From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <51D69197.7060802@ti.com>
Date: Fri, 5 Jul 2013 14:57:51 +0530
From: Sourav Poddar <sourav.poddar@ti.com>
MIME-Version: 1.0
To: yuhang wang <wangyuhang2014@gmail.com>
Subject: Re: SPI: DUAL/QUAD support
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Cc: linux-mtd <linux-mtd-bounces@lists.infradead.org>,
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On Friday 05 July 2013 02:47 PM, yuhang wang wrote:
> 2013/7/5 Sourav Poddar<sourav.poddar@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.