1 files changed, 64 insertions, 0 deletions
diff --git a/Platform/Marvell/Documentation/Drivers/I2cDriver.txt b/Platform/Marvell/Documentation/Drivers/I2cDriver.txt
new file mode 100644
index 0000000000..2f890de3db
--- /dev/null
+++ b/Platform/Marvell/Documentation/Drivers/I2cDriver.txt
@@ -0,0 +1,64 @@
+1. Introduction
+---------------
+**MvI2cDxe** is a driver supporting I2C controller on Marvell SOCs boards.
+It is connected through protocols to generic UEFI I2C stack, which exposes
+IO functionality to drivers of specific devices on I2C bus.
+
+2. MvI2cDxe driver design
+--------------------------
+MvI2cDxe produces several protocols from generic I2C stack:
+ - EFI_I2C_MASTER_PROTOCOL,
+ - EFI_I2C_ENUMERATE_PROTOCOL,
+ - EFI_I2C_BUS_CONFIGURATION_MANAGEMENT_PROTOCOL
+ - general-purpose EFI_DRIVER_BINDING_PROTOCOL.
+
+  2.1 EFI_I2C_MASTER_PROTOCOL
+  ---------------------------
+  This is the most important protocol produced by MvI2cDxe. Following functions
+  are implemented:
+
+      ///
+      /// 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;
+
+    StartRequest and Reset functions are used by I2cHost.
+    These should **not** be used by I2C device drivers - required
+    synchronization is not provided. Instead, members of EFI_I2C_IO_PROTOCOL
+    should be used.
+
+  2.2 EFI_I2C_BUS_CONFIGURATION_MANAGEMENT_PROTOCOL
+  -------------------------------------------------
+  The only function exposed via this protocol is MvI2cEnableConf. It is
+  required by I2C stack in order to allow changing I2C bus configuration from
+  device drivers.
+
+  2.3 EFI_I2C_ENUMERATE_PROTOCOL
+  ------------------------------
+  Provides Enumerate function, which is used by I2cBus code as an iterator over
+  devices on I2C bus.
+
+    typedef
+    EFI_STATUS
+    (EFIAPI *EFI_I2C_ENUMERATE_PROTOCOL_ENUMERATE) (
+      IN CONST EFI_I2C_ENUMERATE_PROTOCOL *This,
+      IN OUT CONST EFI_I2C_DEVICE         **Device
+    );
+
+    ///
+    /// Traverse the set of I2C devices on an I2C bus.  This routine
+    /// returns the next I2C device on an I2C bus.
+    ///
+    EFI_I2C_ENUMERATE_PROTOCOL_ENUMERATE         Enumerate;
+
+  MvI2cDevice creates EFI_I2C_DEVICE structure for every device on the bus.
+  Due to the fact that hardware-based I2C enumeration isn't safe, information
+  about attached devices should be provided through PCDs. After EFI_I2C_DEVICE
+  structure is created and filled properly, it is returned to I2cBus. It is
+  followed by attachment of I2C device driver.
+