[ts-7000] Re: TS-7400 DIO from kernel space

["basement_mobile2004" <>]

Hi Alexander,

   Digging books and tutorials I finally did it.
   0x1200_0000 is a reserved memory space and can't be accessed
directly. We have to remap that region to a random memory space area
via kernel functions to do so. I'll post the snippet of the code to do
that below:

#define GPIOCR 0x12000000UL

function()
{
        unsigned long gpiocr = 0, gpiocr1, gpiocr2, gpiocr3;

        volatile char *ptr;

        printk("DUMB: modulo adicionando\n");

        if(check_mem_region(GPIOCR, 4)) {
                printk("DUMB: espaco de memoria em uso: GPIOCR\n");
                return -EBUSY;
        }

        request_mem_region(GPIOCR, 4, "dumb_driver");
        ptr = __ioremap(GPIOCR, 4, 0);

        printk("dumb: ptr remap = %p\n", ptr);

#define GPIOCREG0       ((volatile char *)(ptr))
#define GPIOCREG1       ((volatile char *)(ptr+1))
#define GPIOCREG2       ((volatile char *)(ptr+2))
#define GPIOCREG3       ((volatile char *)(ptr+3))

        gpiocr = readb(GPIOCREG0);
        gpiocr1 = readb(GPIOCREG1);
        gpiocr2 = readb(GPIOCREG2);
        gpiocr3 = readb(GPIOCREG3);
        release_mem_region(GPIOCR, 4);
        printk("DUMB: lido CR 0x%lx 0x%lx 0x%lx 0x%lx\n", gpiocr,
gpiocr1, gpiocr2, gpiocr3);
...
}

       Hope that helps you.




--- In  Alexander Clouter <> wrote:
>
> Hi,
> 
> basement_mobile2004 <> [20080313 13:41:06 -0000]:
> >
> > I'm trying to access DIO registers from kernel space but it
> > redirects the address to upper addresses.
> >
> > [snipped]
> > 
> > Result:
> > Unable to handle kernel paging request at virtual address 72000000
> > pgd = c511c000
> > [72000000] *pgd=00000000, *pmd = 00000000
> >
> don't get excited, I'm curious about the answer to this too.  I have
no idea 
> about physical and virtual memory; however I would have expected the
macros
> __phys_to_virt() and __virt_to_phys() to have helped me.
> 
> Once I know this secret, the regular rtc-m48t86.c driver in the
linux kernel 
> will work along with (hopefully) the orion_nand.c MTD driver.
> 
> A plea to the Clued(tm) out there....pointers please.  :)
> 
> Cheers
> 
> Alex
> 
> -- 
>  ________________________________________
> / To err is human. To blame someone else \
> \ for your mistakes is even more human.  /
>  ----------------------------------------
>         \   ^__^
>          \  (oo)\_______
>             (__)\       )\/\
>                 ||----w |
>                 ||     ||
>



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