From: Torsten Duwe <duwe@lst.de>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH v3 6/9] regulator: Add support for ramp delay
Date: Mon, 18 Feb 2019 15:03:17 +0100 [thread overview]
Message-ID: <20190218140317.GB6623@lst.de> (raw)
In-Reply-To: <20190216094548.911-7-krzk@kernel.org>
On Sat, Feb 16, 2019 at 10:45:45AM +0100, Krzysztof Kozlowski wrote:
> Changing voltage and enabling regulator might require delays so the
> regulator stabilizes at expected level.
>
> Add support for "regulator-ramp-delay" binding which can introduce
> required time to both enabling the regulator and to changing the
> voltage.
I'm surprised that such a thing doesn't exist already.
> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
> --- a/doc/device-tree-bindings/regulator/regulator.txt
> +++ b/doc/device-tree-bindings/regulator/regulator.txt
> @@ -35,6 +35,7 @@ Optional properties:
> - regulator-max-microamp: a maximum allowed Current value
> - regulator-always-on: regulator should never be disabled
> - regulator-boot-on: enabled by bootloader/firmware
> +- regulator-ramp-delay: ramp delay for regulator (in uV/us)
I guess you mean s/V, not V/s; at least the code suggests so.
But my main point is: is the required delay always a linear
function of the voltage jump? Depending on the dampening and
load on the rail this could be an overshoot and settle, no?
So I suggest to make that an array with 2 elements: a fixed part
and a time per voltage change. Does that make sense?
Torsten
next prev parent reply other threads:[~2019-02-18 14:03 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-16 9:45 [U-Boot] [PATCH v3 0/9] arm: exynos: Fix reboot on Odroid HC1 Krzysztof Kozlowski
2019-02-16 9:45 ` [U-Boot] [PATCH v3 1/9] adc: exynos-adc: Fix wrong bit operation used to stop the ADC Krzysztof Kozlowski
2019-02-16 9:45 ` [U-Boot] [PATCH v3 2/9] power: regulator: s2mps11: Fix step for LDO27 and LDO35 Krzysztof Kozlowski
2019-02-16 9:45 ` [U-Boot] [PATCH v3 3/9] arm: exynos: Detect revision later, when all resources are ready Krzysztof Kozlowski
2019-02-17 22:34 ` Lukasz Majewski
2019-02-16 9:45 ` [U-Boot] [PATCH v3 4/9] arm: exynos: odroid-xu3: Display info late to have proper type Krzysztof Kozlowski
2019-02-16 9:45 ` [U-Boot] [PATCH v3 5/9] arm: exynos: Wait till ADC stabilizes before checking Odroid HC1 revision Krzysztof Kozlowski
2019-02-16 9:45 ` [U-Boot] [PATCH v3 6/9] regulator: Add support for ramp delay Krzysztof Kozlowski
2019-02-18 14:03 ` Torsten Duwe [this message]
2019-02-18 14:28 ` Krzysztof Kozlowski
2019-02-18 15:26 ` Torsten Duwe
2019-02-19 12:14 ` Krzysztof Kozlowski
2019-02-16 9:45 ` [U-Boot] [PATCH v3 7/9] power: regulator: s2mps11: Add enable delay Krzysztof Kozlowski
2019-02-16 9:45 ` [U-Boot] [PATCH v3 8/9] arm: dts: exynos: Add supply for ADC block to Odroid XU3 family Krzysztof Kozlowski
2019-02-16 9:45 ` [U-Boot] [PATCH v3 9/9] arm: dts: exynos: Add ramp delay property to LDO regulators " Krzysztof Kozlowski
2019-02-24 12:55 ` [U-Boot] [PATCH v3 0/9] arm: exynos: Fix reboot on Odroid HC1 Anand Moon
2019-03-05 10:16 ` Minkyu Kang
2019-03-05 19:54 ` Krzysztof Kozlowski
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