On Tue, Dec 07, 2021 at 10:34:07AM +0100, Bartosz Golaszewski wrote:
> Software nodes allow us to represent hierarchies for device components
> that don't have their struct device representation yet - for instance:
> banks of GPIOs under a common GPIO expander. The core gpiolib core
> however doesn't offer any way of passing this information from the
> drivers.
>
> This extends struct gpio_chip with a pointer to fwnode that can be set
> by the driver and used to pass device properties for child nodes.
>
> This is similar to how we handle device-tree sub-nodes with
> CONFIG_OF_GPIO enabled.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> Signed-off-by: Bartosz Golaszewski <brgl@xxxxxxxx>
> ---
> drivers/gpio/gpiolib.c | 7 ++++++-
> include/linux/gpio/driver.h | 2 ++
> 2 files changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index 22b98a590a88..6af732bf4c99 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -593,13 +593,18 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
> struct lock_class_key *lock_key,
> struct lock_class_key *request_key)
> {
> - struct fwnode_handle *fwnode = gc->parent ? dev_fwnode(gc->parent) : NULL;
> + struct fwnode_handle *fwnode = NULL;
> unsigned long flags;
> int ret = 0;
> unsigned i;
> int base = gc->base;
> struct gpio_device *gdev;
>
> + if (gc->fwnode)
> + fwnode = gc->fwnode;
> + else if (gc->parent)
> + fwnode = dev_fwnode(gc->parent);
> +
> /*
> * First: allocate and populate the internal stat container, and
> * set up the struct device.
> diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
> index a673a359e20b..b0728c8ad90c 100644
> --- a/include/linux/gpio/driver.h
> +++ b/include/linux/gpio/driver.h
> @@ -289,6 +289,7 @@ struct gpio_irq_chip {
> * number or the name of the SoC IP-block implementing it.
> * @gpiodev: the internal state holder, opaque struct
> * @parent: optional parent device providing the GPIOs
> + * @fwnode: optional fwnode providing this controller's properties
> * @owner: helps prevent removal of modules exporting active GPIOs
> * @request: optional hook for chip-specific activation, such as
> * enabling module power and clock; may sleep
> @@ -377,6 +378,7 @@ struct gpio_chip {
> const char *label;
> struct gpio_device *gpiodev;
> struct device *parent;
> + struct fwnode_handle *fwnode;
> struct module *owner;
>
> int (*request)(struct gpio_chip *gc,
> --
> 2.25.1
>
--
With Best Regards,
Andy Shevchenko
