/*
* Backlight driver for Dialog Semiconductor DA9030/DA9034
*
* Copyright (C) 2008 Compulab, Ltd.
* Mike Rapoport <mike@compulab.co.il>
*
* Copyright (C) 2006-2008 Marvell International Ltd.
* Eric Miao <eric.miao@marvell.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/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/fb.h>
#include <linux/backlight.h>
#include <linux/mfd/da903x.h>
#include <linux/slab.h>
#include <linux/module.h>
#define DA9030_WLED_CONTROL 0x25
#define DA9030_WLED_CP_EN (1 << 6)
#define DA9030_WLED_TRIM(x) ((x) & 0x7)
#define DA9034_WLED_CONTROL1 0x3C
#define DA9034_WLED_CONTROL2 0x3D
#define DA9034_WLED_ISET(x) ((x) & 0x1f)
#define DA9034_WLED_BOOST_EN (1 << 5)
#define DA9030_MAX_BRIGHTNESS 7
#define DA9034_MAX_BRIGHTNESS 0x7f
struct da903x_backlight_data {
struct device *da903x_dev;
int id;
int current_brightness;
};
static int da903x_backlight_set(struct backlight_device *bl, int brightness)
{
struct da903x_backlight_data *data = bl_get_data(bl);
struct device *dev = data->da903x_dev;
uint8_t val;
int ret = 0;
switch (data->id) {
case DA9034_ID_WLED:
ret = da903x_update(dev, DA9034_WLED_CONTROL1,
brightness, 0x7f);
if (ret)
return ret;
if (data->current_brightness && brightness == 0)
ret = da903x_clr_bits(dev,
DA9034_WLED_CONTROL2,
DA9034_WLED_BOOST_EN);
if (data->current_brightness == 0 && brightness)
ret = da903x_set_bits(dev,
DA9034_WLED_CONTROL2,
DA9034_WLED_BOOST_EN);
break;
case DA9030_ID_WLED:
val = DA9030_WLED_TRIM(brightness);
val |= brightness ? DA9030_WLED_CP_EN : 0;
ret = da903x_write(dev, DA9030_WLED_CONTROL, val);
break;
}
if (ret)
return ret;
data->current_brightness = brightness;
return 0;
}
static int da903x_backlight_update_status(struct backlight_device *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 (bl->props.state & BL_CORE_SUSPENDED)
brightness = 0;
return da903x_backlight_set(bl, brightness);
}
static int da903x_backlight_get_brightness(struct backlight_device *bl)
{
struct da903x_backlight_data *data = bl_get_data(bl);
return data->current_brightness;
}
static const struct backlight_ops da903x_backlight_ops = {
.options = BL_CORE_SUSPENDRESUME,
.update_status = da903x_backlight_update_status,
.get_brightness = da903x_backlight_get_brightness,
};
static int da903x_backlight_probe(struct platform_device *pdev)
{
struct da9034_backlight_pdata *pdata = dev_get_platdata(&pdev->dev);
struct da903x_backlight_data *data;
struct backlight_device *bl;
struct backlight_properties props;
int max_brightness;
data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
if (data == NULL)
return -ENOMEM;
switch (pdev->id) {
case DA9030_ID_WLED:
max_brightness = DA9030_MAX_BRIGHTNESS;
break;
case DA9034_ID_WLED:
max_brightness = DA9034_MAX_BRIGHTNESS;
break;
default:
dev_err(&pdev->dev, "invalid backlight device ID(%d)\n",
pdev->id);
return -EINVAL;
}
data->id = pdev->id;
data->da903x_dev = pdev->dev.parent;
data->current_brightness = 0;
/* adjust the WLED output current */
if (pdata)
da903x_write(data->da903x_dev, DA9034_WLED_CONTROL2,
DA9034_WLED_ISET(pdata->output_current));
memset(&props, 0, sizeof(props));
props.type = BACKLIGHT_RAW;
props.max_brightness = max_brightness;
bl = devm_backlight_device_register(&pdev->dev, pdev->name,
data->da903x_dev, data,
&da903x_backlight_ops, &props);
if (IS_ERR(bl)) {
dev_err(&pdev->dev, "failed to register backlight\n");
return PTR_ERR(bl);
}
bl->props.brightness = max_brightness;
platform_set_drvdata(pdev, bl);
backlight_update_status(bl);
return 0;
}
static struct platform_driver da903x_backlight_driver = {
.driver = {
.name = "da903x-backlight",
},
.probe = da903x_backlight_probe,
};
module_platform_driver(da903x_backlight_driver);
MODULE_DESCRIPTION("Backlight Driver for Dialog Semiconductor DA9030/DA9034");
MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:da903x-backlight");
