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RE: Access to R_PORT_PB_DATA
You should use shadow variables for the registers to keep the old
value. Take a look in the gpio driver (arch/cris/drivers/gpio.c).
Also note that some of the PB pins are unavailable if you enable
certain interfaces (e.g. SCSI, USB, Sync serial).
Sent: 8/23/2001 3:24 PM
Subject: Access to R_PORT_PB_DATA
I'm trying to write a device driver that uses PB general I/O. In order
that, the driver accesses pins of the register R_PORT_PB_DATA (they are
to output) in the following ways:
What happens is that the system crashes. The same happens, when I'm
addressing the discrete general ports, too.
I'm using the development board with the ETRAX 100LX, Linux 2.4.5,
devboard_lx-R2_0_0 and cris compiler 1.13.
Does anyone know what's wrong about my code?