Re: [PATCH RFC 1/2] [media] v4l2: add V4L2_INPUT_TYPE_DEFAULT

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Helen,

Thank you for the patch.

On Thursday 30 Mar 2017 13:02:17 Helen Koike wrote:
> Add V4L2_INPUT_TYPE_DEFAULT and helpers functions for input ioctls to be
> used when no inputs are available in the device
> 
> Signed-off-by: Helen Koike <helen.koike@collabora.com>
> ---
>  drivers/media/v4l2-core/v4l2-ioctl.c | 27 +++++++++++++++++++++++++++
>  include/media/v4l2-ioctl.h           | 26 ++++++++++++++++++++++++++
>  include/uapi/linux/videodev2.h       |  1 +
>  3 files changed, 54 insertions(+)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c
> b/drivers/media/v4l2-core/v4l2-ioctl.c index 0c3f238..ccaf04b 100644
> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> @@ -2573,6 +2573,33 @@ struct mutex *v4l2_ioctl_get_lock(struct video_device
> *vdev, unsigned cmd) return vdev->lock;
>  }
> 
> +int v4l2_ioctl_enum_input_default(struct file *file, void *priv,
> +				  struct v4l2_input *i)
> +{
> +	if (i->index > 0)
> +		return -EINVAL;
> +
> +	memset(i, 0, sizeof(*i));
> +	i->type = V4L2_INPUT_TYPE_DEFAULT;
> +	strlcpy(i->name, "Default", sizeof(i->name));
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(v4l2_ioctl_enum_input_default);

V4L2 tends to use EXPORT_SYMBOL_GPL.

What would you think about calling those default functions directly from the 
core when the input ioctl handlers are not set ? You wouldn't need to modify 
drivers.

> +
> +int v4l2_ioctl_g_input_default(struct file *file, void *priv, unsigned int
> *i) +{
> +	*i = 0;
> +	return 0;
> +}
> +EXPORT_SYMBOL(v4l2_ioctl_g_input_default);
> +
> +int v4l2_ioctl_s_input_default(struct file *file, void *priv, unsigned int
> i) +{
> +	return i ? -EINVAL : 0;
> +}
> +EXPORT_SYMBOL(v4l2_ioctl_s_input_default);
> +
>  /* Common ioctl debug function. This function can be used by
>     external ioctl messages as well as internal V4L ioctl */
>  void v4l_printk_ioctl(const char *prefix, unsigned int cmd)
> diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h
> index 6cd94e5..accc470 100644
> --- a/include/media/v4l2-ioctl.h
> +++ b/include/media/v4l2-ioctl.h
> @@ -652,6 +652,32 @@ struct video_device;
>   */
>  struct mutex *v4l2_ioctl_get_lock(struct video_device *vdev, unsigned int
> cmd);
> 
> +
> +/**
> + * v4l2_ioctl_enum_input_default - v4l2 ioctl helper for VIDIOC_ENUM_INPUT
> ioctl + *
> + * Plug this function in vidioc_enum_input field of the struct
> v4l2_ioctl_ops to + * enumerate a single input as V4L2_INPUT_TYPE_DEFAULT
> + */
> +int v4l2_ioctl_enum_input_default(struct file *file, void *priv,
> +				  struct v4l2_input *i);
> +
> +/**
> + * v4l2_ioctl_g_input_default - v4l2 ioctl helper for VIDIOC_G_INPUT ioctl
> + *
> + * Plug this function in vidioc_g_input field of the struct v4l2_ioctl_ops
> + * when using v4l2_ioctl_enum_input_default
> + */
> +int v4l2_ioctl_g_input_default(struct file *file, void *priv, unsigned int
> *i); +
> +/**
> + * v4l2_ioctl_s_input_default - v4l2 ioctl helper for VIDIOC_S_INPUT ioctl
> + *
> + * Plug this function in vidioc_s_input field of the struct v4l2_ioctl_ops
> + * when using v4l2_ioctl_enum_input_default
> + */
> +int v4l2_ioctl_s_input_default(struct file *file, void *priv, unsigned int
> i); +
>  /* names for fancy debug output */
>  extern const char *v4l2_field_names[];
>  extern const char *v4l2_type_names[];
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 316be62..c10bbde 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -1477,6 +1477,7 @@ struct v4l2_input {
>  };
> 
>  /*  Values for the 'type' field */
> +#define V4L2_INPUT_TYPE_DEFAULT		0
>  #define V4L2_INPUT_TYPE_TUNER		1
>  #define V4L2_INPUT_TYPE_CAMERA		2
>  #define V4L2_INPUT_TYPE_TOUCH		3

-- 
Regards,

Laurent Pinchart