Merge tag 'soundwire-4.20-rc1' of...

Merge tag 'soundwire-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/soundwire into char-misc-next

Vinod writes:

soundwire updates for 4.20-rc1

 - support for multi-link streaming
 - updates in intel driver for multi-link streaming
 - Update Vinod's email
 - Fix rst formatting

* tag 'soundwire-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/soundwire:
  Documentation: soundwire: fix stream.rst markup warnings
  soundwire: intel: Remove duplicate assignment
  MAINTAINERS: Update Vinod's email
  soundwire: intel: Fix uninitialized adev deref
  soundwire: intel: Add pre/post bank switch ops
  soundwire: keep track of Masters in a stream
  soundwire: Add support for multi link bank switch
  soundwire: Handle multiple master instances in a stream
  soundwire: Add support to lock across bus instances
  soundwire: Initialize completion for defer messages
  Documentation: soundwire: Add documentation for multi link

Documentation/driver-api/soundwire/stream.rst

@@ -101,6 +101,34 @@ interface. ::
 	+--------------------+                             |                |
 							   +----------------+
 
+Example 5: Stereo Stream with L and R channel is rendered by 2 Masters, each
+rendering one channel, and is received by two different Slaves, each
+receiving one channel. Both Masters and both Slaves are using single port. ::
+
+	+---------------+                    Clock Signal  +---------------+
+	|    Master     +----------------------------------+     Slave     |
+	|   Interface   |                                  |   Interface   |
+	|       1       |                                  |       1       |
+	|               |                     Data Signal  |               |
+	|       L       +----------------------------------+       L       |
+	|     (Data)    |     Data Direction               |     (Data)    |
+	+---------------+  +----------------------->       +---------------+
+
+	+---------------+                    Clock Signal  +---------------+
+	|    Master     +----------------------------------+     Slave     |
+	|   Interface   |                                  |   Interface   |
+	|       2       |                                  |       2       |
+	|               |                     Data Signal  |               |
+	|       R       +----------------------------------+       R       |
+	|     (Data)    |     Data Direction               |     (Data)    |
+	+---------------+  +----------------------->       +---------------+
+
+Note: In multi-link cases like above, to lock, one would acquire a global
+lock and then go on locking bus instances. But, in this case the caller
+framework(ASoC DPCM) guarantees that stream operations on a card are
+always serialized. So, there is no race condition and hence no need for
+global lock.
+
 SoundWire Stream Management flow
 ================================
 
@@ -174,6 +202,7 @@ per stream. From ASoC DPCM framework, this stream state maybe linked to
 .startup() operation.
 
   .. code-block:: c
+
   int sdw_alloc_stream(char * stream_name);
 
 
@@ -200,6 +229,7 @@ only be invoked once by respective Master(s) and Slave(s). From ASoC DPCM
 framework, this stream state is linked to .hw_params() operation.
 
   .. code-block:: c
+
   int sdw_stream_add_master(struct sdw_bus * bus,
 		struct sdw_stream_config * stream_config,
 		struct sdw_ports_config * ports_config,
@@ -245,6 +275,7 @@ stream. From ASoC DPCM framework, this stream state is linked to
 .prepare() operation.
 
   .. code-block:: c
+
   int sdw_prepare_stream(struct sdw_stream_runtime * stream);
 
 
@@ -274,6 +305,7 @@ stream. From ASoC DPCM framework, this stream state is linked to
 .trigger() start operation.
 
   .. code-block:: c
+
   int sdw_enable_stream(struct sdw_stream_runtime * stream);
 
 SDW_STREAM_DISABLED
@@ -301,6 +333,7 @@ per stream. From ASoC DPCM framework, this stream state is linked to
 .trigger() stop operation.
 
   .. code-block:: c
+
   int sdw_disable_stream(struct sdw_stream_runtime * stream);
 
 
@@ -325,6 +358,7 @@ per stream. From ASoC DPCM framework, this stream state is linked to
 .trigger() stop operation.
 
   .. code-block:: c
+
   int sdw_deprepare_stream(struct sdw_stream_runtime * stream);
 
 
@@ -349,6 +383,7 @@ all the Master(s) and Slave(s) associated with stream. From ASoC DPCM
 framework, this stream state is linked to .hw_free() operation.
 
   .. code-block:: c
+
   int sdw_stream_remove_master(struct sdw_bus * bus,
 		struct sdw_stream_runtime * stream);
   int sdw_stream_remove_slave(struct sdw_slave * slave,
@@ -361,6 +396,7 @@ stream assigned as part of ALLOCATED state.
 In .shutdown() the data structure maintaining stream state are freed up.
 
   .. code-block:: c
+
   void sdw_release_stream(struct sdw_stream_runtime * stream);
 
 Not Supported

MAINTAINERS

@@ -13619,7 +13619,7 @@ F:	sound/soc/
 F:	include/sound/soc*
 
 SOUNDWIRE SUBSYSTEM
-M:	Vinod Koul <vinod.koul@intel.com>
+M:	Vinod Koul <vkoul@kernel.org>
 M:	Sanyog Kale <sanyog.r.kale@intel.com>
 R:	Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
 L:	alsa-devel@alsa-project.org (moderated for non-subscribers)

drivers/soundwire/bus.c

@@ -35,6 +35,11 @@ int sdw_add_bus_master(struct sdw_bus *bus)
 	INIT_LIST_HEAD(&bus->slaves);
 	INIT_LIST_HEAD(&bus->m_rt_list);
 
+	/*
+	 * Initialize multi_link flag
+	 * TODO: populate this flag by reading property from FW node
+	 */
+	bus->multi_link = false;
 	if (bus->ops->read_prop) {
 		ret = bus->ops->read_prop(bus);
 		if (ret < 0) {
@@ -175,6 +180,7 @@ static inline int do_transfer_defer(struct sdw_bus *bus,
 
 	defer->msg = msg;
 	defer->length = msg->len;
+	init_completion(&defer->complete);
 
 	for (i = 0; i <= retry; i++) {
 		resp = bus->ops->xfer_msg_defer(bus, msg, defer);

drivers/soundwire/bus.h

@@ -4,6 +4,8 @@
 #ifndef __SDW_BUS_H
 #define __SDW_BUS_H
 
+#define DEFAULT_BANK_SWITCH_TIMEOUT 3000
+
 #if IS_ENABLED(CONFIG_ACPI)
 int sdw_acpi_find_slaves(struct sdw_bus *bus);
 #else
@@ -99,6 +101,7 @@ struct sdw_slave_runtime {
  * this stream, can be zero.
  * @slave_rt_list: Slave runtime list
  * @port_list: List of Master Ports configured for this stream, can be zero.
+ * @stream_node: sdw_stream_runtime master_list node
  * @bus_node: sdw_bus m_rt_list node
  */
 struct sdw_master_runtime {
@@ -108,6 +111,7 @@ struct sdw_master_runtime {
 	unsigned int ch_count;
 	struct list_head slave_rt_list;
 	struct list_head port_list;
+	struct list_head stream_node;
 	struct list_head bus_node;
 };
 

drivers/soundwire/intel.c

@@ -397,6 +397,69 @@ static int intel_config_stream(struct sdw_intel *sdw,
 	return -EIO;
 }
 
+/*
+ * bank switch routines
+ */
+
+static int intel_pre_bank_switch(struct sdw_bus *bus)
+{
+	struct sdw_cdns *cdns = bus_to_cdns(bus);
+	struct sdw_intel *sdw = cdns_to_intel(cdns);
+	void __iomem *shim = sdw->res->shim;
+	int sync_reg;
+
+	/* Write to register only for multi-link */
+	if (!bus->multi_link)
+		return 0;
+
+	/* Read SYNC register */
+	sync_reg = intel_readl(shim, SDW_SHIM_SYNC);
+	sync_reg |= SDW_SHIM_SYNC_CMDSYNC << sdw->instance;
+	intel_writel(shim, SDW_SHIM_SYNC, sync_reg);
+
+	return 0;
+}
+
+static int intel_post_bank_switch(struct sdw_bus *bus)
+{
+	struct sdw_cdns *cdns = bus_to_cdns(bus);
+	struct sdw_intel *sdw = cdns_to_intel(cdns);
+	void __iomem *shim = sdw->res->shim;
+	int sync_reg, ret;
+
+	/* Write to register only for multi-link */
+	if (!bus->multi_link)
+		return 0;
+
+	/* Read SYNC register */
+	sync_reg = intel_readl(shim, SDW_SHIM_SYNC);
+
+	/*
+	 * post_bank_switch() ops is called from the bus in loop for
+	 * all the Masters in the steam with the expectation that
+	 * we trigger the bankswitch for the only first Master in the list
+	 * and do nothing for the other Masters
+	 *
+	 * So, set the SYNCGO bit only if CMDSYNC bit is set for any Master.
+	 */
+	if (!(sync_reg & SDW_SHIM_SYNC_CMDSYNC_MASK))
+		return 0;
+
+	/*
+	 * Set SyncGO bit to synchronously trigger a bank switch for
+	 * all the masters. A write to SYNCGO bit clears CMDSYNC bit for all
+	 * the Masters.
+	 */
+	sync_reg |= SDW_SHIM_SYNC_SYNCGO;
+
+	ret = intel_clear_bit(shim, SDW_SHIM_SYNC, sync_reg,
+					SDW_SHIM_SYNC_SYNCGO);
+	if (ret < 0)
+		dev_err(sdw->cdns.dev, "Post bank switch failed: %d", ret);
+
+	return ret;
+}
+
 /*
  * DAI routines
  */
@@ -750,6 +813,8 @@ static struct sdw_master_ops sdw_intel_ops = {
 	.xfer_msg_defer = cdns_xfer_msg_defer,
 	.reset_page_addr = cdns_reset_page_addr,
 	.set_bus_conf = cdns_bus_conf,
+	.pre_bank_switch = intel_pre_bank_switch,
+	.post_bank_switch = intel_post_bank_switch,
 };
 
 /*
@@ -780,9 +845,6 @@ static int intel_probe(struct platform_device *pdev)
 	sdw_intel_ops.read_prop = intel_prop_read;
 	sdw->cdns.bus.ops = &sdw_intel_ops;
 
-	sdw_intel_ops.read_prop = intel_prop_read;
-	sdw->cdns.bus.ops = &sdw_intel_ops;
-
 	platform_set_drvdata(pdev, sdw);
 
 	ret = sdw_add_bus_master(&sdw->cdns.bus);

drivers/soundwire/intel_init.c

@@ -151,7 +151,7 @@ static acpi_status sdw_intel_acpi_cb(acpi_handle handle, u32 level,
 	struct acpi_device *adev;
 
 	if (acpi_bus_get_device(handle, &adev)) {
-		dev_err(&adev->dev, "Couldn't find ACPI handle\n");
+		pr_err("%s: Couldn't find ACPI handle\n", __func__);
 		return AE_NOT_FOUND;
 	}
 

include/linux/soundwire/sdw.h

@@ -678,6 +678,9 @@ struct sdw_master_ops {
  * @defer_msg: Defer message
  * @clk_stop_timeout: Clock stop timeout computed
  * @bank_switch_timeout: Bank switch timeout computed
+ * @multi_link: Store bus property that indicates if multi links
+ * are supported. This flag is populated by drivers after reading
+ * appropriate firmware (ACPI/DT).
  */
 struct sdw_bus {
 	struct device *dev;
@@ -694,6 +697,7 @@ struct sdw_bus {
 	struct sdw_defer defer_msg;
 	unsigned int clk_stop_timeout;
 	u32 bank_switch_timeout;
+	bool multi_link;
 };
 
 int sdw_add_bus_master(struct sdw_bus *bus);
@@ -768,14 +772,18 @@ 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
+ * @m_rt_count: Count of Master runtime(s) in this stream
  */
 struct sdw_stream_runtime {
 	char *name;
 	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;
+	int m_rt_count;
 };
 
 struct sdw_stream_runtime *sdw_alloc_stream(char *stream_name);