Not all systems expose a firmware or platform mechanism for changing the backlight intensity on i915, so add native driver support.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: David Airlie <airlied@linux.ie>
Cc: Alex Deucher <alexdeucher@gmail.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Tested-by: Sedat Dilek <sedat.dilek@googlemail.com>
Tested-by: Michel Alexandre Salim <salimma@fedoraproject.org>
Tested-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 71 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
index 05f500cd9c24..a9e0c7bcd317 100644
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -277,7 +277,7 @@ void intel_panel_enable_backlight(struct drm_device *dev)
         dev_priv->backlight_enabled = true;
 }
 
-void intel_panel_setup_backlight(struct drm_device *dev)
+static void intel_panel_init_backlight(struct drm_device *dev)
 {
         struct drm_i915_private *dev_priv = dev->dev_private;
 
@@ -309,3 +309,73 @@ intel_panel_detect(struct drm_device *dev)
 
         return connector_status_unknown;
 }
+
+#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
+static int intel_panel_update_status(struct backlight_device *bd)
+{
+        struct drm_device *dev = bl_get_data(bd);
+        intel_panel_set_backlight(dev, bd->props.brightness);
+        return 0;
+}
+
+static int intel_panel_get_brightness(struct backlight_device *bd)
+{
+        struct drm_device *dev = bl_get_data(bd);
+        return intel_panel_get_backlight(dev);
+}
+
+static const struct backlight_ops intel_panel_bl_ops = {
+        .update_status = intel_panel_update_status,
+        .get_brightness = intel_panel_get_brightness,
+};
+
+int intel_panel_setup_backlight(struct drm_device *dev)
+{
+        struct drm_i915_private *dev_priv = dev->dev_private;
+        struct backlight_properties props;
+        struct drm_connector *connector;
+
+        intel_panel_init_backlight(dev);
+
+        if (dev_priv->int_lvds_connector)
+                connector = dev_priv->int_lvds_connector;
+        else if (dev_priv->int_edp_connector)
+                connector = dev_priv->int_edp_connector;
+        else
+                return -ENODEV;
+
+        props.type = BACKLIGHT_RAW;
+        props.max_brightness = intel_panel_get_max_backlight(dev);
+        dev_priv->backlight =
+                backlight_device_register("intel_backlight",
+                                          &connector->kdev, dev,
+                                          &intel_panel_bl_ops, &props);
+
+        if (IS_ERR(dev_priv->backlight)) {
+                DRM_ERROR("Failed to register backlight: %ld\n",
+                          PTR_ERR(dev_priv->backlight));
+                dev_priv->backlight = NULL;
+                return -ENODEV;
+        }
+        dev_priv->backlight->props.brightness = intel_panel_get_backlight(dev);
+        return 0;
+}
+
+void intel_panel_destroy_backlight(struct drm_device *dev)
+{
+        struct drm_i915_private *dev_priv = dev->dev_private;
+        if (dev_priv->backlight)
+                backlight_device_unregister(dev_priv->backlight);
+}
+#else
+int intel_panel_setup_backlight(struct drm_device *dev)
+{
+        intel_panel_init_backlight(dev);
+        return 0;
+}
+
+void intel_panel_destroy_backlight(struct drm_device *dev)
+{
+        return;
+}
+#endif