forked from Minki/linux
f00207b255
This patch creates a common structure for LCD backlight using PWM timer to be used by various Samsung boards. Signed-off-by: Banajit Goswami <banajit.g@samsung.com> Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
150 lines
4.5 KiB
C
150 lines
4.5 KiB
C
/* linux/arch/arm/plat-samsung/dev-backlight.c
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*
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* Copyright (c) 2011 Samsung Electronics Co., Ltd.
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* http://www.samsung.com
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*
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* Common infrastructure for PWM Backlight for Samsung boards
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/gpio.h>
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#include <linux/platform_device.h>
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#include <linux/io.h>
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#include <linux/pwm_backlight.h>
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#include <plat/devs.h>
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#include <plat/gpio-cfg.h>
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#include <plat/backlight.h>
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static int samsung_bl_init(struct device *dev)
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{
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int ret = 0;
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struct platform_device *timer_dev =
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container_of(dev->parent, struct platform_device, dev);
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struct samsung_bl_gpio_info *bl_gpio_info =
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timer_dev->dev.platform_data;
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ret = gpio_request(bl_gpio_info->no, "Backlight");
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if (ret) {
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printk(KERN_ERR "failed to request GPIO for LCD Backlight\n");
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return ret;
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}
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/* Configure GPIO pin with specific GPIO function for PWM timer */
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s3c_gpio_cfgpin(bl_gpio_info->no, bl_gpio_info->func);
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return 0;
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}
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static void samsung_bl_exit(struct device *dev)
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{
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struct platform_device *timer_dev =
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container_of(dev->parent, struct platform_device, dev);
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struct samsung_bl_gpio_info *bl_gpio_info =
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timer_dev->dev.platform_data;
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s3c_gpio_cfgpin(bl_gpio_info->no, S3C_GPIO_OUTPUT);
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gpio_free(bl_gpio_info->no);
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}
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/* Initialize few important fields of platform_pwm_backlight_data
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* structure with default values. These fields can be overridden by
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* board-specific values sent from machine file.
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* For ease of operation, these fields are initialized with values
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* used by most samsung boards.
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* Users has the option of sending info about other parameters
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* for their specific boards
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*/
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static struct platform_pwm_backlight_data samsung_dfl_bl_data __initdata = {
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.max_brightness = 255,
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.dft_brightness = 255,
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.pwm_period_ns = 78770,
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.init = samsung_bl_init,
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.exit = samsung_bl_exit,
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};
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static struct platform_device samsung_dfl_bl_device __initdata = {
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.name = "pwm-backlight",
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};
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/* samsung_bl_set - Set board specific data (if any) provided by user for
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* PWM Backlight control and register specific PWM and backlight device.
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* @gpio_info: structure containing GPIO info for PWM timer
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* @bl_data: structure containing Backlight control data
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*/
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void samsung_bl_set(struct samsung_bl_gpio_info *gpio_info,
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struct platform_pwm_backlight_data *bl_data)
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{
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int ret = 0;
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struct platform_device *samsung_bl_device;
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struct platform_pwm_backlight_data *samsung_bl_data;
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samsung_bl_device = kmemdup(&samsung_dfl_bl_device,
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sizeof(struct platform_device), GFP_KERNEL);
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if (!samsung_bl_device) {
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printk(KERN_ERR "%s: no memory for platform dev\n", __func__);
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return;
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}
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samsung_bl_data = s3c_set_platdata(&samsung_dfl_bl_data,
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sizeof(struct platform_pwm_backlight_data), samsung_bl_device);
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if (!samsung_bl_data) {
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printk(KERN_ERR "%s: no memory for platform dev\n", __func__);
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goto err_data;
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}
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/* Copy board specific data provided by user */
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samsung_bl_data->pwm_id = bl_data->pwm_id;
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samsung_bl_device->dev.parent =
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&s3c_device_timer[samsung_bl_data->pwm_id].dev;
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if (bl_data->max_brightness)
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samsung_bl_data->max_brightness = bl_data->max_brightness;
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if (bl_data->dft_brightness)
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samsung_bl_data->dft_brightness = bl_data->dft_brightness;
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if (bl_data->lth_brightness)
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samsung_bl_data->lth_brightness = bl_data->lth_brightness;
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if (bl_data->pwm_period_ns)
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samsung_bl_data->pwm_period_ns = bl_data->pwm_period_ns;
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if (bl_data->init)
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samsung_bl_data->init = bl_data->init;
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if (bl_data->notify)
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samsung_bl_data->notify = bl_data->notify;
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if (bl_data->exit)
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samsung_bl_data->exit = bl_data->exit;
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if (bl_data->check_fb)
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samsung_bl_data->check_fb = bl_data->check_fb;
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/* Keep the GPIO info for future use */
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s3c_device_timer[samsung_bl_data->pwm_id].dev.platform_data = gpio_info;
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/* Register the specific PWM timer dev for Backlight control */
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ret = platform_device_register(
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&s3c_device_timer[samsung_bl_data->pwm_id]);
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if (ret) {
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printk(KERN_ERR "failed to register pwm timer for backlight: %d\n", ret);
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goto err_plat_reg1;
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}
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/* Register the Backlight dev */
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ret = platform_device_register(samsung_bl_device);
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if (ret) {
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printk(KERN_ERR "failed to register backlight device: %d\n", ret);
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goto err_plat_reg2;
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}
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return;
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err_plat_reg2:
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platform_device_unregister(&s3c_device_timer[samsung_bl_data->pwm_id]);
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err_plat_reg1:
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kfree(samsung_bl_data);
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err_data:
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kfree(samsung_bl_device);
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return;
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}
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