From: Lee Jones <lee.jones@linaro.org>
To: Priit Laes <plaes@plaes.org>
Cc: Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>, Chen-Yu Tsai <wens@csie.org>,
Maxime Ripard <maxime.ripard@bootlin.com>,
Liam Girdwood <lgirdwood@gmail.com>,
Mark Brown <broonie@kernel.org>,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
Olliver Schinagl <oliver@schinagl.nl>,
linux-sunxi <linux-sunxi@googlegroups.com>
Subject: Re: [PATCH v2 5/8] dt-bindings: mfd: axp20x: Add software based soft_start for AXP209 LDO3
Date: Fri, 21 Dec 2018 08:40:10 +0000 [thread overview]
Message-ID: <20181221084010.GR4497@dell> (raw)
In-Reply-To: <25e67fe9b5397aa5f11bdd7026e4ae6be51dd18b.1544512919.git-series.plaes@plaes.org>
On Tue, 11 Dec 2018, Priit Laes wrote:
> From: Olliver Schinagl <oliver@schinagl.nl>
>
> In the past, there have been words on various lists that if LDO3 is
> disabled in u-boot, but enabled in the DTS, the axp209 driver would
> fail to continue/hang. Several enable/disable patches have been
> issues to devicetree's in both the kernel and u-boot to address
> this issue.
>
> What really happened however, was that the AXP209 shuts down without
> a notice and without setting an interrupt. This is caused when LDO3
> gets overloaded, for example with large capacitors on the LDO3 output.
>
> Normally, we would expect that AXP209 would source 200 mA as per
> datasheet and set and trigger an interrupt when being overloaded.
> For some reason however, this does not happen.
>
> As a work-around, implement software-based 'regulator-soft-start'
> property for AXP209 LDO3 regulator, which is used to first bring up
> the LDO3 to the lowest possible voltage and then enable the LDO.
>
> After that, we can set the requested voltage as usual.
>
> Combining this setting with the regulator-ramp-delay allows LDO3 to
> come up slowly and staggered, potentially reducing overall inrush current.
>
> Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>
> Signed-off-by: Priit Laes <plaes@plaes.org>
> ---
> Documentation/devicetree/bindings/mfd/axp20x.txt | 3 +++
> 1 file changed, 3 insertions(+)
For my own reference:
Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org>
--
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
next prev parent reply other threads:[~2018-12-21 8:40 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-11 15:17 [PATCH v2 0/8] regulator: axp20x: Stop AXP209 from crashing when enabling LDO3 Priit Laes
2018-12-11 15:17 ` [PATCH v2 1/8] mfd: axp20x: name voltage ramping define properly Priit Laes
2018-12-21 8:39 ` Lee Jones
2018-12-21 8:42 ` [linux-sunxi] " Priit Laes
2018-12-21 9:26 ` Lee Jones
2018-12-21 9:28 ` Priit Laes
2018-12-21 9:57 ` Lee Jones
2018-12-11 15:17 ` [PATCH v2 2/8] regulator: axp20x: add support for set_ramp_delay for AXP209 Priit Laes
2018-12-11 15:17 ` [PATCH v2 3/8] dt-bindings: mfd: axp20x: add support for regulator-ramp-delay " Priit Laes
2018-12-11 15:17 ` [PATCH v2 4/8] regulator: axp20x: add software based soft_start for AXP209 LDO3 Priit Laes
2018-12-11 15:17 ` [PATCH v2 5/8] dt-bindings: mfd: axp20x: Add " Priit Laes
2018-12-21 8:40 ` Lee Jones [this message]
2018-12-11 15:17 ` [PATCH v2 6/8] regulator: dts: enable soft-start and ramp delay for the OLinuXino Lime2 Priit Laes
2018-12-11 15:17 ` [PATCH v2 7/8] mfd: axp20x: Clean up included headers Priit Laes
2018-12-11 15:17 ` [PATCH v2 8/8] mfd: axp20x: use explicit bit defines Priit Laes
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=20181221084010.GR4497@dell \
--to=lee.jones@linaro.org \
--cc=broonie@kernel.org \
--cc=devicetree@vger.kernel.org \
--cc=lgirdwood@gmail.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-sunxi@googlegroups.com \
--cc=mark.rutland@arm.com \
--cc=maxime.ripard@bootlin.com \
--cc=oliver@schinagl.nl \
--cc=plaes@plaes.org \
--cc=robh+dt@kernel.org \
--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;
as well as URLs for NNTP newsgroup(s).