drm/amd/pp: Add a helper to convert VID to voltage value

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/powerplay/hwmgr/hwmgr.c

@@ -60,6 +60,11 @@ uint8_t convert_to_vid(uint16_t vddc)
 	return (uint8_t) ((6200 - (vddc * VOLTAGE_SCALE)) / 25);
 }
 
+uint16_t convert_to_vddc(uint8_t vid)
+{
+	return (uint16_t) ((6200 - (vid * 25)) / VOLTAGE_SCALE);
+}
+
 static int phm_get_pci_bus_devfn(struct pp_hwmgr *hwmgr,
 		struct cgs_system_info *sys_info)
 {

drivers/gpu/drm/amd/powerplay/inc/hwmgr.h

@@ -42,6 +42,7 @@ struct pp_atomctrl_voltage_table;
 #define VOLTAGE_SCALE 4
 
 uint8_t convert_to_vid(uint16_t vddc);
+uint16_t convert_to_vddc(uint8_t vid);
 
 enum DISPLAY_GAP {
 	DISPLAY_GAP_VBLANK_OR_WM = 0,   /* Wait for vblank or MCHG watermark. */