Re: [PATCH v7 6/6] ASoC: cs42l43: Add support for the cs42l43

From: Charles Keepax <ckeepax@opensource.cirrus.com>
To: <andy.shevchenko@gmail.com>
Cc: <broonie@kernel.org>, <lee@kernel.org>, <robh+dt@kernel.org>,
	<krzysztof.kozlowski+dt@linaro.org>, <conor+dt@kernel.org>,
	<linus.walleij@linaro.org>, <vkoul@kernel.org>,
	<lgirdwood@gmail.com>, <yung-chuan.liao@linux.intel.com>,
	<sanyog.r.kale@intel.com>, <pierre-louis.bossart@linux.intel.com>,
	<alsa-devel@alsa-project.org>, <patches@opensource.cirrus.com>,
	<devicetree@vger.kernel.org>, <linux-gpio@vger.kernel.org>,
	<linux-spi@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v7 6/6] ASoC: cs42l43: Add support for the cs42l43
Date: Fri, 19 Jan 2024 16:59:17 +0000	[thread overview]
Message-ID: <20240119165917.GC16899@ediswmail.ad.cirrus.com> (raw)
In-Reply-To: <Zali4qxdegY7H6eY@surfacebook.localdomain>

On Thu, Jan 18, 2024 at 07:41:54PM +0200, andy.shevchenko@gmail.com wrote:
> Fri, Aug 04, 2023 at 11:46:02AM +0100, Charles Keepax kirjoitti:
> > +static const unsigned int cs42l43_accdet_us[] = {
> > +	20, 100, 1000, 10000, 50000, 75000, 100000, 200000
> 
> + comma.
> 
> > +};
> > +
> > +static const unsigned int cs42l43_accdet_db_ms[] = {
> > +	0, 125, 250, 500, 750, 1000, 1250, 1500
> 
> Ditto.
> 

Can do.

> > +		device_property_read_u32_array(cs42l43->dev, "cirrus,buttons-ohms",
> > +					       priv->buttons, ret);
> 
> Strictly speaking this might fail, better to check the error code again.
> 

Yeah should probably add an error check there.

> > +	int timeout_ms = ((2 * priv->detect_us) / 1000) + 200;
> 
> USEC_PER_MSEC ?
> 

Can do.

> > +	BUILD_BUG_ON(ARRAY_SIZE(cs42l43_jack_override_modes) !=
> > +		     ARRAY_SIZE(cs42l43_jack_text) - 1);
> 
> Use static_assert() instead.
> 

I am happy either way, but for my own education what is the
reason to prefer static_assert here, is it just to be able to use
== rather than !=? Or is there in general a preference to use
static_assert, there is no obvious since BUILD_BUG_ON is being
deprecated?

> > +static void cs42l43_mask_to_slots(struct cs42l43_codec *priv, unsigned int mask, int *slots)
> > +{
> > +	int i;
> > +
> > +	for (i = 0; i < CS42L43_ASP_MAX_CHANNELS; ++i) {
> > +		int slot = ffs(mask) - 1;
> > +
> > +		if (slot < 0)
> > +			return;
> > +
> > +		slots[i] = slot;
> > +
> > +		mask &= ~(1 << slot);
> > +	}
> 
> for_each_set_bit() ?
> 
> > +	if (mask)
> > +		dev_warn(priv->dev, "Too many channels in TDM mask\n");
> > +}
> 

Can do.

> > +static int cs42l43_decim_get(struct snd_kcontrol *kcontrol,
> > +			     struct snd_ctl_elem_value *ucontrol)
> > +{
> > +	struct snd_soc_component *component = snd_soc_kcontrol_component(kcontrol);
> > +	struct cs42l43_codec *priv = snd_soc_component_get_drvdata(component);
> > +	int ret;
> > +
> > +	ret = cs42l43_shutter_get(priv, CS42L43_STATUS_MIC_SHUTTER_MUTE_SHIFT);
> > +	if (ret < 0)
> > +		return ret;
> > +	else if (!ret)
> 
> Reundant 'else'
> 
> > +		ucontrol->value.integer.value[0] = ret;
> > +	else
> > +		ret = cs42l43_dapm_get_volsw(kcontrol, ucontrol);
> 
> and why not positive check?
> 
> > +	return ret;
> 
> Or even simply as
> 
> 	if (ret > 0)
> 		ret = cs42l43_dapm_get_volsw(kcontrol, ucontrol);
> 	else if (ret == 0)
> 		ucontrol->value.integer.value[0] = ret;
> 
> 	return ret;

Yeah will update, that is definitely neater.

> > +	while (freq > cs42l43_pll_configs[ARRAY_SIZE(cs42l43_pll_configs) - 1].freq) {
> > +		div++;
> > +		freq /= 2;
> > +	}
> 
> fls() / fls_long()?

Apologies but I might need a little bit more of a pointer here.
We need to scale freq down to under 3.072MHz and I am struggling
a little to see how to do that with fls.

> > +	// Don't use devm as we need to get against the MFD device
> 
> This is weird...
> 
> > +	priv->mclk = clk_get_optional(cs42l43->dev, "mclk");
> > +	if (IS_ERR(priv->mclk)) {
> > +		dev_err_probe(priv->dev, PTR_ERR(priv->mclk), "Failed to get mclk\n");
> > +		goto err_pm;
> > +	}
> > +
> > +	ret = devm_snd_soc_register_component(priv->dev, &cs42l43_component_drv,
> > +					      cs42l43_dais, ARRAY_SIZE(cs42l43_dais));
> > +	if (ret) {
> > +		dev_err_probe(priv->dev, ret, "Failed to register component\n");
> > +		goto err_clk;
> > +	}
> > +
> > +	pm_runtime_mark_last_busy(priv->dev);
> > +	pm_runtime_put_autosuspend(priv->dev);
> > +
> > +	return 0;
> > +
> > +err_clk:
> > +	clk_put(priv->mclk);
> > +err_pm:
> > +	pm_runtime_put_sync(priv->dev);
> > +
> > +	return ret;
> > +}
> > +
> > +static int cs42l43_codec_remove(struct platform_device *pdev)
> > +{
> > +	struct cs42l43_codec *priv = platform_get_drvdata(pdev);
> > +
> > +	clk_put(priv->mclk);
> 
> You have clocks put before anything else, and your remove order is broken now.
> 
> To fix this (in case you may not used devm_clk_get() call), you should drop
> devm calls all way after the clk_get(). Do we have
> snd_soc_register_component()? If yes, use it to fix.
> 
> I believe you never tested rmmod/modprobe in a loop.
> 

Hmm... will need to think this through a little bit, so might take
a little longer on this one. But I guess this only becomes a problem
if you attempt to remove the driver whilst you are currently playing
audio, and I would expect the card tear down would stop the clock
running before we get here.

> > +static const struct dev_pm_ops cs42l43_codec_pm_ops = {
> > +	SET_RUNTIME_PM_OPS(NULL, cs42l43_codec_runtime_resume, NULL)
> > +};
> 
> Why not new PM macros?
> 

Already been updated in another patch.

> > +		.pm	= &cs42l43_codec_pm_ops,
> 
> pm_sleep_ptr()?
> 

Can do.

> > +#include <linux/clk.h>
> > +#include <linux/device.h>
> > +#include <linux/regmap.h>
> > +#include <linux/soundwire/sdw.h>
> > +#include <linux/types.h>
> > +#include <sound/cs42l43.h>
> > +#include <sound/pcm.h>
> > +#include <sound/soc-jack.h>
> 
> This block is messed up. Some headers can be replaced by forward declarations,
> some are missing... Please, follow IWYU principle.
> 
> > +#ifndef CS42L43_ASOC_INT_H
> > +#define CS42L43_ASOC_INT_H
> 
> Why not guarding other inclusions? It makes build slower!
> 

Will shuffle these headers around as well.

Thanks,
Charles