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/*
* Backlight LEDs driver for MAX8831
*
* Copyright (c) 2008-2013, NVIDIA CORPORATION. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/fb.h>
#include <linux/backlight.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/err.h>
#include <linux/mfd/max8831.h>
#include <linux/max8831_backlight.h>
#include <linux/regulator/consumer.h>
#include <linux/platform_device.h>
struct max8831_backlight_data {
struct device *max8831_dev;
int id;
int current_brightness;
struct regulator *regulator;
int (*notify)(struct device *dev, int brightness);
bool (*is_powered)(void);
};
static int max8831_backlight_set(struct backlight_device *bl, int brightness)
{
struct max8831_backlight_data *data = bl_get_data(bl);
struct device *dev = data->max8831_dev;
/* ranges from 0-255 */
data->current_brightness = brightness;
if (data->is_powered)
if (!data->is_powered())
return 0;
if (data->id == MAX8831_BL_LEDS) {
/* map 0-255 brightness to max8831 range */
brightness = brightness * MAX8831_BL_LEDS_MAX_CURR / 255;
if (brightness == 0) {
max8831_update_bits(dev, MAX8831_CTRL,
(MAX8831_CTRL_LED1_ENB | MAX8831_CTRL_LED2_ENB), 0);
} else {
max8831_update_bits(dev, MAX8831_CTRL,
(MAX8831_CTRL_LED1_ENB | MAX8831_CTRL_LED2_ENB),
(MAX8831_CTRL_LED1_ENB | MAX8831_CTRL_LED2_ENB));
max8831_write(dev, MAX8831_CURRENT_CTRL_LED1,
brightness);
max8831_write(dev, MAX8831_CURRENT_CTRL_LED2,
brightness);
}
}
return 0;
}
static int max8831_backlight_update_status(struct backlight_device *bl)
{
struct max8831_backlight_data *data = bl_get_data(bl);
int brightness = bl->props.brightness;
/*
if (bl->props.power != FB_BLANK_UNBLANK)
brightness = 0;
if (bl->props.fb_blank != FB_BLANK_UNBLANK)
brightness = 0;
*/
if (data->notify)
brightness = data->notify(data->max8831_dev, brightness);
return max8831_backlight_set(bl, brightness);
}
static int max8831_backlight_get_brightness(struct backlight_device *bl)
{
struct max8831_backlight_data *data = bl_get_data(bl);
return data->current_brightness;
}
static const struct backlight_ops max8831_backlight_ops = {
.update_status = max8831_backlight_update_status,
.get_brightness = max8831_backlight_get_brightness,
};
static int max8831_bl_probe(struct platform_device *pdev)
{
struct max8831_backlight_data *data;
struct backlight_device *bl;
struct backlight_properties props;
struct platform_max8831_backlight_data *pData = pdev->dev.platform_data;
data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
if (data == NULL)
return -ENOMEM;
data->max8831_dev = pdev->dev.parent;
data->current_brightness = 0;
data->id = pdev->id;
data->notify = pData->notify;
data->is_powered = pData->is_powered;
data->regulator = regulator_get(data->max8831_dev,
"vin");
if (IS_ERR(data->regulator)) {
dev_err(&pdev->dev, "%s: Unable to get the backlight regulator\n",
__func__);
data->regulator = NULL;
} else {
regulator_enable(data->regulator);
}
props.type = BACKLIGHT_RAW;
props.max_brightness = 255;
bl = backlight_device_register(pdev->name, data->max8831_dev, data,
&max8831_backlight_ops, &props);
if (IS_ERR(bl)) {
dev_err(&pdev->dev, "failed to register backlight\n");
return PTR_ERR(bl);
}
bl->props.brightness = pData->dft_brightness;
platform_set_drvdata(pdev, bl);
backlight_update_status(bl);
return 0;
}
static int max8831_bl_remove(struct platform_device *pdev)
{
struct backlight_device *bl = platform_get_drvdata(pdev);
struct max8831_backlight_data *data = bl_get_data(bl);
if (data->regulator != NULL)
regulator_put(data->regulator);
backlight_device_unregister(bl);
kfree(data);
return 0;
}
#ifdef CONFIG_PM
static int max8831_bl_suspend(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct backlight_device *bl = platform_get_drvdata(pdev);
struct max8831_backlight_data *data = bl_get_data(bl);
int ret;
ret = max8831_backlight_set(bl, 0);
if (data->regulator)
regulator_disable(data->regulator);
return ret;
}
static int max8831_bl_resume(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct backlight_device *bl = platform_get_drvdata(pdev);
struct max8831_backlight_data *data = bl_get_data(bl);
if (data->regulator)
regulator_enable(data->regulator);
backlight_update_status(bl);
return 0;
}
static const struct dev_pm_ops max8831_bl_pm_ops = {
.suspend = max8831_bl_suspend,
.resume = max8831_bl_resume,
};
#endif
static struct platform_driver max8831_bl_driver = {
.driver = {
.name = "max8831_display_bl",
.owner = THIS_MODULE,
#ifdef CONFIG_PM
.pm = &max8831_bl_pm_ops,
#endif
},
.probe = max8831_bl_probe,
.remove = max8831_bl_remove,
};
module_platform_driver(max8831_bl_driver);
MODULE_AUTHOR("Chaitanya Bandi <bandik@nvidia.com>");
MODULE_DESCRIPTION("MAX8831 Backlight display driver");
MODULE_LICENSE("GPL v2");
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