[nrf fromlist] drivers: adc: nrfx_saadc: implement PM device runtime

The NRFX SAADC device driver needs to implement PM DEVICE for it
to work with power domains, which is required for some SoCs. Inline
PM device runtime "self get/put" pm has been implemented for the
normal sync read API.

Upstream PR #: 96711

Signed-off-by: Bjarki Arge Andreasen <[email protected]>

Author: bjarki-andreasen

drivers/adc/adc_nrfx_saadc.c

@@ -12,6 +12,8 @@
 #include <zephyr/linker/devicetree_regions.h>
 #include <zephyr/logging/log.h>
 #include <zephyr/irq.h>
+#include <zephyr/pm/device.h>
+#include <zephyr/pm/device_runtime.h>
 #include <dmm.h>
 
 LOG_MODULE_REGISTER(adc_nrfx_saadc, CONFIG_ADC_LOG_LEVEL);
@@ -724,10 +726,19 @@ static int adc_nrfx_read(const struct device *dev,
 {
 	int error;
 
+	error = pm_device_runtime_get(dev);
+	if (error) {
+		return error;
+	}
+
 	adc_context_lock(&m_data.ctx, false, NULL);
 	error = start_read(dev, sequence);
 	adc_context_release(&m_data.ctx, error);
 
+	if (pm_device_runtime_put(dev)) {
+		LOG_ERR("PM put failed");
+	}
+
 	return error;
 }
 
@@ -777,6 +788,13 @@ static void event_handler(const nrfx_saadc_evt_t *event)
 	}
 }
 
+static int saadc_pm_handler(const struct device *dev, enum pm_device_action action)
+{
+	ARG_UNUSED(dev);
+	ARG_UNUSED(action);
+	return 0;
+}
+
 static int init_saadc(const struct device *dev)
 {
 	nrfx_err_t err;
@@ -794,7 +812,7 @@ static int init_saadc(const struct device *dev)
 
 	adc_context_unlock_unconditionally(&m_data.ctx);
 
-	return 0;
+	return pm_device_driver_init(dev, saadc_pm_handler);
 }
 
 static DEVICE_API(adc, adc_nrfx_driver_api) = {
@@ -837,5 +855,7 @@ DT_FOREACH_CHILD(DT_DRV_INST(0), VALIDATE_CHANNEL_CONFIG)
 
 NRF_DT_CHECK_NODE_HAS_REQUIRED_MEMORY_REGIONS(DT_DRV_INST(0));
 
-DEVICE_DT_INST_DEFINE(0, init_saadc, NULL, NULL, NULL, POST_KERNEL,
-		      CONFIG_ADC_INIT_PRIORITY, &adc_nrfx_driver_api);
+PM_DEVICE_DT_INST_DEFINE(0, saadc_pm_handler);
+DEVICE_DT_INST_DEFINE(0, init_saadc, PM_DEVICE_DT_INST_GET(0), NULL,
+		      NULL, POST_KERNEL, CONFIG_ADC_INIT_PRIORITY,
+		      &adc_nrfx_driver_api);