Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1201644

Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read

From Mark Brown <broonie@kernel.org>
Newsgroups linux.kernel
Subject Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read
Date 2015-08-06 13:10 +0200
Message-ID <pUrdE-77S-9@gated-at.bofh.it> (permalink)
References (5 earlier) <pU6iR-1zm-9@gated-at.bofh.it> <pU6sy-1KO-13@gated-at.bofh.it> <pUplw-4re-17@gated-at.bofh.it> <pUqhA-5Mv-11@gated-at.bofh.it> <pUqAW-69b-5@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


[Multipart message — attachments visible in raw view] - view raw

On Thu, Aug 06, 2015 at 11:22:25AM +0100, Russell King - ARM Linux wrote:

> If that's the case, then maybe you should consider whether using the SPI
> bus infrastructure is really the best way forward.  Would it make more
> sense instead to adopt a different software structure, something more
> high-level like:

>      +-------------------------------------------+
>      |          m25p80 high-level driver         |
>      +----------------------+--------------------+
>      |   SPI m25p80 driver  |                    |
>      +----------------------+                    |
>      |      SPI layer       |  Special driver    |
>      +----------------------+                    |
>      |    SPI bus driver    |                    |
>      +----------------------+--------------------+
>      |     SPI hardware     |  Special hardware  |
>      +----------------------+--------------------+

Yes, that's what's been talked about before - for some of these devices
they're sufficiently flash specialist that we just don't bother exposing
a SPI interface at all though AIUI they could be persuaded to do it.  It
isn't entirely clear that we want exactly that split, if the devices are
reasonable SPI controllers we will want to handle the case where they
have flash and non-flash devices on the same bus.  For that there is
going to be some generalisable work possible for managing switching
between memory mapped and SPI modes where those are mutually exclusive,
especially if the switch between them isn't free.

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Mark Brown <broonie@kernel.org> - 2015-08-04 18:00 +0200
  Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read "R, Vignesh" <vigneshr@ti.com> - 2015-08-04 20:10 +0200
    Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Michal Suchanek <hramrach@gmail.com> - 2015-08-05 07:30 +0200
      Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Vignesh R <vigneshr@ti.com> - 2015-08-05 07:40 +0200
        Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Michal Suchanek <hramrach@gmail.com> - 2015-08-05 08:00 +0200
    Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Mark Brown <broonie@kernel.org> - 2015-08-05 14:00 +0200
      Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Michal Suchanek <hramrach@gmail.com> - 2015-08-05 14:50 +0200
        Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Mark Brown <broonie@kernel.org> - 2015-08-05 14:50 +0200
          Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Michal Suchanek <hramrach@gmail.com> - 2015-08-05 15:00 +0200
            Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Mark Brown <broonie@kernel.org> - 2015-08-06 11:10 +0200
              Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Michal Suchanek <hramrach@gmail.com> - 2015-08-06 12:10 +0200
                Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Russell King - ARM Linux <linux@arm.linux.org.uk> - 2015-08-06 12:30 +0200
                Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Mark Brown <broonie@kernel.org> - 2015-08-06 13:10 +0200
                Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Michal Suchanek <hramrach@gmail.com> - 2015-08-06 13:10 +0200
                Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Vignesh R <vigneshr@ti.com> - 2015-08-06 14:30 +0200
                Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Russell King - ARM Linux <linux@arm.linux.org.uk> - 2015-08-06 16:00 +0200
                Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Geert Uytterhoeven <geert@linux-m68k.org> - 2015-08-06 18:20 +0200
                Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Michal Suchanek <hramrach@gmail.com> - 2015-08-06 20:30 +0200
                Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Russell King - ARM Linux <linux@arm.linux.org.uk> - 2015-08-06 23:40 +0200
                Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Michal Suchanek <hramrach@gmail.com> - 2015-08-07 09:40 +0200
                Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Vignesh R <vigneshr@ti.com> - 2015-08-07 10:40 +0200
                Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Martin Sperl <martin@sperl.org> - 2015-08-07 10:30 +0200
                Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Michal Suchanek <hramrach@gmail.com> - 2015-08-07 12:20 +0200
                Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Vignesh R <vigneshr@ti.com> - 2015-08-12 11:30 +0200
                Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Mark Brown <broonie@kernel.org> - 2015-08-06 18:50 +0200
                Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Mark Brown <broonie@kernel.org> - 2015-08-06 20:30 +0200
                Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Mark Brown <broonie@kernel.org> - 2015-08-06 13:30 +0200
                Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Michal Suchanek <hramrach@gmail.com> - 2015-08-06 13:50 +0200
                Re: [RFC PATCH 1/5] spi: introduce flag for memory mapped read Mark Brown <broonie@kernel.org> - 2015-08-06 18:10 +0200

csiph-web