openslx-ng/ipxe.git/src/drivers/bitbash/i2c_bit.c, branch v0.9.6

[i2c] Generalise i2c bit-bashing support to addressless devices

2008-10-01T18:24:56+00:00

Some devices (e.g. the Atmel AT24C11) have no concept of a device address; they respond to every device address and use this value as the word address. Some other devices use part of the device address field to extend the word address field. Generalise the i2c bit-bashing support to handle this by defining the device address length and word address length as properties of an i2c device. The word address is assumed to overflow into the device address field if the address used exceeds the width of the word address field. Also add a bus reset mechanism. i2c chips don't usually have a reset line, so rebooting the host will not clear any bizarre state that the chip may be in. We reset the bus by clocking SCL until we see SDA high, at which point we know we can generate a start condition and have it seen by all devices. We then generate a stop condition to leave the bus in a known state prior to use. Finally, add some extra debugging messages to i2c_bit.c.

Modify gPXE core and drivers to work with the new timer subsystem

2008-03-02T00:41:10+00:00

Signed-off-by: Alexey Zaytsev

Generalised the SPI abstraction layer to also be able to handle interfaces

2006-12-04T15:36:51+00:00

that don't provide the full flexibility of a bit-bashing interface. Temporarily hacked rtl8139.c to use the new interface.

We don't actually have a stdio.h header file. Our printf() functions are

2006-09-27T10:58:14+00:00

defined in vsprintf.h. (This may change, since vsprintf.h is a non-standard name, but for now it's the one to use.) There should be no need to include vsprintf.h just for DBG() statements, since include/compiler.h forces it in for a debug build anyway.

added stdio.h to includes for DBG compilation

2006-09-27T05:57:06+00:00

Move per-transition delays from generic bit-bashing layer to i2c layer

2006-06-14T00:20:35+00:00

(since SPI bit-bashing will require different delay semantics).

Change read_bit() to return 0 or -1UL, rather than 0 or 1.

2006-06-12T19:29:50+00:00

Added bit-bashing i2c interface code

2006-06-11T00:57:00+00:00