From: Yao Yuan <yao.yuan@nxp.com>
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-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: AQHR+SUcXttcwTcokUqMoukEQMDIX6B5j7MAgAC5BYCAYh3JAIAA85QAgAADr5CAABeQgIABPAmA
Date: Fri, 18 Nov 2016 04:19:53 +0000
Message-ID: <DB6PR0401MB24074D231C8EBCC56E168CC989B00@DB6PR0401MB2407.eurprd04.prod.outlook.com>
References: <1471505884-33996-1-git-send-email-B56489@freescale.com>
 <1471505884-33996-6-git-send-email-B56489@freescale.com>
 <CA+EcR20NkBzFjMJ_ArWw9ALZY-x1SqwS1nUyGYAnjsygTk8K-Q@mail.gmail.com>
 <AM4PR0701MB21308B262DB7B94E0F7FC34EFEF00@AM4PR0701MB2130.eurprd07.prod.outlook.com>
 <20161116171058.GA21300@Cayman.am.freescale.net>
 <AM4PR0701MB2130273C90BE0EE615382718FEB10@AM4PR0701MB2130.eurprd07.prod.outlook.com>
 <DB6PR0401MB24077A46D3FC5147DC4C69D989B10@DB6PR0401MB2407.eurprd04.prod.outlook.com>
 <AM4PR0701MB213027FC738E6E377A593B60FEB10@AM4PR0701MB2130.eurprd07.prod.outlook.com>
In-Reply-To: <AM4PR0701MB213027FC738E6E377A593B60FEB10@AM4PR0701MB2130.eurprd07.prod.outlook.com>
Accept-Language: en-US, zh-CN
Content-Language: en-US
spamdiagnosticoutput: 1:99
spamdiagnosticmetadata: NSPM
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-originalarrivaltime: 18 Nov 2016 04:19:53.8042
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DB6PR0401MB2406
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Transfer-Encoding: 8bit
X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id uAIGtpgl020191
Content-Length: 8668
Lines: 218

On Thu, Nov 17, 2016 at 10:14:55AM +0000, Krzeminski, Marcin (Nokia - PL/Wroclaw) wrote:
> > 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,

Hi Krzeminski,

Get it.
So do you think how about that I add a flag in dts to select it?
The user want's disable 4kb, he can add the flag.

In spi-nor.c:
if (of_property_read_bool(np, "spi-nor, disable-4kb")) {
	spansion_s25fs_disable_4kb_erase();
}
                else
...

In dts:

&qspi {
        num-cs = <2>;
        bus-num = <0>;
        status = "okay";

        qflash0: s25fs512s@0 {
                compatible = "spansion, s25fs512s";
	 spi-nor, disable-4kb
                #address-cells = <1>;
                #size-cells = <1>;
                spi-max-frequency = <20000000>;
                reg = <0>;
        };

I think it should be a better way.

How about your think?

Thanks.