[PATCH] ASoC: fsl-asoc-card: Get "extal" clock rate by clk_get_rate

[PATCH] ASoC: fsl-asoc-card: Get "extal" clock rate by clk_get_rate

[Shengjiu Wang]

On some platform(.e.g. i.MX8QM MEK), the "extal" clock is different
with the mclk of codec, then the clock rate is also different.
So it is better to get clock rate of "extal" rate by clk_get_rate,
don't reuse the clock rate of mclk.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
---
 sound/soc/fsl/fsl-asoc-card.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/sound/soc/fsl/fsl-asoc-card.c b/sound/soc/fsl/fsl-asoc-card.c
index 52adedc03245..2c92a5efad61 100644
--- a/sound/soc/fsl/fsl-asoc-card.c
+++ b/sound/soc/fsl/fsl-asoc-card.c
@@ -696,6 +696,13 @@ static int fsl_asoc_card_probe(struct platform_device *pdev)
 			goto asrc_fail;
 		}
 	} else if (of_node_name_eq(cpu_np, "esai")) {
+		struct clk *esai_clk = clk_get(&cpu_pdev->dev, "extal");
+
+		if (!IS_ERR(esai_clk)) {
+			priv->cpu_priv.sysclk_freq[TX] = clk_get_rate(esai_clk);
+			priv->cpu_priv.sysclk_freq[RX] = clk_get_rate(esai_clk);
+			clk_put(esai_clk);
+		}
 		priv->cpu_priv.sysclk_id[1] = ESAI_HCKT_EXTAL;
 		priv->cpu_priv.sysclk_id[0] = ESAI_HCKR_EXTAL;
 	} else if (of_node_name_eq(cpu_np, "sai")) {
-- 
2.27.0

Re: [PATCH] ASoC: fsl-asoc-card: Get "extal" clock rate by clk_get_rate

[Mark Brown]

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On Thu, Aug 06, 2020 at 03:39:45PM +0800, Shengjiu Wang wrote:

>  	} else if (of_node_name_eq(cpu_np, "esai")) {
> +		struct clk *esai_clk = clk_get(&cpu_pdev->dev, "extal");
> +
> +		if (!IS_ERR(esai_clk)) {
> +			priv->cpu_priv.sysclk_freq[TX] = clk_get_rate(esai_clk);
> +			priv->cpu_priv.sysclk_freq[RX] = clk_get_rate(esai_clk);
> +			clk_put(esai_clk);
> +		}

This should handle probe deferral.  Also if this clock is in use
shouldn't we be enabling it?  It looks like it's intended to be a
crystal so it's probably forced on all the time but sometimes there's
power control for crystals, or perhaps someone might do something
unusual with the hardware.

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Re: [PATCH] ASoC: fsl-asoc-card: Get "extal" clock rate by clk_get_rate

[Shengjiu Wang]

On Thu, Aug 6, 2020 at 8:39 PM Mark Brown <broonie@kernel.org> wrote:
>
> On Thu, Aug 06, 2020 at 03:39:45PM +0800, Shengjiu Wang wrote:
>
> >       } else if (of_node_name_eq(cpu_np, "esai")) {
> > +             struct clk *esai_clk = clk_get(&cpu_pdev->dev, "extal");
> > +
> > +             if (!IS_ERR(esai_clk)) {
> > +                     priv->cpu_priv.sysclk_freq[TX] = clk_get_rate(esai_clk);
> > +                     priv->cpu_priv.sysclk_freq[RX] = clk_get_rate(esai_clk);
> > +                     clk_put(esai_clk);
> > +             }
>
> This should handle probe deferral.  Also if this clock is in use
> shouldn't we be enabling it?  It looks like it's intended to be a
> crystal so it's probably forced on all the time but sometimes there's
> power control for crystals, or perhaps someone might do something
> unusual with the hardware.

Ok, will add handler for probe deferral.

This clock is not a crystal, "extal" clock is for cpu dai, it is from
soc internal PLL. which is enabled by cpu dai, here is just to
get the clock rate.

best regards
wang shengjiu