On some platforms, for example i.MX93, there is only one
audio PLL source, so some sample rate can't be supported.
If the PLL source is used for 8kHz series rates, then 11kHz
series rates can't be supported.

So add constraints according to the frequency of available
clock sources, then alsa-lib will help to convert the
unsupported rate for the driver.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
---
 sound/soc/fsl/fsl_micfil.c | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/sound/soc/fsl/fsl_micfil.c b/sound/soc/fsl/fsl_micfil.c
index 4e65966d54fc..619ee7a5b867 100644
--- a/sound/soc/fsl/fsl_micfil.c
+++ b/sound/soc/fsl/fsl_micfil.c
@@ -28,6 +28,13 @@
 
 #define MICFIL_OSR_DEFAULT	16
 
+#define MICFIL_NUM_RATES	7
+#define MICFIL_CLK_SRC_NUM	3
+/* clock source ids */
+#define MICFIL_AUDIO_PLL1	0
+#define MICFIL_AUDIO_PLL2	1
+#define MICFIL_CLK_EXT3		2
+
 enum quality {
 	QUALITY_HIGH,
 	QUALITY_MEDIUM,
@@ -45,9 +52,12 @@ struct fsl_micfil {
 	struct clk *mclk;
 	struct clk *pll8k_clk;
 	struct clk *pll11k_clk;
+	struct clk *clk_src[MICFIL_CLK_SRC_NUM];
 	struct snd_dmaengine_dai_dma_data dma_params_rx;
 	struct sdma_peripheral_config sdmacfg;
 	struct snd_soc_card *card;
+	struct snd_pcm_hw_constraint_list constraint_rates;
+	unsigned int constraint_rates_list[MICFIL_NUM_RATES];
 	unsigned int dataline;
 	char name[32];
 	int irq[MICFIL_IRQ_LINES];
@@ -450,12 +460,34 @@ static int fsl_micfil_startup(struct snd_pcm_substream *substream,
 			      struct snd_soc_dai *dai)
 {
 	struct fsl_micfil *micfil = snd_soc_dai_get_drvdata(dai);
+	unsigned int rates[MICFIL_NUM_RATES] = {8000, 11025, 16000, 22050, 32000, 44100, 48000};
+	int i, j, k = 0;
+	u64 clk_rate;
 
 	if (!micfil) {
 		dev_err(dai->dev, "micfil dai priv_data not set\n");
 		return -EINVAL;
 	}
 
+	micfil->constraint_rates.list = micfil->constraint_rates_list;
+	micfil->constraint_rates.count = 0;
+
+	for (j = 0; j < MICFIL_NUM_RATES; j++) {
+		for (i = 0; i < MICFIL_CLK_SRC_NUM; i++) {
+			clk_rate = clk_get_rate(micfil->clk_src[i]);
+			if (clk_rate != 0 && do_div(clk_rate, rates[j]) == 0) {
+				micfil->constraint_rates_list[k++] = rates[j];
+				micfil->constraint_rates.count++;
+				break;
+			}
+		}
+	}
+
+	if (micfil->constraint_rates.count > 0)
+		snd_pcm_hw_constraint_list(substream->runtime, 0,
+					   SNDRV_PCM_HW_PARAM_RATE,
+					   &micfil->constraint_rates);
+
 	return 0;
 }
 
@@ -1160,6 +1192,12 @@ static int fsl_micfil_probe(struct platform_device *pdev)
 	fsl_asoc_get_pll_clocks(&pdev->dev, &micfil->pll8k_clk,
 				&micfil->pll11k_clk);
 
+	micfil->clk_src[MICFIL_AUDIO_PLL1] = micfil->pll8k_clk;
+	micfil->clk_src[MICFIL_AUDIO_PLL2] = micfil->pll11k_clk;
+	micfil->clk_src[MICFIL_CLK_EXT3] = devm_clk_get(&pdev->dev, "clkext3");
+	if (IS_ERR(micfil->clk_src[MICFIL_CLK_EXT3]))
+		micfil->clk_src[MICFIL_CLK_EXT3] = NULL;
+
 	/* init regmap */
 	regs = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
 	if (IS_ERR(regs))
-- 
2.34.1

On Mon, 14 Oct 2024 13:38:33 +0800, Shengjiu Wang wrote:
> On some platforms, for example i.MX93, there is only one
> audio PLL source, so some sample rate can't be supported.
> If the PLL source is used for 8kHz series rates, then 11kHz
> series rates can't be supported.
> 
> So add constraints according to the frequency of available
> clock sources, then alsa-lib will help to convert the
> unsupported rate for the driver.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next

Thanks!

[1/1] ASoC: fsl_micfil: Add sample rate constraint
      commit: b9a8ecf81066e01e8a3de35517481bc5aa0439e5

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark