[U-Boot] [PATCH v2 5/5] sifive: fu540: Enable spi-nor flash support
Jagan Teki
jagan at amarulasolutions.com
Fri Apr 17 09:59:35 CEST 2020
Hi Sagar,
On Tue, Apr 7, 2020 at 9:48 PM Sagar Kadam <sagar.kadam at sifive.com> wrote:
>
> Hello Jagan,
>
> > -----Original Message-----
> > From: Jagan Teki <jagan at amarulasolutions.com>
> > Sent: Monday, April 6, 2020 9:30 PM
> > To: Sagar Kadam <sagar.kadam at sifive.com>
> > Cc: Bin Meng <bmeng.cn at gmail.com>; Palmer Dabbelt
> > <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
> >
> > [External Email] Do not click links or attachments unless you recognize the
> > sender and know the content is safe
> >
> > Hi Sagar,
> >
> > On Sun, Apr 5, 2020 at 12:29 AM Sagar Kadam <sagar.kadam at sifive.com>
> > wrote:
> > >
> > > Hello Jagan,
> > >
> > > > -----Original Message-----
> > > > From: Jagan Teki <jagan at amarulasolutions.com>
> > > > Sent: Saturday, April 4, 2020 11:45 PM
> > > > To: Sagar Kadam <sagar.kadam at sifive.com>
> > > > Cc: Bin Meng <bmeng.cn at gmail.com>; Palmer Dabbelt
> > > > <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
> > > >
> > > > [External Email] Do not click links or attachments unless you recognize
> > the
> > > > sender and know the content is safe
> > > >
> > > > Hi Sagar,
> > > >
> > > > On Mon, Nov 18, 2019 at 2:29 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.
> > > > > 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?
> > > >
> > > > Thanks for the explanation. Infact I found how to handle this via
> > > > set_mode where I can preserve the mode into driver private structure
> > > > so-that the same can be used while setting cr. One of your patch doing
> > > > the same [1] but with every transfer bitlen(which seems reasonable).
> > > >
> > > Good to know that it is working in case of cs0 as well.
> > >
> > > > With this I can detect the flash at cs 0 but still flash still
> > > > requires bfpt fixes to make it work. I would like to poke your series
> > > > and do the changes accordingly (by keeping your respective
> > > > authorship), will that be fine?
> > > >
> > > Yes, please feel free to do so and also let me know if there is
> > > something which I can be of help here.
> >
> > Here are my observations.
> >
> Thanks for sharing your input/observations
>
> > 1. flash probe:
> > Probe happened to cs0 only when we enabled cs format propto value to
> > single (SIFIVE_SPI_FMT_PROTO_SINGLE). I did check it on the Linux
> > probe as well, same behaviour.
> >
>
> Yes, this matches with our understanding above, since reg read's during spi_nor_scan
> is 1-bit mode, and if cs proto value is set to SIFIVE_SPI_FMT_PROTO_SINGLE It works.
>
> > 2. flash operations:
> > Driver always assign single to format proto (say if we enable cr
> > format proto value based on bitlen) and it can't assign it ot dual and
> > quad even though the tx/rx-bus-width is 4 or 1
> >
> > flash operations are not working with quad, I did check the quad
> > enable bit, it is already enabled (RDSR is 0x40 BIT[6] is 1 that means
> > quad enabled by default). Is Linux flash operations working with quad
> > or does it revert back to default commands like fast read and page
> > program? could you please check?
> >
> > "flash operations are working only for fast read, that means 2-wire."
> >
>
> I checked in linux-5.6.0-rc7 flash operations for issi devices:
> - quad enable bit is set via issi_set_default_init.
> - post spi_nor_init, the read protocol is set to FAST_READ_QUAD I/O mode, I do see
> corresponding opcode during Read operations (opcode observed here is 0xec)
> - The page program is set and uses the SPI mode (opcode 12h).
I did manage to get the tx or rx bits logic related to u-boot via
buswidth. I can see it is working with quad read and quad write is not
working. Seems like Quad write is also not working even for Linux any
idea, why [2]?
[2] https://paste.ubuntu.com/p/nhZzQkkG33/
Jagan.
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