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Date:   Mon, 20 Jun 2022 13:07:45 +0300
From:   Ivan Bornyakov <i.bornyakov@metrotek.ru>
To:     Conor.Dooley@microchip.com
Cc:     mdf@kernel.org, hao.wu@intel.com, yilun.xu@intel.com,
        trix@redhat.com, corbet@lwn.net, robh+dt@kernel.org,
        krzysztof.kozlowski+dt@linaro.org, linux-fpga@vger.kernel.org,
        devicetree@vger.kernel.org, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, system@metrotek.ru
Subject: Re: [PATCH v20 0/4] Microchip Polarfire FPGA manager
Message-ID: <20220620100745.yxjmq2qtsicxlrgn@h-e2.ddg>
References: <20220617134846.19859-1-i.bornyakov@metrotek.ru>
 <2e24734d-038c-b937-aeab-8e348a04b827@microchip.com>
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On Sun, Jun 19, 2022 at 06:39:28PM +0000, Conor.Dooley@microchip.com wrote:
> On 17/06/2022 14:48, Ivan Bornyakov wrote:
> > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> > 
> > Add support to the FPGA manager for programming Microchip Polarfire
> > FPGAs over slave SPI interface with .dat formatted bitsream image.
> 
> btw Ivan,
> Do we want to create a maintainers entry for this?
> I am happy to either:
> - Create a new entry with whatever combination of ourselves as
>   maintainers/reviewers.
> - Or if you don't want to take that on, you can add the driver
>   to the existing PolarFire SoC MAINTAINERS entry probably with
>   a rename to "RISC-V/MICROCHIP FPGA SUPPORT" or similar.
> 
> Or if you have another suggestion, lmk!
> Thanks,
> Conor.
> 

Hi, Conor!

As there is no dedicated entries for any of FPGA manager drivers and
I have no access to any info that is not pablicly available, I would
suggest you to do the latter, i.e. to add the driver to the existing
PolarFire SoC MAINTAINERS entry, once this patch series accepted.

> > 
> > Changelog:
> >   v1 -> v2: fix printk formating
> >   v2 -> v3:
> >    * replace "microsemi" with "microchip"
> >    * replace prefix "microsemi_fpga_" with "mpf_"
> >    * more sensible .compatible and .name strings
> >    * remove unused defines STATUS_SPI_VIOLATION and STATUS_SPI_ERROR
> >   v3 -> v4: fix unused variable warning
> >     Put 'mpf_of_ids' definition under conditional compilation, so it
> >     would not hang unused if CONFIG_OF is not enabled.
> >   v4 -> v5:
> >    * prefix defines with MPF_
> >    * mdelay() -> usleep_range()
> >    * formatting fixes
> >    * add DT bindings doc
> >    * rework fpga_manager_ops.write() to fpga_manager_ops.write_sg()
> >      We can't parse image header in write_init() because image header
> >      size is not known beforehand. Thus parsing need to be done in
> >      fpga_manager_ops.write() callback, but fpga_manager_ops.write()
> >      also need to be reenterable. On the other hand,
> >      fpga_manager_ops.write_sg() is called once. Thus, rework usage of
> >      write() callback to write_sg().
> >   v5 -> v6: fix patch applying
> >      I forgot to clean up unrelated local changes which lead to error on
> >      patch 0001-fpga-microchip-spi-add-Microchip-MPF-FPGA-manager.patch
> >      applying on vanilla kernel.
> >   v6 -> v7: fix binding doc to pass dt_binding_check
> >   v7 -> v8: another fix for dt_binding_check warning
> >   v8 -> v9:
> >    * add another patch to support bitstream offset in FPGA image buffer
> >    * rework fpga_manager_ops.write_sg() back to fpga_manager_ops.write()
> >    * move image header parsing from write() to write_init()
> >   v9 -> v10:
> >    * add parse_header() callback to fpga_manager_ops
> >    * adjust fpga_mgr_write_init[_buf|_sg]() for parse_header() usage
> >    * implement parse_header() in microchip-spi driver
> >   v10 -> v11: include missing unaligned.h to microchip-spi
> >      fix error: implicit declaration of function 'get_unaligned_le[16|32]'
> >   v11 -> v12:
> >    * microchip-spi: double read hw status, ignore first read, because it
> >      can be unreliable.
> >    * microchip-spi: remove sleep between status readings in
> >      poll_status_not_busy() to save a few seconds. Status is polled on
> >      every 16 byte writes - that is quite often, therefore
> >      usleep_range() accumulate to a considerable number of seconds.
> >   v12 -> v13:
> >    * fpga-mgr: separate fpga_mgr_parse_header_buf() from
> >      fpga_mgr_write_init_buf()
> >    * fpga-mgr: introduce FPGA_MGR_STATE_PARSE_HEADER and
> >      FPGA_MGR_STATE_PARSE_HEADER_ERR fpga_mgr_states
> >    * fpga-mgr: rename fpga_mgr_write_init_sg() to fpga_mgr_prepare_sg()
> >      and rework with respect to a new fpga_mgr_parse_header_buf()
> >    * fpga-mgr: rework write accounting in fpga_mgr_buf_load_sg() for
> >      better clarity
> >    * microchip-spi: rename MPF_STATUS_POLL_TIMEOUT to
> >      MPF_STATUS_POLL_RETRIES
> >    * microchip-spi: add comment about status reading quirk to
> >      mpf_read_status()
> >    * microchip-spi: rename poll_status_not_busy() to mpf_poll_status()
> >      and add comment.
> >    * microchip-spi: make if statement in mpf_poll_status() easier to
> >      read.
> >   v13 -> v14:
> >    * fpga-mgr: improvements from Xu Yilun in
> >       - fpga_mgr_parse_header_buf()
> >       - fpga_mgr_write_init_buf()
> >       - fpga_mgr_prepare_sg()
> >       - fpga_mgr_buf_load_sg()
> >    * fpga-mgr: add check for -EAGAIN from fpga_mgr_parse_header_buf()
> >      when called from fpga_mgr_buf_load_mapped()
> >    * microchip-spi: remove excessive cs_change from second spi_transfer
> >      in mpf_read_status()
> >    * microchip-spi: change type of components_size_start,
> >      bitstream_start, i from size_t to u32 in mpf_ops_parse_header()
> >   v14 -> v15: eliminate memcpy() in mpf_ops_write()
> >     Eliminate excessive memcpy() in mpf_ops_write() by using
> >     spi_sync_transfer() instead of spi_write().
> >   v15 -> v16:
> >    * microchip-spi: change back components_size_start and
> >      bitstream_start variables types to size_t, i - to u16 in
> >      mpf_ops_parse_header()
> >    * fpga-mgr: rename fpga_parse_header_buf() to
> >      fpga_parse_header_mapped(). It serves only mapped FPGA image now,
> >      adjust it accordingly.
> >    * fpga-mgr: separate fpga_mgr_parse_header_sg_first() and
> >      fpga_mgr_parse_header_sg() from fpga_mgr_prepare_sg()
> >   v16 -> v17:
> >    * fpga-mgr: return size of allocated header from
> >      fpga_mgr_parse_header_sg(), add `char **ret_buf` to function args
> >      to save pointer to allocated header. This allow us to call
> >      fpga_mgr_write_init_buf() with exact size of allocated header.
> >    * document parse_header() callback in fpga-mgr.rst
> >   v17 -> v18:
> >    * fpga-mgr: change back fpga_mgr_parse_header_sg() to return
> >      allocated buffer but set buffer size into output parameter
> >    * fpga-mgr: check returned pointer from krealloc for ZERO_OR_NULL_PTR
> >      in fpga_mgr_paese_header_sg() as krealloc may return ZERO_SIZE_PTR.
> >    * fpga-mgr: in fpga_mgr_prepare_sg() return fpga_mgr_write_init() on
> >      fast path only when both initial_header_size and parse_header() are
> >      not defined.
> >    * docs: fpga-mgr: a few rewords from Xu Yilun
> >   v18 -> v19:
> >    * microchip-spi: split multiple assignments on a single line in
> >      functions mpf_read_status() and mpf_ops_parse_header()
> >    * fpga-mgr: add braces {} around "else if" arm in
> >      fpga_mgr_prepare_sg()
> >    * fpga-mgr: don't reuse krealloc() arg in fpga_mgr_parse_header_sg().
> >      If krealloc() returns NULL, it doesn't free the original.
> >   v19 -> v20:
> >    * fpga-mgr: initialize info->header_size with
> >      mops->initial_header_size at fpga_mgr_load().
> >    * fpga-mgr: add mops->skip_header boolean flag. Adjust skipping
> >      header before write to check against skip_header flag instead of
> >      mere presence of info->header_size.
> >    * fpga-mgr: split check for ZERO_OR_NULL_PTR() after realloc() in
> >      fpga_mgr_parse_header_sg() function to check against zero header +
> >      check against NULL returned from realloc().
> >    * docs: fpga-mgr: adjust for skip_header flag.
> >    * microchip-spi: add skip_header to mpf_ops.
> > 
> > Ivan Bornyakov (4):
> >   fpga: fpga-mgr: support bitstream offset in image buffer
> >   docs: fpga: mgr: document parse_header() callback
> >   fpga: microchip-spi: add Microchip MPF FPGA manager
> >   dt-bindings: fpga: add binding doc for microchip-spi fpga mgr
> > 
> >  .../fpga/microchip,mpf-spi-fpga-mgr.yaml      |  44 ++
> >  Documentation/driver-api/fpga/fpga-mgr.rst    |  27 +-
> >  drivers/fpga/Kconfig                          |   8 +
> >  drivers/fpga/Makefile                         |   1 +
> >  drivers/fpga/fpga-mgr.c                       | 236 +++++++++--
> >  drivers/fpga/microchip-spi.c                  | 398 ++++++++++++++++++
> >  include/linux/fpga/fpga-mgr.h                 |  22 +-
> >  7 files changed, 703 insertions(+), 33 deletions(-)
> >  create mode 100644 Documentation/devicetree/bindings/fpga/microchip,mpf-spi-fpga-mgr.yaml
> >  create mode 100644 drivers/fpga/microchip-spi.c
> > 
> > --
> > 2.25.1
> > 
> > 
>