[PATCH] ASoC: tlv320aic32x4: Fix the divide by zero

From: Guiting Shen
Date: Wed Jul 12 2023 - 11:12:30 EST


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 <aarongt.shen@xxxxxxxxx>
---
sound/soc/codecs/tlv320aic32x4-clk.c | 16 +++++++++++-----
sound/soc/codecs/tlv320aic32x4.h | 5 +++--
2 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/sound/soc/codecs/tlv320aic32x4-clk.c b/sound/soc/codecs/tlv320aic32x4-clk.c
index c116e82f712d..5c0a76a4a106 100644
--- a/sound/soc/codecs/tlv320aic32x4-clk.c
+++ b/sound/soc/codecs/tlv320aic32x4-clk.c
@@ -321,7 +321,7 @@ static int clk_aic32x4_div_set_rate(struct clk_hw *hw, unsigned long rate,
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,
@@ -334,7 +334,7 @@ static int clk_aic32x4_div_determine_rate(struct clk_hw *hw,
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);
@@ -345,12 +345,18 @@ static unsigned long clk_aic32x4_div_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_aic32x4 *div = to_clk_aic32x4(hw);
-
unsigned int val;
+ int err;
+
+ err = regmap_read(div->regmap, div->reg, &val);
+ if (err)
+ return 0;

- regmap_read(div->regmap, div->reg, &val);
+ val &= AIC32X4_DIV_MASK;
+ if (!val)
+ val = AIC32X4_DIV_MAX;

- return DIV_ROUND_UP(parent_rate, val & AIC32X4_DIV_MASK);
+ return DIV_ROUND_UP(parent_rate, val);
}

static const struct clk_ops aic32x4_div_ops = {
diff --git a/sound/soc/codecs/tlv320aic32x4.h b/sound/soc/codecs/tlv320aic32x4.h
index 4de5bd9e8cc5..d6101ce73f80 100644
--- a/sound/soc/codecs/tlv320aic32x4.h
+++ b/sound/soc/codecs/tlv320aic32x4.h
@@ -223,8 +223,9 @@ int aic32x4_register_clocks(struct device *dev, const char *mclk_name);
#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
--
2.25.1