From: Sebastian Andrzej Siewior <bigeasy-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>
To: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
Cc: Mingkai Hu <Mingkai.hu-KZfg59tc24xl57MIdRCFDg@public.gmane.org>,
Sebastian Andrzej Siewior
<bigeasy-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>
Subject: [PATCH 1/2] spi/fsl-espi: make the clock computation easier to read
Date: Thu, 15 Mar 2012 18:42:31 +0100 [thread overview]
Message-ID: <1331833352-15058-1-git-send-email-bigeasy@linutronix.de> (raw)
The -1 +1 thingy should probably do what DIV_ROUND_UP does. The 4 is 2
the "platform_clock => sysclock" and 2 from the computation part. The 64
is the same 4 times 16.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>
---
drivers/spi/spi-fsl-espi.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/spi/spi-fsl-espi.c b/drivers/spi/spi-fsl-espi.c
index d770f03..43350f9 100644
--- a/drivers/spi/spi-fsl-espi.c
+++ b/drivers/spi/spi-fsl-espi.c
@@ -180,7 +180,7 @@ static int fsl_espi_setup_transfer(struct spi_device *spi,
if ((mpc8xxx_spi->spibrg / hz) > 64) {
cs->hw_mode |= CSMODE_DIV16;
- pm = (mpc8xxx_spi->spibrg - 1) / (hz * 64) + 1;
+ pm = DIV_ROUND_UP(mpc8xxx_spi->spibrg, hz * 16 * 4);
WARN_ONCE(pm > 16, "%s: Requested speed is too low: %d Hz. "
"Will use %d Hz instead.\n", dev_name(&spi->dev),
@@ -188,7 +188,7 @@ static int fsl_espi_setup_transfer(struct spi_device *spi,
if (pm > 16)
pm = 16;
} else {
- pm = (mpc8xxx_spi->spibrg - 1) / (hz * 4) + 1;
+ pm = DIV_ROUND_UP(mpc8xxx_spi->spibrg, hz * 4);
}
if (pm)
pm--;
--
1.7.9.1
------------------------------------------------------------------------------
This SF email is sponsosred by:
Try Windows Azure free for 90 days Click Here
http://p.sf.net/sfu/sfd2d-msazure
next reply other threads:[~2012-03-15 17:42 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-15 17:42 Sebastian Andrzej Siewior [this message]
[not found] ` <1331833352-15058-1-git-send-email-bigeasy-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>
2012-03-15 17:42 ` [PATCH 2/2] spi/fsl-espi: Make sure pm is within 2..32 Sebastian Andrzej Siewior
[not found] ` <1331833352-15058-2-git-send-email-bigeasy-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>
2012-03-15 21:15 ` Grant Likely
2012-03-15 21:15 ` [PATCH 1/2] spi/fsl-espi: make the clock computation easier to read Grant Likely
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=1331833352-15058-1-git-send-email-bigeasy@linutronix.de \
--to=bigeasy-hfztesqfncyowbw4kg4ksq@public.gmane.org \
--cc=Mingkai.hu-KZfg59tc24xl57MIdRCFDg@public.gmane.org \
--cc=spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.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;
as well as URLs for NNTP newsgroup(s).