drm/i915/dmc: Load DMC on DG2

Add Support for DC states on Dg2.

v2: Add dc9 as the max supported DC states and disable DC5.
v3: set max_dc to 0. (Imre)

Cc: Imre Deak <imre.deak@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>(v1)
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220504202213.740200-2-anusha.srivatsa@intel.com

drivers/gpu/drm/i915/display/intel_display_power.c

@@ -907,7 +907,9 @@ static u32 get_allowed_dc_mask(const struct drm_i915_private *dev_priv,
 	if (!HAS_DISPLAY(dev_priv))
 		return 0;
 
-	if (IS_DG1(dev_priv))
+	if (IS_DG2(dev_priv))
+		max_dc = 0;
+	else if (IS_DG1(dev_priv))
 		max_dc = 3;
 	else if (DISPLAY_VER(dev_priv) >= 12)
 		max_dc = 4;

drivers/gpu/drm/i915/display/intel_dmc.c

@@ -52,6 +52,10 @@
 
 #define DISPLAY_VER12_DMC_MAX_FW_SIZE	ICL_DMC_MAX_FW_SIZE
 
+#define DG2_DMC_PATH			DMC_PATH(dg2, 2, 06)
+#define DG2_DMC_VERSION_REQUIRED	DMC_VERSION(2, 06)
+MODULE_FIRMWARE(DG2_DMC_PATH);
+
 #define ADLP_DMC_PATH			DMC_PATH(adlp, 2, 16)
 #define ADLP_DMC_VERSION_REQUIRED	DMC_VERSION(2, 16)
 MODULE_FIRMWARE(ADLP_DMC_PATH);
@@ -688,7 +692,11 @@ void intel_dmc_ucode_init(struct drm_i915_private *dev_priv)
 	 */
 	intel_dmc_runtime_pm_get(dev_priv);
 
-	if (IS_ALDERLAKE_P(dev_priv)) {
+	if (IS_DG2(dev_priv)) {
+		dmc->fw_path = DG2_DMC_PATH;
+		dmc->required_version = DG2_DMC_VERSION_REQUIRED;
+		dmc->max_fw_size = DISPLAY_VER13_DMC_MAX_FW_SIZE;
+	} else if (IS_ALDERLAKE_P(dev_priv)) {
 		dmc->fw_path = ADLP_DMC_PATH;
 		dmc->required_version = ADLP_DMC_VERSION_REQUIRED;
 		dmc->max_fw_size = DISPLAY_VER13_DMC_MAX_FW_SIZE;