327 lines
7.5 KiB
C
327 lines
7.5 KiB
C
|
// SPDX-License-Identifier: GPL-2.0-only
|
||
|
|
/*
|
||
|
|
* TI LP8788 MFD - backlight driver
|
||
|
|
*
|
||
|
|
* Copyright 2012 Texas Instruments
|
||
|
|
*
|
||
|
|
* Author: Milo(Woogyom) Kim <milo.kim@ti.com>
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/backlight.h>
|
||
|
|
#include <linux/err.h>
|
||
|
|
#include <linux/mfd/lp8788.h>
|
||
|
|
#include <linux/module.h>
|
||
|
|
#include <linux/platform_device.h>
|
||
|
|
#include <linux/pwm.h>
|
||
|
|
#include <linux/slab.h>
|
||
|
|
|
||
|
|
/* Register address */
|
||
|
|
#define LP8788_BL_CONFIG 0x96
|
||
|
|
#define LP8788_BL_EN BIT(0)
|
||
|
|
#define LP8788_BL_PWM_INPUT_EN BIT(5)
|
||
|
|
#define LP8788_BL_FULLSCALE_SHIFT 2
|
||
|
|
#define LP8788_BL_DIM_MODE_SHIFT 1
|
||
|
|
#define LP8788_BL_PWM_POLARITY_SHIFT 6
|
||
|
|
|
||
|
|
#define LP8788_BL_BRIGHTNESS 0x97
|
||
|
|
|
||
|
|
#define LP8788_BL_RAMP 0x98
|
||
|
|
#define LP8788_BL_RAMP_RISE_SHIFT 4
|
||
|
|
|
||
|
|
#define MAX_BRIGHTNESS 127
|
||
|
|
#define DEFAULT_BL_NAME "lcd-backlight"
|
||
|
|
|
||
|
|
struct lp8788_bl_config {
|
||
|
|
enum lp8788_bl_ctrl_mode bl_mode;
|
||
|
|
enum lp8788_bl_dim_mode dim_mode;
|
||
|
|
enum lp8788_bl_full_scale_current full_scale;
|
||
|
|
enum lp8788_bl_ramp_step rise_time;
|
||
|
|
enum lp8788_bl_ramp_step fall_time;
|
||
|
|
enum pwm_polarity pwm_pol;
|
||
|
|
};
|
||
|
|
|
||
|
|
struct lp8788_bl {
|
||
|
|
struct lp8788 *lp;
|
||
|
|
struct backlight_device *bl_dev;
|
||
|
|
struct lp8788_backlight_platform_data *pdata;
|
||
|
|
enum lp8788_bl_ctrl_mode mode;
|
||
|
|
struct pwm_device *pwm;
|
||
|
|
};
|
||
|
|
|
||
|
|
static struct lp8788_bl_config default_bl_config = {
|
||
|
|
.bl_mode = LP8788_BL_REGISTER_ONLY,
|
||
|
|
.dim_mode = LP8788_DIM_EXPONENTIAL,
|
||
|
|
.full_scale = LP8788_FULLSCALE_1900uA,
|
||
|
|
.rise_time = LP8788_RAMP_8192us,
|
||
|
|
.fall_time = LP8788_RAMP_8192us,
|
||
|
|
.pwm_pol = PWM_POLARITY_NORMAL,
|
||
|
|
};
|
||
|
|
|
||
|
|
static inline bool is_brightness_ctrl_by_pwm(enum lp8788_bl_ctrl_mode mode)
|
||
|
|
{
|
||
|
|
return mode == LP8788_BL_COMB_PWM_BASED;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline bool is_brightness_ctrl_by_register(enum lp8788_bl_ctrl_mode mode)
|
||
|
|
{
|
||
|
|
return mode == LP8788_BL_REGISTER_ONLY ||
|
||
|
|
mode == LP8788_BL_COMB_REGISTER_BASED;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int lp8788_backlight_configure(struct lp8788_bl *bl)
|
||
|
|
{
|
||
|
|
struct lp8788_backlight_platform_data *pdata = bl->pdata;
|
||
|
|
struct lp8788_bl_config *cfg = &default_bl_config;
|
||
|
|
int ret;
|
||
|
|
u8 val;
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Update chip configuration if platform data exists,
|
||
|
|
* otherwise use the default settings.
|
||
|
|
*/
|
||
|
|
if (pdata) {
|
||
|
|
cfg->bl_mode = pdata->bl_mode;
|
||
|
|
cfg->dim_mode = pdata->dim_mode;
|
||
|
|
cfg->full_scale = pdata->full_scale;
|
||
|
|
cfg->rise_time = pdata->rise_time;
|
||
|
|
cfg->fall_time = pdata->fall_time;
|
||
|
|
cfg->pwm_pol = pdata->pwm_pol;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Brightness ramp up/down */
|
||
|
|
val = (cfg->rise_time << LP8788_BL_RAMP_RISE_SHIFT) | cfg->fall_time;
|
||
|
|
ret = lp8788_write_byte(bl->lp, LP8788_BL_RAMP, val);
|
||
|
|
if (ret)
|
||
|
|
return ret;
|
||
|
|
|
||
|
|
/* Fullscale current setting */
|
||
|
|
val = (cfg->full_scale << LP8788_BL_FULLSCALE_SHIFT) |
|
||
|
|
(cfg->dim_mode << LP8788_BL_DIM_MODE_SHIFT);
|
||
|
|
|
||
|
|
/* Brightness control mode */
|
||
|
|
switch (cfg->bl_mode) {
|
||
|
|
case LP8788_BL_REGISTER_ONLY:
|
||
|
|
val |= LP8788_BL_EN;
|
||
|
|
break;
|
||
|
|
case LP8788_BL_COMB_PWM_BASED:
|
||
|
|
case LP8788_BL_COMB_REGISTER_BASED:
|
||
|
|
val |= LP8788_BL_EN | LP8788_BL_PWM_INPUT_EN |
|
||
|
|
(cfg->pwm_pol << LP8788_BL_PWM_POLARITY_SHIFT);
|
||
|
|
break;
|
||
|
|
default:
|
||
|
|
dev_err(bl->lp->dev, "invalid mode: %d\n", cfg->bl_mode);
|
||
|
|
return -EINVAL;
|
||
|
|
}
|
||
|
|
|
||
|
|
bl->mode = cfg->bl_mode;
|
||
|
|
|
||
|
|
return lp8788_write_byte(bl->lp, LP8788_BL_CONFIG, val);
|
||
|
|
}
|
||
|
|
|
||
|
|
static void lp8788_pwm_ctrl(struct lp8788_bl *bl, int br, int max_br)
|
||
|
|
{
|
||
|
|
unsigned int period;
|
||
|
|
unsigned int duty;
|
||
|
|
struct device *dev;
|
||
|
|
struct pwm_device *pwm;
|
||
|
|
|
||
|
|
if (!bl->pdata)
|
||
|
|
return;
|
||
|
|
|
||
|
|
period = bl->pdata->period_ns;
|
||
|
|
duty = br * period / max_br;
|
||
|
|
dev = bl->lp->dev;
|
||
|
|
|
||
|
|
/* request PWM device with the consumer name */
|
||
|
|
if (!bl->pwm) {
|
||
|
|
pwm = devm_pwm_get(dev, LP8788_DEV_BACKLIGHT);
|
||
|
|
if (IS_ERR(pwm)) {
|
||
|
|
dev_err(dev, "can not get PWM device\n");
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
bl->pwm = pwm;
|
||
|
|
|
||
|
|
/*
|
||
|
|
* FIXME: pwm_apply_args() should be removed when switching to
|
||
|
|
* the atomic PWM API.
|
||
|
|
*/
|
||
|
|
pwm_apply_args(pwm);
|
||
|
|
}
|
||
|
|
|
||
|
|
pwm_config(bl->pwm, duty, period);
|
||
|
|
if (duty)
|
||
|
|
pwm_enable(bl->pwm);
|
||
|
|
else
|
||
|
|
pwm_disable(bl->pwm);
|
||
|
|
}
|
||
|
|
|
||
|
|
static int lp8788_bl_update_status(struct backlight_device *bl_dev)
|
||
|
|
{
|
||
|
|
struct lp8788_bl *bl = bl_get_data(bl_dev);
|
||
|
|
enum lp8788_bl_ctrl_mode mode = bl->mode;
|
||
|
|
|
||
|
|
if (bl_dev->props.state & BL_CORE_SUSPENDED)
|
||
|
|
bl_dev->props.brightness = 0;
|
||
|
|
|
||
|
|
if (is_brightness_ctrl_by_pwm(mode)) {
|
||
|
|
int brt = bl_dev->props.brightness;
|
||
|
|
int max = bl_dev->props.max_brightness;
|
||
|
|
|
||
|
|
lp8788_pwm_ctrl(bl, brt, max);
|
||
|
|
} else if (is_brightness_ctrl_by_register(mode)) {
|
||
|
|
u8 brt = bl_dev->props.brightness;
|
||
|
|
|
||
|
|
lp8788_write_byte(bl->lp, LP8788_BL_BRIGHTNESS, brt);
|
||
|
|
}
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static const struct backlight_ops lp8788_bl_ops = {
|
||
|
|
.options = BL_CORE_SUSPENDRESUME,
|
||
|
|
.update_status = lp8788_bl_update_status,
|
||
|
|
};
|
||
|
|
|
||
|
|
static int lp8788_backlight_register(struct lp8788_bl *bl)
|
||
|
|
{
|
||
|
|
struct backlight_device *bl_dev;
|
||
|
|
struct backlight_properties props;
|
||
|
|
struct lp8788_backlight_platform_data *pdata = bl->pdata;
|
||
|
|
int init_brt;
|
||
|
|
char *name;
|
||
|
|
|
||
|
|
props.type = BACKLIGHT_PLATFORM;
|
||
|
|
props.max_brightness = MAX_BRIGHTNESS;
|
||
|
|
|
||
|
|
/* Initial brightness */
|
||
|
|
if (pdata)
|
||
|
|
init_brt = min_t(int, pdata->initial_brightness,
|
||
|
|
props.max_brightness);
|
||
|
|
else
|
||
|
|
init_brt = 0;
|
||
|
|
|
||
|
|
props.brightness = init_brt;
|
||
|
|
|
||
|
|
/* Backlight device name */
|
||
|
|
if (!pdata || !pdata->name)
|
||
|
|
name = DEFAULT_BL_NAME;
|
||
|
|
else
|
||
|
|
name = pdata->name;
|
||
|
|
|
||
|
|
bl_dev = backlight_device_register(name, bl->lp->dev, bl,
|
||
|
|
&lp8788_bl_ops, &props);
|
||
|
|
if (IS_ERR(bl_dev))
|
||
|
|
return PTR_ERR(bl_dev);
|
||
|
|
|
||
|
|
bl->bl_dev = bl_dev;
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void lp8788_backlight_unregister(struct lp8788_bl *bl)
|
||
|
|
{
|
||
|
|
struct backlight_device *bl_dev = bl->bl_dev;
|
||
|
|
|
||
|
|
backlight_device_unregister(bl_dev);
|
||
|
|
}
|
||
|
|
|
||
|
|
static ssize_t lp8788_get_bl_ctl_mode(struct device *dev,
|
||
|
|
struct device_attribute *attr, char *buf)
|
||
|
|
{
|
||
|
|
struct lp8788_bl *bl = dev_get_drvdata(dev);
|
||
|
|
enum lp8788_bl_ctrl_mode mode = bl->mode;
|
||
|
|
char *strmode;
|
||
|
|
|
||
|
|
if (is_brightness_ctrl_by_pwm(mode))
|
||
|
|
strmode = "PWM based";
|
||
|
|
else if (is_brightness_ctrl_by_register(mode))
|
||
|
|
strmode = "Register based";
|
||
|
|
else
|
||
|
|
strmode = "Invalid mode";
|
||
|
|
|
||
|
|
return scnprintf(buf, PAGE_SIZE, "%s\n", strmode);
|
||
|
|
}
|
||
|
|
|
||
|
|
static DEVICE_ATTR(bl_ctl_mode, S_IRUGO, lp8788_get_bl_ctl_mode, NULL);
|
||
|
|
|
||
|
|
static struct attribute *lp8788_attributes[] = {
|
||
|
|
&dev_attr_bl_ctl_mode.attr,
|
||
|
|
NULL,
|
||
|
|
};
|
||
|
|
|
||
|
|
static const struct attribute_group lp8788_attr_group = {
|
||
|
|
.attrs = lp8788_attributes,
|
||
|
|
};
|
||
|
|
|
||
|
|
static int lp8788_backlight_probe(struct platform_device *pdev)
|
||
|
|
{
|
||
|
|
struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent);
|
||
|
|
struct lp8788_bl *bl;
|
||
|
|
int ret;
|
||
|
|
|
||
|
|
bl = devm_kzalloc(lp->dev, sizeof(struct lp8788_bl), GFP_KERNEL);
|
||
|
|
if (!bl)
|
||
|
|
return -ENOMEM;
|
||
|
|
|
||
|
|
bl->lp = lp;
|
||
|
|
if (lp->pdata)
|
||
|
|
bl->pdata = lp->pdata->bl_pdata;
|
||
|
|
|
||
|
|
platform_set_drvdata(pdev, bl);
|
||
|
|
|
||
|
|
ret = lp8788_backlight_configure(bl);
|
||
|
|
if (ret) {
|
||
|
|
dev_err(lp->dev, "backlight config err: %d\n", ret);
|
||
|
|
goto err_dev;
|
||
|
|
}
|
||
|
|
|
||
|
|
ret = lp8788_backlight_register(bl);
|
||
|
|
if (ret) {
|
||
|
|
dev_err(lp->dev, "register backlight err: %d\n", ret);
|
||
|
|
goto err_dev;
|
||
|
|
}
|
||
|
|
|
||
|
|
ret = sysfs_create_group(&pdev->dev.kobj, &lp8788_attr_group);
|
||
|
|
if (ret) {
|
||
|
|
dev_err(lp->dev, "register sysfs err: %d\n", ret);
|
||
|
|
goto err_sysfs;
|
||
|
|
}
|
||
|
|
|
||
|
|
backlight_update_status(bl->bl_dev);
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
err_sysfs:
|
||
|
|
lp8788_backlight_unregister(bl);
|
||
|
|
err_dev:
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int lp8788_backlight_remove(struct platform_device *pdev)
|
||
|
|
{
|
||
|
|
struct lp8788_bl *bl = platform_get_drvdata(pdev);
|
||
|
|
struct backlight_device *bl_dev = bl->bl_dev;
|
||
|
|
|
||
|
|
bl_dev->props.brightness = 0;
|
||
|
|
backlight_update_status(bl_dev);
|
||
|
|
sysfs_remove_group(&pdev->dev.kobj, &lp8788_attr_group);
|
||
|
|
lp8788_backlight_unregister(bl);
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static struct platform_driver lp8788_bl_driver = {
|
||
|
|
.probe = lp8788_backlight_probe,
|
||
|
|
.remove = lp8788_backlight_remove,
|
||
|
|
.driver = {
|
||
|
|
.name = LP8788_DEV_BACKLIGHT,
|
||
|
|
},
|
||
|
|
};
|
||
|
|
module_platform_driver(lp8788_bl_driver);
|
||
|
|
|
||
|
|
MODULE_DESCRIPTION("Texas Instruments LP8788 Backlight Driver");
|
||
|
|
MODULE_AUTHOR("Milo Kim");
|
||
|
|
MODULE_LICENSE("GPL");
|
||
|
|
MODULE_ALIAS("platform:lp8788-backlight");
|