soundwire: Handle multiple master instances in a stream

For each SoundWire stream operation, we need to parse master
list and operate upon all master runtime.

This is a preparatory patch to do the boilerplate conversion
of stream handling from single master runtime to handle a
list of master runtime. The code to support bank switch for
multiple master instances is added in the next patch.
Signed-off-by: Sanyog Kale <sanyog.r.kale@intel.com>
Signed-off-by: Shreyas NC <shreyas.nc@intel.com>
Acked-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/soundwire/stream.c

@@ -681,18 +681,22 @@ static int sdw_bank_switch(struct sdw_bus *bus)
 
 static int do_bank_switch(struct sdw_stream_runtime *stream)
 {
-	struct sdw_master_runtime *m_rt = stream->m_rt;
+	struct sdw_master_runtime *m_rt = NULL;
 	const struct sdw_master_ops *ops;
-	struct sdw_bus *bus = m_rt->bus;
+	struct sdw_bus *bus = NULL;
 	int ret = 0;
 
+
+	list_for_each_entry(m_rt, &stream->master_list, stream_node) {
+		bus = m_rt->bus;
 		ops = bus->ops;
 
 		/* Pre-bank switch */
 		if (ops->pre_bank_switch) {
 			ret = ops->pre_bank_switch(bus);
 			if (ret < 0) {
-			dev_err(bus->dev, "Pre bank switch op failed: %d", ret);
+				dev_err(bus->dev,
+					"Pre bank switch op failed: %d", ret);
 				return ret;
 			}
 		}
@@ -703,6 +707,11 @@ static int do_bank_switch(struct sdw_stream_runtime *stream)
 			dev_err(bus->dev, "Bank switch failed: %d", ret);
 			return ret;
 		}
+	}
+
+	list_for_each_entry(m_rt, &stream->master_list, stream_node) {
+		bus = m_rt->bus;
+		ops = bus->ops;
 
 		/* Post-bank switch */
 		if (ops->post_bank_switch) {
@@ -712,6 +721,7 @@ static int do_bank_switch(struct sdw_stream_runtime *stream)
 					"Post bank switch op failed: %d", ret);
 			}
 		}
+	}
 
 	return ret;
 }
@@ -754,6 +764,21 @@ struct sdw_stream_runtime *sdw_alloc_stream(char *stream_name)
 }
 EXPORT_SYMBOL(sdw_alloc_stream);
 
+static struct sdw_master_runtime
+*sdw_find_master_rt(struct sdw_bus *bus,
+			struct sdw_stream_runtime *stream)
+{
+	struct sdw_master_runtime *m_rt = NULL;
+
+	/* Retrieve Bus handle if already available */
+	list_for_each_entry(m_rt, &stream->master_list, stream_node) {
+		if (m_rt->bus == bus)
+			return m_rt;
+	}
+
+	return NULL;
+}
+
 /**
  * sdw_alloc_master_rt() - Allocates and initialize Master runtime handle
  *
@@ -770,12 +795,11 @@ static struct sdw_master_runtime
 {
 	struct sdw_master_runtime *m_rt;
 
-	m_rt = stream->m_rt;
-
 	/*
 	 * check if Master is already allocated (as a result of Slave adding
 	 * it first), if so skip allocation and go to configure
 	 */
+	m_rt = sdw_find_master_rt(bus, stream);
 	if (m_rt)
 		goto stream_config;
 
@@ -786,7 +810,7 @@ static struct sdw_master_runtime
 	/* Initialization of Master runtime handle */
 	INIT_LIST_HEAD(&m_rt->port_list);
 	INIT_LIST_HEAD(&m_rt->slave_rt_list);
-	stream->m_rt = m_rt;
+	list_add_tail(&m_rt->stream_node, &stream->master_list);
 
 	list_add_tail(&m_rt->bus_node, &bus->m_rt_list);
 
@@ -844,19 +868,23 @@ static void sdw_slave_port_release(struct sdw_bus *bus,
 			struct sdw_stream_runtime *stream)
 {
 	struct sdw_port_runtime *p_rt, *_p_rt;
-	struct sdw_master_runtime *m_rt = stream->m_rt;
+	struct sdw_master_runtime *m_rt;
 	struct sdw_slave_runtime *s_rt;
 
+	list_for_each_entry(m_rt, &stream->master_list, stream_node) {
 		list_for_each_entry(s_rt, &m_rt->slave_rt_list, m_rt_node) {
+
 			if (s_rt->slave != slave)
 				continue;
 
 			list_for_each_entry_safe(p_rt, _p_rt,
 					&s_rt->port_list, port_node) {
+
 				list_del(&p_rt->port_node);
 				kfree(p_rt);
 			}
 		}
+	}
 }
 
 /**
@@ -871,8 +899,9 @@ static void sdw_release_slave_stream(struct sdw_slave *slave,
 			struct sdw_stream_runtime *stream)
 {
 	struct sdw_slave_runtime *s_rt, *_s_rt;
-	struct sdw_master_runtime *m_rt = stream->m_rt;
+	struct sdw_master_runtime *m_rt;
 
+	list_for_each_entry(m_rt, &stream->master_list, stream_node) {
 		/* Retrieve Slave runtime handle */
 		list_for_each_entry_safe(s_rt, _s_rt,
 					&m_rt->slave_rt_list, m_rt_node) {
@@ -883,11 +912,13 @@ static void sdw_release_slave_stream(struct sdw_slave *slave,
 				return;
 			}
 		}
+	}
 }
 
 /**
  * sdw_release_master_stream() - Free Master runtime handle
  *
+ * @m_rt: Master runtime node
  * @stream: Stream runtime handle.
  *
  * This function is to be called with bus_lock held
@@ -895,9 +926,9 @@ static void sdw_release_slave_stream(struct sdw_slave *slave,
  * handle. If this is called first then sdw_release_slave_stream() will have
  * no effect as Slave(s) runtime handle would already be freed up.
  */
-static void sdw_release_master_stream(struct sdw_stream_runtime *stream)
+static void sdw_release_master_stream(struct sdw_master_runtime *m_rt,
+			struct sdw_stream_runtime *stream)
 {
-	struct sdw_master_runtime *m_rt = stream->m_rt;
 	struct sdw_slave_runtime *s_rt, *_s_rt;
 
 	list_for_each_entry_safe(s_rt, _s_rt, &m_rt->slave_rt_list, m_rt_node) {
@@ -905,7 +936,9 @@ static void sdw_release_master_stream(struct sdw_stream_runtime *stream)
 		sdw_release_slave_stream(s_rt->slave, stream);
 	}
 
+	list_del(&m_rt->stream_node);
 	list_del(&m_rt->bus_node);
+	kfree(m_rt);
 }
 
 /**
@@ -919,13 +952,22 @@ static void sdw_release_master_stream(struct sdw_stream_runtime *stream)
 int sdw_stream_remove_master(struct sdw_bus *bus,
 		struct sdw_stream_runtime *stream)
 {
+	struct sdw_master_runtime *m_rt, *_m_rt;
+
 	mutex_lock(&bus->bus_lock);
 
-	sdw_release_master_stream(stream);
-	sdw_master_port_release(bus, stream->m_rt);
+	list_for_each_entry_safe(m_rt, _m_rt,
+			&stream->master_list, stream_node) {
+
+		if (m_rt->bus != bus)
+			continue;
+
+		sdw_master_port_release(bus, m_rt);
+		sdw_release_master_stream(m_rt, stream);
+	}
+
+	if (list_empty(&stream->master_list))
 		stream->state = SDW_STREAM_RELEASED;
-	kfree(stream->m_rt);
-	stream->m_rt = NULL;
 
 	mutex_unlock(&bus->bus_lock);
 
@@ -1128,7 +1170,7 @@ int sdw_stream_add_master(struct sdw_bus *bus,
 	goto unlock;
 
 stream_error:
-	sdw_release_master_stream(stream);
+	sdw_release_master_stream(m_rt, stream);
 unlock:
 	mutex_unlock(&bus->bus_lock);
 	return ret;
@@ -1206,7 +1248,7 @@ int sdw_stream_add_slave(struct sdw_slave *slave,
 	 * we hit error so cleanup the stream, release all Slave(s) and
 	 * Master runtime
 	 */
-	sdw_release_master_stream(stream);
+	sdw_release_master_stream(m_rt, stream);
 error:
 	mutex_unlock(&slave->bus->bus_lock);
 	return ret;
@@ -1275,6 +1317,8 @@ static void sdw_acquire_bus_lock(struct sdw_stream_runtime *stream)
  * @stream: SoundWire stream
  *
  * Release the previously held bus_lock after reconfiguring the bus.
+ * NOTE: This function is called from SoundWire stream ops and is
+ * expected that a global lock is held before releasing bus_lock.
  */
 static void sdw_release_bus_lock(struct sdw_stream_runtime *stream)
 {
@@ -1290,12 +1334,15 @@ static void sdw_release_bus_lock(struct sdw_stream_runtime *stream)
 
 static int _sdw_prepare_stream(struct sdw_stream_runtime *stream)
 {
-	struct sdw_master_runtime *m_rt = stream->m_rt;
-	struct sdw_bus *bus = m_rt->bus;
+	struct sdw_master_runtime *m_rt = NULL;
+	struct sdw_bus *bus = NULL;
 	struct sdw_master_prop *prop = NULL;
 	struct sdw_bus_params params;
 	int ret;
 
+	/* Prepare  Master(s) and Slave(s) port(s) associated with stream */
+	list_for_each_entry(m_rt, &stream->master_list, stream_node) {
+		bus = m_rt->bus;
 		prop = &bus->prop;
 		memcpy(&params, &bus->params, sizeof(params));
 
@@ -1317,12 +1364,17 @@ static int _sdw_prepare_stream(struct sdw_stream_runtime *stream)
 			goto restore_params;
 		}
 
+	}
+
 	ret = do_bank_switch(stream);
 	if (ret < 0) {
 		dev_err(bus->dev, "Bank switch failed: %d", ret);
 		goto restore_params;
 	}
 
+	list_for_each_entry(m_rt, &stream->master_list, stream_node) {
+		bus = m_rt->bus;
+
 		/* Prepare port(s) on the new clock configuration */
 		ret = sdw_prep_deprep_ports(m_rt, true);
 		if (ret < 0) {
@@ -1330,6 +1382,7 @@ static int _sdw_prepare_stream(struct sdw_stream_runtime *stream)
 					ret);
 			return ret;
 		}
+	}
 
 	stream->state = SDW_STREAM_PREPARED;
 
@@ -1356,23 +1409,27 @@ int sdw_prepare_stream(struct sdw_stream_runtime *stream)
 		return -EINVAL;
 	}
 
-	mutex_lock(&stream->m_rt->bus->bus_lock);
+	sdw_acquire_bus_lock(stream);
 
 	ret = _sdw_prepare_stream(stream);
 	if (ret < 0)
 		pr_err("Prepare for stream:%s failed: %d", stream->name, ret);
 
-	mutex_unlock(&stream->m_rt->bus->bus_lock);
+	sdw_release_bus_lock(stream);
 	return ret;
 }
 EXPORT_SYMBOL(sdw_prepare_stream);
 
 static int _sdw_enable_stream(struct sdw_stream_runtime *stream)
 {
-	struct sdw_master_runtime *m_rt = stream->m_rt;
-	struct sdw_bus *bus = m_rt->bus;
+	struct sdw_master_runtime *m_rt = NULL;
+	struct sdw_bus *bus = NULL;
 	int ret;
 
+	/* Enable Master(s) and Slave(s) port(s) associated with stream */
+	list_for_each_entry(m_rt, &stream->master_list, stream_node) {
+		bus = m_rt->bus;
+
 		/* Program params */
 		ret = sdw_program_params(bus);
 		if (ret < 0) {
@@ -1386,6 +1443,7 @@ static int _sdw_enable_stream(struct sdw_stream_runtime *stream)
 			dev_err(bus->dev, "Enable port(s) failed ret: %d", ret);
 			return ret;
 		}
+	}
 
 	ret = do_bank_switch(stream);
 	if (ret < 0) {
@@ -1413,38 +1471,43 @@ int sdw_enable_stream(struct sdw_stream_runtime *stream)
 		return -EINVAL;
 	}
 
-	mutex_lock(&stream->m_rt->bus->bus_lock);
+	sdw_acquire_bus_lock(stream);
 
 	ret = _sdw_enable_stream(stream);
 	if (ret < 0)
 		pr_err("Enable for stream:%s failed: %d", stream->name, ret);
 
-	mutex_unlock(&stream->m_rt->bus->bus_lock);
+	sdw_release_bus_lock(stream);
 	return ret;
 }
 EXPORT_SYMBOL(sdw_enable_stream);
 
 static int _sdw_disable_stream(struct sdw_stream_runtime *stream)
 {
-	struct sdw_master_runtime *m_rt = stream->m_rt;
-	struct sdw_bus *bus = m_rt->bus;
+	struct sdw_master_runtime *m_rt = NULL;
+	struct sdw_bus *bus = NULL;
 	int ret;
 
+	list_for_each_entry(m_rt, &stream->master_list, stream_node) {
+		bus = m_rt->bus;
 		/* Disable port(s) */
 		ret = sdw_enable_disable_ports(m_rt, false);
 		if (ret < 0) {
 			dev_err(bus->dev, "Disable port(s) failed: %d", ret);
 			return ret;
 		}
-
+	}
 	stream->state = SDW_STREAM_DISABLED;
 
+	list_for_each_entry(m_rt, &stream->master_list, stream_node) {
+		bus = m_rt->bus;
 		/* Program params */
 		ret = sdw_program_params(bus);
 		if (ret < 0) {
 			dev_err(bus->dev, "Program params failed: %d", ret);
 			return ret;
 		}
+	}
 
 	return do_bank_switch(stream);
 }
@@ -1465,23 +1528,25 @@ int sdw_disable_stream(struct sdw_stream_runtime *stream)
 		return -EINVAL;
 	}
 
-	mutex_lock(&stream->m_rt->bus->bus_lock);
+	sdw_acquire_bus_lock(stream);
 
 	ret = _sdw_disable_stream(stream);
 	if (ret < 0)
 		pr_err("Disable for stream:%s failed: %d", stream->name, ret);
 
-	mutex_unlock(&stream->m_rt->bus->bus_lock);
+	sdw_release_bus_lock(stream);
 	return ret;
 }
 EXPORT_SYMBOL(sdw_disable_stream);
 
 static int _sdw_deprepare_stream(struct sdw_stream_runtime *stream)
 {
-	struct sdw_master_runtime *m_rt = stream->m_rt;
-	struct sdw_bus *bus = m_rt->bus;
+	struct sdw_master_runtime *m_rt = NULL;
+	struct sdw_bus *bus = NULL;
 	int ret = 0;
 
+	list_for_each_entry(m_rt, &stream->master_list, stream_node) {
+		bus = m_rt->bus;
 		/* De-prepare port(s) */
 		ret = sdw_prep_deprep_ports(m_rt, false);
 		if (ret < 0) {
@@ -1489,8 +1554,6 @@ static int _sdw_deprepare_stream(struct sdw_stream_runtime *stream)
 			return ret;
 		}
 
-	stream->state = SDW_STREAM_DEPREPARED;
-
 		/* TODO: Update this during Device-Device support */
 		bus->params.bandwidth -= m_rt->stream->params.rate *
 			m_rt->ch_count * m_rt->stream->params.bps;
@@ -1502,6 +1565,9 @@ static int _sdw_deprepare_stream(struct sdw_stream_runtime *stream)
 			return ret;
 		}
 
+	}
+
+	stream->state = SDW_STREAM_DEPREPARED;
 	return do_bank_switch(stream);
 }
 
@@ -1521,13 +1587,12 @@ int sdw_deprepare_stream(struct sdw_stream_runtime *stream)
 		return -EINVAL;
 	}
 
-	mutex_lock(&stream->m_rt->bus->bus_lock);
-
+	sdw_acquire_bus_lock(stream);
 	ret = _sdw_deprepare_stream(stream);
 	if (ret < 0)
 		pr_err("De-prepare for stream:%d failed: %d", ret, ret);
 
-	mutex_unlock(&stream->m_rt->bus->bus_lock);
+	sdw_release_bus_lock(stream);
 	return ret;
 }
 EXPORT_SYMBOL(sdw_deprepare_stream);

include/linux/soundwire/sdw.h

@@ -768,7 +768,6 @@ struct sdw_stream_params {
  * @params: Stream parameters
  * @state: Current state of the stream
  * @type: Stream type PCM or PDM
- * @m_rt: Master runtime
  * @master_list: List of Master runtime(s) in this stream.
  * master_list can contain only one m_rt per Master instance
  * for a stream
@@ -778,7 +777,6 @@ struct sdw_stream_runtime {
 	struct sdw_stream_params params;
 	enum sdw_stream_state state;
 	enum sdw_stream_type type;
-	struct sdw_master_runtime *m_rt;
 	struct list_head master_list;
 };