[PATCH v7 5/8] drm/bridge: sii902x: Support format negotiation hooks

[Aradhya Bhatia]

With new connector model, sii902x will not create the connector, when
DRM_BRIDGE_ATTACH_NO_CONNECTOR is set and SoC driver will rely on format
negotiation to setup the encoder format.

Support format negotiations hooks in the drm_bridge_funcs.
Use helper functions for state management.

Input format is selected to MEDIA_BUS_FMT_RGB888_1X24 as default, as is
the case with older model.

Signed-off-by: Aradhya Bhatia <a-bhatia1 at ti.com>
Reviewed-by: Neil Armstrong <neil.armstrong at linaro.org>
---

Notes:

    changes from v6:
    * Add Neil Armstrong's R-b tag.

 drivers/gpu/drm/bridge/sii902x.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/drivers/gpu/drm/bridge/sii902x.c b/drivers/gpu/drm/bridge/sii902x.c
index ef66461e7f7c..70aeb04b7f77 100644
--- a/drivers/gpu/drm/bridge/sii902x.c
+++ b/drivers/gpu/drm/bridge/sii902x.c
@@ -473,6 +473,27 @@ static struct edid *sii902x_bridge_get_edid(struct drm_bridge *bridge,
 	return sii902x_get_edid(sii902x, connector);
 }
 
+static u32 *sii902x_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
+						     struct drm_bridge_state *bridge_state,
+						     struct drm_crtc_state *crtc_state,
+						     struct drm_connector_state *conn_state,
+						     u32 output_fmt,
+						     unsigned int *num_input_fmts)
+{
+	u32 *input_fmts;
+
+	*num_input_fmts = 0;
+
+	input_fmts = kcalloc(1, sizeof(*input_fmts), GFP_KERNEL);
+	if (!input_fmts)
+		return NULL;
+
+	input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24;
+	*num_input_fmts = 1;
+
+	return input_fmts;
+}
+
 static const struct drm_bridge_funcs sii902x_bridge_funcs = {
 	.attach = sii902x_bridge_attach,
 	.mode_set = sii902x_bridge_mode_set,
@@ -480,6 +501,10 @@ static const struct drm_bridge_funcs sii902x_bridge_funcs = {
 	.enable = sii902x_bridge_enable,
 	.detect = sii902x_bridge_detect,
 	.get_edid = sii902x_bridge_get_edid,
+	.atomic_reset = drm_atomic_helper_bridge_reset,
+	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
+	.atomic_get_input_bus_fmts = sii902x_bridge_atomic_get_input_bus_fmts,
 };
 
 static int sii902x_mute(struct sii902x *sii902x, bool mute)
-- 
2.40.1