drivers: tacho: mchp: low power feature enabled

Updated Tacho driver to support low power feature.

Signed-off-by: Manimaran A <manimaran.a@microchip.com>

drivers/sensor/mchp_tach_xec/tach_mchp_xec.c

@@ -21,6 +21,11 @@
 #include <zephyr/sys/sys_io.h>
 #include <zephyr/logging/log.h>
 
+#include <zephyr/pm/device.h>
+#ifdef CONFIG_PM_DEVICE
+#include <zephyr/pm/policy.h>
+#endif
+
 LOG_MODULE_REGISTER(tach_xec, CONFIG_SENSOR_LOG_LEVEL);
 
 struct tach_xec_config {
@@ -33,6 +38,7 @@ struct tach_xec_config {
 };
 
 struct tach_xec_data {
+	uint32_t control;
 	uint16_t count;
 };
 
@@ -52,6 +58,9 @@ int tach_xec_sample_fetch(const struct device *dev, enum sensor_channel chan)
 	struct tach_regs * const tach = cfg->regs;
 	uint8_t poll_count = 0;
 
+#ifdef CONFIG_PM_DEVICE
+	pm_policy_state_lock_get(PM_STATE_SUSPEND_TO_IDLE, PM_ALL_SUBSTATES);
+#endif
 	while (poll_count < PIN_STS_TIMEOUT) {
 		/* See whether internal counter is already latched */
 		if (tach->STATUS & MCHP_TACH_STS_CNT_RDY) {
@@ -65,7 +74,9 @@ int tach_xec_sample_fetch(const struct device *dev, enum sensor_channel chan)
 		/* Allow other threads to run while we sleep */
 		k_usleep(USEC_PER_MSEC);
 	}
-
+#ifdef CONFIG_PM_DEVICE
+	pm_policy_state_lock_put(PM_STATE_SUSPEND_TO_IDLE, PM_ALL_SUBSTATES);
+#endif
 	if (poll_count == PIN_STS_TIMEOUT) {
 		return -EINVAL;
 	}
@@ -117,6 +128,36 @@ static void tach_xec_sleep_clr(const struct device *dev)
 #endif
 }
 
+#ifdef CONFIG_PM_DEVICE
+static int tach_xec_pm_action(const struct device *dev, enum pm_device_action action)
+{
+	const struct tach_xec_config * const cfg = dev->config;
+	struct tach_xec_data * const data = dev->data;
+	struct tach_regs * const tach = cfg->regs;
+	int ret = 0;
+
+	switch (action) {
+	case PM_DEVICE_ACTION_RESUME:
+		if (data->control & MCHP_TACH_CTRL_EN) {
+			tach->CONTROL |= MCHP_TACH_CTRL_EN;
+			data->control &= (~MCHP_TACH_CTRL_EN);
+		}
+	break;
+	case PM_DEVICE_ACTION_SUSPEND:
+		if (tach->CONTROL & MCHP_TACH_CTRL_EN) {
+			/* Take a backup */
+			data->control = tach->CONTROL;
+			tach->CONTROL &= (~MCHP_TACH_CTRL_EN);
+		}
+	break;
+	default:
+		ret = -ENOTSUP;
+	}
+
+	return ret;
+}
+#endif /* CONFIG_PM_DEVICE */
+
 static int tach_xec_init(const struct device *dev)
 {
 	const struct tach_xec_config * const cfg = dev->config;
@@ -161,9 +202,11 @@ static const struct sensor_driver_api tach_xec_driver_api = {
 									\
 	XEC_TACH_CONFIG(id);						\
 									\
+	PM_DEVICE_DT_INST_DEFINE(id, tach_xec_pm_action);		\
+									\
 	SENSOR_DEVICE_DT_INST_DEFINE(id,				\
 			    tach_xec_init,				\
-			    NULL,					\
+			    PM_DEVICE_DT_INST_GET(id),			\
 			    &tach_xec_data_##id,			\
 			    &tach_xec_config_##id,			\
 			    POST_KERNEL,				\