* [PATCH/RFC v5 2/4] leds: implement sysfs interface locking mechanism
2014-08-20 13:41 ` Jacek Anaszewski
(?)
(?)
@ 2014-08-20 13:41 ` Jacek Anaszewski
2014-09-12 1:11 ` Bryan Wu
-1 siblings, 1 reply; 11+ messages in thread
From: Jacek Anaszewski @ 2014-08-20 13:41 UTC (permalink / raw)
To: linux-leds, devicetree, linux-media, linux-kernel
Cc: kyungmin.park, b.zolnierkie, Jacek Anaszewski, Bryan Wu, Richard Purdie
Add a mechanism for locking LED subsystem sysfs interface.
This patch prepares ground for addition of LED Flash Class
extension, whose API will be integrated with V4L2 Flash API.
Such a fusion enforces introducing a locking scheme, which
will secure consistent access to the LED Flash Class device.
The mechanism being introduced allows for disabling LED
subsystem sysfs interface by calling led_sysfs_lock function
and enabling it by calling led_sysfs_unlock. The functions
alter the LED_SYSFS_LOCK flag state and must be called
under mutex lock. The state of the lock is checked with use
of led_sysfs_is_locked function. Such a design allows for
providing immediate feedback to the user space on whether
the LED Flash Class device is available or is under V4L2 Flash
sub-device control.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Bryan Wu <cooloney@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
---
drivers/leds/led-class.c | 23 ++++++++++++++++++++---
drivers/leds/led-core.c | 18 ++++++++++++++++++
drivers/leds/led-triggers.c | 15 ++++++++++++---
include/linux/leds.h | 32 ++++++++++++++++++++++++++++++++
4 files changed, 82 insertions(+), 6 deletions(-)
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 6f82a76..0bc0ba9 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -39,17 +39,31 @@ static ssize_t brightness_store(struct device *dev,
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
unsigned long state;
- ssize_t ret = -EINVAL;
+ ssize_t ret;
+
+#ifdef CONFIG_V4L2_FLASH_LED_CLASS
+ mutex_lock(&led_cdev->led_lock);
+
+ if (led_sysfs_is_locked(led_cdev)) {
+ ret = -EBUSY;
+ goto unlock;
+ }
+#endif
ret = kstrtoul(buf, 10, &state);
if (ret)
- return ret;
+ goto unlock;
if (state == LED_OFF)
led_trigger_remove(led_cdev);
__led_set_brightness(led_cdev, state);
- return size;
+ ret = size;
+unlock:
+#ifdef CONFIG_V4L2_FLASH_LED_CLASS
+ mutex_unlock(&led_cdev->led_lock);
+#endif
+ return ret;
}
static DEVICE_ATTR_RW(brightness);
@@ -215,6 +229,7 @@ int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
#ifdef CONFIG_LEDS_TRIGGERS
init_rwsem(&led_cdev->trigger_lock);
#endif
+ mutex_init(&led_cdev->led_lock);
/* add to the list of leds */
down_write(&leds_list_lock);
list_add_tail(&led_cdev->node, &leds_list);
@@ -266,6 +281,8 @@ void led_classdev_unregister(struct led_classdev *led_cdev)
down_write(&leds_list_lock);
list_del(&led_cdev->node);
up_write(&leds_list_lock);
+
+ mutex_destroy(&led_cdev->led_lock);
}
EXPORT_SYMBOL_GPL(led_classdev_unregister);
diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
index 466ce5a..4649ea5 100644
--- a/drivers/leds/led-core.c
+++ b/drivers/leds/led-core.c
@@ -143,3 +143,21 @@ int led_update_brightness(struct led_classdev *led_cdev)
return ret;
}
EXPORT_SYMBOL(led_update_brightness);
+
+/* Caller must ensure led_cdev->led_lock held */
+void led_sysfs_lock(struct led_classdev *led_cdev)
+{
+ lockdep_assert_held(&led_cdev->led_lock);
+
+ led_cdev->flags |= LED_SYSFS_LOCK;
+}
+EXPORT_SYMBOL_GPL(led_sysfs_lock);
+
+/* Caller must ensure led_cdev->led_lock held */
+void led_sysfs_unlock(struct led_classdev *led_cdev)
+{
+ lockdep_assert_held(&led_cdev->led_lock);
+
+ led_cdev->flags &= ~LED_SYSFS_LOCK;
+}
+EXPORT_SYMBOL_GPL(led_sysfs_unlock);
diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
index c3734f1..d391a5d 100644
--- a/drivers/leds/led-triggers.c
+++ b/drivers/leds/led-triggers.c
@@ -37,6 +37,11 @@ ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
char trigger_name[TRIG_NAME_MAX];
struct led_trigger *trig;
size_t len;
+ int ret = count;
+
+#ifdef CONFIG_V4L2_FLASH_LED_CLASS
+ mutex_lock(&led_cdev->led_lock);
+#endif
trigger_name[sizeof(trigger_name) - 1] = '\0';
strncpy(trigger_name, buf, sizeof(trigger_name) - 1);
@@ -47,7 +52,7 @@ ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
if (!strcmp(trigger_name, "none")) {
led_trigger_remove(led_cdev);
- return count;
+ goto exit_unlock;
}
down_read(&triggers_list_lock);
@@ -58,12 +63,16 @@ ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
up_write(&led_cdev->trigger_lock);
up_read(&triggers_list_lock);
- return count;
+ goto exit_unlock;
}
}
up_read(&triggers_list_lock);
- return -EINVAL;
+exit_unlock:
+#ifdef CONFIG_V4L2_FLASH_LED_CLASS
+ mutex_unlock(&led_cdev->led_lock);
+#endif
+ return ret;
}
EXPORT_SYMBOL_GPL(led_trigger_store);
diff --git a/include/linux/leds.h b/include/linux/leds.h
index cc85b16..ef343f1 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -13,6 +13,7 @@
#define __LINUX_LEDS_H_INCLUDED
#include <linux/list.h>
+#include <linux/mutex.h>
#include <linux/rwsem.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
@@ -41,6 +42,7 @@ struct led_classdev {
#define LED_BLINK_ONESHOT (1 << 17)
#define LED_BLINK_ONESHOT_STOP (1 << 18)
#define LED_BLINK_INVERT (1 << 19)
+#define LED_SYSFS_LOCK (1 << 20)
/* Set LED brightness level */
/* Must not sleep, use a workqueue if needed */
@@ -84,6 +86,9 @@ struct led_classdev {
/* true if activated - deactivate routine uses it to do cleanup */
bool activated;
#endif
+
+ /* Ensures consistent access to the LED Flash Class device */
+ struct mutex led_lock;
};
extern int led_classdev_register(struct device *parent,
@@ -150,6 +155,33 @@ extern void led_set_brightness(struct led_classdev *led_cdev,
*/
extern int led_update_brightness(struct led_classdev *led_cdev);
+/**
+ * led_sysfs_lock - lock LED sysfs interface
+ * @led_cdev: the LED to set
+ *
+ * Lock the LED's sysfs interface
+ */
+extern void led_sysfs_lock(struct led_classdev *led_cdev);
+
+/**
+ * led_sysfs_unlock - unlock LED sysfs interface
+ * @led_cdev: the LED to set
+ *
+ * Unlock the LED's sysfs interface
+ */
+extern void led_sysfs_unlock(struct led_classdev *led_cdev);
+
+/**
+ * led_sysfs_is_locked
+ * @led_cdev: the LED to query
+ *
+ * Returns: true if the sysfs interface of the led is locked
+ */
+static inline bool led_sysfs_is_locked(struct led_classdev *led_cdev)
+{
+ return led_cdev->flags & LED_SYSFS_LOCK;
+}
+
/*
* LED Triggers
*/
--
1.7.9.5
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH/RFC v5 4/4] leds: Add LED Flash Class wrapper to LED subsystem
2014-08-20 13:41 ` Jacek Anaszewski
` (3 preceding siblings ...)
(?)
@ 2014-08-20 13:41 ` Jacek Anaszewski
-1 siblings, 0 replies; 11+ messages in thread
From: Jacek Anaszewski @ 2014-08-20 13:41 UTC (permalink / raw)
To: linux-leds, devicetree, linux-media, linux-kernel
Cc: kyungmin.park, b.zolnierkie, Jacek Anaszewski, Bryan Wu, Richard Purdie
Some LED devices support two operation modes - torch and flash.
This patch provides support for flash LED devices in the LED subsystem
by introducing new sysfs attributes and kernel internal interface.
The attributes being introduced are: flash_brightness, flash_strobe,
flash_timeout, max_flash_timeout, max_flash_brightness, flash_fault,
external_strobe, indicator_brightness, max_indicator_brightness.
All the flash related features are placed in a separate module.
The modifications aim to be compatible with V4L2 framework requirements
related to the flash devices management. The design assumes that V4L2
sub-device can take of the LED class device control and communicate
with it through the kernel internal interface. When V4L2 Flash sub-device
file is opened, the LED class device sysfs interface is made
unavailable.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Bryan Wu <cooloney@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
---
drivers/leds/Kconfig | 11 +
drivers/leds/Makefile | 1 +
drivers/leds/led-class-flash.c | 645 +++++++++++++++++++++++++++++++++++++++
drivers/leds/led-class.c | 4 +
drivers/leds/led-triggers.c | 5 +
include/linux/led-class-flash.h | 273 +++++++++++++++++
include/linux/leds.h | 3 +
7 files changed, 942 insertions(+)
create mode 100644 drivers/leds/led-class-flash.c
create mode 100644 include/linux/led-class-flash.h
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index f6e32ba..a22c211 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -19,6 +19,17 @@ config LEDS_CLASS
This option enables the led sysfs class in /sys/class/leds. You'll
need this to do anything useful with LEDs. If unsure, say N.
+config LEDS_CLASS_FLASH
+ tristate "LED Flash Class Support"
+ depends on LEDS_CLASS
+ depends on OF
+ help
+ This option enables the flash led sysfs class in /sys/class/leds.
+ It wrapps LED Class and adds flash LEDs specific sysfs attributes
+ and kernel internal API to it. You'll need this to provide support
+ for the flash related features of a LED device. It can be built
+ as a module.
+
comment "LED drivers"
config LEDS_88PM860X
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index d8cc5f2..9238b8a 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -2,6 +2,7 @@
# LED Core
obj-$(CONFIG_NEW_LEDS) += led-core.o
obj-$(CONFIG_LEDS_CLASS) += led-class.o
+obj-$(CONFIG_LEDS_CLASS_FLASH) += led-class-flash.o
obj-$(CONFIG_LEDS_TRIGGERS) += led-triggers.o
# LED Platform Drivers
diff --git a/drivers/leds/led-class-flash.c b/drivers/leds/led-class-flash.c
new file mode 100644
index 0000000..4132769
--- /dev/null
+++ b/drivers/leds/led-class-flash.c
@@ -0,0 +1,645 @@
+/*
+ * LED Flash Class interface
+ *
+ * Copyright (C) 2014 Samsung Electronics Co., Ltd.
+ * Author: Jacek Anaszewski <j.anaszewski@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/leds.h>
+#include <linux/led-class-flash.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include "leds.h"
+
+#define has_flash_op(flash, op) \
+ (flash && flash->ops->op)
+
+#define call_flash_op(flash, op, args...) \
+ ((has_flash_op(flash, op)) ? \
+ (flash->ops->op(flash, args)) : \
+ -EINVAL)
+
+static ssize_t flash_brightness_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t size)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct led_classdev_flash *flash = lcdev_to_flash(led_cdev);
+ unsigned long state;
+ ssize_t ret;
+
+ mutex_lock(&led_cdev->led_lock);
+
+ if (led_sysfs_is_locked(led_cdev)) {
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ ret = kstrtoul(buf, 10, &state);
+ if (ret)
+ goto unlock;
+
+ ret = led_set_flash_brightness(flash, state);
+ if (ret < 0)
+ goto unlock;
+
+ ret = size;
+unlock:
+ mutex_unlock(&led_cdev->led_lock);
+ return ret;
+}
+
+static ssize_t flash_brightness_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct led_classdev_flash *flash = lcdev_to_flash(led_cdev);
+
+ /* no lock needed for this */
+ led_update_flash_brightness(flash);
+
+ return sprintf(buf, "%u\n", flash->brightness.val);
+}
+static DEVICE_ATTR_RW(flash_brightness);
+
+static ssize_t max_flash_brightness_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct led_classdev_flash *flash = lcdev_to_flash(led_cdev);
+
+ return sprintf(buf, "%u\n", flash->brightness.max);
+}
+static DEVICE_ATTR_RO(max_flash_brightness);
+
+static ssize_t indicator_brightness_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t size)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct led_classdev_flash *flash = lcdev_to_flash(led_cdev);
+ unsigned long state;
+ ssize_t ret;
+
+ mutex_lock(&led_cdev->led_lock);
+
+ if (led_sysfs_is_locked(led_cdev)) {
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ ret = kstrtoul(buf, 10, &state);
+ if (ret)
+ goto unlock;
+
+ ret = led_set_indicator_brightness(flash, state);
+ if (ret < 0)
+ goto unlock;
+
+ ret = size;
+unlock:
+ mutex_unlock(&led_cdev->led_lock);
+ return ret;
+}
+
+static ssize_t indicator_brightness_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct led_classdev_flash *flash = lcdev_to_flash(led_cdev);
+
+ /* no lock needed for this */
+ led_update_indicator_brightness(flash);
+
+ return sprintf(buf, "%u\n", flash->indicator_brightness->val);
+}
+static DEVICE_ATTR_RW(indicator_brightness);
+
+static ssize_t max_indicator_brightness_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct led_classdev_flash *flash = lcdev_to_flash(led_cdev);
+
+ return sprintf(buf, "%u\n", flash->indicator_brightness->max);
+}
+static DEVICE_ATTR_RO(max_indicator_brightness);
+
+static ssize_t flash_strobe_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t size)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct led_classdev_flash *flash = lcdev_to_flash(led_cdev);
+ unsigned long state;
+ ssize_t ret = -EINVAL;
+
+ mutex_lock(&led_cdev->led_lock);
+
+ if (led_sysfs_is_locked(led_cdev)) {
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ ret = kstrtoul(buf, 10, &state);
+ if (ret)
+ goto unlock;
+
+ if (state < 0 || state > 1) {
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ ret = led_set_flash_strobe(flash, state);
+ if (ret < 0)
+ goto unlock;
+ ret = size;
+unlock:
+ mutex_unlock(&led_cdev->led_lock);
+ return ret;
+}
+
+static ssize_t flash_strobe_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct led_classdev_flash *flash = lcdev_to_flash(led_cdev);
+ bool state;
+ int ret;
+
+ /* no lock needed for this */
+ ret = led_get_flash_strobe(flash, &state);
+ if (ret < 0)
+ return ret;
+
+ return sprintf(buf, "%u\n", state);
+}
+static DEVICE_ATTR_RW(flash_strobe);
+
+static ssize_t flash_timeout_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t size)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct led_classdev_flash *flash = lcdev_to_flash(led_cdev);
+ unsigned long flash_timeout;
+ ssize_t ret;
+
+ mutex_lock(&led_cdev->led_lock);
+
+ if (led_sysfs_is_locked(led_cdev)) {
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ ret = kstrtoul(buf, 10, &flash_timeout);
+ if (ret)
+ goto unlock;
+
+ ret = led_set_flash_timeout(flash, flash_timeout);
+ if (ret < 0)
+ goto unlock;
+
+ ret = size;
+unlock:
+ mutex_unlock(&led_cdev->led_lock);
+ return ret;
+}
+
+static ssize_t flash_timeout_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct led_classdev_flash *flash = lcdev_to_flash(led_cdev);
+
+ return sprintf(buf, "%u\n", flash->timeout.val);
+}
+static DEVICE_ATTR_RW(flash_timeout);
+
+static ssize_t max_flash_timeout_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct led_classdev_flash *flash = lcdev_to_flash(led_cdev);
+
+ return sprintf(buf, "%u\n", flash->timeout.max);
+}
+static DEVICE_ATTR_RO(max_flash_timeout);
+
+static ssize_t flash_fault_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct led_classdev_flash *flash = lcdev_to_flash(led_cdev);
+ u32 fault;
+ int ret;
+
+ ret = led_get_flash_fault(flash, &fault);
+ if (ret < 0)
+ return -EINVAL;
+
+ return sprintf(buf, "0x%8.8x\n", fault);
+}
+static DEVICE_ATTR_RO(flash_fault);
+
+static ssize_t external_strobe_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t size)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct led_classdev_flash *flash = lcdev_to_flash(led_cdev);
+ unsigned long external_strobe;
+ ssize_t ret;
+
+ mutex_lock(&led_cdev->led_lock);
+
+ if (led_sysfs_is_locked(led_cdev)) {
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ ret = kstrtoul(buf, 10, &external_strobe);
+ if (ret)
+ goto unlock;
+
+ if (external_strobe > 1) {
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ ret = led_set_external_strobe(flash, external_strobe);
+ if (ret < 0)
+ goto unlock;
+ ret = size;
+unlock:
+ mutex_unlock(&led_cdev->led_lock);
+ return ret;
+}
+
+static ssize_t external_strobe_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct led_classdev_flash *flash = lcdev_to_flash(led_cdev);
+
+ return sprintf(buf, "%u\n", flash->external_strobe);
+}
+static DEVICE_ATTR_RW(external_strobe);
+
+static struct attribute *led_flash_strobe_attrs[] = {
+ &dev_attr_flash_strobe.attr,
+ NULL,
+};
+
+static struct attribute *led_flash_indicator_attrs[] = {
+ &dev_attr_indicator_brightness.attr,
+ &dev_attr_max_indicator_brightness.attr,
+ NULL,
+};
+
+static struct attribute *led_flash_timeout_attrs[] = {
+ &dev_attr_flash_timeout.attr,
+ &dev_attr_max_flash_timeout.attr,
+ NULL,
+};
+
+static struct attribute *led_flash_brightness_attrs[] = {
+ &dev_attr_flash_brightness.attr,
+ &dev_attr_max_flash_brightness.attr,
+ NULL,
+};
+
+static struct attribute *led_flash_external_strobe_attrs[] = {
+ &dev_attr_external_strobe.attr,
+ NULL,
+};
+
+static struct attribute *led_flash_fault_attrs[] = {
+ &dev_attr_flash_fault.attr,
+ NULL,
+};
+
+static struct attribute_group led_flash_strobe_group = {
+ .attrs = led_flash_strobe_attrs,
+};
+
+static struct attribute_group led_flash_brightness_group = {
+ .attrs = led_flash_brightness_attrs,
+};
+
+static struct attribute_group led_flash_timeout_group = {
+ .attrs = led_flash_timeout_attrs,
+};
+
+static struct attribute_group led_flash_indicator_group = {
+ .attrs = led_flash_indicator_attrs,
+};
+
+static struct attribute_group led_flash_fault_group = {
+ .attrs = led_flash_fault_attrs,
+};
+
+static struct attribute_group led_flash_external_strobe_group = {
+ .attrs = led_flash_external_strobe_attrs,
+};
+
+static void led_flash_resume(struct led_classdev *led_cdev)
+{
+ struct led_classdev_flash *flash = lcdev_to_flash(led_cdev);
+
+ call_flash_op(flash, flash_brightness_set, flash->brightness.val);
+ call_flash_op(flash, timeout_set, flash->timeout.val);
+ call_flash_op(flash, indicator_brightness_set,
+ flash->indicator_brightness->val);
+}
+
+static void led_flash_remove_sysfs_groups(struct led_classdev_flash *flash)
+{
+ struct led_classdev *led_cdev = &flash->led_cdev;
+ int i;
+
+ for (i = 0; i < LED_FLASH_MAX_SYSFS_GROUPS; ++i)
+ if (flash->sysfs_groups[i])
+ sysfs_remove_group(&led_cdev->dev->kobj,
+ flash->sysfs_groups[i]);
+}
+
+static int led_flash_create_sysfs_groups(struct led_classdev_flash *flash)
+{
+ struct led_classdev *led_cdev = &flash->led_cdev;
+ const struct led_flash_ops *ops = flash->ops;
+ int ret, num_sysfs_groups = 0;
+
+ memset(flash->sysfs_groups, 0, sizeof(*flash->sysfs_groups) *
+ LED_FLASH_MAX_SYSFS_GROUPS);
+
+ ret = sysfs_create_group(&led_cdev->dev->kobj, &led_flash_strobe_group);
+ if (ret < 0)
+ goto err_create_group;
+ flash->sysfs_groups[num_sysfs_groups++] = &led_flash_strobe_group;
+
+ if (flash->indicator_brightness) {
+ ret = sysfs_create_group(&led_cdev->dev->kobj,
+ &led_flash_indicator_group);
+ if (ret < 0)
+ goto err_create_group;
+ flash->sysfs_groups[num_sysfs_groups++] =
+ &led_flash_indicator_group;
+ }
+
+ if (ops->flash_brightness_set) {
+ ret = sysfs_create_group(&led_cdev->dev->kobj,
+ &led_flash_brightness_group);
+ if (ret < 0)
+ goto err_create_group;
+ flash->sysfs_groups[num_sysfs_groups++] =
+ &led_flash_brightness_group;
+ }
+
+ if (ops->timeout_set) {
+ ret = sysfs_create_group(&led_cdev->dev->kobj,
+ &led_flash_timeout_group);
+ if (ret < 0)
+ goto err_create_group;
+ flash->sysfs_groups[num_sysfs_groups++] =
+ &led_flash_timeout_group;
+ }
+
+ if (ops->fault_get) {
+ ret = sysfs_create_group(&led_cdev->dev->kobj,
+ &led_flash_fault_group);
+ if (ret < 0)
+ goto err_create_group;
+ flash->sysfs_groups[num_sysfs_groups++] =
+ &led_flash_fault_group;
+ }
+
+ if (flash->has_external_strobe) {
+ ret = sysfs_create_group(&led_cdev->dev->kobj,
+ &led_flash_external_strobe_group);
+ if (ret < 0)
+ goto err_create_group;
+ flash->sysfs_groups[num_sysfs_groups++] =
+ &led_flash_external_strobe_group;
+ }
+
+ return 0;
+
+err_create_group:
+ led_flash_remove_sysfs_groups(flash);
+ return ret;
+}
+
+int led_classdev_flash_register(struct device *parent,
+ struct led_classdev_flash *flash,
+ struct device_node *node)
+{
+ struct led_classdev *led_cdev;
+ const struct led_flash_ops *ops;
+ int ret = -EINVAL;
+
+ if (!flash)
+ return -EINVAL;
+
+ led_cdev = &flash->led_cdev;
+
+ /* Torch capability is default for every LED Flash Class device */
+ led_cdev->flags |= LED_DEV_CAP_TORCH;
+
+ if (led_cdev->flags & LED_DEV_CAP_FLASH) {
+ if (!led_cdev->torch_brightness_set)
+ return -EINVAL;
+
+ ops = flash->ops;
+ if (!ops || !ops->strobe_set)
+ return -EINVAL;
+
+ if ((led_cdev->flags & LED_DEV_CAP_INDICATOR) &&
+ (!flash->indicator_brightness ||
+ !ops->indicator_brightness_set))
+ return -EINVAL;
+
+ led_cdev->flash_resume = led_flash_resume;
+ }
+
+ /* Register led class device */
+ ret = led_classdev_register(parent, led_cdev);
+ if (ret < 0)
+ return -EINVAL;
+
+ /* Create flash led specific sysfs attributes */
+ ret = led_flash_create_sysfs_groups(flash);
+ if (ret < 0)
+ goto err_create_sysfs_groups;
+
+ return 0;
+
+err_create_sysfs_groups:
+ led_classdev_unregister(led_cdev);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(led_classdev_flash_register);
+
+void led_classdev_flash_unregister(struct led_classdev_flash *flash)
+{
+ if (!flash)
+ return;
+
+ led_flash_remove_sysfs_groups(flash);
+ led_classdev_unregister(&flash->led_cdev);
+}
+EXPORT_SYMBOL_GPL(led_classdev_flash_unregister);
+
+int led_set_flash_strobe(struct led_classdev_flash *flash, bool state)
+{
+ if (flash->external_strobe)
+ return -EBUSY;
+
+ return call_flash_op(flash, strobe_set, state);
+}
+EXPORT_SYMBOL_GPL(led_set_flash_strobe);
+
+int led_get_flash_strobe(struct led_classdev_flash *flash, bool *state)
+{
+ return call_flash_op(flash, strobe_get, state);
+}
+EXPORT_SYMBOL_GPL(led_get_flash_strobe);
+
+void led_clamp_align(struct led_flash_setting *s)
+{
+ u32 v, offset;
+
+ v = s->val + s->step / 2;
+ v = clamp(v, s->min, s->max);
+ offset = v - s->min;
+ offset = s->step * (offset / s->step);
+ s->val = s->min + offset;
+}
+
+int led_set_flash_timeout(struct led_classdev_flash *flash, u32 timeout)
+{
+ struct led_classdev *led_cdev = &flash->led_cdev;
+ struct led_flash_setting *s = &flash->timeout;
+ int ret = 0;
+
+ s->val = timeout;
+ led_clamp_align(s);
+
+ if (!(led_cdev->flags & LED_SUSPENDED))
+ ret = call_flash_op(flash, timeout_set, s->val);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(led_set_flash_timeout);
+
+int led_get_flash_fault(struct led_classdev_flash *flash, u32 *fault)
+{
+ return call_flash_op(flash, fault_get, fault);
+}
+EXPORT_SYMBOL_GPL(led_get_flash_fault);
+
+int led_set_external_strobe(struct led_classdev_flash *flash, bool enable)
+{
+ int ret;
+
+ if (flash->has_external_strobe) {
+ /*
+ * Some flash led devices need altering their register
+ * settings to start listen to the external strobe signal.
+ */
+ if (has_flash_op(flash, external_strobe_set)) {
+ ret = call_flash_op(flash, external_strobe_set, enable);
+ if (ret < 0)
+ return ret;
+ }
+
+ flash->external_strobe = enable;
+ } else if (enable) {
+ return -EINVAL;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(led_set_external_strobe);
+
+int led_set_flash_brightness(struct led_classdev_flash *flash,
+ u32 brightness)
+{
+ struct led_classdev *led_cdev = &flash->led_cdev;
+ struct led_flash_setting *s = &flash->brightness;
+ int ret = 0;
+
+ s->val = brightness;
+ led_clamp_align(s);
+
+ if (!(led_cdev->flags & LED_SUSPENDED))
+ ret = call_flash_op(flash, flash_brightness_set, s->val);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(led_set_flash_brightness);
+
+int led_update_flash_brightness(struct led_classdev_flash *flash)
+{
+ struct led_flash_setting *s = &flash->brightness;
+ u32 brightness;
+ int ret = 0;
+
+ if (has_flash_op(flash, flash_brightness_get)) {
+ ret = call_flash_op(flash, flash_brightness_get,
+ &brightness);
+ if (ret < 0)
+ return ret;
+ s->val = brightness;
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(led_update_flash_brightness);
+
+int led_set_indicator_brightness(struct led_classdev_flash *flash,
+ u32 brightness)
+{
+ struct led_classdev *led_cdev = &flash->led_cdev;
+ struct led_flash_setting *s = flash->indicator_brightness;
+ int ret = 0;
+
+ if (!s)
+ return -EINVAL;
+
+ s->val = brightness;
+ led_clamp_align(s);
+
+ if (!(led_cdev->flags & LED_SUSPENDED))
+ ret = call_flash_op(flash, indicator_brightness_set, s->val);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(led_set_indicator_brightness);
+
+int led_update_indicator_brightness(struct led_classdev_flash *flash)
+{
+ struct led_flash_setting *s = flash->indicator_brightness;
+ u32 brightness;
+ int ret = 0;
+
+ if (!s)
+ return -EINVAL;
+
+ if (has_flash_op(flash, indicator_brightness_get)) {
+ ret = call_flash_op(flash, indicator_brightness_get,
+ &brightness);
+ if (ret < 0)
+ return ret;
+ s->val = brightness;
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(led_update_indicator_brightness);
+
+MODULE_AUTHOR("Jacek Anaszewski <j.anaszewski@samsung.com>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("LED Flash Class Interface");
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index f640da9..86a03a0 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -189,6 +189,10 @@ EXPORT_SYMBOL_GPL(led_classdev_suspend);
void led_classdev_resume(struct led_classdev *led_cdev)
{
led_cdev->brightness_set(led_cdev, led_cdev->brightness);
+
+ if (led_cdev->flash_resume)
+ led_cdev->flash_resume(led_cdev);
+
led_cdev->flags &= ~LED_SUSPENDED;
}
EXPORT_SYMBOL_GPL(led_classdev_resume);
diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
index d391a5d..d80a8f3 100644
--- a/drivers/leds/led-triggers.c
+++ b/drivers/leds/led-triggers.c
@@ -43,6 +43,11 @@ ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
mutex_lock(&led_cdev->led_lock);
#endif
+ if (led_sysfs_is_locked(led_cdev)) {
+ ret = -EBUSY;
+ goto exit_unlock;
+ }
+
trigger_name[sizeof(trigger_name) - 1] = '\0';
strncpy(trigger_name, buf, sizeof(trigger_name) - 1);
len = strlen(trigger_name);
diff --git a/include/linux/led-class-flash.h b/include/linux/led-class-flash.h
new file mode 100644
index 0000000..a882263
--- /dev/null
+++ b/include/linux/led-class-flash.h
@@ -0,0 +1,273 @@
+/*
+ * LED Flash Class interface
+ *
+ * Copyright (C) 2014 Samsung Electronics Co., Ltd.
+ * Author: Jacek Anaszewski <j.anaszewski@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+#ifndef __LINUX_FLASH_LEDS_H_INCLUDED
+#define __LINUX_FLASH_LEDS_H_INCLUDED
+
+#include <linux/leds.h>
+
+struct led_classdev_flash;
+struct device_node;
+
+/*
+ * Supported led fault bits - must be kept in synch
+ * with V4L2_FLASH_FAULT bits.
+ */
+#define LED_FAULT_OVER_VOLTAGE V4L2_FLASH_FAULT_OVER_VOLTAGE
+#define LED_FAULT_TIMEOUT V4L2_FLASH_FAULT_TIMEOUT
+#define LED_FAULT_OVER_TEMPERATURE V4L2_FLASH_FAULT_OVER_TEMPERATURE
+#define LED_FAULT_SHORT_CIRCUIT V4L2_FLASH_FAULT_SHORT_CIRCUIT
+#define LED_FAULT_OVER_CURRENT V4L2_FLASH_FAULT_OVER_CURRENT
+#define LED_FAULT_INDICATOR V4L2_FLASH_FAULT_INDICATOR
+#define LED_FAULT_UNDER_VOLTAGE V4L2_FLASH_FAULT_UNDER_VOLTAGE
+#define LED_FAULT_INPUT_VOLTAGE V4L2_FLASH_FAULT_INPUT_VOLTAGE
+#define LED_FAULT_LED_OVER_TEMPERATURE V4L2_FLASH_OVER_TEMPERATURE
+
+#define LED_FLASH_MAX_SYSFS_GROUPS 6
+
+struct led_flash_ops {
+ /* set flash brightness */
+ int (*flash_brightness_set)(struct led_classdev_flash *flash,
+ u32 brightness);
+ /* get flash brightness */
+ int (*flash_brightness_get)(struct led_classdev_flash *flash,
+ u32 *brightness);
+ /* set flash indicator brightness */
+ int (*indicator_brightness_set)(struct led_classdev_flash *flash,
+ u32 brightness);
+ /* get flash indicator brightness */
+ int (*indicator_brightness_get)(struct led_classdev_flash *flash,
+ u32 *brightness);
+ /* set flash strobe state */
+ int (*strobe_set)(struct led_classdev_flash *flash, bool state);
+ /* get flash strobe state */
+ int (*strobe_get)(struct led_classdev_flash *flash, bool *state);
+ /* set flash timeout */
+ int (*timeout_set)(struct led_classdev_flash *flash, u32 timeout);
+ /* setup the device to strobe the flash upon a pin state assertion */
+ int (*external_strobe_set)(struct led_classdev_flash *flash,
+ bool enable);
+ /* get the flash LED fault */
+ int (*fault_get)(struct led_classdev_flash *flash, u32 *fault);
+};
+
+/*
+ * Current value of a flash setting along
+ * with its constraints.
+ */
+struct led_flash_setting {
+ /* maximum allowed value */
+ u32 min;
+ /* maximum allowed value */
+ u32 max;
+ /* step value */
+ u32 step;
+ /* current value */
+ u32 val;
+};
+
+/*
+ * Aggregated flash settings - designed for ease
+ * of passing initialization data to the clients
+ * wrapping a LED Flash class device.
+ */
+struct led_flash_config {
+ struct led_flash_setting torch_brightness;
+ struct led_flash_setting flash_brightness;
+ struct led_flash_setting indicator_brightness;
+ struct led_flash_setting flash_timeout;
+ u32 flash_faults;
+};
+
+struct led_classdev_flash {
+ /* led-flash-manager uses it to link flashes */
+ struct list_head list;
+ /* led class device */
+ struct led_classdev led_cdev;
+ /* flash led specific ops */
+ const struct led_flash_ops *ops;
+
+ /* flash sysfs groups */
+ struct attribute_group *sysfs_groups[LED_FLASH_MAX_SYSFS_GROUPS];
+
+ /* flash brightness value in microamperes along with its constraints */
+ struct led_flash_setting brightness;
+
+ /* timeout value in microseconds along with its constraints */
+ struct led_flash_setting timeout;
+
+ /*
+ * Indicator brightness value in microamperes along with
+ * its constraints - this is an optional setting and must
+ * be allocated by the driver if the device supports privacy
+ * indicator led.
+ */
+ struct led_flash_setting *indicator_brightness;
+
+ /*
+ * determines if a device supports external
+ * flash strobe sources
+ */
+ bool has_external_strobe;
+
+ /* If true the flash led is strobed from external source */
+ bool external_strobe;
+
+ /* Flash manager data */
+ /* Strobe signals topology data */
+ struct list_head software_strobe_gates;
+ struct list_head strobe_providers;
+
+ /* identifier of the selected strobe signal provider */
+ int strobe_provider_id;
+
+ /* number of defined strobe providers */
+ int num_strobe_providers;
+};
+
+static inline struct led_classdev_flash *lcdev_to_flash(
+ struct led_classdev *lcdev)
+{
+ return container_of(lcdev, struct led_classdev_flash, led_cdev);
+}
+
+/**
+ * led_classdev_flash_register - register a new object of led_classdev class
+ with support for flash LEDs
+ * @parent: the flash LED to register
+ * @flash: the led_classdev_flash structure for this device
+ * @node: device tree node of the LED Flash Class device - it must be
+ initialized if the device is to be registered in the flash manager
+ *
+ * Returns: 0 on success or negative error value on failure
+ */
+int led_classdev_flash_register(struct device *parent,
+ struct led_classdev_flash *flash,
+ struct device_node *node);
+
+/**
+ * led_classdev_flash_unregister - unregisters an object of led_classdev class
+ with support for flash LEDs
+ * @flash: the flash LED to unregister
+ *
+ * Unregisters a previously registered via led_classdev_flash_register object
+ */
+void led_classdev_flash_unregister(struct led_classdev_flash *flash);
+
+/**
+ * led_set_flash_strobe - setup flash strobe
+ * @flash: the flash LED to set strobe on
+ * @state: 1 - strobe flash, 0 - stop flash strobe
+ *
+ * Setup flash strobe - trigger flash strobe
+ *
+ * Returns: 0 on success or negative error value on failure
+ */
+extern int led_set_flash_strobe(struct led_classdev_flash *flash,
+ bool state);
+
+/**
+ * led_get_flash_strobe - get flash strobe status
+ * @flash: the flash LED to query
+ * @state: 1 - flash is strobing, 0 - flash is off
+ *
+ * Check whether the flash is strobing at the moment or not.
+ *
+u* Returns: 0 on success or negative error value on failure
+ */
+extern int led_get_flash_strobe(struct led_classdev_flash *flash,
+ bool *state);
+/**
+ * led_set_flash_brightness - set flash LED brightness
+ * @flash: the flash LED to set
+ * @brightness: the brightness to set it to
+ *
+ * Returns: 0 on success or negative error value on failure
+ *
+ * Set a flash LED's brightness.
+ */
+extern int led_set_flash_brightness(struct led_classdev_flash *flash,
+ u32 brightness);
+
+/**
+ * led_update_flash_brightness - update flash LED brightness
+ * @flash: the flash LED to query
+ *
+ * Get a flash LED's current brightness and update led_flash->brightness
+ * member with the obtained value.
+ *
+ * Returns: 0 on success or negative error value on failure
+ */
+extern int led_update_flash_brightness(struct led_classdev_flash *flash);
+
+/**
+ * led_set_flash_timeout - set flash LED timeout
+ * @flash: the flash LED to set
+ * @timeout: the flash timeout to set it to
+ *
+ * Set the flash strobe duration. The duration set by the driver
+ * is returned in the timeout argument and may differ from the
+ * one that was originally passed.
+ *
+ * Returns: 0 on success or negative error value on failure
+ */
+extern int led_set_flash_timeout(struct led_classdev_flash *flash,
+ u32 timeout);
+
+/**
+ * led_get_flash_fault - get the flash LED fault
+ * @flash: the flash LED to query
+ * @fault: bitmask containing flash faults
+ *
+ * Get the flash LED fault.
+ *
+ * Returns: 0 on success or negative error value on failure
+ */
+extern int led_get_flash_fault(struct led_classdev_flash *flash,
+ u32 *fault);
+
+/**
+ * led_set_external_strobe - set the flash LED external_strobe mode
+ * @flash: the flash LED to set
+ * @enable: the state to set it to
+ *
+ * Enable/disable strobing the flash LED with use of external source
+ *
+ Returns: 0 on success or negative error value on failure
+ */
+extern int led_set_external_strobe(struct led_classdev_flash *flash,
+ bool enable);
+
+/**
+ * led_set_indicator_brightness - set indicator LED brightness
+ * @flash: the flash LED to set
+ * @brightness: the brightness to set it to
+ *
+ * Set an indicator LED's brightness.
+ *
+ * Returns: 0 on success or negative error value on failure
+ */
+extern int led_set_indicator_brightness(struct led_classdev_flash *flash,
+ u32 led_brightness);
+
+/**
+ * led_update_indicator_brightness - update flash indicator LED brightness
+ * @flash: the flash LED to query
+ *
+ * Get a flash indicator LED's current brightness and update
+ * led_flash->indicator_brightness member with the obtained value.
+ *
+ * Returns: 0 on success or negative error value on failure
+ */
+extern int led_update_indicator_brightness(struct led_classdev_flash *flash);
+
+
+#endif /* __LINUX_FLASH_LEDS_H_INCLUDED */
diff --git a/include/linux/leds.h b/include/linux/leds.h
index df0715c..8e38eef 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -44,6 +44,8 @@ struct led_classdev {
#define LED_BLINK_INVERT (1 << 19)
#define LED_SYSFS_LOCK (1 << 20)
#define LED_DEV_CAP_TORCH (1 << 21)
+#define LED_DEV_CAP_FLASH (1 << 22)
+#define LED_DEV_CAP_INDICATOR (1 << 23)
/* Set LED brightness level */
/* Must not sleep, use a workqueue if needed */
@@ -82,6 +84,7 @@ struct led_classdev {
unsigned long blink_delay_on, blink_delay_off;
struct delayed_work blink_work;
int blink_brightness;
+ void (*flash_resume)(struct led_classdev *led_cdev);
struct work_struct set_brightness_work;
int delayed_set_value;
--
1.7.9.5
^ permalink raw reply related [flat|nested] 11+ messages in thread