[PATCH 3/7] drm/bridge: Extend struct drm_bus_cfg with clock field

[Marek Vasut <marex@xxxxxxx>]

Extend struct drm_bus_cfg with a clock field. This makes it possible for an
upstream bridge (further from scanout engine) to indicate to a downstream
bridge which frequency it expects on a link. This is particularly useful in
case of DSI bridges which derive their own internal clock from the DSI HS
clock.

Signed-off-by: Marek Vasut <marex@xxxxxxx>
Cc: Laurent Pinchart <Laurent.pinchart@xxxxxxxxxxxxxxxx>
Cc: Maxime Ripard <maxime@xxxxxxxxxx>
Cc: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
Cc: Sam Ravnborg <sam@xxxxxxxxxxxx>
---
 drivers/gpu/drm/drm_bridge.c | 6 ++++++
 include/drm/drm_atomic.h     | 5 +++++
 2 files changed, 11 insertions(+)

diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
index a069c50cc7d6b..6a5981b82499a 100644
--- a/drivers/gpu/drm/drm_bridge.c
+++ b/drivers/gpu/drm/drm_bridge.c
@@ -859,7 +859,9 @@ static int select_bus_fmt_recursive(struct drm_bridge *first_bridge,
 		 */
 		if (cur_state) {
 			cur_state->input_bus_cfg.format = MEDIA_BUS_FMT_FIXED;
+			cur_state->input_bus_cfg.clock = 0;
 			cur_state->output_bus_cfg.format = out_bus_cfg->format;
+			cur_state->output_bus_cfg.clock = out_bus_cfg->clock;
 		}
 
 		return 0;
@@ -911,7 +913,9 @@ static int select_bus_fmt_recursive(struct drm_bridge *first_bridge,
 
 	if (first_bridge == cur_bridge) {
 		cur_state->input_bus_cfg.format = in_bus_cfgs[0].format;
+		cur_state->input_bus_cfg.clock = in_bus_cfgs[0].clock;
 		cur_state->output_bus_cfg.format = out_bus_cfg->format;
+		cur_state->output_bus_cfg.clock = out_bus_cfg->clock;
 		kfree(in_bus_cfgs);
 		return 0;
 	}
@@ -926,7 +930,9 @@ static int select_bus_fmt_recursive(struct drm_bridge *first_bridge,
 
 	if (!ret) {
 		cur_state->input_bus_cfg.format = in_bus_cfgs[i].format;
+		cur_state->input_bus_cfg.clock = in_bus_cfgs[i].clock;
 		cur_state->output_bus_cfg.format = out_bus_cfg->format;
+		cur_state->output_bus_cfg.clock = out_bus_cfg->clock;
 	}
 
 	kfree(in_bus_cfgs);
diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
index 1701c2128a5cb..32455cf28f0bc 100644
--- a/include/drm/drm_atomic.h
+++ b/include/drm/drm_atomic.h
@@ -1077,6 +1077,11 @@ struct drm_bus_cfg {
 	 * @flags: DRM_BUS_* flags used on this bus
 	 */
 	u32 flags;
+
+	/**
+	 * @clock: Clock frequency in kHz used on this bus
+	 */
+	u32 clock;
 };
 
 /**
-- 
2.34.1