Messages in this thread Patch in this message | | | From | Mark Brown <> | Subject | Applied "dt-bindings: mfd: axp20x: Add software based soft_start for AXP209 LDO3" to the regulator tree | Date | Thu, 13 Dec 2018 18:11:37 +0000 (GMT) |
| |
The patch
dt-bindings: mfd: axp20x: Add software based soft_start for AXP209 LDO3
has been applied to the regulator tree at
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git
All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying to this mail.
Thanks, Mark
From eb51c6eb9775d5e7ef810327dbc84bb0d15f72b5 Mon Sep 17 00:00:00 2001 From: Olliver Schinagl <oliver@schinagl.nl> Date: Tue, 11 Dec 2018 17:17:09 +0200 Subject: [PATCH] dt-bindings: mfd: axp20x: Add software based soft_start for AXP209 LDO3
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> Signed-off-by: Mark Brown <broonie@kernel.org> --- Documentation/devicetree/bindings/mfd/axp20x.txt | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/Documentation/devicetree/bindings/mfd/axp20x.txt b/Documentation/devicetree/bindings/mfd/axp20x.txt index c6266052d23f..2af4ff95d6bc 100644 --- a/Documentation/devicetree/bindings/mfd/axp20x.txt +++ b/Documentation/devicetree/bindings/mfd/axp20x.txt @@ -37,6 +37,9 @@ more information: - regulator-ramp-delay: sets the ramp up delay in uV/us AXP20x/DCDC2: 1600, 800 AXP20x/LDO3: 1600, 800 +- regulator-soft-start: enable the output at the lowest possible voltage and + only then set the desired voltage + AXP20x/LDO3: software-based implementation Optional properties: - x-powers,dcdc-freq: defines the work frequency of DC-DC in KHz -- 2.19.0.rc2
| |