[PATCH 18/28] drm/i915/writeback: Add connector atomic check

[Suraj Kandpal]

Add connector helper function for atomic check which sets the
mode_changed bit and checks if pixel format of fb is valid or not.

Signed-off-by: Suraj Kandpal <suraj.kand...@intel.com>
---
 .../gpu/drm/i915/display/intel_writeback.c    | 49 +++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_writeback.c 
b/drivers/gpu/drm/i915/display/intel_writeback.c
index 9b2432d86d35..7fb30cc61991 100644
--- a/drivers/gpu/drm/i915/display/intel_writeback.c
+++ b/drivers/gpu/drm/i915/display/intel_writeback.c
@@ -186,6 +186,54 @@ static void intel_writeback_connector_destroy(struct 
drm_connector *connector)
        kfree(connector);
 }
 
+static int intel_writeback_check_format(u32 format)
+{
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(writeback_formats); i++) {
+               if (writeback_formats[i] == format)
+                       return 0;
+       }
+
+       return -EINVAL;
+}
+
+static int intel_writeback_atomic_check(struct drm_connector *connector,
+                                       struct drm_atomic_state *state)
+{
+       struct drm_connector_state *conn_state =
+               drm_atomic_get_new_connector_state(state, connector);
+       struct drm_crtc_state *crtc_state;
+       struct drm_framebuffer *fb;
+       int ret;
+
+       /* We return 0 since this is called while disabling writeback encoder */
+       if (!conn_state->crtc)
+               return 0;
+
+       /* We do not allow a blank commit when using writeback connector */
+       if (!conn_state->writeback_job)
+               return -EINVAL;
+
+       fb = conn_state->writeback_job->fb;
+       if (!fb)
+               return -EINVAL;
+
+       crtc_state = drm_atomic_get_new_crtc_state(state, conn_state->crtc);
+       if (fb->width != crtc_state->mode.hdisplay ||
+           fb->height != crtc_state->mode.vdisplay)
+               return -EINVAL;
+
+       ret = intel_writeback_check_format(fb->format->format);
+       if (ret) {
+               drm_dbg_kms(connector->dev,
+                           "Unsupported drm format sent in writeback job\n");
+               return ret;
+       }
+
+       return 0;
+}
+
 static struct drm_writeback_connector *
 intel_get_writeback_connector(struct drm_connector *connector)
 {
@@ -221,6 +269,7 @@ static const struct drm_connector_helper_funcs 
conn_helper_funcs = {
        .get_writeback_connector = intel_get_writeback_connector,
        .get_modes = intel_writeback_get_modes,
        .mode_valid = intel_writeback_mode_valid,
+       .atomic_check = intel_writeback_atomic_check,
        .prepare_writeback_job = intel_writeback_prepare_job,
        .cleanup_writeback_job = intel_writeback_cleanup_job,
 };
-- 
2.34.1