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| author | Fabrice Gasnier <fabrice.gasnier@st.com> | 2020-03-04 11:55:32 +0300 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2020-03-04 16:57:28 +0300 |
| commit | 02fbabd5f4ed182d2c616e49309f5a3efd9ec671 (patch) | |
| tree | 50bae0825dfaca838567cea2d6cec1f24107e9b3 /drivers/regulator/stm32-vrefbuf.c | |
| parent | a5b0cda136f4f420a8e24e50d19dfcef2f81df2e (diff) | |
| download | linux-02fbabd5f4ed182d2c616e49309f5a3efd9ec671.tar.xz | |
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>
Diffstat (limited to 'drivers/regulator/stm32-vrefbuf.c')
| -rw-r--r-- | drivers/regulator/stm32-vrefbuf.c | 3 |
1 files changed, 2 insertions, 1 deletions
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, }; |