drm/radeon/dpm: add pcie gen helper function

Add a helper function to determine the preferred
pcie gen based on the card, system, and circumstance.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 23 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/r600_dpm.c b/drivers/gpu/drm/radeon/r600_dpm.c
index 2e5ec65a78f7..28177da694f2 100644
--- a/drivers/gpu/drm/radeon/r600_dpm.c
+++ b/drivers/gpu/drm/radeon/r600_dpm.c
@@ -997,3 +997,26 @@ void r600_free_extended_power_table(struct radeon_device *rdev)
         if (rdev->pm.dpm.dyn_state.ppm_table)
                 kfree(rdev->pm.dpm.dyn_state.ppm_table);
 }
+
+enum radeon_pcie_gen r600_get_pcie_gen_support(struct radeon_device *rdev,
+                                               u32 sys_mask,
+                                               enum radeon_pcie_gen asic_gen,
+                                               enum radeon_pcie_gen default_gen)
+{
+        switch (asic_gen) {
+        case RADEON_PCIE_GEN1:
+                return RADEON_PCIE_GEN1;
+        case RADEON_PCIE_GEN2:
+                return RADEON_PCIE_GEN2;
+        case RADEON_PCIE_GEN3:
+                return RADEON_PCIE_GEN3;
+        default:
+                if ((sys_mask & DRM_PCIE_SPEED_80) && (default_gen == RADEON_PCIE_GEN3))
+                        return RADEON_PCIE_GEN3;
+                else if ((sys_mask & DRM_PCIE_SPEED_50) && (default_gen == RADEON_PCIE_GEN2))
+                        return RADEON_PCIE_GEN2;
+                else
+                        return RADEON_PCIE_GEN1;
+        }
+        return RADEON_PCIE_GEN1;
+}