[PATCH] gpio: set device type for GPIO chips

[PATCH] gpio: set device type for GPIO chips

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

It's useful to have the device type information for those sub-devices
that are actually GPIO chips registered with GPIOLIB. While at it: use
the device type struct to setup the release callback which is the
preferred way to use the device API.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
 drivers/gpio/gpiolib.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index d50a786f8176..6b1f16c15deb 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -663,6 +663,11 @@ static void gpiodev_release(struct device *dev)
 	kfree(gdev);
 }
 
+static struct device_type gpio_dev_type = {
+	.name = "gpio_chip",
+	.release = gpiodev_release,
+};
+
 #ifdef CONFIG_GPIO_CDEV
 #define gcdev_register(gdev, devt)	gpiolib_cdev_register((gdev), (devt))
 #define gcdev_unregister(gdev)		gpiolib_cdev_unregister((gdev))
@@ -680,6 +685,8 @@ static int gpiochip_setup_dev(struct gpio_device *gdev)
 	struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev);
 	int ret;
 
+	device_initialize(&gdev->dev);
+
 	/*
 	 * If fwnode doesn't belong to another device, it's safe to clear its
 	 * initialized flag.
@@ -691,9 +698,6 @@ static int gpiochip_setup_dev(struct gpio_device *gdev)
 	if (ret)
 		return ret;
 
-	/* From this point, the .release() function cleans up gpio_device */
-	gdev->dev.release = gpiodev_release;
-
 	ret = gpiochip_sysfs_register(gdev);
 	if (ret)
 		goto err_remove_device;
@@ -825,6 +829,8 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
 	gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
 	if (!gdev)
 		return -ENOMEM;
+
+	gdev->dev.type = &gpio_dev_type;
 	gdev->dev.bus = &gpio_bus_type;
 	gdev->dev.parent = gc->parent;
 	gdev->chip = gc;
@@ -851,7 +857,6 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
 	if (ret)
 		goto err_free_ida;
 
-	device_initialize(&gdev->dev);
 	if (gc->parent && gc->parent->driver)
 		gdev->owner = gc->parent->driver->owner;
 	else if (gc->owner)
-- 
2.40.1

Re: [PATCH] gpio: set device type for GPIO chips

[Linus Walleij]

On Thu, Feb 1, 2024 at 5:28 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote:

> From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
>
> It's useful to have the device type information for those sub-devices
> that are actually GPIO chips registered with GPIOLIB. While at it: use
> the device type struct to setup the release callback which is the
> preferred way to use the device API.
>
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
(...=
> +static struct device_type gpio_dev_type = {
> +       .name = "gpio_chip",
> +       .release = gpiodev_release,
> +};
> +       gdev->dev.type = &gpio_dev_type;
>         gdev->dev.bus = &gpio_bus_type;
>         gdev->dev.parent = gc->parent;

Looks good to me (TM) but we should run this by Greg so he get the chance
to chime in, I doubt he will see it on LKML.

FWIW:
Acked-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij

Re: [PATCH] gpio: set device type for GPIO chips

[Greg KH]

On Wed, Feb 07, 2024 at 11:45:39AM +0100, Linus Walleij wrote:
> On Thu, Feb 1, 2024 at 5:28 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote:
> 
> > From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> >
> > It's useful to have the device type information for those sub-devices
> > that are actually GPIO chips registered with GPIOLIB. While at it: use
> > the device type struct to setup the release callback which is the
> > preferred way to use the device API.
> >
> > Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> (...=
> > +static struct device_type gpio_dev_type = {

Can you make this structure const please?

> > +       .name = "gpio_chip",
> > +       .release = gpiodev_release,
> > +};
> > +       gdev->dev.type = &gpio_dev_type;
> >         gdev->dev.bus = &gpio_bus_type;
> >         gdev->dev.parent = gc->parent;
> 
> Looks good to me (TM) but we should run this by Greg so he get the chance
> to chime in, I doubt he will see it on LKML.

Yes thanks, I wouldn't have caught it...

greg k-h

Re: [PATCH] gpio: set device type for GPIO chips

[Bartosz Golaszewski]

On Wed, Feb 7, 2024 at 11:49 AM Greg KH <gregkh@linuxfoundation.org> wrote:
>
> On Wed, Feb 07, 2024 at 11:45:39AM +0100, Linus Walleij wrote:
> > On Thu, Feb 1, 2024 at 5:28 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote:
> >
> > > From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> > >
> > > It's useful to have the device type information for those sub-devices
> > > that are actually GPIO chips registered with GPIOLIB. While at it: use
> > > the device type struct to setup the release callback which is the
> > > preferred way to use the device API.
> > >
> > > Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> > (...=
> > > +static struct device_type gpio_dev_type = {
>
> Can you make this structure const please?
>

I have, there's a v2 on the list already.

Thanks
Bart

> > > +       .name = "gpio_chip",
> > > +       .release = gpiodev_release,
> > > +};
> > > +       gdev->dev.type = &gpio_dev_type;
> > >         gdev->dev.bus = &gpio_bus_type;
> > >         gdev->dev.parent = gc->parent;
> >
> > Looks good to me (TM) but we should run this by Greg so he get the chance
> > to chime in, I doubt he will see it on LKML.
>
> Yes thanks, I wouldn't have caught it...
>
> greg k-h

Re: [PATCH] gpio: set device type for GPIO chips

[Greg KH]

On Wed, Feb 07, 2024 at 01:19:37PM +0100, Bartosz Golaszewski wrote:
> On Wed, Feb 7, 2024 at 11:49 AM Greg KH <gregkh@linuxfoundation.org> wrote:
> >
> > On Wed, Feb 07, 2024 at 11:45:39AM +0100, Linus Walleij wrote:
> > > On Thu, Feb 1, 2024 at 5:28 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote:
> > >
> > > > From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> > > >
> > > > It's useful to have the device type information for those sub-devices
> > > > that are actually GPIO chips registered with GPIOLIB. While at it: use
> > > > the device type struct to setup the release callback which is the
> > > > preferred way to use the device API.
> > > >
> > > > Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> > > (...=
> > > > +static struct device_type gpio_dev_type = {
> >
> > Can you make this structure const please?
> >
> 
> I have, there's a v2 on the list already.

Great, let me go dig that up and do a review...