Add a data pointer to store private data in the forwarder.

Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Thomas Richard <thomas.richard@bootlin.com>
---
 drivers/gpio/gpio-aggregator.c | 20 ++++++++++++++++++--
 include/linux/gpio/forwarder.h |  4 +++-
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/drivers/gpio/gpio-aggregator.c b/drivers/gpio/gpio-aggregator.c
index 234f2f55c306..102205793015 100644
--- a/drivers/gpio/gpio-aggregator.c
+++ b/drivers/gpio/gpio-aggregator.c
@@ -268,6 +268,7 @@ struct gpiochip_fwd {
 		spinlock_t slock;	/* protects tmp[] if !can_sleep */
 	};
 	struct gpiochip_fwd_timing *delay_timings;
+	void *data;
 	unsigned long *valid_mask;
 	unsigned long tmp[];		/* values and descs for multiple ops */
 };
@@ -289,6 +290,18 @@ struct gpio_chip *gpio_fwd_get_gpiochip(struct gpiochip_fwd *fwd)
 }
 EXPORT_SYMBOL_NS_GPL(gpio_fwd_get_gpiochip, "GPIO_FORWARDER");
 
+/**
+ * gpio_fwd_get_data - Get data for the GPIO forwarder
+ * @fwd: GPIO forwarder
+ *
+ * Returns: The data for the GPIO forwarder
+ */
+void *gpio_fwd_get_data(struct gpiochip_fwd *fwd)
+{
+	return fwd->data;
+}
+EXPORT_SYMBOL_NS_GPL(gpio_fwd_get_data, "GPIO_FORWARDER");
+
 /**
  * gpio_fwd_request - Request a line of the GPIO forwarder
  * @chip: GPIO chip in the forwarder
@@ -715,10 +728,11 @@ EXPORT_SYMBOL_NS_GPL(gpio_fwd_gpio_free, "GPIO_FORWARDER");
 /**
  * gpio_fwd_register - Register a GPIO forwarder
  * @fwd: GPIO forwarder
+ * @data: driver-private data associated with this forwarder
  *
  * Returns: 0 on success, or negative errno on failure.
  */
-int gpio_fwd_register(struct gpiochip_fwd *fwd)
+int gpio_fwd_register(struct gpiochip_fwd *fwd, void *data)
 {
 	struct gpio_chip *chip = &fwd->chip;
 
@@ -734,6 +748,8 @@ int gpio_fwd_register(struct gpiochip_fwd *fwd)
 	else
 		spin_lock_init(&fwd->slock);
 
+	fwd->data = data;
+
 	return devm_gpiochip_add_data(chip->parent, chip, fwd);
 }
 EXPORT_SYMBOL_NS_GPL(gpio_fwd_register, "GPIO_FORWARDER");
@@ -778,7 +794,7 @@ static struct gpiochip_fwd *gpio_fwd_create(struct device *dev,
 			return ERR_PTR(error);
 	}
 
-	error = gpio_fwd_register(fwd);
+	error = gpio_fwd_register(fwd, NULL);
 	if (error)
 		return ERR_PTR(error);
 
diff --git a/include/linux/gpio/forwarder.h b/include/linux/gpio/forwarder.h
index f799b0377efd..dc9b0f13413d 100644
--- a/include/linux/gpio/forwarder.h
+++ b/include/linux/gpio/forwarder.h
@@ -9,6 +9,8 @@ struct gpiochip_fwd;
 
 struct gpio_chip *gpio_fwd_get_gpiochip(struct gpiochip_fwd *fwd);
 
+void *gpio_fwd_get_data(struct gpiochip_fwd *fwd);
+
 int gpio_fwd_request(struct gpio_chip *chip, unsigned int offset);
 
 int gpio_fwd_get_direction(struct gpio_chip *chip, unsigned int offset);
@@ -41,6 +43,6 @@ int gpio_fwd_gpio_add(struct gpiochip_fwd *fwd,
 
 void gpio_fwd_gpio_free(struct gpiochip_fwd *fwd, unsigned int offset);
 
-int gpio_fwd_register(struct gpiochip_fwd *fwd);
+int gpio_fwd_register(struct gpiochip_fwd *fwd, void *data);
 
 #endif

-- 
2.39.5

Hi Thomas,

On Tue, 6 May 2025 at 17:21, Thomas Richard <thomas.richard@bootlin.com> wrote:
> Add a data pointer to store private data in the forwarder.
>
> Reviewed-by: Andy Shevchenko <andy@kernel.org>
> Signed-off-by: Thomas Richard <thomas.richard@bootlin.com>

Thanks for your patch!

> --- a/drivers/gpio/gpio-aggregator.c
> +++ b/drivers/gpio/gpio-aggregator.c

> @@ -289,6 +290,18 @@ struct gpio_chip *gpio_fwd_get_gpiochip(struct gpiochip_fwd *fwd)
>  }
>  EXPORT_SYMBOL_NS_GPL(gpio_fwd_get_gpiochip, "GPIO_FORWARDER");
>
> +/**
> + * gpio_fwd_get_data - Get data for the GPIO forwarder
> + * @fwd: GPIO forwarder
> + *
> + * Returns: The data for the GPIO forwarder

driver-private data

> + */
> +void *gpio_fwd_get_data(struct gpiochip_fwd *fwd)
> +{
> +       return fwd->data;
> +}
> +EXPORT_SYMBOL_NS_GPL(gpio_fwd_get_data, "GPIO_FORWARDER");
> +
>  /**
>   * gpio_fwd_request - Request a line of the GPIO forwarder
>   * @chip: GPIO chip in the forwarder

With the above fixed:
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds