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authorVadim Pasternak <vadimp@mellanox.com>2016-11-20 19:56:14 +0300
committerWolfram Sang <wsa@the-dreams.de>2016-11-24 18:21:42 +0300
commit6bec23bff914915822f2c34d0555902fb2b9be1f (patch)
treef563003de45e39e5887e0fa34f2d14f2fcd3c0ff /Documentation/i2c/busses
parent254df038e5ca275be437d5fa562d7f59beab6ef5 (diff)
downloadlinux-6bec23bff914915822f2c34d0555902fb2b9be1f.tar.xz
i2c: mlxcpld: add master driver for mellanox systems
Device driver for Mellanox I2C controller logic, implemented in Lattice CPLD device. Device supports: - Master mode - One physical bus - Polling mode The Kconfig currently controlling compilation of this code is: drivers/i2c/busses/Kconfig:config I2C_MLXCPLD Signed-off-by: Michael Shych <michaelsh@mellanox.com> Signed-off-by: Vadim Pasternak <vadimp@mellanox.com> Reviewed-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: Vladimir Zapolskiy <vz@mleia.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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+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:
+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.