[PATCH 02/10] drm: crc: Introduce get_crc_sources callback

[Laurent Pinchart]

Hi Mahesh,

Thank you for the patch.

On Thursday, 12 July 2018 11:36:27 EEST Mahesh Kumar wrote:
> This patch introduce a callback function "get_crc_sources" which
> will be called during read of control node. It is an optional
> callback function and if driver implements this callback, driver
> should return a constant pointer to an array of crc sources list
> and update count according to the number of source in the list.
> 
> Changes Since V1: (Daniel)
>  - return const pointer to an array of crc sources list
>  - do validation of sources in CRC-core
> Changes Since V2:
>  - update commit message
>  - update callback documentation
>  - print one source name per line
> 
> Signed-off-by: Mahesh Kumar <mahesh1.kumar at intel.com>
> Cc: dri-devel at lists.freedesktop.org
> Cc: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> Reviewed-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> ---
>  drivers/gpu/drm/drm_debugfs_crc.c | 23 ++++++++++++++++++++++-
>  include/drm/drm_crtc.h            | 22 ++++++++++++++++++++++
>  2 files changed, 44 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/drm_debugfs_crc.c
> b/drivers/gpu/drm/drm_debugfs_crc.c index 1956acb61cc8..940b76a1ab71 100644
> --- a/drivers/gpu/drm/drm_debugfs_crc.c
> +++ b/drivers/gpu/drm/drm_debugfs_crc.c
> @@ -68,8 +68,29 @@ static int crc_control_show(struct seq_file *m, void
> *data) {
>  	struct drm_crtc *crtc = m->private;
> 
> -	seq_printf(m, "%s\n", crtc->crc.source);
> +	if (crtc->funcs->get_crc_sources) {
> +		size_t count;
> +		const char *const *sources = crtc->funcs->get_crc_sources(crtc,
> +									&count);
> +		size_t values_cnt;
> +		int i;

i only takes positive values, you can make it an unsigned int.

> +		if (count == 0 || !sources)
> +			goto out;
> +
> +		for (i = 0; i < count; i++)
> +			if (!crtc->funcs->verify_crc_source(crtc, sources[i],
> +							    &values_cnt)) {
> +				if (strcmp(sources[i], crtc->crc.source))
> +					seq_printf(m, "%s\n", sources[i]);
> +				else
> +					seq_printf(m, "%s*\n", sources[i]);
> +			}
> +	}
> +	return 0;
> 
> +out:
> +	seq_printf(m, "%s*\n", crtc->crc.source);
>  	return 0;
>  }
> 
> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
> index 3ce5d2fe133d..69886025e628 100644
> --- a/include/drm/drm_crtc.h
> +++ b/include/drm/drm_crtc.h
> @@ -699,6 +699,28 @@ struct drm_crtc_funcs {
>  	 */
>  	int (*verify_crc_source)(struct drm_crtc *crtc, const char *source,
>  				 size_t *values_cnt);
> +	/**
> +	 * @get_crc_sources:
> +	 *
> +	 * Driver callback for getting a list of all the available sources for
> +	 * CRC generation. This callback depends upon verify_crc_source, So

s/So/so/

> +	 * verify_crc_source callback should be implemented before implementing
> +	 * this. Driver can pass full list of available crc sources, this
> +	 * callback does the verification on each crc-source before passing it
> +	 * to userspace.
> +	 *
> +	 * This callback is optional if the driver does not support exporting of
> +	 * possible CRC sources list.
> +	 *
> +	 * RETURNS:
> +	 *
> +	 * a constant character pointer to the list of all the available CRC
> +	 * sources. On failure driver should return NULL. count should be
> +	 * updated with number of sources in list. if zero we don't process any

s/if zero/If zero/

Apart from that,

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

> +	 * source from the list.
> +	 */
> +	const char *const *(*get_crc_sources)(struct drm_crtc *crtc,
> +					      size_t *count);
> 
>  	/**
>  	 * @atomic_print_state:

-- 
Regards,

Laurent Pinchart