensity) pwm->pwm_set_intensity(reg_val[i], drvdata->led_dev.max_brightness); continue; } 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); struct lm3530_platform_data *pdata = drvdata->pdata; struct lm3530_pwm_data *pwm = &pdata->pwm_data; u8 max_brightness = led_cdev->max_brightness; 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); if (err) dev_err(&drvdata->client->dev, "Unable to set brightness: %d\n", err); else drvdata->brightness = brt_val; if (brt_val == 0) lm3530_led_disable(drvdata); break; case LM3530_BL_MODE_ALS: break; case LM3530_BL_MODE_PWM: if (pwm->pwm_set_intensity) pwm->pwm_set_intensity(brt_val, max_brightness); break; default: break; } } static ssize_t lm3530_mode_get(struct device *dev, struct device_attribute *attr, char *buf) { struct led_classdev *led_cdev = dev_get_drvdata(dev); struct lm3530_data *drvdata; int i, len = 0; drvdata = container_of(led_cdev, struct lm3530_data, led_dev); 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) { struct led_classdev *led_cdev = dev_get_drvdata(dev); struct lm3530_data *drvdata; struct lm3530_pwm_data *pwm; u8 max_brightness; int mode, err; drvdata = container_of(led_cdev, struct lm3530_data, led_dev); pwm = &drvdata->pdata->pwm_data; max_brightness = led_cdev->max_brightness; mode = lm3530_get_mode_from_str(buf); if (mode < 0) { dev_err(dev, "Invalid mode\n"); return mode; } drvdata->mode = mode; /* set pwm to low if unnecessary */ if (mode != LM3530_BL_MODE_PWM && pwm->pwm_set_intensity) pwm->pwm_set_intensity(0, max_brightness); 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 struct attribute *lm3530_attrs[] = { &dev_attr_mode.attr, NULL }; ATTRIBUTE_GROUPS(lm3530); static int lm3530_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct lm3530_platform_data *pdata = dev_get_platdata(&client->dev); struct lm3530_data *drvdata; int err = 0; if (pdata == NULL) { dev_err(&client->dev, "platform data required\n"); return -ENODEV; } /* BL mode */ if (pdata->mode > LM3530_BL_MODE_PWM) { dev_err(&client->dev, "Illegal Mode request\n"); return -EINVAL; } if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { dev_err(&client->dev, "I2C_FUNC_I2C not supported\n"); return -EIO; } drvdata = devm_kzalloc(&client->dev, sizeof(struct lm3530_data), GFP_KERNEL); if (drvdata == NULL) return -ENOMEM; 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; drvdata->led_dev.max_brightness = MAX_BRIGHTNESS; drvdata->led_dev.groups = lm3530_groups; i2c_set_clientdata(client, drvdata); drvdata->regulator = devm_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; return err; } if (drvdata->pdata->brt_val) { err = lm3530_init_registers(drvdata); if (err < 0) { dev_err(&client->dev, "Register Init failed: %d\n", err); return err; } } err = led_classdev_register(&client->dev, &drvdata->led_dev); if (err < 0) { dev_err(&client->dev, "Register led class failed: %d\n", err); return err; } return 0; } static int lm3530_remove(struct i2c_client *client) { struct lm3530_data *drvdata = i2c_get_clientdata(client); lm3530_led_disable(drvdata); led_classdev_unregister(&drvdata->led_dev); 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 = lm3530_remove, .id_table = lm3530_id, .driver = { .name = LM3530_NAME, }, }; module_i2c_driver(lm3530_i2c_driver); MODULE_DESCRIPTION("Back Light driver for LM3530"); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");