[PATCH 3/3] drm/i915/icl: use previous pll hw readout

[Lucas De Marchi]

By the time icl_ddi_clock_get() is called we've just got the hw state
from the pll registers. We don't need to read them again: we can rather
reuse what was cached in the dpll_hw_state.

Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
---
 drivers/gpu/drm/i915/intel_ddi.c | 33 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index fe52af9fa4aa..9ffbd48eda49 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -1372,26 +1372,23 @@ static int icl_calc_tbt_pll_link(struct drm_i915_private *dev_priv,
 	}
 }
 
+
 static int icl_calc_mg_pll_link(struct drm_i915_private *dev_priv,
-				enum port port)
+				struct intel_dpll_hw_state *state)
 {
-	enum tc_port tc_port = intel_port_to_tc(dev_priv, port);
-	u32 mg_pll_div0, mg_clktop_hsclkctl;
 	u32 m1, m2_int, m2_frac, div1, div2, refclk;
 	u64 tmp;
 
 	refclk = dev_priv->cdclk.hw.ref;
 
-	mg_pll_div0 = I915_READ(MG_PLL_DIV0(tc_port));
-	mg_clktop_hsclkctl = I915_READ(MG_CLKTOP2_HSCLKCTL(tc_port));
-
-	m1 = I915_READ(MG_PLL_DIV1(tc_port)) & MG_PLL_DIV1_FBPREDIV_MASK;
-	m2_int = mg_pll_div0 & MG_PLL_DIV0_FBDIV_INT_MASK;
-	m2_frac = (mg_pll_div0 & MG_PLL_DIV0_FRACNEN_H) ?
-		  (mg_pll_div0 & MG_PLL_DIV0_FBDIV_FRAC_MASK) >>
+	m1 = state->mg_pll_div1 & MG_PLL_DIV1_FBPREDIV_MASK;
+	m2_int = state->mg_pll_div0 & MG_PLL_DIV0_FBDIV_INT_MASK;
+	m2_frac = (state->mg_pll_div0 & MG_PLL_DIV0_FRACNEN_H) ?
+		  (state->mg_pll_div0 & MG_PLL_DIV0_FBDIV_FRAC_MASK) >>
 		  MG_PLL_DIV0_FBDIV_FRAC_SHIFT : 0;
 
-	switch (mg_clktop_hsclkctl & MG_CLKTOP2_HSCLKCTL_HSDIV_RATIO_MASK) {
+	switch (state->mg_clktop2_hsclkctl &
+		MG_CLKTOP2_HSCLKCTL_HSDIV_RATIO_MASK) {
 	case MG_CLKTOP2_HSCLKCTL_HSDIV_RATIO_2:
 		div1 = 2;
 		break;
@@ -1405,12 +1402,14 @@ static int icl_calc_mg_pll_link(struct drm_i915_private *dev_priv,
 		div1 = 7;
 		break;
 	default:
-		MISSING_CASE(mg_clktop_hsclkctl);
+		MISSING_CASE(state->mg_clktop2_hsclkctl);
 		return 0;
 	}
 
-	div2 = (mg_clktop_hsclkctl & MG_CLKTOP2_HSCLKCTL_DSDIV_RATIO_MASK) >>
+	div2 = (state->mg_clktop2_hsclkctl &
+		MG_CLKTOP2_HSCLKCTL_DSDIV_RATIO_MASK) >>
 		MG_CLKTOP2_HSCLKCTL_DSDIV_RATIO_SHIFT;
+
 	/* div2 value of 0 is same as 1 means no div */
 	if (div2 == 0)
 		div2 = 1;
@@ -1457,9 +1456,6 @@ static void icl_ddi_clock_get(struct intel_encoder *encoder,
 	struct intel_dpll_hw_state *state;
 	enum port port = encoder->port;
 	int link_clock = 0;
-	u32 pll_id;
-
-	pll_id = intel_get_shared_dpll_id(dev_priv, pipe_config->shared_dpll);
 
 	/* For DDI ports we always use a shared PLL. */
 	if (WARN_ON(!pipe_config->shared_dpll))
@@ -1470,10 +1466,13 @@ static void icl_ddi_clock_get(struct intel_encoder *encoder,
 	if (intel_port_is_combophy(dev_priv, port)) {
 		link_clock = cnl_calc_wrpll_link(dev_priv, state);
 	} else {
+		enum intel_dpll_id pll_id = intel_get_shared_dpll_id(dev_priv,
+				pipe_config->shared_dpll);
+
 		if (pll_id == DPLL_ID_ICL_TBTPLL)
 			link_clock = icl_calc_tbt_pll_link(dev_priv, port);
 		else
-			link_clock = icl_calc_mg_pll_link(dev_priv, port);
+			link_clock = icl_calc_mg_pll_link(dev_priv, state);
 	}
 
 end:
-- 
2.20.1