From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Mark Brown <broonie@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@vger.kernel.org>,
Vignesh Raghavendra <vigneshr@ti.com>,
Tudor Ambarus <tudor.ambarus@microchip.com>,
Richard Weinberger <richard@nod.at>, Sekhar Nori <nsekhar@ti.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Rob Herring <robh+dt@kernel.org>,
linux-spi <linux-spi@vger.kernel.org>,
Boris Brezillon <boris.brezillon@collabora.com>,
MTD Maling List <linux-mtd@lists.infradead.org>,
Miquel Raynal <miquel.raynal@bootlin.com>,
Pratyush Yadav <p.yadav@ti.com>
Subject: Re: [PATCH v2 01/11] dt-bindings: spi: allow expressing DTR capability
Date: Thu, 27 Feb 2020 17:40:31 +0100 [thread overview]
Message-ID: <CAMuHMdWMCDzQm0tjpybJZyHy4imbC9NqRXP5d4C0xgxQx-Pf8g@mail.gmail.com> (raw)
In-Reply-To: <20200227162842.GE4062@sirena.org.uk>
Hi Mark,
On Thu, Feb 27, 2020 at 5:28 PM Mark Brown <broonie@kernel.org> wrote:
> On Thu, Feb 27, 2020 at 05:11:47PM +0100, Boris Brezillon wrote:
> > Pratyush Yadav <p.yadav@ti.com> wrote:
>
> > > Allow spi devices to express DTR receive and transmit capabilities via
> > > the properties "spi-rx-dtr" and "spi-tx-dtr".
>
> > Is the RX/TX granularity really useful?
>
> It's what we do for other properties, and if this is anything like the
> other things adding extra wiring you can't assume that the ability to
> use the feature for TX implies RX.
Double Transfer Rate uses the same wire.
But as you sample at both the rising and the falling edges of the clock, this
makes the cpha setting meaningless for such transfers, I think ;-)
However, as the future may bring us QDR, perhaps this should not be a
boolean flag, but an integer value?
Cfr. spi-tx-bus-width vs. the original spi-tx-dual/spi-tx-quad proposal.
What would be a good name (as we only need one)? spi-data-phases?
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/
next prev parent reply other threads:[~2020-02-27 16:40 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-26 9:36 [PATCH v2 00/11] mtd: spi-nor: add xSPI Octal DTR support Pratyush Yadav
2020-02-26 9:36 ` [PATCH v2 01/11] dt-bindings: spi: allow expressing DTR capability Pratyush Yadav
2020-02-27 16:11 ` Boris Brezillon
2020-02-27 16:28 ` Mark Brown
2020-02-27 16:40 ` Geert Uytterhoeven [this message]
2020-02-27 16:44 ` Mark Brown
2020-02-27 17:03 ` Geert Uytterhoeven
2020-03-02 9:53 ` Pratyush Yadav
2020-02-27 17:06 ` Boris Brezillon
2020-02-27 16:29 ` Geert Uytterhoeven
2020-02-28 9:46 ` Pratyush Yadav
2020-02-26 9:36 ` [PATCH v2 02/11] spi: set mode bits for "spi-rx-dtr" and "spi-tx-dtr" Pratyush Yadav
2020-02-27 16:23 ` Boris Brezillon
2020-03-02 9:48 ` Pratyush Yadav
2020-03-02 10:20 ` Boris Brezillon
2020-02-26 9:36 ` [PATCH v2 03/11] spi: spi-mem: allow specifying whether an op is DTR or not Pratyush Yadav
2020-02-27 16:36 ` Boris Brezillon
2020-02-26 9:36 ` [PATCH v2 04/11] spi: spi-mem: allow specifying a command's extension Pratyush Yadav
2020-02-27 16:44 ` Boris Brezillon
2020-02-28 9:41 ` Pratyush Yadav
2020-02-26 9:36 ` [PATCH v2 05/11] spi: cadence-quadspi: Add support for octal DTR flashes Pratyush Yadav
2020-02-26 9:36 ` [PATCH v2 06/11] mtd: spi-nor: add support for DTR protocol Pratyush Yadav
2020-02-27 16:58 ` Boris Brezillon
2020-02-28 9:36 ` Pratyush Yadav
2020-02-28 10:53 ` Boris Brezillon
2020-02-28 12:07 ` Pratyush Yadav
2020-02-28 13:18 ` Boris Brezillon
2020-02-26 9:36 ` [PATCH v2 07/11] mtd: spi-nor: get command opcode extension type from BFPT Pratyush Yadav
2020-02-26 9:37 ` [PATCH v2 08/11] mtd: spi-nor: parse xSPI Profile 1.0 table Pratyush Yadav
2020-02-26 9:37 ` [PATCH v2 09/11] mtd: spi-nor: use dummy cycle and address width info from SFDP Pratyush Yadav
2020-02-26 9:37 ` [PATCH v2 10/11] mtd: spi-nor: enable octal DTR mode when possible Pratyush Yadav
2020-02-26 9:37 ` [PATCH v2 11/11] mtd: spi-nor: add support for Cypress Semper flash Pratyush Yadav
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAMuHMdWMCDzQm0tjpybJZyHy4imbC9NqRXP5d4C0xgxQx-Pf8g@mail.gmail.com \
--to=geert@linux-m68k.org \
--cc=boris.brezillon@collabora.com \
--cc=broonie@kernel.org \
--cc=devicetree@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mtd@lists.infradead.org \
--cc=linux-spi@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=miquel.raynal@bootlin.com \
--cc=nsekhar@ti.com \
--cc=p.yadav@ti.com \
--cc=richard@nod.at \
--cc=robh+dt@kernel.org \
--cc=tudor.ambarus@microchip.com \
--cc=vigneshr@ti.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).