Soundwire: Use check pm runtime status with pm_runtime_suspended()

Documentation/driver-api/soundwire/stream.rst

@@ -156,22 +156,27 @@ Below shows the SoundWire stream states and state transition diagram. ::
 	+-----------+     +------------+     +----------+     +----------+
 	| ALLOCATED +---->| CONFIGURED +---->| PREPARED +---->| ENABLED  |
 	|   STATE   |     |    STATE   |     |  STATE   |     |  STATE   |
-	+-----------+     +------------+     +----------+     +----+-----+
-	                                                           ^
-	                                                           |
-	                                                           |
-	                                                           v
-	         +----------+           +------------+        +----+-----+
+	+-----------+     +------------+     +---+--+---+     +----+-----+
+	                                         ^  ^              ^
+				                 |  |              |
+				               __|  |___________   |
+				              |                 |  |
+	                                      v                 |  v
+	         +----------+           +-----+------+        +-+--+-----+
 	         | RELEASED |<----------+ DEPREPARED |<-------+ DISABLED |
 	         |  STATE   |           |   STATE    |        |  STATE   |
 	         +----------+           +------------+        +----------+
 
-NOTE: State transition between prepare and deprepare is supported in Spec
-but not in the software (subsystem)
+NOTE: State transitions between ``SDW_STREAM_ENABLED`` and
+``SDW_STREAM_DISABLED`` are only relevant when then INFO_PAUSE flag is
+supported at the ALSA/ASoC level. Likewise the transition between
+``SDW_DISABLED_STATE`` and ``SDW_PREPARED_STATE`` depends on the
+INFO_RESUME flag.
 
-NOTE2: Stream state transition checks need to be handled by caller
-framework, for example ALSA/ASoC. No checks for stream transition exist in
-SoundWire subsystem.
+NOTE2: The framework implements basic state transition checks, but
+does not e.g. check if a transition from DISABLED to ENABLED is valid
+on a specific platform. Such tests need to be added at the ALSA/ASoC
+level.
 
 Stream State Operations
 -----------------------
@@ -246,6 +251,9 @@ SDW_STREAM_PREPARED
 
 Prepare state of stream. Operations performed before entering in this state:
 
+  (0) Steps 1 and 2 are omitted in the case of a resume operation,
+      where the bus bandwidth is known.
+
   (1) Bus parameters such as bandwidth, frame shape, clock frequency,
       are computed based on current stream as well as already active
       stream(s) on Bus. Re-computation is required to accommodate current
@@ -270,13 +278,15 @@ Prepare state of stream. Operations performed before entering in this state:
 After all above operations are successful, stream state is set to
 ``SDW_STREAM_PREPARED``.
 
-Bus implements below API for PREPARE state which needs to be called once per
-stream. From ASoC DPCM framework, this stream state is linked to
-.prepare() operation.
+Bus implements below API for PREPARE state which needs to be called
+once per stream. From ASoC DPCM framework, this stream state is linked
+to .prepare() operation. Since the .trigger() operations may not
+follow the .prepare(), a direct transitions from
+``SDW_STREAM_PREPARED`` to ``SDW_STREAM_DEPREPARED`` is allowed.
 
 .. code-block:: c
 
-  int sdw_prepare_stream(struct sdw_stream_runtime * stream);
+  int sdw_prepare_stream(struct sdw_stream_runtime * stream, bool resume);
 
 
 SDW_STREAM_ENABLED
@@ -332,6 +342,14 @@ Bus implements below API for DISABLED state which needs to be called once
 per stream. From ASoC DPCM framework, this stream state is linked to
 .trigger() stop operation.
 
+When the INFO_PAUSE flag is supported, a direct transition to
+``SDW_STREAM_ENABLED`` is allowed.
+
+For resume operations where ASoC will use the .prepare() callback, the
+stream can transition from ``SDW_STREAM_DISABLED`` to
+``SDW_STREAM_PREPARED``, with all required settings restored but
+without updating the bandwidth and bit allocation.
+
 .. code-block:: c
 
   int sdw_disable_stream(struct sdw_stream_runtime * stream);
@@ -353,9 +371,18 @@ state:
 After all above operations are successful, stream state is set to
 ``SDW_STREAM_DEPREPARED``.
 
-Bus implements below API for DEPREPARED state which needs to be called once
-per stream. From ASoC DPCM framework, this stream state is linked to
-.trigger() stop operation.
+Bus implements below API for DEPREPARED state which needs to be called
+once per stream. ALSA/ASoC do not have a concept of 'deprepare', and
+the mapping from this stream state to ALSA/ASoC operation may be
+implementation specific.
+
+When the INFO_PAUSE flag is supported, the stream state is linked to
+the .hw_free() operation - the stream is not deprepared on a
+TRIGGER_STOP.
+
+Other implementations may transition to the ``SDW_STREAM_DEPREPARED``
+state on TRIGGER_STOP, should they require a transition through the
+``SDW_STREAM_PREPARED`` state.
 
 .. code-block:: c
 

drivers/soundwire/Kconfig

@@ -24,11 +24,15 @@ config SOUNDWIRE_CADENCE
 config SOUNDWIRE_INTEL
 	tristate "Intel SoundWire Master driver"
 	select SOUNDWIRE_CADENCE
+	select SOUNDWIRE_GENERIC_ALLOCATION
 	depends on ACPI && SND_SOC
 	help
 	  SoundWire Intel Master driver.
 	  If you have an Intel platform which has a SoundWire Master then
 	  enable this config option to get the SoundWire support for that
 	  device.
 
+config SOUNDWIRE_GENERIC_ALLOCATION
+	tristate
+
 endif

drivers/soundwire/Makefile

@@ -2,11 +2,15 @@
 #
 # Makefile for soundwire core
 #
+ccflags-y += -DDEBUG
 
 #Bus Objs
 soundwire-bus-objs := bus_type.o bus.o master.o slave.o mipi_disco.o stream.o
 obj-$(CONFIG_SOUNDWIRE) += soundwire-bus.o
 
+soundwire-generic-allocation-objs := generic_bandwidth_allocation.o
+obj-$(CONFIG_SOUNDWIRE_GENERIC_ALLOCATION) += soundwire-generic-allocation.o
+
 ifdef CONFIG_DEBUG_FS
 soundwire-bus-objs += debugfs.o
 endif

drivers/soundwire/bus.c

@@ -30,6 +30,12 @@ int sdw_add_bus_master(struct sdw_bus *bus)
 		return -EINVAL;
 	}
 
+	if (!bus->compute_params) {
+		dev_err(bus->dev,
+			"Bandwidth allocation not configured, compute_parems no set\n");
+		return -EINVAL;
+	}
+
 	mutex_init(&bus->msg_lock);
 	mutex_init(&bus->bus_lock);
 	INIT_LIST_HEAD(&bus->slaves);
@@ -113,6 +119,8 @@ static int sdw_delete_slave(struct device *dev, void *data)
 	struct sdw_slave *slave = to_sdw_slave_device(dev);
 	struct sdw_bus *bus = slave->bus;
 
+	pm_runtime_disable(dev);
+
 	sdw_slave_debugfs_exit(slave);
 
 	mutex_lock(&bus->bus_lock);
@@ -492,27 +500,42 @@ static int sdw_get_device_num(struct sdw_slave *slave)
 static int sdw_assign_device_num(struct sdw_slave *slave)
 {
 	int ret, dev_num;
+	bool new_device = false;
+
+	dev_dbg(slave->bus->dev, "in %s\n", __func__);
+
+
+	dev_dbg(slave->bus->dev, "in %s\n", __func__);
 
 	/* check first if device number is assigned, if so reuse that */
 	if (!slave->dev_num) {
-		mutex_lock(&slave->bus->bus_lock);
-		dev_num = sdw_get_device_num(slave);
-		mutex_unlock(&slave->bus->bus_lock);
-		if (dev_num < 0) {
-			dev_err(slave->bus->dev, "Get dev_num failed: %d\n",
-				dev_num);
-			return dev_num;
+		if (!slave->dev_num_sticky) {
+			mutex_lock(&slave->bus->bus_lock);
+			dev_num = sdw_get_device_num(slave);
+			mutex_unlock(&slave->bus->bus_lock);
+			if (dev_num < 0) {
+				dev_err(slave->bus->dev, "Get dev_num failed: %d\n",
+					dev_num);
+				return dev_num;
+			}
+			slave->dev_num = dev_num;
+			slave->dev_num_sticky = dev_num;
+			new_device = true;
+		} else {
+			slave->dev_num = slave->dev_num_sticky;
 		}
-	} else {
+	}
+
+	if (!new_device)
 		dev_info(slave->bus->dev,
-			 "Slave already registered dev_num:%d\n",
+			 "Slave already registered, reusing dev_num:%d\n",
 			 slave->dev_num);
 
-		/* Clear the slave->dev_num to transfer message on device 0 */
-		dev_num = slave->dev_num;
-		slave->dev_num = 0;
-	}
+	/* Clear the slave->dev_num to transfer message on device 0 */
+	dev_num = slave->dev_num;
+	slave->dev_num = 0;
 
+	dev_dbg(slave->bus->dev, "in %s, writing dev_num %d\n", __func__, dev_num);
 	ret = sdw_write_no_pm(slave, SDW_SCP_DEVNUMBER, dev_num);
 	if (ret < 0) {
 		dev_err(&slave->dev, "Program device_num %d failed: %d\n",
@@ -521,7 +544,7 @@ static int sdw_assign_device_num(struct sdw_slave *slave)
 	}
 
 	/* After xfer of msg, restore dev_num */
-	slave->dev_num = dev_num;
+	slave->dev_num = slave->dev_num_sticky;
 
 	return 0;
 }
@@ -630,13 +653,35 @@ static int sdw_program_device_num(struct sdw_bus *bus)
 
 	} while (ret == 0 && count < (SDW_MAX_DEVICES * 2));
 
+	dev_err(bus->dev, "End of %s ret %d\n", __func__, ret);
+
 	return ret;
 }
 
 static void sdw_modify_slave_status(struct sdw_slave *slave,
 				    enum sdw_slave_status status)
 {
 	mutex_lock(&slave->bus->bus_lock);
+
+	dev_vdbg(&slave->dev,
+		 "%s: changing status slave %d status %d new status %d\n",
+		 __func__, slave->dev_num, slave->status, status);
+
+	if (status == SDW_SLAVE_UNATTACHED) {
+		dev_dbg(&slave->dev,
+			"%s: initializing completion for Slave %d\n",
+			__func__, slave->dev_num);
+
+		init_completion(&slave->enumeration_complete);
+		init_completion(&slave->initialization_complete);
+
+	} else if (status == SDW_SLAVE_ATTACHED) {
+		dev_dbg(&slave->dev,
+			"%s: signaling completion for Slave %d\n",
+			__func__, slave->dev_num);
+
+		complete(&slave->enumeration_complete);
+	}
 	slave->status = status;
 	mutex_unlock(&slave->bus->bus_lock);
 }
@@ -1032,8 +1077,29 @@ int sdw_handle_slave_status(struct sdw_bus *bus,
 {
 	enum sdw_slave_status prev_status;
 	struct sdw_slave *slave;
+	bool attached_initializing;
 	int i, ret = 0;
 
+	dev_dbg(bus->dev, "%s: start\n", __func__);
+
+	/* first check if any Slaves fell off the bus */
+	for (i = 1; i <= SDW_MAX_DEVICES; i++) {
+		mutex_lock(&bus->bus_lock);
+		if (test_bit(i, bus->assigned) == false) {
+			mutex_unlock(&bus->bus_lock);
+			continue;
+		}
+		mutex_unlock(&bus->bus_lock);
+
+		slave = sdw_get_slave(bus, i);
+		if (!slave)
+			continue;
+
+		if (status[i] == SDW_SLAVE_UNATTACHED &&
+		    slave->status != SDW_SLAVE_UNATTACHED)
+			sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
+	}
+
 	if (status[0] == SDW_SLAVE_ATTACHED) {
 		dev_dbg(bus->dev, "Slave attached, programming device number\n");
 		ret = sdw_program_device_num(bus);
@@ -1059,6 +1125,8 @@ int sdw_handle_slave_status(struct sdw_bus *bus,
 		if (!slave)
 			continue;
 
+		attached_initializing = false;
+
 		switch (status[i]) {
 		case SDW_SLAVE_UNATTACHED:
 			if (slave->status == SDW_SLAVE_UNATTACHED)
@@ -1076,14 +1144,19 @@ int sdw_handle_slave_status(struct sdw_bus *bus,
 			break;
 
 		case SDW_SLAVE_ATTACHED:
-			if (slave->status == SDW_SLAVE_ATTACHED)
+			if (slave->status == SDW_SLAVE_ATTACHED) {
+				dev_err(bus->dev, "Slave %d status attached, was already attached, ignoring\n", i);
 				break;
-
+			}
 			prev_status = slave->status;
 			sdw_modify_slave_status(slave, SDW_SLAVE_ATTACHED);
 
-			if (prev_status == SDW_SLAVE_ALERT)
+			if (prev_status == SDW_SLAVE_ALERT)  {
+				dev_err(bus->dev, "Slave %d status attached, was alert, ignoring\n", i);
 				break;
+			}
+
+			attached_initializing = true;
 
 			ret = sdw_initialize_slave(slave);
 			if (ret)
@@ -1099,12 +1172,48 @@ int sdw_handle_slave_status(struct sdw_bus *bus,
 			break;
 		}
 
+		dev_err(bus->dev, "Updating Slave %d status\n", i);
 		ret = sdw_update_slave_status(slave, status[i]);
 		if (ret)
 			dev_err(slave->bus->dev,
 				"Update Slave status failed:%d\n", ret);
+
+		if (attached_initializing)
+			complete(&slave->initialization_complete);
+
+		dev_err(bus->dev, "%s: Updating Slave %d status done\n",
+			__func__, i);
 	}
 
+	dev_dbg(bus->dev, "%s: end\n", __func__);
+
 	return ret;
 }
 EXPORT_SYMBOL(sdw_handle_slave_status);
+
+void sdw_clear_slave_status(struct sdw_bus *bus, u32 request)
+{
+	struct sdw_slave *slave;
+	int i;
+
+	/* Check all non-zero devices */
+	for (i = 1; i <= SDW_MAX_DEVICES; i++) {
+		mutex_lock(&bus->bus_lock);
+		if (test_bit(i, bus->assigned) == false) {
+			mutex_unlock(&bus->bus_lock);
+			continue;
+		}
+		mutex_unlock(&bus->bus_lock);
+
+		slave = sdw_get_slave(bus, i);
+		if (!slave)
+			continue;
+
+		if (slave->status != SDW_SLAVE_UNATTACHED)
+			sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
+
+		/* keep track of request, used in pm_runtime resume */
+		slave->unattach_request = request;
+	}
+}
+EXPORT_SYMBOL(sdw_clear_slave_status);