From: Linus Walleij <linus.walleij@linaro.org>
To: arm@kernel.org
Cc: Linus Walleij <linus.walleij@linaro.org>,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: dts: nomadik: Fix polarity of SPI CS
Date: Mon, 18 Mar 2019 16:31:22 +0100 [thread overview]
Message-ID: <20190318153122.10257-1-linus.walleij@linaro.org> (raw)
The SPI DT bindings are for historical reasons a pitfall,
the ability to flag a GPIO line as active high/low with
the second cell flags was introduced later so the SPI
subsystem will only accept the bool flag spi-cs-high
to indicate that the line is active high.
It worked by mistake, but the mistake was corrected
in another commit.
The comment in the DTS file was also misleading: this
CS is indeed active high.
Fixes: cffbb02dafa3 ("ARM: dts: nomadik: Augment NHK15 panel setting")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ARM SoC people: please apply this directly for fixes
if you're OK with it.
---
arch/arm/boot/dts/ste-nomadik-nhk15.dts | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/arch/arm/boot/dts/ste-nomadik-nhk15.dts b/arch/arm/boot/dts/ste-nomadik-nhk15.dts
index 04066f9cb8a3..f2f6558a00f1 100644
--- a/arch/arm/boot/dts/ste-nomadik-nhk15.dts
+++ b/arch/arm/boot/dts/ste-nomadik-nhk15.dts
@@ -213,12 +213,13 @@
gpio-sck = <&gpio0 5 GPIO_ACTIVE_HIGH>;
gpio-mosi = <&gpio0 4 GPIO_ACTIVE_HIGH>;
/*
- * It's not actually active high, but the frameworks assume
- * the polarity of the passed-in GPIO is "normal" (active
- * high) then actively drives the line low to select the
- * chip.
+ * This chipselect is active high. Just setting the flags
+ * to GPIO_ACTIVE_HIGH is not enough for the SPI DT bindings,
+ * it will be ignored, only the special "spi-cs-high" flag
+ * really counts.
*/
cs-gpios = <&gpio0 6 GPIO_ACTIVE_HIGH>;
+ spi-cs-high;
num-chipselects = <1>;
/*
--
2.20.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2019-03-18 15:31 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-18 15:31 Linus Walleij [this message]
2019-03-25 16:03 ` [PATCH] ARM: dts: nomadik: Fix polarity of SPI CS Arnd Bergmann
2019-04-07 10:16 ` Linus Walleij
2019-04-07 22:19 ` Olof Johansson
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=20190318153122.10257-1-linus.walleij@linaro.org \
--to=linus.walleij@linaro.org \
--cc=arm@kernel.org \
--cc=linux-arm-kernel@lists.infradead.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.