clk: samsung: clk-pll: Add support for pll_531x

pll531x PLL is used in Exynos Auto v920 SoC for shared pll.
pll531x: Integer/fractional PLL with mid frequency FVCO (800 to 3120 MHz)

PLL531x
FOUT = (MDIV x FIN)/(PDIV x 2^SDIV) for integer PLL
FOUT = (MDIV + F/2^32-F[31]) x FIN/(PDIV x 2^SDIV) for fractional PLL
Signed-off-by: Sunyeal Hong <sunyeal.hong@samsung.com>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Link: https://lore.kernel.org/r/20240821232652.1077701-4-sunyeal.hong@samsung.comSigned-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

drivers/clk/samsung/clk-pll.c

@@ -1272,6 +1272,47 @@ static const struct clk_ops samsung_pll2650xx_clk_min_ops = {
 	.recalc_rate = samsung_pll2650xx_recalc_rate,
 };
 
+/*
+ * PLL531X Clock Type
+ */
+/* Maximum lock time can be 500 * PDIV cycles */
+#define PLL531X_LOCK_FACTOR		(500)
+#define PLL531X_MDIV_MASK		(0x3FF)
+#define PLL531X_PDIV_MASK		(0x3F)
+#define PLL531X_SDIV_MASK		(0x7)
+#define PLL531X_FDIV_MASK		(0xFFFFFFFF)
+#define PLL531X_MDIV_SHIFT		(16)
+#define PLL531X_PDIV_SHIFT		(8)
+#define PLL531X_SDIV_SHIFT		(0)
+
+static unsigned long samsung_pll531x_recalc_rate(struct clk_hw *hw,
+						 unsigned long parent_rate)
+{
+	struct samsung_clk_pll *pll = to_clk_pll(hw);
+	u32 pdiv, sdiv, fdiv, pll_con0, pll_con8;
+	u64 mdiv, fout = parent_rate;
+
+	pll_con0 = readl_relaxed(pll->con_reg);
+	pll_con8 = readl_relaxed(pll->con_reg + 20);
+	mdiv = (pll_con0 >> PLL531X_MDIV_SHIFT) & PLL531X_MDIV_MASK;
+	pdiv = (pll_con0 >> PLL531X_PDIV_SHIFT) & PLL531X_PDIV_MASK;
+	sdiv = (pll_con0 >> PLL531X_SDIV_SHIFT) & PLL531X_SDIV_MASK;
+	fdiv = (pll_con8 & PLL531X_FDIV_MASK);
+
+	if (fdiv >> 31)
+		mdiv--;
+
+	fout *= (mdiv << 24) + (fdiv >> 8);
+	do_div(fout, (pdiv << sdiv));
+	fout >>= 24;
+
+	return (unsigned long)fout;
+}
+
+static const struct clk_ops samsung_pll531x_clk_ops = {
+	.recalc_rate = samsung_pll531x_recalc_rate,
+};
+
 static void __init _samsung_clk_register_pll(struct samsung_clk_provider *ctx,
 				const struct samsung_pll_clock *pll_clk)
 {
@@ -1406,6 +1447,9 @@ static void __init _samsung_clk_register_pll(struct samsung_clk_provider *ctx,
 		else
 			init.ops = &samsung_pll2650xx_clk_ops;
 		break;
+	case pll_531x:
+		init.ops = &samsung_pll531x_clk_ops;
+		break;
 	default:
 		pr_warn("%s: Unknown pll type for pll clk %s\n",
 			__func__, pll_clk->name);

drivers/clk/samsung/clk-pll.h

@@ -42,6 +42,7 @@ enum samsung_pll_type {
 	pll_0516x,
 	pll_0517x,
 	pll_0518x,
+	pll_531x,
 };
 
 #define PLL_RATE(_fin, _m, _p, _s, _k, _ks) \