Revert "drm/amdgpu: Revert "drm/amdgpu: getting fan speed pwm for vega10 properly""

This reverts commit 4545ae2e.

The origin patch "drm/amdgpu: getting fan speed pwm for vega10 properly" works fine.
Test failure is caused by test case self.
Signed-off-by: Asher Song <Asher.Song@amd.com>
Reviewed-by: Guchun Chen <guchun.chen@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega10_thermal.c

@@ -67,22 +67,21 @@ int vega10_fan_ctrl_get_fan_speed_info(struct pp_hwmgr *hwmgr,
 int vega10_fan_ctrl_get_fan_speed_pwm(struct pp_hwmgr *hwmgr,
 		uint32_t *speed)
 {
-	uint32_t current_rpm;
-	uint32_t percent = 0;
-
-	if (hwmgr->thermal_controller.fanInfo.bNoFan)
-		return 0;
+	struct amdgpu_device *adev = hwmgr->adev;
+	uint32_t duty100, duty;
+	uint64_t tmp64;
 
-	if (vega10_get_current_rpm(hwmgr, &current_rpm))
-		return -1;
+	duty100 = REG_GET_FIELD(RREG32_SOC15(THM, 0, mmCG_FDO_CTRL1),
+				CG_FDO_CTRL1, FMAX_DUTY100);
+	duty = REG_GET_FIELD(RREG32_SOC15(THM, 0, mmCG_THERMAL_STATUS),
+				CG_THERMAL_STATUS, FDO_PWM_DUTY);
 
-	if (hwmgr->thermal_controller.
-			advanceFanControlParameters.usMaxFanRPM != 0)
-		percent = current_rpm * 255 /
-			hwmgr->thermal_controller.
-			advanceFanControlParameters.usMaxFanRPM;
+	if (!duty100)
+		return -EINVAL;
 
-	*speed = MIN(percent, 255);
+	tmp64 = (uint64_t)duty * 255;
+	do_div(tmp64, duty100);
+	*speed = MIN((uint32_t)tmp64, 255);
 
 	return 0;
 }