drm/i915: Remove the fragile array index -> link rate mapping

Rather than try to maintain some magic relationship between the link
rates and the index into the wrpll params array let's just store
the link rate in the array itself. Much less fragile.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190207173230.22368-13-ville.syrjala@linux.intel.comReviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>

drivers/gpu/drm/i915/intel_dpll_mgr.c

@@ -2417,47 +2417,69 @@ static const struct intel_dpll_mgr cnl_pll_mgr = {
 	.dump_hw_state = cnl_dump_hw_state,
 };
 
+struct icl_combo_pll_params {
+	int clock;
+	struct skl_wrpll_params wrpll;
+};
+
 /*
  * 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[] = {
+static const struct icl_combo_pll_params icl_dp_combo_pll_24MHz_values[] = {
+	{ 540000,
 	  { .dco_integer = 0x151, .dco_fraction = 0x4000,		/* [0]: 5.4 */
-	  .pdiv = 0x2 /* 3 */, .kdiv = 1, .qdiv_mode = 0, .qdiv_ratio = 0},
+	    .pdiv = 0x2 /* 3 */, .kdiv = 1, .qdiv_mode = 0, .qdiv_ratio = 0, }, },
+	{ 270000,
 	  { .dco_integer = 0x151, .dco_fraction = 0x4000,		/* [1]: 2.7 */
-	  .pdiv = 0x2 /* 3 */, .kdiv = 2, .qdiv_mode = 0, .qdiv_ratio = 0},
+	    .pdiv = 0x2 /* 3 */, .kdiv = 2, .qdiv_mode = 0, .qdiv_ratio = 0, }, },
+	{ 162000,
 	  { .dco_integer = 0x151, .dco_fraction = 0x4000,		/* [2]: 1.62 */
-	  .pdiv = 0x4 /* 5 */, .kdiv = 2, .qdiv_mode = 0, .qdiv_ratio = 0},
+	    .pdiv = 0x4 /* 5 */, .kdiv = 2, .qdiv_mode = 0, .qdiv_ratio = 0, }, },
+	{ 324000,
 	  { .dco_integer = 0x151, .dco_fraction = 0x4000,		/* [3]: 3.24 */
-	  .pdiv = 0x4 /* 5 */, .kdiv = 1, .qdiv_mode = 0, .qdiv_ratio = 0},
+	    .pdiv = 0x4 /* 5 */, .kdiv = 1, .qdiv_mode = 0, .qdiv_ratio = 0, }, },
+	{ 216000,
 	  { .dco_integer = 0x168, .dco_fraction = 0x0000,		/* [4]: 2.16 */
-	  .pdiv = 0x1 /* 2 */, .kdiv = 2, .qdiv_mode = 1, .qdiv_ratio = 2},
+	    .pdiv = 0x1 /* 2 */, .kdiv = 2, .qdiv_mode = 1, .qdiv_ratio = 2, }, },
+	{ 432000,
 	  { .dco_integer = 0x168, .dco_fraction = 0x0000,		/* [5]: 4.32 */
-	  .pdiv = 0x1 /* 2 */, .kdiv = 2, .qdiv_mode = 0, .qdiv_ratio = 0},
+	    .pdiv = 0x1 /* 2 */, .kdiv = 2, .qdiv_mode = 0, .qdiv_ratio = 0, }, },
+	{ 648000,
 	  { .dco_integer = 0x195, .dco_fraction = 0x0000,		/* [6]: 6.48 */
-	  .pdiv = 0x2 /* 3 */, .kdiv = 1, .qdiv_mode = 0, .qdiv_ratio = 0},
+	    .pdiv = 0x2 /* 3 */, .kdiv = 1, .qdiv_mode = 0, .qdiv_ratio = 0, }, },
+	{ 810000,
 	  { .dco_integer = 0x151, .dco_fraction = 0x4000,		/* [7]: 8.1 */
-	  .pdiv = 0x1 /* 2 */, .kdiv = 1, .qdiv_mode = 0, .qdiv_ratio = 0},
+	    .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[] = {
+static const struct icl_combo_pll_params icl_dp_combo_pll_19_2MHz_values[] = {
+	{ 540000,
 	  { .dco_integer = 0x1A5, .dco_fraction = 0x7000,		/* [0]: 5.4 */
-	  .pdiv = 0x2 /* 3 */, .kdiv = 1, .qdiv_mode = 0, .qdiv_ratio = 0},
+	    .pdiv = 0x2 /* 3 */, .kdiv = 1, .qdiv_mode = 0, .qdiv_ratio = 0, }, },
+	{ 270000,
 	  { .dco_integer = 0x1A5, .dco_fraction = 0x7000,		/* [1]: 2.7 */
-	  .pdiv = 0x2 /* 3 */, .kdiv = 2, .qdiv_mode = 0, .qdiv_ratio = 0},
+	    .pdiv = 0x2 /* 3 */, .kdiv = 2, .qdiv_mode = 0, .qdiv_ratio = 0, }, },
+	{ 162000,
 	  { .dco_integer = 0x1A5, .dco_fraction = 0x7000,		/* [2]: 1.62 */
-	  .pdiv = 0x4 /* 5 */, .kdiv = 2, .qdiv_mode = 0, .qdiv_ratio = 0},
+	    .pdiv = 0x4 /* 5 */, .kdiv = 2, .qdiv_mode = 0, .qdiv_ratio = 0, }, },
+	{ 324000,
 	  { .dco_integer = 0x1A5, .dco_fraction = 0x7000,		/* [3]: 3.24 */
-	  .pdiv = 0x4 /* 5 */, .kdiv = 1, .qdiv_mode = 0, .qdiv_ratio = 0},
+	    .pdiv = 0x4 /* 5 */, .kdiv = 1, .qdiv_mode = 0, .qdiv_ratio = 0, }, },
+	{ 216000,
 	  { .dco_integer = 0x1C2, .dco_fraction = 0x0000,		/* [4]: 2.16 */
-	  .pdiv = 0x1 /* 2 */, .kdiv = 2, .qdiv_mode = 1, .qdiv_ratio = 2},
+	    .pdiv = 0x1 /* 2 */, .kdiv = 2, .qdiv_mode = 1, .qdiv_ratio = 2, }, },
+	{ 432000,
 	  { .dco_integer = 0x1C2, .dco_fraction = 0x0000,		/* [5]: 4.32 */
-	  .pdiv = 0x1 /* 2 */, .kdiv = 2, .qdiv_mode = 0, .qdiv_ratio = 0},
+	    .pdiv = 0x1 /* 2 */, .kdiv = 2, .qdiv_mode = 0, .qdiv_ratio = 0, }, },
+	{ 648000,
 	  { .dco_integer = 0x1FA, .dco_fraction = 0x2000,		/* [6]: 6.48 */
-	  .pdiv = 0x2 /* 3 */, .kdiv = 1, .qdiv_mode = 0, .qdiv_ratio = 0},
+	    .pdiv = 0x2 /* 3 */, .kdiv = 1, .qdiv_mode = 0, .qdiv_ratio = 0, }, },
+	{ 810000,
 	  { .dco_integer = 0x1A5, .dco_fraction = 0x7000,		/* [7]: 8.1 */
-	  .pdiv = 0x1 /* 2 */, .kdiv = 1, .qdiv_mode = 0, .qdiv_ratio = 0},
+	    .pdiv = 0x1 /* 2 */, .kdiv = 1, .qdiv_mode = 0, .qdiv_ratio = 0, }, },
 };
 
 static const struct skl_wrpll_params icl_tbt_pll_24MHz_values = {
@@ -2474,44 +2496,22 @@ static bool icl_calc_dp_combo_pll(struct intel_crtc_state *crtc_state,
 				  struct skl_wrpll_params *pll_params)
 {
 	struct drm_i915_private *dev_priv = to_i915(crtc_state->base.crtc->dev);
-	const struct skl_wrpll_params *params;
-	int clock = crtc_state->port_clock;
-
-	params = dev_priv->cdclk.hw.ref == 24000 ?
+	const struct icl_combo_pll_params *params =
+		dev_priv->cdclk.hw.ref == 24000 ?
 		icl_dp_combo_pll_24MHz_values :
 		icl_dp_combo_pll_19_2MHz_values;
+	int clock = crtc_state->port_clock;
+	int i;
 
-	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;
+	for (i = 0; i < ARRAY_SIZE(icl_dp_combo_pll_24MHz_values); i++) {
+		if (clock == params[i].clock) {
+			*pll_params = params[i].wrpll;
+			return true;
+		}
 	}
 
-	return true;
+	MISSING_CASE(clock);
+	return false;
 }
 
 static bool icl_calc_tbt_pll(struct intel_crtc_state *crtc_state,