From: Maxime Ripard <maxime.ripard@bootlin.com>
To: Chen-Yu Tsai <wens@csie.org>
Cc: devicetree@vger.kernel.org,
Linus Walleij <linus.walleij@linaro.org>,
linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org,
linux-sunxi@googlegroups.com,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 1/9] pinctrl: sunxi: Support I/O bias voltage setting on A80
Date: Wed, 6 Feb 2019 13:17:18 +0100 [thread overview]
Message-ID: <20190206121718.3yqbirt5l3qwneco@flea> (raw)
In-Reply-To: <20190206033239.3619-2-wens@csie.org>
[-- Attachment #1.1: Type: text/plain, Size: 1412 bytes --]
On Wed, Feb 06, 2019 at 11:32:31AM +0800, Chen-Yu Tsai wrote:
> The A80 SoC has configuration registers for I/O bias voltage. Incorrect
> settings would make the affected peripherals inoperable in some cases,
> such as Ethernet RGMII signals biased at 2.5V with the settings still
> at 3.3V. However low speed signals such as MDIO on the same group of
> pins seem to be unaffected.
>
> Previously there was no way to know what the actual voltage used was,
> short of hard-coding a value in the device tree. With the new pin bank
> regulator supply support in place, the driver can now query the
> regulator for its voltage, and if it's valid (as opposed to being the
> dummy regulator), set the bias voltage setting accordingly.
>
> Add a quirk to denote the presence of the configuration registers, and
> a function to set the correct setting based on the voltage read back
> from the regulator.
>
> This is only done when the regulator is first acquired and enabled.
> While it would be nice to have a notifier on the regulator so that when
> the voltage changes, the driver can update the setting, in practice no
> board currently supports dynamic changing of the I/O voltages.
>
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Maxime
--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
[-- Attachment #1.2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]
[-- Attachment #2: Type: text/plain, Size: 176 bytes --]
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-02-06 12:17 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-06 3:32 [PATCH 0/9] ARM: sun9i: a80: Enable GMAC Chen-Yu Tsai
2019-02-06 3:32 ` [PATCH 1/9] pinctrl: sunxi: Support I/O bias voltage setting on A80 Chen-Yu Tsai
2019-02-06 8:14 ` Linus Walleij
2019-02-06 10:22 ` [linux-sunxi] " Chen-Yu Tsai
2019-02-06 12:17 ` Maxime Ripard [this message]
2019-02-11 8:20 ` Linus Walleij
2019-02-13 11:31 ` Chen-Yu Tsai
2019-02-06 3:32 ` [PATCH 2/9] ARM: dts: sun9i: a80-optimus: Add node for AXP809's unused dc1sw regulator Chen-Yu Tsai
2019-02-06 3:32 ` [PATCH 3/9] ARM: dts: sun9i: a80-optimus: Add GPIO pin-bank regulator supplies Chen-Yu Tsai
2019-02-06 3:32 ` [PATCH 4/9] ARM: dts: sun9i: cubieboard4: " Chen-Yu Tsai
2019-02-06 3:32 ` [PATCH 5/9] ARM: dts: sun9i: Add GMAC clock node Chen-Yu Tsai
2019-02-06 3:32 ` [PATCH 6/9] ARM: dts: sun9i: Add A80 GMAC gigabit ethernet controller node Chen-Yu Tsai
2019-02-06 3:32 ` [PATCH 7/9] ARM: dts: sun9i: Add A80 GMAC RGMII pinmux setting Chen-Yu Tsai
2019-02-06 3:32 ` [PATCH 8/9] ARM: dts: sun9i: a80-optimus: Enable GMAC Chen-Yu Tsai
2019-02-06 3:32 ` [PATCH 9/9] ARM: dts: sun9i: cubieboard4: " Chen-Yu Tsai
2019-02-06 12:16 ` [PATCH 0/9] ARM: sun9i: a80: " Maxime Ripard
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=20190206121718.3yqbirt5l3qwneco@flea \
--to=maxime.ripard@bootlin.com \
--cc=devicetree@vger.kernel.org \
--cc=linus.walleij@linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-gpio@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-sunxi@googlegroups.com \
--cc=wens@csie.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