Re: arm: how to operate leds on zaurus?

[Russell King <rmk+lkml@arm.linux.org.uk>]

On Mon, Jul 11, 2005 at 09:34:54PM +0200, Pavel Machek wrote:
> Hi!
> 
> 2.6.12-rc5 (and newer) does not boot on sharp zaurus sl-5500. It
> blinks with green led, fast; what does it mean? I'd like to verify if
> it at least reaches .c code in setup.c. I inserted this code at
> begining of setup.c:674...
> 
> #define locomo_writel(val,addr) ({ *(volatile u16 *)(addr) = (val); })
> #define LOCOMO_LPT_TOFH         0x80
> #define LOCOMO_LED              0xe8
> #define LOCOMO_LPT0             0x00
> 
>       locomo_writel(LOCOMO_LPT_TOFH, LOCOMO_LPT0 + LOCOMO_LED);
> 
> ...but that does not seem to do a trick -- it only breaks the boot :-(

Basically because you do not have access to IO during the early boot.
The easiest debugging solution is to enable CONFIG_DEBUG_LL and
throw a printascii(printk_buf) into printk.c, after vscnprintf.
That might get you some boot messages through the serial port (if
it's implemented it correctly.)

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:  2.6 Serial core