[PATCH 3/5] 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 | 32 +++++++++++++++++++++++++++-----
 1 file changed, 27 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_acpi.c b/drivers/gpu/drm/i915/intel_acpi.c
index 5c49cef..47b8bbd 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;
@@ -118,6 +120,25 @@ static void intel_dsm_platform_mux_info(void)
 	ACPI_FREE(pkg);
 }
 
+static void intel_dsm_set_hpd_wakeup(const u8 *guid)
+{
+	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, 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;
@@ -131,11 +152,12 @@ static bool intel_dsm_pci_probe(struct pci_dev *pdev)
 	intel_dsm_priv.dhandle = dhandle;
 
 	if (IS_BROXTON(dev_priv)) {
-		union acpi_object *obj;
-
-		obj = acpi_evaluate_dsm(dhandle, intel_dsm_guid_bxt,
-					INTEL_DSM_REVISION_ID, 0, NULL);
-		if (!obj)
+		if (dev_priv->vbt.hpd_wakeup_enabled &&
+		    acpi_check_dsm(dhandle, intel_dsm_guid_bxt,
+				   INTEL_DSM_REVISION_ID,
+				   1 << INTEL_DSM_SET_HPD_WAKEUP))
+			intel_dsm_set_hpd_wakeup(intel_dsm_guid_bxt);
+		else
 			return false;
 	} else {
 		if (acpi_check_dsm(dhandle, intel_dsm_guid,
-- 
2.7.4