pm: device: move device busy APIs to pm subsystem

The following device busy APIs:

- device_busy_set()
- device_busy_clear()
- device_busy_check()
- device_any_busy_check()

were used for device PM, so they have been moved to the pm subsystem.
This means they are now prefixed with `pm_` and are defined in
`pm/device.h`.

If device PM is not enabled dummy functions are now provided that do
nothing or return `-ENOSYS`, meaning that the functionality is not
available.

Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>

drivers/i2c/i2c_dw.c

@@ -425,15 +425,15 @@ static int i2c_dw_transfer(const struct device *dev,
 	 * While waiting at device_sync_sem, kernel can switch to idle
 	 * task which in turn can call pm_system_suspend() hook of Power
 	 * Management App (PMA).
-	 * device_busy_set() call here, would indicate to PMA that it should not
+	 * pm_device_busy_set() call here, would indicate to PMA that it should
-	 * execute PM policies that would turn off this ip block, causing an
+	 * not execute PM policies that would turn off this ip block, causing an
 	 * ongoing hw transaction to be left in an inconsistent state.
 	 * Note : This is just a sample to show a possible use of the API, it is
 	 * upto the driver expert to see, if he actually needs it here, or
 	 * somewhere else, or not needed as the driver's suspend()/resume()
 	 * can handle everything
 	 */
-	device_busy_set(dev);
+	pm_device_busy_set(dev);
 
 		/* Process all the messages */
 	while (msg_left > 0) {
@@ -493,7 +493,7 @@ static int i2c_dw_transfer(const struct device *dev,
 		msg_left--;
 	}
 
-	device_busy_clear(dev);
+	pm_device_busy_clear(dev);
 
 	dw->state = I2C_DW_STATE_READY;
 

drivers/sensor/bmp388/bmp388.c

@@ -353,7 +353,7 @@ static int bmp388_sample_fetch(const struct device *dev,
 	}
 #endif
 
-	device_busy_set(dev);
+	pm_device_busy_set(dev);
 
 	/* Wait for status to indicate that data is ready. */
 	raw[0] = 0U;
@@ -382,7 +382,7 @@ static int bmp388_sample_fetch(const struct device *dev,
 	bmp388->sample.comp_temp = 0;
 
 error:
-	device_busy_clear(dev);
+	pm_device_busy_clear(dev);
 	return ret;
 }
 

drivers/serial/uart_cc13xx_cc26xx.c

@@ -241,7 +241,7 @@ static void uart_cc13xx_cc26xx_irq_tx_enable(const struct device *dev)
 		 * to transmit using the uart, hence we should no longer go
 		 * into standby.
 		 *
-		 * Instead of using device_busy_set(), which currently does
+		 * Instead of using pm_device_busy_set(), which currently does
 		 * not impact the PM policy, we specifically disable the
 		 * standby mode instead, since it is the power state that
 		 * would interfere with a transfer.

drivers/serial/uart_nrfx_uart.c

@@ -833,7 +833,7 @@ static void uart_nrfx_irq_tx_enable(const struct device *dev)
 	/* Indicate that this device started a transaction that should not be
 	 * interrupted by putting the SoC into the deep sleep mode.
 	 */
-	device_busy_set(dev);
+	pm_device_busy_set(dev);
 
 	/* Activate the transmitter. */
 	nrf_uart_task_trigger(uart0_addr, NRF_UART_TASK_STARTTX);
@@ -956,7 +956,7 @@ static void uart_nrfx_isr(const struct device *dev)
 		/* The transaction is over. It is okay to enter the deep sleep
 		 * mode if needed.
 		 */
-		device_busy_clear(dev);
+		pm_device_busy_clear(dev);
 
 		disable_tx_irq = false;
 

drivers/spi/spi_dw.c

@@ -344,8 +344,8 @@ static int transceive(const struct device *dev,
 	spi_context_lock(&spi->ctx, asynchronous, signal, config);
 
 #ifdef CONFIG_PM_DEVICE
-	if (device_busy_check(dev) != (-EBUSY)) {
+	if (pm_device_busy_check(dev) != (-EBUSY)) {
-		device_busy_set(dev);
+		pm_device_busy_set(dev);
 	}
 #endif /* CONFIG_PM_DEVICE */
 
@@ -434,7 +434,7 @@ static int transceive(const struct device *dev,
 out:
 	spi_context_release(&spi->ctx, ret);
 
-	device_busy_clear(dev);
+	pm_device_busy_clear(dev);
 
 	return ret;
 }

include/device.h

@@ -612,52 +612,6 @@ static inline bool device_is_ready(const struct device *dev)
 	return device_usable_check(dev) == 0;
 }
 
-/**
- * @brief Indicate that the device is in the middle of a transaction
- *
- * Called by a device driver to indicate that it is in the middle of a
- * transaction.
- *
- * @param dev Pointer to device structure of the driver instance.
- */
-void device_busy_set(const struct device *dev);
-
-/**
- * @brief Indicate that the device has completed its transaction
- *
- * Called by a device driver to indicate the end of a transaction.
- *
- * @param dev Pointer to device structure of the driver instance.
- */
-void device_busy_clear(const struct device *dev);
-
-#ifdef CONFIG_PM_DEVICE
-/**
- * @brief Check if any device is in the middle of a transaction
- *
- * Called by an application to see if any device is in the middle
- * of a critical transaction that cannot be interrupted.
- *
- * @retval 0 if no device is busy
- * @retval -EBUSY if any device is busy
- */
-int device_any_busy_check(void);
-
-/**
- * @brief Check if a specific device is in the middle of a transaction
- *
- * Called by an application to see if a particular device is in the
- * middle of a critical transaction that cannot be interrupted.
- *
- * @param chk_dev Pointer to device structure of the specific device driver
- * the caller is interested in.
- * @retval 0 if the device is not busy
- * @retval -EBUSY if the device is busy
- */
-int device_busy_check(const struct device *chk_dev);
-
-#endif
-
 /**
  * @}
  */

include/pm/device.h

@@ -133,6 +133,56 @@ int pm_device_state_set(const struct device *dev,
 int pm_device_state_get(const struct device *dev,
 			enum pm_device_state *device_power_state);
 
+#ifdef CONFIG_PM_DEVICE
+/**
+ * @brief Indicate that the device is in the middle of a transaction
+ *
+ * Called by a device driver to indicate that it is in the middle of a
+ * transaction.
+ *
+ * @param dev Pointer to device structure of the driver instance.
+ */
+void pm_device_busy_set(const struct device *dev);
+
+/**
+ * @brief Indicate that the device has completed its transaction
+ *
+ * Called by a device driver to indicate the end of a transaction.
+ *
+ * @param dev Pointer to device structure of the driver instance.
+ */
+void pm_device_busy_clear(const struct device *dev);
+
+/**
+ * @brief Check if any device is in the middle of a transaction
+ *
+ * Called by an application to see if any device is in the middle
+ * of a critical transaction that cannot be interrupted.
+ *
+ * @retval 0 if no device is busy
+ * @retval -EBUSY if any device is busy
+ */
+int pm_device_any_busy_check(void);
+
+/**
+ * @brief Check if a specific device is in the middle of a transaction
+ *
+ * Called by an application to see if a particular device is in the
+ * middle of a critical transaction that cannot be interrupted.
+ *
+ * @param chk_dev Pointer to device structure of the specific device driver
+ * the caller is interested in.
+ * @retval 0 if the device is not busy
+ * @retval -EBUSY if the device is busy
+ */
+int pm_device_busy_check(const struct device *chk_dev);
+#else
+static inline void pm_device_busy_set(const struct device *dev) {}
+static inline void pm_device_busy_clear(const struct device *dev) {}
+static inline int pm_device_any_busy_check(void) { return -ENOSYS; }
+static inline int pm_device_busy_check(const struct device *chk_dev) { return -ENOSYS; }
+#endif
+
 /** Alias for legacy use of device_pm_control_nop */
 #define device_pm_control_nop __DEPRECATED_MACRO NULL
 

kernel/device.c

@@ -195,50 +195,3 @@ int device_required_foreach(const struct device *dev,
 
 	return handle_count;
 }
-
-#ifdef CONFIG_PM_DEVICE
-int device_any_busy_check(void)
-{
-	const struct device *dev = __device_start;
-
-	while (dev < __device_end) {
-		if (atomic_test_bit(&dev->pm->atomic_flags,
-				    PM_DEVICE_ATOMIC_FLAGS_BUSY_BIT)) {
-			return -EBUSY;
-		}
-		++dev;
-	}
-
-	return 0;
-}
-
-int device_busy_check(const struct device *dev)
-{
-	if (atomic_test_bit(&dev->pm->atomic_flags,
-			    PM_DEVICE_ATOMIC_FLAGS_BUSY_BIT)) {
-		return -EBUSY;
-	}
-	return 0;
-}
-
-#endif
-
-void device_busy_set(const struct device *dev)
-{
-#ifdef CONFIG_PM_DEVICE
-	atomic_set_bit(&dev->pm->atomic_flags,
-		       PM_DEVICE_ATOMIC_FLAGS_BUSY_BIT);
-#else
-	ARG_UNUSED(dev);
-#endif
-}
-
-void device_busy_clear(const struct device *dev)
-{
-#ifdef CONFIG_PM_DEVICE
-	atomic_clear_bit(&dev->pm->atomic_flags,
-			 PM_DEVICE_ATOMIC_FLAGS_BUSY_BIT);
-#else
-	ARG_UNUSED(dev);
-#endif
-}

samples/boards/stm32/power_mgmt/blinky/src/main.c

@@ -24,7 +24,7 @@ void main(void)
 	printk("Device ready\n");
 
 	/* Don't let the system power off / low power this device */
-	device_busy_set(led.port);
+	pm_device_busy_set(led.port);
 
 	while (true) {
 		gpio_pin_configure_dt(&led, GPIO_OUTPUT_ACTIVE);

subsys/pm/device.c

@@ -10,7 +10,6 @@
 #include <device.h>
 #include <pm/policy.h>
 
-#if defined(CONFIG_PM)
 #define LOG_LEVEL CONFIG_PM_LOG_LEVEL /* From power module Kconfig */
 #include <logging/log.h>
 LOG_MODULE_DECLARE(power);
@@ -18,6 +17,7 @@ LOG_MODULE_DECLARE(power);
 extern const struct device __device_start[];
 extern const struct device __device_end[];
 
+#if defined(CONFIG_PM)
 extern const struct device *__pm_device_slots_start[];
 
 /* Number of devices successfully suspended. */
@@ -28,7 +28,7 @@ static bool should_suspend(const struct device *dev, enum pm_device_state state)
 	int rc;
 	enum pm_device_state current_state;
 
-	if (device_busy_check(dev) != 0) {
+	if (pm_device_busy_check(dev) != 0) {
 		return false;
 	}
 
@@ -149,3 +149,39 @@ int pm_device_state_get(const struct device *dev,
 	return dev->pm_control(dev, PM_DEVICE_STATE_GET,
 			       device_power_state);
 }
+
+int pm_device_any_busy_check(void)
+{
+	const struct device *dev = __device_start;
+
+	while (dev < __device_end) {
+		if (atomic_test_bit(&dev->pm->atomic_flags,
+				    PM_DEVICE_ATOMIC_FLAGS_BUSY_BIT)) {
+			return -EBUSY;
+		}
+		++dev;
+	}
+
+	return 0;
+}
+
+int pm_device_busy_check(const struct device *dev)
+{
+	if (atomic_test_bit(&dev->pm->atomic_flags,
+			    PM_DEVICE_ATOMIC_FLAGS_BUSY_BIT)) {
+		return -EBUSY;
+	}
+	return 0;
+}
+
+void pm_device_busy_set(const struct device *dev)
+{
+	atomic_set_bit(&dev->pm->atomic_flags,
+		       PM_DEVICE_ATOMIC_FLAGS_BUSY_BIT);
+}
+
+void pm_device_busy_clear(const struct device *dev)
+{
+	atomic_clear_bit(&dev->pm->atomic_flags,
+			 PM_DEVICE_ATOMIC_FLAGS_BUSY_BIT);
+}

tests/kernel/device/src/main.c

@@ -51,7 +51,7 @@ extern void test_mmio_device_map(void);
  *
  * @ingroup kernel_device_tests
  *
- * @see device_get_binding(), device_busy_set(), device_busy_clear(),
+ * @see device_get_binding(), pm_device_busy_set(), pm_device_busy_clear(),
  * DEVICE_DEFINE()
  */
 void test_dummy_device(void)
@@ -66,8 +66,8 @@ void test_dummy_device(void)
 	dev = device_get_binding(DUMMY_PORT_2);
 	zassert_false((dev == NULL), NULL);
 
-	device_busy_set(dev);
+	pm_device_busy_set(dev);
-	device_busy_clear(dev);
+	pm_device_busy_clear(dev);
 
 	/* device_get_binding() returns false for device object
 	 * with failed init.
@@ -283,8 +283,8 @@ static void test_enable_and_disable_automatic_runtime_pm(void)
  * enabled. It also checks if the device is in the middle of a transaction,
  * sets/clears busy status and validates status again.
  *
- * @see device_get_binding(), device_busy_set(), device_busy_clear(),
+ * @see device_get_binding(), pm_device_busy_set(), pm_device_busy_clear(),
- * device_busy_check(), device_any_busy_check(),
+ * pm_device_busy_check(), pm_device_any_busy_check(),
  * pm_device_state_set()
  */
 void test_dummy_device_pm(void)
@@ -296,22 +296,22 @@ void test_dummy_device_pm(void)
 	dev = device_get_binding(DUMMY_PORT_2);
 	zassert_false((dev == NULL), NULL);
 
-	busy = device_any_busy_check();
+	busy = pm_device_any_busy_check();
 	zassert_true((busy == 0), NULL);
 
 	/* Set device state to BUSY*/
-	device_busy_set(dev);
+	pm_device_busy_set(dev);
 
-	busy = device_any_busy_check();
+	busy = pm_device_any_busy_check();
 	zassert_false((busy == 0), NULL);
 
-	busy = device_busy_check(dev);
+	busy = pm_device_busy_check(dev);
 	zassert_false((busy == 0), NULL);
 
 	/* Clear device BUSY state*/
-	device_busy_clear(dev);
+	pm_device_busy_clear(dev);
 
-	busy = device_busy_check(dev);
+	busy = pm_device_busy_check(dev);
 	zassert_true((busy == 0), NULL);
 
 	test_build_suspend_device_list();