ASoC: tlv320aic32x4: Fix the divide by zero

The value of register(NDAC,MDAC,NADC,MADC,BCLKN) maybe zero lead to
divide by zero in clk_aic32x4_div_recalc_rate().And the rate should be
divide by 128 if the value was zero in this function according to the
datasheet.

Add the macro AIC32X4_DIV_MAX to present the 128 and return 0 if failing
to read the value of register.

Signed-off-by: Guiting Shen <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

sound/soc/codecs/tlv320aic32x4-clk.c

···
 	u8 divisor;
 
 	divisor = DIV_ROUND_UP(parent_rate, rate);
-	if (divisor > 128)
+	if (divisor > AIC32X4_DIV_MAX)
 		return -EINVAL;
 
 	return regmap_update_bits(div->regmap, div->reg,
···
 	unsigned long divisor;
 
 	divisor = DIV_ROUND_UP(req->best_parent_rate, req->rate);
-	if (divisor > 128)
+	if (divisor > AIC32X4_DIV_MAX)
 		return -EINVAL;
 
 	req->rate = DIV_ROUND_UP(req->best_parent_rate, divisor);
···
 						unsigned long parent_rate)
 {
 	struct clk_aic32x4 *div = to_clk_aic32x4(hw);
-
 	unsigned int val;
+	int err;
 
-	regmap_read(div->regmap, div->reg, &val);
+	err = regmap_read(div->regmap, div->reg, &val);
+	if (err)
+		return 0;
 
-	return DIV_ROUND_UP(parent_rate, val & AIC32X4_DIV_MASK);
+	val &= AIC32X4_DIV_MASK;
+	if (!val)
+		val = AIC32X4_DIV_MAX;
+
+	return DIV_ROUND_UP(parent_rate, val);
 }
 
 static const struct clk_ops aic32x4_div_ops = {

sound/soc/codecs/tlv320aic32x4.h

···
 #define AIC32X4_REFPOWERUP_120MS	0x07
 
 /* Common mask and enable for all of the dividers */
-#define AIC32X4_DIVEN           BIT(7)
-#define AIC32X4_DIV_MASK        GENMASK(6, 0)
+#define AIC32X4_DIVEN			BIT(7)
+#define AIC32X4_DIV_MASK		GENMASK(6, 0)
+#define AIC32X4_DIV_MAX			128
 
 /* Clock Limits */
 #define AIC32X4_MAX_DOSR_FREQ		6200000