[U-Boot] [PATCH 2/5] NetStar: Fix NAND

Scott Wood
2009-03-17T17:17:30Z

On Mon, Mar 16, 2009 at 11:28:24PM +0100, Ladislav Michl wrote:
> Fix NAND support broken during new NAND code merge. Move those few lines of
> code to board/netstar/netstar.c

What was the breakage?

> -/*
> - * hardware specific access to control-lines
> - */
> -#define MASK_CLE 0x02
> -#define MASK_ALE 0x04
> -
> -static void netstar_nand_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int ctrl)
> -{
> - struct nand_chip *this = mtd->priv;
> - ulong IO_ADDR_W = (ulong) this->IO_ADDR_W;
> -
> - IO_ADDR_W &= ~(MASK_ALE|MASK_CLE);
> - if (ctrl & NAND_CTRL_CHANGE) {
> - if ( ctrl & NAND_CLE )
> - IO_ADDR_W |= MASK_CLE;
> - if ( ctrl & NAND_ALE )
> - IO_ADDR_W |= MASK_ALE;
> - }
> - this->IO_ADDR_W = (void __iomem *) IO_ADDR_W;
> -
> - if (cmd != NAND_CMD_NONE)
> - writeb(cmd, this->IO_ADDR_W);
> -}
[snip]
> +#if defined(CONFIG_CMD_NAND)
> +/*
> + * hardware specific access to control-lines
> + *
> + * NAND_NCE: bit 0 - don't care
> + * NAND_CLE: bit 1 -> bit 1 (0x0002)
> + * NAND_ALE: bit 2 -> bit 2 (0x0004)
> + */
> +static void netstar_nand_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int ctrl)
> +{
> + struct nand_chip *chip = mtd->priv;
> + unsigned long mask;
> +
> + if (cmd == NAND_CMD_NONE)
> + return;
> +
> + mask = (ctrl & NAND_CLE) ? 0x02 : 0;
> + if (ctrl & NAND_ALE)
> + mask |= 0x04;
> + writeb(cmd, (unsigned long)chip->IO_ADDR_W | mask);
> +}

Do not pass integers as addresses.

The new function looks functionally identical to the old one (except that
it ignores the interface in a couple of ways that it didn't before, but
which don't really matter). Why the change? Why the difference between
CLE using ?: and ALE using an if-statement?

-Scott