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authorJacek Anaszewski <j.anaszewski@samsung.com>2015-01-09 18:22:51 +0300
committerBryan Wu <cooloney@gmail.com>2015-01-27 01:59:08 +0300
commit7aea8389a77abf9fde254aca2434a605c7704f58 (patch)
tree580f35fdeca75a9533329d85822ab32f89fce64a /drivers/leds/led-class-flash.c
parent452bc149947bb31775f0dc6a637fcf792af88e60 (diff)
downloadlinux-7aea8389a77abf9fde254aca2434a605c7704f58.tar.xz
leds: Add LED Flash class extension to the LED subsystem
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, flash_sync_strobe and available_sync_leds. 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: Richard Purdie <rpurdie@rpsys.net> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Bryan Wu <cooloney@gmail.com>
Diffstat (limited to 'drivers/leds/led-class-flash.c')
-rw-r--r--drivers/leds/led-class-flash.c486
1 files changed, 486 insertions, 0 deletions
diff --git a/drivers/leds/led-class-flash.c b/drivers/leds/led-class-flash.c
new file mode 100644
index 000000000000..4a19fd44f93f
--- /dev/null
+++ b/drivers/leds/led-class-flash.c
@@ -0,0 +1,486 @@
+/*
+ * LED Flash class interface
+ *
+ * Copyright (C) 2015 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/led-class-flash.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include "leds.h"
+
+#define has_flash_op(fled_cdev, op) \
+ (fled_cdev && fled_cdev->ops->op)
+
+#define call_flash_op(fled_cdev, op, args...) \
+ ((has_flash_op(fled_cdev, op)) ? \
+ (fled_cdev->ops->op(fled_cdev, args)) : \
+ -EINVAL)
+
+static const char * const led_flash_fault_names[] = {
+ "led-over-voltage",
+ "flash-timeout-exceeded",
+ "controller-over-temperature",
+ "controller-short-circuit",
+ "led-power-supply-over-current",
+ "indicator-led-fault",
+ "led-under-voltage",
+ "controller-under-voltage",
+ "led-over-temperature",
+};
+
+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 *fled_cdev = lcdev_to_flcdev(led_cdev);
+ unsigned long state;
+ ssize_t ret;
+
+ mutex_lock(&led_cdev->led_access);
+
+ if (led_sysfs_is_disabled(led_cdev)) {
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ ret = kstrtoul(buf, 10, &state);
+ if (ret)
+ goto unlock;
+
+ ret = led_set_flash_brightness(fled_cdev, state);
+ if (ret < 0)
+ goto unlock;
+
+ ret = size;
+unlock:
+ mutex_unlock(&led_cdev->led_access);
+ 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 *fled_cdev = lcdev_to_flcdev(led_cdev);
+
+ /* no lock needed for this */
+ led_update_flash_brightness(fled_cdev);
+
+ return sprintf(buf, "%u\n", fled_cdev->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 *fled_cdev = lcdev_to_flcdev(led_cdev);
+
+ return sprintf(buf, "%u\n", fled_cdev->brightness.max);
+}
+static DEVICE_ATTR_RO(max_flash_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 *fled_cdev = lcdev_to_flcdev(led_cdev);
+ unsigned long state;
+ ssize_t ret = -EINVAL;
+
+ mutex_lock(&led_cdev->led_access);
+
+ if (led_sysfs_is_disabled(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(fled_cdev, state);
+ if (ret < 0)
+ goto unlock;
+ ret = size;
+unlock:
+ mutex_unlock(&led_cdev->led_access);
+ 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 *fled_cdev = lcdev_to_flcdev(led_cdev);
+ bool state;
+ int ret;
+
+ /* no lock needed for this */
+ ret = led_get_flash_strobe(fled_cdev, &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 *fled_cdev = lcdev_to_flcdev(led_cdev);
+ unsigned long flash_timeout;
+ ssize_t ret;
+
+ mutex_lock(&led_cdev->led_access);
+
+ if (led_sysfs_is_disabled(led_cdev)) {
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ ret = kstrtoul(buf, 10, &flash_timeout);
+ if (ret)
+ goto unlock;
+
+ ret = led_set_flash_timeout(fled_cdev, flash_timeout);
+ if (ret < 0)
+ goto unlock;
+
+ ret = size;
+unlock:
+ mutex_unlock(&led_cdev->led_access);
+ 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 *fled_cdev = lcdev_to_flcdev(led_cdev);
+
+ return sprintf(buf, "%u\n", fled_cdev->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 *fled_cdev = lcdev_to_flcdev(led_cdev);
+
+ return sprintf(buf, "%u\n", fled_cdev->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 *fled_cdev = lcdev_to_flcdev(led_cdev);
+ u32 fault, mask = 0x1;
+ char *pbuf = buf;
+ int i, ret, buf_len;
+
+ ret = led_get_flash_fault(fled_cdev, &fault);
+ if (ret < 0)
+ return -EINVAL;
+
+ *buf = '\0';
+
+ for (i = 0; i < LED_NUM_FLASH_FAULTS; ++i) {
+ if (fault & mask) {
+ buf_len = sprintf(pbuf, "%s ",
+ led_flash_fault_names[i]);
+ pbuf += buf_len;
+ }
+ mask <<= 1;
+ }
+
+ return sprintf(buf, "%s\n", buf);
+}
+static DEVICE_ATTR_RO(flash_fault);
+
+static ssize_t available_sync_leds_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
+ char *pbuf = buf;
+ int i, buf_len;
+
+ buf_len = sprintf(pbuf, "[0: none] ");
+ pbuf += buf_len;
+
+ for (i = 0; i < fled_cdev->num_sync_leds; ++i) {
+ buf_len = sprintf(pbuf, "[%d: %s] ", i + 1,
+ fled_cdev->sync_leds[i]->led_cdev.name);
+ pbuf += buf_len;
+ }
+
+ return sprintf(buf, "%s\n", buf);
+}
+static DEVICE_ATTR_RO(available_sync_leds);
+
+static ssize_t flash_sync_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 *fled_cdev = lcdev_to_flcdev(led_cdev);
+ unsigned long led_id;
+ ssize_t ret;
+
+ mutex_lock(&led_cdev->led_access);
+
+ if (led_sysfs_is_disabled(led_cdev)) {
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ ret = kstrtoul(buf, 10, &led_id);
+ if (ret)
+ goto unlock;
+
+ if (led_id > fled_cdev->num_sync_leds) {
+ ret = -ERANGE;
+ goto unlock;
+ }
+
+ fled_cdev->sync_led_id = led_id;
+
+ ret = size;
+unlock:
+ mutex_unlock(&led_cdev->led_access);
+ return ret;
+}
+
+static ssize_t flash_sync_strobe_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
+ int sled_id = fled_cdev->sync_led_id;
+ char *sync_led_name = "none";
+
+ if (fled_cdev->sync_led_id > 0)
+ sync_led_name = (char *)
+ fled_cdev->sync_leds[sled_id - 1]->led_cdev.name;
+
+ return sprintf(buf, "[%d: %s]\n", sled_id, sync_led_name);
+}
+static DEVICE_ATTR_RW(flash_sync_strobe);
+
+static struct attribute *led_flash_strobe_attrs[] = {
+ &dev_attr_flash_strobe.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_fault_attrs[] = {
+ &dev_attr_flash_fault.attr,
+ NULL,
+};
+
+static struct attribute *led_flash_sync_strobe_attrs[] = {
+ &dev_attr_available_sync_leds.attr,
+ &dev_attr_flash_sync_strobe.attr,
+ NULL,
+};
+
+static const struct attribute_group led_flash_strobe_group = {
+ .attrs = led_flash_strobe_attrs,
+};
+
+static const struct attribute_group led_flash_timeout_group = {
+ .attrs = led_flash_timeout_attrs,
+};
+
+static const struct attribute_group led_flash_brightness_group = {
+ .attrs = led_flash_brightness_attrs,
+};
+
+static const struct attribute_group led_flash_fault_group = {
+ .attrs = led_flash_fault_attrs,
+};
+
+static const struct attribute_group led_flash_sync_strobe_group = {
+ .attrs = led_flash_sync_strobe_attrs,
+};
+
+static void led_flash_resume(struct led_classdev *led_cdev)
+{
+ struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
+
+ call_flash_op(fled_cdev, flash_brightness_set,
+ fled_cdev->brightness.val);
+ call_flash_op(fled_cdev, timeout_set, fled_cdev->timeout.val);
+}
+
+static void led_flash_init_sysfs_groups(struct led_classdev_flash *fled_cdev)
+{
+ struct led_classdev *led_cdev = &fled_cdev->led_cdev;
+ const struct led_flash_ops *ops = fled_cdev->ops;
+ const struct attribute_group **flash_groups = fled_cdev->sysfs_groups;
+
+ int num_sysfs_groups = 0;
+
+ flash_groups[num_sysfs_groups++] = &led_flash_strobe_group;
+
+ if (ops->flash_brightness_set)
+ flash_groups[num_sysfs_groups++] = &led_flash_brightness_group;
+
+ if (ops->timeout_set)
+ flash_groups[num_sysfs_groups++] = &led_flash_timeout_group;
+
+ if (ops->fault_get)
+ flash_groups[num_sysfs_groups++] = &led_flash_fault_group;
+
+ if (led_cdev->flags & LED_DEV_CAP_SYNC_STROBE)
+ flash_groups[num_sysfs_groups++] = &led_flash_sync_strobe_group;
+
+ led_cdev->groups = flash_groups;
+}
+
+int led_classdev_flash_register(struct device *parent,
+ struct led_classdev_flash *fled_cdev)
+{
+ struct led_classdev *led_cdev;
+ const struct led_flash_ops *ops;
+ int ret;
+
+ if (!fled_cdev)
+ return -EINVAL;
+
+ led_cdev = &fled_cdev->led_cdev;
+
+ if (led_cdev->flags & LED_DEV_CAP_FLASH) {
+ if (!led_cdev->brightness_set_sync)
+ return -EINVAL;
+
+ ops = fled_cdev->ops;
+ if (!ops || !ops->strobe_set)
+ return -EINVAL;
+
+ led_cdev->flash_resume = led_flash_resume;
+
+ /* Select the sysfs attributes to be created for the device */
+ led_flash_init_sysfs_groups(fled_cdev);
+ }
+
+ /* Register led class device */
+ ret = led_classdev_register(parent, led_cdev);
+ if (ret < 0)
+ return ret;
+
+ /* Setting a torch brightness needs to have immediate effect */
+ led_cdev->flags &= ~SET_BRIGHTNESS_ASYNC;
+ led_cdev->flags |= SET_BRIGHTNESS_SYNC;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(led_classdev_flash_register);
+
+void led_classdev_flash_unregister(struct led_classdev_flash *fled_cdev)
+{
+ if (!fled_cdev)
+ return;
+
+ led_classdev_unregister(&fled_cdev->led_cdev);
+}
+EXPORT_SYMBOL_GPL(led_classdev_flash_unregister);
+
+static 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 *fled_cdev, u32 timeout)
+{
+ struct led_classdev *led_cdev = &fled_cdev->led_cdev;
+ struct led_flash_setting *s = &fled_cdev->timeout;
+
+ s->val = timeout;
+ led_clamp_align(s);
+
+ if (!(led_cdev->flags & LED_SUSPENDED))
+ return call_flash_op(fled_cdev, timeout_set, s->val);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(led_set_flash_timeout);
+
+int led_get_flash_fault(struct led_classdev_flash *fled_cdev, u32 *fault)
+{
+ return call_flash_op(fled_cdev, fault_get, fault);
+}
+EXPORT_SYMBOL_GPL(led_get_flash_fault);
+
+int led_set_flash_brightness(struct led_classdev_flash *fled_cdev,
+ u32 brightness)
+{
+ struct led_classdev *led_cdev = &fled_cdev->led_cdev;
+ struct led_flash_setting *s = &fled_cdev->brightness;
+
+ s->val = brightness;
+ led_clamp_align(s);
+
+ if (!(led_cdev->flags & LED_SUSPENDED))
+ return call_flash_op(fled_cdev, flash_brightness_set, s->val);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(led_set_flash_brightness);
+
+int led_update_flash_brightness(struct led_classdev_flash *fled_cdev)
+{
+ struct led_flash_setting *s = &fled_cdev->brightness;
+ u32 brightness;
+
+ if (has_flash_op(fled_cdev, flash_brightness_get)) {
+ int ret = call_flash_op(fled_cdev, flash_brightness_get,
+ &brightness);
+ if (ret < 0)
+ return ret;
+
+ s->val = brightness;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(led_update_flash_brightness);
+
+MODULE_AUTHOR("Jacek Anaszewski <j.anaszewski@samsung.com>");
+MODULE_DESCRIPTION("LED Flash class interface");
+MODULE_LICENSE("GPL v2");