Registers
| NAME
|
ADDRESS
|
WIDTH
|
| REG_I2CDATA
|
0x04004500
|
1
|
| REG_I2CCNT
|
0x04004501
|
1
|
REG_I2CDATA
| BIT
|
DESCRIPTION
|
| 0
|
R/W, clear for write, set for read
|
| 1
|
Start/device select bit?
|
| 2
|
Restart/device reselect bit?
|
| 3
|
?
|
| 4
|
SCL hold. When clear SCL is being held low, set when SCL is high. This bit must always be set(by reading CNT again) after writing REG_I2CCNT. This bit must be set when writing blocks of data(more than 1 byte) with bit0 clear.
|
| 5
|
SCL, toggle this for each loop iteration(in the loop execute the I2C WR code) with max 8 iterations where the loop exits successfully when bit 4 is set. This bit must be set when writing blocks of data(more than 1 byte) with bit0 clear.
|
| 6
|
Unknown, always set when writing to CNT?
|
| 7
|
Enable/busy, wait for this bit to clear after writing to I2CCNT.
|
Protocol
Wait for the busy bit to clear. Write the device address to REG_I2CDATA, then write 0xc2(busy/enable, bit 6, and start bit 1 set) to REG_I2CCNT. Execute swiWaitByLoop for a device-specific duration, then write the register address to REG_I2CDATA, and write 0xc0 to REG_I2CCNT.(busy/enable and bit 6 set) Wait with swiWaitByLoop device duration, then write the data to REG_I2CDATA when writing. When reading, write the device address to REG_I2CDATA and write 0xc2 to REG_I2CCNT. When the delay value is zero, write 0xc1 | i<<5 to REG_I2CCNT, otherwise write 0xc0 | i<<5 to REG_I2CCNT, wait for busy to clear, delay, then write 0xc5 to REG_I2CCNT. For writing i is the loop i for iteration, for reading replace that with 1. When reading, read the data from REG_I2CCNT. Return a error if REG_I2CCNT bit 4 SCL hold is set, otherwise return normal.
I2C devices
I2C device table:
| Device address
|
Device swiWaitByLoop delay
|
Device description
|
| 0x00
|
0x00
|
Camera0?
|
| 0x80
|
0x00
|
Camera1?
|
| 0x00
|
0x00
|
?
|
| 0x00
|
0x00
|
?
|
| 0x7A
|
0x180
|
Power management
|
| 0x78
|
0x00
|
?
|
| 0xA0
|
0x00
|
?
|
| 0x4A
|
?
|
Power related?
|
| 0x4B
|
?
|
Power related?
|
Power management
When registers 0x70 and 0x11 are set to 1 in that order, a power cycle is done.
| REGISTER
|
WIDTH
|
DESCRIPTION
|
| 0x11
|
1
|
System reset register 2.
|
| 0x12
|
1
|
Might be MMC bus power related, unknown.
|
| 0x31
|
1
|
Cameras' power? Value 0 turns off power to cameras? Values 1/2 activates a camera's power?
|
| 0x70
|
1
|
System reset register 1.
|