diff options
| -rw-r--r-- | Documentation/backlight/lp855x-driver.txt | 78 | ||||
| -rw-r--r-- | drivers/video/backlight/Kconfig | 7 | ||||
| -rw-r--r-- | drivers/video/backlight/Makefile | 1 | ||||
| -rw-r--r-- | drivers/video/backlight/lp855x_bl.c | 331 | ||||
| -rw-r--r-- | include/linux/lp855x.h | 131 |
5 files changed, 548 insertions, 0 deletions
diff --git a/Documentation/backlight/lp855x-driver.txt b/Documentation/backlight/lp855x-driver.txt new file mode 100644 index 000000000000..f5e4caafab7d --- /dev/null +++ b/Documentation/backlight/lp855x-driver.txt @@ -0,0 +1,78 @@ +Kernel driver lp855x +==================== + +Backlight driver for LP855x ICs + +Supported chips: + Texas Instruments LP8550, LP8551, LP8552, LP8553 and LP8556 + +Author: Milo(Woogyom) Kim <milo.kim@ti.com> + +Description +----------- + +* Brightness control + +Brightness can be controlled by the pwm input or the i2c command. +The lp855x driver supports both cases. + +* Device attributes + +1) bl_ctl_mode +Backlight control mode. +Value : pwm based or register based + +2) chip_id +The lp855x chip id. +Value : lp8550/lp8551/lp8552/lp8553/lp8556 + +Platform data for lp855x +------------------------ + +For supporting platform specific data, the lp855x platform data can be used. + +* name : Backlight driver name. If it is not defined, default name is set. +* mode : Brightness control mode. PWM or register based. +* device_control : Value of DEVICE CONTROL register. +* initial_brightness : Initial value of backlight brightness. +* pwm_data : Platform specific pwm generation functions. + Only valid when brightness is pwm input mode. + Functions should be implemented by PWM driver. + - pwm_set_intensity() : set duty of PWM + - pwm_get_intensity() : get current duty of PWM +* load_new_rom_data : + 0 : use default configuration data + 1 : update values of eeprom or eprom registers on loading driver +* size_program : Total size of lp855x_rom_data. +* rom_data : List of new eeprom/eprom registers. + +example 1) lp8552 platform data : i2c register mode with new eeprom data + +#define EEPROM_A5_ADDR 0xA5 +#define EEPROM_A5_VAL 0x4f /* EN_VSYNC=0 */ + +static struct lp855x_rom_data lp8552_eeprom_arr[] = { + {EEPROM_A5_ADDR, EEPROM_A5_VAL}, +}; + +static struct lp855x_platform_data lp8552_pdata = { + .name = "lcd-bl", + .mode = REGISTER_BASED, + .device_control = I2C_CONFIG(LP8552), + .initial_brightness = INITIAL_BRT, + .load_new_rom_data = 1, + .size_program = ARRAY_SIZE(lp8552_eeprom_arr), + .rom_data = lp8552_eeprom_arr, +}; + +example 2) lp8556 platform data : pwm input mode with default rom data + +static struct lp855x_platform_data lp8556_pdata = { + .mode = PWM_BASED, + .device_control = PWM_CONFIG(LP8556), + .initial_brightness = INITIAL_BRT, + .pwm_data = { + .pwm_set_intensity = platform_pwm_set_intensity, + .pwm_get_intensity = platform_pwm_get_intensity, + }, +}; diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig index 681b36929fe4..49e7d83f869f 100644 --- a/drivers/video/backlight/Kconfig +++ b/drivers/video/backlight/Kconfig @@ -334,6 +334,13 @@ config BACKLIGHT_AAT2870 If you have a AnalogicTech AAT2870 say Y to enable the backlight driver. +config BACKLIGHT_LP855X + tristate "Backlight driver for TI LP855X" + depends on BACKLIGHT_CLASS_DEVICE && I2C + help + This supports TI LP8550, LP8551, LP8552, LP8553 and LP8556 + backlight driver. + endif # BACKLIGHT_CLASS_DEVICE endif # BACKLIGHT_LCD_SUPPORT diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile index af5cf654ec7c..0ee06e0832bd 100644 --- a/drivers/video/backlight/Makefile +++ b/drivers/video/backlight/Makefile @@ -22,6 +22,7 @@ obj-$(CONFIG_BACKLIGHT_GENERIC) += generic_bl.o obj-$(CONFIG_BACKLIGHT_HP700) += jornada720_bl.o obj-$(CONFIG_BACKLIGHT_HP680) += hp680_bl.o obj-$(CONFIG_BACKLIGHT_LOCOMO) += locomolcd.o +obj-$(CONFIG_BACKLIGHT_LP855X) += lp855x_bl.o obj-$(CONFIG_BACKLIGHT_OMAP1) += omap1_bl.o obj-$(CONFIG_BACKLIGHT_PROGEAR) += progear_bl.o obj-$(CONFIG_BACKLIGHT_CARILLO_RANCH) += cr_bllcd.o diff --git a/drivers/video/backlight/lp855x_bl.c b/drivers/video/backlight/lp855x_bl.c new file mode 100644 index 000000000000..72a0e0c917cf --- /dev/null +++ b/drivers/video/backlight/lp855x_bl.c @@ -0,0 +1,331 @@ +/* + * TI LP855x Backlight Driver + * + * Copyright (C) 2011 Texas Instruments + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/i2c.h> +#include <linux/backlight.h> +#include <linux/err.h> +#include <linux/lp855x.h> + +/* Registers */ +#define BRIGHTNESS_CTRL (0x00) +#define DEVICE_CTRL (0x01) + +#define BUF_SIZE 20 +#define DEFAULT_BL_NAME "lcd-backlight" +#define MAX_BRIGHTNESS 255 + +struct lp855x { + const char *chipname; + enum lp855x_chip_id chip_id; + struct i2c_client *client; + struct backlight_device *bl; + struct device *dev; + struct mutex xfer_lock; + struct lp855x_platform_data *pdata; +}; + +static int lp855x_read_byte(struct lp855x *lp, u8 reg, u8 *data) +{ + int ret; + + mutex_lock(&lp->xfer_lock); + ret = i2c_smbus_read_byte_data(lp->client, reg); + if (ret < 0) { + mutex_unlock(&lp->xfer_lock); + dev_err(lp->dev, "failed to read 0x%.2x\n", reg); + return ret; + } + mutex_unlock(&lp->xfer_lock); + + *data = (u8)ret; + return 0; +} + +static int lp855x_write_byte(struct lp855x *lp, u8 reg, u8 data) +{ + int ret; + + mutex_lock(&lp->xfer_lock); + ret = i2c_smbus_write_byte_data(lp->client, reg, data); + mutex_unlock(&lp->xfer_lock); + + return ret; +} + +static bool lp855x_is_valid_rom_area(struct lp855x *lp, u8 addr) +{ + u8 start, end; + + switch (lp->chip_id) { + case LP8550: + case LP8551: + case LP8552: + case LP8553: + start = EEPROM_START; + end = EEPROM_END; + break; + case LP8556: + start = EPROM_START; + end = EPROM_END; + break; + default: + return false; + } + + return (addr >= start && addr <= end); +} + +static int lp855x_init_registers(struct lp855x *lp) +{ + u8 val, addr; + int i, ret; + struct lp855x_platform_data *pd = lp->pdata; + + val = pd->initial_brightness; + ret = lp855x_write_byte(lp, BRIGHTNESS_CTRL, val); + if (ret) + return ret; + + val = pd->device_control; + ret = lp855x_write_byte(lp, DEVICE_CTRL, val); + if (ret) + return ret; + + if (pd->load_new_rom_data && pd->size_program) { + for (i = 0; i < pd->size_program; i++) { + addr = pd->rom_data[i].addr; + val = pd->rom_data[i].val; + if (!lp855x_is_valid_rom_area(lp, addr)) + continue; + + ret = lp855x_write_byte(lp, addr, val); + if (ret) + return ret; + } + } + + return ret; +} + +static int lp855x_bl_update_status(struct backlight_device *bl) +{ + struct lp855x *lp = bl_get_data(bl); + enum lp855x_brightness_ctrl_mode mode = lp->pdata->mode; + + if (bl->props.state & BL_CORE_SUSPENDED) + bl->props.brightness = 0; + + if (mode == PWM_BASED) { + struct lp855x_pwm_data *pd = &lp->pdata->pwm_data; + int br = bl->props.brightness; + int max_br = bl->props.max_brightness; + + if (pd->pwm_set_intensity) + pd->pwm_set_intensity(br, max_br); + + } else if (mode == REGISTER_BASED) { + u8 val = bl->props.brightness; + lp855x_write_byte(lp, BRIGHTNESS_CTRL, val); + } + + return 0; +} + +static int lp855x_bl_get_brightness(struct backlight_device *bl) +{ + struct lp855x *lp = bl_get_data(bl); + enum lp855x_brightness_ctrl_mode mode = lp->pdata->mode; + + if (mode == PWM_BASED) { + struct lp855x_pwm_data *pd = &lp->pdata->pwm_data; + int max_br = bl->props.max_brightness; + + if (pd->pwm_get_intensity) + bl->props.brightness = pd->pwm_get_intensity(max_br); + + } else if (mode == REGISTER_BASED) { + u8 val = 0; + + lp855x_read_byte(lp, BRIGHTNESS_CTRL, &val); + bl->props.brightness = val; + } + + return bl->props.brightness; +} + +static const struct backlight_ops lp855x_bl_ops = { + .options = BL_CORE_SUSPENDRESUME, + .update_status = lp855x_bl_update_status, + .get_brightness = lp855x_bl_get_brightness, +}; + +static int lp855x_backlight_register(struct lp855x *lp) +{ + struct backlight_device *bl; + struct backlight_properties props; + struct lp855x_platform_data *pdata = lp->pdata; + char *name = pdata->name ? : DEFAULT_BL_NAME; + + props.type = BACKLIGHT_PLATFORM; + props.max_brightness = MAX_BRIGHTNESS; + + if (pdata->initial_brightness > props.max_brightness) + pdata->initial_brightness = props.max_brightness; + + props.brightness = pdata->initial_brightness; + + bl = backlight_device_register(name, lp->dev, lp, + &lp855x_bl_ops, &props); + if (IS_ERR(bl)) + return PTR_ERR(bl); + + lp->bl = bl; + + return 0; +} + +static void lp855x_backlight_unregister(struct lp855x *lp) +{ + if (lp->bl) + backlight_device_unregister(lp->bl); +} + +static ssize_t lp855x_get_chip_id(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct lp855x *lp = dev_get_drvdata(dev); + return scnprintf(buf, BUF_SIZE, "%s\n", lp->chipname); +} + +static ssize_t lp855x_get_bl_ctl_mode(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct lp855x *lp = dev_get_drvdata(dev); + enum lp855x_brightness_ctrl_mode mode = lp->pdata->mode; + char *strmode = NULL; + + if (mode == PWM_BASED) + strmode = "pwm based"; + else if (mode == REGISTER_BASED) + strmode = "register based"; + + return scnprintf(buf, BUF_SIZE, "%s\n", strmode); +} + +static DEVICE_ATTR(chip_id, S_IRUGO, lp855x_get_chip_id, NULL); +static DEVICE_ATTR(bl_ctl_mode, S_IRUGO, lp855x_get_bl_ctl_mode, NULL); + +static struct attribute *lp855x_attributes[] = { + &dev_attr_chip_id.attr, + &dev_attr_bl_ctl_mode.attr, + NULL, +}; + +static const struct attribute_group lp855x_attr_group = { + .attrs = lp855x_attributes, +}; + +static int lp855x_probe(struct i2c_client *cl, const struct i2c_device_id *id) +{ + struct lp855x *lp; + struct lp855x_platform_data *pdata = cl->dev.platform_data; + enum lp855x_brightness_ctrl_mode mode; + int ret; + + if (!pdata) { + dev_err(&cl->dev, "no platform data supplied\n"); + return -EINVAL; + } + + if (!i2c_check_functionality(cl->adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) + return -EIO; + + lp = devm_kzalloc(&cl->dev, sizeof(struct lp855x), GFP_KERNEL); + if (!lp) + return -ENOMEM; + + mode = pdata->mode; + lp->client = cl; + lp->dev = &cl->dev; + lp->pdata = pdata; + lp->chipname = id->name; + lp->chip_id = id->driver_data; + i2c_set_clientdata(cl, lp); + + mutex_init(&lp->xfer_lock); + + ret = lp855x_init_registers(lp); + if (ret) { + dev_err(lp->dev, "i2c communication err: %d", ret); + if (mode == REGISTER_BASED) + goto err_dev; + } + + ret = lp855x_backlight_register(lp); + if (ret) { + dev_err(lp->dev, + "failed to register backlight. err: %d\n", ret); + goto err_dev; + } + + ret = sysfs_create_group(&lp->dev->kobj, &lp855x_attr_group); + if (ret) { + dev_err(lp->dev, "failed to register sysfs. err: %d\n", ret); + goto err_sysfs; + } + + backlight_update_status(lp->bl); + return 0; + +err_sysfs: + lp855x_backlight_unregister(lp); +err_dev: + return ret; +} + +static int __devexit lp855x_remove(struct i2c_client *cl) +{ + struct lp855x *lp = i2c_get_clientdata(cl); + + lp->bl->props.brightness = 0; + backlight_update_status(lp->bl); + sysfs_remove_group(&lp->dev->kobj, &lp855x_attr_group); + lp855x_backlight_unregister(lp); + + return 0; +} + +static const struct i2c_device_id lp855x_ids[] = { + {"lp8550", LP8550}, + {"lp8551", LP8551}, + {"lp8552", LP8552}, + {"lp8553", LP8553}, + {"lp8556", LP8556}, + { } +}; +MODULE_DEVICE_TABLE(i2c, lp855x_ids); + +static struct i2c_driver lp855x_driver = { + .driver = { + .name = "lp855x", + }, + .probe = lp855x_probe, + .remove = __devexit_p(lp855x_remove), + .id_table = lp855x_ids, +}; + +module_i2c_driver(lp855x_driver); + +MODULE_DESCRIPTION("Texas Instruments LP855x Backlight driver"); +MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/lp855x.h b/include/linux/lp855x.h new file mode 100644 index 000000000000..781a490a451b --- /dev/null +++ b/include/linux/lp855x.h @@ -0,0 +1,131 @@ +/* + * LP855x Backlight Driver + * + * Copyright (C) 2011 Texas Instruments + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#ifndef _LP855X_H +#define _LP855X_H + +#define BL_CTL_SHFT (0) +#define BRT_MODE_SHFT (1) +#define BRT_MODE_MASK (0x06) + +/* Enable backlight. Only valid when BRT_MODE=10(I2C only) */ +#define ENABLE_BL (1) +#define DISABLE_BL (0) + +#define I2C_CONFIG(id) id ## _I2C_CONFIG +#define PWM_CONFIG(id) id ## _PWM_CONFIG + +/* DEVICE CONTROL register - LP8550 */ +#define LP8550_PWM_CONFIG (LP8550_PWM_ONLY << BRT_MODE_SHFT) +#define LP8550_I2C_CONFIG ((ENABLE_BL << BL_CTL_SHFT) | \ + (LP8550_I2C_ONLY << BRT_MODE_SHFT)) + +/* DEVICE CONTROL register - LP8551 */ +#define LP8551_PWM_CONFIG LP8550_PWM_CONFIG +#define LP8551_I2C_CONFIG LP8550_I2C_CONFIG + +/* DEVICE CONTROL register - LP8552 */ +#define LP8552_PWM_CONFIG LP8550_PWM_CONFIG +#define LP8552_I2C_CONFIG LP8550_I2C_CONFIG + +/* DEVICE CONTROL register - LP8553 */ +#define LP8553_PWM_CONFIG LP8550_PWM_CONFIG +#define LP8553_I2C_CONFIG LP8550_I2C_CONFIG + +/* DEVICE CONTROL register - LP8556 */ +#define LP8556_PWM_CONFIG (LP8556_PWM_ONLY << BRT_MODE_SHFT) +#define LP8556_COMB1_CONFIG (LP8556_COMBINED1 << BRT_MODE_SHFT) +#define LP8556_I2C_CONFIG ((ENABLE_BL << BL_CTL_SHFT) | \ + (LP8556_I2C_ONLY << BRT_MODE_SHFT)) +#define LP8556_COMB2_CONFIG (LP8556_COMBINED2 << BRT_MODE_SHFT) + +/* ROM area boundary */ +#define EEPROM_START (0xA0) +#define EEPROM_END (0xA7) +#define EPROM_START (0xA0) +#define EPROM_END (0xAF) + +enum lp855x_chip_id { + LP8550, + LP8551, + LP8552, + LP8553, + LP8556, +}; + +enum lp855x_brightness_ctrl_mode { + PWM_BASED = 1, + REGISTER_BASED, +}; + +enum lp8550_brighntess_source { + LP8550_PWM_ONLY, + LP8550_I2C_ONLY = 2, +}; + +enum lp8551_brighntess_source { + LP8551_PWM_ONLY = LP8550_PWM_ONLY, + LP8551_I2C_ONLY = LP8550_I2C_ONLY, +}; + +enum lp8552_brighntess_source { + LP8552_PWM_ONLY = LP8550_PWM_ONLY, + LP8552_I2C_ONLY = LP8550_I2C_ONLY, +}; + +enum lp8553_brighntess_source { + LP8553_PWM_ONLY = LP8550_PWM_ONLY, + LP8553_I2C_ONLY = LP8550_I2C_ONLY, +}; + +enum lp8556_brightness_source { + LP8556_PWM_ONLY, + LP8556_COMBINED1, /* pwm + i2c before the shaper block */ + LP8556_I2C_ONLY, + LP8556_COMBINED2, /* pwm + i2c after the shaper block */ +}; + +struct lp855x_pwm_data { + void (*pwm_set_intensity) (int brightness, int max_brightness); + int (*pwm_get_intensity) (int max_brightness); +}; + +struct lp855x_rom_data { + u8 addr; + u8 val; +}; + +/** + * struct lp855x_platform_data + * @name : Backlight driver name. If it is not defined, default name is set. + * @mode : brightness control by pwm or lp855x register + * @device_control : value of DEVICE CONTROL register + * @initial_brightness : initial value of backlight brightness + * @pwm_data : platform specific pwm generation functions. + Only valid when mode is PWM_BASED. + * @load_new_rom_data : + 0 : use default configuration data + 1 : update values of eeprom or eprom registers on loading driver + * @size_program : total size of lp855x_rom_data + * @rom_data : list of new eeprom/eprom registers + */ +struct lp855x_platform_data { + char *name; + enum lp855x_brightness_ctrl_mode mode; + u8 device_control; + int initial_brightness; + struct lp855x_pwm_data pwm_data; + u8 load_new_rom_data; + int size_program; + struct lp855x_rom_data *rom_data; +}; + +#endif |