On Thu, Apr 09, 2020 at 02:58:30PM -0500, Pierre-Louis Bossart wrote:
> The SCLK is resumed by the codec driver. In case the rate specified in
> hw_params does not match the current configuration, disable, set the
> new rate and restart the clock.
>
> There is no operation on hw_free, the codec suspend routine will
> disable/deprepare the clock.
>
> Note that we don't change the DAI configuration when the DAC+ PRO is
> detected. All changes for the codec master mode are handled in the
> topology file (DAI configuration change and scheduling change)
...
> + err = snd_interval_ratnum(hw_param_interval(params,
> + SNDRV_PCM_HW_PARAM_RATE),
> + 1, &rats_no_pll, &num, &den);
> + if (err >= 0 && den) {
Perhaps usual pattern, i.e.
if (err < 0 || !den)
return 0;
(so, above seems optional configuration)
params...;
return 0;
> + params->rate_num = num;
> + params->rate_den = den;
> + }
> +
> + return 0;
...
> +static int aif1_hw_params(struct snd_pcm_substream *substream,
> + struct snd_pcm_hw_params *params)
> +{
> + struct snd_soc_pcm_runtime *rtd = substream->private_data;
> + struct sof_card_private *ctx = snd_soc_card_get_drvdata(rtd->card);
> + struct device *dev = rtd->card->dev;
> + int current_rate;
> + int sclk_rate;
> + int channels;
> + int width;
> + int rate;
> + int ret = 0;
> +
> + if (ctx->is_dac_pro) {
if (!...)
return 0;
...and drop the redundant ret assignment above.
> + rate = params_rate(params);
> + channels = params_channels(params);
> + width = snd_pcm_format_physical_width(params_format(params));
> +
> + if (rate % 24000)
> + sclk_rate = 22579200;
> + else
> + sclk_rate = 24576000;
> +
> + current_rate = clk_get_rate(ctx->sclk);
> + if (current_rate != sclk_rate) {
> + /*
> + * The sclk clock is started and stopped by the codec
> + * resume/suspend functions. If the rate isn't correct,
> + * stop, set the new rate and restart the clock
> + */
> +
> + dev_dbg(dev, "reconfiguring SCLK to rate %d\n",
> + sclk_rate);
> +
> + clk_disable_unprepare(ctx->sclk);
> +
> + ret = clk_set_rate(ctx->sclk, sclk_rate);
> + if (ret) {
> + dev_err(dev, "Could not set SCLK rate %d\n",
> + sclk_rate);
> + return ret;
> + }
> +
> + ret = clk_prepare_enable(ctx->sclk);
> + if (ret) {
> + dev_err(dev, "Failed to enable SCLK: %d\n",
> + ret);
> + return ret;
> + }
> + }
> +
> + ret = aif1_update_rate_den(substream, params);
> + if (ret) {
> + dev_err(dev, "Failed to update rate denominator: %d\n", ret);
> + return ret;
> + }
Do you still need below steps when current_rate == sclk_rate?
> + ret = snd_soc_dai_set_bclk_ratio(rtd->codec_dai,
> + channels * width);
> + if (ret) {
> + dev_err(dev, "Failed to set bclk ratio : %d\n", ret);
> + return ret;
> + }
> + }
> +
> + return ret;
> +}
--
With Best Regards,
Andy Shevchenko
