[PATCH/RFC v8 06/14] media: Add registration helpers for V4L2 flash sub-devices

Jacek Anaszewski
2014-11-28T09:19:56Z

This patch adds helper functions for registering/unregistering
LED Flash class devices as V4L2 sub-devices. The functions should
be called from the LED subsystem device driver. In case the
support for V4L2 Flash sub-devices is disabled in the kernel
config the functions' empty versions will be used.

Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Sakari Ailus <sakari.ailus@iki.fi>
Cc: Hans Verkuil <hans.verkuil@cisco.com>
---
drivers/media/v4l2-core/Kconfig | 11 +
drivers/media/v4l2-core/Makefile | 2 +
drivers/media/v4l2-core/v4l2-flash.c | 516 ++++++++++++++++++++++++++++++++++
include/media/v4l2-flash.h | 138 +++++++++
4 files changed, 667 insertions(+)
create mode 100644 drivers/media/v4l2-core/v4l2-flash.c
create mode 100644 include/media/v4l2-flash.h

diff --git a/drivers/media/v4l2-core/Kconfig b/drivers/media/v4l2-core/Kconfig
index ba7e21a..f034f1a 100644
--- a/drivers/media/v4l2-core/Kconfig
+++ b/drivers/media/v4l2-core/Kconfig
@@ -44,6 +44,17 @@ config V4L2_MEM2MEM_DEV
tristate
depends on VIDEOBUF2_CORE

+# Used by LED subsystem flash drivers
+config V4L2_FLASH_LED_CLASS
+ tristate "Enable support for Flash sub-devices"
+ depends on VIDEO_V4L2_SUBDEV_API
+ depends on LEDS_CLASS_FLASH
+ ---help---
+ Say Y here to enable support for Flash sub-devices, which allow
+ to control LED class devices with use of V4L2 Flash controls.
+
+ When in doubt, say N.
+
# Used by drivers that need Videobuf modules
config VIDEOBUF_GEN
tristate
diff --git a/drivers/media/v4l2-core/Makefile b/drivers/media/v4l2-core/Makefile
index 63d29f2..44e858c 100644
--- a/drivers/media/v4l2-core/Makefile
+++ b/drivers/media/v4l2-core/Makefile
@@ -22,6 +22,8 @@ obj-$(CONFIG_VIDEO_TUNER) += tuner.o

obj-$(CONFIG_V4L2_MEM2MEM_DEV) += v4l2-mem2mem.o

+obj-$(CONFIG_V4L2_FLASH_LED_CLASS) += v4l2-flash.o
+
obj-$(CONFIG_VIDEOBUF_GEN) += videobuf-core.o
obj-$(CONFIG_VIDEOBUF_DMA_SG) += videobuf-dma-sg.o
obj-$(CONFIG_VIDEOBUF_DMA_CONTIG) += videobuf-dma-contig.o
diff --git a/drivers/media/v4l2-core/v4l2-flash.c b/drivers/media/v4l2-core/v4l2-flash.c
new file mode 100644
index 0000000..f5075b0
--- /dev/null
+++ b/drivers/media/v4l2-core/v4l2-flash.c
@@ -0,0 +1,516 @@
+/*
+ * V4L2 Flash LED sub-device registration 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/led-class-flash.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <media/v4l2-flash.h>
+
+#define has_flash_op(v4l2_flash, op) \
+ (v4l2_flash && v4l2_flash->ops->op)
+
+#define call_flash_op(v4l2_flash, op, args...) \
+ (has_flash_op(v4l2_flash, op) ? \
+ v4l2_flash->ops->op(args) : \
+ -EINVAL)
+
+static inline enum led_brightness v4l2_flash_intensity_to_led_brightness(
+ struct v4l2_ctrl *ctrl,
+ s32 intensity)
+{
+ s64 __intensity = intensity - ctrl->minimum;
+
+ do_div(__intensity, ctrl->step);
+
+ return __intensity + 1;
+}
+
+static inline s32 v4l2_flash_led_brightness_to_intensity(
+ struct v4l2_ctrl *ctrl,
+ enum led_brightness brightness)
+{
+ return ((brightness - 1) * ctrl->step) + ctrl->minimum;
+}
+
+static int v4l2_flash_g_volatile_ctrl(struct v4l2_ctrl *c)
+{
+ struct v4l2_flash *v4l2_flash = v4l2_ctrl_to_v4l2_flash(c);
+ struct led_classdev_flash *flash = v4l2_flash->flash;
+ struct led_classdev *led_cdev = &flash->led_cdev;
+ struct v4l2_ctrl **ctrls = v4l2_flash->ctrls;
+ bool is_strobing;
+ int ret;
+
+ switch (c->id) {
+ case V4L2_CID_FLASH_TORCH_INTENSITY:
+ /*
+ * Update torch brightness only if in TORCH_MODE.
+ * In other modes torch led is turned off, which
+ * would spuriously inform the user space that
+ * V4L2_CID_FLASH_TORCH_INTENSITY control setting
+ * has changed.
+ */
+ if (ctrls[LED_MODE]->val == V4L2_FLASH_LED_MODE_TORCH) {
+ ret = led_update_brightness(led_cdev);
+ if (ret < 0)
+ return ret;
+ c->val = v4l2_flash_led_brightness_to_intensity(
+ ctrls[TORCH_INTENSITY],
+ led_cdev->brightness);
+ }
+ return 0;
+ case V4L2_CID_FLASH_INDICATOR_INTENSITY:
+ ret = led_update_brightness(led_cdev);
+ if (ret < 0)
+ return ret;
+ c->val = v4l2_flash_led_brightness_to_intensity(
+ ctrls[INDICATOR_INTENSITY],
+ led_cdev->brightness);
+ return 0;
+ case V4L2_CID_FLASH_INTENSITY:
+ ret = led_update_flash_brightness(flash);
+ if (ret < 0)
+ return ret;
+ /* no conversion is needed */
+ c->val = flash->brightness.val;
+ return 0;
+ case V4L2_CID_FLASH_STROBE_STATUS:
+ ret = led_get_flash_strobe(flash, &is_strobing);
+ if (ret < 0)
+ return ret;
+ c->val = is_strobing;
+ return 0;
+ case V4L2_CID_FLASH_FAULT:
+ /* led faults map directly to V4L2 flash faults */
+ return led_get_flash_fault(flash, &c->val);
+ case V4L2_CID_FLASH_SYNC_STROBE:
+ c->val = flash->sync_strobe;
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int v4l2_flash_s_ctrl(struct v4l2_ctrl *c)
+{
+ struct v4l2_flash *v4l2_flash = v4l2_ctrl_to_v4l2_flash(c);
+ struct led_classdev_flash *flash = v4l2_flash->flash;
+ struct led_classdev *led_cdev = &flash->led_cdev;
+ struct v4l2_ctrl **ctrls = v4l2_flash->ctrls;
+ enum led_brightness brightness;
+ bool external_strobe;
+ int ret = 0;
+
+ switch (c->id) {
+ case V4L2_CID_FLASH_LED_MODE:
+ switch (c->val) {
+ case V4L2_FLASH_LED_MODE_NONE:
+ led_set_brightness(led_cdev, LED_OFF);
+ return led_set_flash_strobe(flash, false);
+ case V4L2_FLASH_LED_MODE_FLASH:
+ /* Turn the torch LED off */
+ led_set_brightness(led_cdev, LED_OFF);
+ external_strobe = (ctrls[STROBE_SOURCE]->val ==
+ V4L2_FLASH_STROBE_SOURCE_EXTERNAL);
+
+ if (has_flash_op(v4l2_flash, external_strobe_set))
+ ret = call_flash_op(v4l2_flash,
+ external_strobe_set, v4l2_flash,
+ external_strobe);
+ return ret;
+ case V4L2_FLASH_LED_MODE_TORCH:
+ /* Stop flash strobing */
+ ret = led_set_flash_strobe(flash, false);
+ if (ret < 0)
+ return ret;
+
+ brightness =
+ v4l2_flash_intensity_to_led_brightness(
+ ctrls[TORCH_INTENSITY],
+ ctrls[TORCH_INTENSITY]->val);
+ led_set_brightness(led_cdev, brightness);
+ return 0;
+ }
+ break;
+ case V4L2_CID_FLASH_STROBE_SOURCE:
+ external_strobe = (c->val == V4L2_FLASH_STROBE_SOURCE_EXTERNAL);
+
+ return call_flash_op(v4l2_flash, external_strobe_set,
+ v4l2_flash, external_strobe);
+ case V4L2_CID_FLASH_STROBE:
+ if (ctrls[LED_MODE]->val != V4L2_FLASH_LED_MODE_FLASH ||
+ ctrls[STROBE_SOURCE]->val !=
+ V4L2_FLASH_STROBE_SOURCE_SOFTWARE)
+ return -EINVAL;
+ return led_set_flash_strobe(flash, true);
+ case V4L2_CID_FLASH_STROBE_STOP:
+ if (ctrls[LED_MODE]->val != V4L2_FLASH_LED_MODE_FLASH ||
+ ctrls[STROBE_SOURCE]->val !=
+ V4L2_FLASH_STROBE_SOURCE_SOFTWARE)
+ return -EINVAL;
+ return led_set_flash_strobe(flash, false);
+ case V4L2_CID_FLASH_TIMEOUT:
+ /* no conversion is needed */
+ return led_set_flash_timeout(flash, c->val);
+ case V4L2_CID_FLASH_INTENSITY:
+ /* no conversion is needed */
+ return led_set_flash_brightness(flash, c->val);
+ case V4L2_CID_FLASH_INDICATOR_INTENSITY:
+ brightness = v4l2_flash_intensity_to_led_brightness(
+ ctrls[INDICATOR_INTENSITY],
+ c->val);
+ led_set_brightness(led_cdev, brightness);
+ return 0;
+ case V4L2_CID_FLASH_TORCH_INTENSITY:
+ /*
+ * If not in MODE_TORCH don't call led-class brightness_set
+ * op, as it would result in turning the torch led on.
+ * Instead the value is cached only and will be written
+ * to the device upon transition to MODE_TORCH.
+ */
+ if (ctrls[LED_MODE]->val == V4L2_FLASH_LED_MODE_TORCH) {
+ brightness =
+ v4l2_flash_intensity_to_led_brightness(
+ ctrls[TORCH_INTENSITY],
+ c->val);
+ led_set_brightness(led_cdev, brightness);
+ }
+ return 0;
+ case V4L2_CID_FLASH_SYNC_STROBE:
+ flash->sync_strobe = c->val;
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static const struct v4l2_ctrl_ops v4l2_flash_ctrl_ops = {
+ .g_volatile_ctrl = v4l2_flash_g_volatile_ctrl,
+ .s_ctrl = v4l2_flash_s_ctrl,
+};
+
+static void fill_ctrl_init_data(struct v4l2_flash *v4l2_flash,
+ struct v4l2_flash_ctrl_config *flash_cfg,
+ struct v4l2_flash_ctrl_data *ctrl_init_data)
+{
+ struct led_classdev_flash *flash = v4l2_flash->flash;
+ const struct led_flash_ops *flash_ops = flash->ops;
+ struct led_classdev *led_cdev = &flash->led_cdev;
+ struct v4l2_ctrl_config *ctrl_cfg;
+ u32 mask;
+ s64 max;
+
+ /* Init FLASH_LED_MODE ctrl data */
+ mask = 1 << V4L2_FLASH_LED_MODE_NONE |
+ 1 << V4L2_FLASH_LED_MODE_TORCH;
+ if (led_cdev->flags & LED_DEV_CAP_FLASH)
+ mask |= 1 << V4L2_FLASH_LED_MODE_FLASH;
+
+ ctrl_init_data[LED_MODE].supported = true;
+ ctrl_cfg = &ctrl_init_data[LED_MODE].config;
+ ctrl_cfg->id = V4L2_CID_FLASH_LED_MODE;
+ ctrl_cfg->max = V4L2_FLASH_LED_MODE_TORCH;
+ ctrl_cfg->menu_skip_mask = ~mask;
+ ctrl_cfg->def = V4L2_FLASH_LED_MODE_NONE;
+ ctrl_cfg->flags = 0;
+
+ /* Init TORCH_INTENSITY ctrl data */
+ ctrl_init_data[TORCH_INTENSITY].supported = true;
+ ctrl_init_data[TORCH_INTENSITY].config = flash_cfg->torch_intensity;
+ ctrl_cfg = &ctrl_init_data[TORCH_INTENSITY].config;
+ ctrl_cfg->id = V4L2_CID_FLASH_TORCH_INTENSITY;
+ ctrl_cfg->flags = V4L2_CTRL_FLAG_VOLATILE;
+
+ if (!(led_cdev->flags & LED_DEV_CAP_FLASH))
+ return;
+
+ /* Init FLASH_STROBE_SOURCE ctrl data */
+ mask = 1 << V4L2_FLASH_STROBE_SOURCE_SOFTWARE;
+ if (flash_cfg->has_external_strobe) {
+ mask |= 1 << V4L2_FLASH_STROBE_SOURCE_EXTERNAL;
+ max = V4L2_FLASH_STROBE_SOURCE_EXTERNAL;
+ } else {
+ max = V4L2_FLASH_STROBE_SOURCE_SOFTWARE;
+ }
+
+ ctrl_init_data[STROBE_SOURCE].supported = true;
+ ctrl_cfg = &ctrl_init_data[STROBE_SOURCE].config;
+ ctrl_cfg->id = V4L2_CID_FLASH_STROBE_SOURCE;
+ ctrl_cfg->max = max;
+ ctrl_cfg->menu_skip_mask = ~mask;
+ ctrl_cfg->def = V4L2_FLASH_STROBE_SOURCE_SOFTWARE;
+
+ /* Init FLASH_STROBE ctrl data */
+ ctrl_init_data[FLASH_STROBE].supported = true;
+ ctrl_cfg = &ctrl_init_data[FLASH_STROBE].config;
+ ctrl_cfg->id = V4L2_CID_FLASH_STROBE;
+
+ /* Init STROBE_STOP ctrl data */
+ ctrl_init_data[STROBE_STOP].supported = true;
+ ctrl_cfg = &ctrl_init_data[STROBE_STOP].config;
+ ctrl_cfg->id = V4L2_CID_FLASH_STROBE_STOP;
+
+ /* Init STROBE_STATUS ctrl data */
+ if (flash_ops->strobe_get) {
+ ctrl_init_data[STROBE_STATUS].supported = true;
+ ctrl_cfg = &ctrl_init_data[STROBE_STATUS].config;
+ ctrl_cfg->id = V4L2_CID_FLASH_STROBE_STATUS;
+ ctrl_cfg->flags = V4L2_CTRL_FLAG_VOLATILE |
+ V4L2_CTRL_FLAG_READ_ONLY;
+ }
+
+ /* Init FLASH_TIMEOUT ctrl data */
+ if (flash_ops->timeout_set) {
+ ctrl_init_data[FLASH_TIMEOUT].supported = true;
+ ctrl_init_data[FLASH_TIMEOUT].config = flash_cfg->flash_timeout;
+ ctrl_cfg = &ctrl_init_data[FLASH_TIMEOUT].config;
+ ctrl_cfg->id = V4L2_CID_FLASH_TIMEOUT;
+ ctrl_cfg->flags = V4L2_CTRL_FLAG_VOLATILE;
+ }
+
+ /* Init FLASH_INTENSITY ctrl data */
+ if (flash_ops->flash_brightness_set) {
+ ctrl_init_data[FLASH_INTENSITY].supported = true;
+ ctrl_init_data[FLASH_INTENSITY].config =
+ flash_cfg->flash_intensity;
+ ctrl_cfg = &ctrl_init_data[FLASH_INTENSITY].config;
+ ctrl_cfg->id = V4L2_CID_FLASH_INTENSITY;
+ ctrl_cfg->flags = V4L2_CTRL_FLAG_VOLATILE;
+ }
+
+ /* Init INDICATOR_INTENSITY ctrl data */
+ if (flash_cfg->has_indicator) {
+ ctrl_init_data[INDICATOR_INTENSITY].supported = true;
+ ctrl_init_data[INDICATOR_INTENSITY].config =
+ flash_cfg->indicator_intensity;
+ ctrl_cfg = &ctrl_init_data[INDICATOR_INTENSITY].config;
+ ctrl_cfg->id = V4L2_CID_FLASH_INDICATOR_INTENSITY;
+ ctrl_cfg->flags = V4L2_CTRL_FLAG_VOLATILE;
+ }
+
+ /* Init FLASH_FAULT ctrl data */
+ if (flash_cfg->flash_faults) {
+ ctrl_init_data[FLASH_FAULT].supported = true;
+ ctrl_cfg = &ctrl_init_data[FLASH_FAULT].config;
+ ctrl_cfg->id = V4L2_CID_FLASH_FAULT;
+ ctrl_cfg->max = flash_cfg->flash_faults;
+ ctrl_cfg->flags = V4L2_CTRL_FLAG_VOLATILE |
+ V4L2_CTRL_FLAG_READ_ONLY;
+ }
+
+ if (led_cdev->flags & LED_DEV_CAP_COMPOUND) {
+ ctrl_init_data[SYNC_STROBE].supported = true;
+ ctrl_cfg = &ctrl_init_data[SYNC_STROBE].config;
+ ctrl_cfg->id = V4L2_CID_FLASH_SYNC_STROBE;
+ ctrl_cfg->flags = V4L2_CTRL_FLAG_VOLATILE;
+ }
+}
+
+static int v4l2_flash_init_controls(struct v4l2_flash *v4l2_flash,
+ struct v4l2_flash_ctrl_config *flash_cfg)
+
+{
+ struct v4l2_flash_ctrl_data *ctrl_init_data;
+ struct v4l2_ctrl *ctrl;
+ struct v4l2_ctrl_config *ctrl_cfg;
+ int i, ret, num_ctrls = 0;
+
+ /* allocate memory dynamically so as not to exceed stack frame size */
+ ctrl_init_data = kcalloc(NUM_FLASH_CTRLS, sizeof(*ctrl_init_data),
+ GFP_KERNEL);
+ if (!ctrl_init_data)
+ return -ENOMEM;
+
+ memset(ctrl_init_data, 0, sizeof(*ctrl_init_data));
+
+ fill_ctrl_init_data(v4l2_flash, flash_cfg, ctrl_init_data);
+
+ for (i = 0; i < NUM_FLASH_CTRLS; ++i)
+ if (ctrl_init_data[i].supported)
+ ++num_ctrls;
+
+ v4l2_ctrl_handler_init(&v4l2_flash->hdl, num_ctrls);
+
+ for (i = 0; i < NUM_FLASH_CTRLS; ++i) {
+ ctrl_cfg = &ctrl_init_data[i].config;
+ if (!ctrl_init_data[i].supported)
+ continue;
+
+ if (ctrl_cfg->id == V4L2_CID_FLASH_LED_MODE ||
+ ctrl_cfg->id == V4L2_CID_FLASH_STROBE_SOURCE)
+ ctrl = v4l2_ctrl_new_std_menu(&v4l2_flash->hdl,
+ &v4l2_flash_ctrl_ops,
+ ctrl_cfg->id,
+ ctrl_cfg->max,
+ ctrl_cfg->menu_skip_mask,
+ ctrl_cfg->def);
+ else
+ ctrl = v4l2_ctrl_new_std(&v4l2_flash->hdl,
+ &v4l2_flash_ctrl_ops,
+ ctrl_cfg->id,
+ ctrl_cfg->min,
+ ctrl_cfg->max,
+ ctrl_cfg->step,
+ ctrl_cfg->def);
+
+ if (ctrl)
+ ctrl->flags |= ctrl_cfg->flags;
+
+ if (i <= STROBE_SOURCE)
+ v4l2_flash->ctrls[i] = ctrl;
+ }
+
+ kfree(ctrl_init_data);
+
+ if (v4l2_flash->hdl.error) {
+ ret = v4l2_flash->hdl.error;
+ goto error_free_handler;
+ }
+
+ v4l2_ctrl_handler_setup(&v4l2_flash->hdl);
+
+ v4l2_flash->sd.ctrl_handler = &v4l2_flash->hdl;
+
+ return 0;
+
+error_free_handler:
+ v4l2_ctrl_handler_free(&v4l2_flash->hdl);
+ return ret;
+}
+
+/*
+ * V4L2 subdev internal operations
+ */
+
+static int v4l2_flash_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
+{
+ struct v4l2_flash *v4l2_flash = v4l2_subdev_to_v4l2_flash(sd);
+ struct led_classdev_flash *flash = v4l2_flash->flash;
+ struct led_classdev *led_cdev = &flash->led_cdev;
+ int ret = 0;
+
+ mutex_lock(&led_cdev->led_access);
+
+ if (!v4l2_fh_is_singular(&fh->vfh)) {
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ led_sysfs_disable(led_cdev);
+
+unlock:
+ mutex_unlock(&led_cdev->led_access);
+ return ret;
+}
+
+static int v4l2_flash_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
+{
+ struct v4l2_flash *v4l2_flash = v4l2_subdev_to_v4l2_flash(sd);
+ struct led_classdev_flash *flash = v4l2_flash->flash;
+ struct led_classdev *led_cdev = &flash->led_cdev;
+ int ret = 0;
+
+ mutex_lock(&led_cdev->led_access);
+
+ if (has_flash_op(v4l2_flash, external_strobe_set))
+ ret = call_flash_op(v4l2_flash, external_strobe_set,
+ v4l2_flash, false);
+ led_sysfs_enable(led_cdev);
+
+ mutex_unlock(&led_cdev->led_access);
+
+ return ret;
+}
+
+static const struct v4l2_subdev_internal_ops v4l2_flash_subdev_internal_ops = {
+ .open = v4l2_flash_open,
+ .close = v4l2_flash_close,
+};
+
+static const struct v4l2_subdev_core_ops v4l2_flash_core_ops = {
+ .queryctrl = v4l2_subdev_queryctrl,
+ .querymenu = v4l2_subdev_querymenu,
+};
+
+static const struct v4l2_subdev_ops v4l2_flash_subdev_ops = {
+ .core = &v4l2_flash_core_ops,
+};
+
+struct v4l2_flash *v4l2_flash_init(struct led_classdev_flash *flash,
+ const struct v4l2_flash_ops *ops,
+ struct v4l2_flash_ctrl_config *config)
+{
+ struct v4l2_flash *v4l2_flash;
+ struct led_classdev *led_cdev = &flash->led_cdev;
+ struct v4l2_subdev *sd;
+ int ret;
+
+ if (!flash || !ops || !config)
+ return ERR_PTR(-EINVAL);
+
+ v4l2_flash = kzalloc(sizeof(*v4l2_flash), GFP_KERNEL);
+ if (!v4l2_flash)
+ return ERR_PTR(-ENOMEM);
+
+ sd = &v4l2_flash->sd;
+ v4l2_flash->flash = flash;
+ v4l2_flash->ops = ops;
+ sd->dev = led_cdev->dev->parent;
+ v4l2_subdev_init(sd, &v4l2_flash_subdev_ops);
+ sd->internal_ops = &v4l2_flash_subdev_internal_ops;
+ sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+ snprintf(sd->name, sizeof(sd->name), led_cdev->name);
+
+ ret = v4l2_flash_init_controls(v4l2_flash, config);
+ if (ret < 0)
+ goto err_init_controls;
+
+ ret = media_entity_init(&sd->entity, 0, NULL, 0);
+ if (ret < 0)
+ goto err_init_entity;
+
+ sd->entity.type = MEDIA_ENT_T_V4L2_SUBDEV_FLASH;
+
+ ret = v4l2_async_register_subdev(sd);
+ if (ret < 0)
+ goto err_init_entity;
+
+ return v4l2_flash;
+
+err_init_entity:
+ media_entity_cleanup(&sd->entity);
+err_init_controls:
+ v4l2_ctrl_handler_free(sd->ctrl_handler);
+ kfree(v4l2_flash);
+
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(v4l2_flash_init);
+
+void v4l2_flash_release(struct v4l2_flash *v4l2_flash)
+{
+ struct v4l2_subdev *sd = &v4l2_flash->sd;
+
+ if (!v4l2_flash)
+ return;
+
+ v4l2_async_unregister_subdev(sd);
+ media_entity_cleanup(&sd->entity);
+ v4l2_ctrl_handler_free(sd->ctrl_handler);
+ kfree(v4l2_flash);
+}
+EXPORT_SYMBOL_GPL(v4l2_flash_release);
+
+MODULE_AUTHOR("Jacek Anaszewski <j.anaszewski@samsung.com>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("V4L2 Flash sub-device helpers");
diff --git a/include/media/v4l2-flash.h b/include/media/v4l2-flash.h
new file mode 100644
index 0000000..1e18df5
--- /dev/null
+++ b/include/media/v4l2-flash.h
@@ -0,0 +1,138 @@
+/*
+ * V4L2 Flash LED sub-device registration 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 _V4L2_FLASH_H
+#define _V4L2_FLASH_H
+
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-dev.h>
+#include <media/v4l2-event.h>
+#include <media/v4l2-ioctl.h>
+
+struct led_classdev_flash;
+struct led_classdev;
+struct v4l2_flash;
+enum led_brightness;
+
+enum ctrl_init_data_id {
+ LED_MODE,
+ TORCH_INTENSITY,
+ STROBE_SOURCE,
+ FLASH_STROBE,
+ STROBE_STOP,
+ STROBE_STATUS,
+ FLASH_TIMEOUT,
+ FLASH_INTENSITY,
+ INDICATOR_INTENSITY,
+ FLASH_FAULT,
+ SYNC_STROBE,
+ NUM_FLASH_CTRLS,
+};
+
+/*
+ * struct v4l2_flash_ctrl_data - flash control initialization data -
+ * filled basing on the features declared
+ * by the LED Flash class driver
+ * @config: initialization data for a control
+ * @supported: indicates whether a control is supported
+ * by the LED Flash class driver
+ */
+struct v4l2_flash_ctrl_data {
+ struct v4l2_ctrl_config config;
+ bool supported;
+};
+
+struct v4l2_flash_ops {
+ /* setup strobing the flash by hardware pin state assertion */
+ int (*external_strobe_set)(struct v4l2_flash *v4l2_flash,
+ bool enable);
+};
+
+/**
+ * struct v4l2_flash_ctrl_config - V4L2 Flash controls initialization data
+ * @torch_intensity: V4L2_CID_FLASH_TORCH_INTENSITY constraints
+ * @flash_intensity: V4L2_CID_FLASH_INTENSITY constraints
+ * @indicator_intensity: V4L2_CID_FLASH_INDICATOR_INTENSITY constraints
+ * @flash_timeout: V4L2_CID_FLASH_TIMEOUT constraints
+ * @flash_fault: possible flash faults
+ * @has_external_strobe: external strobe capability
+ */
+struct v4l2_flash_ctrl_config {
+ struct v4l2_ctrl_config torch_intensity;
+ struct v4l2_ctrl_config flash_intensity;
+ struct v4l2_ctrl_config indicator_intensity;
+ struct v4l2_ctrl_config flash_timeout;
+ u32 flash_faults;
+ bool has_external_strobe:1;
+ bool has_indicator:1;
+};
+
+/**
+ * struct v4l2_flash - Flash sub-device context
+ * @flash: LED Flash Class device controlled by this sub-device
+ * @ops: V4L2 specific flash ops
+ * @sd: V4L2 sub-device
+ * @hdl: flash controls handler
+ * @ctrls: array of pointers to controls, whose values define
+ the sub-device state
+ */
+struct v4l2_flash {
+ struct led_classdev_flash *flash;
+ const struct v4l2_flash_ops *ops;
+
+ struct v4l2_subdev sd;
+ struct v4l2_ctrl_handler hdl;
+ struct v4l2_ctrl *ctrls[STROBE_SOURCE + 1];
+};
+
+static inline struct v4l2_flash *v4l2_subdev_to_v4l2_flash(
+ struct v4l2_subdev *sd)
+{
+ return container_of(sd, struct v4l2_flash, sd);
+}
+
+static inline struct v4l2_flash *v4l2_ctrl_to_v4l2_flash(struct v4l2_ctrl *c)
+{
+ return container_of(c->handler, struct v4l2_flash, hdl);
+}
+
+#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
+/**
+ * v4l2_flash_init - initialize V4L2 flash led sub-device
+ * @led_fdev: the LED Flash Class device to wrap
+ * @config: initialization data for V4L2 Flash controls
+ * @flash_ops: V4L2 Flash device ops
+ *
+ * Create V4L2 subdev wrapping given LED subsystem device.
+
+ * Returns: A valid pointer, or, when an error occurs, the return
+ * value is encoded using ERR_PTR(). Use IS_ERR() to check and
+ * PTR_ERR() to obtain the numeric return value.
+ */
+struct v4l2_flash *v4l2_flash_init(struct led_classdev_flash *led_fdev,
+ const struct v4l2_flash_ops *ops,
+ struct v4l2_flash_ctrl_config *config);
+
+/**
+ * v4l2_flash_release - release V4L2 Flash sub-device
+ * @flash: the V4L2 Flash device to release
+ *
+ * Release V4L2 flash led subdev.
+ */
+void v4l2_flash_release(struct v4l2_flash *v4l2_flash);
+
+#else
+#define v4l2_flash_init(led_cdev, ops, config) (NULL)
+#define v4l2_flash_release(v4l2_flash)
+#endif /* CONFIG_V4L2_FLASH_LED_CLASS */
+
+#endif /* _V4L2_FLASH_H */
--
1.7.9.5