drm/i915/tgl: Add support for dkl pll write

Add a new function to write to dkl phy pll registers. As per the
bspec all the registers are read modify write.
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Vandita Kulkarni <vandita.kulkarni@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190924210040.142075-2-jose.souza@intel.com

drivers/gpu/drm/i915/display/intel_dpll_mgr.c

@@ -3295,7 +3295,70 @@ static void icl_mg_pll_write(struct drm_i915_private *dev_priv,
 static void dkl_pll_write(struct drm_i915_private *dev_priv,
 			  struct intel_shared_dpll *pll)
 {
-	/* TODO */
+	struct intel_dpll_hw_state *hw_state = &pll->state.hw_state;
+	enum tc_port tc_port = icl_pll_id_to_tc_port(pll->info->id);
+	u32 val;
+
+	/*
+	 * All registers programmed here have the same HIP_INDEX_REG even
+	 * though on different building block
+	 */
+	I915_WRITE(HIP_INDEX_REG(tc_port), HIP_INDEX_VAL(tc_port, 0x2));
+
+	/* All the registers are RMW */
+	val = I915_READ(DKL_REFCLKIN_CTL(tc_port));
+	val &= ~MG_REFCLKIN_CTL_OD_2_MUX_MASK;
+	val |= hw_state->mg_refclkin_ctl;
+	I915_WRITE(DKL_REFCLKIN_CTL(tc_port), val);
+
+	val = I915_READ(DKL_CLKTOP2_CORECLKCTL1(tc_port));
+	val &= ~MG_CLKTOP2_CORECLKCTL1_A_DIVRATIO_MASK;
+	val |= hw_state->mg_clktop2_coreclkctl1;
+	I915_WRITE(DKL_CLKTOP2_CORECLKCTL1(tc_port), val);
+
+	val = I915_READ(DKL_CLKTOP2_HSCLKCTL(tc_port));
+	val &= ~(MG_CLKTOP2_HSCLKCTL_TLINEDRV_CLKSEL_MASK |
+		 MG_CLKTOP2_HSCLKCTL_CORE_INPUTSEL_MASK |
+		 MG_CLKTOP2_HSCLKCTL_HSDIV_RATIO_MASK |
+		 MG_CLKTOP2_HSCLKCTL_DSDIV_RATIO_MASK);
+	val |= hw_state->mg_clktop2_hsclkctl;
+	I915_WRITE(DKL_CLKTOP2_HSCLKCTL(tc_port), val);
+
+	val = I915_READ(DKL_PLL_DIV0(tc_port));
+	val &= ~(DKL_PLL_DIV0_INTEG_COEFF_MASK |
+		 DKL_PLL_DIV0_PROP_COEFF_MASK |
+		 DKL_PLL_DIV0_FBPREDIV_MASK |
+		 DKL_PLL_DIV0_FBDIV_INT_MASK);
+	val |= hw_state->mg_pll_div0;
+	I915_WRITE(DKL_PLL_DIV0(tc_port), val);
+
+	val = I915_READ(DKL_PLL_DIV1(tc_port));
+	val &= ~(DKL_PLL_DIV1_IREF_TRIM_MASK |
+		 DKL_PLL_DIV1_TDC_TARGET_CNT_MASK);
+	val |= hw_state->mg_pll_div1;
+	I915_WRITE(DKL_PLL_DIV1(tc_port), val);
+
+	val = I915_READ(DKL_PLL_SSC(tc_port));
+	val &= ~(DKL_PLL_SSC_IREF_NDIV_RATIO_MASK |
+		 DKL_PLL_SSC_STEP_LEN_MASK |
+		 DKL_PLL_SSC_STEP_NUM_MASK |
+		 DKL_PLL_SSC_EN);
+	val |= hw_state->mg_pll_ssc;
+	I915_WRITE(DKL_PLL_SSC(tc_port), val);
+
+	val = I915_READ(DKL_PLL_BIAS(tc_port));
+	val &= ~(DKL_PLL_BIAS_FRAC_EN_H |
+		 DKL_PLL_BIAS_FBDIV_FRAC_MASK);
+	val |= hw_state->mg_pll_bias;
+	I915_WRITE(DKL_PLL_BIAS(tc_port), val);
+
+	val = I915_READ(DKL_PLL_TDC_COLDST_BIAS(tc_port));
+	val &= ~(DKL_PLL_TDC_SSC_STEP_SIZE_MASK |
+		 DKL_PLL_TDC_FEED_FWD_GAIN_MASK);
+	val |= hw_state->mg_pll_tdc_coldst_bias;
+	I915_WRITE(DKL_PLL_TDC_COLDST_BIAS(tc_port), val);
+
+	POSTING_READ(DKL_PLL_TDC_COLDST_BIAS(tc_port));
 }
 
 static void icl_pll_power_enable(struct drm_i915_private *dev_priv,