Re: [PATCH] ASoC: fsl_asrc: Add an option to select internal ratio mode

[Fabio Estevam <festevam@gmail.com>]

Hi Shengjiu,

On Mon, Jun 29, 2020 at 11:10 AM Shengjiu Wang <shengjiu.wang@nxp.com> wrote:

> +/**

"/**" notation may confuse 'make htmldocs". Since this is a single
line comment you could do:

/* Select proper clock source for internal ratio mode */


> + * Select proper clock source for internal ratio mode
> + */
> +static int fsl_asrc_select_clk(struct fsl_asrc_priv *asrc_priv,
> +                              struct fsl_asrc_pair *pair,
> +                              int in_rate,
> +                              int out_rate)
> +{
> +       struct fsl_asrc_pair_priv *pair_priv = pair->private;
> +       struct asrc_config *config = pair_priv->config;
> +       int rate[2], select_clk[2]; /* Array size 2 means IN and OUT */
> +       int clk_rate, clk_index;
> +       int i = 0, j = 0;
> +       bool clk_sel[2];
> +
> +       rate[0] = in_rate;
> +       rate[1] = out_rate;
> +
> +       /* Select proper clock source for internal ratio mode */
> +       for (j = 0; j < 2; j++) {
> +               for (i = 0; i < ASRC_CLK_MAP_LEN; i++) {
> +                       clk_index = asrc_priv->clk_map[j][i];
> +                       clk_rate = clk_get_rate(asrc_priv->asrck_clk[clk_index]);
> +                       if (clk_rate != 0 && (clk_rate / rate[j]) <= 1024 &&
> +                           (clk_rate % rate[j]) == 0)
> +                               break;
> +               }
> +
> +               if (i == ASRC_CLK_MAP_LEN) {
> +                       select_clk[j] = OUTCLK_ASRCK1_CLK;
> +                       clk_sel[j] = false;
> +               } else {
> +                       select_clk[j] = i;
> +                       clk_sel[j] = true;
> +               }
> +       }
> +
> +       /* Switch to ideal ratio mode if there is no proper clock source */
> +       if (!clk_sel[IN] || !clk_sel[OUT])
> +               select_clk[IN] = INCLK_NONE;
> +
> +       config->inclk = select_clk[IN];
> +       config->outclk = select_clk[OUT];
> +
> +       return 0;

This new function always returns 0. Should it be converted to 'void'
type instead?

> +       ret = fsl_asrc_select_clk(asrc_priv, pair,
> +                                 config.input_sample_rate,
> +                                 config.output_sample_rate);
> +       if (ret) {
> +               dev_err(dai->dev, "fail to select clock\n");

fsl_asrc_select_clk() does not return error, so you could skip the
error checking.