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| author | Boris Brezillon <boris.brezillon@collabora.com> | 2019-12-03 15:15:10 +0100 |
|---|---|---|
| committer | Boris Brezillon <boris.brezillon@collabora.com> | 2019-12-09 10:03:29 +0100 |
| commit | ac877c64c87aff5d228cf53e40d8f68899afa815 (patch) | |
| tree | 9e5959b7ca4e7f9e23cbbac1e6b33bc7463aa731 /include/drm/drm_bridge.h | |
| parent | 4ec5c9050a496a984ffdaaf2307aef353634dc87 (diff) | |
| download | lwn-ac877c64c87aff5d228cf53e40d8f68899afa815.tar.gz lwn-ac877c64c87aff5d228cf53e40d8f68899afa815.zip | |
drm/bridge: Add the drm_bridge_get_prev_bridge() helper
The drm_bridge_get_prev_bridge() helper will be useful for bridge
drivers that want to do bus format negotiation with their neighbours.
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191203141515.3597631-7-boris.brezillon@collabora.com
Diffstat (limited to 'include/drm/drm_bridge.h')
| -rw-r--r-- | include/drm/drm_bridge.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h index 1eb854025a20..bfb0385163f1 100644 --- a/include/drm/drm_bridge.h +++ b/include/drm/drm_bridge.h @@ -427,6 +427,22 @@ drm_bridge_get_next_bridge(struct drm_bridge *bridge) } /** + * drm_bridge_get_prev_bridge() - Get the previous bridge in the chain + * @bridge: bridge object + * + * RETURNS: + * the previous bridge in the chain, or NULL if @bridge is the first. + */ +static inline struct drm_bridge * +drm_bridge_get_prev_bridge(struct drm_bridge *bridge) +{ + if (list_is_first(&bridge->chain_node, &bridge->encoder->bridge_chain)) + return NULL; + + return list_prev_entry(bridge, chain_node); +} + +/** * drm_bridge_chain_get_first_bridge() - Get the first bridge in the chain * @encoder: encoder object * |