drm/amd/amdgpu: expose fan rpm though hwmon

Only for cards that are supported by powerplay.

Signed-off-by: Grazvydas Ignotas <notasas@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dpm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_dpm.h
index bd85e35..e45bd05 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dpm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dpm.h
@@ -317,6 +317,11 @@ struct amdgpu_dpm_funcs {
 	      (adev)->powerplay.pp_funcs->get_fan_speed_percent((adev)->powerplay.pp_handle, (s)) : \
 	      (adev)->pm.funcs->get_fan_speed_percent((adev), (s)))
 
+#define amdgpu_dpm_get_fan_speed_rpm(adev, s) \
+	((adev)->pp_enabled ?						\
+	      (adev)->powerplay.pp_funcs->get_fan_speed_rpm((adev)->powerplay.pp_handle, (s)) : \
+	      -EINVAL)
+
 #define amdgpu_dpm_get_sclk(adev, l) \
 	((adev)->pp_enabled ?						\
 	      (adev)->powerplay.pp_funcs->get_sclk((adev)->powerplay.pp_handle, (l)) : \