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/*
* Copyright (c) 2013, NVIDIA CORPORATION. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
*/
#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/regulator/consumer.h>
#include <linux/lm3528.h>
#include <linux/regmap.h>
#define LM3528_BL_MAX_CURR 0x7F
/* I2C registers */
#define LM3528_GP 0x10
#define LM3528_GP_ENM (1 << 0)
#define LM3528_GP_ENS (1 << 1)
#define LM3528_GP_UNI (1 << 2)
#define LM3528_GP_RMP0 (1 << 3)
#define LM3528_GP_RMP1 (1 << 4)
#define LM3528_GP_OLED (1 << 5)
#define LM3528_BMAIN 0xA0
#define LM3528_BSUB 0xB0
#define LM3528_HPG 0x80
#define LM3528_GPIO 0x81
#define LM3528_PGEN0 0x90
#define LM3528_PGEN1 0x91
#define LM3528_PGEN2 0x92
#define LM3528_PGEN3 0x93
struct lm3528_backlight_data {
struct device *lm3528_dev;
struct regmap *regmap;
struct i2c_client *client;
struct regulator *regulator;
struct backlight_device *bl;
bool (*is_powered)(void);
int (*notify)(struct device *dev, int brightness);
int current_brightness;
};
enum chips { lm3528 };
static const struct i2c_device_id lm3528_id[] = {
{ "lm3528_display_bl", lm3528 },
{},
};
MODULE_DEVICE_TABLE(i2c, lm3528_id);
static const struct regmap_config lm3528_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
};
static int lm3528_backlight_set(struct backlight_device *bl, int brightness)
{
struct lm3528_backlight_data *data = bl_get_data(bl);
if (data->is_powered)
if (!data->is_powered()) {
pr_err("%s skipped as panel is not powered\n",
__func__);
/* do not report error else suspend fails */
return 0;
}
if (data->notify)
brightness = data->notify(data->lm3528_dev, brightness);
data->current_brightness = brightness;
/* normalize the brightness value [0-255] to lm3528 range */
brightness = brightness * LM3528_BL_MAX_CURR / 255;
regmap_update_bits(data->regmap, LM3528_GP,
LM3528_GP_ENM | LM3528_GP_UNI,
LM3528_GP_ENM | LM3528_GP_UNI);
return regmap_write(data->regmap, LM3528_BMAIN, brightness);
}
static int lm3528_backlight_update_status(struct backlight_device *bl)
{
int brightness = bl->props.brightness;
return lm3528_backlight_set(bl, brightness);
}
static int lm3528_backlight_get_brightness(struct backlight_device *bl)
{
struct lm3528_backlight_data *data = bl_get_data(bl);
return data->current_brightness;
}
static const struct backlight_ops lm3528_backlight_ops = {
.update_status = lm3528_backlight_update_status,
.get_brightness = lm3528_backlight_get_brightness,
};
static int lm3528_bl_probe(struct i2c_client *i2c,
const struct i2c_device_id *id)
{
struct lm3528_backlight_data *data;
struct backlight_device *bl;
struct backlight_properties props;
struct lm3528_platform_data *pData = i2c->dev.platform_data;
int ret;
data = devm_kzalloc(&i2c->dev, sizeof(*data), GFP_KERNEL);
if (data == NULL)
return -ENOMEM;
data->client = i2c;
data->lm3528_dev = &i2c->dev;
data->current_brightness = 0;
data->notify = pData->notify;
data->is_powered = pData->is_powered;
data->regulator = regulator_get(data->lm3528_dev, "vin");
if (IS_ERR(data->regulator)) {
dev_err(&i2c->dev, "%s: failed to get regulator\n", __func__);
data->regulator = NULL;
} else {
regulator_enable(data->regulator);
}
data->regmap = devm_regmap_init_i2c(i2c, &lm3528_regmap_config);
if (IS_ERR(data->regmap)) {
ret = PTR_ERR(data->regmap);
dev_err(&i2c->dev, "regmap init failed: %d\n", ret);
return ret;
}
props.type = BACKLIGHT_RAW;
props.max_brightness = 255;
bl = backlight_device_register(i2c->name, data->lm3528_dev, data,
&lm3528_backlight_ops, &props);
if (IS_ERR(bl)) {
dev_err(&i2c->dev, "failed to register backlight\n");
return PTR_ERR(bl);
}
data->bl = bl;
bl->props.brightness = pData->dft_brightness;
i2c_set_clientdata(i2c, data);
backlight_update_status(bl);
return 0;
}
static int lm3528_bl_remove(struct i2c_client *cl)
{
struct lm3528_backlight_data *data = i2c_get_clientdata(cl);
data->bl->props.brightness = 0;
backlight_update_status(data->bl);
backlight_device_unregister(data->bl);
return 0;
}
#ifdef CONFIG_PM
static int lm3528_bl_suspend(struct device *dev)
{
struct i2c_client *i2c = to_i2c_client(dev);
struct lm3528_backlight_data *data = i2c_get_clientdata(i2c);
struct backlight_device *bl = data->bl;
return lm3528_backlight_set(bl, 0);
}
static int lm3528_bl_resume(struct device *dev)
{
struct i2c_client *i2c = to_i2c_client(dev);
struct lm3528_backlight_data *data = i2c_get_clientdata(i2c);
struct backlight_device *bl = data->bl;
backlight_update_status(bl);
return 0;
}
static const struct dev_pm_ops lm3528_bl_pm_ops = {
.suspend = lm3528_bl_suspend,
.resume = lm3528_bl_resume,
};
#endif
static struct i2c_driver lm3528_bl_driver = {
.driver = {
.name = "lm3528_display_bl",
.owner = THIS_MODULE,
#ifdef CONFIG_PM
.pm = &lm3528_bl_pm_ops,
#endif
},
.id_table = lm3528_id,
.probe = lm3528_bl_probe,
.remove = lm3528_bl_remove,
};
module_i2c_driver(lm3528_bl_driver);
MODULE_AUTHOR("Chaitanya Bandi <bandik@nvidia.com>");
MODULE_DESCRIPTION("LM3528 Backlight display driver");
MODULE_LICENSE("GPL v2");
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