drm/amdgpu: Power down acp if board uses AZ (v2)

if board uses AZ rather than ACP, we power down acp
through smu to save power.

v2: handle S3/S4 and hw_fini (Alex)
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c

@@ -289,10 +289,12 @@ static int acp_hw_init(void *handle)
 	r = amd_acp_hw_init(adev->acp.cgs_device,
 			    ip_block->version->major, ip_block->version->minor);
 	/* -ENODEV means board uses AZ rather than ACP */
-	if (r == -ENODEV)
+	if (r == -ENODEV) {
+		amdgpu_dpm_set_powergating_by_smu(adev, AMD_IP_BLOCK_TYPE_ACP, true);
 		return 0;
-	else if (r)
+	} else if (r) {
 		return r;
+	}
 
 	if (adev->rmmio_size == 0 || adev->rmmio_size < 0x5289)
 		return -EINVAL;
@@ -497,8 +499,10 @@ static int acp_hw_fini(void *handle)
 	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
 
 	/* return early if no ACP */
-	if (!adev->acp.acp_cell)
+	if (!adev->acp.acp_cell) {
+		amdgpu_dpm_set_powergating_by_smu(adev, AMD_IP_BLOCK_TYPE_ACP, false);
 		return 0;
+	}
 
 	/* Assert Soft reset of ACP */
 	val = cgs_read_register(adev->acp.cgs_device, mmACP_SOFT_RESET);
@@ -556,11 +560,21 @@ static int acp_hw_fini(void *handle)
 
 static int acp_suspend(void *handle)
 {
+	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
+
+	/* power up on suspend */
+	if (!adev->acp.acp_cell)
+		amdgpu_dpm_set_powergating_by_smu(adev, AMD_IP_BLOCK_TYPE_ACP, false);
 	return 0;
 }
 
 static int acp_resume(void *handle)
 {
+	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
+
+	/* power down again on resume */
+	if (!adev->acp.acp_cell)
+		amdgpu_dpm_set_powergating_by_smu(adev, AMD_IP_BLOCK_TYPE_ACP, true);
 	return 0;
 }