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diff --git a/Documentation/i2c/busses/i2c-mlxcpld.rst b/Documentation/i2c/busses/i2c-mlxcpld.rst new file mode 100644 index 000000000000..9a0b2916aa71 --- /dev/null +++ b/Documentation/i2c/busses/i2c-mlxcpld.rst @@ -0,0 +1,57 @@ +================== +Driver i2c-mlxcpld +================== + +Author: Michael Shych <michaelsh@mellanox.com> + +This is the Mellanox I2C controller logic, implemented in Lattice CPLD +device. + +Device supports: + - Master mode. + - One physical bus. + - Polling mode. + +This controller is equipped within the next Mellanox systems: +"msx6710", "msx6720", "msb7700", "msn2700", "msx1410", "msn2410", "msb7800", +"msn2740", "msn2100". + +The next transaction types are supported: + - Receive Byte/Block. + - Send Byte/Block. + - Read Byte/Block. + - Write Byte/Block. + +Registers: + +=============== === ======================================================================= +CPBLTY 0x0 - capability reg. + Bits [6:5] - transaction length. b01 - 72B is supported, + 36B in other case. + Bit 7 - SMBus block read support. +CTRL 0x1 - control reg. + Resets all the registers. +HALF_CYC 0x4 - cycle reg. + Configure the width of I2C SCL half clock cycle (in 4 LPC_CLK + units). +I2C_HOLD 0x5 - hold reg. + OE (output enable) is delayed by value set to this register + (in LPC_CLK units) +CMD 0x6 - command reg. + Bit 0, 0 = write, 1 = read. + Bits [7:1] - the 7bit Address of the I2C device. + It should be written last as it triggers an I2C transaction. +NUM_DATA 0x7 - data size reg. + Number of data bytes to write in read transaction +NUM_ADDR 0x8 - address reg. + Number of address bytes to write in read transaction. +STATUS 0x9 - status reg. + Bit 0 - transaction is completed. + Bit 4 - ACK/NACK. +DATAx 0xa - 0x54 - 68 bytes data buffer regs. + For write transaction address is specified in four first bytes + (DATA1 - DATA4), data starting from DATA4. + For read transactions address is sent in a separate transaction and + specified in the four first bytes (DATA0 - DATA3). Data is read + starting from DATA0. +=============== === ======================================================================= |