pwm: stm32-lp: fix the check on arr and cmp registers update

[ Upstream commit 3066bc2d58 ]

The ARR (auto reload register) and CMP (compare) registers are
successively written. The status bits to check the update of these
registers are polled together with regmap_read_poll_timeout().
The condition to end the loop may become true, even if one of the
register isn't correctly updated.
So ensure both status bits are set before clearing them.

Fixes: e70a540b4e ("pwm: Add STM32 LPTimer PWM driver")
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Fabrice Gasnier 2022-11-23 14:36:52 +01:00 committed by Greg Kroah-Hartman
parent 094ffaf50b
commit 9a0af7cb1c
1 changed files with 1 additions and 1 deletions

View File

@ -127,7 +127,7 @@ static int stm32_pwm_lp_apply(struct pwm_chip *chip, struct pwm_device *pwm,
/* ensure CMP & ARR registers are properly written */
ret = regmap_read_poll_timeout(priv->regmap, STM32_LPTIM_ISR, val,
(val & STM32_LPTIM_CMPOK_ARROK),
(val & STM32_LPTIM_CMPOK_ARROK) == STM32_LPTIM_CMPOK_ARROK,
100, 1000);
if (ret) {
dev_err(priv->chip.dev, "ARR/CMP registers write issue\n");