acpi: Support writing a GPIO
Allowing writing out a reference to a GPIO within the ACPI output. This
can be used by ACPI code to access a GPIO at runtime.
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>
diff --git a/lib/acpi/acpi_dp.c b/lib/acpi/acpi_dp.c
index 32528e1..e8de565 100644
--- a/lib/acpi/acpi_dp.c
+++ b/lib/acpi/acpi_dp.c
@@ -321,3 +321,26 @@
return dp_array;
}
+
+struct acpi_dp *acpi_dp_add_gpio(struct acpi_dp *dp, const char *name,
+ const char *ref, int index, int pin,
+ enum acpi_irq_polarity polarity)
+{
+ struct acpi_dp *gpio;
+
+ assert(dp);
+ gpio = acpi_dp_new_table(name);
+ if (!gpio)
+ return NULL;
+
+ if (!acpi_dp_add_reference(gpio, NULL, ref) ||
+ !acpi_dp_add_integer(gpio, NULL, index) ||
+ !acpi_dp_add_integer(gpio, NULL, pin) ||
+ !acpi_dp_add_integer(gpio, NULL, polarity == ACPI_IRQ_ACTIVE_LOW))
+ return NULL;
+
+ if (!acpi_dp_add_array(dp, gpio))
+ return NULL;
+
+ return gpio;
+}