linux/include/media/v4l2-flash-led-class.h
Sakari Ailus 503dd28af1 media: v4l2-flash-led-class: Create separate sub-devices for indicators
The V4L2 flash interface allows controlling multiple LEDs through a single
sub-devices if, and only if, these LEDs are of different types. This
approach scales badly for flash controllers that drive multiple flash LEDs
or for LED specific associations. Essentially, the original assumption of a
LED driver chip that drives a single flash LED and an indicator LED is no
longer valid.

Address the matter by registering one sub-device per LED.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Rui Miguel Silva <rmfrfs@gmail.com> (for greybus/light)
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-08-26 20:26:35 -04:00

172 lines
5.3 KiB
C

/*
* 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 - V4L2 flash operations
*
* @external_strobe_set: Setup strobing the flash by hardware pin state
* assertion.
* @intensity_to_led_brightness: Convert intensity to brightness in a device
* specific manner
* @led_brightness_to_intensity: convert brightness to intensity in a device
* specific manner.
*/
struct v4l2_flash_ops {
int (*external_strobe_set)(struct v4l2_flash *v4l2_flash,
bool enable);
enum led_brightness (*intensity_to_led_brightness)
(struct v4l2_flash *v4l2_flash, s32 intensity);
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: non-flash strobe constraints for the LED
* @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
*/
struct v4l2_flash_config {
char dev_name[32];
struct led_flash_setting intensity;
u32 flash_faults;
unsigned int has_external_strobe:1;
};
/**
* struct v4l2_flash - Flash sub-device context
* @fled_cdev: LED flash class device controlled by this sub-device
* @iled_cdev: LED class device representing indicator LED associated
* with the LED flash class 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;
struct led_classdev *iled_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
* @dev: flash device, e.g. an I2C device
* @fwn: fwnode_handle of the LED, may be NULL if the same as device's
* @fled_cdev: LED flash class device to wrap
* @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 device *dev, struct fwnode_handle *fwn,
struct led_classdev_flash *fled_cdev,
const struct v4l2_flash_ops *ops, struct v4l2_flash_config *config);
/**
* v4l2_flash_indicator_init - initialize V4L2 indicator sub-device
* @dev: flash device, e.g. an I2C device
* @fwn: fwnode_handle of the LED, may be NULL if the same as device's
* @iled_cdev: LED flash class device representing the indicator LED
* @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_indicator_init(
struct device *dev, struct fwnode_handle *fwn,
struct led_classdev *iled_cdev, struct v4l2_flash_config *config);
/**
* v4l2_flash_release - release V4L2 Flash sub-device
* @v4l2_flash: the V4L2 Flash sub-device to release
*
* Release V4L2 Flash sub-device.
*/
void v4l2_flash_release(struct v4l2_flash *v4l2_flash);
#else
static inline struct v4l2_flash *v4l2_flash_init(
struct device *dev, struct fwnode_handle *fwn,
struct led_classdev_flash *fled_cdev,
const struct v4l2_flash_ops *ops, struct v4l2_flash_config *config)
{
return NULL;
}
static inline struct v4l2_flash *v4l2_flash_indicator_init(
struct device *dev, struct fwnode_handle *fwn,
struct led_classdev *iled_cdev, struct v4l2_flash_config *config)
{
return NULL;
}
static inline void v4l2_flash_release(struct v4l2_flash *v4l2_flash)
{
}
#endif /* CONFIG_V4L2_FLASH_LED_CLASS */
#endif /* _V4L2_FLASH_H */