include/acpi/acpi_device.h - platform/external/u-boot - Gitiles

 /* 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 <i2c.h>
 #include <spi.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_REGISTER	(ACPI_DESCRIPTOR_LARGE | 2)
 #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 Descriptors for Serial Bus interfaces */
 #define ACPI_SERIAL_BUS_TYPE_I2C		1
 #define ACPI_SERIAL_BUS_TYPE_SPI		2
 #define ACPI_I2C_SERIAL_BUS_REVISION_ID		1 /* TODO: upgrade to 2 */
 #define ACPI_I2C_TYPE_SPECIFIC_REVISION_ID	1
 #define ACPI_SPI_SERIAL_BUS_REVISION_ID		1
 #define ACPI_SPI_TYPE_SPECIFIC_REVISION_ID	1

 /**
  * struct acpi_i2c - representation of an ACPI I2C device
  *
  * @address: 7-bit or 10-bit I2C address
  * @mode_10bit: Which address size is used
  * @speed: Bus speed in Hz
  * @resource: Resource name for the I2C controller
  */
 struct acpi_i2c {
 	u16 address;
 	enum i2c_address_mode mode_10bit;
 	enum i2c_speed_rate speed;
 	const char *resource;
 };

 /**
  * struct acpi_spi - representation of an ACPI SPI device
  *
  * @device_select: Chip select used by this device (typically 0)
  * @device_select_polarity: Polarity for the device
  * @wire_mode: Number of wires used for SPI
  * @speed: Bus speed in Hz
  * @data_bit_length: Word length for SPI (typically 8)
  * @clock_phase: Clock phase to capture data
  * @clock_polarity: Bus polarity
  * @resource: Resource name for the SPI controller
  */
 struct acpi_spi {
 	u16 device_select;
 	enum spi_polarity device_select_polarity;
 	enum spi_wire_mode wire_mode;
 	unsigned int speed;
 	u8 data_bit_length;
 	enum spi_clock_phase clock_phase;
 	enum spi_polarity clock_polarity;
 	const char *resource;
 };

 /**
  * 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);

 /**
  * acpi_device_write_i2c_dev() - Write an I2C device to ACPI
  *
  * This creates a I2cSerialBus descriptor for an I2C device, including
  * information ACPI needs to use it.
  *
  * @ctx: ACPI context pointer
  * @dev: I2C device to write
  * @return I2C address of device if OK, -ve on error
  */
 int acpi_device_write_i2c_dev(struct acpi_ctx *ctx, const struct udevice *dev);

 /**
  * acpi_device_write_spi_dev() - Write a SPI device to ACPI
  *
  * This writes a serial bus descriptor for the SPI device so that ACPI can use
  * it
  *
  * @ctx: ACPI context pointer
  * @dev: SPI device to write
  * @return 0 if OK, -ve on error
  */
 int acpi_device_write_spi_dev(struct acpi_ctx *ctx, const struct udevice *dev);

 /**
  * acpi_device_add_power_res() - Add a basic PowerResource block for a device
  *
  * This includes GPIOs to control enable, reset and stop operation of the
  * device. Each GPIO is optional, but at least one must be provided.
  * This can be applied to any device that has power control, so is fairly
  * generic.
  *
  * Reset - Put the device into / take the device out of reset.
  * Enable - Enable / disable power to device.
  * Stop - Stop / start operation of device.
  *
  * @ctx: ACPI context pointer
  * @tx_state_val: Mask to use to toggle the TX state on the GPIO pin, e,g.
  *	PAD_CFG0_TX_STATE
  * @dw0_read: Name to use to read dw0, e.g. "\\_SB.GPC0"
  * @dw0_write: Name to use to read dw0, e.g. "\\_SB.SPC0"
  * @reset_gpio: GPIO used to take device out of reset or to put it into reset
  * @reset_delay_ms: Delay to be inserted after device is taken out of reset
  *	(_ON method delay)
  * @reset_off_delay_ms: Delay to be inserted after device is put into reset
  *	(_OFF method delay)
  * @enable_gpio: GPIO used to enable device
  * @enable_delay_ms: Delay to be inserted after device is enabled
  * @enable_off_delay_ms: Delay to be inserted after device is disabled
  *	(_OFF method delay)
  * @stop_gpio: GPIO used to stop operation of device
  * @stop_delay_ms: Delay to be inserted after disabling stop (_ON method delay)
  * @stop_off_delay_ms: Delay to be inserted after enabling stop.
  *	(_OFF method delay)
  *
  * @return 0 if OK, -ve if at least one GPIO is not provided
  */
 int acpi_device_add_power_res(struct acpi_ctx *ctx, u32 tx_state_val,
 			      const char *dw0_read, const char *dw0_write,
 			      const struct gpio_desc *reset_gpio,
 			      uint reset_delay_ms, uint reset_off_delay_ms,
 			      const struct gpio_desc *enable_gpio,
 			      uint enable_delay_ms, uint enable_off_delay_ms,
 			      const struct gpio_desc *stop_gpio,
 			      uint stop_delay_ms, uint stop_off_delay_ms);

 /**
  * acpi_device_infer_name() - Infer the name from its uclass or parent
  *
  * Many ACPI devices have a standard name that can be inferred from the uclass
  * they are in, or the uclass of their parent. These rules are implemented in
  * this function. It attempts to produce a name for a device based on these
  * rules.
  *
  * NOTE: This currently supports only x86 devices. Feel free to enhance it for
  * other architectures as needed.
  *
  * @dev: Device to check
  * @out_name: Place to put the name (must hold ACPI_NAME_MAX bytes)
  * @return 0 if a name was found, -ENOENT if not found, -ENXIO if the device
  *	sequence number could not be determined
  */
 int acpi_device_infer_name(const struct udevice *dev, char *out_name);

 #endif
	/* 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 <i2c.h>
	#include <spi.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_REGISTER (ACPI_DESCRIPTOR_LARGE \| 2)
	#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 Descriptors for Serial Bus interfaces */
	#define ACPI_SERIAL_BUS_TYPE_I2C 1
	#define ACPI_SERIAL_BUS_TYPE_SPI 2
	#define ACPI_I2C_SERIAL_BUS_REVISION_ID 1 /* TODO: upgrade to 2 */
	#define ACPI_I2C_TYPE_SPECIFIC_REVISION_ID 1
	#define ACPI_SPI_SERIAL_BUS_REVISION_ID 1
	#define ACPI_SPI_TYPE_SPECIFIC_REVISION_ID 1

	/**
	* struct acpi_i2c - representation of an ACPI I2C device
	*
	* @address: 7-bit or 10-bit I2C address
	* @mode_10bit: Which address size is used
	* @speed: Bus speed in Hz
	* @resource: Resource name for the I2C controller
	*/
	struct acpi_i2c {
	u16 address;
	enum i2c_address_mode mode_10bit;
	enum i2c_speed_rate speed;
	const char *resource;
	};

	/**
	* struct acpi_spi - representation of an ACPI SPI device
	*
	* @device_select: Chip select used by this device (typically 0)
	* @device_select_polarity: Polarity for the device
	* @wire_mode: Number of wires used for SPI
	* @speed: Bus speed in Hz
	* @data_bit_length: Word length for SPI (typically 8)
	* @clock_phase: Clock phase to capture data
	* @clock_polarity: Bus polarity
	* @resource: Resource name for the SPI controller
	*/
	struct acpi_spi {
	u16 device_select;
	enum spi_polarity device_select_polarity;
	enum spi_wire_mode wire_mode;
	unsigned int speed;
	u8 data_bit_length;
	enum spi_clock_phase clock_phase;
	enum spi_polarity clock_polarity;
	const char *resource;
	};

	/**
	* 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);

	/**
	* acpi_device_write_i2c_dev() - Write an I2C device to ACPI
	*
	* This creates a I2cSerialBus descriptor for an I2C device, including
	* information ACPI needs to use it.
	*
	* @ctx: ACPI context pointer
	* @dev: I2C device to write
	* @return I2C address of device if OK, -ve on error
	*/
	int acpi_device_write_i2c_dev(struct acpi_ctx ctx, const struct udevice dev);

	/**
	* acpi_device_write_spi_dev() - Write a SPI device to ACPI
	*
	* This writes a serial bus descriptor for the SPI device so that ACPI can use
	* it
	*
	* @ctx: ACPI context pointer
	* @dev: SPI device to write
	* @return 0 if OK, -ve on error
	*/
	int acpi_device_write_spi_dev(struct acpi_ctx ctx, const struct udevice dev);

	/**
	* acpi_device_add_power_res() - Add a basic PowerResource block for a device
	*
	* This includes GPIOs to control enable, reset and stop operation of the
	* device. Each GPIO is optional, but at least one must be provided.
	* This can be applied to any device that has power control, so is fairly
	* generic.
	*
	* Reset - Put the device into / take the device out of reset.
	* Enable - Enable / disable power to device.
	* Stop - Stop / start operation of device.
	*
	* @ctx: ACPI context pointer
	* @tx_state_val: Mask to use to toggle the TX state on the GPIO pin, e,g.
	* PAD_CFG0_TX_STATE
	* @dw0_read: Name to use to read dw0, e.g. "\\_SB.GPC0"
	* @dw0_write: Name to use to read dw0, e.g. "\\_SB.SPC0"
	* @reset_gpio: GPIO used to take device out of reset or to put it into reset
	* @reset_delay_ms: Delay to be inserted after device is taken out of reset
	* (_ON method delay)
	* @reset_off_delay_ms: Delay to be inserted after device is put into reset
	* (_OFF method delay)
	* @enable_gpio: GPIO used to enable device
	* @enable_delay_ms: Delay to be inserted after device is enabled
	* @enable_off_delay_ms: Delay to be inserted after device is disabled
	* (_OFF method delay)
	* @stop_gpio: GPIO used to stop operation of device
	* @stop_delay_ms: Delay to be inserted after disabling stop (_ON method delay)
	* @stop_off_delay_ms: Delay to be inserted after enabling stop.
	* (_OFF method delay)
	*
	* @return 0 if OK, -ve if at least one GPIO is not provided
	*/
	int acpi_device_add_power_res(struct acpi_ctx *ctx, u32 tx_state_val,
	const char dw0_read, const char dw0_write,
	const struct gpio_desc *reset_gpio,
	uint reset_delay_ms, uint reset_off_delay_ms,
	const struct gpio_desc *enable_gpio,
	uint enable_delay_ms, uint enable_off_delay_ms,
	const struct gpio_desc *stop_gpio,
	uint stop_delay_ms, uint stop_off_delay_ms);

	/**
	* acpi_device_infer_name() - Infer the name from its uclass or parent
	*
	* Many ACPI devices have a standard name that can be inferred from the uclass
	* they are in, or the uclass of their parent. These rules are implemented in
	* this function. It attempts to produce a name for a device based on these
	* rules.
	*
	* NOTE: This currently supports only x86 devices. Feel free to enhance it for
	* other architectures as needed.
	*
	* @dev: Device to check
	* @out_name: Place to put the name (must hold ACPI_NAME_MAX bytes)
	* @return 0 if a name was found, -ENOENT if not found, -ENXIO if the device
	* sequence number could not be determined
	*/
	int acpi_device_infer_name(const struct udevice dev, char out_name);

	#endif