mirror of
https://github.com/torvalds/linux.git
synced 2024-11-19 10:31:48 +00:00
27aaa8ad5a
It adds capability register description to documentation. Signed-off-by: Michael Shych <michaelsh@mellanox.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
52 lines
1.6 KiB
Plaintext
52 lines
1.6 KiB
Plaintext
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.
|