Messages in this thread Patch in this message | | | Date | Wed, 04 Mar 2020 13:57:39 +0000 | From | Mark Brown <> | Subject | Applied "regulator: stm32-vrefbuf: fix a possible overshoot when re-enabling" to the regulator tree |
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The patch
regulator: stm32-vrefbuf: fix a possible overshoot when re-enabling
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 02fbabd5f4ed182d2c616e49309f5a3efd9ec671 Mon Sep 17 00:00:00 2001 From: Fabrice Gasnier <fabrice.gasnier@st.com> Date: Wed, 4 Mar 2020 09:55:32 +0100 Subject: [PATCH] regulator: stm32-vrefbuf: fix a possible overshoot when re-enabling
There maybe an overshoot, when disabling, then re-enabling vrefbuf too quickly. VREFBUF is used by ADC/DAC on some boards. When re-enabling too quickly, an overshoot on the reference voltage make the conversions inaccurate for a short period of time. - Don't put the VREFBUF in HiZ when disabling, to force an active discharge. - Enforce a 1ms OFF/ON delay
Fixes: 0cdbf481e927 ("regulator: Add support for stm32-vrefbuf")
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Message-Id: <1583312132-20932-1-git-send-email-fabrice.gasnier@st.com> Signed-off-by: Mark Brown <broonie@kernel.org> --- drivers/regulator/stm32-vrefbuf.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/regulator/stm32-vrefbuf.c b/drivers/regulator/stm32-vrefbuf.c index bdfaf7edb75a..992bc18101ef 100644 --- a/drivers/regulator/stm32-vrefbuf.c +++ b/drivers/regulator/stm32-vrefbuf.c @@ -88,7 +88,7 @@ static int stm32_vrefbuf_disable(struct regulator_dev *rdev) } val = readl_relaxed(priv->base + STM32_VREFBUF_CSR); - val = (val & ~STM32_ENVR) | STM32_HIZ; + val &= ~STM32_ENVR; writel_relaxed(val, priv->base + STM32_VREFBUF_CSR); pm_runtime_mark_last_busy(priv->dev); @@ -175,6 +175,7 @@ static const struct regulator_desc stm32_vrefbuf_regu = { .volt_table = stm32_vrefbuf_voltages, .n_voltages = ARRAY_SIZE(stm32_vrefbuf_voltages), .ops = &stm32_vrefbuf_volt_ops, + .off_on_delay = 1000, .type = REGULATOR_VOLTAGE, .owner = THIS_MODULE, }; -- 2.20.1
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