On Mon, Mar 05, 2018 at 01:48:16PM +0100, Mylène Josserand wrote:

> --- /dev/null
> +++ b/sound/soc/codecs/pcm1789-i2c.c
> @@ -0,0 +1,76 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * PCM1789 ASoC I2C driver
> + *
> + * Copyright (c) Bootlin 2018
> + *
> + * Mylène Josserand <mylene.josserand@bootlin.com>
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License

Please don't mix C and C++ style comments in a single comment like this
- it looks unintentional.  Just use the same style for the whole thing.
You also don't need to include all the boilerplate with the SPDX header.

> +static bool pcm1789_accessible_reg(struct device *dev, unsigned int reg)
> +{
> +	return reg >= PCM1789_MUTE_CONTROL && reg <= PCM1789_DAC_VOL_RIGHT;
> +}
> +
> +static bool pcm1789_writeable_reg(struct device *dev, unsigned int reg)
> +{
> +	return pcm1789_accessible_reg(dev, reg);
> +}

> +static void pcm1789_work_queue(struct work_struct *work)
> +{
> +	struct pcm1789_private *priv = container_of(work,
> +						    struct pcm1789_private,
> +						    work);
> +
> +	/* Perform a software reset to remove codec from desynchronized state */
> +	if (regmap_update_bits(priv->regmap, PCM1789_MUTE_CONTROL,
> +			       0x3 << PCM1789_MUTE_SRET, 0) < 0)
> +		dev_err(priv->dev, "Error while setting SRET");
> +}

A reset sounds like we'd also need to resync the register map,
presumably this is something else?  The comment could be clearer.