diff options
Diffstat (limited to 'drivers/gpu/drm/drm_of.c')
| -rw-r--r-- | drivers/gpu/drm/drm_of.c | 51 |
1 files changed, 51 insertions, 0 deletions
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 <drm/drm_crtc.h> #include <drm/drm_device.h> #include <drm/drm_encoder.h> +#include <drm/drm_mipi_dsi.h> #include <drm/drm_of.h> #include <drm/drm_panel.h> @@ -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 */ |