@@ -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 "V4L2 flash API for LED flash class devices"
+ depends on VIDEO_V4L2_SUBDEV_API
+ depends on LEDS_CLASS_FLASH
+ ---help---
+ Say Y here to enable V4L2 flash API support for LED flash
+ class drivers.
+
+ When in doubt, say N.
+
# Used by drivers that need Videobuf modules
config VIDEOBUF_GEN
tristate
@@ -22,6 +22,8 @@ obj-$(CONFIG_VIDEO_TUNER) += tuner.o
obj-$(CONFIG_V4L2_MEM2MEM_DEV) += v4l2-mem2mem.o
+obj-$(CONFIG_V4L2_FLASH_LED_CLASS) += v4l2-flash-led-class.o
+
obj-$(CONFIG_VIDEOBUF_GEN) += videobuf-core.o
obj-$(CONFIG_VIDEOBUF_DMA_SG) += videobuf-dma-sg.o
obj-$(CONFIG_VIDEOBUF_DMA_CONTIG) += videobuf-dma-contig.o
new file mode 100644
@@ -0,0 +1,653 @@
+/*
+ * V4L2 flash LED sub-device registration helpers.
+ *
+ * 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/led-class-flash.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <media/v4l2-flash-led-class.h>
+
+#define has_flash_op(v4l2_flash, op) \
+ (v4l2_flash && v4l2_flash->ops->op)
+
+#define call_flash_op(v4l2_flash, op, arg) \
+ (has_flash_op(v4l2_flash, op) ? \
+ v4l2_flash->ops->op(v4l2_flash, arg) : \
+ -EINVAL)
+
+enum ctrl_init_data_id {
+ LED_MODE,
+ TORCH_INTENSITY,
+ FLASH_INTENSITY,
+ INDICATOR_INTENSITY,
+ FLASH_TIMEOUT,
+ STROBE_SOURCE,
+ /*
+ * Only above values are applicable to
+ * the 'ctrls' array in the struct v4l2_flash.
+ */
+ FLASH_STROBE,
+ STROBE_STOP,
+ STROBE_STATUS,
+ FLASH_FAULT,
+ NUM_FLASH_CTRLS,
+};
+
+static enum led_brightness __intensity_to_led_brightness(
+ struct v4l2_ctrl *ctrl, s32 intensity)
+{
+ intensity -= ctrl->minimum;
+ intensity /= (u32) ctrl->step;
+
+ /*
+ * Indicator LEDs, unlike torch LEDs, are turned on/off basing on
+ * the state of V4L2_CID_FLASH_INDICATOR_INTENSITY control only.
+ * Therefore it must be possible to set it to 0 level which in
+ * the LED subsystem reflects LED_OFF state.
+ */
+ if (ctrl->minimum)
+ ++intensity;
+
+ return intensity;
+}
+
+static s32 __led_brightness_to_intensity(struct v4l2_ctrl *ctrl,
+ enum led_brightness brightness)
+{
+ /*
+ * Indicator LEDs, unlike torch LEDs, are turned on/off basing on
+ * the state of V4L2_CID_FLASH_INDICATOR_INTENSITY control only.
+ * Do not decrement brightness read from the LED subsystem for
+ * indicator LED as it may equal 0. For torch LEDs this function
+ * is called only when V4L2_FLASH_LED_MODE_TORCH is set and the
+ * brightness read is guaranteed to be greater than 0. In the mode
+ * V4L2_FLASH_LED_MODE_NONE the cached torch intensity value is used.
+ */
+ if (ctrl->id != V4L2_CID_FLASH_INDICATOR_INTENSITY)
+ --brightness;
+
+ return (brightness * ctrl->step) + ctrl->minimum;
+}
+
+static void v4l2_flash_set_led_brightness(struct v4l2_flash *v4l2_flash,
+ struct v4l2_ctrl *ctrl)
+{
+ struct v4l2_ctrl **ctrls = v4l2_flash->ctrls;
+ enum led_brightness brightness;
+
+ if (has_flash_op(v4l2_flash, intensity_to_led_brightness))
+ brightness = call_flash_op(v4l2_flash,
+ intensity_to_led_brightness,
+ ctrl->val);
+ else
+ brightness = __intensity_to_led_brightness(ctrl, ctrl->val);
+ /*
+ * In case a LED Flash class driver provides ops for custom
+ * brightness <-> intensity conversion, it also must have defined
+ * related v4l2 control step == 1. In such a case a backward conversion
+ * from led brightness to v4l2 intensity is required to find out the
+ * the aligned intensity value.
+ */
+ if (has_flash_op(v4l2_flash, led_brightness_to_intensity))
+ ctrl->val = call_flash_op(v4l2_flash,
+ led_brightness_to_intensity,
+ brightness);
+
+ if (ctrl == ctrls[TORCH_INTENSITY] &&
+ ctrls[LED_MODE]->val != V4L2_FLASH_LED_MODE_TORCH)
+ return;
+
+ led_set_brightness(&v4l2_flash->fled_cdev->led_cdev, brightness);
+}
+
+static int v4l2_flash_update_led_brightness(struct v4l2_flash *v4l2_flash,
+ struct v4l2_ctrl *ctrl)
+{
+ struct led_classdev_flash *fled_cdev = v4l2_flash->fled_cdev;
+ struct led_classdev *led_cdev = &fled_cdev->led_cdev;
+ struct v4l2_ctrl **ctrls = v4l2_flash->ctrls;
+ int ret;
+
+ /*
+ * 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 value has changed to 0.
+ */
+ if (ctrl == ctrls[TORCH_INTENSITY] &&
+ ctrls[LED_MODE]->val != V4L2_FLASH_LED_MODE_TORCH)
+ return 0;
+
+ ret = led_update_brightness(led_cdev);
+ if (ret < 0)
+ return ret;
+
+ if (has_flash_op(v4l2_flash, led_brightness_to_intensity))
+ ctrl->val = call_flash_op(v4l2_flash,
+ led_brightness_to_intensity,
+ led_cdev->brightness);
+ else
+ ctrl->val = __led_brightness_to_intensity(ctrl,
+ led_cdev->brightness);
+
+ return 0;
+}
+
+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 *fled_cdev = v4l2_flash->fled_cdev;
+ bool is_strobing;
+ int ret;
+
+ switch (c->id) {
+ case V4L2_CID_FLASH_TORCH_INTENSITY:
+ case V4L2_CID_FLASH_INDICATOR_INTENSITY:
+ return v4l2_flash_update_led_brightness(v4l2_flash, c);
+ case V4L2_CID_FLASH_INTENSITY:
+ ret = led_update_flash_brightness(fled_cdev);
+ if (ret < 0)
+ return ret;
+ /*
+ * No conversion is needed as LED Flash class also uses
+ * microamperes for flash intensity units.
+ */
+ c->val = fled_cdev->brightness.val;
+ return 0;
+ case V4L2_CID_FLASH_STROBE_STATUS:
+ ret = led_get_flash_strobe(fled_cdev, &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(fled_cdev, &c->val);
+ default:
+ return -EINVAL;
+ }
+}
+
+static bool __software_strobe_mode_inactive(struct v4l2_ctrl **ctrls)
+{
+ return ((ctrls[LED_MODE]->val != V4L2_FLASH_LED_MODE_FLASH) ||
+ (ctrls[STROBE_SOURCE] && (ctrls[STROBE_SOURCE]->val !=
+ V4L2_FLASH_STROBE_SOURCE_SOFTWARE)));
+}
+
+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 *fled_cdev = v4l2_flash->fled_cdev;
+ struct led_classdev *led_cdev = &fled_cdev->led_cdev;
+ struct v4l2_ctrl **ctrls = v4l2_flash->ctrls;
+ 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(fled_cdev, false);
+ case V4L2_FLASH_LED_MODE_FLASH:
+ /* Turn the torch LED off */
+ led_set_brightness(led_cdev, LED_OFF);
+ if (ctrls[STROBE_SOURCE]) {
+ external_strobe = (ctrls[STROBE_SOURCE]->val ==
+ V4L2_FLASH_STROBE_SOURCE_EXTERNAL);
+
+ ret = call_flash_op(v4l2_flash,
+ external_strobe_set,
+ external_strobe);
+ }
+ return ret;
+ case V4L2_FLASH_LED_MODE_TORCH:
+ if (ctrls[STROBE_SOURCE]) {
+ ret = call_flash_op(v4l2_flash,
+ external_strobe_set,
+ false);
+ if (ret < 0)
+ return ret;
+ }
+ /* Stop flash strobing */
+ ret = led_set_flash_strobe(fled_cdev, false);
+ if (ret < 0)
+ return ret;
+
+ v4l2_flash_set_led_brightness(v4l2_flash,
+ ctrls[TORCH_INTENSITY]);
+ return 0;
+ }
+ break;
+ case V4L2_CID_FLASH_STROBE_SOURCE:
+ external_strobe = (c->val == V4L2_FLASH_STROBE_SOURCE_EXTERNAL);
+ /*
+ * For some hardware arrangements setting strobe source may
+ * affect torch mode. Therefore, if not in the flash mode,
+ * cache only this setting. It will be applied upon switching
+ * to flash mode.
+ */
+ if (ctrls[LED_MODE]->val != V4L2_FLASH_LED_MODE_FLASH)
+ return 0;
+
+ return call_flash_op(v4l2_flash, external_strobe_set,
+ external_strobe);
+ case V4L2_CID_FLASH_STROBE:
+ if (__software_strobe_mode_inactive(ctrls))
+ return -EBUSY;
+ return led_set_flash_strobe(fled_cdev, true);
+ case V4L2_CID_FLASH_STROBE_STOP:
+ if (__software_strobe_mode_inactive(ctrls))
+ return -EBUSY;
+ return led_set_flash_strobe(fled_cdev, false);
+ case V4L2_CID_FLASH_TIMEOUT:
+ /*
+ * No conversion is needed as LED Flash class also uses
+ * microseconds for flash timeout units.
+ */
+ return led_set_flash_timeout(fled_cdev, c->val);
+ case V4L2_CID_FLASH_INTENSITY:
+ /*
+ * No conversion is needed as LED Flash class also uses
+ * microamperes for flash intensity units.
+ */
+ return led_set_flash_brightness(fled_cdev, c->val);
+ case V4L2_CID_FLASH_TORCH_INTENSITY:
+ case V4L2_CID_FLASH_INDICATOR_INTENSITY:
+ v4l2_flash_set_led_brightness(v4l2_flash, c);
+ 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 __lfs_to_v4l2_ctrl_config(struct led_flash_setting *s,
+ struct v4l2_ctrl_config *c)
+{
+ c->min = s->min;
+ c->max = s->max;
+ c->step = s->step;
+ c->def = s->val;
+}
+
+static void __fill_ctrl_init_data(struct v4l2_flash *v4l2_flash,
+ struct v4l2_flash_config *flash_cfg,
+ struct v4l2_flash_ctrl_data *ctrl_init_data)
+{
+ struct led_classdev_flash *fled_cdev = v4l2_flash->fled_cdev;
+ const struct led_flash_ops *fled_cdev_ops = fled_cdev->ops;
+ struct led_classdev *led_cdev = &fled_cdev->led_cdev;
+ struct v4l2_ctrl_config *ctrl_cfg;
+ u32 mask;
+
+ /* Init FLASH_FAULT ctrl data */
+ if (flash_cfg->flash_faults) {
+ ctrl_init_data[FLASH_FAULT].cid = V4L2_CID_FLASH_FAULT;
+ 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;
+ }
+
+ /* Init INDICATOR_INTENSITY ctrl data */
+ if (flash_cfg->indicator_led) {
+ ctrl_init_data[INDICATOR_INTENSITY].cid =
+ V4L2_CID_FLASH_INDICATOR_INTENSITY;
+ ctrl_cfg = &ctrl_init_data[INDICATOR_INTENSITY].config;
+ __lfs_to_v4l2_ctrl_config(&flash_cfg->intensity, ctrl_cfg);
+ ctrl_cfg->id = V4L2_CID_FLASH_INDICATOR_INTENSITY;
+ ctrl_cfg->min = 0;
+ ctrl_cfg->flags = V4L2_CTRL_FLAG_VOLATILE |
+ V4L2_CTRL_FLAG_EXECUTE_ON_WRITE;
+
+ /* Indicator LED can have only faults and intensity controls. */
+ return;
+ }
+
+ /* 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].cid = V4L2_CID_FLASH_LED_MODE;
+ 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].cid = V4L2_CID_FLASH_TORCH_INTENSITY;
+ ctrl_cfg = &ctrl_init_data[TORCH_INTENSITY].config;
+ __lfs_to_v4l2_ctrl_config(&flash_cfg->intensity, ctrl_cfg);
+ ctrl_cfg->id = V4L2_CID_FLASH_TORCH_INTENSITY;
+ ctrl_cfg->flags = V4L2_CTRL_FLAG_VOLATILE |
+ V4L2_CTRL_FLAG_EXECUTE_ON_WRITE;
+
+ if (!(led_cdev->flags & LED_DEV_CAP_FLASH))
+ return;
+
+ /* Init FLASH_STROBE ctrl data */
+ ctrl_init_data[FLASH_STROBE].cid = V4L2_CID_FLASH_STROBE;
+ 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].cid = V4L2_CID_FLASH_STROBE_STOP;
+ ctrl_cfg = &ctrl_init_data[STROBE_STOP].config;
+ ctrl_cfg->id = V4L2_CID_FLASH_STROBE_STOP;
+
+ /* Init FLASH_STROBE_SOURCE ctrl data */
+ if (flash_cfg->has_external_strobe) {
+ mask = (1 << V4L2_FLASH_STROBE_SOURCE_SOFTWARE) |
+ (1 << V4L2_FLASH_STROBE_SOURCE_EXTERNAL);
+ ctrl_init_data[STROBE_SOURCE].cid =
+ V4L2_CID_FLASH_STROBE_SOURCE;
+ ctrl_cfg = &ctrl_init_data[STROBE_SOURCE].config;
+ ctrl_cfg->id = V4L2_CID_FLASH_STROBE_SOURCE;
+ ctrl_cfg->max = V4L2_FLASH_STROBE_SOURCE_EXTERNAL;
+ ctrl_cfg->menu_skip_mask = ~mask;
+ ctrl_cfg->def = V4L2_FLASH_STROBE_SOURCE_SOFTWARE;
+ }
+
+ /* Init STROBE_STATUS ctrl data */
+ if (fled_cdev_ops->strobe_get) {
+ ctrl_init_data[STROBE_STATUS].cid =
+ V4L2_CID_FLASH_STROBE_STATUS;
+ 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 (fled_cdev_ops->timeout_set) {
+ ctrl_init_data[FLASH_TIMEOUT].cid = V4L2_CID_FLASH_TIMEOUT;
+ ctrl_cfg = &ctrl_init_data[FLASH_TIMEOUT].config;
+ __lfs_to_v4l2_ctrl_config(&fled_cdev->timeout, ctrl_cfg);
+ ctrl_cfg->id = V4L2_CID_FLASH_TIMEOUT;
+ }
+
+ /* Init FLASH_INTENSITY ctrl data */
+ if (fled_cdev_ops->flash_brightness_set) {
+ ctrl_init_data[FLASH_INTENSITY].cid = V4L2_CID_FLASH_INTENSITY;
+ ctrl_cfg = &ctrl_init_data[FLASH_INTENSITY].config;
+ __lfs_to_v4l2_ctrl_config(&fled_cdev->brightness, ctrl_cfg);
+ ctrl_cfg->id = V4L2_CID_FLASH_INTENSITY;
+ ctrl_cfg->flags = V4L2_CTRL_FLAG_VOLATILE |
+ V4L2_CTRL_FLAG_EXECUTE_ON_WRITE;
+ }
+}
+
+static int v4l2_flash_init_controls(struct v4l2_flash *v4l2_flash,
+ struct v4l2_flash_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;
+
+ v4l2_flash->ctrls = devm_kzalloc(v4l2_flash->sd.dev,
+ sizeof(*v4l2_flash->ctrls) *
+ (STROBE_SOURCE + 1), GFP_KERNEL);
+ if (!v4l2_flash->ctrls)
+ return -ENOMEM;
+
+ /* 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;
+
+ __fill_ctrl_init_data(v4l2_flash, flash_cfg, ctrl_init_data);
+
+ for (i = 0; i < NUM_FLASH_CTRLS; ++i)
+ if (ctrl_init_data[i].cid)
+ ++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].cid)
+ 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;
+}
+
+static int __sync_device_with_v4l2_controls(struct v4l2_flash *v4l2_flash)
+{
+ struct led_classdev_flash *fled_cdev = v4l2_flash->fled_cdev;
+ struct v4l2_ctrl **ctrls = v4l2_flash->ctrls;
+ int ret = 0;
+
+ if (ctrls[INDICATOR_INTENSITY]) {
+ v4l2_flash_set_led_brightness(v4l2_flash,
+ ctrls[INDICATOR_INTENSITY]);
+ return 0;
+ }
+
+ v4l2_flash_set_led_brightness(v4l2_flash, ctrls[TORCH_INTENSITY]);
+
+ if (ctrls[FLASH_TIMEOUT]) {
+ ret = led_set_flash_timeout(fled_cdev,
+ ctrls[FLASH_TIMEOUT]->val);
+ if (ret < 0)
+ return ret;
+ }
+
+ if (ctrls[FLASH_INTENSITY]) {
+ ret = led_set_flash_brightness(fled_cdev,
+ ctrls[FLASH_INTENSITY]->val);
+ if (ret < 0)
+ return ret;
+ }
+
+ /*
+ * For some hardware arrangements setting strobe source may affect
+ * torch mode. Synchronize strobe source setting only if not in torch
+ * mode. For torch mode case it will get synchronized upon switching
+ * to flash mode.
+ */
+ if (ctrls[STROBE_SOURCE] &&
+ ctrls[LED_MODE]->val != V4L2_FLASH_LED_MODE_TORCH)
+ ret = call_flash_op(v4l2_flash, external_strobe_set,
+ ctrls[STROBE_SOURCE]->val);
+
+ 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 *fled_cdev = v4l2_flash->fled_cdev;
+ struct led_classdev *led_cdev = &fled_cdev->led_cdev;
+ int ret = 0;
+
+ mutex_lock(&led_cdev->led_access);
+
+ if (!v4l2_fh_is_singular(&fh->vfh))
+ goto unlock;
+
+ led_sysfs_disable(led_cdev);
+ led_trigger_remove(led_cdev);
+
+ ret = __sync_device_with_v4l2_controls(v4l2_flash);
+
+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 *fled_cdev = v4l2_flash->fled_cdev;
+ struct led_classdev *led_cdev = &fled_cdev->led_cdev;
+ int ret = 0;
+
+ mutex_lock(&led_cdev->led_access);
+
+ if (v4l2_fh_is_singular(&fh->vfh)) {
+ if (v4l2_flash->ctrls[STROBE_SOURCE])
+ ret = v4l2_ctrl_s_ctrl(v4l2_flash->ctrls[STROBE_SOURCE],
+ V4L2_FLASH_STROBE_SOURCE_SOFTWARE);
+ 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 *fled_cdev,
+ const struct v4l2_flash_ops *ops,
+ struct v4l2_flash_config *config)
+{
+ struct v4l2_flash *v4l2_flash;
+ struct led_classdev *led_cdev = &fled_cdev->led_cdev;
+ struct v4l2_subdev *sd;
+ int ret;
+
+ if (!fled_cdev || !ops || !config)
+ return ERR_PTR(-EINVAL);
+
+ v4l2_flash = devm_kzalloc(led_cdev->dev, sizeof(*v4l2_flash),
+ GFP_KERNEL);
+ if (!v4l2_flash)
+ return ERR_PTR(-ENOMEM);
+
+ sd = &v4l2_flash->sd;
+ v4l2_flash->fled_cdev = fled_cdev;
+ v4l2_flash->ops = ops;
+ sd->dev = led_cdev->dev;
+ v4l2_subdev_init(sd, &v4l2_flash_subdev_ops);
+ sd->internal_ops = &v4l2_flash_subdev_internal_ops;
+ sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+ strlcpy(sd->name, config->dev_name, sizeof(sd->name));
+
+ ret = media_entity_init(&sd->entity, 0, NULL, 0);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ sd->entity.type = MEDIA_ENT_T_V4L2_SUBDEV_FLASH;
+
+ ret = v4l2_flash_init_controls(v4l2_flash, config);
+ if (ret < 0)
+ goto err_init_controls;
+
+ of_node_get(led_cdev->dev->of_node);
+
+ ret = v4l2_async_register_subdev(sd);
+ if (ret < 0)
+ goto err_async_register_sd;
+
+ return v4l2_flash;
+
+err_async_register_sd:
+ of_node_put(led_cdev->dev->of_node);
+ v4l2_ctrl_handler_free(sd->ctrl_handler);
+err_init_controls:
+ media_entity_cleanup(&sd->entity);
+
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(v4l2_flash_init);
+
+void v4l2_flash_release(struct v4l2_flash *v4l2_flash)
+{
+ struct v4l2_subdev *sd;
+ struct led_classdev *led_cdev;
+
+ if (IS_ERR(v4l2_flash))
+ return;
+
+ sd = &v4l2_flash->sd;
+ led_cdev = &v4l2_flash->fled_cdev->led_cdev;
+
+ v4l2_async_unregister_subdev(sd);
+ of_node_put(led_cdev->dev->of_node);
+ v4l2_ctrl_handler_free(sd->ctrl_handler);
+ media_entity_cleanup(&sd->entity);
+}
+EXPORT_SYMBOL_GPL(v4l2_flash_release);
+
+MODULE_AUTHOR("Jacek Anaszewski <j.anaszewski@samsung.com>");
+MODULE_DESCRIPTION("V4L2 Flash sub-device helpers");
+MODULE_LICENSE("GPL v2");
new file mode 100644
@@ -0,0 +1,127 @@
+/*
+ * V4L2 flash LED sub-device registration helpers.
+ *
+ * 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.
+ */
+
+#ifndef _V4L2_FLASH_H
+#define _V4L2_FLASH_H
+
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-subdev.h>
+
+struct led_classdev_flash;
+struct led_classdev;
+struct v4l2_flash;
+enum led_brightness;
+
+/*
+ * struct v4l2_flash_ctrl_data - flash control initialization data, filled
+ * basing on the features declared by the LED Flash
+ * class driver in the v4l2_flash_config
+ * @config: initialization data for a control
+ * @cid: contains v4l2 flash control id if the config
+ * field was initialized, 0 otherwise
+ */
+struct v4l2_flash_ctrl_data {
+ struct v4l2_ctrl_config config;
+ u32 cid;
+};
+
+struct v4l2_flash_ops {
+ /* setup strobing the flash by hardware pin state assertion */
+ int (*external_strobe_set)(struct v4l2_flash *v4l2_flash,
+ bool enable);
+ /* convert intensity to brightness in a device specific manner */
+ enum led_brightness (*intensity_to_led_brightness)
+ (struct v4l2_flash *v4l2_flash, s32 intensity);
+ /* convert brightness to intensity in a device specific manner */
+ s32 (*led_brightness_to_intensity)
+ (struct v4l2_flash *v4l2_flash, enum led_brightness);
+};
+
+/**
+ * struct v4l2_flash_config - V4L2 Flash sub-device initialization data
+ * @dev_name: the name of the media entity,
+ unique in the system
+ * @intensity: constraints for the LED in a non-flash mode
+ * @flash_faults: bitmask of flash faults that the LED Flash class
+ device can report; corresponding LED_FAULT* bit
+ definitions are available in the header file
+ <linux/led-class-flash.h>
+ * @has_external_strobe: external strobe capability
+ * @indicator_led: signifies that a led is of indicator type
+ */
+struct v4l2_flash_config {
+ char dev_name[32];
+ struct led_flash_setting intensity;
+ u32 flash_faults;
+ unsigned int has_external_strobe:1;
+ unsigned int indicator_led:1;
+};
+
+/**
+ * struct v4l2_flash - Flash sub-device context
+ * @fled_cdev: 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 *fled_cdev;
+ const struct v4l2_flash_ops *ops;
+
+ struct v4l2_subdev sd;
+ struct v4l2_ctrl_handler hdl;
+ struct v4l2_ctrl **ctrls;
+};
+
+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
+ * @fled_cdev: the LED Flash class device to wrap
+ * @flash_ops: V4L2 Flash device ops
+ * @config: initialization data for V4L2 Flash sub-device
+ *
+ * Create V4L2 Flash sub-device 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 *fled_cdev,
+ const struct v4l2_flash_ops *ops,
+ struct v4l2_flash_config *config);
+
+/**
+ * v4l2_flash_release - release V4L2 Flash sub-device
+ * @flash: the V4L2 Flash sub-device to release
+ *
+ * Release V4L2 Flash sub-device.
+ */
+void v4l2_flash_release(struct v4l2_flash *v4l2_flash);
+
+#else
+#define v4l2_flash_init(fled_cdev, ops, config) (NULL)
+#define v4l2_flash_release(v4l2_flash)
+#endif /* CONFIG_V4L2_FLASH_LED_CLASS */
+
+#endif /* _V4L2_FLASH_H */