From 19ff997ffc43cb203fb7d6ac169b69e26c7dcbfb Mon Sep 17 00:00:00 2001 From: Chris Morgan Date: Mon, 23 Jan 2023 09:46:00 -0600 Subject: [PATCH] drm: of: Add drm_of_get_dsi_bus helper function Add helper function to find DSI host for devices where DSI panel is not a minor of a DSI bus (such as the Samsung AMS495QA01 panel or the official Raspberry Pi touchscreen display). Co-developed-by: Maya Matuszczyk Signed-off-by: Maya Matuszczyk Signed-off-by: Chris Morgan Reviewed-by: Maxime Ripard Signed-off-by: Linus Walleij Link: https://patchwork.freedesktop.org/patch/msgid/20230123154603.1315112-2-macroalpha82@gmail.com --- drivers/gpu/drm/drm_of.c | 51 ++++++++++++++++++++++++++++++++++++++++ include/drm/drm_of.h | 12 ++++++++++ 2 files changed, 63 insertions(+) diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c index 7bbcb999bb75..177b600895d3 100644 --- a/drivers/gpu/drm/drm_of.c +++ b/drivers/gpu/drm/drm_of.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include @@ -493,3 +494,53 @@ int drm_of_get_data_lanes_count_ep(const struct device_node *port, return ret; } EXPORT_SYMBOL_GPL(drm_of_get_data_lanes_count_ep); + +#if IS_ENABLED(CONFIG_DRM_MIPI_DSI) + +/** + * drm_of_get_dsi_bus - find the DSI bus for a given device + * @dev: parent device of display (SPI, I2C) + * + * Gets parent DSI bus for a DSI device controlled through a bus other + * than MIPI-DCS (SPI, I2C, etc.) using the Device Tree. + * + * Returns pointer to mipi_dsi_host if successful, -EINVAL if the + * request is unsupported, -EPROBE_DEFER if the DSI host is found but + * not available, or -ENODEV otherwise. + */ +struct mipi_dsi_host *drm_of_get_dsi_bus(struct device *dev) +{ + struct mipi_dsi_host *dsi_host; + struct device_node *endpoint, *dsi_host_node; + + /* + * Get first endpoint child from device. + */ + endpoint = of_graph_get_next_endpoint(dev->of_node, NULL); + if (!endpoint) + return ERR_PTR(-ENODEV); + + /* + * Follow the first endpoint to get the DSI host node and then + * release the endpoint since we no longer need it. + */ + dsi_host_node = of_graph_get_remote_port_parent(endpoint); + of_node_put(endpoint); + if (!dsi_host_node) + return ERR_PTR(-ENODEV); + + /* + * Get the DSI host from the DSI host node. If we get an error + * or the return is null assume we're not ready to probe just + * yet. Release the DSI host node since we're done with it. + */ + dsi_host = of_find_mipi_dsi_host_by_node(dsi_host_node); + of_node_put(dsi_host_node); + if (IS_ERR_OR_NULL(dsi_host)) + return ERR_PTR(-EPROBE_DEFER); + + return dsi_host; +} +EXPORT_SYMBOL_GPL(drm_of_get_dsi_bus); + +#endif /* CONFIG_DRM_MIPI_DSI */ diff --git a/include/drm/drm_of.h b/include/drm/drm_of.h index 10ab58c40746..082a6e980d01 100644 --- a/include/drm/drm_of.h +++ b/include/drm/drm_of.h @@ -15,6 +15,8 @@ struct drm_encoder; struct drm_panel; struct drm_bridge; struct device_node; +struct mipi_dsi_device_info; +struct mipi_dsi_host; /** * enum drm_lvds_dual_link_pixels - Pixel order of an LVDS dual-link connection @@ -129,6 +131,16 @@ drm_of_get_data_lanes_count_ep(const struct device_node *port, } #endif +#if IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_DRM_MIPI_DSI) +struct mipi_dsi_host *drm_of_get_dsi_bus(struct device *dev); +#else +static inline struct +mipi_dsi_host *drm_of_get_dsi_bus(struct device *dev) +{ + return ERR_PTR(-EINVAL); +} +#endif /* CONFIG_OF && CONFIG_DRM_MIPI_DSI */ + /* * drm_of_panel_bridge_remove - remove panel bridge * @np: device tree node containing panel bridge output ports