/*
* 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/platform_device.h>
#include <linux/fb.h>
#include <linux/i2c.h>
#include <linux/backlight.h>
#include <linux/mfd/88pm860x.h>
#define MAX_BRIGHTNESS (0xFF)
#define MIN_BRIGHTNESS (0)
#define CURRENT_MASK (0x1F << 1)
struct pm860x_backlight_data {
struct pm860x_chip *chip;
struct i2c_client *i2c;
int current_brightness;
int port;
int pwm;
int iset;
};
static inline int wled_a(int port)
{
int ret;
ret = ((port - PM8606_BACKLIGHT1) << 1) + 2;
return ret;
}
static inline int wled_b(int port)
{
int ret;
ret = ((port - PM8606_BACKLIGHT1) << 1) + 3;
return ret;
}
/* WLED2 & WLED3 share the same IDC */
static inline int wled_idc(int port)
{
int ret;
switch (port) {
case PM8606_BACKLIGHT1:
case PM8606_BACKLIGHT2:
ret = ((port - PM8606_BACKLIGHT1) << 1) + 3;
break;
case PM8606_BACKLIGHT3:
default:
ret = ((port - PM8606_BACKLIGHT2) << 1) + 3;
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;
ret = pm860x_reg_write(data->i2c, wled_a(data->port), value);
if (ret < 0)
goto out;
if ((data->current_brightness == 0) && brightness) {
if (data->iset) {
ret = pm860x_set_bits(data->i2c, wled_idc(data->port),
CURRENT_MASK, 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, wled_b(data->port),
PM8606_WLED_ON, PM8606_WLED_ON);
}
} else {
if (brightness == MAX_BRIGHTNESS) {
/* set WLED_ON bit as 100% */
ret = pm860x_set_bits(data->i2c, wled_b(data->port),
PM8606_WLED_ON, PM8606_WLED_ON);
} else {
/* clear WLED_ON bit since it's not 100% */
ret = pm860x_set_bits(data->i2c, wled_b(data->port),
PM8606_WLED_ON, 0);
}
}
if (ret < 0)
goto out;
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, wled_a(data->port));
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 struct backlight_ops pm860x_backlight_ops = {
.options = BL_CORE_SUSPENDRESUME,
.update_status = pm860x_backlight_update_status,
.get_brightness = pm860x_backlight_get_brightness,
};
static int __check_device(struct pm860x_backlight_pdata *pdata, char *name)
{
struct pm860x_backlight_pdata *p = pdata;
int ret = -EINVAL;
while (p && p->id) {
if ((p->id != PM8606_ID_BACKLIGHT) || (p->flags < 0))
break;
if (!strncmp(name, pm860x_backlight_name[p->flags],
MFD_NAME_SIZE)) {
ret = (int)p->flags;
break;
}
p++;
}
return ret;
}
static int pm860x_backlight_probe(struct platform_device *pdev)
{
struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
struct pm860x_platform_data *pm860x_pdata;
struct pm860x_backlight_pdata *pdata = NULL;
struct pm860x_backlight_data *data;
struct backlight_device *bl;
struct resource *res;
struct backlight_properties props;
unsigned char value;
char name[MFD_NAME_SIZE];
int ret;
res = platform_get_resource(pdev, IORESOURCE_IO, 0);
if (res == NULL) {
dev_err(&pdev->dev, "No I/O resource!\n");
return -EINVAL;
}
if (pdev->dev.parent->platform_data) {
pm860x_pdata = pdev->dev.parent->platform_data;
pdata = pm860x_pdata->backlight;
}
if (pdata == NULL) {
dev_err(&pdev->dev, "platform data isn't assigned to "
"backlight\n");
return -EINVAL;
}
data = kzalloc(sizeof(struct pm860x_backlight_data), GFP_KERNEL);
if (data == NULL)
return -ENOMEM;
strncpy(name, res->name, MFD_NAME_SIZE);
data->chip = chip;
data->i2c = (chip->id == CHIP_PM8606) ? chip->client \
: chip->companion;
data->current_brightness = MAX_BRIGHTNESS;
data->pwm = pdata->pwm;
data->iset = pdata->iset;
data->port = __check_device(pdata, name);
if (data->port < 0) {
dev_err(&pdev->dev, "wrong platform data is assigned");
return -EINVAL;
}
memset(&props, 0, sizeof(struct backlight_properties));
props.max_brightness = MAX_BRIGHTNESS;
bl = backlight_device_register(name, &pdev->dev, data,
&pm860x_backlight_ops, &props);
if (IS_ERR(bl)) {
dev_err(&pdev->dev, "failed to register backlight\n");
kfree(data);
return PTR_ERR(bl);
}
bl->props.brightness = MAX_BRIGHTNESS;
platform_set_drvdata(pdev, bl);
/* Enable reference VSYS */
ret = pm860x_reg_read(data->i2c, PM8606_VSYS);
if (ret < 0)
goto out;
if ((ret & PM8606_VSYS_EN) == 0) {
value = ret | PM8606_VSYS_EN;
ret = pm860x_reg_write(data->i2c, PM8606_VSYS, value);
if (ret < 0)
goto out;
}
/* Enable reference OSC */
ret = pm860x_reg_read(data->i2c, PM8606_MISC);
if (ret < 0)
goto out;
if ((ret & PM8606_MISC_OSC_EN) == 0) {
value = ret | PM8606_MISC_OSC_EN;
ret = pm860x_reg_write(data->i2c, PM8606_MISC, value);
if (ret < 0)
goto out;
}
/* read current backlight */
ret = pm860x_backlight_get_brightness(bl);
if (ret < 0)
goto out;
backlight_update_status(bl);
return 0;
out:
kfree(data);
return ret;
}
static int pm860x_backlight_remove(struct platform_device *pdev)
{
struct backlight_device *bl = platform_get_drvdata(pdev);
struct pm860x_backlight_data *data = bl_get_data(bl);
backlight_device_unregister(bl);
kfree(data);
return 0;
}
static struct platform_driver pm860x_backlight_driver = {
.driver = {
.name = "88pm860x-backlight",
.owner = THIS_MODULE,
},
.probe = pm860x_backlight_probe,
.remove = pm860x_backlight_remove,
};
static int __init pm860x_backlight_init(void)
{
return platform_driver_register(&pm860x_backlight_driver);
}
module_init(pm860x_backlight_init);
static void __exit pm860x_backlight_exit(void)
{
platform_driver_unregister(&pm860x_backlight_driver);
}
module_exit(pm860x_backlight_exit);
MODULE_DESCRIPTION("Backlight Driver for Marvell Semiconductor 88PM8606");
MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:88pm860x-backlight");
