[PATCH 1/3] ASoC: simple-card-utils: Fix device module clock

From: Michael Walle
Date: Tue Mar 09 2021 - 09:42:55 EST


Hi,

> If "clocks = <&xxx>" is specified from the CPU or Codec component
> device node, the clock is not getting enabled. Thus audio playback
> or capture fails.
>
> Fix this by populating "simple_dai->clk" field when clocks property
> is specified from device node as well. Also tidy up by re-organising
> conditional statements of parsing logic.
>
> Fixes: bb6fc620c2ed ("ASoC: simple-card-utils: add asoc_simple_card_parse_clk()")
> Cc: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>
> Signed-off-by: Sameer Pujar <spujar@xxxxxxxxxx>

This actually breaks sound on my board
(arch/arm64/boot/dts/freescale/fsl-ls1028a-kontron-sl28-var3-ads2.dts).
The codec on this board (wm8904) has a fixed clock input (only distinct
frequencies are supported) and uses the FLL of the codec to generate the
desired sample rate.

It seems that after this patch the clock rate of the codecs clock (rather
than the FLL) is tried to be changed. Which fails, because it doesn't
support arbitrary frequencies.

-michael

> ---
> sound/soc/generic/simple-card-utils.c | 13 ++++++-------
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/sound/soc/generic/simple-card-utils.c b/sound/soc/generic/simple-card-utils.c
> index bc0b62e..0754d70 100644
> --- a/sound/soc/generic/simple-card-utils.c
> +++ b/sound/soc/generic/simple-card-utils.c
> @@ -173,16 +173,15 @@ int asoc_simple_parse_clk(struct device *dev,
> * or device's module clock.
> */
> clk = devm_get_clk_from_child(dev, node, NULL);
> - if (!IS_ERR(clk)) {
> - simple_dai->sysclk = clk_get_rate(clk);
> + if (IS_ERR(clk))
> + clk = devm_get_clk_from_child(dev, dlc->of_node, NULL);
>
> + if (!IS_ERR(clk)) {
> simple_dai->clk = clk;
> - } else if (!of_property_read_u32(node, "system-clock-frequency", &val)) {
> + simple_dai->sysclk = clk_get_rate(clk);
> + } else if (!of_property_read_u32(node, "system-clock-frequency",
> + &val)) {
> simple_dai->sysclk = val;
> - } else {
> - clk = devm_get_clk_from_child(dev, dlc->of_node, NULL);
> - if (!IS_ERR(clk))
> - simple_dai->sysclk = clk_get_rate(clk);
> }
>
> if (of_property_read_bool(node, "system-clock-direction-out"))
> --
> 2.7.4
>
>