From: Mark Brown <broonie@kernel.org>
To: apronin@chromium.org
Cc: linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org
Subject: Re: [PATCH 3/4] spi: Add option to insert delay between transactions
Date: Fri, 1 Jul 2016 09:16:36 +0100 [thread overview]
Message-ID: <20160701081636.GC6247@sirena.org.uk> (raw)
In-Reply-To: <1467258867-117727-3-git-send-email-apronin@chromium.org>
[-- Attachment #1: Type: text/plain, Size: 812 bytes --]
On Wed, Jun 29, 2016 at 08:54:26PM -0700, apronin@chromium.org wrote:
> Some devices may need CS to be deasserted for some time
> between transactions. Added a new capability to guarantee
> a delay between SPI transactions for the device.
This seems like even more of a per device thing - it's a very rare
requirement (I'm guessing for some SPI controller coprocessor) and
there's such a wide range of potential patterns that might be needed
by different devices.
> + if (msg->spi->xfer_delay)
> + mdelay(msg->spi->xfer_delay);
> +
> spi_set_cs(msg->spi, true);
This isn't a delay between messages, it's a delay before asserting
chip select which will happen every single time we do anything
regardless of if there was any activity immediately before or not.
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 473 bytes --]
next prev parent reply other threads:[~2016-07-01 9:00 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-30 3:54 [PATCH 1/4] spi: Add option to wake a device by toggling CS apronin
2016-06-30 3:54 ` [PATCH 2/4] spi: Document " apronin
2016-06-30 7:12 ` Geert Uytterhoeven
2016-07-01 4:32 ` Doug Anderson
2016-06-30 3:54 ` [PATCH 3/4] spi: Add option to insert delay between transactions apronin
2016-07-01 4:44 ` Doug Anderson
2016-07-01 8:16 ` Mark Brown [this message]
2016-06-30 3:54 ` [PATCH 4/4] spi: Document " apronin
2016-06-30 7:12 ` Geert Uytterhoeven
2016-07-01 4:45 ` Doug Anderson
2016-07-01 4:23 ` [PATCH 1/4] spi: Add option to wake a device by toggling CS Doug Anderson
2016-07-01 8:21 ` Mark Brown
2016-07-01 17:05 ` Doug Anderson
2016-07-01 17:17 ` Mark Brown
2016-07-02 2:02 ` Andrey Pronin
2016-07-01 8:02 ` Mark Brown
2016-07-02 1:45 ` Andrey Pronin
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=20160701081636.GC6247@sirena.org.uk \
--to=broonie@kernel.org \
--cc=apronin@chromium.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-spi@vger.kernel.org \
/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