[PATCH/RFC v3 5/7] leds: Drivers shouldn't enforce SYNC/ASYNC brightness setting

From: Jacek Anaszewski
Date: Fri Jul 03 2015 - 09:15:05 EST

This patch removes SET_BRIGHTNESS_ASYNC and SET_BRIGHTNESS sync flags.
led_set_brightness now calls led_set_brightness_nosleep rather then
choosing between sync and async op basing on the flags defined by the
driver. Caller can use led_set_brightness_sync API to make sure that
brightness_set op will be called synchronously.

Signed-off-by: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx>
---
drivers/leds/led-class-flash.c | 7 -----
drivers/leds/led-class.c | 2 --
drivers/leds/led-core.c | 17 ++-----------
drivers/leds/leds-aat1290.c | 50 +++++++++---------------------------
drivers/leds/leds-ktd2692.c | 41 ++++--------------------------
drivers/leds/leds-max77693.c | 55 +++++-----------------------------------
include/linux/leds.h | 30 +++++-----------------
7 files changed, 33 insertions(+), 169 deletions(-)

diff --git a/drivers/leds/led-class-flash.c b/drivers/leds/led-class-flash.c
index 3b25734..68c3f36 100644
--- a/drivers/leds/led-class-flash.c
+++ b/drivers/leds/led-class-flash.c
@@ -298,9 +298,6 @@ int led_classdev_flash_register(struct device *parent,
led_cdev = &fled_cdev->led_cdev;

if (led_cdev->flags & LED_DEV_CAP_FLASH) {
- if (!led_cdev->brightness_set_sync)
- return -EINVAL;
-
ops = fled_cdev->ops;
if (!ops || !ops->strobe_set)
return -EINVAL;
@@ -316,10 +313,6 @@ int led_classdev_flash_register(struct device *parent,
if (ret < 0)
return ret;

- /* Setting a torch brightness needs to have immediate effect */
- led_cdev->flags &= ~SET_BRIGHTNESS_ASYNC;
- led_cdev->flags |= SET_BRIGHTNESS_SYNC;
-
return 0;
}
EXPORT_SYMBOL_GPL(led_classdev_flash_register);
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 964750a..d8d7a76 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -280,8 +280,6 @@ int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
if (!led_cdev->max_brightness)
led_cdev->max_brightness = LED_FULL;

- led_cdev->flags |= SET_BRIGHTNESS_ASYNC;
-
led_update_brightness(led_cdev);

INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed);
diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
index 428f04c..5f869fa 100644
--- a/drivers/leds/led-core.c
+++ b/drivers/leds/led-core.c
@@ -118,8 +118,6 @@ EXPORT_SYMBOL_GPL(led_stop_software_blink);
void led_set_brightness(struct led_classdev *led_cdev,
enum led_brightness brightness)
{
- int ret = 0;
-
/*
* In case blinking is on delay brightness setting
* until the next timer tick.
@@ -137,20 +135,9 @@ void led_set_brightness(struct led_classdev *led_cdev,
*/
led_cdev->flags |= LED_BLINK_DISABLE;
led_set_brightness_async(led_cdev, brightness);
- return;
+ } else {
+ led_set_brightness_nosleep(led_cdev, brightness);
}
-
- if (led_cdev->flags & SET_BRIGHTNESS_ASYNC) {
- led_set_brightness_async(led_cdev, brightness);
- return;
- } else if (led_cdev->flags & SET_BRIGHTNESS_SYNC)
- ret = led_set_brightness_sync(led_cdev, brightness);
- else
- ret = -EINVAL;
-
- if (ret < 0)
- dev_dbg(led_cdev->dev, "Setting LED brightness failed (%d)\n",
- ret);
}
EXPORT_SYMBOL(led_set_brightness);

diff --git a/drivers/leds/leds-aat1290.c b/drivers/leds/leds-aat1290.c
index 1ac525b..318bcf0 100644
--- a/drivers/leds/leds-aat1290.c
+++ b/drivers/leds/leds-aat1290.c
@@ -20,7 +20,6 @@
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
-#include <linux/workqueue.h>
#include <media/v4l2-flash-led-class.h>

#define AAT1290_MOVIE_MODE_CURRENT_ADDR 17
@@ -82,8 +81,6 @@ struct aat1290_led {

/* brightness cache */
unsigned int torch_brightness;
- /* assures led-triggers compatibility */
- struct work_struct work_brightness_set;
};

static struct aat1290_led *fled_cdev_to_led(
@@ -92,6 +89,12 @@ static struct aat1290_led *fled_cdev_to_led(
return container_of(fled_cdev, struct aat1290_led, fled_cdev);
}

+static struct led_classdev_flash *led_cdev_to_fled_cdev(
+ struct led_classdev *led_cdev)
+{
+ return container_of(led_cdev, struct led_classdev_flash, led_cdev);
+}
+
static void aat1290_as2cwire_write(struct aat1290_led *led, int addr, int value)
{
int i;
@@ -134,9 +137,14 @@ static void aat1290_set_flash_safety_timer(struct aat1290_led *led,
flash_tm_reg);
}

-static void aat1290_brightness_set(struct aat1290_led *led,
+/* LED subsystem callbacks */
+
+static void aat1290_led_brightness_set(struct led_classdev *led_cdev,
enum led_brightness brightness)
{
+ struct led_classdev_flash *fled_cdev = led_cdev_to_fled_cdev(led_cdev);
+ struct aat1290_led *led = fled_cdev_to_led(fled_cdev);
+
mutex_lock(&led->lock);

if (brightness == 0) {
@@ -160,37 +168,6 @@ static void aat1290_brightness_set(struct aat1290_led *led,
mutex_unlock(&led->lock);
}

-/* LED subsystem callbacks */
-
-static void aat1290_brightness_set_work(struct work_struct *work)
-{
- struct aat1290_led *led =
- container_of(work, struct aat1290_led, work_brightness_set);
-
- aat1290_brightness_set(led, led->torch_brightness);
-}
-
-static void aat1290_led_brightness_set(struct led_classdev *led_cdev,
- enum led_brightness brightness)
-{
- struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
- struct aat1290_led *led = fled_cdev_to_led(fled_cdev);
-
- led->torch_brightness = brightness;
- schedule_work(&led->work_brightness_set);
-}
-
-static int aat1290_led_brightness_set_sync(struct led_classdev *led_cdev,
- enum led_brightness brightness)
-{
- struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
- struct aat1290_led *led = fled_cdev_to_led(fled_cdev);
-
- aat1290_brightness_set(led, brightness);
-
- return 0;
-}
-
static int aat1290_led_flash_strobe_set(struct led_classdev_flash *fled_cdev,
bool state)

@@ -510,10 +487,8 @@ static int aat1290_led_probe(struct platform_device *pdev)

/* Initialize LED Flash class device */
led_cdev->brightness_set = aat1290_led_brightness_set;
- led_cdev->brightness_set_sync = aat1290_led_brightness_set_sync;
led_cdev->max_brightness = led_cfg.max_brightness;
led_cdev->flags |= LED_DEV_CAP_FLASH;
- INIT_WORK(&led->work_brightness_set, aat1290_brightness_set_work);

aat1290_init_flash_timeout(led, &led_cfg);

@@ -548,7 +523,6 @@ static int aat1290_led_remove(struct platform_device *pdev)

v4l2_flash_release(led->v4l2_flash);
led_classdev_flash_unregister(&led->fled_cdev);
- cancel_work_sync(&led->work_brightness_set);

mutex_destroy(&led->lock);

diff --git a/drivers/leds/leds-ktd2692.c b/drivers/leds/leds-ktd2692.c
index 2ae8c4d..1e92656 100644
--- a/drivers/leds/leds-ktd2692.c
+++ b/drivers/leds/leds-ktd2692.c
@@ -18,7 +18,6 @@
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
-#include <linux/workqueue.h>

/* Value related the movie mode */
#define KTD2692_MOVIE_MODE_CURRENT_LEVELS 16
@@ -82,7 +81,6 @@ struct ktd2692_context {
/* secures access to the device */
struct mutex lock;
struct regulator *regulator;
- struct work_struct work_brightness_set;

struct gpio_desc *aux_gpio;
struct gpio_desc *ctrl_gpio;
@@ -158,9 +156,12 @@ static void ktd2692_expresswire_write(struct ktd2692_context *led, u8 value)
ktd2692_expresswire_end(led);
}

-static void ktd2692_brightness_set(struct ktd2692_context *led,
- enum led_brightness brightness)
+static void ktd2692_led_brightness_set(struct led_classdev *led_cdev,
+ enum led_brightness brightness)
{
+ struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
+ struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
+
mutex_lock(&led->lock);

if (brightness == LED_OFF) {
@@ -176,35 +177,6 @@ static void ktd2692_brightness_set(struct ktd2692_context *led,
mutex_unlock(&led->lock);
}

-static void ktd2692_brightness_set_work(struct work_struct *work)
-{
- struct ktd2692_context *led =
- container_of(work, struct ktd2692_context, work_brightness_set);
-
- ktd2692_brightness_set(led, led->torch_brightness);
-}
-
-static void ktd2692_led_brightness_set(struct led_classdev *led_cdev,
- enum led_brightness brightness)
-{
- struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
- struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
-
- led->torch_brightness = brightness;
- schedule_work(&led->work_brightness_set);
-}
-
-static int ktd2692_led_brightness_set_sync(struct led_classdev *led_cdev,
- enum led_brightness brightness)
-{
- struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
- struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
-
- ktd2692_brightness_set(led, brightness);
-
- return 0;
-}
-
static int ktd2692_led_flash_strobe_set(struct led_classdev_flash *fled_cdev,
bool state)
{
@@ -382,11 +354,9 @@ static int ktd2692_probe(struct platform_device *pdev)

led_cdev->max_brightness = led_cfg.max_brightness;
led_cdev->brightness_set = ktd2692_led_brightness_set;
- led_cdev->brightness_set_sync = ktd2692_led_brightness_set_sync;
led_cdev->flags |= LED_CORE_SUSPENDRESUME | LED_DEV_CAP_FLASH;

mutex_init(&led->lock);
- INIT_WORK(&led->work_brightness_set, ktd2692_brightness_set_work);

platform_set_drvdata(pdev, led);

@@ -408,7 +378,6 @@ static int ktd2692_remove(struct platform_device *pdev)
int ret;

led_classdev_flash_unregister(&led->fled_cdev);
- cancel_work_sync(&led->work_brightness_set);

if (led->regulator) {
ret = regulator_disable(led->regulator);
diff --git a/drivers/leds/leds-max77693.c b/drivers/leds/leds-max77693.c
index b8b0eec..797ab5b 100644
--- a/drivers/leds/leds-max77693.c
+++ b/drivers/leds/leds-max77693.c
@@ -19,7 +19,6 @@
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>
-#include <linux/workqueue.h>
#include <media/v4l2-flash-led-class.h>

#define MODE_OFF 0
@@ -61,8 +60,6 @@ struct max77693_sub_led {
int fled_id;
/* corresponding LED Flash class device */
struct led_classdev_flash fled_cdev;
- /* assures led-triggers compatibility */
- struct work_struct work_brightness_set;
/* V4L2 Flash device */
struct v4l2_flash *v4l2_flash;

@@ -462,10 +459,14 @@ static int max77693_setup(struct max77693_led_device *led,
return max77693_set_mode_reg(led, MODE_OFF);
}

-static int __max77693_led_brightness_set(struct max77693_led_device *led,
- int fled_id, enum led_brightness value)
+/* LED subsystem callbacks */
+static void max77693_led_brightness_set(struct led_classdev *led_cdev,
+ enum led_brightness value)
{
- int ret;
+ struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
+ struct max77693_sub_led *sub_led = flcdev_to_sub_led(fled_cdev);
+ struct max77693_led_device *led = sub_led_to_led(sub_led);
+ int fled_id = sub_led->fled_id, ret;

mutex_lock(&led->lock);

@@ -493,43 +494,6 @@ static int __max77693_led_brightness_set(struct max77693_led_device *led,
ret);
unlock:
mutex_unlock(&led->lock);
- return ret;
-}
-
-static void max77693_led_brightness_set_work(
- struct work_struct *work)
-{
- struct max77693_sub_led *sub_led =
- container_of(work, struct max77693_sub_led,
- work_brightness_set);
- struct max77693_led_device *led = sub_led_to_led(sub_led);
-
- __max77693_led_brightness_set(led, sub_led->fled_id,
- sub_led->torch_brightness);
-}
-
-/* LED subsystem callbacks */
-
-static int max77693_led_brightness_set_sync(
- struct led_classdev *led_cdev,
- enum led_brightness value)
-{
- struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
- struct max77693_sub_led *sub_led = flcdev_to_sub_led(fled_cdev);
- struct max77693_led_device *led = sub_led_to_led(sub_led);
-
- return __max77693_led_brightness_set(led, sub_led->fled_id, value);
-}
-
-static void max77693_led_brightness_set(
- struct led_classdev *led_cdev,
- enum led_brightness value)
-{
- struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
- struct max77693_sub_led *sub_led = flcdev_to_sub_led(fled_cdev);
-
- sub_led->torch_brightness = value;
- schedule_work(&sub_led->work_brightness_set);
}

static int max77693_led_flash_brightness_set(
@@ -931,15 +895,12 @@ static void max77693_init_fled_cdev(struct max77693_sub_led *sub_led,
led_cdev->name = led_cfg->label[fled_id];

led_cdev->brightness_set = max77693_led_brightness_set;
- led_cdev->brightness_set_sync = max77693_led_brightness_set_sync;
led_cdev->max_brightness = (led->iout_joint ?
led_cfg->iout_torch_max[FLED1] +
led_cfg->iout_torch_max[FLED2] :
led_cfg->iout_torch_max[fled_id]) /
TORCH_IOUT_STEP;
led_cdev->flags |= LED_DEV_CAP_FLASH;
- INIT_WORK(&sub_led->work_brightness_set,
- max77693_led_brightness_set_work);

max77693_init_flash_settings(sub_led, led_cfg);

@@ -1061,13 +1022,11 @@ static int max77693_led_remove(struct platform_device *pdev)
if (led->iout_joint || max77693_fled_used(led, FLED1)) {
v4l2_flash_release(sub_leds[FLED1].v4l2_flash);
led_classdev_flash_unregister(&sub_leds[FLED1].fled_cdev);
- cancel_work_sync(&sub_leds[FLED1].work_brightness_set);
}

if (!led->iout_joint && max77693_fled_used(led, FLED2)) {
v4l2_flash_release(sub_leds[FLED2].v4l2_flash);
led_classdev_flash_unregister(&sub_leds[FLED2].fled_cdev);
- cancel_work_sync(&sub_leds[FLED2].work_brightness_set);
}

mutex_destroy(&led->lock);
diff --git a/include/linux/leds.h b/include/linux/leds.h
index a982626..efe564b 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -45,22 +45,14 @@ struct led_classdev {
#define LED_BLINK_ONESHOT_STOP (1 << 18)
#define LED_BLINK_INVERT (1 << 19)
#define LED_SYSFS_DISABLE (1 << 20)
-#define SET_BRIGHTNESS_ASYNC (1 << 21)
-#define SET_BRIGHTNESS_SYNC (1 << 22)
-#define LED_DEV_CAP_FLASH (1 << 23)
-#define LED_BLINK_DISABLE (1 << 24)
-#define LED_BRIGHTNESS_FAST (1 << 25)
+#define LED_DEV_CAP_FLASH (1 << 21)
+#define LED_BLINK_DISABLE (1 << 22)
+#define LED_BRIGHTNESS_FAST (1 << 23)

/* Set LED brightness level */
/* Must not sleep, use a workqueue if needed */
void (*brightness_set)(struct led_classdev *led_cdev,
enum led_brightness brightness);
- /*
- * Set LED brightness level immediately - it can block the caller for
- * the time required for accessing a LED device register.
- */
- int (*brightness_set_sync)(struct led_classdev *led_cdev,
- enum led_brightness brightness);
/* Get LED brightness level */
enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);

@@ -159,7 +151,7 @@ extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
*
* Set an LED's brightness, and, if necessary, cancel the
* software blink timer that implements blinking when the
- * hardware doesn't.
+ * hardware doesn't. This function is guaranteed not to sleep.
*/
extern void led_set_brightness(struct led_classdev *led_cdev,
enum led_brightness brightness);
@@ -173,23 +165,15 @@ extern void led_set_brightness(struct led_classdev *led_cdev,
* the caller for the time required for accessing device register,
* and it can sleep.
*/
-static inline int led_set_brightness_sync(struct led_classdev *led_cdev,
+static inline void led_set_brightness_sync(struct led_classdev *led_cdev,
enum led_brightness value)
{
- int ret = 0;
-
led_cdev->brightness = min(value, led_cdev->max_brightness);

if (led_cdev->flags & LED_SUSPENDED)
- return 0;
-
- if (led_cdev->brightness_set_sync)
- ret = led_cdev->brightness_set_sync(led_cdev,
- led_cdev->brightness);
- else
- led_cdev->brightness_set(led_cdev, led_cdev->brightness);
+ return;

- return 0;
+ led_cdev->brightness_set(led_cdev, led_cdev->brightness);
}

/**
--
1.7.9.5

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