RE: [RFC PATCH 2/2] ASoC: da732x: simplify code

From: Adam Thomson
Date: Thu Apr 15 2021 - 12:00:55 EST


On 26 March 2021 22:16, Pierre-Louis Bossart wrote:

> cppcheck reports a false positive:
>
> sound/soc/codecs/da732x.c:1161:25: warning: Either the condition
> 'indiv<0' is redundant or there is division by zero at line
> 1161. [zerodivcond]
> fref = (da732x->sysclk / indiv);
> ^
> sound/soc/codecs/da732x.c:1158:12: note: Assuming that condition
> 'indiv<0' is not redundant
> if (indiv < 0)
> ^
> sound/soc/codecs/da732x.c:1161:25: note: Division by zero
> fref = (da732x->sysclk / indiv);
> ^
>
> The code is awfully convoluted/confusing and can be simplified with a
> single variable and the BIT macro.
>
> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
> ---

Apologies for the delay in getting to this. The change looks fine to me,
although this part was EOL some time back, and I find it hard to believe anyone
out there has a board with this on. Wondering if it would make sense to remove
the driver permanently?

For the change at hand though:

Reviewed-by: Adam Thomson <Adam.Thomson.Opensource@xxxxxxxxxxx>

> sound/soc/codecs/da732x.c | 17 ++++++-----------
> sound/soc/codecs/da732x.h | 12 ++++--------
> 2 files changed, 10 insertions(+), 19 deletions(-)
>
> diff --git a/sound/soc/codecs/da732x.c b/sound/soc/codecs/da732x.c
> index d43ee7159ae0..42d6a3fc3af5 100644
> --- a/sound/soc/codecs/da732x.c
> +++ b/sound/soc/codecs/da732x.c
> @@ -168,30 +168,25 @@ static const struct reg_default da732x_reg_cache[] = {
> static inline int da732x_get_input_div(struct snd_soc_component *component,
> int sysclk)
> {
> int val;
> - int ret;
>
> if (sysclk < DA732X_MCLK_10MHZ) {
> - val = DA732X_MCLK_RET_0_10MHZ;
> - ret = DA732X_MCLK_VAL_0_10MHZ;
> + val = DA732X_MCLK_VAL_0_10MHZ;
> } else if ((sysclk >= DA732X_MCLK_10MHZ) &&
> (sysclk < DA732X_MCLK_20MHZ)) {
> - val = DA732X_MCLK_RET_10_20MHZ;
> - ret = DA732X_MCLK_VAL_10_20MHZ;
> + val = DA732X_MCLK_VAL_10_20MHZ;
> } else if ((sysclk >= DA732X_MCLK_20MHZ) &&
> (sysclk < DA732X_MCLK_40MHZ)) {
> - val = DA732X_MCLK_RET_20_40MHZ;
> - ret = DA732X_MCLK_VAL_20_40MHZ;
> + val = DA732X_MCLK_VAL_20_40MHZ;
> } else if ((sysclk >= DA732X_MCLK_40MHZ) &&
> (sysclk <= DA732X_MCLK_54MHZ)) {
> - val = DA732X_MCLK_RET_40_54MHZ;
> - ret = DA732X_MCLK_VAL_40_54MHZ;
> + val = DA732X_MCLK_VAL_40_54MHZ;
> } else {
> return -EINVAL;
> }
>
> snd_soc_component_write(component, DA732X_REG_PLL_CTRL, val);
>
> - return ret;
> + return val;
> }
>
> static void da732x_set_charge_pump(struct snd_soc_component *component,
> int state)
> @@ -1158,7 +1153,7 @@ static int da732x_set_dai_pll(struct
> snd_soc_component *component, int pll_id,
> if (indiv < 0)
> return indiv;
>
> - fref = (da732x->sysclk / indiv);
> + fref = da732x->sysclk / BIT(indiv);
> div_hi = freq_out / fref;
> frac_div = (u64)(freq_out % fref) * 8192ULL;
> do_div(frac_div, fref);
> diff --git a/sound/soc/codecs/da732x.h b/sound/soc/codecs/da732x.h
> index c5af17ee1516..c2f784c3f359 100644
> --- a/sound/soc/codecs/da732x.h
> +++ b/sound/soc/codecs/da732x.h
> @@ -48,14 +48,10 @@
> #define DA732X_MCLK_20MHZ 20000000
> #define DA732X_MCLK_40MHZ 40000000
> #define DA732X_MCLK_54MHZ 54000000
> -#define DA732X_MCLK_RET_0_10MHZ 0
> -#define DA732X_MCLK_VAL_0_10MHZ 1
> -#define DA732X_MCLK_RET_10_20MHZ 1
> -#define DA732X_MCLK_VAL_10_20MHZ 2
> -#define DA732X_MCLK_RET_20_40MHZ 2
> -#define DA732X_MCLK_VAL_20_40MHZ 4
> -#define DA732X_MCLK_RET_40_54MHZ 3
> -#define DA732X_MCLK_VAL_40_54MHZ 8
> +#define DA732X_MCLK_VAL_0_10MHZ 0
> +#define DA732X_MCLK_VAL_10_20MHZ 1
> +#define DA732X_MCLK_VAL_20_40MHZ 2
> +#define DA732X_MCLK_VAL_40_54MHZ 3
> #define DA732X_DAI_ID1 0
> #define DA732X_DAI_ID2 1
> #define DA732X_SRCCLK_PLL 0
> --
> 2.25.1