mpc52xx_psc.h

Why was the fifo struct separated from the psc struct for the 5200?

I see comments like this now:
        /* On the 5200, fifo regs are immediately adjacent to the psc regs */
        mps->fifo = ((void __iomem *)mps->psc) + sizeof(struct mpc52xx_psc);

Couldn't the fifo struct be a member at the end of the psc struct?

/* Structure of the hardware registers */
struct mpc52xx_psc {
	u8		mode;		/* PSC + 0x00 */
	u8		reserved0[3];
......
	u8		irmdr;		/* PSC + 0x50 */
	u8		reserved16[3];
	u8		irfdr;		/* PSC + 0x54 */
	u8		reserved17[3];
	struct mpc52xx_psc_fifo fifo; /* like this? */
};


-- 
Jon Smirl
jonsmirl@gmail.com

On Wed, Jun 11, 2008 at 3:05 PM, Jon Smirl [off-list ref] wrote:

Why was the fifo struct separated from the psc struct for the 5200?

I see comments like this now:
       /* On the 5200, fifo regs are immediately adjacent to the psc regs */
       mps->fifo = ((void __iomem *)mps->psc) + sizeof(struct mpc52xx_psc);

Couldn't the fifo struct be a member at the end of the psc struct?

The mpc5121 uses the same PSC register structure, but the fifo regs
are no longer adjacent.

Cheers,
g.

-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.