From f00207b255f59ebedc5965c2ab0bd1cefae70f92 Mon Sep 17 00:00:00 2001 From: Banajit Goswami Date: Wed, 20 Jul 2011 23:44:21 +0900 Subject: ARM: SAMSUNG: Create a common infrastructure for PWM backlight support This patch creates a common structure for LCD backlight using PWM timer to be used by various Samsung boards. Signed-off-by: Banajit Goswami Signed-off-by: Kukjin Kim --- arch/arm/plat-samsung/Kconfig | 6 + arch/arm/plat-samsung/Makefile | 1 + arch/arm/plat-samsung/dev-backlight.c | 149 +++++++++++++++++++++++++ arch/arm/plat-samsung/include/plat/backlight.h | 26 +++++ 4 files changed, 182 insertions(+) create mode 100644 arch/arm/plat-samsung/dev-backlight.c create mode 100644 arch/arm/plat-samsung/include/plat/backlight.h (limited to 'arch/arm/plat-samsung') diff --git a/arch/arm/plat-samsung/Kconfig b/arch/arm/plat-samsung/Kconfig index 4d79519d19a4..b3e10659e4b8 100644 --- a/arch/arm/plat-samsung/Kconfig +++ b/arch/arm/plat-samsung/Kconfig @@ -280,6 +280,12 @@ config SAMSUNG_DEV_PWM help Compile in platform device definition for PWM Timer +config SAMSUNG_DEV_BACKLIGHT + bool + depends on SAMSUNG_DEV_PWM + help + Compile in platform device definition LCD backlight with PWM Timer + config S3C24XX_PWM bool "PWM device support" select HAVE_PWM diff --git a/arch/arm/plat-samsung/Makefile b/arch/arm/plat-samsung/Makefile index 53eb15b0a07d..853764ba8cc5 100644 --- a/arch/arm/plat-samsung/Makefile +++ b/arch/arm/plat-samsung/Makefile @@ -59,6 +59,7 @@ obj-$(CONFIG_SAMSUNG_DEV_IDE) += dev-ide.o obj-$(CONFIG_SAMSUNG_DEV_TS) += dev-ts.o obj-$(CONFIG_SAMSUNG_DEV_KEYPAD) += dev-keypad.o obj-$(CONFIG_SAMSUNG_DEV_PWM) += dev-pwm.o +obj-$(CONFIG_SAMSUNG_DEV_BACKLIGHT) += dev-backlight.o # DMA support diff --git a/arch/arm/plat-samsung/dev-backlight.c b/arch/arm/plat-samsung/dev-backlight.c new file mode 100644 index 000000000000..3cedd4c407af --- /dev/null +++ b/arch/arm/plat-samsung/dev-backlight.c @@ -0,0 +1,149 @@ +/* linux/arch/arm/plat-samsung/dev-backlight.c + * + * Copyright (c) 2011 Samsung Electronics Co., Ltd. + * http://www.samsung.com + * + * Common infrastructure for PWM Backlight for Samsung boards + * + * 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 +#include +#include +#include + +#include +#include +#include + +static int samsung_bl_init(struct device *dev) +{ + int ret = 0; + struct platform_device *timer_dev = + container_of(dev->parent, struct platform_device, dev); + struct samsung_bl_gpio_info *bl_gpio_info = + timer_dev->dev.platform_data; + + ret = gpio_request(bl_gpio_info->no, "Backlight"); + if (ret) { + printk(KERN_ERR "failed to request GPIO for LCD Backlight\n"); + return ret; + } + + /* Configure GPIO pin with specific GPIO function for PWM timer */ + s3c_gpio_cfgpin(bl_gpio_info->no, bl_gpio_info->func); + + return 0; +} + +static void samsung_bl_exit(struct device *dev) +{ + struct platform_device *timer_dev = + container_of(dev->parent, struct platform_device, dev); + struct samsung_bl_gpio_info *bl_gpio_info = + timer_dev->dev.platform_data; + + s3c_gpio_cfgpin(bl_gpio_info->no, S3C_GPIO_OUTPUT); + gpio_free(bl_gpio_info->no); +} + +/* Initialize few important fields of platform_pwm_backlight_data + * structure with default values. These fields can be overridden by + * board-specific values sent from machine file. + * For ease of operation, these fields are initialized with values + * used by most samsung boards. + * Users has the option of sending info about other parameters + * for their specific boards + */ + +static struct platform_pwm_backlight_data samsung_dfl_bl_data __initdata = { + .max_brightness = 255, + .dft_brightness = 255, + .pwm_period_ns = 78770, + .init = samsung_bl_init, + .exit = samsung_bl_exit, +}; + +static struct platform_device samsung_dfl_bl_device __initdata = { + .name = "pwm-backlight", +}; + +/* samsung_bl_set - Set board specific data (if any) provided by user for + * PWM Backlight control and register specific PWM and backlight device. + * @gpio_info: structure containing GPIO info for PWM timer + * @bl_data: structure containing Backlight control data + */ +void samsung_bl_set(struct samsung_bl_gpio_info *gpio_info, + struct platform_pwm_backlight_data *bl_data) +{ + int ret = 0; + struct platform_device *samsung_bl_device; + struct platform_pwm_backlight_data *samsung_bl_data; + + samsung_bl_device = kmemdup(&samsung_dfl_bl_device, + sizeof(struct platform_device), GFP_KERNEL); + if (!samsung_bl_device) { + printk(KERN_ERR "%s: no memory for platform dev\n", __func__); + return; + } + + samsung_bl_data = s3c_set_platdata(&samsung_dfl_bl_data, + sizeof(struct platform_pwm_backlight_data), samsung_bl_device); + if (!samsung_bl_data) { + printk(KERN_ERR "%s: no memory for platform dev\n", __func__); + goto err_data; + } + + /* Copy board specific data provided by user */ + samsung_bl_data->pwm_id = bl_data->pwm_id; + samsung_bl_device->dev.parent = + &s3c_device_timer[samsung_bl_data->pwm_id].dev; + + if (bl_data->max_brightness) + samsung_bl_data->max_brightness = bl_data->max_brightness; + if (bl_data->dft_brightness) + samsung_bl_data->dft_brightness = bl_data->dft_brightness; + if (bl_data->lth_brightness) + samsung_bl_data->lth_brightness = bl_data->lth_brightness; + if (bl_data->pwm_period_ns) + samsung_bl_data->pwm_period_ns = bl_data->pwm_period_ns; + if (bl_data->init) + samsung_bl_data->init = bl_data->init; + if (bl_data->notify) + samsung_bl_data->notify = bl_data->notify; + if (bl_data->exit) + samsung_bl_data->exit = bl_data->exit; + if (bl_data->check_fb) + samsung_bl_data->check_fb = bl_data->check_fb; + + /* Keep the GPIO info for future use */ + s3c_device_timer[samsung_bl_data->pwm_id].dev.platform_data = gpio_info; + + /* Register the specific PWM timer dev for Backlight control */ + ret = platform_device_register( + &s3c_device_timer[samsung_bl_data->pwm_id]); + if (ret) { + printk(KERN_ERR "failed to register pwm timer for backlight: %d\n", ret); + goto err_plat_reg1; + } + + /* Register the Backlight dev */ + ret = platform_device_register(samsung_bl_device); + if (ret) { + printk(KERN_ERR "failed to register backlight device: %d\n", ret); + goto err_plat_reg2; + } + + return; + +err_plat_reg2: + platform_device_unregister(&s3c_device_timer[samsung_bl_data->pwm_id]); +err_plat_reg1: + kfree(samsung_bl_data); +err_data: + kfree(samsung_bl_device); + return; +} diff --git a/arch/arm/plat-samsung/include/plat/backlight.h b/arch/arm/plat-samsung/include/plat/backlight.h new file mode 100644 index 000000000000..51d8da846a62 --- /dev/null +++ b/arch/arm/plat-samsung/include/plat/backlight.h @@ -0,0 +1,26 @@ +/* linux/arch/arm/plat-samsung/include/plat/backlight.h + * + * Copyright (c) 2011 Samsung Electronics Co., Ltd. + * http://www.samsung.com + * + * 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 __ASM_PLAT_BACKLIGHT_H +#define __ASM_PLAT_BACKLIGHT_H __FILE__ + +/* samsung_bl_gpio_info - GPIO info for PWM Backlight control + * @no: GPIO number for PWM timer out + * @func: Special function of GPIO line for PWM timer + */ +struct samsung_bl_gpio_info { + int no; + int func; +}; + +extern void samsung_bl_set(struct samsung_bl_gpio_info *gpio_info, + struct platform_pwm_backlight_data *bl_data); + +#endif /* __ASM_PLAT_BACKLIGHT_H */ -- cgit v1.2.3