drm: crc: Introduce get_crc_sources callback

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@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/20180713135942.25061-3-mahesh1.kumar@intel.com

diff --git a/drivers/gpu/drm/drm_debugfs_crc.c b/drivers/gpu/drm/drm_debugfs_crc.c
index 72bfd8af3f7a2d0bb373da3ba3358d3eb1c7ba7d..d7e626331ecafb5ed85d7947fabe7e6042e909c8 100644 (file)
--- 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;
+
+               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 9dcbce93aeaea07bcff67bd4c949a23bddfac801..f2dd180a867abda8cafb463411d33ba249cf44c8 100644 (file)
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -762,6 +762,28 @@ 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
+        * 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
+        * source from the list.
+        */
+       const char *const *(*get_crc_sources)(struct drm_crtc *crtc,
+                                             size_t *count);
 
        /**
         * @atomic_print_state: