On Saturday 12 January 2008, Sean MacLennan wrote:
> Josh Boyer wrote:
> >> + if (gpio_base == NULL) {
> >> + printk("ERROR: Unable to remap GPIO base.\n");
> >> + return;
> >> + }
> >> + }
> >> +
> >> + leds = readl(gpio_base + 0x100);
> >
> > Do you really want readl here? That will byte-swap.
>
> According to the docs I got from the hardware guys, this is correct.
> That does *not* mean they didn't get it wrong. Unfortunately, it was
> just on a piece of paper and I don't know if I still have it.
You are accessing the 440EP GPIO controller here right? Then you really should
use big endian access routines. From you code I assume that you have
connected the LED signals to GPIO00 and GPIO01. I suggest to use code that
looks like this:
#define LED_GREEN (0x80000000 >> 0)
#define LED_RED (0x80000000 >> 1)
leds = in_be32(gpio_base);
switch (green) {
case 0: leds &= ~LED_GREEN; break;
case 1: leds |= LED_GREEN; break;
}
switch (red) {
case 0: leds &= ~LED_RED; break;
case 1: leds |= LED_RED; break;
}
outbe32(leds, gpio_base);
And when you change the dts to describe both GPIO controllers you should map
the 2nd one and remove the 0x100 offset above as I have done above.
Best regards,
Stefan
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