Very Computer

by **Francisco Obisp** » Fri, 17 Mar 2000 04:00:00

Hello.... I have a problem with a driver that Im developing....

When I use outb_p(0x8f,0x300) (Write 0x8f to 0x300) it seems like it
does something but it......

Do I have to reserve this memory space for my card??? do I do this by
calling kmalloc??? How do I tell linux that my ISA card is going to use
0x300????

Thanx

by **Thomas Eschenbache** » Fri, 17 Mar 2000 04:00:00

> [...]
> When I use outb_p(0x8f,0x300) (Write 0x8f to 0x300) it seems like it
> does something but it......

you are addressing i/o space, not memory!

Quote:> Do I have to reserve this memory space for my card??? do I do this by
> calling kmalloc??? How do I tell linux that my ISA card is going to use
> 0x300????

so you should register your driver that it uses this i/o port range. For
an example, take a look at /usr/src/linux/drivers/rtc.c and search for
"request_region".

It is likely that you want to do something like this in your driver's
init function:

#define PORT 0x300
#define RANGE 8
#define NAME "my_driver"

if (check_region(PORT, RANGE) == -EBUSY) {
printk(NAME "i/o ports are in use!");
return -EBUSY;

Quote:}

request_region(PORT, RANGE, NAME);

... and somewhere in the close function:

release_region(PORT, RANGE);

bye,
Thomas.
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