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/*
* Backlight driver for Marvell Semiconductor 88PM8606
*
* Copyright (C) 2009 Marvell International Ltd.
* Haojian Zhuang <haojian.zhuang@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/init.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/fb.h>
#include <linux/i2c.h>
#include <linux/backlight.h>
#include <linux/mfd/88pm860x.h>
#include <linux/module.h>
#define MAX_BRIGHTNESS (0xFF)
#define MIN_BRIGHTNESS (0)
#define CURRENT_BITMASK (0x1F << 1)
struct pm860x_backlight_data {
struct pm860x_chip *chip;
struct i2c_client *i2c;
int current_brightness;
int port;
int pwm;
int iset;
int reg_duty_cycle;
int reg_always_on;
int reg_current;
};
static int backlight_power_set(struct pm860x_chip *chip, int port,
int on)
{
int ret = -EINVAL;
switch (port) {
case 0:
ret = on ? pm8606_osc_enable(chip, WLED1_DUTY) :
pm8606_osc_disable(chip, WLED1_DUTY);
break;
case 1:
ret = on ? pm8606_osc_enable(chip, WLED2_DUTY) :
pm8606_osc_disable(chip, WLED2_DUTY);
break;
case 2:
ret = on ? pm8606_osc_enable(chip, WLED3_DUTY) :
pm8606_osc_disable(chip, WLED3_DUTY);
break;
}
return ret;
}
static int pm860x_backlight_set(struct backlight_device *bl, int brightness)
{
struct pm860x_backlight_data *data = bl_get_data(bl);
struct pm860x_chip *chip = data->chip;
unsigned char value;
int ret;
if (brightness > MAX_BRIGHTNESS)
value = MAX_BRIGHTNESS;
else
value = brightness;
if (brightness)
backlight_power_set(chip, data->port, 1);
ret = pm860x_reg_write(data->i2c, data->reg_duty_cycle, value);
if (ret < 0)
goto out;
if ((data->current_brightness == 0) && brightness) {
if (data->iset) {
ret = pm860x_set_bits(data->i2c, data->reg_current,
CURRENT_BITMASK, data->iset);
if (ret < 0)
goto out;
}
if (data->pwm) {
ret = pm860x_set_bits(data->i2c, PM8606_PWM,
PM8606_PWM_FREQ_MASK, data->pwm);
if (ret < 0)
goto out;
}
if (brightness == MAX_BRIGHTNESS) {
/* set WLED_ON bit as 100% */
ret = pm860x_set_bits(data->i2c, data->reg_always_on,
PM8606_WLED_ON, PM8606_WLED_ON);
}
} else {
if (brightness == MAX_BRIGHTNESS) {
/* set WLED_ON bit as 100% */
ret = pm860x_set_bits(data->i2c, data->reg_always_on,
PM8606_WLED_ON, PM8606_WLED_ON);
} else {
/* clear WLED_ON bit since it's not 100% */
ret = pm860x_set_bits(data->i2c, data->reg_always_on,
PM8606_WLED_ON, 0);
}
}
if (ret < 0)
goto out;
if (brightness == 0)
backlight_power_set(chip, data->port, 0);
dev_dbg(chip->dev, "set brightness %d\n", value);
data->current_brightness = value;
return 0;
out:
dev_dbg(chip->dev, "set brightness %d failure with return value: %d\n",
value, ret);
return ret;
}
static int pm860x_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 pm860x_backlight_set(bl, brightness);
}
static int pm860x_backlight_get_brightness(struct backlight_device *bl)
{
struct pm860x_backlight_data *data = bl_get_data(bl);
struct pm860x_chip *chip = data->chip;
int ret;
ret = pm860x_reg_read(data->i2c, data->reg_duty_cycle);
if (ret < 0)
goto out;
data->current_brightness = ret;
dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness);
return data->current_brightness;
out:
return -EINVAL;
}
static const struct backlight_ops pm860x_backlight_ops = {
.options = BL_CORE_SUSPENDRESUME,
.update_status = pm860x_backlight_update_status,
.get_brightness = pm860x_backlight_get_brightness,
};
#ifdef CONFIG_OF
static int pm860x_backlight_dt_init(struct platform_device *pdev,
struct pm860x_backlight_data *data,
char *name)
{
struct device_node *nproot, *np;
int iset = 0;
nproot = of_node_get(pdev->dev.parent->of_node);
if (!nproot)
return -ENODEV;
nproot = of_find_node_by_name(nproot, "backlights");
if (!nproot) {
dev_err(&pdev->dev, "failed to find backlights node\n");
return -ENODEV;
}
for_each_child_of_node(nproot, np) {
if (!of_node_cmp(np->name, name)) {
of_property_read_u32(np, "marvell,88pm860x-iset",
&iset);
data->iset = PM8606_WLED_CURRENT(iset);
of_property_read_u32(np, "marvell,88pm860x-pwm",
&data->pwm);
break;
}
}
of_node_put(nproot);
return 0;
}
#else
#define pm860x_backlight_dt_init(x, y, z) (-1)
#endif
static int pm860x_backlight_probe(struct platform_device *pdev)
{
struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
struct pm860x_backlight_pdata *pdata = dev_get_platdata(&pdev->dev);
struct pm860x_backlight_data *data;
struct backlight_device *bl;
struct resource *res;
struct backlight_properties props;
char name[MFD_NAME_SIZE];
int ret = 0;
data = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_backlight_data),
GFP_KERNEL);
if (data == NULL)
return -ENOMEM;
res = platform_get_resource_byname(pdev, IORESOURCE_REG, "duty cycle");
if (!res) {
dev_err(&pdev->dev, "No REG resource for duty cycle\n");
return -ENXIO;
}
data->reg_duty_cycle = res->start;
res = platform_get_resource_byname(pdev, IORESOURCE_REG, "always on");
if (!res) {
dev_err(&pdev->dev, "No REG resource for always on\n");
return -ENXIO;
}
data->reg_always_on = res->start;
res = platform_get_resource_byname(pdev, IORESOURCE_REG, "current");
if (!res) {
dev_err(&pdev->dev, "No REG resource for current\n");
return -ENXIO;
}
data->reg_current = res->start;
memset(name, 0, MFD_NAME_SIZE);
sprintf(name, "backlight-%d", pdev->id);
data->port = pdev->id;
data->chip = chip;
data->i2c = (chip->id == CHIP_PM8606) ? chip->client : chip->companion;
data->current_brightness = MAX_BRIGHTNESS;
if (pm860x_backlight_dt_init(pdev, data, name)) {
if (pdata) {
data->pwm = pdata->pwm;
data->iset = pdata->iset;
}
}
memset(&props, 0, sizeof(struct backlight_properties));
props.type = BACKLIGHT_RAW;
props.max_brightness = MAX_BRIGHTNESS;
bl = devm_backlight_device_register(&pdev->dev, name, &pdev->dev, data,
&pm860x_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);
/* read current backlight */
ret = pm860x_backlight_get_brightness(bl);
if (ret < 0)
return ret;
backlight_update_status(bl);
return 0;
}
static struct platform_driver pm860x_backlight_driver = {
.driver = {
.name = "88pm860x-backlight",
},
.probe = pm860x_backlight_probe,
};
module_platform_driver(pm860x_backlight_driver);
MODULE_DESCRIPTION("Backlight Driver for Marvell Semiconductor 88PM8606");
MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:88pm860x-backlight");
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