From: Vignesh Raghavendra <vigneshr@ti.com>
To: Tomer Maimon <tmaimon77@gmail.com>,
Boris Brezillon <boris.brezillon@collabora.com>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>,
bbrezillon@kernel.org, richard@nod.at,
tudor.ambarus@microchip.com,
Schrempf Frieder <frieder.schrempf@kontron.de>,
linux-spi@vger.kernel.org, broonie@kernel.org,
linux-mtd@lists.infradead.org, miquel.raynal@bootlin.com
Subject: Re: [RFC v1 0/3] *spi-mem: adding setup and callback function
Date: Thu, 1 Aug 2019 12:12:47 +0530 [thread overview]
Message-ID: <ac96da83-3b52-c030-cefa-e0d366fc3151@ti.com> (raw)
In-Reply-To: <CAP6Zq1hfVoS8+VU0rAtKAX7D22qTVHDMosiCRMKV8sQB_m0qOQ@mail.gmail.com>
Hi,
On 31/07/19 1:49 PM, Tomer Maimon wrote:
> Hi Vignesh,
>
> Does your new merge version will support direct spi-mem API?
>
No, I don't have a driver to test out dirmap APIs. So, that would need
to be added separately on top.
I have posted next version of my series here (expect more revisions):
https://patchwork.ozlabs.org/cover/1140269/
Feel free to test and rebase dirmap API addition on top of it.
Regards
Vignesh
> Thanks,
>
> Tomer
>
> On Tue, 30 Jul 2019 at 21:04, Boris Brezillon
> <boris.brezillon@collabora.com <mailto:boris.brezillon@collabora.com>>
> wrote:
>
> On Tue, 30 Jul 2019 23:18:25 +0530
> Vignesh Raghavendra <vigneshr@ti.com <mailto:vigneshr@ti.com>> wrote:
>
> > On 30-Jul-19 12:24 PM, Boris Brezillon wrote:
> > > Trimmed the recipient list a bit and used Frieder's new address.
> > > +Sergey
> > >
> > > On Mon, 29 Jul 2019 23:55:05 +0300
> > > Tomer Maimon <tmaimon77@gmail.com <mailto:tmaimon77@gmail.com>>
> wrote:
> > >
> > >> Hi Boris,
> > >>
> > >> Thanks for the prompt reply,
> > >>
> > >>
> > >>
> > >> On Mon, 29 Jul 2019 at 18:29, Boris Brezillon
> <boris.brezillon@collabora.com <mailto:boris.brezillon@collabora.com>>
> > >> wrote:
> > >>
> > >>> Hi Tomer,
> > >>>
> > >>> On Mon, 29 Jul 2019 17:25:01 +0300
> > >>> Tomer Maimon <tmaimon77@gmail.com
> <mailto:tmaimon77@gmail.com>> wrote:
> > >>>
> > >>>> Lately we have working on Flash interface unit (FIU) SPI
> driver that
> > >>>> using spi-mem interface, Our FIU HW module support direct
> Flash Rd//Wr.
> > >>>>
> > >>>> In our SOC (32 bit dual core ARM) we have 3 FIU's that using
> memory
> > >>> mapping as follow:
> > >>>>
> > >>>> FIU0 - have 2 chip select and each one have 128MB memory
> mapping (total
> > >>> 256MB memory mapping)
> > >>>> FIU1 - have 4 chip select and each one have 128MB memory
> mapping (total
> > >>> 512MB memory mapping)
> > >>>> FIU2 - have 4 chip select and each one have 16MB memory
> mapping (total
> > >>> 32MB memory mapping)
> > >>>>
> > >>>> Totally 800MB memory mapping.
> > >>>>
> > >>>> When the FIU driver probe it don't know the size of each
> Flash that
> > >>>> connected to the FIU, so the entire memory mapping is
> allocated for each
> > >>> FIU
> > >>>> according the FIU device tree memory map parameters.
> > >>>
> > >>> Do you need those mappings to be active to support simple reg
> accesses?
> > >>>
> > >>>> It means, if we enable all three FIU's the drivers will try
> to allocate
> > >>> totally 800MB.
> > >>>>
> > >>>> In 32bit system it is problematic because the kernel have
> only 1GB
> > >>>> of memory allocation so the vmalloc cannot take 800MB.
> > >>>>
> > >>>> When implementing the FIU driver in the mtd/spi-nor we
> allocating memory
> > >>> address only
> > >>>> for detected Flash with exact size (usually we are not using
> 128MB
> > >>> Flash), and in that case usually we allocating much less
> memory.
> > >>>>
> > >>>> To solve this issue we needed to overcome two things:
> > >>>>
> > >>>> 1. Get argument from the upper layer (spi-mem layer)
> > >>>> 2. Calling the get argument function after SPI_NOR_SCAN
> function.
> > >>> (the MTD Flash size filled in SPI_NOR_SCAN function)
> > >>>
> > >>> That's clearly breaking the layering we've tried to restore
> with the
> > >>> spi-nor/spi-mem split, and I don't see why this is needed
> since we now
> > >>> have a way to create direct mappings dynamically (with the
> dirmap API).
> > >>> Have you tried implementing the dirmap hooks in your driver?
> > >>
> > >>
> > >> Sorry but I wasn't familiar with the direct mapping in the
> spi-mem, it
> > >> seems it needed to implemented in the m25p80 driver as well, am
> I correct?
> > >
> > > There's this patch [1] floating around. IIRC, Sergey was waiting for
> > > the m25p80 -> spi-nor merge to send a v5. Vignesh, any updates
> on that
> > > one? If you don't have time to work on that, maybe Sergey could
> send a
> > > v5.
> > >
> >
> > I did send an updated series of merging m25p80 to spi-nor last
> week and
> > have received few comments. Will respin one more version this week
> > (mostly by tomorrow).
>
> Okay, great!
>
--
Regards
Vignesh
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prev parent reply other threads:[~2019-08-01 6:42 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-29 14:25 [RFC v1 0/3] *spi-mem: adding setup and callback function Tomer Maimon
2019-07-29 14:25 ` [RFC v1 1/3] spi: spi-mem: add spi-mem setup function Tomer Maimon
2019-07-29 14:25 ` [RFC v1 2/3] spi: spi-mem: add callback function to spi-mem device Tomer Maimon
2019-07-29 14:25 ` [RFC v1 3/3] mtd: m25p80: add get Flash size callback support Tomer Maimon
2019-07-29 15:28 ` [RFC v1 0/3] *spi-mem: adding setup and callback function Boris Brezillon
[not found] ` <CAP6Zq1iPXDX_Gtz6ZWYm3JoHgHjdapotVLGw-Lq4tc2X-6eAug@mail.gmail.com>
2019-07-30 6:54 ` Boris Brezillon
2019-07-30 16:53 ` Sergei Shtylyov
2019-07-30 17:48 ` Vignesh Raghavendra
2019-07-30 18:04 ` Boris Brezillon
[not found] ` <CAP6Zq1hfVoS8+VU0rAtKAX7D22qTVHDMosiCRMKV8sQB_m0qOQ@mail.gmail.com>
2019-08-01 6:42 ` Vignesh Raghavendra [this message]
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