Re: [PATCH 13/14] ASoC: Intel: bytcr_wm5102: Add machine driver for BYT/WM5102

[Charles Keepax]

On Sun, Dec 27, 2020 at 10:12:31PM +0100, Hans de Goede wrote:
> From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
> 
> Add a new ASoc Machine driver for Intel Baytrail platforms with a
> Wolfson Microelectronics WM5102 codec.
> 
> This is based on a past contributions [1] from Paulo Sergio Travaglia
> <pstglia@xxxxxxxxx> based on the Levono kernel [2] combined with
> insights in things like the speaker GPIO from the android-x86 android
> port for the Lenovo Yoga Tablet 2 1051F/L [3].
> 
> [1] https://patchwork.kernel.org/project/alsa-devel/patch/593313f5.3636c80a.50e05.47e9@xxxxxxxxxxxxx/
> [2] https://github.com/lenovo-yt2-dev/android_kernel_lenovo_baytrail/blob/cm-12.1/sound/soc/intel/board/byt_bl_wm5102.c
> [3] https://github.com/Kitsune2222/Android_Yoga_Tablet_2-1051F_Kernel
> 
> The original machine driver from the Android ports was a crude modified
> copy of bytcr_rt5640.c adjusted to work with the WM5102 codec.
> This version has been extensively reworked to:
> 
> 1. Remove all rt5640 related quirk handling. to the best of my knowledge
> this setup is only used on the Lenovo Yoga Tablet 2 series (8, 10 and 13
> inch models) which all use the same setup. So there is no need to deal
> with all the variations with which we need to deal on rt5640 boards.
> 
> 2. Rework clock handling, properly turn off the FLL and the platform-clock
> when they are no longer necessary and don't reconfigure the FLL
> unnecessarily when it is already running. This fixes a number of:
> "Timed out waiting for lock" warnings being logged.
> 
> 3. Add the GPIO controlled Speaker-VDD regulator as a DAPM_SUPPLY
> 
> This only adds the machine driver and ACPI hooks, the BYT-CR detection
> quirk which these devices need will be added in a separate patch.
> 
> Co-authored-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> ---

Just a couple really minor comments.

> +static int byt_wm5102_prepare_and_enable_pll1(struct snd_soc_dai *codec_dai, int rate)
> +{
> +	struct snd_soc_component *codec_component = codec_dai->component;
> +	int sr_mult = ((rate % 4000) == 0) ?
> +		(WM5102_MAX_SYSCLK_4K / rate) :
> +		(WM5102_MAX_SYSCLK_11025 / rate);
> +	int ret;
> +
> +	/* Reset FLL1 */
> +	snd_soc_dai_set_pll(codec_dai, WM5102_FLL1_REFCLK, ARIZONA_FLL_SRC_NONE, 0, 0);
> +	snd_soc_dai_set_pll(codec_dai, WM5102_FLL1, ARIZONA_FLL_SRC_NONE, 0, 0);
> +
> +	/* Configure the FLL1 PLL before selecting it */
> +	ret = snd_soc_dai_set_pll(codec_dai, WM5102_FLL1, ARIZONA_CLK_SRC_MCLK1,
> +				  MCLK_FREQ, rate * sr_mult);
> +	if (ret) {
> +		dev_err(codec_component->dev, "Error setting PLL: %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = snd_soc_component_set_sysclk(codec_component, ARIZONA_CLK_SYSCLK,
> +					   ARIZONA_CLK_SRC_FLL1, rate * sr_mult,
> +					   SND_SOC_CLOCK_IN);
> +	if (ret) {
> +		dev_err(codec_component->dev, "Error setting ASYNCCLK: %d\n", ret);

Error message should say SYSCLK not ASYNCCLK.

> +		return ret;
> +	}
> +
> +	ret = snd_soc_component_set_sysclk(codec_component, ARIZONA_CLK_OPCLK, 0,
> +					   rate * sr_mult, SND_SOC_CLOCK_OUT);
> +	if (ret) {
> +		dev_err(codec_component->dev, "Error setting OPCLK: %d\n", ret);
> +		return ret;
> +	}

OPCLK is a clock that can be outputted on the CODECs GPIOs. Is
that being used to clock some external component? If so it should
be added to the DAPM graph, if not you might as well remove this
call.

> +
> +	ret = snd_soc_dai_set_sysclk(codec_dai, ARIZONA_CLK_SYSCLK,
> +				     rate * 512, SND_SOC_CLOCK_IN);
> +	if (ret) {
> +		dev_err(codec_component->dev, "Error setting clock: %d\n", ret);
> +		return ret;
> +	}
> +

The rate you set here doesn't actually matter, on wm5102 this
just links the DAI to a specific clock domain and as they all
default to SYSCLK you can omit this call if you want. Although no
harm is caused by leaving it in.

Thanks,
Charles