lkml.org 
[lkml]   [2014]   [Sep]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRe: [PATCH 1/1 v2] driver:mtd:spi-nor: Add Micron quad I/O support
    Date
    On Sunday, September 28, 2014 at 03:59:42 AM, bpqw wrote:
    > For Micron spi norflash,you can enable
    > Quad spi transfer by clear EVCR(Enhanced
    > Volatile Configuration Register) Quad I/O
    > protocol bit.

    OK, this information is nice and all, but what does this patch do? I can't learn
    this information from the commit message as it is, can I ? And , the purpose of
    the commit message is exactly to summarize the change the patch implements.

    > Signed-off-by: bean huo <beanhuo@micron.com>
    > ---
    > v1-v2:modified to that capture wait_till_ready()
    > return value,if error,directly return its
    > the value.
    >
    > drivers/mtd/spi-nor/spi-nor.c | 46
    > +++++++++++++++++++++++++++++++++++++++++ include/linux/mtd/spi-nor.h |
    > 6 ++++++
    > 2 files changed, 52 insertions(+)
    >
    > diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
    > index b5ad6be..0c3b4fd 100644
    > --- a/drivers/mtd/spi-nor/spi-nor.c
    > +++ b/drivers/mtd/spi-nor/spi-nor.c
    > @@ -878,6 +878,45 @@ static int spansion_quad_enable(struct spi_nor *nor)
    > return 0;
    > }
    >
    > +static int micron_quad_enable(struct spi_nor *nor)
    > +{
    > + int ret, val;
    > +
    > + ret = nor->read_reg(nor, SPINOR_OP_RD_EVCR, &val, 1);
    > + if (ret < 0) {
    > + dev_err(nor->dev, "error %d reading EVCR\n", ret);
    > + return -EINVAL;
    > + }
    > +
    > + write_enable(nor);
    > +
    > + /* set EVCR ,enable quad I/O */
    > + nor->cmd_buf[0] = val & ~EVCR_QUAD_EN_MICRON;
    > + ret = nor->write_reg(nor, SPINOR_OP_WD_EVCR, nor->cmd_buf, 1, 0);
    > + if (ret < 0) {
    > + dev_err(nor->dev,
    > + "error while writing EVCR register\n");
    > + return -EINVAL;

    Why not just "return ret;" ?
    [...]


    \
     
     \ /
      Last update: 2014-09-29 01:21    [W:4.089 / U:0.036 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site