SPI: DUAL/QUAD support

[Sourav Poddar]

On Friday 05 July 2013 02:47 PM, yuhang wang wrote:
> 2013/7/5 Sourav Poddar<sourav.poddar at ti.com>:
>> On Friday 05 July 2013 02:37 PM, yuhang wang wrote:
>>>>                       if (!quad_mode)
>>>>                               dra7xxx_writel(qspi, qspi->cmd |
>>>> QSPI_RD_SNGL,
>>>>                                               QSPI_SPI_CMD_REG);
>>>>                       else
>>>>                               dra7xxx_writel(qspi, qspi->cmd |
>>>> QSPI_RD_QUAD,
>>>>                                               QSPI_SPI_CMD_REG);
>>>>                    .......
>>>>                   }
>>> So what do you based on to set variable quad_mode.
>> Best way should be to check for flash device id and manufacture data. Based
>> on which you
>> can decide whether your flash supports quad bits or not.
> Perhaps I did not said it clearly. Your flash supports quad and you
> set it into quad
> mode. But how can your controller driver notice that. In other word,
> In which way
> provide this information from flash to spi controller.
Perhaps, I understood you initial patch wrong. :(
Yes, this is little confusing, and I am trying to figure out that.
As of now, I have tested it with some extern variable, though
we need to see how it can be done cleanly.
I am trying to see if your patch can be used in some way now.