Re: [PATCH 09/15] gpio: support ROHM BD71815 GPOs

On Mon, 2021-01-11 at 08:15 +0200, Matti Vaittinen wrote:

On Sat, 2021-01-09 at 01:45 +0100, Linus Walleij wrote:

quoted

On Fri, Jan 8, 2021 at 2:39 PM Matti Vaittinen
[off-list ref] wrote:

quoted

Support GPO(s) found from ROHM BD71815 power management IC. The
IC
has two
GPO pins but only one is properly documented in data-sheet. The
driver
exposes by default only the documented GPO. The second GPO is
connected to
E5 pin and is marked as GND in data-sheet. Control for this
undocumented
pin can be enabled using a special DT property.

This driver is derived from work by Peter Yang <
yanglsh@embest-tech.com>
although not so much of original is left.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com

quoted

// Snip

quoted

quoted

+       g->chip.parent = pdev->dev.parent;
+       g->chip.of_node = pdev->dev.parent->of_node;
+       g->regmap = dev_get_regmap(pdev->dev.parent, NULL);
+       g->dev = &pdev->dev;
+
+       ret = devm_gpiochip_add_data(&pdev->dev, &g->chip, g);
+       if (ret < 0) {
+               dev_err(&pdev->dev, "could not register gpiochip,
%d\n", ret);
+               return ret;
+       }

It's a bit confusing how you use pdev->dev.parent for some stuff
and &pdev->dev for some.

What about assinging

struct device *dev = pdev->dev.parent;

and use dev for all the calls, it looks like it'd work fine.

I wouldn't bind the lifetime of devm functions to the parent device.
I
am not sure if it would work - what happens we bind lifetime of XX to
parent device - and next call at probe fails (for example with
DEFERRED?) I _assume_ the XX bound to parent is not released?
(Please,
do correct me if I am wrong!)

/*
 * Bind devm lifetime to this platform device => use dev for devm.
 * also the prints should originate from this device.
 */
dev = &pdev->dev;
/* The device-tree and regmap come from MFD => use parent for that */
parent = dev->parent;

Maybe adding dev and parent variables + comments would clear it up?


Br,
	Matti Vaittinen