From: "Krzeminski, Marcin (Nokia - PL/Wroclaw)" 
        <marcin.krzeminski@nokia.com>
To: Yao Yuan <yao.yuan@nxp.com>, Han Xu <xhnjupt@gmail.com>
CC: David Woodhouse <dwmw2@infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-mtd@lists.infradead.org" <linux-mtd@lists.infradead.org>,
        "han.xu@freescale.com" <han.xu@freescale.com>,
        Brian Norris <computersforpeace@gmail.com>,
        "jagannadh.teki@gmail.com" <jagannadh.teki@gmail.com>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>
Subject: RE: [PATCH v3 6/9] mtd: spi-nor: Support R/W for S25FS-S family flash
Thread-Topic: [PATCH v3 6/9] mtd: spi-nor: Support R/W for S25FS-S family
 flash
Thread-Index: AQHSDsFtxMlOkvvut0S5VzdgW9CbSaB6GISggGIixQCAAOiacIAAJJCAgAAAiTA=
Date: Thu, 17 Nov 2016 09:20:17 +0000
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> -----Original Message-----
> From: Yao Yuan [mailto:yao.yuan@nxp.com]
> Sent: Thursday, November 17, 2016 10:14 AM
> To: Krzeminski, Marcin (Nokia - PL/Wroclaw)
> <marcin.krzeminski@nokia.com>; Han Xu <xhnjupt@gmail.com>
> Cc: David Woodhouse <dwmw2@infradead.org>; linux-
> kernel@vger.kernel.org; linux-mtd@lists.infradead.org;
> han.xu@freescale.com; Brian Norris <computersforpeace@gmail.com>;
> jagannadh.teki@gmail.com; linux-arm-kernel@lists.infradead.org
> Subject: RE: [PATCH v3 6/9] mtd: spi-nor: Support R/W for S25FS-S family
> flash
> 
> On Thu, Nov 17, 2016 at 06:50:55AM +0000, Krzeminski, Marcin (Nokia -
> PL/Wroclaw) wrote:
> > > > > On Thu, Aug 18, 2016 at 2:38 AM, Yunhui Cui
> > > > > <B56489@freescale.com>
> > > > > wrote:
> > > > > > From: Yunhui Cui <yunhui.cui@nxp.com>
> > > > > >
> > > > > > With the physical sectors combination, S25FS-S family flash
> > > > > > requires some special operations for read/write functions.
> > > > > >
> > > > > > Signed-off-by: Yunhui Cui <yunhui.cui@nxp.com>
> > > > > > ---
> > > > > >  drivers/mtd/spi-nor/spi-nor.c | 56
> > > > > > +++++++++++++++++++++++++++++++++++++++++++
> > > > > >  1 file changed, 56 insertions(+)
> > > > > >
> > > > > > diff --git a/drivers/mtd/spi-nor/spi-nor.c
> > > > > > b/drivers/mtd/spi-nor/spi-nor.c index d0fc165..495d0bb 100644
> > > > > > --- a/drivers/mtd/spi-nor/spi-nor.c
> > > > > > +++ b/drivers/mtd/spi-nor/spi-nor.c
> > > > > > @@ -39,6 +39,10 @@
> > > > > >
> > > > > >  #define SPI_NOR_MAX_ID_LEN     6
> > > > > >  #define SPI_NOR_MAX_ADDR_WIDTH 4
> > > > > > +/* Added for S25FS-S family flash */
> > > > > > +#define SPINOR_CONFIG_REG3_OFFSET      0x800004
> > > > > > +#define CR3V_4KB_ERASE_UNABLE  0x8 #define
> > > > > > +SPINOR_S25FS_FAMILY_EXT_JEDEC  0x81
> > > > > >
> > > > > >  struct flash_info {
> > > > > >         char            *name;
> > > > > > @@ -78,6 +82,7 @@ struct flash_info {  };
> > > > > >
> > > > > >  #define JEDEC_MFR(info)        ((info)->id[0])
> > > > > > +#define EXT_JEDEC(info)        ((info)->id[5])
> > > > > >
> > > > > >  static const struct flash_info *spi_nor_match_id(const char
> > > > > > *name);
> > > > > >
> > > > > > @@ -899,6 +904,7 @@ static const struct flash_info spi_nor_ids[] = {
> > > > > >          */
> > > > > >         { "s25sl032p",  INFO(0x010215, 0x4d00,  64 * 1024,
> > > > > > 64,
> > > > > SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
> > > > > >         { "s25sl064p",  INFO(0x010216, 0x4d00,  64 * 1024,
> > > > > > 128, SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
> > > > > > +       { "s25fs256s1", INFO6(0x010219, 0x4d0181, 64 * 1024,
> > > > > > + 512, 0)},
> > > > > >         { "s25fl256s0", INFO(0x010219, 0x4d00, 256 * 1024, 128, 0) },
> > > > > >         { "s25fl256s1", INFO(0x010219, 0x4d01,  64 * 1024,
> > > > > > 512,
> > > > > SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
> > > > > >         { "s25fl512s",  INFO(0x010220, 0x4d00, 256 * 1024,
> > > > > > 256, SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) }, @@ -1036,6
> > > +1042,50
> > > > > @@ static const struct flash_info *spi_nor_read_id(struct
> > > > > spi_nor
> > > > > *nor)
> > > > > >         return ERR_PTR(-ENODEV);  }
> > > > > >
> > > > > > +/*
> > > > > > + * The S25FS-S family physical sectors may be configured as a
> > > > > > + * hybrid combination of eight 4-kB parameter sectors
> > > > > > + * at the top or bottom of the address space with all
> > > > > > + * but one of the remaining sectors being uniform size.
> > > > > > + * The Parameter Sector Erase commands (20h or 21h) must
> > > > > > + * be used to erase the 4-kB parameter sectors individually.
> > > > > > + * The Sector (uniform sector) Erase commands (D8h or DCh)
> > > > > > + * must be used to erase any of the remaining
> > > > > > + * sectors, including the portion of highest or lowest
> > > > > > +address
> > > > > > + * sector that is not overlaid by the parameter sectors.
> > > > > > + * The uniform sector erase command has no effect on
> > > > > > +parameter
> > > > > sectors.
> > > > > > + */
> > > > > > +static int spansion_s25fs_disable_4kb_erase(struct spi_nor *nor) {
> > > > > > +       u32 cr3v_addr  = SPINOR_CONFIG_REG3_OFFSET;
> > > > > > +       u8 cr3v = 0x0;
> > > > > > +       int ret = 0x0;
> > > > > > +
> > > > > > +       nor->cmd_buf[2] = cr3v_addr >> 16;
> > > > > > +       nor->cmd_buf[1] = cr3v_addr >> 8;
> > > > > > +       nor->cmd_buf[0] = cr3v_addr >> 0;
> > > > > > +
> > > > > > +       ret = nor->read_reg(nor, SPINOR_OP_SPANSION_RDAR,
> &cr3v, 1);
> > > > > > +       if (ret)
> > > > > > +               return ret;
> > > > > > +       if (cr3v & CR3V_4KB_ERASE_UNABLE)
> > > > > > +               return 0;
> > > > > > +       ret = nor->write_reg(nor, SPINOR_OP_WREN, NULL, 0);
> > > > > > +       if (ret)
> > > > > > +               return ret;
> > > > > > +       cr3v = CR3V_4KB_ERASE_UNABLE;
> > > > > > +       nor->program_opcode = SPINOR_OP_SPANSION_WRAR;
> > > > > > +       nor->write(nor, cr3v_addr, 1, &cr3v);
> > > > > > +
> > > > > > +       ret = nor->read_reg(nor, SPINOR_OP_SPANSION_RDAR,
> &cr3v, 1);
> > > > > > +       if (ret)
> > > > > > +               return ret;
> > > > > > +       if (!(cr3v & CR3V_4KB_ERASE_UNABLE))
> > > > > > +               return -EPERM;
> > > > > > +
> > > > > > +       return 0;
> > > > > > +}
> > > > > > +
> > > > > >  static int spi_nor_read(struct mtd_info *mtd, loff_t from, size_t
> len,
> > > > > >                         size_t *retlen, u_char *buf)  { @@
> > > > > > -1361,6
> > > > > > +1411,12 @@ int spi_nor_scan(struct spi_nor *nor, const char
> > > > > > +*name,
> > > > > enum read_mode mode)
> > > > > >                 spi_nor_wait_till_ready(nor);
> > > > > >         }
> > > > > >
> > > > > > +       if (EXT_JEDEC(info) == SPINOR_S25FS_FAMILY_EXT_JEDEC) {
> > > > > > +               ret = spansion_s25fs_disable_4kb_erase(nor);
> > > > > > +               if (ret)
> > > > > > +                       return ret;
> > > > > > +       }
> > > > > > +
> > > > > >         if (!mtd->name)
> > > > > >                 mtd->name = dev_name(dev);
> > > > > >         mtd->priv = nor;
> > > > > > --
> > > > > > 2.1.0.27.g96db324
> > > > > >
> > > > > >
> > > > > Hi Brian, I will ack this change but still feel it's kind of hacking code.
> > > > >
> > > > > Acked-by: Han xu <han.xu@nxp.com>
> > > >
> > > > I am new on the list so I am not sure if this topic has been discussed.
> > > > Generally our product functionality relay on those 4KiB sectors.
> > > > I know that this hack is already in u-boot, but if you mainstream
> > > > this you will force users of those 4KiB sectors to do hack the hack...
> > > > I believe the proper solution here is to use erase regions
> > > > functionality, I send and RFS about that some time ago.
> > >
> > > Do you mind to send me a link for reference?
> > >
> > Han,
> >
> > Sorry, It seem I have not posted erase region changes (only those
> > regarding DUAL/QUAD I/O).
> > Generally, in this flash you need to create 3 erase regions (because
> > in FS-S family support only  4KiB erase on parameters sector - eg. 1.2.2.4 in
> S25FS512S).
> > In my case regions are:
> > 1. 0-32KiB (8*4KiB) - 4K_ERASE (0x20/0x21) 2. 32 - 256 - SE_CMD
> (0xd8/0xdc) 3.
> > Rest of the flash SE_CMD (0xd8/0xdc)
> >
> > To erase whole flash you can also use CHIP_ERASE_CMD (0x60/0xC7)
> > command, you just need to add one more mtd partition that will cover
> whole flash.
> >
> 
> Hi Krzeminski,
> 
> Do you think is there any great advantages for enable 4KB?
> Because for NXP(Freescale) QSPI controller, there is only support max to 16
> groups command.
> 
> So It's hard to give 3 groups command just for erase (0x21,0xdc and 0xc7).
> So we have to disable the 4kb erase and only use 256kbytes in this patch.
> 
Yes, if you disable parameters sector in spi-nor framework you will disable it
for all spi-nor clients not only for NXP QSPI controller. There are users (at
least me) that relay on parameters sector functionality. This patch will brake it.

Thanks,
Marcin