[Intel-gfx] [PATCH 2/6] drm/i915/bxt: Added _DSM call to set HPD_CTL.

[Animesh Manna]

_DSM is added to program HPD_CTL(0x1094) register
of PMC from i915 driver which will be called
based on driver feature flag. PMC hpd control register
programming will enable PMC to get hpd interrupt
during dc9.

Signed-off-by: Animesh Manna <animesh.manna at intel.com>
---
 drivers/gpu/drm/i915/intel_acpi.c | 45 +++++++++++++++++++++++++++++++++------
 1 file changed, 38 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_acpi.c b/drivers/gpu/drm/i915/intel_acpi.c
index eb638a1..8f3d672 100644
--- a/drivers/gpu/drm/i915/intel_acpi.c
+++ b/drivers/gpu/drm/i915/intel_acpi.c
@@ -10,6 +10,8 @@
 
 #define INTEL_DSM_REVISION_ID 1 /* For Calpella anyway... */
 #define INTEL_DSM_FN_PLATFORM_MUX_INFO 1 /* No args */
+#define INTEL_DSM_SET_HPD_WAKEUP 17
+#define HPD_WAKEUP_EN_VAL 0xFCF0
 
 static struct intel_dsm_priv {
 	acpi_handle dhandle;
@@ -110,23 +112,52 @@ static void intel_dsm_platform_mux_info(void)
 	ACPI_FREE(pkg);
 }
 
+static void intel_dsm_set_hpd_wakeup(void)
+{
+	union acpi_object *obj;
+	union acpi_object argv4 = {
+		.integer.type = ACPI_TYPE_INTEGER,
+		.integer.value = HPD_WAKEUP_EN_VAL,
+	};
+
+	obj = acpi_evaluate_dsm_typed(intel_dsm_priv.dhandle, intel_dsm_guid,
+			INTEL_DSM_REVISION_ID, INTEL_DSM_SET_HPD_WAKEUP,
+			&argv4, ACPI_TYPE_INTEGER);
+
+	if (!obj)
+		DRM_DEBUG_DRIVER("failed to evaluate _DSM\n");
+
+	ACPI_FREE(obj);
+}
+
 static bool intel_dsm_pci_probe(struct pci_dev *pdev)
 {
 	acpi_handle dhandle;
+	struct drm_device *dev = pci_get_drvdata(pdev);
+	struct drm_i915_private *dev_priv = dev->dev_private;
 
 	dhandle = ACPI_HANDLE(&pdev->dev);
-	if (!dhandle)
-		return false;
 
-	if (!acpi_check_dsm(dhandle, intel_dsm_guid, INTEL_DSM_REVISION_ID,
-			    1 << INTEL_DSM_FN_PLATFORM_MUX_INFO)) {
-		DRM_DEBUG_KMS("no _DSM method for intel device\n");
+	if (!dhandle)
 		return false;
-	}
 
 	intel_dsm_priv.dhandle = dhandle;
-	intel_dsm_platform_mux_info();
 
+	if (acpi_check_dsm(dhandle, intel_dsm_guid, INTEL_DSM_REVISION_ID,
+			    1 << INTEL_DSM_FN_PLATFORM_MUX_INFO))
+		intel_dsm_platform_mux_info();
+	else
+		DRM_DEBUG_KMS("no _DSM method for mux-info\n");
+
+	/* Need to ensure vbt parsing is completed. */
+	if (dev_priv->vbt.hpd_wakeup_enabled &&
+		acpi_check_dsm(dhandle, intel_dsm_guid, INTEL_DSM_REVISION_ID,
+			    1 << INTEL_DSM_SET_HPD_WAKEUP))
+		intel_dsm_set_hpd_wakeup();
+	else {
+		dev_priv->vbt.hpd_wakeup_enabled = false;
+		DRM_DEBUG_KMS("no _DSM method for hpd-enabling\n");
+	}
 	return true;
 }
 
-- 
2.0.2