problem with register_hw_with_fixup

problem with register_hw_with_fixup

[Stefan Althoefer]

hi,

I'm currently developing a ide driver for an embedded ARM device.
The device hardware is somewhat wired, as all IDE access must
be done 16bit, even the control bytes. I therefore need special
access functions.

I do this to register special IN/OUT functions:

-----%<---some code delete for brevity-------------
void empca400_fixup(
     ide_hwif_t *hwif
)
{
     hwif->mmio = 2;
     hwif->OUTB = &empca400_ide_outb;
     hwif->OUTBSYNC = &empca400_ide_outbsync;
     hwif->OUTW = &empca400_ide_outw;
     hwif->OUTSW = &empca400_ide_outsw;
     :
}


static int __init empca400ide_init(void)
{
	:

         memset(&hw, 0, sizeof(hw));

         base = 0x56000000;
         aux  = base + 0x10;

         vbase = (unsigned long) ioremap(base, 0x10);
         vaux  = vbase + 0x20;

         for (i = IDE_DATA_OFFSET; i <= IDE_STATUS_OFFSET; i++) {
                 hw.io_ports[i] = (unsigned long)vbase;
                 vbase += 4;
         }
         hw.io_ports[IDE_CONTROL_OFFSET] = vaux + (6 * 0x2);
         hw.irq = 20;  /* GPIO3 = IRQ20 */
         hw.dma = NO_DMA;
         hw.chipset = ide_generic;

         ret = ide_register_hw_with_fixup(&hw, &hwif, empca400_fixup);

	:
}
-----------------------------------------------------

However, in probe_hwif_init_with_fixup() I find this sequence:

-----%<-----------------
int probe_hwif_init_with_fixup(ide_hwif_t *hwif, void (*fixup)(ide_hwif_t *hwif))
{
	probe_hwif(hwif);

	if (fixup)
		fixup(hwif);
-------------------------

fixup() gets called after probe_hwif, hence my special function
pointers will not be installed in time.

Shouldn't probe_hwif_init_with_fixup() call the fixup() first? If
not, what is fixup() good for, and how can I get my function
pointers registered before probe_hwif()?


mfg

-- 
----------------------
Stefan Althöfer (stefan.althoefer@janz.de)
Janz Automationssysteme AG
   - Automation Intelligence -
Member of the Janz company group
Im Doerener Feld 8
33100 Paderborn - Germany

Re: problem with register_hw_with_fixup

[Alan]

On Tue, 23 Jan 2007 09:51:52 +0100
Stefan Althoefer <as@janz.de> wrote:

> hi,
> 
> I'm currently developing a ide driver for an embedded ARM device.
> The device hardware is somewhat wired, as all IDE access must
> be done 16bit, even the control bytes. I therefore need special
> access functions.

For new drivers you should really be looking at drivers/ata

> However, in probe_hwif_init_with_fixup() I find this sequence:
> 
> -----%<-----------------
> int probe_hwif_init_with_fixup(ide_hwif_t *hwif, void (*fixup)(ide_hwif_t *hwif))
> {
> 	probe_hwif(hwif);
> 
> 	if (fixup)
> 		fixup(hwif);
> -------------------------
> 
> fixup() gets called after probe_hwif, hence my special function
> pointers will not be installed in time.

fixup is intended for doing drive level fixups and was added fairly
recently to deal with things like IT8212 in RAID mode and some PCMCIA
decode problems which run after the probe.

There isn't a good way to handle this with the old IDE layer. PMac does
it by walking the hwif array itself (without any proper locking). Adding
the call you need might be a good idea, but moving fixup will break
things.

Alan