gpio: Add a method to convert a GPIO to ACPI
When generating ACPI tables we need to convert GPIOs in U-Boot to the ACPI
structures required by ACPI. This is a SoC-specific conversion and cannot
be handled by generic code, so add a new GPIO method to do the conversion.
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/include/acpi/acpi_device.h b/include/acpi/acpi_device.h
index e72fede..69b90968 100644
--- a/include/acpi/acpi_device.h
+++ b/include/acpi/acpi_device.h
@@ -93,6 +93,96 @@
};
/**
+ * enum acpi_gpio_type - type of the descriptor
+ *
+ * @ACPI_GPIO_TYPE_INTERRUPT: GpioInterrupt
+ * @ACPI_GPIO_TYPE_IO: GpioIo
+ */
+enum acpi_gpio_type {
+ ACPI_GPIO_TYPE_INTERRUPT,
+ ACPI_GPIO_TYPE_IO,
+};
+
+/**
+ * enum acpi_gpio_pull - pull direction
+ *
+ * @ACPI_GPIO_PULL_DEFAULT: Use default value for pin
+ * @ACPI_GPIO_PULL_UP: Pull up
+ * @ACPI_GPIO_PULL_DOWN: Pull down
+ * @ACPI_GPIO_PULL_NONE: No pullup/pulldown
+ */
+enum acpi_gpio_pull {
+ ACPI_GPIO_PULL_DEFAULT,
+ ACPI_GPIO_PULL_UP,
+ ACPI_GPIO_PULL_DOWN,
+ ACPI_GPIO_PULL_NONE,
+};
+
+/**
+ * enum acpi_gpio_io_restrict - controls input/output of pin
+ *
+ * @ACPI_GPIO_IO_RESTRICT_NONE: no restrictions
+ * @ACPI_GPIO_IO_RESTRICT_INPUT: input only (no output)
+ * @ACPI_GPIO_IO_RESTRICT_OUTPUT: output only (no input)
+ * @ACPI_GPIO_IO_RESTRICT_PRESERVE: preserve settings when driver not active
+ */
+enum acpi_gpio_io_restrict {
+ ACPI_GPIO_IO_RESTRICT_NONE,
+ ACPI_GPIO_IO_RESTRICT_INPUT,
+ ACPI_GPIO_IO_RESTRICT_OUTPUT,
+ ACPI_GPIO_IO_RESTRICT_PRESERVE,
+};
+
+/** enum acpi_gpio_polarity - controls the GPIO polarity */
+enum acpi_gpio_polarity {
+ ACPI_GPIO_ACTIVE_HIGH = 0,
+ ACPI_GPIO_ACTIVE_LOW = 1,
+};
+
+#define ACPI_GPIO_REVISION_ID 1
+#define ACPI_GPIO_MAX_PINS 2
+
+/**
+ * struct acpi_gpio - representation of an ACPI GPIO
+ *
+ * @pin_count: Number of pins represented
+ * @pins: List of pins
+ * @pin0_addr: Address in memory of the control registers for pin 0. This is
+ * used when generating ACPI tables
+ * @type: GPIO type
+ * @pull: Pullup/pulldown setting
+ * @resource: Resource name for this GPIO controller
+ * For GpioInt:
+ * @interrupt_debounce_timeout: Debounce timeout in units of 10us
+ * @irq: Interrupt
+ *
+ * For GpioIo:
+ * @output_drive_strength: Drive strength in units of 10uA
+ * @io_shared; true if GPIO is shared
+ * @io_restrict: I/O restriction setting
+ * @polarity: GPIO polarity
+ */
+struct acpi_gpio {
+ int pin_count;
+ u16 pins[ACPI_GPIO_MAX_PINS];
+ ulong pin0_addr;
+
+ enum acpi_gpio_type type;
+ enum acpi_gpio_pull pull;
+ char resource[ACPI_PATH_MAX];
+
+ /* GpioInt */
+ u16 interrupt_debounce_timeout;
+ struct acpi_irq irq;
+
+ /* GpioIo */
+ u16 output_drive_strength;
+ bool io_shared;
+ enum acpi_gpio_io_restrict io_restrict;
+ enum acpi_gpio_polarity polarity;
+};
+
+/**
* acpi_device_path() - Get the full path to an ACPI device
*
* This gets the full path in the form XXXX.YYYY.ZZZZ where XXXX is the root
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index e16c2f3..a57dd26 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -10,6 +10,7 @@
#include <dm/ofnode.h>
#include <linux/bitops.h>
+struct acpi_gpio;
struct ofnode_phandle_args;
/*
@@ -329,6 +330,20 @@
*/
int (*get_dir_flags)(struct udevice *dev, unsigned int offset,
ulong *flags);
+
+#if CONFIG_IS_ENABLED(ACPIGEN)
+ /**
+ * get_acpi() - Get the ACPI info for a GPIO
+ *
+ * This converts a GPIO to an ACPI structure for adding to the ACPI
+ * tables.
+ *
+ * @desc: GPIO description to convert
+ * @gpio: Output ACPI GPIO information
+ * @return ACPI pin number or -ve on error
+ */
+ int (*get_acpi)(const struct gpio_desc *desc, struct acpi_gpio *gpio);
+#endif
};
/**
@@ -674,4 +689,16 @@
*/
int gpio_get_number(const struct gpio_desc *desc);
+/**
+ * gpio_get_acpi() - Get the ACPI pin for a GPIO
+ *
+ * This converts a GPIO to an ACPI pin number for adding to the ACPI
+ * tables. If the GPIO is invalid, the pin_count and pins[0] are set to 0
+ *
+ * @desc: GPIO description to convert
+ * @gpio: Output ACPI GPIO information
+ * @return ACPI pin number or -ve on error
+ */
+int gpio_get_acpi(const struct gpio_desc *desc, struct acpi_gpio *gpio);
+
#endif /* _ASM_GENERIC_GPIO_H_ */