MdePkg/Include/Protocol/I2cIo.h

   1 /** @file
   2   I2C I/O Protocol as defined in the PI 1.3 specification.
   3
   4   The EFI I2C I/O protocol enables the user to manipulate a single
   5   I2C device independent of the host controller and I2C design.
   6
   7   Copyright (c) 2013 - 2018, Intel Corporation. All rights reserved.<BR>
   8   SPDX-License-Identifier: BSD-2-Clause-Patent
   9
  10   @par Revision Reference:
  11   This protocol is from PI Version 1.3.
  12
  13 **/
  14
  15 #ifndef __I2C_IO_H__
  16 #define __I2C_IO_H__
  17
  18 #include <Pi/PiI2c.h>
  19
  20 #define EFI_I2C_IO_PROTOCOL_GUID { 0xb60a3e6b, 0x18c4, 0x46e5, { 0xa2, 0x9a, 0xc9, 0xa1, 0x06, 0x65, 0xa2, 0x8e }}
  21
  22 ///
  23 /// I2C I/O protocol
  24 ///
  25 /// The I2C IO protocol enables access to a specific device on the I2C
  26 /// bus.
  27 ///
  28 /// Each I2C device is identified uniquely in the system by the tuple
  29 /// DeviceGuid:DeviceIndex.  The DeviceGuid represents the manufacture
  30 /// and part number and is provided by the silicon vendor or the third
  31 /// party I2C device driver writer.  The DeviceIndex identifies the part
  32 /// within the system by using a unique number and is created by the
  33 /// board designer or the writer of the EFI_I2C_ENUMERATE_PROTOCOL.
  34 ///
  35 /// I2C slave addressing is abstracted to validate addresses and limit
  36 /// operation to the specified I2C device.  The third party providing
  37 /// the I2C device support provides an ordered list of slave addresses
  38 /// for the I2C device required to implement the EFI_I2C_ENUMERATE_PROTOCOL.
  39 /// The order of the list must be preserved.
  40 ///
  41 typedef struct _EFI_I2C_IO_PROTOCOL  EFI_I2C_IO_PROTOCOL;
  42
  43
  44 /**
  45   Queue an I2C transaction for execution on the I2C device.
  46
  47   This routine must be called at or below TPL_NOTIFY.  For synchronous
  48   requests this routine must be called at or below TPL_CALLBACK.
  49
  50   This routine queues an I2C transaction to the I2C controller for
  51   execution on the I2C bus.
  52
  53   When Event is NULL, QueueRequest() operates synchronously and returns
  54   the I2C completion status as its return value.
  55
  56   When Event is not NULL, QueueRequest() synchronously returns EFI_SUCCESS
  57   indicating that the asynchronous I2C transaction was queued.  The values
  58   above are returned in the buffer pointed to by I2cStatus upon the
  59   completion of the I2C transaction when I2cStatus is not NULL.
  60
  61   The upper layer driver writer provides the following to the platform
  62   vendor:
  63
  64   1.  Vendor specific GUID for the I2C part
  65   2.  Guidance on proper construction of the slave address array when the
  66       I2C device uses more than one slave address.  The I2C bus protocol
  67       uses the SlaveAddressIndex to perform relative to physical address
  68       translation to access the blocks of hardware within the I2C device.
  69
  70   @param[in] This               Pointer to an EFI_I2C_IO_PROTOCOL structure.
  71   @param[in] SlaveAddressIndex  Index value into an array of slave addresses
  72                                 for the I2C device.  The values in the array
  73                                 are specified by the board designer, with the
  74                                 third party I2C device driver writer providing
  75                                 the slave address order.
  76
  77                                 For devices that have a single slave address,
  78                                 this value must be zero.  If the I2C device
  79                                 uses more than one slave address then the
  80                                 third party (upper level) I2C driver writer
  81                                 needs to specify the order of entries in the
  82                                 slave address array.
  83
  84                                 \ref ThirdPartyI2cDrivers "Third Party I2C
  85                                 Drivers" section in I2cMaster.h.
  86   @param[in] Event              Event to signal for asynchronous transactions,
  87                                 NULL for synchronous transactions
  88   @param[in] RequestPacket      Pointer to an EFI_I2C_REQUEST_PACKET structure
  89                                 describing the I2C transaction
  90   @param[out] I2cStatus         Optional buffer to receive the I2C transaction
  91                                 completion status
  92
  93   @retval EFI_SUCCESS           The asynchronous transaction was successfully
  94                                 queued when Event is not NULL.
  95   @retval EFI_SUCCESS           The transaction completed successfully when
  96                                 Event is NULL.
  97   @retval EFI_BAD_BUFFER_SIZE   The RequestPacket->LengthInBytes value is too
  98                                 large.
  99   @retval EFI_DEVICE_ERROR      There was an I2C error (NACK) during the
 100                                 transaction.
 101   @retval EFI_INVALID_PARAMETER RequestPacket is NULL.
 102   @retval EFI_NO_MAPPING        The EFI_I2C_HOST_PROTOCOL could not set the
 103                                 bus configuration required to access this I2C
 104                                 device.
 105   @retval EFI_NO_RESPONSE       The I2C device is not responding to the slave
 106                                 address selected by SlaveAddressIndex.
 107                                 EFI_DEVICE_ERROR will be returned if the
 108                                 controller cannot distinguish when the NACK
 109                                 occurred.
 110   @retval EFI_OUT_OF_RESOURCES  Insufficient memory for I2C transaction
 111   @retval EFI_UNSUPPORTED       The controller does not support the requested
 112                                 transaction.
 113
 114 **/
 115 typedef
 116 EFI_STATUS
 117 (EFIAPI *EFI_I2C_IO_PROTOCOL_QUEUE_REQUEST) (
 118   IN CONST EFI_I2C_IO_PROTOCOL  *This,
 119   IN UINTN                      SlaveAddressIndex,
 120   IN EFI_EVENT                  Event      OPTIONAL,
 121   IN EFI_I2C_REQUEST_PACKET     *RequestPacket,
 122   OUT EFI_STATUS                *I2cStatus OPTIONAL
 123   );
 124
 125 ///
 126 /// I2C I/O protocol
 127 ///
 128 struct _EFI_I2C_IO_PROTOCOL {
 129   ///
 130   /// Queue an I2C transaction for execution on the I2C device.
 131   ///
 132   EFI_I2C_IO_PROTOCOL_QUEUE_REQUEST         QueueRequest;
 133
 134   ///
 135   /// Unique value assigned by the silicon manufacture or the third
 136   /// party I2C driver writer for the I2C part.  This value logically
 137   /// combines both the manufacture name and the I2C part number into
 138   /// a single value specified as a GUID.
 139   ///
 140   CONST EFI_GUID                            *DeviceGuid;
 141
 142   ///
 143   /// Unique ID of the I2C part within the system
 144   ///
 145   UINT32                                    DeviceIndex;
 146
 147   ///
 148   /// Hardware revision - ACPI _HRV value.  See the Advanced Configuration
 149   /// and Power Interface Specification, Revision 5.0  for the field format
 150   /// and the Plug and play support for I2C web-page for restriction on values.
 151   ///
 152   UINT32                                    HardwareRevision;
 153
 154   ///
 155   /// Pointer to an EFI_I2C_CONTROLLER_CAPABILITIES data structure containing
 156   /// the capabilities of the I2C host controller.
 157   ///
 158   CONST EFI_I2C_CONTROLLER_CAPABILITIES     *I2cControllerCapabilities;
 159 };
 160
 161 ///
 162 /// Reference to variable defined in the .DEC file
 163 ///
 164 extern EFI_GUID gEfiI2cIoProtocolGuid;
 165
 166 #endif  //  __I2C_IO_H__