[U-Boot] [PATCH] tegra: nand: make ONFI detection work

[Scott Wood <scottwood@freescale.com>]

On 09/28/2012 10:56:51 AM, Lucas Stach wrote:
> Add the missing bits to the Tegra NAND driver to make ONFI detection  
> work
> properly.
> 
> Also add it to the Tegra default config, as it seems to be a  
> reasonable thing
> to have it available on all boards that use any kind of NAND.
> 
> Signed-off-by: Lucas Stach <dev@lynxeye.de>
> ---
>  drivers/mtd/nand/tegra_nand.c    | 36  
> ++++++++++++++++++++++++++++++++++++
>  include/configs/tegra20-common.h |  1 +
>  2 Dateien ge?ndert, 37 Zeilen hinzugef?gt(+)
> 
> diff --git a/drivers/mtd/nand/tegra_nand.c  
> b/drivers/mtd/nand/tegra_nand.c
> index 2c1b533..0d7ca5d 100644
> --- a/drivers/mtd/nand/tegra_nand.c
> +++ b/drivers/mtd/nand/tegra_nand.c
> @@ -219,6 +219,34 @@ static uint8_t read_byte(struct mtd_info *mtd)
>  }
> 
>  /**
> + * Read len bytes from the chip into a buffer
> + *
> + * @param mtd	MTD device structure
> + * @param buf	buffer to store data to
> + * @param len	number of bytes to read
> + *
> + * Read function for 8bit bus-width
> + */
> +static void read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
> +{
> +	int i, s;
> +	unsigned int reg;
> +	struct nand_chip *chip = mtd->priv;
> +	struct nand_drv *info = (struct nand_drv *)chip->priv;
> +
> +	for (i = 0; i < len; i += 4) {
> +		s = (len - i) > 4 ? 4 : len - i;
> +		writel(CMD_PIO | CMD_RX | CMD_A_VALID | CMD_CE0 |
> +			((s - 1) << CMD_TRANS_SIZE_SHIFT) | CMD_GO,
> +			&info->reg->command);
> +		if (!nand_waitfor_cmd_completion(info->reg))
> +			printf("Command timeout during read_buf\n");
> +		reg = readl(&info->reg->resp);
> +		memcpy(buf + i, &reg, s);
> +	}
> +}

Out of curiousity, what is it about this that needed a custom  
read_buf() where you didn't need one before?

-Scott