[PATCH v13 2/7] gpiolib: allow to specify the firmware node in struct gpio_chip

Bartosz Golaszewski
2021-12-07T09:34:31Z

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 | 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