[U-Boot] [PATCH v2 5/5] sifive: fu540: Enable spi-nor flash support

Bin Meng bmeng.cn at gmail.com
Mon Nov 18 02:49:05 UTC 2019


Hi Segar Kadam,

On Mon, Nov 18, 2019 at 4:59 AM Sagar Kadam <sagar.kadam at sifive.com> wrote:
>
>
> Hello Jagan/Bin,
>
> > -----Original Message-----
> > From: U-Boot <u-boot-bounces at lists.denx.de> On Behalf Of Bin Meng
> > Sent: Monday, November 11, 2019 8:02 PM
> > To: Jagan Teki <jagan at amarulasolutions.com>
> > Cc: Palmer Dabbelt ( Sifive) <palmer at sifive.com>; U-Boot Mailing List <u-
> > boot at lists.denx.de>; linux-amarula <linux-amarula at amarulasolutions.com>
> > Subject: Re: [U-Boot] [PATCH v2 5/5] sifive: fu540: Enable spi-nor flash
> > support
> >
> > Hi Jagan,
> >
> > On Sat, Nov 9, 2019 at 7:57 PM Jagan Teki <jagan at amarulasolutions.com>
> > wrote:
> > >
> > > Hi Bin,
> > >
> > > On Tue, Oct 29, 2019 at 3:50 PM Bin Meng <bmeng.cn at gmail.com> wrote:
> > > >
> > > > Hi Jagan,
> > > >
> > > > On Tue, Oct 29, 2019 at 5:38 PM Bin Meng <bmeng.cn at gmail.com>
> > wrote:
> > > > >
> > > > > Hi Jagan,
> > > > >
> > > > > On Wed, Oct 16, 2019 at 10:58 PM Jagan Teki
> > <jagan at amarulasolutions.com> wrote:
> > > > > >
> > > > > > HiFive Unleashed A00 support is25wp256 spi-nor flash,
> > > > > > So enable the same and add test result log for future
> > > > > > reference.
> > > > > >
> > > > > > Tested on SiFive FU540 board.
> > > > > >
> > > > > > Signed-off-by: Jagan Teki <jagan at amarulasolutions.com>
> > > > > > Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
> > > > > > Tested-by: Bin Meng <bmeng.cn at gmail.com>
> > > > > > ---
> > > > > >  .../dts/hifive-unleashed-a00-u-boot.dtsi      |  1 +
> > > > > >  board/sifive/fu540/Kconfig                    |  3 +++
> > > > > >  doc/board/sifive/fu540.rst                    | 19 +++++++++++++++++++
> > > > > >  3 files changed, 23 insertions(+)
> > > > > >
> > > > > > diff --git a/arch/riscv/dts/hifive-unleashed-a00-u-boot.dtsi
> > b/arch/riscv/dts/hifive-unleashed-a00-u-boot.dtsi
> > > > > > index 25ec8265a5..d7a64134db 100644
> > > > > > --- a/arch/riscv/dts/hifive-unleashed-a00-u-boot.dtsi
> > > > > > +++ b/arch/riscv/dts/hifive-unleashed-a00-u-boot.dtsi
> > > > > > @@ -5,6 +5,7 @@
> > > > > >
> > > > > >  / {
> > > > > >         aliases {
> > > > > > +               spi0 = &qspi0;
> > > > > >                 spi2 = &qspi2;
> > > > > >         };
> > > > > >  };
> > > > > > diff --git a/board/sifive/fu540/Kconfig b/board/sifive/fu540/Kconfig
> > > > > > index 5d65080429..c5a1bca03c 100644
> > > > > > --- a/board/sifive/fu540/Kconfig
> > > > > > +++ b/board/sifive/fu540/Kconfig
> > > > > > @@ -26,6 +26,7 @@ config BOARD_SPECIFIC_OPTIONS # dummy
> > > > > >         imply CMD_FS_GENERIC
> > > > > >         imply CMD_NET
> > > > > >         imply CMD_PING
> > > > > > +       imply CMD_SF
> > > > > >         imply CLK_SIFIVE
> > > > > >         imply CLK_SIFIVE_FU540_PRCI
> > > > > >         imply DOS_PARTITION
> > > > > > @@ -40,6 +41,8 @@ config BOARD_SPECIFIC_OPTIONS # dummy
> > > > > >         imply SIFIVE_SERIAL
> > > > > >         imply SPI
> > > > > >         imply SPI_SIFIVE
> > > > > > +       imply SPI_FLASH
> > > > > > +       imply SPI_FLASH_ISSI
> > > > > >         imply MMC
> > > > > >         imply MMC_SPI
> > > > > >         imply MMC_BROKEN_CD
> > > > > > diff --git a/doc/board/sifive/fu540.rst b/doc/board/sifive/fu540.rst
> > > > > > index 91b94ee06f..2e70cad02e 100644
> > > > > > --- a/doc/board/sifive/fu540.rst
> > > > > > +++ b/doc/board/sifive/fu540.rst
> > > > > > @@ -366,3 +366,22 @@ load uImage.
> > > > > >
> > > > > >     Please press Enter to activate this console.
> > > > > >     / #
> > > > > > +
> > > > > > +Sample spi nor flash test
> > > > > > +-------------------------
> > > > > > +
> > > > > > +.. code-block:: none
> > > > > > +
> > > > > > +   => sf probe 0:2
> > > > >
> > > > > The cs number can't be 2. It should be zero.
> > > >
> > > > With this patch series, we got crazy duplicated flash devices created,
> > > > see below:
> > > >
> > > > => sf probe
> > > > unrecognized JEDEC id bytes: ff, ff, ff
> > > > Failed to initialize SPI flash at 0:0 (error -2)
> > > > => sf probe 0:2
> > > > SF: Detected is25wp256 with page size 256 Bytes, erase size 4 KiB, total 32
> > MiB
> > > > => sf probe 0:4
> > > > SF: Detected is25wp256 with page size 256 Bytes, erase size 4 KiB, total 32
> > MiB
> > > > => sf probe 0:6
> > > > SF: Detected is25wp256 with page size 256 Bytes, erase size 4 KiB, total 32
> > MiB
> > > > => dm tree
> > > >  Class     Index  Probed  Driver                Name
> > > > -----------------------------------------------------------
> > > >  root          0  [ + ]   root_driver           root_driver
> > > >  simple_bus    0  [ + ]   generic_simple_bus    |-- soc
> > > >  clk           0  [ + ]   sifive-fu540-prci     |   |--
> > > > clock-controller at 10000000
> > > >  serial        0  [ + ]   serial_sifive         |   |-- serial at 10010000
> > > >  serial        1  [   ]   serial_sifive         |   |-- serial at 10011000
> > > >  spi           0  [ + ]   sifive_spi            |   |-- spi at 10040000
> > > >  spi_flash     0  [   ]   spi_flash_std         |   |   |-- flash at 0
> > > >  spi_flash     1  [ + ]   spi_flash_std         |   |   |-- spi_flash at 0:2
> > > >  spi_flash     2  [ + ]   spi_flash_std         |   |   |-- spi_flash at 0:4
> > > >  spi_flash     3  [ + ]   spi_flash_std         |   |   `-- spi_flash at 0:6
> > > >
> > > > With my patch series below
> > > > http://patchwork.ozlabs.org/project/uboot/list/?series=129736
> > > >
> > > > the CS number check was added to the SPI flash hence we got:
> > > >
> > > > => sf probe
> > > > unrecognized JEDEC id bytes: ff, ff, ff
> > > > Failed to initialize SPI flash at 0:0 (error -2)
> > > > => sf probe 2
> > > > Invalid cs 2 (err=-22)
> > > > Invalid cs 2 (err=-22)
> > > > Invalid chip select 0:2 (err=-22)
> > > > Failed to initialize SPI flash at 0:2 (error -22)
> > > > => sf probe 4
> > > > Invalid cs 4 (err=-22)
> > > > Invalid cs 4 (err=-22)
> > > > Invalid chip select 0:4 (err=-22)
> > > > Failed to initialize SPI flash at 0:4 (error -22)
> > > >
> > > > So we still need figure out why CS number 0 cannot work on SiFive.
> > >
> > > The existing quad wire that driver pushing for flash seems not
> > > detecting flash at CS 0 so making cr to single wire detecting flash at
> >
> > I vaguely remember someone from SiFive posted a patch that forced the
> > SPI controller to work under single wire mode. Maybe someone from
> > SiFive could help explain the weird behavior as you mentioned.
> >
> Sorry, I had not been closely looking into this thread.
> Yes, the initial patch posted was to add support for is25wp256 device.
> https://patchwork.ozlabs.org/patch/1146523/
> but it seems it was bricking the board, and later couldn't follow-up on this.
> IIUC, spi_nor_scan has default reg_proto set to 1_1_1, and further parses
> slave mode and accordingly sets the hwcaps fields. Now since the device tree
> set's the slave mode to 4 bit mode based on the tx-bus-width, this creates
> a conflict due to which reg_read fails and so the sf probe fails too.

The strange thing is that the 'sf probe' only fails at CS 0, but
succeeds at CS 2/4/6/8/...

Is this strange behavior caused by the default reg_proto set to 1_1_1
in spi_nor_scan()?

> Now forcing the SPI-controller in single wire mode helped the sf probe to
> detect the flash. Alternatively I think if we use bitlen passed by spi_mem_exec_op
> and prepare spi transfer's in controller based on max of t->rx_nbits, t->tx_nbits as
> done in linux driver this should work. Any thoughts on this?
>

Maybe Jagan can comment this.

Regards,
Bin


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