Re: [PATCH v9 2/8] media: Add registration helpers for V4L2 flash sub-devices

[Alexey Klimov <klimov.linux-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

Hi Jacek,

On Mon, May 25, 2015 at 6:13 PM, Jacek Anaszewski
<j.anaszewski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org> wrote:
> 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-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
> Acked-by: Kyungmin Park <kyungmin.park-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
> Cc: Sakari Ailus <sakari.ailus-X3B1VOXEql0@public.gmane.org>
> Cc: Hans Verkuil <hans.verkuil-FYB4Gu1CFyUAvxtiuMwx3w@public.gmane.org>
> ---
>  drivers/media/v4l2-core/Kconfig                |   11 +
>  drivers/media/v4l2-core/Makefile               |    2 +
>  drivers/media/v4l2-core/v4l2-flash-led-class.c |  671 ++++++++++++++++++++++++
>  include/media/v4l2-flash-led-class.h           |  148 ++++++
>  4 files changed, 832 insertions(+)
>  create mode 100644 drivers/media/v4l2-core/v4l2-flash-led-class.c
>  create mode 100644 include/media/v4l2-flash-led-class.h
>
> diff --git a/drivers/media/v4l2-core/Kconfig b/drivers/media/v4l2-core/Kconfig
> index f7a01a7..b4b0229 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 "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
> diff --git a/drivers/media/v4l2-core/Makefile b/drivers/media/v4l2-core/Makefile
> index 63d29f2..dc3de00 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-$(CONFIG_V4L2_FLASH_LED_CLASS) += v4l2-flash-led-class.o
> +
>  obj-$(CONFIG_VIDEOBUF_GEN) += videobuf-core.o
>  obj-$(CONFIG_VIDEOBUF_DMA_SG) += videobuf-dma-sg.o
>  obj-$(CONFIG_VIDEOBUF_DMA_CONTIG) += videobuf-dma-contig.o
> diff --git a/drivers/media/v4l2-core/v4l2-flash-led-class.c b/drivers/media/v4l2-core/v4l2-flash-led-class.c
> new file mode 100644
> index 0000000..7599415c
> --- /dev/null
> +++ b/drivers/media/v4l2-core/v4l2-flash-led-class.c
> @@ -0,0 +1,671 @@
> +/*
> + * V4L2 flash LED sub-device registration helpers.
> + *
> + *     Copyright (C) 2015 Samsung Electronics Co., Ltd
> + *     Author: Jacek Anaszewski <j.anaszewski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
> + *
> + * 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]) {
> +               if (ctrls[LED_MODE]->val != V4L2_FLASH_LED_MODE_TORCH)
> +                       return;
> +
> +               led_set_brightness(&v4l2_flash->fled_cdev->led_cdev,
> +                                       brightness);
> +       } else {
> +               led_set_brightness(&v4l2_flash->iled_cdev->led_cdev,
> +                                       brightness);
> +       }
> +}
> +
> +static int v4l2_flash_update_led_brightness(struct v4l2_flash *v4l2_flash,
> +                                       struct v4l2_ctrl *ctrl)
> +{
> +       struct v4l2_ctrl **ctrls = v4l2_flash->ctrls;
> +       struct led_classdev *led_cdev;
> +       int ret;
> +
> +       if (ctrl == ctrls[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 value
> +                * has changed to 0.
> +                */
> +               if (ctrls[LED_MODE]->val != V4L2_FLASH_LED_MODE_TORCH)
> +                       return 0;
> +               led_cdev = &v4l2_flash->fled_cdev->led_cdev;
> +       } else {
> +               led_cdev = &v4l2_flash->iled_cdev->led_cdev;
> +       }
> +
> +       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 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->torch_intensity, ctrl_cfg);
> +       ctrl_cfg->id = V4L2_CID_FLASH_TORCH_INTENSITY;
> +       ctrl_cfg->flags = V4L2_CTRL_FLAG_VOLATILE |
> +                         V4L2_CTRL_FLAG_EXECUTE_ON_WRITE;
> +
> +       /* Init INDICATOR_INTENSITY ctrl data */
> +       if (v4l2_flash->iled_cdev) {
> +               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->indicator_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;
> +       }
> +
> +       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;
> +
> +       v4l2_flash_set_led_brightness(v4l2_flash, ctrls[TORCH_INTENSITY]);
> +
> +       if (ctrls[INDICATOR_INTENSITY])
> +               v4l2_flash_set_led_brightness(v4l2_flash,
> +                                               ctrls[INDICATOR_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 device *dev, struct device_node *of_node,
> +       struct led_classdev_flash *fled_cdev,
> +       struct led_classdev_flash *iled_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);

Could you please if it is correct? You're checking fled_cdev but four
lines above you're using fled_cdev and taking led_cdev pointer from
there. Maybe it's better to move calculation of led_cdev down and
place after if-check?

Best regards,
Alexey Klimov



-- 
Best regards, Klimov Alexey
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