video: Track whether a display is in use

Mark a display as in use when display_enable() is called. This can avoid
a display being used by multiple video-output devices.

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/drivers/video/display-uclass.c b/drivers/video/display-uclass.c
index e4763de..e752eb0 100644 (file)
--- a/drivers/video/display-uclass.c
+++ b/drivers/video/display-uclass.c
@@ -23,10 +23,19 @@ int display_enable(struct udevice *dev, int panel_bpp,
                        const struct display_timing *timing)
 {
        struct dm_display_ops *ops = display_get_ops(dev);
+       struct display_plat *disp_uc_plat;
+       int ret;
 
        if (!ops || !ops->enable)
                return -ENOSYS;
-       return ops->enable(dev, panel_bpp, timing);
+       ret = ops->enable(dev, panel_bpp, timing);
+       if (ret)
+               return ret;
+
+       disp_uc_plat = dev_get_uclass_platdata(dev);
+       disp_uc_plat->in_use = true;
+
+       return 0;
 }
 
 int display_read_timing(struct udevice *dev, struct display_timing *timing)
@@ -48,6 +57,13 @@ int display_read_timing(struct udevice *dev, struct display_timing *timing)
        return edid_get_timing(buf, ret, timing, &panel_bits_per_colour);
 }
 
+bool display_in_use(struct udevice *dev)
+{
+       struct display_plat *disp_uc_plat = dev_get_uclass_platdata(dev);
+
+       return disp_uc_plat->in_use;
+}
+
 UCLASS_DRIVER(display) = {
        .id             = UCLASS_DISPLAY,
        .name           = "display",

diff --git a/include/display.h b/include/display.h
index b1c4766..d0a08d4 100644 (file)
--- a/include/display.h
+++ b/include/display.h
@@ -16,10 +16,12 @@ struct display_timing;
  * @source_id: ID for the source of the display data, typically a video
  * controller
  * @src_dev:   Source device providing the video
+ * @in_use:    Display is being used
  */
 struct display_plat {
        int source_id;
        struct udevice *src_dev;
+       bool in_use;
 };
 
 /**
@@ -41,6 +43,14 @@ int display_read_timing(struct udevice *dev, struct display_timing *timing);
 int display_enable(struct udevice *dev, int panel_bpp,
                   const struct display_timing *timing);
 
+/**
+ * display_in_use() - Check if a display is in use by any device
+ *
+ * @return true if the device is in use (display_enable() has been called
+ * successfully), else false
+ */
+bool display_in_use(struct udevice *dev);
+
 struct dm_display_ops {
        /**
         * read_timing() - Read information directly