drivers: serial: stm32: add reinit after standby

When resuming from low power mode, if UART is disabled, this means that
we come from a mode that reset the registers, so we redo a full init of
the driver.

Signed-off-by: Guillaume Gautier <guillaume.gautier-ext@st.com>
This commit is contained in:
Guillaume Gautier 2023-12-08 14:11:53 +01:00 committed by Carles Cufí
commit 0792a85f77

View file

@ -2081,17 +2081,26 @@ static int uart_stm32_pm_action(const struct device *dev,
switch (action) {
case PM_DEVICE_ACTION_RESUME:
/* Set pins to active state */
err = pinctrl_apply_state(config->pcfg, PINCTRL_STATE_DEFAULT);
if (err < 0) {
return err;
}
/* When exiting low power mode, check whether UART is enabled.
* If not, it means we are exiting Suspend to RAM mode (STM32
* Standby), and the driver need to be reinitialized
*/
if (LL_USART_IsEnabled(config->usart)) {
/* Set pins to active state */
err = pinctrl_apply_state(config->pcfg, PINCTRL_STATE_DEFAULT);
if (err < 0) {
return err;
}
/* enable clock */
err = clock_control_on(data->clock, (clock_control_subsys_t)&config->pclken[0]);
if (err != 0) {
LOG_ERR("Could not enable (LP)UART clock");
return err;
/* enable clock */
err = clock_control_on(data->clock,
(clock_control_subsys_t)&config->pclken[0]);
if (err != 0) {
LOG_ERR("Could not enable (LP)UART clock");
return err;
}
} else {
uart_stm32_init(dev);
}
break;
case PM_DEVICE_ACTION_SUSPEND: