clk: imx: pllv4: Fix SPLL2 MULT range

[ Upstream commit 3f0cdb9 ]

The SPLL2 on iMX8ULP is different with other frac PLLs, it can
support VCO from 650Mhz to 1Ghz. According to RM, the MULT is
using a range from 27 to 54, not some fixed values. If using
current PLL implementation, some clock rate can't be supported.

Fix the issue by adding new type for the SPLL2 and use MULT range
to replace MULT table

Fixes: 5f0601c ("clk: imx: Update the pllv4 to support imx8ulp")
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Jacky Bai <ping.bai@nxp.com>
Signed-off-by: Ye Li <ye.li@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Abel Vesa <abel.vesa@linaro.org>
Link: https://lore.kernel.org/r/20230625123340.4067536-1-peng.fan@oss.nxp.com
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/clk/imx/clk-pllv4.c

@@ -44,11 +44,15 @@ struct clk_pllv4 {
 	u32		cfg_offset;
 	u32		num_offset;
 	u32		denom_offset;
+	bool		use_mult_range;
 };
 
 /* Valid PLL MULT Table */
 static const int pllv4_mult_table[] = {33, 27, 22, 20, 17, 16};
 
+/* Valid PLL MULT range, (max, min) */
+static const int pllv4_mult_range[] = {54, 27};
+
 #define to_clk_pllv4(__hw) container_of(__hw, struct clk_pllv4, hw)
 
 #define LOCK_TIMEOUT_US		USEC_PER_MSEC
@@ -94,17 +98,30 @@ static unsigned long clk_pllv4_recalc_rate(struct clk_hw *hw,
 static long clk_pllv4_round_rate(struct clk_hw *hw, unsigned long rate,
 				 unsigned long *prate)
 {
+	struct clk_pllv4 *pll = to_clk_pllv4(hw);
 	unsigned long parent_rate = *prate;
 	unsigned long round_rate, i;
 	u32 mfn, mfd = DEFAULT_MFD;
 	bool found = false;
 	u64 temp64;
-
-	for (i = 0; i < ARRAY_SIZE(pllv4_mult_table); i++) {
-		round_rate = parent_rate * pllv4_mult_table[i];
-		if (rate >= round_rate) {
+	u32 mult;
+
+	if (pll->use_mult_range) {
+		temp64 = (u64)rate;
+		do_div(temp64, parent_rate);
+		mult = temp64;
+		if (mult >= pllv4_mult_range[1] &&
+		    mult <= pllv4_mult_range[0]) {
+			round_rate = parent_rate * mult;
 			found = true;
-			break;
+		}
+	} else {
+		for (i = 0; i < ARRAY_SIZE(pllv4_mult_table); i++) {
+			round_rate = parent_rate * pllv4_mult_table[i];
+			if (rate >= round_rate) {
+				found = true;
+				break;
+			}
 		}
 	}
 
@@ -138,14 +155,20 @@ static long clk_pllv4_round_rate(struct clk_hw *hw, unsigned long rate,
 	return round_rate + (u32)temp64;
 }
 
-static bool clk_pllv4_is_valid_mult(unsigned int mult)
+static bool clk_pllv4_is_valid_mult(struct clk_pllv4 *pll, unsigned int mult)
 {
 	int i;
 
 	/* check if mult is in valid MULT table */
-	for (i = 0; i < ARRAY_SIZE(pllv4_mult_table); i++) {
-		if (pllv4_mult_table[i] == mult)
+	if (pll->use_mult_range) {
+		if (mult >= pllv4_mult_range[1] &&
+		    mult <= pllv4_mult_range[0])
 			return true;
+	} else {
+		for (i = 0; i < ARRAY_SIZE(pllv4_mult_table); i++) {
+			if (pllv4_mult_table[i] == mult)
+				return true;
+		}
 	}
 
 	return false;
@@ -160,7 +183,7 @@ static int clk_pllv4_set_rate(struct clk_hw *hw, unsigned long rate,
 
 	mult = rate / parent_rate;
 
-	if (!clk_pllv4_is_valid_mult(mult))
+	if (!clk_pllv4_is_valid_mult(pll, mult))
 		return -EINVAL;
 
 	if (parent_rate <= MAX_MFD)
@@ -227,10 +250,13 @@ struct clk_hw *imx_clk_hw_pllv4(enum imx_pllv4_type type, const char *name,
 
 	pll->base = base;
 
-	if (type == IMX_PLLV4_IMX8ULP) {
+	if (type == IMX_PLLV4_IMX8ULP ||
+	    type == IMX_PLLV4_IMX8ULP_1GHZ) {
 		pll->cfg_offset = IMX8ULP_PLL_CFG_OFFSET;
 		pll->num_offset = IMX8ULP_PLL_NUM_OFFSET;
 		pll->denom_offset = IMX8ULP_PLL_DENOM_OFFSET;
+		if (type == IMX_PLLV4_IMX8ULP_1GHZ)
+			pll->use_mult_range = true;
 	} else {
 		pll->cfg_offset = PLL_CFG_OFFSET;
 		pll->num_offset = PLL_NUM_OFFSET;

drivers/clk/imx/clk.h

@@ -46,6 +46,7 @@ enum imx_pll14xx_type {
 enum imx_pllv4_type {
 	IMX_PLLV4_IMX7ULP,
 	IMX_PLLV4_IMX8ULP,
+	IMX_PLLV4_IMX8ULP_1GHZ,
 };
 
 enum imx_pfdv2_type {