Vlv2TbltDevicePkg/Include/Protocol/I2cHostMcg.h

   1 /*++
   2
   3   Copyright (c) 2004  - 2014, Intel Corporation. All rights reserved.<BR>
   4
   5   SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7
   8
   9 **/
  10
  11 #ifndef __I2C_HOST_H__
  12 #define __I2C_HOST_H__
  13
  14 #include <Protocol/I2cMasterMcg.h>
  15
  16 /**
  17   Declare the forward references
  18
  19 **/
  20 typedef struct _EFI_I2C_HOST_PROTOCOL EFI_I2C_HOST_PROTOCOL;
  21 typedef struct _EFI_I2C_HOST_CALLBACKS EFI_I2C_HOST_CALLBACKS;
  22
  23
  24 /**
  25   Queue an I2C operation for execution on the I2C controller.
  26
  27   This routine must be called at or below TPL_NOTIFY.  For synchronous
  28   requests this routine must be called at or below TPL_CALLBACK.
  29
  30   N.B. The typical consumers of this API are the I2C bus driver and
  31   on rare occasions the I2C test application.  Extreme care must be
  32   taken by other consumers of this API to prevent confusing the
  33   third party I2C drivers due to a state change at the I2C device
  34   which the third party I2C drivers did not initiate.  I2C platform
  35   drivers may use this API within these guidelines.
  36
  37   This layer uses the concept of I2C bus configurations to describe
  38   the I2C bus.  An I2C bus configuration is defined as a unique
  39   setting of the multiplexers and switches in the I2C bus which
  40   enable access to one or more I2C devices.  When using a switch
  41   to divide a bus, due to speed differences, the I2C platform layer
  42   would define an I2C bus configuration for the I2C devices on each
  43   side of the switch.  When using a multiplexer, the I2C platform
  44   layer defines an I2C bus configuration for each of the selector
  45   values required to control the multiplexer.  See Figure 1 in the
  46   <a href="http://www.nxp.com/documents/user_manual/UM10204.pdf">I<sup>2</sup>C
  47   Specification</a> for a complex I2C bus configuration.
  48
  49   The I2C host driver processes all operations in FIFO order.  Prior to
  50   performing the operation, the I2C host driver calls the I2C platform
  51   driver to reconfigure the switches and multiplexers in the I2C bus
  52   enabling access to the specified I2C device.  The I2C platform driver
  53   also selects the maximum bus speed for the device.  After the I2C bus
  54   is configured, the I2C host driver calls the I2C port driver to
  55   initialize the I2C controller and start the I2C operation.
  56
  57   @param[in] This             Address of an EFI_I2C_HOST_PROTOCOL instance.
  58   @param[in] I2cBusConfiguration  I2C bus configuration to access the I2C
  59                                   device.
  60   @param[in] SlaveAddress     Address of the device on the I2C bus.
  61   @param[in] Event            Event to set for asynchronous operations,
  62                               NULL for synchronous operations
  63   @param[in] RequestPacket    Address of an EFI_I2C_REQUEST_PACKET
  64                               structure describing the I2C operation
  65   @param[out] I2cStatus       Optional buffer to receive the I2C operation
  66                               completion status
  67
  68   @retval EFI_SUCCESS           The operation completed successfully.
  69   @retval EFI_ABORTED           The request did not complete because the driver
  70                                 was shutdown.
  71   @retval EFI_BAD_BUFFER_SIZE   The WriteBytes or ReadBytes buffer size is too large.
  72   @retval EFI_DEVICE_ERROR      There was an I2C error (NACK) during the operation.
  73                                 This could indicate the slave device is not present.
  74   @retval EFI_INVALID_PARAMETER RequestPacket is NULL
  75   @retval EFI_INVALID_PARAMETER TPL is too high
  76   @retval EFI_NO_MAPPING        Invalid I2cBusConfiguration value
  77   @retval EFI_NO_RESPONSE       The I2C device is not responding to the
  78                                 slave address.  EFI_DEVICE_ERROR may also be
  79                                 returned if the controller cannot distinguish
  80                                 when the NACK occurred.
  81   @retval EFI_NOT_FOUND         I2C slave address exceeds maximum address
  82   @retval EFI_NOT_READY         I2C bus is busy or operation pending, wait for
  83                                 the event and then read status pointed to by
  84                                 the request packet.
  85   @retval EFI_OUT_OF_RESOURCES  Insufficient memory for I2C operation
  86   @retval EFI_TIMEOUT           The transaction did not complete within an internally
  87                                 specified timeout period.
  88
  89 **/
  90 typedef
  91 EFI_STATUS
  92 (EFIAPI *EFI_I2C_HOST_QUEUE_REQUEST) (
  93   IN CONST EFI_I2C_HOST_PROTOCOL *This,
  94   IN UINTN I2cBusConfiguration,
  95   IN UINTN SlaveAddress,
  96   IN EFI_EVENT Event OPTIONAL,
  97   IN CONST EFI_I2C_REQUEST_PACKET *RequestPacket,
  98   OUT EFI_STATUS *I2cStatus OPTIONAL
  99   );
 100
 101 ///
 102 /// Host access to the I2C bus.
 103 ///
 104 struct _EFI_I2C_HOST_PROTOCOL {
 105   ///
 106   /// Queue an operation for execution on the I2C bus
 107   ///
 108   EFI_I2C_HOST_QUEUE_REQUEST QueueRequest;
 109
 110   ///
 111   /// The maximum number of I2C bus configurations
 112   ///
 113   UINTN I2cBusConfigurationCount;
 114
 115   ///
 116   /// The maximum number of bytes the I2C host controller
 117   /// is able to receive from the I2C bus.
 118   ///
 119   UINT32 MaximumReceiveBytes;
 120
 121   ///
 122   /// The maximum number of bytes the I2C host controller
 123   /// is able to send on the I2C bus.
 124   ///
 125   UINT32 MaximumTransmitBytes;
 126
 127   ///
 128   /// The maximum number of bytes in the I2C bus transaction.
 129   ///
 130   UINT32 MaximumTotalBytes;
 131 };
 132
 133 ///
 134 /// GUID for the EFI_I2C_HOST_PROTOCOL
 135 ///
 136 extern EFI_GUID gEfiI2cHostProtocolGuid;
 137
 138 #endif  //  __I2C_HOST_H__