Re: [PATCH 2/4] ASoC: codecs: add wsa883x amplifier support - Pierre-Louis Bossart

From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
To: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>, broonie@kernel.org
Cc: alsa-devel@alsa-project.org, lgirdwood@gmail.com,
	linux-kernel@vger.kernel.org, tiwai@suse.com
Subject: Re: [PATCH 2/4] ASoC: codecs: add wsa883x amplifier support
Date: Wed, 29 Jun 2022 10:03:02 -0500	[thread overview]
Message-ID: <352fac7e-597c-84af-d33b-bdff0e2acdb6@linux.intel.com> (raw)
In-Reply-To: <20220629090644.67982-3-srinivas.kandagatla@linaro.org>

> +/* 4 ports */
> +static struct sdw_dpn_prop wsa_sink_dpn_prop[WSA883X_MAX_SWR_PORTS] = {
> +	{
> +		/* DAC */
> +		.num = 1,
> +		.type = SDW_DPN_SIMPLE,
> +		.min_ch = 1,
> +		.max_ch = 1,
> +		.simple_ch_prep_sm = true,
> +		.read_only_wordlength = true,
> +	}, {

nit-pick: it's unusual to see such opening brackets for structure
initialization, usually there are on a new line.

> +		/* COMP */
> +		.num = 2,
> +		.type = SDW_DPN_SIMPLE,
> +		.min_ch = 1,
> +		.max_ch = 1,
> +		.simple_ch_prep_sm = true,
> +		.read_only_wordlength = true,
> +	}, {
> +		/* BOOST */
> +		.num = 3,
> +		.type = SDW_DPN_SIMPLE,
> +		.min_ch = 1,
> +		.max_ch = 1,
> +		.simple_ch_prep_sm = true,
> +		.read_only_wordlength = true,
> +	}, {
> +		/* VISENSE */
> +		.num = 4,
> +		.type = SDW_DPN_SIMPLE,
> +		.min_ch = 1,
> +		.max_ch = 1,
> +		.simple_ch_prep_sm = true,
> +		.read_only_wordlength = true,
> +	}
> +};

> +static int wsa883x_update_status(struct sdw_slave *slave,
> +				 enum sdw_slave_status status)
> +{
> +	struct wsa883x_priv *wsa883x = dev_get_drvdata(&slave->dev);
> +
> +	if (status == SDW_SLAVE_ATTACHED && slave->dev_num > 0)

do you actually need to test if slave->dev_num is > 0?

if I look at drivers/soundwire/bus.c, update_status cannot really be
invoked with dev_num == 0.

> +		wsa883x_init(wsa883x);
> +
> +	return 0;
> +}
> +

> +static int __maybe_unused wsa883x_runtime_resume(struct device *dev)
> +{
> +	struct sdw_slave *slave = dev_to_sdw_dev(dev);
> +	struct regmap *regmap = dev_get_regmap(dev, NULL);
> +	struct wsa883x_priv *wsa883x = dev_get_drvdata(dev);
> +	int ret;
> +
> +	ret = regulator_enable(wsa883x->vdd);
> +	if (ret) {
> +		dev_err(dev, "Failed to enable vdd regulator (%d)\n", ret);
> +		return ret;
> +	}
> +
> +	gpiod_direction_output(wsa883x->sd_n, 1);
> +
> +	wait_for_completion_timeout(&slave->initialization_complete,
> +				    msecs_to_jiffies(WSA883X_PROBE_TIMEOUT));

check for success? You don't want to enable regmap sync below if the
device never successfully attached and initialized.

> +
> +	usleep_range(20000, 20010);
> +	regcache_cache_only(regmap, false);
> +	regcache_sync(regmap);
> +
> +	return 0;
> +}