From a specified output port of one dsi controller this function allows to
iterate over the list of registered dsi controllers trying to find a second instance connected to the same display, like it is used in dual-dsi setups.
Signed-off-by: Heiko Stuebner heiko@sntech.de --- drivers/gpu/drm/drm_mipi_dsi.c | 56 ++++++++++++++++++++++++++++++++++ include/drm/drm_mipi_dsi.h | 2 ++ 2 files changed, 58 insertions(+)
diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c index bc73b7f5b9fc..0c3c9c7aa3b8 100644 --- a/drivers/gpu/drm/drm_mipi_dsi.c +++ b/drivers/gpu/drm/drm_mipi_dsi.c @@ -30,6 +30,7 @@ #include <linux/device.h> #include <linux/module.h> #include <linux/of_device.h> +#include <linux/of_graph.h> #include <linux/pm_runtime.h> #include <linux/slab.h>
@@ -282,6 +283,61 @@ struct mipi_dsi_host *of_find_mipi_dsi_host_by_node(struct device_node *node) } EXPORT_SYMBOL(of_find_mipi_dsi_host_by_node);
+struct device_node *of_mipi_dsi_find_second_host(struct device_node *first_np, + int port, int endpoint) +{ + struct mipi_dsi_host *first, *host; + struct device_node *remote, *np, *second_np = NULL; + int num = 0; + + first = of_find_mipi_dsi_host_by_node(first_np); + if (!first) { + pr_err("no dsi-host for node %s\n", first_np->full_name); + return ERR_PTR(-ENODEV); + } + + /* output-node of the known dsi-host */ + remote = of_graph_get_remote_node(first_np, port, endpoint); + if (!remote) { + dev_err(first->dev, "no output node found\n"); + return ERR_PTR(-ENODEV); + } + + mutex_lock(&host_lock); + + list_for_each_entry(host, &host_list, list) { + np = of_graph_get_remote_node(host->dev->of_node, + port, endpoint); + + /* found a host connected to this panel */ + if (np == remote) + num++; + + /* found one second host */ + if (host->dev->of_node != first_np) + second_np = host->dev->of_node; + + of_node_put(np); + } + + /* of_node_get the node under host_lock */ + if (num == 2) + of_node_get(second_np); + + mutex_unlock(&host_lock); + + of_node_put(remote); + + if (num > 2) { + dev_err(first->dev, + "too many DSI links for output: %d links\n", num); + return ERR_PTR(-EINVAL); + } + + return second_np; +} +EXPORT_SYMBOL(of_mipi_dsi_find_second_host); + int mipi_dsi_host_register(struct mipi_dsi_host *host) { struct device_node *node; diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h index 4fef19064b0f..89532ae69c91 100644 --- a/include/drm/drm_mipi_dsi.h +++ b/include/drm/drm_mipi_dsi.h @@ -107,6 +107,8 @@ struct mipi_dsi_host { int mipi_dsi_host_register(struct mipi_dsi_host *host); void mipi_dsi_host_unregister(struct mipi_dsi_host *host); struct mipi_dsi_host *of_find_mipi_dsi_host_by_node(struct device_node *node); +struct device_node *of_mipi_dsi_find_second_host(struct device_node *first_np, + int port, int endpoint);
/* DSI mode flags */