drm/dsi: add helper function to find the second host in a

A patch from »drm/rockchip: migrate to common dw-mipi-dsi bridge and dual-dsi« in state Mailinglist for linux-kernel

From: Heiko Stuebner <heiko@...> Date: Fri, 8 Jun 2018 13:08:41 +0200

Commit-Message

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@...>

Patch-Comment

drivers/gpu/drm/drm_mipi_dsi.c | 56 ++++++++++++++++++++++++++++++++++ include/drm/drm_mipi_dsi.h | 2 ++ 2 files changed, 58 insertions(+)

Statistics

  • 58 lines added
  • 0 lines removed

Changes

------------------------ drivers/gpu/drm/drm_mipi_dsi.c ------------------------
index bc73b7f5b9fc..0c3c9c7aa3b8 100644
@@ -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;
-------------------------- include/drm/drm_mipi_dsi.h --------------------------
index 4fef19064b0f..89532ae69c91 100644
@@ -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 */
 
 

Recent Patches

About Us

Sed lacus. Donec lectus. Nullam pretium nibh ut turpis. Nam bibendum. In nulla tortor, elementum vel, tempor at, varius non, purus. Mauris vitae nisl nec metus placerat consectetuer.

Read More...