From 5044e5f2511c9afdf9880d2bb6b9d37dfc345dac Mon Sep 17 00:00:00 2001 From: Dave Stevenson Date: Mon, 5 Dec 2022 17:33:26 +0000 Subject: drm/bridge: Introduce pre_enable_prev_first to alter bridge init order [ Upstream commit 4fb912e5e19075874379cfcf074d90bd51ebf8ea ] DSI sink devices typically want the DSI host powered up and configured before they are powered up. pre_enable is the place this would normally happen, but they are called in reverse order from panel/connector towards the encoder, which is the "wrong" order. Add a new flag pre_enable_prev_first that any bridge can set to swap the order of pre_enable (and post_disable) for that and the immediately previous bridge. Should the immediately previous bridge also set the pre_enable_prev_first flag, the previous bridge to that will be called before either of those which requested pre_enable_prev_first. eg: - Panel - Bridge 1 - Bridge 2 pre_enable_prev_first - Bridge 3 - Bridge 4 pre_enable_prev_first - Bridge 5 pre_enable_prev_first - Bridge 6 - Encoder Would result in pre_enable's being called as Panel, Bridge 1, Bridge 3, Bridge 2, Bridge 6, Bridge 5, Bridge 4, Encoder. Signed-off-by: Dave Stevenson Tested-by: Frieder Schrempf Reviewed-by: Frieder Schrempf Link: https://lore.kernel.org/r/20221205173328.1395350-5-dave.stevenson@raspberrypi.com Signed-off-by: Maxime Ripard Stable-dep-of: dd9e329af723 ("drm/bridge: ti-sn65dsi83: Fix enable/disable flow to meet spec") Signed-off-by: Sasha Levin --- include/drm/drm_bridge.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include') diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h index 288c6feda5de..6b656ea23b96 100644 --- a/include/drm/drm_bridge.h +++ b/include/drm/drm_bridge.h @@ -768,6 +768,14 @@ struct drm_bridge { * modes. */ bool interlace_allowed; + /** + * @pre_enable_prev_first: The bridge requires that the prev + * bridge @pre_enable function is called before its @pre_enable, + * and conversely for post_disable. This is most frequently a + * requirement for DSI devices which need the host to be initialised + * before the peripheral. + */ + bool pre_enable_prev_first; /** * @ddc: Associated I2C adapter for DDC access, if any. */ -- cgit v1.2.3