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.
Signed-off-by: Bartosz Golaszewski brgl@bgdev.pl --- drivers/gpio/gpiolib.c | 15 ++++++++++++++- include/linux/gpio/driver.h | 2 ++ 2 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 22b98a590a88..2a877b4ccdee 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -593,13 +593,26 @@ 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 IS_ENABLED(CONFIG_OF_GPIO) + if (gc->of_node && gc->fwnode) { + pr_err("%s: tried to set both the of_node and fwnode in gpio_chip\n", + __func__); + return -EINVAL; + } +#endif /* CONFIG_OF_GPIO */ + + 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,