From: Chris Morgan <macromorgan@xxxxxxxxxxx>
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).
Signed-off-by: Chris Morgan <macromorgan@xxxxxxxxxxx>
Signed-off-by: Maya Matuszczyk <maccraft123mc@xxxxxxxxx>
---
drivers/gpu/drm/drm_of.c | 70 ++++++++++++++++++++++++++++++++++++++++
include/drm/drm_of.h | 10 ++++++
2 files changed, 80 insertions(+)
diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c
index 7bbcb999bb75..4ebb5bc4b595 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 +494,72 @@ 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);
+
+/**
+ * drm_of_get_dsi_bus - find the DSI bus for a given device
+ * @dev: parent device of display (SPI, I2C)
+ * @info: DSI device info to be updated with correct DSI node
+ *
+ * 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_device_info *info)
+{
+ struct mipi_dsi_host *dsi_host;
+ struct device_node *endpoint, *dsi_host_node;
+
+ /*
+ * Exit immediately if we attempt to call this function when
+ * DRM_MIPI_DSI is not enabled, in the event CONFIG_OF is
+ * enabled.
+ */
+ if (!IS_ENABLED(CONFIG_DRM_MIPI_DSI))
+ return ERR_PTR(-EINVAL);
+
+ /*
+ * 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.
+ */
+ dsi_host_node = of_graph_get_remote_port_parent(endpoint);
+ if (!dsi_host_node)
+ goto error;
+
+ /*
+ * 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)) {
+ of_node_put(endpoint);
+ return ERR_PTR(-EPROBE_DEFER);
+ }
+
+ /*
+ * Set the node of the mipi_dsi_device_info to the correct node
+ * and then release the endpoint node since we're done with it.
+ */
+ info->node = of_graph_get_remote_port(endpoint);
+ if (IS_ERR_OR_NULL(info->node))
+ goto error;
+
+ of_node_put(endpoint);
+ return dsi_host;
+
+error:
+ of_node_put(endpoint);
+ return ERR_PTR(-ENODEV);
+}
+EXPORT_SYMBOL_GPL(drm_of_get_dsi_bus);
diff --git a/include/drm/drm_of.h b/include/drm/drm_of.h
index 10ab58c40746..705ea2caa494 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
@@ -56,6 +58,8 @@ int drm_of_get_data_lanes_count_ep(const struct device_node *port,
int port_reg, int reg,
const unsigned int min,
const unsigned int max);
+struct mipi_dsi_host *drm_of_get_dsi_bus(struct device *dev,
+ struct mipi_dsi_device_info *info);
#else
static inline uint32_t drm_of_crtc_port_mask(struct drm_device *dev,
struct device_node *port)
@@ -127,6 +131,12 @@ drm_of_get_data_lanes_count_ep(const struct device_node *port,
{
return -EINVAL;
}
+static inline struct
+mipi_dsi_host *drm_of_get_dsi_bus(struct device *dev,
+ struct mipi_dsi_device_info *info)
+{
+ return ERR_PTR(-EINVAL);
+}
#endif
/*
--
2.34.1
