[U-Boot] [PATCH 4/7] mxc_nand: add nand driver for MX2/MX3

[Magnus Lilja]

Hi

2009/6/23 Scott Wood <scottwood at freescale.com>:
> On Mon, Jun 08, 2009 at 04:12:48AM +0400, Ilya Yanok wrote:
>> Driver for NFC NAND controller found on Freescale's MX2 and MX3
>> processors. Ported from Linux. Tested only with i.MX27 but should
>> works with other MX2 and MX3 processors too.
>>
>> Signed-off-by: Ilya Yanok <yanok at emcraft.com>
>> +static u_char mxc_nand_read_byte(struct mtd_info *mtd)
>> +{
>> +     struct nand_chip *nand_chip = mtd->priv;
>> +     struct mxc_nand_host *host = nand_chip->priv;
>> +     uint8_t ret = 0;
>> +     uint16_t col, rd_word;
>> +     uint16_t __iomem *main_buf =
>> +             (uint16_t __iomem *)host->regs->main_area0;
>> +     uint16_t __iomem *spare_buf =
>> +             (uint16_t __iomem *)host->regs->spare_area0;
>
> According to Magnus Lilja, "the nand flash controller can only handle 32
> bit read/write operations, any other size will cause an abort (or
> something like that)".  But now we're accessing it as 16-bit?

I'm not sure if the controller allows 16 bit accesses or not, don't
remember if I've tried that. 8 bit accesses don't work. Also, I don't
know if it's the controller itself that can't cope with 8 bit accesses
or if it's the bus interface to the NFC block in i.MX31.

Regards, Magnus