linux-kernel - Re: [PATCH v5 04/10] regulator: Do pure DT regulator lookup in of_regulator_bulk_get

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Message-ID: <ZsdC8wkgsdsMJuAL@smile.fi.intel.com>
Date: Thu, 22 Aug 2024 16:53:55 +0300
From: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To: Chen-Yu Tsai <wenst@...omium.org>
Cc: Rob Herring <robh@...nel.org>, Saravana Kannan <saravanak@...gle.com>,
	Matthias Brugger <matthias.bgg@...il.com>,
	AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>,
	Wolfram Sang <wsa@...nel.org>, Benson Leung <bleung@...omium.org>,
	Tzung-Bi Shih <tzungbi@...nel.org>, Mark Brown <broonie@...nel.org>,
	Liam Girdwood <lgirdwood@...il.com>,
	chrome-platform@...ts.linux.dev, devicetree@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	linux-mediatek@...ts.infradead.org, linux-kernel@...r.kernel.org,
	Douglas Anderson <dianders@...omium.org>,
	Johan Hovold <johan@...nel.org>, Jiri Kosina <jikos@...nel.org>,
	linux-i2c@...r.kernel.org
Subject: Re: [PATCH v5 04/10] regulator: Do pure DT regulator lookup in
 of_regulator_bulk_get_all()

On Thu, Aug 22, 2024 at 05:19:57PM +0800, Chen-Yu Tsai wrote:
> The to-be-introduced I2C component prober needs to enable regulator
> supplies (and toggle GPIO pins) for the various components it intends
> to probe. To support this, a new "pure DT lookup" method for getting
> regulator supplies is needed, since the device normally requesting
> the supply won't get created until after the component is probed to
> be available.
> 
> Convert the existing of_regulator_bulk_get_all() for this purpose.
> This function has no in-tree users, as the original patch [1] that
> used it was never landed. This patch changes the function ABI, but
> it is straightforward to convert users.
> 
> The underlying code that supports the existing regulator_get*()
> functions has been reworked in previous patches to support this
> specific case. An internal OF-specific version of regulator_get(),
> of_regulator_get_optional(), is added for this.

> [1] https://lore.kernel.org/all/20231220203537.83479-2-jernej.skrabec@gmail.com/

Make it Link tag

Link: https://lore.kernel.org/all/20231220203537.83479-2-jernej.skrabec@gmail.com/ [1]
Signed-off-by: Chen-Yu Tsai <wenst@...omium.org>

...

>  	/* first do a dt based lookup */
>  	if (dev && dev->of_node) {

	if (dev_of_node())


> -		r = of_regulator_dev_lookup(dev, supply);
> +		r = of_regulator_dev_lookup(dev, dev->of_node, supply);

	dev_of_node()

>  		if (!IS_ERR(r))
>  			return r;
>  		if (PTR_ERR(r) == -EPROBE_DEFER)

...

>  /**
>   * of_get_regulator - get a regulator device node based on supply name
> - * @dev: Device pointer for the consumer (of regulator) device
> + * @dev: Device pointer for dev_printk messages

dev_printk()

> + * @node: Device node pointer for supply property lookup
>   * @supply: regulator supply name
>   *
>   * Extract the regulator device node corresponding to the supply name.
>   * returns the device node corresponding to the regulator if found, else
>   * returns NULL.
>   */

...

>  /** of_regulator_dev_lookup - lookup a regulator device with device tree only
> - * @dev: Device pointer for regulator supply lookup.
> + * @dev: Device pointer for dev_printk messages.

Ditto.

> + * @node: Device node pointer for regulator supply lookup.
>   * @supply: Supply name or regulator ID.
>   *
>   * If successful, returns a struct regulator_dev that corresponds to the name
> @@ -636,13 +639,13 @@ static struct regulator_dev *of_find_regulator_by_node(struct device_node *np)
>   * -ENODEV if lookup fails permanently, -EPROBE_DEFER if lookup could succeed
>   * in the future.
>   */

...

> +/**
> + * of_regulator_get_optional - get optional regulator via device tree lookup
> + * @dev: device used for dev_printk messages

Ditto.

> + * @node: device node for regulator "consumer"
> + * @id: Supply name
> + *
> + * Returns a struct regulator corresponding to the regulator producer,
> + * or IS_ERR() condition containing errno.
> + *
> + * This is intended for use by consumers that want to get a regulator
> + * supply directly from a device node, and can and want to deal with
> + * absence of such supplies. This will _not_ consider supply aliases.
> + * See regulator_dev_lookup().

Fix kernel-doc warning.

> + */

-- 
With Best Regards,
Andy Shevchenko