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Subject[PATCH/RFC v4 08/21] leds: Add sysfs and kernel internal API for flash LEDs
Date
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,
strobe_provider, strobe_providerN, blocking_strobe. 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 | 13 +
drivers/leds/Makefile | 5 +
drivers/leds/led-class-flash.c | 715 ++++++++++++++++++++++++++++++++++
drivers/leds/led-class.c | 4 +
drivers/leds/led-flash-gpio-mux.c | 102 +++++
drivers/leds/led-flash-manager.c | 698 +++++++++++++++++++++++++++++++++
drivers/leds/led-triggers.c | 5 +
drivers/leds/of_led_flash_manager.c | 155 ++++++++
include/linux/led-class-flash.h | 290 ++++++++++++++
include/linux/led-flash-gpio-mux.h | 68 ++++
include/linux/led-flash-manager.h | 121 ++++++
include/linux/leds.h | 4 +
include/linux/of_led_flash_manager.h | 80 ++++
13 files changed, 2260 insertions(+)
create mode 100644 drivers/leds/led-class-flash.c
create mode 100644 drivers/leds/led-flash-gpio-mux.c
create mode 100644 drivers/leds/led-flash-manager.c
create mode 100644 drivers/leds/of_led_flash_manager.c
create mode 100644 include/linux/led-class-flash.h
create mode 100644 include/linux/led-flash-gpio-mux.h
create mode 100644 include/linux/led-flash-manager.h
create mode 100644 include/linux/of_led_flash_manager.h

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 6784c17..5032c6f 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -19,6 +19,19 @@ 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. It allows also for dynamic routing
+ of external strobe signals basing on the information provided
+ in the Device Tree binding. 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 79c5155..237c5ba 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -2,6 +2,11 @@
# LED Core
obj-$(CONFIG_NEW_LEDS) += led-core.o
obj-$(CONFIG_LEDS_CLASS) += led-class.o
+obj-$(CONFIG_LEDS_CLASS_FLASH) += led-flash.o
+led-flash-objs := led-class-flash.o \
+ led-flash-manager.o \
+ led-flash-gpio-mux.o \
+ of_led_flash_manager.o
obj-$(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..607f2d7
--- /dev/null
+++ b/drivers/leds/led-class-flash.c
@@ -0,0 +1,715 @@
+/*
+ * 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/led-flash-manager.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <media/v4l2-flash.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);
+}
+
+#ifdef CONFIG_V4L2_FLASH_LED_CLASS
+const struct v4l2_flash_ops led_flash_v4l2_ops = {
+ .torch_brightness_set = led_set_torch_brightness,
+ .torch_brightness_update = led_update_brightness,
+ .flash_brightness_set = led_set_flash_brightness,
+ .flash_brightness_update = led_update_flash_brightness,
+ .indicator_brightness_set = led_set_indicator_brightness,
+ .indicator_brightness_update = led_update_indicator_brightness,
+ .strobe_set = led_set_flash_strobe,
+ .strobe_get = led_get_flash_strobe,
+ .timeout_set = led_set_flash_timeout,
+ .external_strobe_set = led_set_external_strobe,
+ .fault_get = led_get_flash_fault,
+ .sysfs_lock = led_sysfs_lock,
+ .sysfs_unlock = led_sysfs_unlock,
+};
+
+const struct v4l2_flash_ops *led_get_v4l2_flash_ops(void)
+{
+ return &led_flash_v4l2_ops;
+}
+EXPORT_SYMBOL_GPL(led_get_v4l2_flash_ops);
+#endif
+
+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;
+
+ /* Register in the flash manager if there is related data to parse */
+ if (node) {
+ ret = led_flash_manager_register_flash(flash, node);
+ if (ret < 0)
+ goto err_flash_manager_register;
+ }
+
+ /* 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_flash_manager_unregister_flash(flash);
+err_flash_manager_register:
+ led_classdev_unregister(led_cdev);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(led_classdev_flash_register);
+
+void led_classdev_flash_unregister(struct led_classdev_flash *flash)
+{
+ led_flash_remove_sysfs_groups(flash);
+ led_flash_manager_unregister_flash(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)
+{
+ struct led_classdev *led_cdev = &flash->led_cdev;
+ int ret = 0;
+
+ if (flash->external_strobe)
+ return -EBUSY;
+
+ /* strobe can be stopped without flash manager involvement */
+ if (!state)
+ return call_flash_op(flash, strobe_set, state);
+
+ /*
+ * Flash manager needs to be involved in setting flash
+ * strobe if there were strobe gates defined in the
+ * device tree binding. This call blocks the caller for
+ * the current flash timeout period if state == true and
+ * the flash led device depends on shared muxes. Locking is
+ * required for assuring that nobody will reconfigure muxes
+ * in the meantime.
+ */
+ if ((led_cdev->flags & LED_DEV_CAP_FL_MANAGER))
+ ret = led_flash_manager_setup_strobe(flash, false);
+ else
+ ret = call_flash_op(flash, strobe_set, true);
+
+ return ret;
+}
+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)
+{
+ struct led_classdev *led_cdev = &flash->led_cdev;
+ 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;
+
+ /*
+ * Flash manager needs to be involved in setting external
+ * strobe mode if there were strobe gates defined in the
+ * device tree binding. This call blocks the caller for
+ * the current flash timeout period if enable == true and
+ * the flash led device depends on shared muxes. Locking is
+ * required for assuring that nobody will reconfigure muxes
+ * while the flash device is awaiting external strobe signal.
+ */
+ if (enable && (led_cdev->flags & LED_DEV_CAP_FL_MANAGER)) {
+ ret = led_flash_manager_setup_strobe(flash, true);
+ if (ret < 0)
+ return ret;
+ }
+ } 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 c17dda0..165a1fb 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-flash-gpio-mux.c b/drivers/leds/led-flash-gpio-mux.c
new file mode 100644
index 0000000..2803fcc
--- /dev/null
+++ b/drivers/leds/led-flash-gpio-mux.c
@@ -0,0 +1,102 @@
+/*
+ * LED Flash Class gpio mux
+ *
+ * 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/gpio.h>
+#include <linux/led-flash-gpio-mux.h>
+#include <linux/of_gpio.h>
+#include <linux/slab.h>
+
+int led_flash_gpio_mux_select_line(u32 line_id, void *mux)
+{
+ struct led_flash_gpio_mux *gpio_mux = (struct led_flash_gpio_mux *) mux;
+ struct led_flash_gpio_mux_selector *sel;
+ u32 mask = 1;
+
+ /* Setup selectors */
+ list_for_each_entry(sel, &gpio_mux->selectors, list) {
+ gpio_set_value(sel->gpio, !!(line_id & mask));
+ mask <<= 1;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(led_flash_gpio_mux_select_line);
+
+/* Create standard gpio mux */
+int led_flash_gpio_mux_create(struct led_flash_gpio_mux **new_mux,
+ struct device_node *mux_node)
+{
+ struct led_flash_gpio_mux *mux;
+ struct led_flash_gpio_mux_selector *sel;
+ int gpio_num, gpio, ret, i;
+ char gpio_name[20];
+ static int cnt_gpio;
+
+ /* Get the number of mux selectors */
+ gpio_num = of_gpio_count(mux_node);
+ if (gpio_num == 0)
+ return -EINVAL;
+
+ mux = kzalloc(sizeof(*mux), GFP_KERNEL);
+ if (!mux)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&mux->selectors);
+
+ /* Request gpios for all selectors */
+ for (i = 0; i < gpio_num; ++i) {
+ gpio = of_get_gpio(mux_node, i);
+ if (gpio_is_valid(gpio)) {
+ sprintf(gpio_name, "v4l2_mux selector %d", cnt_gpio++);
+ ret = gpio_request_one(gpio, GPIOF_DIR_OUT, gpio_name);
+ if (ret < 0)
+ goto err_gpio_request;
+
+ /* Add new entry to the gpio selectors list */
+ sel = kzalloc(sizeof(*sel), GFP_KERNEL);
+ if (!sel) {
+ ret = -ENOMEM;
+ goto err_gpio_request;
+ }
+ sel->gpio = gpio;
+
+ list_add_tail(&sel->list, &mux->selectors);
+ } else {
+ ret = -EINVAL;
+ goto err_gpio_request;
+ }
+
+ }
+
+ *new_mux = mux;
+
+ return 0;
+
+err_gpio_request:
+ led_flash_gpio_mux_release(mux);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(led_flash_gpio_mux_create);
+
+void led_flash_gpio_mux_release(void *mux)
+{
+ struct led_flash_gpio_mux *gpio_mux = (struct led_flash_gpio_mux *) mux;
+ struct led_flash_gpio_mux_selector *sel, *n;
+
+ list_for_each_entry_safe(sel, n, &gpio_mux->selectors, list) {
+ if (gpio_is_valid(sel->gpio))
+ gpio_free(sel->gpio);
+ kfree(sel);
+ }
+ kfree(gpio_mux);
+}
+EXPORT_SYMBOL_GPL(led_flash_gpio_mux_release);
diff --git a/drivers/leds/led-flash-manager.c b/drivers/leds/led-flash-manager.c
new file mode 100644
index 0000000..2133277
--- /dev/null
+++ b/drivers/leds/led-flash-manager.c
@@ -0,0 +1,698 @@
+/*
+ * LED Flash Manager for maintaining LED Flash Class devices
+ * along with their corresponding muxex, faciliating dynamic
+ * reconfiguration of the strobe signal source.
+ *
+ * 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/delay.h>
+#include <linux/led-class-flash.h>
+#include <linux/led-flash-gpio-mux.h>
+#include <linux/led-flash-manager.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of_gpio.h>
+#include <linux/of_led_flash_manager.h>
+#include <linux/slab.h>
+
+static LIST_HEAD(flash_list);
+static LIST_HEAD(mux_bound_list);
+static LIST_HEAD(mux_waiting_list);
+static DEFINE_MUTEX(fm_lock);
+
+static ssize_t strobe_provider_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 provider_id;
+ ssize_t ret;
+
+ mutex_lock(&led_cdev->led_lock);
+
+ if (led_sysfs_is_locked(led_cdev)) {
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ ret = kstrtoul(buf, 10, &provider_id);
+ if (ret)
+ goto unlock;
+
+ if (provider_id > flash->num_strobe_providers - 1) {
+ ret = -ERANGE;
+ goto unlock;
+ }
+
+ flash->strobe_provider_id = provider_id;
+
+ ret = size;
+unlock:
+ mutex_unlock(&led_cdev->led_lock);
+ return ret;
+}
+
+static ssize_t strobe_provider_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->strobe_provider_id);
+}
+static DEVICE_ATTR_RW(strobe_provider);
+
+static ssize_t available_strobe_providers_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct led_flash_strobe_provider *provider =
+ container_of(attr, struct led_flash_strobe_provider, attr);
+ const char *no_name = "undefined";
+ const char *provider_name;
+
+ provider_name = provider->name ? provider->name :
+ no_name;
+
+ return sprintf(buf, "%s\n", provider_name);
+}
+
+static ssize_t blocking_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->num_shared_muxes);
+}
+static DEVICE_ATTR_RO(blocking_strobe);
+
+static int led_flash_manager_create_providers_attrs(
+ struct led_classdev_flash *flash)
+{
+ struct led_flash_strobe_provider *provider;
+ struct led_classdev *led_cdev = &flash->led_cdev;
+ int cnt_attr = 0;
+ int ret;
+
+ list_for_each_entry(provider, &flash->strobe_providers, list) {
+ provider->attr.show = available_strobe_providers_show;
+ provider->attr.attr.mode = S_IRUGO;
+
+ sprintf(provider->attr_name, "strobe_provider%d",
+ cnt_attr++);
+ provider->attr.attr.name = provider->attr_name;
+
+ sysfs_attr_init(&provider->attr.attr);
+
+ ret = sysfs_create_file(&led_cdev->dev->kobj,
+ &provider->attr.attr);
+ if (ret < 0)
+ goto error_create_attr;
+
+ provider->attr_registered = true;
+ }
+
+ /*
+ * strobe_provider attribute is required only if there have been more
+ * than one strobe source defined for the LED Flash Class device.
+ */
+ if (cnt_attr > 1) {
+ ret = sysfs_create_file(&led_cdev->dev->kobj,
+ &dev_attr_strobe_provider.attr);
+ if (ret < 0)
+ goto error_create_attr;
+ }
+
+ return 0;
+
+error_create_attr:
+ list_for_each_entry(provider, &flash->strobe_providers, list) {
+ if (!provider->attr_registered)
+ break;
+ sysfs_remove_file(&led_cdev->dev->kobj, &provider->attr.attr);
+ }
+
+ return ret;
+}
+
+static void led_flash_manager_remove_providers_attrs(
+ struct led_classdev_flash *flash)
+{
+ struct led_flash_strobe_provider *provider;
+ struct led_classdev *led_cdev = &flash->led_cdev;
+ int cnt_attr = 0;
+
+ list_for_each_entry(provider, &flash->strobe_providers, list) {
+ if (!provider->attr_registered)
+ break;
+ sysfs_remove_file(&led_cdev->dev->kobj, &provider->attr.attr);
+ provider->attr_registered = false;
+ ++cnt_attr;
+ }
+
+ /*
+ * If there was more than one strobe_providerN attr to remove
+ * than there is also strobe_provider attr to remove.
+ */
+ if (cnt_attr > 1)
+ sysfs_remove_file(&led_cdev->dev->kobj,
+ &dev_attr_strobe_provider.attr);
+}
+
+/* Return mux associated with gate */
+static struct led_flash_mux *led_flash_manager_get_mux_by_gate(
+ struct led_flash_strobe_gate *gate,
+ struct list_head *mux_list)
+{
+ struct led_flash_mux *mux;
+
+ list_for_each_entry(mux, mux_list, list)
+ if (mux->node == gate->mux_node)
+ return mux;
+
+ return NULL;
+}
+
+/* Setup all muxes in the gate list */
+static int led_flash_manager_setup_muxes(struct led_classdev_flash *flash,
+ struct list_head *gate_list)
+{
+ struct led_classdev *led_cdev = &flash->led_cdev;
+ struct led_flash_strobe_gate *gate;
+ struct led_flash_mux *mux;
+ struct device *dev = led_cdev->dev->parent;
+ int ret = 0;
+
+ list_for_each_entry(gate, gate_list, list) {
+ mux = led_flash_manager_get_mux_by_gate(gate, &mux_bound_list);
+ if (!mux) {
+ dev_err(dev, "Flash mux not bound (%s)\n",
+ gate->mux_node->name);
+ return -ENODEV;
+ }
+
+ ret = mux->ops->select_line(gate->line_id,
+ mux->private_data);
+ }
+
+ return ret;
+}
+
+/*
+ * Setup all muxes required to open the route
+ * to the external strobe signal provider
+ */
+static int led_flash_manager_select_strobe_provider(
+ struct led_classdev_flash *flash,
+ int provider_id)
+{
+ struct led_flash_strobe_provider *provider;
+ int ret, provider_cnt = 0;
+
+ list_for_each_entry(provider, &flash->strobe_providers, list)
+ if (provider_cnt++ == provider_id) {
+ ret = led_flash_manager_setup_muxes(flash,
+ &provider->strobe_gates);
+ return ret;
+ }
+
+ return -EINVAL;
+}
+
+/*
+ * Setup all muxes required to open the route
+ * either to software or external strobe source.
+ */
+static int led_flash_manager_set_external_strobe(
+ struct led_classdev_flash *flash,
+ bool external)
+{
+ int ret;
+
+ if (external)
+ ret = led_flash_manager_select_strobe_provider(flash,
+ flash->strobe_provider_id);
+ else
+ ret = led_flash_manager_setup_muxes(flash,
+ &flash->software_strobe_gates);
+
+ return ret;
+}
+
+/* Notify flash manager that async mux is available. */
+int led_flash_manager_bind_async_mux(struct led_flash_mux *async_mux)
+{
+ struct led_flash_mux *mux;
+ bool mux_found = false;
+ int ret = 0;
+
+ if (!async_mux)
+ return -EINVAL;
+
+ mutex_lock(&fm_lock);
+
+ /*
+ * Check whether the LED Flash Class device using this
+ * mux has been already registered in the flash manager.
+ */
+ list_for_each_entry(mux, &mux_waiting_list, list)
+ if (async_mux->node == mux->node) {
+ /* Move the mux to the bound muxes list */
+
+ list_move(&mux->list, &mux_bound_list);
+ mux_found = true;
+
+ if (!try_module_get(async_mux->owner)) {
+ ret = -ENODEV;
+ goto unlock;
+ }
+
+ break;
+ }
+
+ if (!mux_found) {
+ /* This is a new mux - create its representation */
+ mux = kzalloc(sizeof(*mux), GFP_KERNEL);
+ if (!mux) {
+ ret = -ENOMEM;
+ goto unlock;
+ }
+
+ INIT_LIST_HEAD(&mux->refs);
+
+ /* Add the mux to the bound list. */
+ list_add(&mux->list, &mux_bound_list);
+ }
+
+ mux->ops = async_mux->ops;
+ mux->node = async_mux->node;
+ mux->owner = async_mux->owner;
+
+unlock:
+ mutex_unlock(&fm_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(led_flash_manager_bind_async_mux);
+
+int led_flash_manager_unbind_async_mux(struct device_node *mux_node)
+{
+ struct led_flash_mux *mux;
+ int ret = -ENODEV;
+
+ mutex_lock(&fm_lock);
+
+ /*
+ * Mux can be unbound only when is not used by any
+ * flash led device, otherwise this is erroneous call.
+ */
+ list_for_each_entry(mux, &mux_waiting_list, list)
+ if (mux->node == mux_node) {
+ list_move(&mux->list, &mux_waiting_list);
+ ret = 0;
+ break;
+ }
+
+ mutex_unlock(&fm_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(led_flash_manager_unbind_async_mux);
+
+struct led_flash_mux_ops gpio_mux_ops = {
+ .select_line = led_flash_gpio_mux_select_line,
+ .release_private_data = led_flash_gpio_mux_release,
+};
+
+static int __add_mux_ref(struct led_flash_mux_ref *ref,
+ struct led_flash_mux *mux)
+{
+ struct led_flash_mux_ref *r;
+ int ret;
+
+ /*
+ * A flash can be associated with a mux through
+ * more than one gate - increment mux reference
+ * count in such a case.
+ */
+ list_for_each_entry(r, &mux->refs, list)
+ if (r->flash == ref->flash)
+ return 0;
+
+ /* protect async mux against rmmod */
+ if (mux->owner) {
+ ret = try_module_get(mux->owner);
+ if (ret < 0)
+ return ret;
+ }
+
+ list_add(&ref->list, &mux->refs);
+ ++mux->num_refs;
+
+ if (mux->num_refs == 2) {
+ list_for_each_entry(r, &mux->refs, list) {
+ ++r->flash->num_shared_muxes;
+ }
+ return 0;
+ }
+
+ if (mux->num_refs > 2)
+ ++ref->flash->num_shared_muxes;
+
+ return 0;
+}
+
+static void __remove_mux_ref(struct led_flash_mux_ref *ref,
+ struct led_flash_mux *mux)
+{
+ struct led_flash_mux_ref *r;
+
+ /* decrement async mux refcount */
+ if (mux->owner)
+ module_put(mux->owner);
+
+ list_del(&ref->list);
+ --mux->num_refs;
+
+ if (mux->num_refs == 1) {
+ r = list_first_entry(&mux->refs, struct led_flash_mux_ref,
+ list);
+ --r->flash->num_shared_muxes;
+ return;
+ }
+
+ if (mux->num_refs > 1)
+ --ref->flash->num_shared_muxes;
+}
+
+/*
+ * Parse mux node and add the mux it refers to either to waiting
+ * or bound list depending on the mux type (gpio or asynchronous).
+ */
+static int led_flash_manager_parse_mux_node(struct led_classdev_flash *flash,
+ struct led_flash_strobe_gate *gate)
+{
+ struct led_flash_mux *mux;
+ struct device_node *async_mux_node;
+ struct led_flash_gpio_mux *gpio_mux;
+ struct led_flash_mux_ref *ref;
+ int ret = -EINVAL;
+
+ /* Create flash ref to be added to the mux references list */
+ ref = kzalloc(sizeof(*ref), GFP_KERNEL);
+ if (!ref)
+ return -ENOMEM;
+ ref->flash = flash;
+
+ /* if this is async mux update gate's mux_node accordingly */
+ async_mux_node = of_parse_phandle(gate->mux_node, "mux-async", 0);
+ if (async_mux_node)
+ gate->mux_node = async_mux_node;
+
+ /* Check if the mux isn't already on waiting list */
+ list_for_each_entry(mux, &mux_waiting_list, list)
+ if (mux->node == gate->mux_node)
+ return __add_mux_ref(ref, mux);
+
+ /* Check if the mux isn't already on bound list */
+ list_for_each_entry(mux, &mux_bound_list, list)
+ if (mux->node == gate->mux_node)
+ return __add_mux_ref(ref, mux);
+
+ /* This is a new mux - create its representation */
+ mux = kzalloc(sizeof(*mux), GFP_KERNEL);
+ if (!mux)
+ return -ENOMEM;
+
+ mux->node = gate->mux_node;
+
+ INIT_LIST_HEAD(&mux->refs);
+
+ /* Increment reference count */
+ ret = __add_mux_ref(ref, mux);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * Check if this mux has its own driver
+ * or this is standard gpio mux.
+ */
+ if (async_mux_node) {
+ /* Add async mux to the waiting list */
+ list_add(&mux->list, &mux_waiting_list);
+ } else {
+ /* Create default gpio mux */
+ ret = led_flash_gpio_mux_create(&gpio_mux, gate->mux_node);
+ if (ret < 0)
+ goto err_gpio_mux_init;
+
+ /* Register gpio mux device */
+ mux->private_data = gpio_mux;
+ mux->ops = &gpio_mux_ops;
+ list_add(&mux->list, &mux_bound_list);
+ }
+
+ return 0;
+
+err_gpio_mux_init:
+ kfree(mux);
+ kfree(ref);
+
+ return ret;
+}
+
+static void led_flash_manager_release_mux(struct led_flash_mux *mux)
+{
+ if (mux->ops->release_private_data) {
+ if (mux->ops->release_private_data)
+ mux->ops->release_private_data(mux->private_data);
+ list_del(&mux->list);
+ kfree(mux);
+ }
+}
+
+static void led_flash_manager_remove_flash_refs(
+ struct led_classdev_flash *flash)
+{
+ struct led_flash_mux_ref *ref, *rn;
+ struct led_flash_mux *mux, *mn;
+
+ /*
+ * Remove references to the flash from
+ * all the muxes on the list.
+ */
+ list_for_each_entry_safe(mux, mn, &mux_bound_list, list)
+ /* Seek for matching flash ref */
+ list_for_each_entry_safe(ref, rn, &mux->refs, list)
+ if (ref->flash == flash) {
+ /* Decrement reference count */
+ __remove_mux_ref(ref, mux);
+ kfree(ref);
+ /*
+ * Release mux if there are no more
+ * references pointing to it.
+ */
+ if (list_empty(&mux->refs))
+ led_flash_manager_release_mux(mux);
+ }
+}
+
+int led_flash_manager_setup_strobe(struct led_classdev_flash *flash,
+ bool external)
+{
+ u32 flash_timeout = flash->timeout.val / 1000;
+ int ret;
+
+ mutex_lock(&fm_lock);
+
+ /* Setup muxes */
+ ret = led_flash_manager_set_external_strobe(flash, external);
+ if (ret < 0)
+ goto unlock;
+
+ /*
+ * Trigger software strobe under flash manager lock
+ * to make sure that nobody will reconfigure muxes
+ * in the meantime.
+ */
+ if (!external) {
+ ret = flash->ops->strobe_set(flash, true);
+ if (ret < 0)
+ goto unlock;
+ }
+
+ /*
+ * Hold lock for the time of strobing if the
+ * LED Flash Class device depends on shared muxes.
+ */
+ if (flash->num_shared_muxes > 0) {
+ msleep(flash_timeout);
+ /*
+ * external strobe is turned on only for the time of
+ * this call if there are shared muxes involved
+ * in strobe signal routing.
+ */
+ flash->external_strobe = false;
+ }
+
+unlock:
+ mutex_unlock(&fm_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(led_flash_manager_setup_strobe);
+
+int led_flash_manager_create_sysfs_attrs(struct led_classdev_flash *flash)
+{
+ struct led_classdev *led_cdev = &flash->led_cdev;
+ int ret;
+
+ /*
+ * Create sysfs attribtue for indicating if activation of
+ * software or external flash strobe will block the caller.
+ */
+ sysfs_attr_init(&dev_attr_blocking_strobe.attr);
+ ret = sysfs_create_file(&led_cdev->dev->kobj,
+ &dev_attr_blocking_strobe.attr);
+ if (ret < 0)
+ return ret;
+
+ /* Create strobe_providerN attributes */
+ ret = led_flash_manager_create_providers_attrs(flash);
+ if (ret < 0)
+ goto err_create_provider_attrs;
+
+ return 0;
+
+err_create_provider_attrs:
+ sysfs_remove_file(&led_cdev->dev->kobj,
+ &dev_attr_blocking_strobe.attr);
+
+ return ret;
+}
+
+void led_flash_manager_remove_sysfs_attrs(struct led_classdev_flash *flash)
+{
+ struct led_classdev *led_cdev = &flash->led_cdev;
+
+ led_flash_manager_remove_providers_attrs(flash);
+ sysfs_remove_file(&led_cdev->dev->kobj,
+ &dev_attr_blocking_strobe.attr);
+}
+
+int led_flash_manager_register_flash(struct led_classdev_flash *flash,
+ struct device_node *node)
+{
+ struct led_flash_strobe_provider *provider;
+ struct led_flash_strobe_gate *gate;
+ struct led_classdev_flash *fl;
+ struct led_classdev *led_cdev = &flash->led_cdev;
+ int ret = 0;
+
+ if (!flash || !node)
+ return -EINVAL;
+
+ mutex_lock(&fm_lock);
+
+ /* Don't allow to register the same flash more than once */
+ list_for_each_entry(fl, &flash_list, list)
+ if (fl == flash)
+ goto unlock;
+
+ INIT_LIST_HEAD(&flash->software_strobe_gates);
+ INIT_LIST_HEAD(&flash->strobe_providers);
+
+ ret = of_led_flash_manager_parse_dt(flash, node);
+ if (ret < 0)
+ goto unlock;
+
+ /*
+ * Register mux devices declared by the flash device
+ * if they have not been yet known to the flash manager.
+ */
+ list_for_each_entry(gate, &flash->software_strobe_gates, list) {
+ ret = led_flash_manager_parse_mux_node(flash, gate);
+ if (ret < 0)
+ goto err_parse_mux_node;
+ }
+
+ list_for_each_entry(provider, &flash->strobe_providers, list) {
+ list_for_each_entry(gate, &provider->strobe_gates, list) {
+ ret = led_flash_manager_parse_mux_node(flash, gate);
+ if (ret < 0)
+ goto err_parse_mux_node;
+ }
+ ++flash->num_strobe_providers;
+ }
+
+ /*
+ * It doesn't make sense to register in the flash manager
+ * if there are no strobe providers defined.
+ */
+ if (flash->num_strobe_providers == 0)
+ goto unlock;
+
+ led_cdev->flags |= LED_DEV_CAP_FL_MANAGER;
+ flash->has_external_strobe = true;
+ flash->strobe_provider_id = 0;
+
+ ret = led_flash_manager_create_sysfs_attrs(flash);
+ if (ret < 0)
+ goto err_parse_mux_node;
+
+ /* Add flash to the list of flashes maintained by the flash manager. */
+ list_add_tail(&flash->list, &flash_list);
+
+ mutex_unlock(&fm_lock);
+
+ return ret;
+
+err_parse_mux_node:
+ led_flash_manager_remove_flash_refs(flash);
+ of_led_flash_manager_release_dt_data(flash);
+unlock:
+ mutex_unlock(&fm_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(led_flash_manager_register_flash);
+
+void led_flash_manager_unregister_flash(struct led_classdev_flash *flash)
+{
+ struct led_classdev_flash *fl, *n;
+ bool found_flash = false;
+
+ mutex_lock(&fm_lock);
+
+ /* Remove flash from the list, if found */
+ list_for_each_entry_safe(fl, n, &flash_list, list)
+ if (fl == flash) {
+ found_flash = true;
+ break;
+ }
+
+ if (!found_flash)
+ goto unlock;
+
+ list_del(&fl->list);
+
+ led_flash_manager_remove_sysfs_attrs(flash);
+
+ /* Remove all references to the flash */
+ led_flash_manager_remove_flash_refs(flash);
+ of_led_flash_manager_release_dt_data(flash);
+
+unlock:
+ mutex_unlock(&fm_lock);
+}
+EXPORT_SYMBOL_GPL(led_flash_manager_unregister_flash);
+
+MODULE_AUTHOR("Jacek Anaszewski <j.anaszewski@samsung.com>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("LED Flash Manager");
diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
index 0545530..e8380bb 100644
--- a/drivers/leds/led-triggers.c
+++ b/drivers/leds/led-triggers.c
@@ -41,6 +41,11 @@ ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,

mutex_lock(&led_cdev->led_lock);

+ 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/drivers/leds/of_led_flash_manager.c b/drivers/leds/of_led_flash_manager.c
new file mode 100644
index 0000000..d22d853
--- /dev/null
+++ b/drivers/leds/of_led_flash_manager.c
@@ -0,0 +1,155 @@
+/*
+ * LED flash manager of helpers.
+ *
+ * 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/led-class-flash.h>
+#include <linux/of.h>
+#include <linux/of_led_flash_manager.h>
+#include <linux/slab.h>
+
+static int __parse_strobe_gate_node(struct led_classdev_flash *flash,
+ struct device_node *node,
+ struct list_head *gates)
+{
+ struct device_node *mux_node, *subnode;
+ struct led_flash_strobe_gate *gate;
+ struct led_classdev *led_cdev = &flash->led_cdev;
+ u32 line_id;
+ int ret, num_gates = 0;
+
+ /* Get node mux node */
+ mux_node = of_parse_phandle(node, "mux", 0);
+ if (!mux_node)
+ return -EINVAL;
+
+ /* Get the value the mux has to be written to open the gate */
+ ret = of_property_read_u32(node, "mux-line-id", &line_id);
+ if (ret < 0)
+ return ret;
+
+ gate = kzalloc(sizeof(*gate), GFP_KERNEL);
+ if (!gate)
+ return -ENOMEM;
+
+ gate->mux_node = mux_node;
+ gate->line_id = line_id;
+ list_add_tail(&gate->list, gates);
+
+ /* Parse nested gate nodes */
+ for_each_available_child_of_node(node, subnode) {
+ if (!of_node_ncmp(subnode->name, "gate", 4)) {
+ ret = __parse_strobe_gate_node(flash, subnode, gates);
+ if (ret < 0) {
+ dev_dbg(led_cdev->dev->parent,
+ "Failed to parse gate node (%d)\n",
+ ret);
+ goto err_parse_gate;
+ }
+
+ if (++num_gates > 1) {
+ dev_dbg(led_cdev->dev->parent,
+ "Only one available child gate is allowed.\n");
+ ret = -EINVAL;
+ goto err_parse_gate;
+ }
+ }
+ }
+
+ return 0;
+
+err_parse_gate:
+ kfree(gate);
+
+ return ret;
+}
+
+static int __parse_strobe_provider_node(struct led_classdev_flash *flash,
+ struct device_node *node)
+{
+ struct device_node *provider_node;
+ struct led_flash_strobe_provider *provider;
+ int ret;
+
+ /* Create strobe provider representation */
+ provider = kzalloc(sizeof(*provider), GFP_KERNEL);
+ if (!provider)
+ return -ENOMEM;
+
+ /* Get phandle of the device generating strobe source signal */
+ provider_node = of_parse_phandle(node, "strobe-provider", 0);
+
+ /* provider property may be absent */
+ if (provider_node) {
+ /* Use compatible property as a strobe provider name */
+ ret = of_property_read_string(provider_node, "compatible",
+ (const char **) &provider->name);
+ if (ret < 0)
+ goto err_read_name;
+ }
+
+ INIT_LIST_HEAD(&provider->strobe_gates);
+
+ list_add_tail(&provider->list, &flash->strobe_providers);
+
+ ret = __parse_strobe_gate_node(flash, node, &provider->strobe_gates);
+ if (ret < 0)
+ goto err_read_name;
+
+ return 0;
+
+err_read_name:
+ kfree(provider);
+
+ return ret;
+}
+
+int of_led_flash_manager_parse_dt(struct led_classdev_flash *flash,
+ struct device_node *node)
+{
+ struct device_node *subnode;
+ int ret;
+
+ for_each_available_child_of_node(node, subnode) {
+ if (!of_node_cmp(subnode->name, "gate-software-strobe")) {
+ ret = __parse_strobe_gate_node(flash, subnode,
+ &flash->software_strobe_gates);
+ if (ret < 0)
+ return ret;
+ }
+ if (!of_node_ncmp(subnode->name, "gate-external-strobe", 20)) {
+ ret = __parse_strobe_provider_node(flash, subnode);
+ if (ret < 0)
+ return ret;
+ }
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(of_led_flash_manager_parse_dt);
+
+void of_led_flash_manager_release_dt_data(struct led_classdev_flash *flash)
+{
+ struct list_head *gate_list;
+ struct led_flash_strobe_gate *gate, *gn;
+ struct led_flash_strobe_provider *provider, *sn;
+
+ gate_list = &flash->software_strobe_gates;
+ list_for_each_entry_safe(gate, gn, gate_list, list)
+ kfree(gate);
+
+ list_for_each_entry_safe(provider, sn, &flash->strobe_providers, list) {
+ list_for_each_entry_safe(gate, gn, &provider->strobe_gates,
+ list)
+ kfree(gate);
+ kfree(provider);
+ }
+}
+EXPORT_SYMBOL_GPL(of_led_flash_manager_release_dt_data);
diff --git a/include/linux/led-class-flash.h b/include/linux/led-class-flash.h
new file mode 100644
index 0000000..6ed7e8a
--- /dev/null
+++ b/include/linux/led-class-flash.h
@@ -0,0 +1,290 @@
+/*
+ * 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 v4l2_flash_ops;
+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;
+
+ /*
+ * number of muxes that this device shares
+ * with other LED Flash Class devices.
+ */
+ int num_shared_muxes;
+};
+
+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_flash class
+ with support for flash LEDs
+ * @parent: the device 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_flash class
+ with support for flash LEDs
+ * @flash: the flash led device 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 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 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 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 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 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 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 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 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);
+
+#ifdef CONFIG_V4L2_FLASH_LED_CLASS
+/**
+ * led_get_v4l2_flash_ops - get ops for controlling LED Flash Class
+ device with use of V4L2 Flash controls
+ * Returns: v4l2_flash_ops
+ */
+const struct v4l2_flash_ops *led_get_v4l2_flash_ops(void);
+#else
+#define led_get_v4l2_flash_ops() (0)
+#endif
+
+#endif /* __LINUX_FLASH_LEDS_H_INCLUDED */
diff --git a/include/linux/led-flash-gpio-mux.h b/include/linux/led-flash-gpio-mux.h
new file mode 100644
index 0000000..c56d38f
--- /dev/null
+++ b/include/linux/led-flash-gpio-mux.h
@@ -0,0 +1,68 @@
+/*
+ * LED Flash Class gpio mux
+ *
+ * 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 _LED_FLASH_GPIO_MUX_H
+#define _LED_FLASH_GPIO_MUX_H
+
+struct device_node;
+
+struct list_head;
+
+/**
+ * struct led_flash_gpio_mux_selector - element of gpio mux selectors list
+ * @list: links mux selectors
+ * @gpio: mux selector gpio
+ */
+struct led_flash_gpio_mux_selector {
+ struct list_head list;
+ int gpio;
+};
+
+/**
+ * struct led_flash_gpio_mux - gpio mux
+ * @selectors: mux selectors
+ */
+struct led_flash_gpio_mux {
+ struct list_head selectors;
+};
+
+/**
+ * led_flash_gpio_mux_create - create gpio mux
+ * @new_mux: created mux
+ * @mux_node: device tree node with gpio definitions
+ *
+ * Create V4L2 subdev wrapping given LED subsystem device.
+ *
+ * Returns: 0 on success or negative error value on failure
+ */
+int led_flash_gpio_mux_create(struct led_flash_gpio_mux **new_mux,
+ struct device_node *mux_node);
+
+/**
+ * led_flash_gpio_mux_release - release gpio mux
+ * @gpio_mux: mux to be released
+ *
+ * Create V4L2 subdev wrapping given LED subsystem device.
+ */
+void led_flash_gpio_mux_release(void *gpio_mux);
+
+/**
+ * led_flash_gpio_mux_select_line - select mux line
+ * @line_id: id of the line to be selected
+ * @mux: mux to be set
+ *
+ * Create V4L2 subdev wrapping given LED subsystem device.
+ *
+ * Returns: 0 on success or negative error value on failure
+ */
+int led_flash_gpio_mux_select_line(u32 line_id, void *mux);
+
+#endif /* _LED_FLASH_GPIO_MUX_H */
diff --git a/include/linux/led-flash-manager.h b/include/linux/led-flash-manager.h
new file mode 100644
index 0000000..174eedb
--- /dev/null
+++ b/include/linux/led-flash-manager.h
@@ -0,0 +1,121 @@
+/*
+ * LED Flash Manager for maintaining LED Flash Class devices
+ * along with their corresponding muxes that faciliate dynamic
+ * reconfiguration of the strobe signal source.
+ *
+ * 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 _LED_FLASH_MANAGER_H
+#define _LED_FLASH_MANAGER_H
+
+#include <linux/types.h>
+
+struct list_head;
+
+struct led_flash_mux_ops {
+ /* select mux line */
+ int (*select_line)(u32 line_id, void *mux);
+ /*
+ * release private mux data - it is intended for gpio muxes
+ * only and mustn't be initialized by asynchronous muxes.
+ */
+ void (*release_private_data)(void *mux);
+};
+
+/**
+ * struct led_flash_mux_ref - flash mux reference
+ * @list: links flashes pointing to a mux
+ * @flash: flash holding a mux reference
+ */
+struct led_flash_mux_ref {
+ struct list_head list;
+ struct led_classdev_flash *flash;
+};
+
+/**
+ * struct led_flash_mux - flash mux used for routing strobe signal
+ * @list: list of muxes declared by registered flashes
+ * @node: mux Device Tree node
+ * @private_data: mux internal data
+ * @ops: ops facilitating mux state manipulation
+ * @refs: list of flashes using the mux
+ * @num_refs: number of flashes using the mux
+ * @owner: module owning an async mux driver
+ */
+struct led_flash_mux {
+ struct list_head list;
+ struct device_node *node;
+ void *private_data;
+ struct led_flash_mux_ops *ops;
+ struct list_head refs;
+ int num_refs;
+ struct module *owner;
+};
+
+/**
+ * led_flash_manager_setup_strobe - setup flash strobe
+ * @flash: the LED Flash Class device to strobe
+ * @external: true - setup external strobe,
+ * false - setup software strobe
+ *
+ * Configure muxes to route relevant strobe signals to the
+ * flash led device and strobe the flash if software strobe
+ * is to be activated. If the flash device depends on shared
+ * muxes the caller is blocked for the flash_timeout period.
+ *
+ * Returns: 0 on success or negative error value on failure.
+ */
+int led_flash_manager_setup_strobe(struct led_classdev_flash *flash,
+ bool external);
+
+/**
+ * led_flash_manager_bind_async_mux - bind asynchronous mulitplexer
+ * @async_mux: mux registration data
+ *
+ * Notify the flash manager that an asychronous mux has been probed.
+ *
+ * Returns: 0 on success or negative error value on failure.
+ */
+int led_flash_manager_bind_async_mux(struct led_flash_mux *async_mux);
+
+/**
+ * led_flash_manager_unbind_async_mux - unbind asynchronous mulitplexer
+ * @mux_node: device node of the mux to be unbound
+ *
+ * Notify the flash manager that an asychronous mux has been removed.
+ *
+ * Returns: 0 on success or negative error value on failure.
+ */
+int led_flash_manager_unbind_async_mux(struct device_node *mux_node);
+
+/**
+ * led_flash_manager_register_flash - register LED Flash Class device
+ in the flash manager
+ * @flash: the LED Flash Class device to be registered
+ * @node: Device Tree node - it is expected to contain information
+ * about strobe signal topology
+ *
+ * Register LED Flash Class device and retrieve information
+ * about related strobe signals topology.
+ *
+ * Returns: 0 on success or negative error value on failure.
+ */
+int led_flash_manager_register_flash(struct led_classdev_flash *flash,
+ struct device_node *node);
+
+/**
+ * led_flash_manager_unregister_flash - unregister LED Flash Class device
+ * from the flash manager
+ * @flash: the LED Flash Class device to be unregistered
+ *
+ * Unregister LED Flash Class device from the flash manager.
+ */
+void led_flash_manager_unregister_flash(struct led_classdev_flash *flash);
+
+#endif /* _LED_FLASH_MANAGER_H */
diff --git a/include/linux/leds.h b/include/linux/leds.h
index 9bea9e6..1f12d36 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -45,6 +45,9 @@ 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)
+#define LED_DEV_CAP_FL_MANAGER (1 << 24)

/* Set LED brightness level */
/* Must not sleep, use a workqueue if needed */
@@ -83,6 +86,7 @@ struct led_classdev {
unsigned long blink_delay_on, blink_delay_off;
struct timer_list blink_timer;
int blink_brightness;
+ void (*flash_resume)(struct led_classdev *led_cdev);

struct work_struct set_brightness_work;
int delayed_set_value;
diff --git a/include/linux/of_led_flash_manager.h b/include/linux/of_led_flash_manager.h
new file mode 100644
index 0000000..d27cb46
--- /dev/null
+++ b/include/linux/of_led_flash_manager.h
@@ -0,0 +1,80 @@
+/*
+ * LED flash manager of helpers.
+ *
+ * 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 _OF_LED_FLASH_MANAGER_H
+#define _OF_LED_FLASH_MANAGER_H
+
+#include <linux/sysfs.h>
+#include <linux/device.h>
+
+struct led_classdev_flash;
+struct device_node;
+struct list_head;
+
+#define MAX_ATTR_NAME 18 /* allows for strobe providers ids up to 999 */
+
+/**
+ * struct led_flash_strobe_gate - strobe signal gate
+ * @list: links gates
+ * @mux_node: gate's parent mux
+ * @line_id: id of a mux line that the gate represents
+ */
+struct led_flash_strobe_gate {
+ struct list_head list;
+ struct device_node *mux_node;
+ u32 line_id;
+};
+
+/**
+ * struct led_flash_strobe_provider - external strobe signal provider that
+ may be associated with the flash device
+ * @list: links strobe providers
+ * @strobe_gates: list of gates that route strobe signal
+ from the strobe provider to the flash device
+ * @node: device node of the strobe provider device
+ */
+struct led_flash_strobe_provider {
+ struct list_head list;
+ struct list_head strobe_gates;
+ const char *name;
+ struct device_attribute attr;
+ char attr_name[MAX_ATTR_NAME];
+ bool attr_registered;
+};
+
+/**
+ * of_led_flash_manager_parse_dt - parse flash manager data of
+ * a LED Flash Class device DT node
+ *
+ * @flash: the LED Flash Class device to store the parsed data in
+ * @node: device node to parse
+ *
+ * Parse the multiplexers' settings that need to be applied for
+ * opening a route to all the flash strobe signals available for
+ * the device.
+ *
+ * Returns: 0 on success or negative error value on failure
+ */
+int of_led_flash_manager_parse_dt(struct led_classdev_flash *flash,
+ struct device_node *node);
+
+
+/**
+ * of_led_flash_manager_release_dt_data - release parsed DT data
+ *
+ * @flash: the LED Flash Class device to release data from
+ *
+ * Release data structures containing information about strobe
+ * source routes available for the device.
+ */
+void of_led_flash_manager_release_dt_data(struct led_classdev_flash *flash);
+
+#endif /* _OF_LED_FLASH_MANAGER_H */
--
1.7.9.5


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