drm/i915/icl: compute the combo PHY (DPLL) DP registers

Just use the hardcoded tables provided by our spec.

v2: Rebase.
v3: Clarify that 38.4 uses the 19.2 table (James).
Reviewed-by: James Ausmus <james.ausmus@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180328215803.13835-6-paulo.r.zanoni@intel.com

drivers/gpu/drm/i915/intel_dpll_mgr.c

@@ -2409,6 +2409,91 @@ static const struct intel_dpll_mgr cnl_pll_mgr = {
 	.dump_hw_state = cnl_dump_hw_state,
 };
 
+/*
+ * These values alrea already adjusted: they're the bits we write to the
+ * registers, not the logical values.
+ */
+static const struct skl_wrpll_params icl_dp_combo_pll_24MHz_values[] = {
+	{ .dco_integer = 0x151, .dco_fraction = 0x4000,		/* [0]: 5.4 */
+	  .pdiv = 0x2 /* 3 */, .kdiv = 1, .qdiv_mode = 0, .qdiv_ratio = 0},
+	{ .dco_integer = 0x151, .dco_fraction = 0x4000,		/* [1]: 2.7 */
+	  .pdiv = 0x2 /* 3 */, .kdiv = 2, .qdiv_mode = 0, .qdiv_ratio = 0},
+	{ .dco_integer = 0x151, .dco_fraction = 0x4000,		/* [2]: 1.62 */
+	  .pdiv = 0x4 /* 5 */, .kdiv = 2, .qdiv_mode = 0, .qdiv_ratio = 0},
+	{ .dco_integer = 0x151, .dco_fraction = 0x4000,		/* [3]: 3.24 */
+	  .pdiv = 0x4 /* 5 */, .kdiv = 1, .qdiv_mode = 0, .qdiv_ratio = 0},
+	{ .dco_integer = 0x168, .dco_fraction = 0x0000,		/* [4]: 2.16 */
+	  .pdiv = 0x1 /* 2 */, .kdiv = 2, .qdiv_mode = 1, .qdiv_ratio = 2},
+	{ .dco_integer = 0x168, .dco_fraction = 0x0000,		/* [5]: 4.32 */
+	  .pdiv = 0x1 /* 2 */, .kdiv = 2, .qdiv_mode = 0, .qdiv_ratio = 0},
+	{ .dco_integer = 0x195, .dco_fraction = 0x0000,		/* [6]: 6.48 */
+	  .pdiv = 0x2 /* 3 */, .kdiv = 1, .qdiv_mode = 0, .qdiv_ratio = 0},
+	{ .dco_integer = 0x151, .dco_fraction = 0x4000,		/* [7]: 8.1 */
+	  .pdiv = 0x1 /* 2 */, .kdiv = 1, .qdiv_mode = 0, .qdiv_ratio = 0},
+};
+
+/* Also used for 38.4 MHz values. */
+static const struct skl_wrpll_params icl_dp_combo_pll_19_2MHz_values[] = {
+	{ .dco_integer = 0x1A5, .dco_fraction = 0x7000,		/* [0]: 5.4 */
+	  .pdiv = 0x2 /* 3 */, .kdiv = 1, .qdiv_mode = 0, .qdiv_ratio = 0},
+	{ .dco_integer = 0x1A5, .dco_fraction = 0x7000,		/* [1]: 2.7 */
+	  .pdiv = 0x2 /* 3 */, .kdiv = 2, .qdiv_mode = 0, .qdiv_ratio = 0},
+	{ .dco_integer = 0x1A5, .dco_fraction = 0x7000,		/* [2]: 1.62 */
+	  .pdiv = 0x4 /* 5 */, .kdiv = 2, .qdiv_mode = 0, .qdiv_ratio = 0},
+	{ .dco_integer = 0x1A5, .dco_fraction = 0x7000,		/* [3]: 3.24 */
+	  .pdiv = 0x4 /* 5 */, .kdiv = 1, .qdiv_mode = 0, .qdiv_ratio = 0},
+	{ .dco_integer = 0x1C2, .dco_fraction = 0x0000,		/* [4]: 2.16 */
+	  .pdiv = 0x1 /* 2 */, .kdiv = 2, .qdiv_mode = 1, .qdiv_ratio = 2},
+	{ .dco_integer = 0x1C2, .dco_fraction = 0x0000,		/* [5]: 4.32 */
+	  .pdiv = 0x1 /* 2 */, .kdiv = 2, .qdiv_mode = 0, .qdiv_ratio = 0},
+	{ .dco_integer = 0x1FA, .dco_fraction = 0x2000,		/* [6]: 6.48 */
+	  .pdiv = 0x2 /* 3 */, .kdiv = 1, .qdiv_mode = 0, .qdiv_ratio = 0},
+	{ .dco_integer = 0x1A5, .dco_fraction = 0x7000,		/* [7]: 8.1 */
+	  .pdiv = 0x1 /* 2 */, .kdiv = 1, .qdiv_mode = 0, .qdiv_ratio = 0},
+};
+
+static bool icl_calc_dp_combo_pll(struct drm_i915_private *dev_priv, int clock,
+				  struct skl_wrpll_params *pll_params)
+{
+	const struct skl_wrpll_params *params;
+
+	params = dev_priv->cdclk.hw.ref == 24000 ?
+			icl_dp_combo_pll_24MHz_values :
+			icl_dp_combo_pll_19_2MHz_values;
+
+	switch (clock) {
+	case 540000:
+		*pll_params = params[0];
+		break;
+	case 270000:
+		*pll_params = params[1];
+		break;
+	case 162000:
+		*pll_params = params[2];
+		break;
+	case 324000:
+		*pll_params = params[3];
+		break;
+	case 216000:
+		*pll_params = params[4];
+		break;
+	case 432000:
+		*pll_params = params[5];
+		break;
+	case 648000:
+		*pll_params = params[6];
+		break;
+	case 810000:
+		*pll_params = params[7];
+		break;
+	default:
+		MISSING_CASE(clock);
+		return false;
+	}
+
+	return true;
+}
+
 static bool icl_calc_dpll_state(struct intel_crtc_state *crtc_state,
 				struct intel_encoder *encoder, int clock,
 				struct intel_dpll_hw_state *pll_state)
@@ -2421,7 +2506,7 @@ static bool icl_calc_dpll_state(struct intel_crtc_state *crtc_state,
 	if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_HDMI))
 		ret = cnl_ddi_calculate_wrpll(clock, dev_priv, &pll_params);
 	else
-		ret = false; /* TODO */
+		ret = icl_calc_dp_combo_pll(dev_priv, clock, &pll_params);
 
 	if (!ret)
 		return false;