diff options
Diffstat (limited to 'src/vendorcode/intel/edk2/UDK2017/MdePkg/Include/Protocol/I2cBusConfigurationManagement.h')
| -rw-r--r-- | src/vendorcode/intel/edk2/UDK2017/MdePkg/Include/Protocol/I2cBusConfigurationManagement.h | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/src/vendorcode/intel/edk2/UDK2017/MdePkg/Include/Protocol/I2cBusConfigurationManagement.h b/src/vendorcode/intel/edk2/UDK2017/MdePkg/Include/Protocol/I2cBusConfigurationManagement.h new file mode 100644 index 0000000000..b29333e000 --- /dev/null +++ b/src/vendorcode/intel/edk2/UDK2017/MdePkg/Include/Protocol/I2cBusConfigurationManagement.h @@ -0,0 +1,171 @@ +/** @file + I2C Bus Configuration Management Protocol as defined in the PI 1.3 specification. + + The EFI I2C bus configuration management protocol provides platform specific + services that allow the I2C host protocol to reconfigure the switches and multiplexers + and set the clock frequency for the I2C bus. This protocol also enables the I2C host protocol + to reset an I2C device which may be locking up the I2C bus by holding the clock or data line low. + + 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_BUS_CONFIGURATION_MANAGEMENT_H__ +#define __I2C_BUS_CONFIGURATION_MANAGEMENT_H__ + +#define EFI_I2C_BUS_CONFIGURATION_MANAGEMENT_PROTOCOL_GUID \ + { 0x55b71fb5, 0x17c6, 0x410e, { 0xb5, 0xbd, 0x5f, 0xa2, 0xe3, 0xd4, 0x46, 0x6b }} + +/// +/// I2C bus configuration management protocol +/// +/// The EFI I2C bus configuration management protocol provides platform +/// specific services that allow the I2C host protocol to reconfigure the +/// switches and multiplexers and set the clock frequency for the I2C bus. +/// This protocol also enables the I2C host protocol to reset an I2C device +/// which may be locking up the I2C bus by holding the clock or data line +/// low. +/// +/// The I2C protocol stack uses the concept of an I2C bus configuration as +/// a way to describe a particular state of the switches and multiplexers +/// in the I2C bus. +/// +/// A simple I2C bus does not have any multiplexers or switches is described +/// to the I2C protocol stack with a single I2C bus configuration which +/// specifies the I2C bus frequency. +/// +/// An I2C bus with switches and multiplexers use an I2C bus configuration +/// to describe each of the unique settings for the switches and multiplexers +/// and the I2C bus frequency. However the I2C bus configuration management +/// protocol only needs to define the I2C bus configurations that the software +/// uses, which may be a subset of the total. +/// +/// The I2C bus configuration description includes a list of I2C devices +/// which may be accessed when this I2C bus configuration is enabled. I2C +/// devices before a switch or multiplexer must be included in one I2C bus +/// configuration while I2C devices after a switch or multiplexer are on +/// another I2C bus configuration. +/// +/// The I2C bus configuration management protocol is an optional protocol. +/// When the I2C bus configuration protocol is not defined the I2C host +/// protocol does not start and the I2C master protocol may be used for +/// other purposes such as SMBus traffic. When the I2C bus configuration +/// protocol is available, the I2C host protocol uses the I2C bus +/// configuration protocol to call into the platform specific code to set +/// the switches and multiplexers and set the maximum I2C bus frequency. +/// +/// The platform designers determine the maximum I2C bus frequency by +/// selecting a frequency which supports all of the I2C devices on the +/// I2C bus for the setting of switches and multiplexers. The platform +/// designers must validate this against the I2C device data sheets and +/// any limits of the I2C controller or bus length. +/// +/// During I2C device enumeration, the I2C bus driver retrieves the I2C +/// bus configuration that must be used to perform I2C transactions to +/// each I2C device. This I2C bus configuration value is passed into +/// the I2C host protocol to identify the I2C bus configuration required +/// to access a specific I2C device. The I2C host protocol calls +/// EnableBusConfiguration() to set the switches and multiplexers in the +/// I2C bus and the I2C clock frequency. The I2C host protocol may +/// optimize calls to EnableBusConfiguration() by only making the call +/// when the I2C bus configuration value changes between I2C requests. +/// +/// When I2C transactions are required on the same I2C bus to change the +/// state of multiplexers or switches, the I2C master protocol must be +/// used to perform the necessary I2C transactions. +/// +/// It is up to the platform specific code to choose the proper I2C bus +/// configuration when ExitBootServices() is called. Some operating systems +/// are not able to manage the I2C bus configurations and must use the I2C +/// bus configuration that is established by the platform firmware before +/// ExitBootServices() returns. +/// +typedef struct _EFI_I2C_BUS_CONFIGURATION_MANAGEMENT_PROTOCOL EFI_I2C_BUS_CONFIGURATION_MANAGEMENT_PROTOCOL; + + +/** + Enable access to an I2C bus configuration. + + This routine must be called at or below TPL_NOTIFY. For synchronous + requests this routine must be called at or below TPL_CALLBACK. + + Reconfigure the switches and multiplexers in the I2C bus to enable + access to a specific I2C bus configuration. Also select the maximum + clock frequency for this I2C bus configuration. + + This routine uses the I2C Master protocol to perform I2C transactions + on the local bus. This eliminates any recursion in the I2C stack for + configuration transactions on the same I2C bus. This works because the + local I2C bus is idle while the I2C bus configuration is being enabled. + + If I2C transactions must be performed on other I2C busses, then the + EFI_I2C_HOST_PROTOCOL, the EFI_I2C_IO_PROTCOL, or a third party I2C + driver interface for a specific device must be used. This requirement + is because the I2C host protocol controls the flow of requests to the + I2C controller. Use the EFI_I2C_HOST_PROTOCOL when the I2C device is + not enumerated by the EFI_I2C_ENUMERATE_PROTOCOL. Use a protocol + produced by a third party driver when it is available or the + EFI_I2C_IO_PROTOCOL when the third party driver is not available but + the device is enumerated with the EFI_I2C_ENUMERATE_PROTOCOL. + + When Event is NULL, EnableI2cBusConfiguration operates synchronously + and returns the I2C completion status as its return value. + + @param[in] This Pointer to an EFI_I2C_BUS_CONFIGURATION_MANAGEMENT_PROTOCOL + structure. + @param[in] I2cBusConfiguration Index of an I2C bus configuration. All + values in the range of zero to N-1 are + valid where N is the total number of I2C + bus configurations for an I2C bus. + @param[in] Event Event to signal when the transaction is complete + @param[out] I2cStatus Buffer to receive the transaction status. + + @return When Event is NULL, EnableI2cBusConfiguration operates synchrouously + and returns the I2C completion status as its return value. In this case it is + recommended to use NULL for I2cStatus. The values returned from + EnableI2cBusConfiguration are: + + @retval EFI_SUCCESS The asynchronous bus configuration request + was successfully started when Event is not + NULL. + @retval EFI_SUCCESS The bus configuration request completed + successfully when Event is NULL. + @retval EFI_DEVICE_ERROR The bus configuration failed. + @retval EFI_NO_MAPPING Invalid I2cBusConfiguration value + +**/ +typedef +EFI_STATUS +(EFIAPI *EFI_I2C_BUS_CONFIGURATION_MANAGEMENT_PROTOCOL_ENABLE_I2C_BUS_CONFIGURATION) ( + IN CONST EFI_I2C_BUS_CONFIGURATION_MANAGEMENT_PROTOCOL *This, + IN UINTN I2cBusConfiguration, + IN EFI_EVENT Event OPTIONAL, + IN EFI_STATUS *I2cStatus OPTIONAL + ); + +/// +/// I2C bus configuration management protocol +/// +struct _EFI_I2C_BUS_CONFIGURATION_MANAGEMENT_PROTOCOL { + /// + /// Enable an I2C bus configuration for use. + /// + EFI_I2C_BUS_CONFIGURATION_MANAGEMENT_PROTOCOL_ENABLE_I2C_BUS_CONFIGURATION EnableI2cBusConfiguration; +}; + +/// +/// Reference to variable defined in the .DEC file +/// +extern EFI_GUID gEfiI2cBusConfigurationManagementProtocolGuid; + +#endif // __I2C_BUS_CONFIGURATION_MANAGEMENT_H__ |