From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <51D68D14.7090606@ti.com>
Date: Fri, 5 Jul 2013 14:38:36 +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>,
 Johannes Stezenbach <js@sig21.net>, Grant Likely <grant.likely@secretlab.ca>,
 Mark Brown <broonie@kernel.org>, linux-mtd@lists.infradead.org,
 Thomas.Betker@rohde-schwarz.com, spi-devel-general@lists.sourceforge.net,
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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.