lkml.org 
[lkml]   [2024]   [May]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCHv4 7/9] ASoC: fsl-asoc-card: add DT clock "cpu_sysclk" with generic codec
From: "Mark Brown" <broonie@kernel.org>
Sent: Thursday, 16 May, 2024 14:13:19
> On Wed, May 15, 2024 at 03:54:09PM +0200, Elinor Montmasson wrote:
>
>> Add an optional DT clock "cpu_sysclk" to get the CPU DAI system-clock
>> frequency when using the generic codec.
>> It is set for both Tx and Rx.
>> The way the frequency value is used is up to the CPU DAI driver
>> implementation.
>
>> + struct clk *cpu_sysclk = clk_get(&pdev->dev, "cpu_sysclk");
>> + if (!IS_ERR(cpu_sysclk)) {
>> + priv->cpu_priv.sysclk_freq[TX] = clk_get_rate(cpu_sysclk);
>> + priv->cpu_priv.sysclk_freq[RX] = priv->cpu_priv.sysclk_freq[TX];
>> + clk_put(cpu_sysclk);
>> + }
>
> I don't really understand the goal here - this is just reading whatever
> frequency happens to be set in the hardware when the driver starts up
> which if nothing else seems rather fragile?

The driver allow to set the sysclk frequency
of the CPU DAI through `priv->cpu_priv.sysclk_freq` when calling
`fsl_asoc_card_hw_params()`.
Currently it is hard-coded per use-case in the driver.

My reasoning was that with a generic codec/compatible, there might
be use-cases needing to use this parameter, so I exposed it here via DT.

Is it a bad idea to expose this parameter ? This is not a requirement for the
driver to work, most of the current compatibles do not use this parameter.
It is currently used only for `fsl,imx-audio-cs42888`.
In that case I can remove this commit.

Best regards,
Elinor Montmasson

\
 
 \ /
  Last update: 2024-05-27 18:30    [W:0.338 / U:0.016 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site