drm: crc: Introduce verify_crc_source callback

This patch adds a new callback function "verify_crc_source" which will
be used during setting the crc source in control node. This will help
in avoiding setting of wrong string for source.

Changes since V1:
 - do not yet verify_crc_source during open.
Changes since V1:
 - improve callback description

Signed-off-by: Mahesh Kumar <mahesh1.kumar@intel.com>
Cc: dri-devel@lists.freedesktop.org
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180713135942.25061-2-mahesh1.kumar@intel.com

1 files changed, 16 insertions, 0 deletions

diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 92e7fc7f05a4..9dcbce93aeae 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -746,6 +746,22 @@ struct drm_crtc_funcs {
          */
         int (*set_crc_source)(struct drm_crtc *crtc, const char *source,
                               size_t *values_cnt);
+        /**
+         * @verify_crc_source:
+         *
+         * verifies the source of CRC checksums of frames before setting the
+         * source for CRC and during crc open. Source parameter can be NULL
+         * while disabling crc source.
+         *
+         * This callback is optional if the driver does not support any CRC
+         * generation functionality.
+         *
+         * RETURNS:
+         *
+         * 0 on success or a negative error code on failure.
+         */
+        int (*verify_crc_source)(struct drm_crtc *crtc, const char *source,
+                                 size_t *values_cnt);
 
         /**
          * @atomic_print_state: