diff mbox

[RFC,2/2] drm/i915: override acpi brightness control

Message ID 1275516702-27090-3-git-send-email-kamal@canonical.com
State Deferred, archived
Headers show

Commit Message

Kamal Mostafa June 2, 2010, 10:11 p.m. UTC
None
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/i915_opregion.c b/drivers/gpu/drm/i915/i915_opregion.c
index 7cc8410..a69033e 100644
--- a/drivers/gpu/drm/i915/i915_opregion.c
+++ b/drivers/gpu/drm/i915/i915_opregion.c
@@ -32,6 +32,9 @@ 
 #include "i915_drm.h"
 #include "i915_drv.h"
 
+unsigned int i915_brightness = 1;
+module_param_named(brightness, i915_brightness, int, 0400);
+
 #define PCI_ASLE 0xe4
 #define PCI_LBPC 0xf4
 #define PCI_ASLS 0xfc
@@ -422,6 +425,18 @@  static void intel_didl_outputs(struct drm_device *dev)
 		opregion->acpi->didl[i] = 0;
 }
 
+static unsigned int i915_set_brightness(void *dev, unsigned int brightness)
+{
+        /* Nb. brightness value range is 0 to 255. */
+    	u32 bclp = ASLE_BCLP_VALID | brightness;
+	struct drm_device *drmdev = dev;
+
+	if (IS_IRONLAKE(drmdev))
+	    return asle_set_backlight_ironlake(drmdev, bclp);
+	else
+	    return asle_set_backlight(drmdev, bclp);
+}
+
 int intel_opregion_init(struct drm_device *dev, int resume)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -469,6 +484,10 @@  int intel_opregion_init(struct drm_device *dev, int resume)
 		DRM_DEBUG_DRIVER("ASLE supported\n");
 		opregion->asle = base + OPREGION_ASLE_OFFSET;
 		opregion_enable_asle(dev);
+	        /* Register the i915-based brightness control with ACPI */
+		if (!resume && i915_brightness)
+			acpi_brightness_hook_register("i915",
+					i915_set_brightness, dev, 255);
 	}
 
 	if (!resume)