mirror of https://github.com/acidanthera/audk.git
193 lines
8.2 KiB
C
193 lines
8.2 KiB
C
/** @file
|
|
I2C Master Protocol as defined in the PI 1.3 specification.
|
|
|
|
This protocol manipulates the I2C host controller to perform transactions as a master
|
|
on the I2C bus using the current state of any switches or multiplexers in the I2C bus.
|
|
|
|
Copyright (c) 2013, Intel Corporation. All rights reserved.<BR>
|
|
This program and the accompanying materials
|
|
are licensed and made available under the terms and conditions of the BSD License
|
|
which accompanies this distribution. The full text of the license may be found at
|
|
http://opensource.org/licenses/bsd-license.php
|
|
|
|
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
|
|
|
|
@par Revision Reference:
|
|
This protocol is from PI Version 1.3.
|
|
|
|
**/
|
|
|
|
#ifndef __I2C_MASTER_H__
|
|
#define __I2C_MASTER_H__
|
|
|
|
#include <Pi/PiI2c.h>
|
|
|
|
#define EFI_I2C_MASTER_PROTOCOL_GUID { 0xcd72881f, 0x45b5, 0x4feb, { 0x98, 0xc8, 0x31, 0x3d, 0xa8, 0x11, 0x74, 0x62 }}
|
|
|
|
typedef struct _EFI_I2C_MASTER_PROTOCOL EFI_I2C_MASTER_PROTOCOL;
|
|
|
|
/**
|
|
Set the frequency for the I2C clock line.
|
|
|
|
This routine must be called at or below TPL_NOTIFY.
|
|
|
|
The software and controller do a best case effort of using the specified
|
|
frequency for the I2C bus. If the frequency does not match exactly then
|
|
the I2C master protocol selects the next lower frequency to avoid
|
|
exceeding the operating conditions for any of the I2C devices on the bus.
|
|
For example if 400 KHz was specified and the controller's divide network
|
|
only supports 402 KHz or 398 KHz then the I2C master protocol selects 398
|
|
KHz. If there are not lower frequencies available, then return
|
|
EFI_UNSUPPORTED.
|
|
|
|
@param[in] This Pointer to an EFI_I2C_MASTER_PROTOCOL structure
|
|
@param[in] BusClockHertz Pointer to the requested I2C bus clock frequency
|
|
in Hertz. Upon return this value contains the
|
|
actual frequency in use by the I2C controller.
|
|
|
|
@retval EFI_SUCCESS The bus frequency was set successfully.
|
|
@retval EFI_ALREADY_STARTED The controller is busy with another transaction.
|
|
@retval EFI_INVALID_PARAMETER BusClockHertz is NULL
|
|
@retval EFI_UNSUPPORTED The controller does not support this frequency.
|
|
|
|
**/
|
|
typedef
|
|
EFI_STATUS
|
|
(EFIAPI *EFI_I2C_MASTER_PROTOCOL_SET_BUS_FREQUENCY) (
|
|
IN CONST EFI_I2C_MASTER_PROTOCOL *This,
|
|
IN OUT UINTN *BusClockHertz
|
|
);
|
|
|
|
/**
|
|
Reset the I2C controller and configure it for use
|
|
|
|
This routine must be called at or below TPL_NOTIFY.
|
|
|
|
The I2C controller is reset. The caller must call SetBusFrequench() after
|
|
calling Reset().
|
|
|
|
@param[in] This Pointer to an EFI_I2C_MASTER_PROTOCOL structure.
|
|
|
|
@retval EFI_SUCCESS The reset completed successfully.
|
|
@retval EFI_ALREADY_STARTED The controller is busy with another transaction.
|
|
@retval EFI_DEVICE_ERROR The reset operation failed.
|
|
|
|
**/
|
|
typedef
|
|
EFI_STATUS
|
|
(EFIAPI *EFI_I2C_MASTER_PROTOCOL_RESET) (
|
|
IN CONST EFI_I2C_MASTER_PROTOCOL *This
|
|
);
|
|
|
|
/**
|
|
Start an I2C transaction on the host controller.
|
|
|
|
This routine must be called at or below TPL_NOTIFY. For synchronous
|
|
requests this routine must be called at or below TPL_CALLBACK.
|
|
|
|
This function initiates an I2C transaction on the controller. To
|
|
enable proper error handling by the I2C protocol stack, the I2C
|
|
master protocol does not support queuing but instead only manages
|
|
one I2C transaction at a time. This API requires that the I2C bus
|
|
is in the correct configuration for the I2C transaction.
|
|
|
|
The transaction is performed by sending a start-bit and selecting the
|
|
I2C device with the specified I2C slave address and then performing
|
|
the specified I2C operations. When multiple operations are requested
|
|
they are separated with a repeated start bit and the slave address.
|
|
The transaction is terminated with a stop bit.
|
|
|
|
When Event is NULL, StartRequest operates synchronously and returns
|
|
the I2C completion status as its return value.
|
|
|
|
When Event is not NULL, StartRequest synchronously returns EFI_SUCCESS
|
|
indicating that the I2C transaction was started asynchronously. The
|
|
transaction status value is returned in the buffer pointed to by
|
|
I2cStatus upon the completion of the I2C transaction when I2cStatus
|
|
is not NULL. After the transaction status is returned the Event is
|
|
signaled.
|
|
|
|
Note: The typical consumer of this API is the I2C host protocol.
|
|
Extreme care must be taken by other consumers of this API to prevent
|
|
confusing the third party I2C drivers due to a state change at the
|
|
I2C device which the third party I2C drivers did not initiate. I2C
|
|
platform specific code may use this API within these guidelines.
|
|
|
|
@param[in] This Pointer to an EFI_I2C_MASTER_PROTOCOL structure.
|
|
@param[in] SlaveAddress Address of the device on the I2C bus. Set the
|
|
I2C_ADDRESSING_10_BIT when using 10-bit addresses,
|
|
clear this bit for 7-bit addressing. Bits 0-6
|
|
are used for 7-bit I2C slave addresses and bits
|
|
0-9 are used for 10-bit I2C slave addresses.
|
|
@param[in] RequestPacket Pointer to an EFI_I2C_REQUEST_PACKET
|
|
structure describing the I2C transaction.
|
|
@param[in] Event Event to signal for asynchronous transactions,
|
|
NULL for asynchronous transactions
|
|
@param[out] I2cStatus Optional buffer to receive the I2C transaction
|
|
completion status
|
|
|
|
@retval EFI_SUCCESS The asynchronous transaction was successfully
|
|
started when Event is not NULL.
|
|
@retval EFI_SUCCESS The transaction completed successfully when
|
|
Event is NULL.
|
|
@retval EFI_ALREADY_STARTED The controller is busy with another transaction.
|
|
@retval EFI_BAD_BUFFER_SIZE The RequestPacket->LengthInBytes value is too
|
|
large.
|
|
@retval EFI_DEVICE_ERROR There was an I2C error (NACK) during the
|
|
transaction.
|
|
@retval EFI_INVALID_PARAMETER RequestPacket is NULL
|
|
@retval EFI_NOT_FOUND Reserved bit set in the SlaveAddress parameter
|
|
@retval EFI_NO_RESPONSE The I2C device is not responding to the slave
|
|
address. EFI_DEVICE_ERROR will be returned if
|
|
the controller cannot distinguish when the NACK
|
|
occurred.
|
|
@retval EFI_OUT_OF_RESOURCES Insufficient memory for I2C transaction
|
|
@retval EFI_UNSUPPORTED The controller does not support the requested
|
|
transaction.
|
|
|
|
**/
|
|
typedef
|
|
EFI_STATUS
|
|
(EFIAPI *EFI_I2C_MASTER_PROTOCOL_START_REQUEST) (
|
|
IN CONST EFI_I2C_MASTER_PROTOCOL *This,
|
|
IN UINTN SlaveAddress,
|
|
IN EFI_I2C_REQUEST_PACKET *RequestPacket,
|
|
IN EFI_EVENT Event OPTIONAL,
|
|
OUT EFI_STATUS *I2cStatus OPTIONAL
|
|
);
|
|
|
|
///
|
|
/// I2C master mode protocol
|
|
///
|
|
/// This protocol manipulates the I2C host controller to perform transactions as a
|
|
/// master on the I2C bus using the current state of any switches or multiplexers
|
|
/// in the I2C bus.
|
|
///
|
|
struct _EFI_I2C_MASTER_PROTOCOL {
|
|
///
|
|
/// Set the clock frequency for the I2C bus.
|
|
///
|
|
EFI_I2C_MASTER_PROTOCOL_SET_BUS_FREQUENCY SetBusFrequency;
|
|
|
|
///
|
|
/// Reset the I2C host controller.
|
|
///
|
|
EFI_I2C_MASTER_PROTOCOL_RESET Reset;
|
|
|
|
///
|
|
/// Start an I2C transaction in master mode on the host controller.
|
|
///
|
|
EFI_I2C_MASTER_PROTOCOL_START_REQUEST StartRequest;
|
|
|
|
///
|
|
/// Pointer to an EFI_I2C_CONTROLLER_CAPABILITIES data structure containing
|
|
/// the capabilities of the I2C host controller.
|
|
///
|
|
CONST EFI_I2C_CONTROLLER_CAPABILITIES *I2cControllerCapabilities;
|
|
};
|
|
|
|
extern EFI_GUID gEfiI2cMasterProtocolGuid;
|
|
|
|
#endif // __I2C_MASTER_H__
|