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/*
* linux/drivers/video/backlight/tegra_pwm_bl.c
*
* Tegra pwm backlight driver
*
* Copyright (C) 2011 NVIDIA Corporation
* Author: Renuka Apte <rapte@nvidia.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.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/fb.h>
#include <linux/backlight.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/tegra_pwm_bl.h>
#include <linux/gpio.h>
#include <mach/dc.h>
struct tegra_pwm_bl_data {
struct device *dev;
int which_dc;
int (*notify)(struct device *, int brightness);
struct tegra_dc_pwm_params params;
int (*check_fb)(struct device *dev, struct fb_info *info);
};
static int tegra_pwm_backlight_update_status(struct backlight_device *bl)
{
struct tegra_pwm_bl_data *tbl = dev_get_drvdata(&bl->dev);
int brightness = bl->props.brightness;
int max = bl->props.max_brightness;
struct tegra_dc *dc;
if (bl->props.power != FB_BLANK_UNBLANK)
brightness = 0;
if (bl->props.fb_blank != FB_BLANK_UNBLANK)
brightness = 0;
if (tbl->notify)
brightness = tbl->notify(tbl->dev, brightness);
if (brightness > max)
dev_err(&bl->dev, "Invalid brightness value: %d max: %d\n",
brightness, max);
#if defined(CONFIG_ARCH_TEGRA_2x_SOC)
/* map API brightness range from (0~255) to hw range (0~128) */
tbl->params.duty_cycle = (brightness * 128) / 255;
#else
tbl->params.duty_cycle = brightness & 0xFF;
#endif
/* Call tegra display controller function to update backlight */
dc = tegra_dc_get_dc(tbl->which_dc);
if (dc)
tegra_dc_config_pwm(dc, &tbl->params);
else
dev_err(&bl->dev, "tegra display controller not available\n");
return 0;
}
static int tegra_pwm_backlight_get_brightness(struct backlight_device *bl)
{
return bl->props.brightness;
}
static int tegra_pwm_backlight_check_fb(struct backlight_device *bl,
struct fb_info *info)
{
struct tegra_pwm_bl_data *tbl = dev_get_drvdata(&bl->dev);
return !tbl->check_fb || tbl->check_fb(tbl->dev, info);
}
static const struct backlight_ops tegra_pwm_backlight_ops = {
.update_status = tegra_pwm_backlight_update_status,
.get_brightness = tegra_pwm_backlight_get_brightness,
.check_fb = tegra_pwm_backlight_check_fb,
};
static int tegra_pwm_backlight_probe(struct platform_device *pdev)
{
struct backlight_properties props;
struct platform_tegra_pwm_backlight_data *data;
struct backlight_device *bl;
struct tegra_pwm_bl_data *tbl;
int ret;
data = pdev->dev.platform_data;
if (!data) {
dev_err(&pdev->dev, "failed to find platform data\n");
return -EINVAL;
}
tbl = kzalloc(sizeof(*tbl), GFP_KERNEL);
if (!tbl) {
dev_err(&pdev->dev, "no memory for state\n");
ret = -ENOMEM;
goto err_alloc;
}
tbl->dev = &pdev->dev;
tbl->which_dc = data->which_dc;
tbl->notify = data->notify;
tbl->check_fb = data->check_fb;
tbl->params.which_pwm = data->which_pwm;
tbl->params.gpio_conf_to_sfio = data->gpio_conf_to_sfio;
tbl->params.period = data->period;
tbl->params.clk_div = data->clk_div;
tbl->params.clk_select = data->clk_select;
/* If backlight pin is sfio, request for it */
if (gpio_is_valid(tbl->params.gpio_conf_to_sfio)) {
ret = gpio_request(tbl->params.gpio_conf_to_sfio, "disp_bl");
if (ret)
dev_err(&pdev->dev, "backlight gpio request failed\n");
}
memset(&props, 0, sizeof(struct backlight_properties));
props.type = BACKLIGHT_RAW;
props.max_brightness = data->max_brightness;
bl = backlight_device_register(dev_name(&pdev->dev), &pdev->dev, tbl,
&tegra_pwm_backlight_ops, &props);
if (IS_ERR(bl)) {
dev_err(&pdev->dev, "failed to register backlight\n");
ret = PTR_ERR(bl);
goto err_bl;
}
bl->props.brightness = data->dft_brightness;
if (gpio_is_valid(tbl->params.gpio_conf_to_sfio))
gpio_free(tbl->params.gpio_conf_to_sfio);
backlight_update_status(bl);
platform_set_drvdata(pdev, bl);
return 0;
err_bl:
kfree(tbl);
err_alloc:
return ret;
}
static int tegra_pwm_backlight_remove(struct platform_device *pdev)
{
struct backlight_device *bl = platform_get_drvdata(pdev);
struct tegra_pwm_bl_data *tbl = dev_get_drvdata(&bl->dev);
backlight_device_unregister(bl);
kfree(tbl);
return 0;
}
static struct platform_driver tegra_pwm_backlight_driver = {
.driver = {
.name = "tegra-pwm-bl",
.owner = THIS_MODULE,
},
.probe = tegra_pwm_backlight_probe,
.remove = tegra_pwm_backlight_remove,
};
static int __init tegra_pwm_backlight_init(void)
{
return platform_driver_register(&tegra_pwm_backlight_driver);
}
late_initcall(tegra_pwm_backlight_init);
static void __exit tegra_pwm_backlight_exit(void)
{
platform_driver_unregister(&tegra_pwm_backlight_driver);
}
module_exit(tegra_pwm_backlight_exit);
MODULE_DESCRIPTION("Tegra PWM Backlight Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:tegra-pwm-backlight");
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