> -----Original Message-----
> From: Brian Norris [mailto:computersforpe...@gmail.com]
> Sent: Wednesday, April 16, 2014 2:48 PM
> To: Hou Zhiqiang-B48286
> Cc: linux-...@lists.infradead.org; linuxppc-...@ozlabs.org; Wood Scott-
> B07421; Hu Mingkai-B21284; dw...@infradead.org
> Subject: Re: [PATCH] mtd: m25p80: Modify the name of mtd_info
>
> On Fri, Mar 21, 2014 at 07:16:18PM +0800, Hou Zhiqiang wrote:
> > To specify spi flash layouts by "mtdparts=..." in cmdline, we must
> > give mtd_info a fixed name,because the cmdlinepart's parser will match
> > the name of mtd_info given in cmdline.
> > Now, if use DT, the mtd_info's name will be spi->dev->name. It
> > consists of spi_master->bus_num, and the spi_master->bus_num maybe
> > dynamically fetched. So, in this case, replace the component bus_num
> > with thei physical address of spi master.
> >
> > Signed-off-by: Hou Zhiqiang <b48...@freescale.com>
> > ---
> > drivers/mtd/devices/m25p80.c | 18 +++++++++++++++---
> > 1 file changed, 15 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/mtd/devices/m25p80.c
> > b/drivers/mtd/devices/m25p80.c index 7eda71d..64450a2 100644
> > --- a/drivers/mtd/devices/m25p80.c
> > +++ b/drivers/mtd/devices/m25p80.c
> > @@ -30,6 +30,7 @@
> > #include <linux/mtd/cfi.h>
> > #include <linux/mtd/mtd.h>
> > #include <linux/mtd/partitions.h>
> > +#include <linux/of_address.h>
> > #include <linux/of_platform.h>
> >
> > #include <linux/spi/spi.h>
> > @@ -934,9 +935,11 @@ static int m25p_probe(struct spi_device *spi)
> > struct flash_platform_data *data;
> > struct m25p *flash;
> > struct flash_info *info;
> > - unsigned i;
> > + unsigned i, ret;
> > struct mtd_part_parser_data ppdata;
> > struct device_node *np = spi->dev.of_node;
> > + struct resource res;
> > + struct device_node *mnp = spi->master->dev.of_node;
> >
> > /* Platform data helps sort out which chip type we have, as
> > * well as how this board partitions it. If we don't have @@
> > -1009,8 +1012,17 @@ static int m25p_probe(struct spi_device *spi)
> >
> > if (data && data->name)
> > flash->mtd.name = data->name;
> > - else
> > - flash->mtd.name = dev_name(&spi->dev);
> > + else{
> > + ret = of_address_to_resource(mnp, 0, &res);
>
> You're making a lot assumptions about the SPI master/device relationship
> -- that the master has a device-node; that the first resource of the
> master is its physical address (this is not guaranteed by DT semantics).
> Please do not do this.
Thank you for your tips, but I think it is right to get the physical address
of master using the API of_address_to_resource, because of_address_to_resource
just parse address-resource from device tree.
>
> > + if (ret) {
> > + dev_err(&spi->dev, "failed to get spi master
> resource\n");
> > + return ret;
>
> This is wrong. It breaks all !CONFIG_OF cases which didn't specify a name
> via platform data.
>
I will resend a patch to fix it.
> > + }
> > + flash->mtd.name = kasprintf(GFP_KERNEL, "spi%x.%d",
> > + (unsigned)res.start, spi->chip_select);
> > + if (!flash->mtd.name)
> > + return -ENOMEM;
> > + }
> >
> > flash->mtd.type = MTD_NORFLASH;
> > flash->mtd.writesize = 1;
>
> Brian
>
Thanks,
Zhiqiang
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