From: Mark Brown <broonie@kernel.org>
To: Baolin Wang <baolin.wang@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Orson Zhai <orsonzhai@gmail.com>,
Chunyan Zhang <zhang.lyra@gmail.com>,
lanqing.liu@spreadtrum.com, linux-spi@vger.kernel.org,
DTML <devicetree@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/2] dt-bindings: spi: Add Spreadtrum SPI controller documentation
Date: Wed, 8 Aug 2018 10:50:25 +0100 [thread overview]
Message-ID: <20180808095025.GB9346@sirena.org.uk> (raw)
In-Reply-To: <CAMz4kuJsyKv_fvrqRR3pdfKsLVy53Uj0KX+m_9jLxpcVcMvs9g@mail.gmail.com>
[-- Attachment #1: Type: text/plain, Size: 1221 bytes --]
On Wed, Aug 08, 2018 at 10:26:42AM +0800, Baolin Wang wrote:
> Sorry for confusing. Let me try to explain it explicitly.
> We can set the word size (bits_per_word) for each transmission, for
> our SPI controller, after every word size transmission, we need one
> interval time (hardware automatically) to make sure the slave has
> enough time to receive the whole data.
OK, so it's an inter word delay. Some other controllers definitely have
the same feature.
> Yes, I agree we should configure it at runtime by the device, but we
> did not find one member to use in 'struct spi_transfer', we just find
> one similar 'delay_usecs' member in 'struct spi_transfer' but not
> same. We can use 'delay_usecs' to set our hardware interval value,
> but we should clean it when transfer is done, since we do not need to
> delay after the transfer in spi_transfer_one _message(). Or can we add
> one new member maybe named 'word_interval' to indicate the interval
> time between word size transmission?
Right, I don't think we added this yet (if we did I can't see it). I'd
add a new field to spi_transfer for this, then other controllers with
the same support can implement it as well and drivers can start using
it too.
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]
next prev parent reply other threads:[~2018-08-08 9:50 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-07 10:43 [PATCH 1/2] dt-bindings: spi: Add Spreadtrum SPI controller documentation Baolin Wang
2018-08-07 10:43 ` [PATCH 2/2] spi: sprd: Add SPI driver for Spreadtrum SC9860 Baolin Wang
2018-08-07 14:24 ` Mark Brown
2018-08-08 2:45 ` Baolin Wang
2018-08-08 9:31 ` Mark Brown
2018-08-08 9:33 ` Baolin Wang
2018-08-07 17:10 ` Trent Piepho
2018-08-08 3:19 ` Baolin Wang
2018-08-08 19:08 ` Trent Piepho
2018-08-09 3:23 ` Baolin Wang
2018-08-07 13:41 ` [PATCH 1/2] dt-bindings: spi: Add Spreadtrum SPI controller documentation Mark Brown
2018-08-08 2:26 ` Baolin Wang
2018-08-08 9:50 ` Mark Brown [this message]
2018-08-08 10:35 ` Baolin Wang
2018-08-08 10:54 ` Mark Brown
2018-08-08 11:07 ` Baolin Wang
2018-08-08 18:57 ` Trent Piepho
2018-08-09 3:03 ` Baolin Wang
2018-08-14 20:27 ` Rob Herring
2018-08-15 2:17 ` Baolin Wang
2018-08-14 20:21 ` Rob Herring
2018-08-15 1:44 ` Baolin Wang
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=20180808095025.GB9346@sirena.org.uk \
--to=broonie@kernel.org \
--cc=baolin.wang@linaro.org \
--cc=devicetree@vger.kernel.org \
--cc=lanqing.liu@spreadtrum.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-spi@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=orsonzhai@gmail.com \
--cc=robh+dt@kernel.org \
--cc=zhang.lyra@gmail.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).