[i2c] [patch 2.6.23.1, version 4] add support for the PCF8575 chip

Jean Delvare khali at linux-fr.org
Sun Oct 28 12:19:37 CET 2007


Hi Bart,

On Fri, 26 Oct 2007 11:47:31 +0200, Bart Van Assche wrote:
> Regarding the sysfs interface: the sysfs interface for the pcf8575
> driver is consistent with that of the pcf8574 driver, so why do you
> call this interface strange ? Furthermore, you don't have to use the
> sysfs interface -- you can still call read() and write() from C/C++
> code on the device node corresponding with the chip you want to
> address.

You certainly do NOT want to do direct read() and write() on the i2c
device node while the pcf8574 driver or pcf8575 driver is loaded: that
would break the drivers's internal state. Use either a driver and it's
sysfs interface, or direct node access, NOT both.

-- 
Jean Delvare



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