include/acpi/acpi_device.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Generation of tables for particular device types
 *
 * Copyright 2019 Google LLC
 * Mostly taken from coreboot file of the same name
 */

#ifndef __ACPI_DEVICE_H
#define __ACPI_DEVICE_H

#include <linux/bitops.h>

struct acpi_ctx;
struct gpio_desc;
struct irq;
struct udevice;

/* ACPI descriptor values for common descriptors: SERIAL_BUS means I2C */
#define ACPI_DESCRIPTOR_LARGE		BIT(7)
#define ACPI_DESCRIPTOR_INTERRUPT	(ACPI_DESCRIPTOR_LARGE | 9)
#define ACPI_DESCRIPTOR_GPIO		(ACPI_DESCRIPTOR_LARGE | 12)
#define ACPI_DESCRIPTOR_SERIAL_BUS	(ACPI_DESCRIPTOR_LARGE | 14)

/* Length of a full path to an ACPI device */
#define ACPI_PATH_MAX		30

/* Values that can be returned for ACPI device _STA method */
enum acpi_dev_status {
	ACPI_DSTATUS_PRESENT		= BIT(0),
	ACPI_DSTATUS_ENABLED		= BIT(1),
	ACPI_DSTATUS_SHOW_IN_UI		= BIT(2),
	ACPI_DSTATUS_OK			= BIT(3),
	ACPI_DSTATUS_HAS_BATTERY	= BIT(4),

	ACPI_DSTATUS_ALL_OFF	= 0,
	ACPI_DSTATUS_HIDDEN_ON	= ACPI_DSTATUS_PRESENT | ACPI_DSTATUS_ENABLED |
		ACPI_DSTATUS_OK,
	ACPI_DSTATUS_ALL_ON	= ACPI_DSTATUS_HIDDEN_ON |
		ACPI_DSTATUS_SHOW_IN_UI,
};

/** enum acpi_irq_mode - edge/level trigger mode */
enum acpi_irq_mode {
	ACPI_IRQ_EDGE_TRIGGERED,
	ACPI_IRQ_LEVEL_TRIGGERED,
};

/**
 * enum acpi_irq_polarity - polarity of interrupt
 *
 * @ACPI_IRQ_ACTIVE_LOW - for ACPI_IRQ_EDGE_TRIGGERED this means falling edge
 * @ACPI_IRQ_ACTIVE_HIGH - for ACPI_IRQ_EDGE_TRIGGERED this means rising edge
 * @ACPI_IRQ_ACTIVE_BOTH - not meaningful for ACPI_IRQ_EDGE_TRIGGERED
 */
enum acpi_irq_polarity {
	ACPI_IRQ_ACTIVE_LOW,
	ACPI_IRQ_ACTIVE_HIGH,
	ACPI_IRQ_ACTIVE_BOTH,
};

/**
 * enum acpi_irq_shared - whether interrupt is shared or not
 *
 * @ACPI_IRQ_EXCLUSIVE: only this device uses the interrupt
 * @ACPI_IRQ_SHARED: other devices may use this interrupt
 */
enum acpi_irq_shared {
	ACPI_IRQ_EXCLUSIVE,
	ACPI_IRQ_SHARED,
};

/** enum acpi_irq_wake - indicates whether this interrupt can wake the device */
enum acpi_irq_wake {
	ACPI_IRQ_NO_WAKE,
	ACPI_IRQ_WAKE,
};

/**
 * struct acpi_irq - representation of an ACPI interrupt
 *
 * @pin: ACPI pin that is monitored for the interrupt
 * @mode: Edge/level triggering
 * @polarity: Interrupt polarity
 * @shared: Whether interrupt is shared or not
 * @wake: Whether interrupt can wake the device from sleep
 */
struct acpi_irq {
	unsigned int pin;
	enum acpi_irq_mode mode;
	enum acpi_irq_polarity polarity;
	enum acpi_irq_shared shared;
	enum acpi_irq_wake wake;
};

/**
 * 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
 * and ZZZZ is the device. All parent devices are added to the path.
 *
 * @dev: Device to check
 * @buf: Buffer to place the path in (should be ACPI_PATH_MAX long)
 * @maxlen: Size of buffer (typically ACPI_PATH_MAX)
 * @return 0 if OK, -ve on error
 */
int acpi_device_path(const struct udevice *dev, char *buf, int maxlen);

/**
 * acpi_device_scope() - Get the scope of an ACPI device
 *
 * This gets the scope which is the full path of the parent device, as per
 * acpi_device_path().
 *
 * @dev: Device to check
 * @buf: Buffer to place the path in (should be ACPI_PATH_MAX long)
 * @maxlen: Size of buffer (typically ACPI_PATH_MAX)
 * @return 0 if OK, -EINVAL if the device has no parent, other -ve on other
 *	error
 */
int acpi_device_scope(const struct udevice *dev, char *scope, int maxlen);

/**
 * acpi_device_status() - Get the status of a device
 *
 * This currently just returns ACPI_DSTATUS_ALL_ON. It does not support
 * inactive or hidden devices.
 *
 * @dev: Device to check
 * @return device status, as ACPI_DSTATUS_...
 */
enum acpi_dev_status acpi_device_status(const struct udevice *dev);

/**
 * acpi_device_write_interrupt_irq() - Write an interrupt descriptor
 *
 * This writes an ACPI interrupt descriptor for the given interrupt, converting
 * fields as needed.
 *
 * @ctx: ACPI context pointer
 * @req_irq: Interrupt to output
 * @return IRQ pin number if OK, -ve on error
 */
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);

/**
 * acpi_device_write_interrupt_or_gpio() - Write interrupt or GPIO to ACPI
 *
 * This reads an interrupt from the device tree "interrupts-extended" property,
 * if available. If not it reads the first GPIO with the name @prop.
 *
 * If an interrupt is found, an ACPI interrupt descriptor is written to the ACPI
 * output. If not, but if a GPIO is found, a GPIO descriptor is written.
 *
 * @return irq or GPIO pin number if OK, -ve if neither an interrupt nor a GPIO
 *	could be found, or some other error occurred
 */
int acpi_device_write_interrupt_or_gpio(struct acpi_ctx *ctx,
					struct udevice *dev, const char *prop);

#endif