drm/amdgpu: add new cgs interface to get display info (v2)

Add new CGS interfaces to query display info across modules.
This is nedded by the powerplay module for synchronizing with
the display module.

v2: (agd): fold in refresh rate fix, rebase
Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Reviewed-by: Jammy Zhou <Jammy.Zhou@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -758,6 +758,45 @@ static int amdgpu_cgs_query_system_info(void *cgs_device,
 	return 0;
 }
 
+static int amdgpu_cgs_get_active_displays_info(void *cgs_device,
+					  struct cgs_display_info *info)
+{
+	CGS_FUNC_ADEV;
+	struct amdgpu_crtc *amdgpu_crtc;
+	struct drm_device *ddev = adev->ddev;
+	struct drm_crtc *crtc;
+	uint32_t line_time_us, vblank_lines;
+
+	if (info == NULL)
+		return -EINVAL;
+
+	if (adev->mode_info.num_crtc && adev->mode_info.mode_config_initialized) {
+		list_for_each_entry(crtc,
+				&ddev->mode_config.crtc_list, head) {
+			amdgpu_crtc = to_amdgpu_crtc(crtc);
+			if (crtc->enabled) {
+				info->active_display_mask |= (1 << amdgpu_crtc->crtc_id);
+				info->display_count++;
+			}
+			if (info->mode_info != NULL &&
+				crtc->enabled && amdgpu_crtc->enabled &&
+				amdgpu_crtc->hw_mode.clock) {
+				line_time_us = (amdgpu_crtc->hw_mode.crtc_htotal * 1000) /
+							amdgpu_crtc->hw_mode.clock;
+				vblank_lines = amdgpu_crtc->hw_mode.crtc_vblank_end -
+							amdgpu_crtc->hw_mode.crtc_vdisplay +
+							(amdgpu_crtc->v_border * 2);
+				info->mode_info->vblank_time_us = vblank_lines * line_time_us;
+				info->mode_info->refresh_rate = drm_mode_vrefresh(&amdgpu_crtc->hw_mode);
+				info->mode_info->ref_clock = adev->clock.spll.reference_freq;
+				info->mode_info++;
+			}
+		}
+	}
+
+	return 0;
+}
+
 /** \brief evaluate acpi namespace object, handle or pathname must be valid
  *  \param cgs_device
  *  \param info input/output arguments for the control method
@@ -1006,6 +1045,7 @@ static const struct cgs_ops amdgpu_cgs_ops = {
 	amdgpu_cgs_get_firmware_info,
 	amdgpu_cgs_set_powergating_state,
 	amdgpu_cgs_set_clockgating_state,
+	amdgpu_cgs_get_active_displays_info,
 	amdgpu_cgs_call_acpi_method,
 	amdgpu_cgs_query_system_info,
 };

drivers/gpu/drm/amd/include/cgs_common.h

@@ -142,6 +142,18 @@ struct cgs_firmware_info {
 	void			*kptr;
 };
 
+struct cgs_mode_info {
+	uint32_t		refresh_rate;
+	uint32_t		ref_clock;
+	uint32_t		vblank_time_us;
+};
+
+struct cgs_display_info {
+	uint32_t		display_count;
+	uint32_t		active_display_mask;
+	struct cgs_mode_info *mode_info;
+};
+
 typedef unsigned long cgs_handle_t;
 
 #define CGS_ACPI_METHOD_ATCS          0x53435441
@@ -541,6 +553,10 @@ typedef int(*cgs_set_clockgating_state)(void *cgs_device,
 				  enum amd_ip_block_type block_type,
 				  enum amd_clockgating_state state);
 
+typedef int(*cgs_get_active_displays_info)(
+					void *cgs_device,
+					struct cgs_display_info *info);
+
 typedef int (*cgs_call_acpi_method)(void *cgs_device,
 					uint32_t acpi_method,
 					uint32_t acpi_function,
@@ -592,6 +608,8 @@ struct cgs_ops {
 	/* cg pg interface*/
 	cgs_set_powergating_state set_powergating_state;
 	cgs_set_clockgating_state set_clockgating_state;
+	/* display manager */
+	cgs_get_active_displays_info get_active_displays_info;
 	/* ACPI */
 	cgs_call_acpi_method call_acpi_method;
 	/* get system info */
@@ -682,6 +700,8 @@ struct cgs_device
 	CGS_CALL(set_powergating_state, dev, block_type, state)
 #define cgs_set_clockgating_state(dev, block_type, state)	\
 	CGS_CALL(set_clockgating_state, dev, block_type, state)
+#define cgs_get_active_displays_info(dev, info)	\
+	CGS_CALL(get_active_displays_info, dev, info)
 #define cgs_call_acpi_method(dev, acpi_method, acpi_function, pintput, poutput, output_count, input_size, output_size)	\
 	CGS_CALL(call_acpi_method, dev, acpi_method, acpi_function, pintput, poutput, output_count, input_size, output_size)
 #define cgs_query_system_info(dev, sys_info)	\