drm/omap: Support for HDMI hot plug detection

The HPD signal can be used for detecting HDMI cable plug and unplug event
without the need for polling the status of the line.
This will speed up detecting such event because we do not need to wait for
the next poll event to notice the state change.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

1 files changed, 29 insertions, 0 deletions

diff --git a/drivers/gpu/drm/omapdrm/omap_drv.c b/drivers/gpu/drm/omapdrm/omap_drv.c
index 721a358531b0..10e24ca928f2 100644
--- a/drivers/gpu/drm/omapdrm/omap_drv.c
+++ b/drivers/gpu/drm/omapdrm/omap_drv.c
@@ -324,6 +324,32 @@ static int omap_modeset_init(struct drm_device *dev)
 }
 
 /*
+ * Enable the HPD in external components if supported
+ */
+static void omap_modeset_enable_external_hpd(void)
+{
+        struct omap_dss_device *dssdev = NULL;
+
+        for_each_dss_dev(dssdev) {
+                if (dssdev->driver->enable_hpd)
+                        dssdev->driver->enable_hpd(dssdev);
+        }
+}
+
+/*
+ * Disable the HPD in external components if supported
+ */
+static void omap_modeset_disable_external_hpd(void)
+{
+        struct omap_dss_device *dssdev = NULL;
+
+        for_each_dss_dev(dssdev) {
+                if (dssdev->driver->disable_hpd)
+                        dssdev->driver->disable_hpd(dssdev);
+        }
+}
+
+/*
  * drm ioctl funcs
  */
 
@@ -602,6 +628,7 @@ static int pdev_probe(struct platform_device *pdev)
         priv->fbdev = omap_fbdev_init(ddev);
 
         drm_kms_helper_poll_init(ddev);
+        omap_modeset_enable_external_hpd();
 
         /*
          * Register the DRM device with the core and the connectors with
@@ -614,6 +641,7 @@ static int pdev_probe(struct platform_device *pdev)
         return 0;
 
 err_cleanup_helpers:
+        omap_modeset_disable_external_hpd();
         drm_kms_helper_poll_fini(ddev);
         if (priv->fbdev)
                 omap_fbdev_free(ddev);
@@ -642,6 +670,7 @@ static int pdev_remove(struct platform_device *pdev)
 
         drm_dev_unregister(ddev);
 
+        omap_modeset_disable_external_hpd();
         drm_kms_helper_poll_fini(ddev);
 
         if (priv->fbdev)