diff options
Diffstat (limited to 'drivers/leds/leds-lm3530.c')
| -rw-r--r-- | drivers/leds/leds-lm3530.c | 500 |
1 files changed, 500 insertions, 0 deletions
diff --git a/drivers/leds/leds-lm3530.c b/drivers/leds/leds-lm3530.c new file mode 100644 index 000000000..ba906c253 --- /dev/null +++ b/drivers/leds/leds-lm3530.c @@ -0,0 +1,500 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2011 ST-Ericsson SA. + * Copyright (C) 2009 Motorola, Inc. + * + * 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 + * @brightness: 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 mode_show(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 mode_store(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_RW(mode); + +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 void lm3530_remove(struct i2c_client *client) +{ + struct lm3530_data *drvdata = i2c_get_clientdata(client); + + lm3530_led_disable(drvdata); + led_classdev_unregister(&drvdata->led_dev); +} + +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>"); |