Hi Jacek, Thanks for the updated set. Some comments below. On Fri, Mar 20, 2015 at 04:03:27PM +0100, Jacek Anaszewski 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@xxxxxxxxxxx> > Acked-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx> > Cc: Sakari Ailus <sakari.ailus@xxxxxx> > Cc: Hans Verkuil <hans.verkuil@xxxxxxxxx> > --- > drivers/media/v4l2-core/Kconfig | 12 + > drivers/media/v4l2-core/Makefile | 2 + > drivers/media/v4l2-core/v4l2-flash.c | 607 ++++++++++++++++++++++++++++++++++ > include/media/v4l2-flash.h | 145 ++++++++ > 4 files changed, 766 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..0659598 100644 > --- a/drivers/media/v4l2-core/Kconfig > +++ b/drivers/media/v4l2-core/Kconfig > @@ -44,6 +44,18 @@ 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 > + depends on OF I think you can drop OF dependency. A no-op implementation will be used if it's disabled. > + ---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..804c2e4 > --- /dev/null > +++ b/drivers/media/v4l2-core/v4l2-flash.c > @@ -0,0 +1,607 @@ > +/* > + * V4L2 Flash LED sub-device registration helpers. > + * > + * Copyright (C) 2015 Samsung Electronics Co., Ltd > + * Author: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx> > + * > + * 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.h> > +#include "../../leds/leds.h" What do you need from leds.h? Shouldn't this be e.g. under include/linux instead? > +#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) > + > +static enum led_brightness __intensity_to_led_brightness( > + struct v4l2_ctrl *ctrl, > + s32 intensity) > +{ > + s64 intensity64 = intensity - ctrl->minimum; > + > + do_div(intensity64, 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->id != V4L2_CID_FLASH_INDICATOR_INTENSITY) > + ++intensity64; > + > + return intensity64; > +} > + > +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 */ > + 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 */ > + return led_set_flash_timeout(fled_cdev, c->val); > + case V4L2_CID_FLASH_INTENSITY: > + /* no conversion is needed */ > + 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 fill_ctrl_init_data(struct v4l2_flash *v4l2_flash, > + struct v4l2_flash_ctrl_config *flash_ctrl_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_ctrl_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_ctrl_cfg->flash_faults; > + ctrl_cfg->flags = V4L2_CTRL_FLAG_VOLATILE | > + V4L2_CTRL_FLAG_READ_ONLY; > + } > + > + /* Init INDICATOR_INTENSITY ctrl data */ > + if (flash_ctrl_cfg->indicator_led) { > + ctrl_init_data[INDICATOR_INTENSITY].cid = > + V4L2_CID_FLASH_INDICATOR_INTENSITY; > + ctrl_init_data[INDICATOR_INTENSITY].config = > + flash_ctrl_cfg->intensity; > + ctrl_cfg = &ctrl_init_data[INDICATOR_INTENSITY].config; > + ctrl_cfg->id = V4L2_CID_FLASH_INDICATOR_INTENSITY; > + ctrl_cfg->min = 0; > + ctrl_cfg->flags = V4L2_CTRL_FLAG_VOLATILE; > + > + /* 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_init_data[TORCH_INTENSITY].config = flash_ctrl_cfg->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 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_ctrl_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_init_data[FLASH_TIMEOUT].config = > + flash_ctrl_cfg->flash_timeout; > + ctrl_cfg = &ctrl_init_data[FLASH_TIMEOUT].config; > + 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_init_data[FLASH_INTENSITY].config = > + flash_ctrl_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; > + } > +} > + > +static int v4l2_flash_init_controls(struct v4l2_flash *v4l2_flash, > + struct v4l2_flash_ctrl_config *flash_ctrl_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; > + > + fill_ctrl_init_data(v4l2_flash, flash_ctrl_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[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); > + > + if (ctrls[INDICATOR_INTENSITY]) > + v4l2_flash_set_led_brightness(v4l2_flash, > + ctrls[INDICATOR_INTENSITY]); > + else > + v4l2_flash_set_led_brightness(v4l2_flash, > + ctrls[TORCH_INTENSITY]); > + > + 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; No need to initialise ret. > + > + mutex_lock(&led_cdev->led_access); > + > + if (!v4l2_fh_is_singular(&fh->vfh)) { I'm not sure about this --- no current flash driver AFAIK provides exclusive access. > + ret = -EBUSY; > + 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; ret is redundant. > + > + mutex_lock(&led_cdev->led_access); > + > + if (v4l2_flash->ctrls[STROBE_SOURCE]) > + 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_ctrl_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) You're missing media_entity_cleanup() here. How about adding a new label below for that? > + return ERR_PTR(ret); > + > + 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); > + 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 = &v4l2_flash->sd; > + struct led_classdev *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@xxxxxxxxxxx>"); > +MODULE_DESCRIPTION("V4L2 Flash sub-device helpers"); > +MODULE_LICENSE("GPL v2"); > diff --git a/include/media/v4l2-flash.h b/include/media/v4l2-flash.h > new file mode 100644 > index 0000000..cc0138d > --- /dev/null > +++ b/include/media/v4l2-flash.h > @@ -0,0 +1,145 @@ > +/* > + * V4L2 Flash LED sub-device registration helpers. > + * > + * Copyright (C) 2015 Samsung Electronics Co., Ltd > + * Author: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx> > + * > + * 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; > + > +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, > +}; > + > +/* > + * 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_ctrl_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_ctrl_config - V4L2 Flash controls initialization data This is a bit more than just about controls. How about dropping "_ctrl" from the name? > + * @dev_name: human readable device name Could you use "the name of the media entity, unique in the system" instead, please? > + * @intensity: constraints for the led in a non-flash mode > + * @flash_intensity: V4L2_CID_FLASH_INTENSITY constraints > + * @flash_timeout: V4L2_CID_FLASH_TIMEOUT constraints > + * @flash_faults: possible flash faults Please refer to documentation > + * @has_external_strobe: external strobe capability > + * @indicator_led: signifies that a led is of indicator type > + */ > +struct v4l2_flash_ctrl_config { > + char dev_name[32]; > + struct v4l2_ctrl_config intensity; > + struct v4l2_ctrl_config flash_intensity; > + struct v4l2_ctrl_config flash_timeout; I think I may have suggested using v4l2_ctrl_config here, but currently the drivers need to copy the values to v4l2_ctrl_config struct, instead of using struct led_flash_setting which they have to use anyway. What would you think it'd be feasible to use led_flash_setting here as well? > + 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[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 > + * @fled_cdev: the LED Flash class device to wrap > + * @flash_ops: V4L2 Flash device ops > + * @config: initialization data for V4L2 Flash controls > + * > + * 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_ctrl_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 */ -- Kind regards, Sakari Ailus e-mail: sakari.ailus@xxxxxx XMPP: sailus@xxxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html