[Intel-gfx] [PATCH v3 2/9] drm/i915/dg1: OpRegion PCON DG1 MBD config support

[Anshuman Gupta <anshuman.gupta@intel.com>]

DGFX cards support both Add in Card(AIC) and Mother Board Down(MBD)
configs. MBD config requires HOST BIOS GPIO toggling support
in order to enable/disable vram_sr using ACPI OpRegion.

i915 requires to check OpRegion PCON MBD Config bits to
discover whether DG1 Card is MBD config before enabling
vram_sr.

v2:
- Removed IS_DG1() cond from intel_opregion_dg1_mbd_config. [Jani]
- Moved intel_opregion_vram_sr_required() to prev patch.

BSpec: 53440
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Anshuman Gupta <anshuman.gupta@intel.com>
---
 drivers/gpu/drm/i915/display/intel_opregion.c | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_opregion.c b/drivers/gpu/drm/i915/display/intel_opregion.c
index f4a2a02c9ed3..03ae57f05371 100644
--- a/drivers/gpu/drm/i915/display/intel_opregion.c
+++ b/drivers/gpu/drm/i915/display/intel_opregion.c
@@ -55,6 +55,8 @@
 #define MBOX_ASLE_EXT		BIT(4)	/* Mailbox #5 */
 #define MBOX_BACKLIGHT		BIT(5)	/* Mailbox #2 (valid from v3.x) */
 
+#define PCON_DG1_MBD_CONFIG				BIT(9)
+#define PCON_DG1_MBD_CONFIG_FIELD_VALID			BIT(10)
 #define PCON_DGFX_BIOS_SUPPORTS_VRSR			BIT(11)
 #define PCON_DGFX_BIOS_SUPPORTS_VRSR_FIELD_VALID	BIT(12)
 #define PCON_HEADLESS_SKU	BIT(13)
@@ -1257,6 +1259,19 @@ void intel_opregion_unregister(struct drm_i915_private *i915)
 	opregion->lid_state = NULL;
 }
 
+static bool intel_opregion_dg1_mbd_config(struct drm_i915_private *i915)
+{
+	struct intel_opregion *opregion = &i915->opregion;
+
+	if (!opregion->header)
+		return false;
+
+	if (opregion->header->pcon & PCON_DG1_MBD_CONFIG_FIELD_VALID)
+		return opregion->header->pcon & PCON_DG1_MBD_CONFIG;
+	else
+		return false;
+}
+
 /**
  * intel_opregion_vram_sr_required().
  * @i915 i915 device priv data.
@@ -1270,6 +1285,12 @@ void intel_opregion_unregister(struct drm_i915_private *i915)
 bool
 intel_opregion_vram_sr_required(struct drm_i915_private *i915)
 {
+	if (!IS_DGFX(i915))
+		return false;
+
+	if (IS_DG1(i915))
+		return intel_opregion_dg1_mbd_config(i915);
+
 	return false;
 }
 
-- 
2.26.2