linux-kernel - Re: [RESEND PATCH v3 3/3] regulator: mcp16502: add regulator driver for MCP16502

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Message-ID: <20181211164706.GL6686@sirena.org.uk>
Date:   Tue, 11 Dec 2018 16:47:06 +0000
From:   Mark Brown <broonie@...nel.org>
To:     Andrei.Stefanescu@...rochip.com
Cc:     robh+dt@...nel.org, lgirdwood@...il.com, mark.rutland@....com,
        gregkh@...uxfoundation.org, Cristian.Birsan@...rochip.com,
        Nicolas.Ferre@...rochip.com, Claudiu.Beznea@...rochip.com,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        devicetree@...r.kernel.org
Subject: Re: [RESEND PATCH v3 3/3] regulator: mcp16502: add regulator driver
 for MCP16502

On Tue, Dec 11, 2018 at 10:09:15AM +0000, Andrei.Stefanescu@...rochip.com wrote:
> This patch adds a regulator driver for the MCP16502 PMIC.
> This drivers supports basic operations through the
> regulator interface such as:

Overall this looks really good, just a couple of comments:

> +++ b/drivers/regulator/mcp16502.c
> @@ -0,0 +1,555 @@
> +/* SPDX-License-Identifier: GPL-2.0
> + *
> + * MCP16502 PMIC driver

SPDX headers need to be C++ comments - please make the entire comment
block a C++ one so it looks more intentional.

> +#ifdef CONFIG_SUSPEND
> +static int mcp16502_suspend(struct device *dev)
> +{
> +	struct i2c_client *client = to_i2c_client(dev);
> +	struct mcp16502 *mcp = i2c_get_clientdata(client);
> +
> +	mcp16502_gpio_set_mode(mcp, MCP16502_OPMODE_LPM);
> +
> +	return 0;
> +}

This puts the device into low power mode when the suspend function gets
called but this might not be safe - devices using the regulator may not
be suspended yet so could still need full regulation.  Normally a GPIO
triggered transition like this would be being done by hardware as part
of the process of suspending the SoC.  Is there some reason to do this
manually?

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