drivers: i2c: stm32: Disable suspend to idle during transaction

Suspend-to-idle stops I2C module clocks, which must remain active during transaction Signed-off-by: Petr Hlineny <[email protected]>
zephyrproject-rtos · Feb 2, 2024 · a97c825 · a97c825
1 parent bc1a988
commit a97c825
Showing 1 changed file with 6 additions and 4 deletions.
diff --git a/drivers/i2c/i2c_ll_stm32.c b/drivers/i2c/i2c_ll_stm32.c
@@ -9,6 +9,7 @@
 #include <zephyr/drivers/clock_control.h>
 #include <zephyr/pm/device.h>
 #include <zephyr/pm/device_runtime.h>
+#include <zephyr/pm/policy.h>
 #include <zephyr/sys/util.h>
 #include <zephyr/kernel.h>
 #include <soc.h>
@@ -173,10 +174,11 @@ static int i2c_stm32_transfer(const struct device *dev, struct i2c_msg *msg,
 	/* Prevent driver from being suspended by PM until I2C transaction is complete */
 #ifdef CONFIG_PM_DEVICE_RUNTIME
 	(void)pm_device_runtime_get(dev);
-#else
-	pm_device_busy_set(dev);
 #endif
 
+	/* Prevent the clocks to be stopped during the i2c transaction */
+	pm_policy_state_lock_get(PM_STATE_SUSPEND_TO_IDLE, PM_ALL_SUBSTATES);
+
 	current = msg;
 
 	while (num_msgs > 0) {
@@ -194,10 +196,10 @@ static int i2c_stm32_transfer(const struct device *dev, struct i2c_msg *msg,
 		num_msgs--;
 	}
 
+	pm_policy_state_lock_put(PM_STATE_SUSPEND_TO_IDLE, PM_ALL_SUBSTATES);
+
 #ifdef CONFIG_PM_DEVICE_RUNTIME
 	(void)pm_device_runtime_put(dev);
-#else
-	pm_device_busy_clear(dev);
 #endif
 
 	k_sem_give(&data->bus_mutex);