RE: Can not get PATA to work for Compact Flash with 2.6.28 kernel

I redefined io functions in libata-sff.c, byte operations are converted
to 16bit word operations. Maybe I should ask for HW changes in new
revisions of the board.

These are the changes I had to make in drivers/ata/libata-sff.c.
TR5000V2 is my board config define.

#if defined(CONFIG_TR5000V2)

#define ioread8(X) ide_inb(X)
#define iowrite8(X, Y) ide_outb(X, Y)
#define ioread16_rep(X, Y, Z) ide_read16_rep(X, Y, Z)
#define iowrite16_rep(X, Y, Z) ide_write16_rep(X, Y, Z)

static void inline ide_outb (u8 val, void __iomem *addr)
{
   asm("eieio");
   *(ushort *)addr =3D val;
   asm("eieio");
   asm("sync");
}

static unsigned char inline ide_inb(void __iomem *addr)
{
   ushort data16;
   data16 =3D *(volatile ushort *)(addr);
   asm("eieio");=20
   asm("sync");
   return data16;
}


static void ide_read16_rep(void __iomem *addr, void *dst, unsigned long
ulcount)
{
   const volatile u16 __iomem *port =3D addr;
   void *buf =3D dst;
   long count =3D ulcount;
   u16 *tbuf =3D buf;
   u16 tmp;

   if (unlikely(count <=3D 0))
      return;
   asm volatile("sync");
   do {
      tmp =3D *port;
      eieio();
      *tbuf++ =3D tmp>>8 | tmp<<8;
   } while (--count !=3D 0);
   asm volatile("twi 0,%0,0; isync" : : "r" (tmp));
}

static void ide_write16_rep(void __iomem *addr, const void *src,
unsigned long ulcount)
{
   volatile u16 __iomem *port =3D addr;
   const void *buf =3D src;
   long count =3D ulcount;  =20
   const u16 *tbuf =3D buf;

   if (unlikely(count <=3D 0))
      return;
   asm volatile("sync");
   do {
      *port =3D *tbuf<<8 | *tbuf>>8;
      tbuf++;
   } while (--count !=3D 0);
   asm volatile("sync");
}
#endif=20


I can mount DOS FS now.

mknod /dev/sda1 b 8 1
mount -t msdos /dev/sda1 /mnt

Thanks.

Lixin

-----Original Message-----
From: Steven A. Falco [mailto:<redacted>]=20
Sent: Monday, February 02, 2009 4:52 PM
To: Lixin Yao
Cc: Aaron Pace; <redacted>
Subject: Re: Can not get PATA to work for Compact Flash with 2.6.28
kernel

Lixin Yao wrote:

Steven/Aaron,
=20
I found the problem. On my board, the CF is on a 16 bit interface on

bus

of MPC8248. The HW is connected in Big Endian format. PPC Bit D0 is
connected to CF Bit D15, and PPC D1 to CF Bit D14, till PPC D0 to CF
D15. I had to swap the bytes in u-boot. I forgot to do it in Kernel.=20
=20
After making the change, CF is detected. But I can not access /dev/hda
or any scsi/sda devices under /dev.=20
=20

How did you swap the bytes?  The CF will be accessed both in byte mode
and in 16-bit mode.  So this is tricky to do in software.  When we
wired our CF, we deliberately swapped the bytes in hardware.  So the
processor bus MSB goes to pin 6 of the CF.

	Steve