drm/i915/icl: Refactor get_ddi_pll using helper func

Use the existing port-to-id helper function, to refactor
hence making it scalable.
Signed-off-by: Vandita Kulkarni <vandita.kulkarni@intel.com>
Signed-off-by: Mahesh Kumar <mahesh1.kumar@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Madhav Chauhan <madhav.chauhan@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181003072203.12848-4-mahesh1.kumar@intel.com

drivers/gpu/drm/i915/intel_display.c

@@ -9280,16 +9280,10 @@ static void icelake_get_ddi_pll(struct drm_i915_private *dev_priv,
 			return;
 		break;
 	case PORT_C:
-		id = DPLL_ID_ICL_MGPLL1;
-		break;
 	case PORT_D:
-		id = DPLL_ID_ICL_MGPLL2;
-		break;
 	case PORT_E:
-		id = DPLL_ID_ICL_MGPLL3;
-		break;
 	case PORT_F:
-		id = DPLL_ID_ICL_MGPLL4;
+		id = icl_port_to_mg_pll_id(port);
 		break;
 	default:
 		MISSING_CASE(port);

drivers/gpu/drm/i915/intel_dpll_mgr.c

@@ -2621,7 +2621,7 @@ static enum port icl_mg_pll_id_to_port(enum intel_dpll_id id)
 	return id - DPLL_ID_ICL_MGPLL1 + PORT_C;
 }
 
-static enum intel_dpll_id icl_port_to_mg_pll_id(enum port port)
+enum intel_dpll_id icl_port_to_mg_pll_id(enum port port)
 {
 	return port - PORT_C + DPLL_ID_ICL_MGPLL1;
 }

drivers/gpu/drm/i915/intel_dpll_mgr.h

@@ -345,5 +345,6 @@ void intel_dpll_dump_hw_state(struct drm_i915_private *dev_priv,
 int icl_calc_dp_combo_pll_link(struct drm_i915_private *dev_priv,
 			       uint32_t pll_id);
 int cnl_hdmi_pll_ref_clock(struct drm_i915_private *dev_priv);
+enum intel_dpll_id icl_port_to_mg_pll_id(enum port port);
 
 #endif /* _INTEL_DPLL_MGR_H_ */