Le mercredi 24 janvier 2024 à 16:04 +0100, Bartosz Golaszewski a
écrit :
> On Wed, Jan 24, 2024 at 3:59 PM Paul Cercueil <paul@xxxxxxxxxxxxxxx>
> wrote:
> >
> > Hi Bartosz,
> >
> > Le mardi 05 septembre 2023 à 20:53 +0200, Bartosz Golaszewski a
> > écrit :
> > > From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> > >
> > > We're porting all users of gpiochip_find() to using
> > > gpio_device_find().
> > > Update the swnode GPIO code.
> > >
> > > Signed-off-by: Bartosz Golaszewski
> > > <bartosz.golaszewski@xxxxxxxxxx>
> > > ---
> > > drivers/gpio/gpiolib-swnode.c | 29 ++++++++++++-----------------
> > > 1 file changed, 12 insertions(+), 17 deletions(-)
> > >
> > > diff --git a/drivers/gpio/gpiolib-swnode.c
> > > b/drivers/gpio/gpiolib-
> > > swnode.c
> > > index b5a6eaf3729b..56c8519be538 100644
> > > --- a/drivers/gpio/gpiolib-swnode.c
> > > +++ b/drivers/gpio/gpiolib-swnode.c
> > > @@ -31,31 +31,26 @@ static void swnode_format_propname(const char
> > > *con_id, char *propname,
> > > strscpy(propname, "gpios", max_size);
> > > }
> > >
> > > -static int swnode_gpiochip_match_name(struct gpio_chip *chip,
> > > void
> > > *data)
> > > +static struct gpio_device *swnode_get_gpio_device(struct
> > > fwnode_handle *fwnode)
> > > {
> > > - return !strcmp(chip->label, data);
> > > -}
> > > + const struct software_node *gdev_node;
> > > + struct gpio_device *gdev;
> > >
> > > -static struct gpio_chip *swnode_get_chip(struct fwnode_handle
> > > *fwnode)
> > > -{
> > > - const struct software_node *chip_node;
> > > - struct gpio_chip *chip;
> > > -
> > > - chip_node = to_software_node(fwnode);
> > > - if (!chip_node || !chip_node->name)
> > > + gdev_node = to_software_node(fwnode);
> > > + if (!gdev_node || !gdev_node->name)
> > > return ERR_PTR(-EINVAL);
> > >
> > > - chip = gpiochip_find((void *)chip_node->name,
> > > swnode_gpiochip_match_name);
> > > - return chip ?: ERR_PTR(-EPROBE_DEFER);
> > > + gdev = gpio_device_find_by_label((void *)gdev_node->name);
> > > + return gdev ?: ERR_PTR(-EPROBE_DEFER);
> > > }
> > >
> > > struct gpio_desc *swnode_find_gpio(struct fwnode_handle *fwnode,
> > > const char *con_id, unsigned int
> > > idx,
> > > unsigned long *flags)
> > > {
> > > + struct gpio_device *gdev __free(gpio_device_put) = NULL;
> > > const struct software_node *swnode;
> > > struct fwnode_reference_args args;
> > > - struct gpio_chip *chip;
> > > struct gpio_desc *desc;
> > > char propname[32]; /* 32 is max size of property name */
> > > int error;
> > > @@ -77,12 +72,12 @@ struct gpio_desc *swnode_find_gpio(struct
> > > fwnode_handle *fwnode,
> > > return ERR_PTR(error);
> > > }
> > >
> > > - chip = swnode_get_chip(args.fwnode);
> > > + gdev = swnode_get_gpio_device(args.fwnode);
> > > fwnode_handle_put(args.fwnode);
> > > - if (IS_ERR(chip))
> > > - return ERR_CAST(chip);
> > > + if (IS_ERR(gdev))
> > > + return ERR_CAST(gdev);
> >
> > I'm a bit late to the party, sorry.
> >
> > I'm looking at how __free() should be used to use it in my own
> > patchset, and I was wondering if this code actually works.
> >
> > What happens if swnode_get_gpio_device() returns an error pointer?
> > Won't that cause a call to gpio_device_put() with the invalid
> > pointer?
> >
> > Cheers,
> > -Paul
> >
>
> No. because the __free() callback is defined as:
>
> DEFINE_FREE(gpio_device_put, struct gpio_device *,
> if (!IS_ERR_OR_NULL(_T)) gpio_device_put(_T))
Ok. I missed this.
I would argue that it's still not right though - it should probably use
IS_ERR() instead. gpio_device_put() only happens to accept NULL
pointers because the "dev" field is at the very beginning of the
"gpio_device" struct. I'm not sure this works with e.g.
CONFIG_RANDSTRUCT_FULL.
> Bart
Cheers,
-Paul
> > >
> > > - desc = gpiochip_get_desc(chip, args.args[0]);
> > > + desc = gpiochip_get_desc(gdev->chip, args.args[0]);
> > > *flags = args.args[1]; /* We expect native GPIO flags */
> > >
> > > pr_debug("%s: parsed '%s' property of node '%pfwP[%d]' -
> > > status (%d)\n",
> >
