From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jacek Anaszewski Subject: [PATCH/RFC v5 3/4] leds: add API for setting torch brightness Date: Wed, 20 Aug 2014 15:41:57 +0200 Message-ID: <1408542118-32723-4-git-send-email-j.anaszewski@samsung.com> References: <1408542118-32723-1-git-send-email-j.anaszewski@samsung.com> Return-path: In-reply-to: <1408542118-32723-1-git-send-email-j.anaszewski@samsung.com> Sender: linux-kernel-owner@vger.kernel.org To: linux-leds@vger.kernel.org, devicetree@vger.kernel.org, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Cc: kyungmin.park@samsung.com, b.zolnierkie@samsung.com, Jacek Anaszewski , Bryan Wu , Richard Purdie List-Id: linux-leds@vger.kernel.org This patch prepares ground for addition of LED Flash Class extension to the LED subsystem. Since turning the torch on must have guaranteed immediate effect the brightness_set op can't be used for it. Drivers must schedule a work queue task in this op to be compatible with led-triggers, which call brightess_set from timer irqs. In order to address this limitation a torch_brightness_set op and led_set_torch_brightness API is introduced. Setting brightness sysfs attribute will result in calling brightness_set op for LED Class devices and torch_brightness_set op for LED Flash Class devices, whereas triggers will still call brightness op in both cases. Signed-off-by: Jacek Anaszewski Acked-by: Kyungmin Park Cc: Bryan Wu Cc: Richard Purdie --- drivers/leds/led-class.c | 9 +++++++-- drivers/leds/led-core.c | 14 ++++++++++++++ include/linux/leds.h | 21 +++++++++++++++++++++ 3 files changed, 42 insertions(+), 2 deletions(-) diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c index 0bc0ba9..f640da9 100644 --- a/drivers/leds/led-class.c +++ b/drivers/leds/led-class.c @@ -56,9 +56,14 @@ static ssize_t brightness_store(struct device *dev, if (state == LED_OFF) led_trigger_remove(led_cdev); - __led_set_brightness(led_cdev, state); - ret = size; + if (led_cdev->flags & LED_DEV_CAP_TORCH) + ret = led_set_torch_brightness(led_cdev, state); + else + __led_set_brightness(led_cdev, state); + + if (!ret) + ret = size; unlock: #ifdef CONFIG_V4L2_FLASH_LED_CLASS mutex_unlock(&led_cdev->led_lock); diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c index 4649ea5..093265f 100644 --- a/drivers/leds/led-core.c +++ b/drivers/leds/led-core.c @@ -144,6 +144,20 @@ int led_update_brightness(struct led_classdev *led_cdev) } EXPORT_SYMBOL(led_update_brightness); +int led_set_torch_brightness(struct led_classdev *led_cdev, + enum led_brightness brightness) +{ + int ret = 0; + + led_cdev->brightness = min(brightness, led_cdev->max_brightness); + + if (!(led_cdev->flags & LED_SUSPENDED)) + ret = led_cdev->torch_brightness_set(led_cdev, + led_cdev->brightness); + return ret; +} +EXPORT_SYMBOL_GPL(led_set_torch_brightness); + /* Caller must ensure led_cdev->led_lock held */ void led_sysfs_lock(struct led_classdev *led_cdev) { diff --git a/include/linux/leds.h b/include/linux/leds.h index ef343f1..df0715c 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -43,11 +43,21 @@ struct led_classdev { #define LED_BLINK_ONESHOT_STOP (1 << 18) #define LED_BLINK_INVERT (1 << 19) #define LED_SYSFS_LOCK (1 << 20) +#define LED_DEV_CAP_TORCH (1 << 21) /* 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 immediately - it is required for flash led + * devices as they require setting torch brightness to have immediate + * effect. brightness_set op cannot be used for this purpose because + * the led drivers schedule a work queue task in it to allow for + * being called from led-triggers, i.e. from the timer irq context. + */ + int (*torch_brightness_set)(struct led_classdev *led_cdev, + enum led_brightness brightness); /* Get LED brightness level */ enum led_brightness (*brightness_get)(struct led_classdev *led_cdev); @@ -156,6 +166,17 @@ extern void led_set_brightness(struct led_classdev *led_cdev, extern int led_update_brightness(struct led_classdev *led_cdev); /** + * led_set_torch_brightness - set torch LED brightness + * @led_cdev: the LED to set + * @brightness: the brightness to set it to + * + * Returns: 0 on success or negative error value on failure + * + * Set a torch LED's brightness. + */ +extern int led_set_torch_brightness(struct led_classdev *led_cdev, + enum led_brightness brightness); +/** * led_sysfs_lock - lock LED sysfs interface * @led_cdev: the LED to set * -- 1.7.9.5