drm/i915: Use the VBT from OpRegion when available (v3)

It is recommended that we use the Video BIOS tables that were copied
into the OpRegion during POST when initialising the driver. This saves
us from having to furtle around inside the ROM ourselves and possibly
allows the vBIOS to adjust the tables prior to initialisation.

On some systems, such as the Samsung N210, there is no accessible VBIOS
and the only means of finding the VBT is through the OpRegion.

v2: Rearrange the code so that ASLE is enabled along with ACPI
v3: Enable OpRegion parsing even without ACPI

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Garrett <mjg@redhat.com>

1 files changed, 58 insertions, 55 deletions

diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c
index 97d5329079f..3cb13237ba5 100644
--- a/drivers/gpu/drm/i915/intel_opregion.c
+++ b/drivers/gpu/drm/i915/intel_opregion.c
@@ -36,12 +36,11 @@
 #define PCI_LBPC 0xf4
 #define PCI_ASLS 0xfc
 
-#define OPREGION_SZ            (8*1024)
 #define OPREGION_HEADER_OFFSET 0
 #define OPREGION_ACPI_OFFSET   0x100
 #define OPREGION_SWSCI_OFFSET  0x200
 #define OPREGION_ASLE_OFFSET   0x300
-#define OPREGION_VBT_OFFSET    0x1000
+#define OPREGION_VBT_OFFSET    0x400
 
 #define OPREGION_SIGNATURE "IntelGraphicsMem"
 #define MBOX_ACPI      (1<<0)
@@ -143,6 +142,7 @@ struct opregion_asle {
 #define ACPI_DIGITAL_OUTPUT (3<<8)
 #define ACPI_LVDS_OUTPUT (4<<8)
 
+#ifdef CONFIG_ACPI
 static u32 asle_set_backlight(struct drm_device *dev, u32 bclp)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -465,7 +465,58 @@ blind_set:
 	goto end;
 }
 
-int intel_opregion_init(struct drm_device *dev, int resume)
+void intel_opregion_init(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_opregion *opregion = &dev_priv->opregion;
+
+	if (!opregion->header)
+		return;
+
+	if (opregion->acpi) {
+		if (drm_core_check_feature(dev, DRIVER_MODESET))
+			intel_didl_outputs(dev);
+
+		/* Notify BIOS we are ready to handle ACPI video ext notifs.
+		 * Right now, all the events are handled by the ACPI video module.
+		 * We don't actually need to do anything with them. */
+		opregion->acpi->csts = 0;
+		opregion->acpi->drdy = 1;
+
+		system_opregion = opregion;
+		register_acpi_notifier(&intel_opregion_notifier);
+	}
+
+	if (opregion->asle)
+		intel_opregion_enable_asle(dev);
+}
+
+void intel_opregion_fini(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_opregion *opregion = &dev_priv->opregion;
+
+	if (!opregion->header)
+		return;
+
+	if (opregion->acpi) {
+		opregion->acpi->drdy = 0;
+
+		system_opregion = NULL;
+		unregister_acpi_notifier(&intel_opregion_notifier);
+	}
+
+	/* just clear all opregion memory pointers now */
+	iounmap(opregion->header);
+	opregion->header = NULL;
+	opregion->acpi = NULL;
+	opregion->swsci = NULL;
+	opregion->asle = NULL;
+	opregion->vbt = NULL;
+}
+#endif
+
+int intel_opregion_setup(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_opregion *opregion = &dev_priv->opregion;
@@ -480,29 +531,23 @@ int intel_opregion_init(struct drm_device *dev, int resume)
 		return -ENOTSUPP;
 	}
 
-	base = ioremap(asls, OPREGION_SZ);
+	base = ioremap(asls, OPREGION_SIZE);
 	if (!base)
 		return -ENOMEM;
 
-	opregion->header = base;
-	if (memcmp(opregion->header->signature, OPREGION_SIGNATURE, 16)) {
+	if (memcmp(base, OPREGION_SIGNATURE, 16)) {
 		DRM_DEBUG_DRIVER("opregion signature mismatch\n");
 		err = -EINVAL;
 		goto err_out;
 	}
+	opregion->header = base;
+	opregion->vbt = base + OPREGION_VBT_OFFSET;
 
 	mboxes = opregion->header->mboxes;
 	if (mboxes & MBOX_ACPI) {
 		DRM_DEBUG_DRIVER("Public ACPI methods supported\n");
 		opregion->acpi = base + OPREGION_ACPI_OFFSET;
-		if (drm_core_check_feature(dev, DRIVER_MODESET))
-			intel_didl_outputs(dev);
-	} else {
-		DRM_DEBUG_DRIVER("Public ACPI methods not supported\n");
-		err = -ENOTSUPP;
-		goto err_out;
 	}
-	opregion->enabled = 1;
 
 	if (mboxes & MBOX_SWSCI) {
 		DRM_DEBUG_DRIVER("SWSCI supported\n");
@@ -511,53 +556,11 @@ int intel_opregion_init(struct drm_device *dev, int resume)
 	if (mboxes & MBOX_ASLE) {
 		DRM_DEBUG_DRIVER("ASLE supported\n");
 		opregion->asle = base + OPREGION_ASLE_OFFSET;
-		intel_opregion_enable_asle(dev);
 	}
 
-	if (!resume)
-		acpi_video_register();
-
-
-	/* Notify BIOS we are ready to handle ACPI video ext notifs.
-	 * Right now, all the events are handled by the ACPI video module.
-	 * We don't actually need to do anything with them. */
-	opregion->acpi->csts = 0;
-	opregion->acpi->drdy = 1;
-
-	system_opregion = opregion;
-	register_acpi_notifier(&intel_opregion_notifier);
-
 	return 0;
 
 err_out:
 	iounmap(opregion->header);
-	opregion->header = NULL;
-	acpi_video_register();
 	return err;
 }
-
-void intel_opregion_free(struct drm_device *dev, int suspend)
-{
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	struct intel_opregion *opregion = &dev_priv->opregion;
-
-	if (!opregion->enabled)
-		return;
-
-	if (!suspend)
-		acpi_video_unregister();
-
-	opregion->acpi->drdy = 0;
-
-	system_opregion = NULL;
-	unregister_acpi_notifier(&intel_opregion_notifier);
-
-	/* just clear all opregion memory pointers now */
-	iounmap(opregion->header);
-	opregion->header = NULL;
-	opregion->acpi = NULL;
-	opregion->swsci = NULL;
-	opregion->asle = NULL;
-
-	opregion->enabled = 0;
-}