Hi Jacek,
Thanks for the update! Some comments below. I'll try to reply to the rest
during the coming days.
On Fri, Apr 11, 2014 at 04:56:52PM +0200, Jacek Anaszewski wrote:
> 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 and
> optional external_strobe, indicator_brightness and
> max_indicator_btightness. 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.anaszew...@samsung.com>
> Acked-by: Kyungmin Park <kyungmin.p...@samsung.com>
> Cc: Bryan Wu <coolo...@gmail.com>
> Cc: Richard Purdie <rpur...@rpsys.net>
> ---
> drivers/leds/Kconfig | 8 +
> drivers/leds/Makefile | 1 +
> drivers/leds/led-class.c | 36 ++-
> drivers/leds/led-flash.c | 627
> +++++++++++++++++++++++++++++++++++++++++++
> drivers/leds/led-triggers.c | 16 +-
> drivers/leds/leds.h | 6 +
> include/linux/leds.h | 50 +++-
> include/linux/leds_flash.h | 252 +++++++++++++++++
> 8 files changed, 982 insertions(+), 14 deletions(-)
> create mode 100644 drivers/leds/led-flash.c
> create mode 100644 include/linux/leds_flash.h
>
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index 2062682..1e1c81f 100644
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -19,6 +19,14 @@ 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 "Flash LEDs Support"
> + depends on LEDS_CLASS
> + help
> + This option enables support for flash LED devices. Say Y if you
> + want to use flash specific features of a LED device, if they
> + are supported.
> +
> comment "LED drivers"
>
> config LEDS_88PM860X
> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> index 3cd76db..8861b86 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-$(CONFIG_LEDS_CLASS_FLASH) += led-flash.o
> obj-$(CONFIG_LEDS_TRIGGERS) += led-triggers.o
>
> # LED Platform Drivers
> diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
> index f37d63c..58f16c3 100644
> --- a/drivers/leds/led-class.c
> +++ b/drivers/leds/led-class.c
> @@ -9,15 +9,16 @@
> * published by the Free Software Foundation.
> */
>
> -#include <linux/module.h>
> -#include <linux/kernel.h>
> +#include <linux/ctype.h>
> +#include <linux/device.h>
> +#include <linux/err.h>
> #include <linux/init.h>
> +#include <linux/kernel.h>
> #include <linux/list.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> #include <linux/spinlock.h>
> -#include <linux/device.h>
> #include <linux/timer.h>
> -#include <linux/err.h>
> -#include <linux/ctype.h>
> #include <linux/leds.h>
> #include "leds.h"
>
> @@ -45,28 +46,38 @@ 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;
> +
> + mutex_lock(&led_cdev->led_lock);
> +
> + if (led_sysfs_is_locked(led_cdev)) {
> + ret = -EBUSY;
> + goto unlock;
> + }
>
> 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);
> + ret = size;
>
> - return size;
> +unlock:
> + mutex_unlock(&led_cdev->led_lock);
> + return ret;
> }
> static DEVICE_ATTR_RW(brightness);
>
> -static ssize_t led_max_brightness_show(struct device *dev,
> +static ssize_t max_brightness_show(struct device *dev,
> struct device_attribute *attr, char *buf)
> {
> struct led_classdev *led_cdev = dev_get_drvdata(dev);
>
> return sprintf(buf, "%u\n", led_cdev->max_brightness);
> }
> -static DEVICE_ATTR(max_brightness, 0444, led_max_brightness_show, NULL);
> +static DEVICE_ATTR_RO(max_brightness);
>
> #ifdef CONFIG_LEDS_TRIGGERS
> static DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store);
> @@ -174,6 +185,8 @@ 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);
> @@ -218,6 +231,7 @@ 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);
> @@ -271,6 +285,8 @@ 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-flash.c b/drivers/leds/led-flash.c
> new file mode 100644
> index 0000000..9d482a4
> --- /dev/null
> +++ b/drivers/leds/led-flash.c
> @@ -0,0 +1,627 @@
> +/*
> + * LED Class Flash interface
> + *
> + * Copyright (C) 2014 Samsung Electronics Co., Ltd.
> + * Author: Jacek Anaszewski <j.anaszew...@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/module.h>
> +#include <linux/leds.h>
> +#include <linux/leds_flash.h>
> +#include "leds.h"
> +
> +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);
> + 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(led_cdev, 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_flash *flash = led_cdev->flash;
> +
> + /* no lock needed for this */
> + led_update_flash_brightness(led_cdev);
> +
> + 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_flash *flash = led_cdev->flash;
> +
> + 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);
> + 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(led_cdev, 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_flash *flash = led_cdev->flash;
> +
> + /* no lock needed for this */
> + led_update_indicator_brightness(led_cdev);
> +
> + 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_flash *flash = led_cdev->flash;
> +
> + 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);
> + 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;
> +
> + if (state < 0 || state > 1)
> + return -EINVAL;
How about assigning ret and a goto instead? :-)
> + ret = led_set_flash_strobe(led_cdev, 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);
> + int ret;
> +
> + /* no lock needed for this */
> + ret = led_get_flash_strobe(led_cdev);
> + if (ret < 0)
> + return ret;
> +
> + return sprintf(buf, "%u\n", ret);
> +}
> +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);
> + 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(led_cdev, 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_flash *flash = led_cdev->flash;
> +
> + return sprintf(buf, "%d\n", flash->timeout.val);
val is unsigned.
> +}
> +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_flash *flash = led_cdev->flash;
> +
> + return sprintf(buf, "%d\n", flash->timeout.max);
Same here (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);
> + unsigned int fault;
As led_get_flash_fault() expects a u32, it'd be cleaner to use that for
passing a reference.
> + int ret;
> +
> + ret = led_get_flash_fault(led_cdev, &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);
> + 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(led_cdev, 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);
> +
> + return sprintf(buf, "%u\n", led_cdev->flash->external_strobe);
> +}
> +static DEVICE_ATTR_RW(external_strobe);
> +
> +static struct attribute *led_flash_attrs[] = {
> + &dev_attr_flash_brightness.attr,
> + &dev_attr_flash_strobe.attr,
> + &dev_attr_flash_timeout.attr,
> + &dev_attr_max_flash_timeout.attr,
> + &dev_attr_max_flash_brightness.attr,
> + &dev_attr_flash_fault.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_external_strobe_attrs[] = {
> + &dev_attr_external_strobe.attr,
> + NULL,
> +};
> +
> +static struct attribute_group led_flash_group = {
> + .attrs = led_flash_attrs,
> +};
> +
> +static struct attribute_group led_flash_indicator_group = {
> + .attrs = led_flash_indicator_attrs,
> +};
> +
> +static struct attribute_group led_flash_external_strobe_group = {
> + .attrs = led_flash_external_strobe_attrs,
> +};
> +
> +void led_flash_resume(struct led_classdev *led_cdev)
> +{
> + struct led_flash *flash = led_cdev->flash;
> +
> + call_flash_op(brightness_set, led_cdev,
> + flash->brightness.val);
> + call_flash_op(timeout_set, led_cdev,
> + flash->timeout.val);
Both fit on a single line.
> + if (has_flash_op(indicator_brightness_set))
> + call_flash_op(indicator_brightness_set, led_cdev,
> + flash->indicator_brightness->val);
> +}
> +
> +#ifdef CONFIG_V4L2_FLASH
> +static const struct v4l2_flash_ops v4l2_flash_ops = {
> + .brightness_set = led_set_brightness,
> + .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,
> +};
> +#define V4L2_FLASH_OPS (&v4l2_flash_ops)
> +#else
> +#define V4L2_FLASH_OPS NULL
> +#endif
> +
> +
> +void led_flash_remove_sysfs_groups(struct led_classdev *led_cdev)
> +{
> + struct led_flash *flash = led_cdev->flash;
> + 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]);
> +}
> +
> +int led_flash_create_sysfs_groups(struct led_classdev *led_cdev)
> +{
> + struct led_flash *flash = led_cdev->flash;
> + 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_group);
> + if (ret < 0)
> + goto err_create_group;
> + flash->sysfs_groups[num_sysfs_groups++] = &led_flash_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 (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(led_cdev);
> + return ret;
> +}
> +
> +int led_classdev_flash_register(struct device *parent,
> + struct led_classdev *led_cdev)
> +{
> + struct led_flash *flash = led_cdev->flash;
> + const struct led_flash_ops *ops;
> + int ret;
> +
> + if (!flash)
> + return -EINVAL;
> +
> + /* Register led class device */
> + ret = led_classdev_register(parent, led_cdev);
> + if (ret < 0)
> + return ret;
> +
> + if (!flash->has_flash_led)
> + goto exit;
> +
> + /* Validate flash related ops */
> + ops = &flash->ops;
> + if (!ops || !ops->brightness_set || !ops->strobe_set || !ops->strobe_get
> + || !ops->timeout_set || !ops->fault_get)
Could you align the condition to right of the opening parenthese?
The adp1653 cannot tell the strobe status. While the driver is there I think
it's unlikely it'd ever be supported using the LED framework, I think making
strobe_get() optional now isn't necessary. Just FYI; things like this are
out there.
> + return -EINVAL;
> +
> + if (flash->has_external_strobe && !ops->external_strobe_set)
> + return -EINVAL;
> +
> + if (flash->indicator_brightness && !ops->indicator_brightness_set)
> + return -EINVAL;
> +
> + /* Install resume callback for flash controls */
> + led_cdev->flash_resume = led_flash_resume;
> +
> + /* Create flash led specific sysfs attributes */
> + ret = led_flash_create_sysfs_groups(led_cdev);
> + if (ret < 0)
> + goto err_create_groups;
> +
> +exit:
> + /* This will create V4L2 Flash sub-device if it is enabled */
> + ret = v4l2_flash_init(led_cdev, V4L2_FLASH_OPS);
v4l2_flash_init() is only defined in the last patch. I think you need to
split it at least into two so you can have definitions for the LED class
patches that need them.
I think you could also refer to v4l2_flash_ops() directly, and make
v4l2_flash_init() a macro returning zero if CONFIG_V4L2_FLASH isn't defined.
As as result, you wouldn't need to define V4L2_FLASH_OPS.
On the naming of the config option --- as this is directly related to LED
class, what would you think about calling it CONFIG_V4L2_LED_CLASS or
CONFIG_V4L2_FLASH_LED_CLASS, for instance? The same API (but probably not
the implementation) supports also xenon flash devices.
> + if (ret < 0)
> + goto err_create_groups;
What about the sysfs groups?
> +
> + return 0;
> +
> +err_create_groups:
> + led_classdev_unregister(led_cdev);
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(led_classdev_flash_register);
> +
> +void led_classdev_flash_unregister(struct led_classdev *led_cdev)
> +{
> + v4l2_flash_release(led_cdev);
> + led_flash_remove_sysfs_groups(led_cdev);
> + led_classdev_unregister(led_cdev);
> +}
> +EXPORT_SYMBOL_GPL(led_classdev_flash_unregister);
> +
> +/* Caller must ensure led_cdev->led_lock held */
> +void led_sysfs_lock(struct led_classdev *led_cdev)
> +{
How about e.g. WARN_ON(!mutex_is_locked(&led_cdev->led_lock));?
> + led_cdev->flags |= LED_SYSFS_LOCK;
> +}
> +EXPORT_SYMBOL(led_sysfs_lock);
> +
> +/* Caller must ensure led_cdev->led_lock held */
> +void led_sysfs_unlock(struct led_classdev *led_cdev)
> +{
> + led_cdev->flags &= ~LED_SYSFS_LOCK;
> +}
> +EXPORT_SYMBOL(led_sysfs_unlock);
> +
> +int led_set_flash_strobe(struct led_classdev *led_cdev, bool state)
> +{
> + if (!has_flash_op(strobe_set))
> + return -EINVAL;
> +
> + return call_flash_op(strobe_set, led_cdev, state);
> +}
> +EXPORT_SYMBOL(led_set_flash_strobe);
> +
> +int led_get_flash_strobe(struct led_classdev *led_cdev)
> +{
> + if (!has_flash_op(strobe_get))
> + return -EINVAL;
> +
> + return call_flash_op(strobe_get, led_cdev);
> +}
> +EXPORT_SYMBOL(led_get_flash_strobe);
> +
> +void led_clamp_align_val(struct led_ctrl *c)
> +{
> + u32 v, offset;
> +
> + v = c->val + c->step / 2;
> + v = clamp(v, c->min, c->max);
> + offset = v - c->min;
> + offset = c->step * (offset / c->step);
> + c->val = c->min + offset;
> +}
> +
> +int led_set_flash_timeout(struct led_classdev *led_cdev, u32 timeout)
> +{
> + struct led_flash *flash = led_cdev->flash;
> + struct led_ctrl *c = &flash->timeout;
> + int ret = 0;
> +
> + if (!has_flash_op(timeout_set))
> + return -EINVAL;
> +
> + c->val = timeout;
> + led_clamp_align_val(c);
> +
> + if (!(led_cdev->flags & LED_SUSPENDED))
> + ret = call_flash_op(timeout_set, led_cdev, c->val);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL(led_set_flash_timeout);
> +
> +int led_get_flash_fault(struct led_classdev *led_cdev, u32 *fault)
> +{
> + if (!has_flash_op(fault_get))
> + return -EINVAL;
> +
> + return call_flash_op(fault_get, led_cdev, fault);
> +}
> +EXPORT_SYMBOL(led_get_flash_fault);
> +
> +int led_set_external_strobe(struct led_classdev *led_cdev, bool enable)
> +{
> + struct led_flash *flash = led_cdev->flash;
> + int ret;
> +
> + if (!has_flash_op(external_strobe_set))
> + return -EINVAL;
> +
> + if (flash->has_external_strobe) {
> + ret = call_flash_op(external_strobe_set, led_cdev, enable);
> + if (ret < 0)
> + return -EINVAL;
> + flash->external_strobe = enable;
> + } else if (enable)
> + return -EINVAL;
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(led_set_external_strobe);
> +
> +int led_set_flash_brightness(struct led_classdev *led_cdev,
> + u32 brightness)
> +{
> + struct led_flash *flash = led_cdev->flash;
> + struct led_ctrl *c = &flash->brightness;
> + int ret = 0;
> +
> + if (!has_flash_op(brightness_set))
> + return -EINVAL;
> +
> + c->val = brightness;
> + led_clamp_align_val(c);
> +
> + if (!(led_cdev->flags & LED_SUSPENDED))
> + ret = call_flash_op(brightness_set, led_cdev, c->val);
> + return ret;
> +}
> +EXPORT_SYMBOL(led_set_flash_brightness);
> +
> +int led_update_flash_brightness(struct led_classdev *led_cdev)
> +{
> + struct led_flash *flash = led_cdev->flash;
> + struct led_ctrl *c = &flash->brightness;
> + u32 brightness;
> + int ret = 0;
> +
> + if (has_flash_op(brightness_get)) {
> + ret = call_flash_op(brightness_get, led_cdev, &brightness);
> + if (ret < 0)
> + return ret;
> + c->val = brightness;
> + }
> +
> + return ret;
> +}
> +EXPORT_SYMBOL(led_update_flash_brightness);
> +
> +int led_set_indicator_brightness(struct led_classdev *led_cdev,
> + u32 brightness)
> +{
> + struct led_flash *flash = led_cdev->flash;
> + struct led_ctrl *c = flash->indicator_brightness;
> + int ret = 0;
> +
> + if (!has_flash_op(indicator_brightness_set))
> + return -EINVAL;
> +
> + c->val = brightness;
> + led_clamp_align_val(c);
> +
> + if (!(led_cdev->flags & LED_SUSPENDED))
> + ret = call_flash_op(indicator_brightness_set, led_cdev, c->val);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL(led_set_indicator_brightness);
> +
> +int led_update_indicator_brightness(struct led_classdev *led_cdev)
> +{
> + struct led_flash *flash = led_cdev->flash;
> + struct led_ctrl *c = flash->indicator_brightness;
> + u32 brightness;
> + int ret = 0;
> +
> + if (has_flash_op(indicator_brightness_get)) {
> + ret = call_flash_op(indicator_brightness_get, led_cdev,
> + &brightness);
> + if (ret < 0)
> + return ret;
> + c->val = brightness;
> + }
> +
> + return ret;
> +}
> +EXPORT_SYMBOL(led_update_indicator_brightness);
> +
> +static int __init leds_flash_init(void)
> +{
> + return 0;
> +}
> +
> +static void __exit leds_flash_exit(void)
> +{
> +}
> +
> +subsys_initcall(leds_flash_init);
> +module_exit(leds_flash_exit);
> +
> +MODULE_AUTHOR("Jacek Anaszewski <j.anaszew...@samsung.com>");
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("LED Class Flash Interface");
> diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
> index df1a7c1..40e21c0 100644
> --- a/drivers/leds/led-triggers.c
> +++ b/drivers/leds/led-triggers.c
> @@ -37,6 +37,14 @@ 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;
> +
> + 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);
> @@ -47,7 +55,7 @@ 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 +66,14 @@ 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:
> + mutex_unlock(&led_cdev->led_lock);
> + return ret;
> }
> EXPORT_SYMBOL_GPL(led_trigger_store);
>
> diff --git a/drivers/leds/leds.h b/drivers/leds/leds.h
> index 4c50365..f66a0c3 100644
> --- a/drivers/leds/leds.h
> +++ b/drivers/leds/leds.h
> @@ -17,6 +17,12 @@
> #include <linux/rwsem.h>
> #include <linux/leds.h>
>
> +#define call_flash_op(op, args...) \
> + ((led_cdev)->flash->ops.op(args))
> +
> +#define has_flash_op(op) \
> + ((led_cdev)->flash && (led_cdev)->flash->ops.op)
I think you're using the two in a pattern where you first check if the op is
there, and then call it if it is. Could you combine both into
call_flash_op(), and return an error if the op isn't there?
> static inline void __led_set_brightness(struct led_classdev *led_cdev,
> enum led_brightness value)
> {
> diff --git a/include/linux/leds.h b/include/linux/leds.h
> index 0287ab2..a794817 100644
> --- a/include/linux/leds.h
> +++ b/include/linux/leds.h
> @@ -13,12 +13,14 @@
> #define __LINUX_LEDS_H_INCLUDED
>
> #include <linux/list.h>
> -#include <linux/spinlock.h>
> +#include <linux/mutex.h>
> #include <linux/rwsem.h>
> +#include <linux/spinlock.h>
> #include <linux/timer.h>
> #include <linux/workqueue.h>
>
> struct device;
> +struct led_flash;
> /*
> * LED Core
> */
> @@ -29,6 +31,28 @@ enum led_brightness {
> LED_FULL = 255,
> };
>
> +/*
> + * This structure is required in two cases:
> + * - it defines allowed levels of flash leds brightness and timeout
> + * - it provides initialization data for V4L2 Flash controls
> + * when CONFIG_V4L2_FLASH is enabled and allows for proper
> + * enum led_brightness <-> microamperes conversion for the
> + * V4L2_CID_FLASH_TORCH_INTENSITY
> + */
> +struct led_ctrl {
> + /* maximum allowed value */
> + u32 min;
> + /* maximum allowed value */
> + u32 max;
> + /* step value */
> + u32 step;
> + /*
> + * Default value for V4L2 controls and for flash leds
> + * it also serves for caching the value currently set.
> + */
> + u32 val;
> +};
> +
> struct led_classdev {
> const char *name;
> int brightness;
> @@ -42,6 +66,7 @@ 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 << 21)
>
> /* Set LED brightness level */
> /* Must not sleep, use a workqueue if needed */
> @@ -69,6 +94,17 @@ struct led_classdev {
> unsigned long blink_delay_on, blink_delay_off;
> struct timer_list blink_timer;
> int blink_brightness;
> + struct led_flash *flash;
> + void (*flash_resume)(struct led_classdev *led_cdev);
> +#ifdef CONFIG_V4L2_FLASH
> + /* Initialization data for the V4L2_CID_FLASH_TORCH_INTENSITY control */
> + struct led_ctrl brightness_ctrl;
> +#endif
> + /*
> + * Ensures consistent LED sysfs access and protects
> + * LED sysfs locking mechanism
> + */
> + struct mutex led_lock;
>
> struct work_struct set_brightness_work;
> int delayed_set_value;
> @@ -139,6 +175,18 @@ extern void led_blink_set_oneshot(struct led_classdev
> *led_cdev,
> extern void led_set_brightness(struct led_classdev *led_cdev,
> enum led_brightness brightness);
>
> +/**
> + * led_sysfs_is_locked
> + * @led_cdev: the LED to query
> + *
> + * Returns: true if the sysfs interface of the led is disabled,
> + * false otherwise
> + */
> +static inline bool led_sysfs_is_locked(struct led_classdev *led_cdev)
> +{
> + return led_cdev->flags & LED_SYSFS_LOCK;
> +}
> +
> /*
> * LED Triggers
> */
> diff --git a/include/linux/leds_flash.h b/include/linux/leds_flash.h
> new file mode 100644
> index 0000000..0f885a0
> --- /dev/null
> +++ b/include/linux/leds_flash.h
> @@ -0,0 +1,252 @@
> +/*
> + * Flash leds API
> + *
> + * Copyright (C) 2014 Samsung Electronics Co., Ltd.
> + * Author: Jacek Anaszewski <j.anaszew...@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 <media/v4l2-flash.h>
> +#include <linux/leds.h>
"l" comes before "m".
> +/*
> + * Supported led fault bits - must be kept in synch
> + * with V4L2_FLASH_FAULT bits.
> + */
> +#define LED_FAULT_OVER_VOLTAGE (1 << 0)
> +#define LED_FAULT_TIMEOUT (1 << 1)
> +#define LED_FAULT_OVER_TEMPERATURE (1 << 2)
> +#define LED_FAULT_SHORT_CIRCUIT (1 << 3)
> +#define LED_FAULT_OVER_CURRENT (1 << 4)
> +#define LED_FAULT_INDICATOR (1 << 5)
> +#define LED_FAULT_UNDER_VOLTAGE (1 << 6)
> +#define LED_FAULT_INPUT_VOLTAGE (1 << 7)
> +#define LED_FAULT_LED_OVER_TEMPERATURE (1 << 8)
> +
> +#define LED_FLASH_MAX_SYSFS_GROUPS 3
> +
> +struct led_flash_ops {
> + /* set flash brightness */
> + int (*brightness_set)(struct led_classdev *led_cdev,
> + u32 brightness);
> + /* get flash brightness */
> + int (*brightness_get)(struct led_classdev *led_cdev, u32 *brightness);
> + /* set flash indicator brightness */
> + int (*indicator_brightness_set)(struct led_classdev *led_cdev,
> + u32 brightness);
> + /* get flash indicator brightness */
> + int (*indicator_brightness_get)(struct led_classdev *led_cdev,
> + u32 *brightness);
> + /* setup flash strobe */
> + int (*strobe_set)(struct led_classdev *led_cdev,
> + bool state);
> + /* get flash strobe state */
> + int (*strobe_get)(struct led_classdev *led_cdev);
> + /* setup flash timeout */
> + int (*timeout_set)(struct led_classdev *led_cdev,
> + u32 timeout);
Fits on a single line. Applies to some others as well.
> + /* setup strobing the flash from external source */
> + int (*external_strobe_set)(struct led_classdev *led_cdev,
> + bool enable);
> + /* get the flash LED fault */
> + int (*fault_get)(struct led_classdev *led_cdev,
> + u32 *fault);
> +};
> +
> +struct led_flash {
> + /*
> + * 1 - add support for both flash and torch leds,
> + * 0 - handle only torch led
> + */
> + bool has_flash_led;
> + /* 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_ctrl brightness;
> +
> + /* timeout value in microseconds along with its constraints */
> + struct led_ctrl timeout;
> +
> + /*
> + * Indicator brightness value in microamperes along with
> + * its constraints - this is an optional control and must
> + * be allocated by the driver if the device supports privacy
> + * indicator led.
> + */
> + struct led_ctrl *indicator_brightness;
> +
> + /*
> + * determines whether device supports external
> + * flash strobe sources
> + */
> + bool has_external_strobe;
> +
> + /*
> + * If true the device doesn't strobe the flash immediately
> + * after writing 1 to the flash_strobe file, but waits
> + * for an external signal.
> + */
> + bool external_strobe;
> +
> +#ifdef CONFIG_V4L2_FLASH
> + /* V4L2 Flash sub-device data */
> + struct v4l2_flash v4l2_flash;
> +
> + /* flash fault bits that may be set by the device */
> + u32 fault_flags;
> +#endif
> +
> +};
> +
> +/**
> + * led_classdev_flash_register - register a new object of led_classdev class
> + with support for flash LEDs
> + * @parent: the device to register
> + * @led_cdev: the led_classdev structure for this device
> + *
> + * Returns: 0 on success, error code on failure.
> + */
> +int led_classdev_flash_register(struct device *parent,
> + struct led_classdev *led_cdev);
> +
> +/**
> + * led_classdev_flash_unregister - unregisters an object of led_properties
> class
> + with support for flash LEDs
> + * @led_cdev: the flash led device to unregister
> + *
> + * Unregisters a previously registered via led_classdev_flash_register object
> + */
> +void led_classdev_flash_unregister(struct led_classdev *led_cdev);
> +
> +/**
> + * led_set_flash_strobe - setup flash strobe
> + * @led_cdev: 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 *led_cdev, bool state);
> +
> +/**
> + * led_get_flash_strobe - get flash strobe status
> + * @led_cdev: the LED to query
> + *
> + * Check whether the flash is strobing at the moment or not.
> + *
> + * Returns: flash strobe status (0 or 1) on success or negative
> + * error value on failure.
> + */
> +extern int led_get_flash_strobe(struct led_classdev *led_cdev);
> +
> +/**
> + * led_set_flash_brightness - set flash LED brightness
> + * @led_cdev: the LED to set
> + * @brightness: the brightness to set it to
> + *
> + * Returns: 0 on success, -EINVAL on failure
Could this function return other error codes? Same for other functions
below where a specific error code is listed.
> + * Set a flash LED's brightness.
> + */
> +extern int led_set_flash_brightness(struct led_classdev *led_cdev,
> + u32 brightness);
> +
> +/**
> + * led_update_flash_brightness - update flash LED brightness
> + * @led_cdev: 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 *led_cdev);
> +
> +/**
> + * led_set_flash_timeout - set flash LED timeout
> + * @led_cdev: the LED to set
> + * @timeout: the flash timeout to set it to
> + *
> + * Returns: 0 on success, -EINVAL on failure
> + *
> + * 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.
> + */
> +extern int led_set_flash_timeout(struct led_classdev *led_cdev,
> + u32 timeout);
> +
> +/**
> + * led_get_flash_fault - get the flash LED fault
> + * @led_cdev: the LED to query
> + * @fault: bitmask containing flash faults
> + *
> + * Returns: 0 on success, -EINVAL on failure
> + *
> + * Get the flash LED fault.
> + */
> +extern int led_get_flash_fault(struct led_classdev *led_cdev,
> + u32 *fault);
> +
> +/**
> + * led_set_external_strobe - set the flash LED external_strobe mode
> + * @led_cdev: the LED to set
> + * @enable: the state to set it to
> + *
> + * Returns: 0 on success, -EINVAL on failure
> + *
> + * Enable/disable strobing the flash LED with use of external source
> + */
> +extern int led_set_external_strobe(struct led_classdev *led_cdev, bool
> enable);
> +
> +/**
> + * led_set_indicator_brightness - set indicator LED brightness
> + * @led_cdev: the LED to set
> + * @brightness: the brightness to set it to
> + *
> + * Returns: 0 on success, -EINVAL on failure
> + *
> + * Set a flash LED's brightness.
> + */
> +extern int led_set_indicator_brightness(struct led_classdev *led_cdev,
> + u32 led_brightness);
> +
> +/**
> + * led_update_indicator_brightness - update flash indicator LED brightness
> + * @led_cdev: 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 *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);
> +
> +#endif /* __LINUX_FLASH_LEDS_H_INCLUDED */
--
Kind regards,
Sakari Ailus
e-mail: sakari.ai...@iki.fi XMPP: sai...@retiisi.org.uk
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