acpi: Support generation of GPIO descriptor

Add a function to write a GPIO descriptor to the generated ACPI code.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
[bmeng: Drop comment about the type always being ACPI_GPIO_TYPE_IO]
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/include/acpi/acpi_device.h b/include/acpi/acpi_device.h
index 69b90968..002e835 100644
--- a/include/acpi/acpi_device.h
+++ b/include/acpi/acpi_device.h
@@ -12,6 +12,7 @@
 #include <linux/bitops.h>
 
 struct acpi_ctx;
+struct gpio_desc;
 struct irq;
 struct udevice;
 
@@ -233,4 +234,25 @@
 int acpi_device_write_interrupt_irq(struct acpi_ctx *ctx,
 				    const struct irq *req_irq);
 
+/**
+ * acpi_device_write_gpio() - Write GpioIo() or GpioInt() descriptor
+ *
+ * @gpio: GPIO information to write
+ * @return GPIO pin number of first GPIO if OK, -ve on error
+ */
+int acpi_device_write_gpio(struct acpi_ctx *ctx, const struct acpi_gpio *gpio);
+
+/**
+ * acpi_device_write_gpio_desc() - Write a GPIO to ACPI
+ *
+ * This creates a GPIO descriptor for a GPIO, including information ACPI needs
+ * to use it.
+ *
+ * @ctx: ACPI context pointer
+ * @desc: GPIO to write
+ * @return 0 if OK, -ve on error
+ */
+int acpi_device_write_gpio_desc(struct acpi_ctx *ctx,
+				const struct gpio_desc *desc);
+
 #endif