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pwm-backlight: switch to gpiod interface 

Switch to the new gpiod interface, which allows to handle GPIO
properties such as active low transparently and removes a whole bunch of
code.

There are still a couple of users of this driver that rely on passing
the enable GPIO number through platform data, so a fallback mechanism
using a GPIO number is still available to avoid breaking them. It will
be removed once current users have switched to the GPIO lookup tables
provided by the gpiod interface.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
This commit is contained in:
Alexandre Courbot 2014-02-27 14:53:34 +09:00 committed by Thierry Reding
parent a4406f165f
commit 257462dbf3
2 changed files with 30 additions and 44 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

69
drivers/video/backlight/pwm_bl.c
View File

@ -10,8 +10,8 @@
* published by the Free Software Foundation.
*/
#include <linux/gpio/consumer.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
@ -32,8 +32,7 @@ struct pwm_bl_data {
unsigned int *levels;
bool enabled;
struct regulator *power_supply;
int enable_gpio;
unsigned long enable_gpio_flags;
struct gpio_desc *enable_gpio;
unsigned int scale;
int (*notify)(struct device *,
int brightness);
@ -54,12 +53,8 @@ static void pwm_backlight_power_on(struct pwm_bl_data *pb, int brightness)
if (err < 0)
dev_err(pb->dev, "failed to enable power supply\n");
if (gpio_is_valid(pb->enable_gpio)) {
if (pb->enable_gpio_flags & PWM_BACKLIGHT_GPIO_ACTIVE_LOW)
gpio_set_value(pb->enable_gpio, 0);
else
gpio_set_value(pb->enable_gpio, 1);
}
if (pb->enable_gpio)
gpiod_set_value(pb->enable_gpio, 1);
pwm_enable(pb->pwm);
pb->enabled = true;
@ -73,12 +68,8 @@ static void pwm_backlight_power_off(struct pwm_bl_data *pb)
pwm_config(pb->pwm, 0, pb->period);
pwm_disable(pb->pwm);
if (gpio_is_valid(pb->enable_gpio)) {
if (pb->enable_gpio_flags & PWM_BACKLIGHT_GPIO_ACTIVE_LOW)
gpio_set_value(pb->enable_gpio, 1);
else
gpio_set_value(pb->enable_gpio, 0);
}
if (pb->enable_gpio)
gpiod_set_value(pb->enable_gpio, 0);
regulator_disable(pb->power_supply);
pb->enabled = false;
@ -148,7 +139,6 @@ static int pwm_backlight_parse_dt(struct device *dev,
struct platform_pwm_backlight_data *data)
{
struct device_node *node = dev->of_node;
enum of_gpio_flags flags;
struct property *prop;
int length;
u32 value;
@ -189,14 +179,6 @@ static int pwm_backlight_parse_dt(struct device *dev,
data->max_brightness--;
}
data->enable_gpio = of_get_named_gpio_flags(node, "enable-gpios", 0,
&flags);
if (data->enable_gpio == -EPROBE_DEFER)
return -EPROBE_DEFER;
if (gpio_is_valid(data->enable_gpio) && (flags & OF_GPIO_ACTIVE_LOW))
data->enable_gpio_flags |= PWM_BACKLIGHT_GPIO_ACTIVE_LOW;
return 0;
}
@ -256,8 +238,6 @@ static int pwm_backlight_probe(struct platform_device *pdev)
} else
pb->scale = data->max_brightness;
pb->enable_gpio = data->enable_gpio;
pb->enable_gpio_flags = data->enable_gpio_flags;
pb->notify = data->notify;
pb->notify_after = data->notify_after;
pb->check_fb = data->check_fb;
@ -265,26 +245,38 @@ static int pwm_backlight_probe(struct platform_device *pdev)
pb->dev = &pdev->dev;
pb->enabled = false;
if (gpio_is_valid(pb->enable_gpio)) {
unsigned long flags;
if (pb->enable_gpio_flags & PWM_BACKLIGHT_GPIO_ACTIVE_LOW)
flags = GPIOF_OUT_INIT_HIGH;
pb->enable_gpio = devm_gpiod_get(&pdev->dev, "enable");
if (IS_ERR(pb->enable_gpio)) {
ret = PTR_ERR(pb->enable_gpio);
if (ret == -ENOENT)
pb->enable_gpio = NULL;
else
flags = GPIOF_OUT_INIT_LOW;
goto err_alloc;
}
ret = gpio_request_one(pb->enable_gpio, flags, "enable");
/*
* Compatibility fallback for drivers still using the integer GPIO
* platform data. Must go away soon.
*/
if (!pb->enable_gpio && gpio_is_valid(data->enable_gpio)) {
ret = devm_gpio_request_one(&pdev->dev, data->enable_gpio,
GPIOF_OUT_INIT_HIGH, "enable");
if (ret < 0) {
dev_err(&pdev->dev, "failed to request GPIO#%d: %d\n",
pb->enable_gpio, ret);
data->enable_gpio, ret);
goto err_alloc;
}
pb->enable_gpio = gpio_to_desc(data->enable_gpio);
}
if (pb->enable_gpio)
gpiod_direction_output(pb->enable_gpio, 1);
pb->power_supply = devm_regulator_get(&pdev->dev, "power");
if (IS_ERR(pb->power_supply)) {
ret = PTR_ERR(pb->power_supply);
goto err_gpio;
goto err_alloc;
}
pb->pwm = devm_pwm_get(&pdev->dev, NULL);
@ -295,7 +287,7 @@ static int pwm_backlight_probe(struct platform_device *pdev)
if (IS_ERR(pb->pwm)) {
dev_err(&pdev->dev, "unable to request legacy PWM\n");
ret = PTR_ERR(pb->pwm);
goto err_gpio;
goto err_alloc;
}
}
@ -320,7 +312,7 @@ static int pwm_backlight_probe(struct platform_device *pdev)
if (IS_ERR(bl)) {
dev_err(&pdev->dev, "failed to register backlight\n");
ret = PTR_ERR(bl);
goto err_gpio;
goto err_alloc;
}
if (data->dft_brightness > data->max_brightness) {
@ -336,9 +328,6 @@ static int pwm_backlight_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, bl);
return 0;
err_gpio:
if (gpio_is_valid(pb->enable_gpio))
gpio_free(pb->enable_gpio);
err_alloc:
if (data->exit)
data->exit(&pdev->dev);

5
include/linux/pwm_backlight.h
View File

@ -6,9 +6,6 @@
#include <linux/backlight.h>
/* TODO: convert to gpiod_*() API once it has been merged */
#define PWM_BACKLIGHT_GPIO_ACTIVE_LOW (1 << 0)
struct platform_pwm_backlight_data {
int pwm_id;
unsigned int max_brightness;
@ -16,8 +13,8 @@ struct platform_pwm_backlight_data {
unsigned int lth_brightness;
unsigned int pwm_period_ns;
unsigned int *levels;
/* TODO remove once all users are switched to gpiod_* API */
int enable_gpio;
unsigned long enable_gpio_flags;
int (*init)(struct device *dev);
int (*notify)(struct device *dev, int brightness);
void (*notify_after)(struct device *dev, int brightness);