Add support for National Semiconductor/TI LP8550/1/2/3/5/6/7 LED Backlight. Driver is based on Linux version but is reworked and optimised for U-Boot DM framework. Currently only register driven backlight control is supported, PWM driver backlight control may be added later if needed.
Signed-off-by: Svyatoslav Ryhel clamor95@gmail.com --- drivers/video/Kconfig | 10 + drivers/video/Makefile | 1 + drivers/video/lp855x_backlight.c | 302 +++++++++++++++++++++++++++++++ 3 files changed, 313 insertions(+) create mode 100644 drivers/video/lp855x_backlight.c
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig index 3c3cebaacd0..926dafe7a5a 100644 --- a/drivers/video/Kconfig +++ b/drivers/video/Kconfig @@ -743,6 +743,16 @@ config BACKLIGHT_LM3533 LM3533 Lighting Power chip. Only Bank A is supported as for now. Supported backlight level range is from 2 to 255 with step of 1.
+config BACKLIGHT_LP855x + bool "Backlight Driver for LP855x" + depends on BACKLIGHT + select DM_I2C + help + Say Y to enable the backlight driver for National Semiconductor / TI + LP8550/1/2/3/5/6/7 LED Backlight Driver. Only register driven mode is + supported for now, PWM mode can be added if there will be any need in + it. Supported backlight level range is from 0 to 255 with step of 1. + source "drivers/video/ti/Kconfig"
source "drivers/video/exynos/Kconfig" diff --git a/drivers/video/Makefile b/drivers/video/Makefile index 5a00438ce06..391ef8397bc 100644 --- a/drivers/video/Makefile +++ b/drivers/video/Makefile @@ -30,6 +30,7 @@ obj-$(CONFIG_$(PHASE_)BMP) += bmp.o endif
obj-$(CONFIG_BACKLIGHT_LM3533) += lm3533_backlight.o +obj-$(CONFIG_BACKLIGHT_LP855x) += lp855x_backlight.o obj-${CONFIG_EXYNOS_FB} += exynos/ obj-${CONFIG_VIDEO_ROCKCHIP} += rockchip/ obj-${CONFIG_VIDEO_STM32} += stm32/ diff --git a/drivers/video/lp855x_backlight.c b/drivers/video/lp855x_backlight.c new file mode 100644 index 00000000000..5debc0aa453 --- /dev/null +++ b/drivers/video/lp855x_backlight.c @@ -0,0 +1,302 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2011 Texas Instruments + * Copyright (c) 2024 Svyatoslav Ryhel clamor95@gmail.com + */ + +#define LOG_CATEGORY UCLASS_PANEL_BACKLIGHT + +#include <malloc.h> +#include <backlight.h> +#include <dm.h> +#include <dm/devres.h> +#include <i2c.h> +#include <log.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <asm/gpio.h> +#include <power/regulator.h> + +#define LP855x_MIN_BRIGHTNESS 0x00 +#define LP855x_MAX_BRIGHTNESS 0xff + +/* LP8550/1/2/3/6 Registers */ +#define LP855X_BRIGHTNESS_CTRL 0x00 +#define LP855X_DEVICE_CTRL 0x01 +#define LP855X_EEPROM_START 0xa0 +#define LP855X_EEPROM_END 0xa7 +#define LP8556_EPROM_START 0x98 +#define LP8556_EPROM_END 0xaf + +/* LP8555/7 Registers */ +#define LP8557_BL_CMD 0x00 +#define LP8557_BL_MASK 0x01 +#define LP8557_BL_ON 0x01 +#define LP8557_BL_OFF 0x00 +#define LP8557_BRIGHTNESS_CTRL 0x04 +#define LP8557_CONFIG 0x10 +#define LP8555_EPROM_START 0x10 +#define LP8555_EPROM_END 0x7a +#define LP8557_EPROM_START 0x10 +#define LP8557_EPROM_END 0x1e + +struct lp855x_rom_data { + u8 addr; + u8 val; +}; + +struct lp855x_backlight_priv; + +/* + * struct lp855x_device_config + * @pre_init_device: init device function call before updating the brightness + * @reg_brightness: register address for brigthenss control + * @reg_devicectrl: register address for device control + * @post_init_device: late init device function call + */ +struct lp855x_device_config { + int (*pre_init_device)(struct udevice *dev); + u8 reg_brightness; + u8 reg_devicectrl; + u8 reg_eepromstart; + u8 reg_eepromend; + int (*post_init_device)(struct udevice *dev); +}; + +struct lp855x_backlight_priv { + struct udevice *supply; /* regulator for VDD input */ + struct udevice *enable; /* regulator for EN/VDDIO input */ + + u8 device_control; + u8 initial_brightness; + + int size_program; + struct lp855x_rom_data *rom_data; + struct lp855x_device_config *cfg; +}; + +static int lp855x_backlight_enable(struct udevice *dev) +{ + struct lp855x_backlight_priv *priv = dev_get_priv(dev); + int ret; + + ret = regulator_set_enable_if_allowed(priv->supply, 1); + if (ret) { + log_debug("%s: enabling power-supply failed (%d)\n", + __func__, ret); + return ret; + } + + ret = regulator_set_enable_if_allowed(priv->enable, 1); + if (ret) { + log_debug("%s: enabling enable-supply failed (%d)\n", + __func__, ret); + return ret; + } + mdelay(2); + + if (priv->cfg->pre_init_device) { + ret = priv->cfg->pre_init_device(dev); + if (ret) { + log_debug("%s: pre init device err: %d\n", + __func__, ret); + return ret; + } + } + + ret = dm_i2c_reg_write(dev, priv->cfg->reg_brightness, + priv->initial_brightness); + if (ret) + return ret; + + ret = dm_i2c_reg_write(dev, priv->cfg->reg_devicectrl, + priv->device_control); + if (ret) + return ret; + + if (priv->size_program > 0) { + int i; + u8 val, addr; + + for (i = 0; i < priv->size_program; i++) { + addr = priv->rom_data[i].addr; + val = priv->rom_data[i].val; + + if (addr < priv->cfg->reg_eepromstart && + addr > priv->cfg->reg_eepromend) + continue; + + ret = dm_i2c_reg_write(dev, addr, val); + if (ret) + return ret; + } + } + + if (priv->cfg->post_init_device) { + ret = priv->cfg->post_init_device(dev); + if (ret) { + log_debug("%s: post init device err: %d\n", + __func__, ret); + return ret; + } + } + + return 0; +} + +static int lp855x_backlight_set_brightness(struct udevice *dev, int percent) +{ + struct lp855x_backlight_priv *priv = dev_get_priv(dev); + + if (percent == BACKLIGHT_DEFAULT) + percent = priv->initial_brightness; + + if (percent < LP855x_MIN_BRIGHTNESS) + percent = LP855x_MIN_BRIGHTNESS; + + if (percent > LP855x_MAX_BRIGHTNESS) + percent = LP855x_MAX_BRIGHTNESS; + + /* Set brightness level */ + return dm_i2c_reg_write(dev, priv->cfg->reg_brightness, + percent); +} + +static int lp855x_backlight_probe(struct udevice *dev) +{ + struct lp855x_backlight_priv *priv = dev_get_priv(dev); + int rom_length, ret; + + if (device_get_uclass_id(dev->parent) != UCLASS_I2C) + return -EPROTONOSUPPORT; + + priv->cfg = (struct lp855x_device_config *)dev_get_driver_data(dev); + + dev_read_u8(dev, "dev-ctrl", &priv->device_control); + dev_read_u8(dev, "init-brt", &priv->initial_brightness); + + /* Fill ROM platform data if defined */ + rom_length = dev_get_child_count(dev); + if (rom_length > 0) { + struct lp855x_rom_data *rom; + ofnode child; + int i = 0; + + rom = devm_kcalloc(dev, rom_length, sizeof(*rom), GFP_KERNEL); + if (!rom) + return -ENOMEM; + + dev_for_each_subnode(child, dev) { + ofnode_read_u8(child, "rom-addr", &rom[i].addr); + ofnode_read_u8(child, "rom-val", &rom[i].val); + i++; + } + + priv->size_program = rom_length; + priv->rom_data = &rom[0]; + } + + ret = uclass_get_device_by_phandle(UCLASS_REGULATOR, dev, + "power-supply", &priv->supply); + if (ret) { + log_err("%s: cannot get power-supply: ret = %d\n", __func__, ret); + return ret; + } + + ret = uclass_get_device_by_phandle(UCLASS_REGULATOR, dev, + "enable-supply", &priv->enable); + if (ret) { + log_err("%s: cannot get enable-supply: ret = %d\n", __func__, ret); + return ret; + } + + return 0; +} + +static const struct backlight_ops lp855x_backlight_ops = { + .enable = lp855x_backlight_enable, + .set_brightness = lp855x_backlight_set_brightness, +}; + +static int lp8556_bl_rst(struct udevice *dev) +{ + int ret; + + /* Reset backlight after updating EPROM settings */ + ret = dm_i2c_reg_clrset(dev, LP855X_DEVICE_CTRL, LP8557_BL_MASK, + LP8557_BL_OFF); + if (ret) + return ret; + + mdelay(10); + + return dm_i2c_reg_clrset(dev, LP855X_DEVICE_CTRL, LP8557_BL_MASK, + LP8557_BL_ON); +} + +static int lp8557_bl_off(struct udevice *dev) +{ + /* BL_ON = 0 before updating EPROM settings */ + return dm_i2c_reg_clrset(dev, LP8557_BL_CMD, LP8557_BL_MASK, + LP8557_BL_OFF); +} + +static int lp8557_bl_on(struct udevice *dev) +{ + /* BL_ON = 1 after updating EPROM settings */ + return dm_i2c_reg_clrset(dev, LP8557_BL_CMD, LP8557_BL_MASK, + LP8557_BL_ON); +} + +static struct lp855x_device_config lp855x_dev_cfg = { + .reg_brightness = LP855X_BRIGHTNESS_CTRL, + .reg_devicectrl = LP855X_DEVICE_CTRL, + .reg_eepromstart = LP855X_EEPROM_START, + .reg_eepromend = LP855X_EEPROM_END, +}; + +static struct lp855x_device_config lp8555_dev_cfg = { + .reg_brightness = LP8557_BRIGHTNESS_CTRL, + .reg_devicectrl = LP8557_CONFIG, + .reg_eepromstart = LP8555_EPROM_START, + .reg_eepromend = LP8555_EPROM_END, + .pre_init_device = lp8557_bl_off, + .post_init_device = lp8557_bl_on, +}; + +static struct lp855x_device_config lp8556_dev_cfg = { + .reg_brightness = LP855X_BRIGHTNESS_CTRL, + .reg_devicectrl = LP855X_DEVICE_CTRL, + .reg_eepromstart = LP8556_EPROM_START, + .reg_eepromend = LP8556_EPROM_END, + .post_init_device = lp8556_bl_rst, +}; + +static struct lp855x_device_config lp8557_dev_cfg = { + .reg_brightness = LP8557_BRIGHTNESS_CTRL, + .reg_devicectrl = LP8557_CONFIG, + .reg_eepromstart = LP8557_EPROM_START, + .reg_eepromend = LP8557_EPROM_END, + .pre_init_device = lp8557_bl_off, + .post_init_device = lp8557_bl_on, +}; + +static const struct udevice_id lp855x_backlight_ids[] = { + { .compatible = "ti,lp8550", .data = (ulong)&lp855x_dev_cfg }, + { .compatible = "ti,lp8551", .data = (ulong)&lp855x_dev_cfg }, + { .compatible = "ti,lp8552", .data = (ulong)&lp855x_dev_cfg }, + { .compatible = "ti,lp8553", .data = (ulong)&lp855x_dev_cfg }, + { .compatible = "ti,lp8555", .data = (ulong)&lp8555_dev_cfg }, + { .compatible = "ti,lp8556", .data = (ulong)&lp8556_dev_cfg }, + { .compatible = "ti,lp8557", .data = (ulong)&lp8557_dev_cfg }, + { } +}; + +U_BOOT_DRIVER(lp855x_backlight) = { + .name = "lp855x_backlight", + .id = UCLASS_PANEL_BACKLIGHT, + .of_match = lp855x_backlight_ids, + .probe = lp855x_backlight_probe, + .ops = &lp855x_backlight_ops, + .priv_auto = sizeof(struct lp855x_backlight_priv), +};