Merge tag 'soundwire-streaming' of...

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

Vinod writes:

soundwire streaming

This contains:
 - Support for SoundWire Streaming
 - Documentation updates for streaming
 - Cadence and Intel driver updates for streaming
 - ASoC API for programming soundwire stream

Documentation/driver-api/soundwire/error_handling.rst

+========================
+SoundWire Error Handling
+========================
+
+The SoundWire PHY was designed with care and errors on the bus are going to
+be very unlikely, and if they happen it should be limited to single bit
+errors. Examples of this design can be found in the synchronization
+mechanism (sync loss after two errors) and short CRCs used for the Bulk
+Register Access.
+
+The errors can be detected with multiple mechanisms:
+
+1. Bus clash or parity errors: This mechanism relies on low-level detectors
+   that are independent of the payload and usages, and they cover both control
+   and audio data. The current implementation only logs such errors.
+   Improvements could be invalidating an entire programming sequence and
+   restarting from a known position. In the case of such errors outside of a
+   control/command sequence, there is no concealment or recovery for audio
+   data enabled by the SoundWire protocol, the location of the error will also
+   impact its audibility (most-significant bits will be more impacted in PCM),
+   and after a number of such errors are detected the bus might be reset. Note
+   that bus clashes due to programming errors (two streams using the same bit
+   slots) or electrical issues during the transmit/receive transition cannot
+   be distinguished, although a recurring bus clash when audio is enabled is a
+   indication of a bus allocation issue. The interrupt mechanism can also help
+   identify Slaves which detected a Bus Clash or a Parity Error, but they may
+   not be responsible for the errors so resetting them individually is not a
+   viable recovery strategy.
+
+2. Command status: Each command is associated with a status, which only
+   covers transmission of the data between devices. The ACK status indicates
+   that the command was received and will be executed by the end of the
+   current frame. A NAK indicates that the command was in error and will not
+   be applied. In case of a bad programming (command sent to non-existent
+   Slave or to a non-implemented register) or electrical issue, no response
+   signals the command was ignored. Some Master implementations allow for a
+   command to be retransmitted several times.  If the retransmission fails,
+   backtracking and restarting the entire programming sequence might be a
+   solution. Alternatively some implementations might directly issue a bus
+   reset and re-enumerate all devices.
+
+3. Timeouts: In a number of cases such as ChannelPrepare or
+   ClockStopPrepare, the bus driver is supposed to poll a register field until
+   it transitions to a NotFinished value of zero. The MIPI SoundWire spec 1.1
+   does not define timeouts but the MIPI SoundWire DisCo document adds
+   recommendation on timeouts. If such configurations do not complete, the
+   driver will return a -ETIMEOUT. Such timeouts are symptoms of a faulty
+   Slave device and are likely impossible to recover from.
+
+Errors during global reconfiguration sequences are extremely difficult to
+handle:
+
+1. BankSwitch: An error during the last command issuing a BankSwitch is
+   difficult to backtrack from. Retransmitting the Bank Switch command may be
+   possible in a single segment setup, but this can lead to synchronization
+   problems when enabling multiple bus segments (a command with side effects
+   such as frame reconfiguration would be handled at different times). A global
+   hard-reset might be the best solution.
+
+Note that SoundWire does not provide a mechanism to detect illegal values
+written in valid registers. In a number of cases the standard even mentions
+that the Slave might behave in implementation-defined ways. The bus
+implementation does not provide a recovery mechanism for such errors, Slave
+or Master driver implementers are responsible for writing valid values in
+valid registers and implement additional range checking if needed.

Documentation/driver-api/soundwire/index.rst

@@ -6,6 +6,9 @@ SoundWire Documentation
    :maxdepth: 1
 
    summary
+   stream
+   error_handling
+   locking
 
 .. only::  subproject
 

Documentation/driver-api/soundwire/locking.rst

+=================
+SoundWire Locking
+=================
+
+This document explains locking mechanism of the SoundWire Bus. Bus uses
+following locks in order to avoid race conditions in Bus operations on
+shared resources.
+
+  - Bus lock
+
+  - Message lock
+
+Bus lock
+========
+
+SoundWire Bus lock is a mutex and is part of Bus data structure
+(sdw_bus) which is used for every Bus instance. This lock is used to
+serialize each of the following operations(s) within SoundWire Bus instance.
+
+  - Addition and removal of Slave(s), changing Slave status.
+
+  - Prepare, Enable, Disable and De-prepare stream operations.
+
+  - Access of Stream data structure.
+
+Message lock
+============
+
+SoundWire message transfer lock. This mutex is part of
+Bus data structure (sdw_bus). This lock is used to serialize the message
+transfers (read/write) within a SoundWire Bus instance.
+
+Below examples show how locks are acquired.
+
+Example 1
+---------
+
+Message transfer.
+
+  1. For every message transfer
+
+     a. Acquire Message lock.
+
+     b. Transfer message (Read/Write) to Slave1 or broadcast message on
+        Bus in case of bank switch.
+
+     c. Release Message lock ::
+
+	+----------+                    +---------+
+	|          |                    |         |
+	|   Bus    |                    | Master  |
+	|          |                    | Driver  |
+	|          |                    |         |
+	+----+-----+                    +----+----+
+	     |                               |
+	     |     bus->ops->xfer_msg()      |
+	     <-------------------------------+   a. Acquire Message lock
+	     |                               |   b. Transfer message
+	     |                               |
+	     +------------------------------->   c. Release Message lock
+	     |    return success/error       |   d. Return success/error
+	     |                               |
+	     +                               +
+
+Example 2
+---------
+
+Prepare operation.
+
+  1. Acquire lock for Bus instance associated with Master 1.
+
+  2. For every message transfer in Prepare operation
+
+     a. Acquire Message lock.
+
+     b. Transfer message (Read/Write) to Slave1 or broadcast message on
+        Bus in case of bank switch.
+
+     c. Release Message lock.
+
+  3. Release lock for Bus instance associated with Master 1 ::
+
+	+----------+                    +---------+
+	|          |                    |         |
+	|   Bus    |                    | Master  |
+	|          |                    | Driver  |
+	|          |                    |         |
+	+----+-----+                    +----+----+
+	     |                               |
+	     |    sdw_prepare_stream()       |
+	     <-------------------------------+   1. Acquire bus lock
+	     |                               |   2. Perform stream prepare
+	     |                               |
+	     |                               |
+	     |     bus->ops->xfer_msg()      |
+	     <-------------------------------+   a. Acquire Message lock
+	     |                               |   b. Transfer message
+	     |                               |
+	     +------------------------------->   c. Release Message lock
+	     |    return success/error       |   d. Return success/error
+	     |                               |
+	     |                               |
+	     |    return success/error       |   3. Release bus lock
+	     +------------------------------->   4. Return success/error
+	     |                               |
+	     +                               +

MAINTAINERS

@@ -13115,7 +13115,7 @@ F:	include/uapi/sound/
 F:	sound/
 
 SOUND - COMPRESSED AUDIO
-M:	Vinod Koul <vinod.koul@intel.com>
+M:	Vinod Koul <vkoul@kernel.org>
 L:	alsa-devel@alsa-project.org (moderated for non-subscribers)
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound.git
 S:	Supported

drivers/soundwire/Kconfig

@@ -27,7 +27,7 @@ config SOUNDWIRE_INTEL
 	tristate "Intel SoundWire Master driver"
 	select SOUNDWIRE_CADENCE
 	select SOUNDWIRE_BUS
-	depends on X86 && ACPI
+	depends on X86 && ACPI && SND_SOC
 	---help---
 	  SoundWire Intel Master driver.
 	  If you have an Intel platform which has a SoundWire Master then

drivers/soundwire/Makefile

@@ -3,7 +3,7 @@
 #
 
 #Bus Objs
-soundwire-bus-objs := bus_type.o bus.o slave.o mipi_disco.o
+soundwire-bus-objs := bus_type.o bus.o slave.o mipi_disco.o stream.o
 obj-$(CONFIG_SOUNDWIRE_BUS) += soundwire-bus.o
 
 #Cadence Objs

drivers/soundwire/bus.c

@@ -17,6 +17,7 @@
  */
 int sdw_add_bus_master(struct sdw_bus *bus)
 {
+	struct sdw_master_prop *prop = NULL;
 	int ret;
 
 	if (!bus->dev) {
@@ -32,6 +33,7 @@ int sdw_add_bus_master(struct sdw_bus *bus)
 	mutex_init(&bus->msg_lock);
 	mutex_init(&bus->bus_lock);
 	INIT_LIST_HEAD(&bus->slaves);
+	INIT_LIST_HEAD(&bus->m_rt_list);
 
 	if (bus->ops->read_prop) {
 		ret = bus->ops->read_prop(bus);
@@ -77,6 +79,21 @@ int sdw_add_bus_master(struct sdw_bus *bus)
 		return ret;
 	}
 
+	/*
+	 * Initialize clock values based on Master properties. The max
+	 * frequency is read from max_freq property. Current assumption
+	 * is that the bus will start at highest clock frequency when
+	 * powered on.
+	 *
+	 * Default active bank will be 0 as out of reset the Slaves have
+	 * to start with bank 0 (Table 40 of Spec)
+	 */
+	prop = &bus->prop;
+	bus->params.max_dr_freq = prop->max_freq * SDW_DOUBLE_RATE_FACTOR;
+	bus->params.curr_dr_freq = bus->params.max_dr_freq;
+	bus->params.curr_bank = SDW_BANK0;
+	bus->params.next_bank = SDW_BANK1;
+
 	return 0;
 }
 EXPORT_SYMBOL(sdw_add_bus_master);
@@ -576,6 +593,32 @@ static void sdw_modify_slave_status(struct sdw_slave *slave,
 	mutex_unlock(&slave->bus->bus_lock);
 }
 
+int sdw_configure_dpn_intr(struct sdw_slave *slave,
+			int port, bool enable, int mask)
+{
+	u32 addr;
+	int ret;
+	u8 val = 0;
+
+	addr = SDW_DPN_INTMASK(port);
+
+	/* Set/Clear port ready interrupt mask */
+	if (enable) {
+		val |= mask;
+		val |= SDW_DPN_INT_PORT_READY;
+	} else {
+		val &= ~(mask);
+		val &= ~SDW_DPN_INT_PORT_READY;
+	}
+
+	ret = sdw_update(slave, addr, (mask | SDW_DPN_INT_PORT_READY), val);
+	if (ret < 0)
+		dev_err(slave->bus->dev,
+				"SDW_DPN_INTMASK write failed:%d", val);
+
+	return ret;
+}
+
 static int sdw_initialize_slave(struct sdw_slave *slave)
 {
 	struct sdw_slave_prop *prop = &slave->prop;

drivers/soundwire/bus.h

@@ -45,6 +45,78 @@ struct sdw_msg {
 	bool page;
 };
 
+#define SDW_DOUBLE_RATE_FACTOR		2
+
+extern int rows[SDW_FRAME_ROWS];
+extern int cols[SDW_FRAME_COLS];
+
+/**
+ * sdw_port_runtime: Runtime port parameters for Master or Slave
+ *
+ * @num: Port number. For audio streams, valid port number ranges from
+ * [1,14]
+ * @ch_mask: Channel mask
+ * @transport_params: Transport parameters
+ * @port_params: Port parameters
+ * @port_node: List node for Master or Slave port_list
+ *
+ * SoundWire spec has no mention of ports for Master interface but the
+ * concept is logically extended.
+ */
+struct sdw_port_runtime {
+	int num;
+	int ch_mask;
+	struct sdw_transport_params transport_params;
+	struct sdw_port_params port_params;
+	struct list_head port_node;
+};
+
+/**
+ * sdw_slave_runtime: Runtime Stream parameters for Slave
+ *
+ * @slave: Slave handle
+ * @direction: Data direction for Slave
+ * @ch_count: Number of channels handled by the Slave for
+ * this stream
+ * @m_rt_node: sdw_master_runtime list node
+ * @port_list: List of Slave Ports configured for this stream
+ */
+struct sdw_slave_runtime {
+	struct sdw_slave *slave;
+	enum sdw_data_direction direction;
+	unsigned int ch_count;
+	struct list_head m_rt_node;
+	struct list_head port_list;
+};
+
+/**
+ * sdw_master_runtime: Runtime stream parameters for Master
+ *
+ * @bus: Bus handle
+ * @stream: Stream runtime handle
+ * @direction: Data direction for Master
+ * @ch_count: Number of channels handled by the Master for
+ * this stream, can be zero.
+ * @slave_rt_list: Slave runtime list
+ * @port_list: List of Master Ports configured for this stream, can be zero.
+ * @bus_node: sdw_bus m_rt_list node
+ */
+struct sdw_master_runtime {
+	struct sdw_bus *bus;
+	struct sdw_stream_runtime *stream;
+	enum sdw_data_direction direction;
+	unsigned int ch_count;
+	struct list_head slave_rt_list;
+	struct list_head port_list;
+	struct list_head bus_node;
+};
+
+struct sdw_dpn_prop *sdw_get_slave_dpn_prop(struct sdw_slave *slave,
+				enum sdw_data_direction direction,
+				unsigned int port_num);
+int sdw_configure_dpn_intr(struct sdw_slave *slave, int port,
+					bool enable, int mask);
+
 int sdw_transfer(struct sdw_bus *bus, struct sdw_msg *msg);
 int sdw_transfer_defer(struct sdw_bus *bus, struct sdw_msg *msg,
 				struct sdw_defer *defer);

drivers/soundwire/cadence_master.h

 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
 // Copyright(c) 2015-17 Intel Corporation.
+#include <sound/soc.h>
 
 #ifndef __SDW_CADENCE_H
 #define __SDW_CADENCE_H
 
+/**
+ * struct sdw_cdns_pdi: PDI (Physical Data Interface) instance
+ *
+ * @assigned: pdi assigned
+ * @num: pdi number
+ * @intel_alh_id: link identifier
+ * @l_ch_num: low channel for PDI
+ * @h_ch_num: high channel for PDI
+ * @ch_count: total channel count for PDI
+ * @dir: data direction
+ * @type: stream type, PDM or PCM
+ */
+struct sdw_cdns_pdi {
+	bool assigned;
+	int num;
+	int intel_alh_id;
+	int l_ch_num;
+	int h_ch_num;
+	int ch_count;
+	enum sdw_data_direction dir;
+	enum sdw_stream_type type;
+};
+
+/**
+ * struct sdw_cdns_port: Cadence port structure
+ *
+ * @num: port number
+ * @assigned: port assigned
+ * @ch: channel count
+ * @direction: data port direction
+ * @pdi: pdi for this port
+ */
+struct sdw_cdns_port {
+	unsigned int num;
+	bool assigned;
+	unsigned int ch;
+	enum sdw_data_direction direction;
+	struct sdw_cdns_pdi *pdi;
+};
+
+/**
+ * struct sdw_cdns_streams: Cadence stream data structure
+ *
+ * @num_bd: number of bidirectional streams
+ * @num_in: number of input streams
+ * @num_out: number of output streams
+ * @num_ch_bd: number of bidirectional stream channels
+ * @num_ch_bd: number of input stream channels
+ * @num_ch_bd: number of output stream channels
+ * @num_pdi: total number of PDIs
+ * @bd: bidirectional streams
+ * @in: input streams
+ * @out: output streams
+ */
+struct sdw_cdns_streams {
+	unsigned int num_bd;
+	unsigned int num_in;
+	unsigned int num_out;
+	unsigned int num_ch_bd;
+	unsigned int num_ch_in;
+	unsigned int num_ch_out;
+	unsigned int num_pdi;
+	struct sdw_cdns_pdi *bd;
+	struct sdw_cdns_pdi *in;
+	struct sdw_cdns_pdi *out;
+};
+
+/**
+ * struct sdw_cdns_stream_config: stream configuration
+ *
+ * @pcm_bd: number of bidirectional PCM streams supported
+ * @pcm_in: number of input PCM streams supported
+ * @pcm_out: number of output PCM streams supported
+ * @pdm_bd: number of bidirectional PDM streams supported
+ * @pdm_in: number of input PDM streams supported
+ * @pdm_out: number of output PDM streams supported
+ */
+struct sdw_cdns_stream_config {
+	unsigned int pcm_bd;
+	unsigned int pcm_in;
+	unsigned int pcm_out;
+	unsigned int pdm_bd;
+	unsigned int pdm_in;
+	unsigned int pdm_out;
+};
+
+/**
+ * struct sdw_cdns_dma_data: Cadence DMA data
+ *
+ * @name: SoundWire stream name
+ * @nr_ports: Number of ports
+ * @port: Ports
+ * @bus: Bus handle
+ * @stream_type: Stream type
+ * @link_id: Master link id
+ */
+struct sdw_cdns_dma_data {
+	char *name;
+	struct sdw_stream_runtime *stream;
+	int nr_ports;
+	struct sdw_cdns_port **port;
+	struct sdw_bus *bus;
+	enum sdw_stream_type stream_type;
+	int link_id;
+};
+
 /**
  * struct sdw_cdns - Cadence driver context
  * @dev: Linux device
@@ -12,6 +119,10 @@
  * @response_buf: SoundWire response buffer
  * @tx_complete: Tx completion
  * @defer: Defer pointer
+ * @ports: Data ports
+ * @num_ports: Total number of data ports
+ * @pcm: PCM streams
+ * @pdm: PDM streams
  * @registers: Cadence registers
  * @link_up: Link status
  * @msg_count: Messages sent on bus
@@ -25,6 +136,12 @@ struct sdw_cdns {
 	struct completion tx_complete;
 	struct sdw_defer *defer;
 
+	struct sdw_cdns_port *ports;
+	int num_ports;
+
+	struct sdw_cdns_streams pcm;
+	struct sdw_cdns_streams pdm;
+
 	void __iomem *registers;
 
 	bool link_up;
@@ -42,7 +159,41 @@ irqreturn_t sdw_cdns_irq(int irq, void *dev_id);
 irqreturn_t sdw_cdns_thread(int irq, void *dev_id);
 
 int sdw_cdns_init(struct sdw_cdns *cdns);
+int sdw_cdns_pdi_init(struct sdw_cdns *cdns,
+			struct sdw_cdns_stream_config config);
 int sdw_cdns_enable_interrupt(struct sdw_cdns *cdns);
 
+int sdw_cdns_get_stream(struct sdw_cdns *cdns,
+			struct sdw_cdns_streams *stream,
+			u32 ch, u32 dir);
+int sdw_cdns_alloc_stream(struct sdw_cdns *cdns,
+			struct sdw_cdns_streams *stream,
+			struct sdw_cdns_port *port, u32 ch, u32 dir);
+void sdw_cdns_config_stream(struct sdw_cdns *cdns, struct sdw_cdns_port *port,
+			u32 ch, u32 dir, struct sdw_cdns_pdi *pdi);
+
+void sdw_cdns_shutdown(struct snd_pcm_substream *substream,
+				struct snd_soc_dai *dai);
+int sdw_cdns_pcm_set_stream(struct snd_soc_dai *dai,
+				void *stream, int direction);
+int sdw_cdns_pdm_set_stream(struct snd_soc_dai *dai,
+				void *stream, int direction);
+
+enum sdw_command_response
+cdns_reset_page_addr(struct sdw_bus *bus, unsigned int dev_num);
+
+enum sdw_command_response
+cdns_xfer_msg(struct sdw_bus *bus, struct sdw_msg *msg);
+
+enum sdw_command_response
+cdns_xfer_msg_defer(struct sdw_bus *bus,
+		struct sdw_msg *msg, struct sdw_defer *defer);
+
+enum sdw_command_response
+cdns_reset_page_addr(struct sdw_bus *bus, unsigned int dev_num);
+
+int cdns_bus_conf(struct sdw_bus *bus, struct sdw_bus_params *params);
 
+int cdns_set_sdw_stream(struct snd_soc_dai *dai,
+		void *stream, bool pcm, int direction);
 #endif /* __SDW_CADENCE_H */

drivers/soundwire/intel.h

@@ -10,6 +10,8 @@
  * @shim: Audio shim pointer
  * @alh: ALH (Audio Link Hub) pointer
  * @irq: Interrupt line
+ * @ops: Shim callback ops
+ * @arg: Shim callback ops argument
  *
  * This is set as pdata for each link instance.
  */
@@ -18,6 +20,8 @@ struct sdw_intel_link_res {
 	void __iomem *shim;
 	void __iomem *alh;
 	int irq;
+	const struct sdw_intel_ops *ops;
+	void *arg;
 };
 
 #endif /* __SDW_INTEL_LOCAL_H */

drivers/soundwire/intel_init.c

@@ -111,6 +111,9 @@ static struct sdw_intel_ctx
 		link->res.shim = res->mmio_base + SDW_SHIM_BASE;
 		link->res.alh = res->mmio_base + SDW_ALH_BASE;
 
+		link->res.ops = res->ops;
+		link->res.arg = res->arg;
+
 		memset(&pdevinfo, 0, sizeof(pdevinfo));
 
 		pdevinfo.parent = res->parent;

include/linux/soundwire/sdw_intel.h

@@ -4,18 +4,32 @@
 #ifndef __SDW_INTEL_H
 #define __SDW_INTEL_H
 
+/**
+ * struct sdw_intel_ops: Intel audio driver callback ops
+ *
+ * @config_stream: configure the stream with the hw_params
+ */
+struct sdw_intel_ops {
+	int (*config_stream)(void *arg, void *substream,
+			void *dai, void *hw_params, int stream_num);
+};
+
 /**
  * struct sdw_intel_res - Soundwire Intel resource structure
  * @mmio_base: mmio base of SoundWire registers
  * @irq: interrupt number
  * @handle: ACPI parent handle
  * @parent: parent device
+ * @ops: callback ops
+ * @arg: callback arg
  */
 struct sdw_intel_res {
 	void __iomem *mmio_base;
 	int irq;
 	acpi_handle handle;
 	struct device *parent;
+	const struct sdw_intel_ops *ops;
+	void *arg;
 };
 
 void *sdw_intel_init(acpi_handle *parent_handle, struct sdw_intel_res *res);

include/sound/soc-dai.h

@@ -170,6 +170,8 @@ struct snd_soc_dai_ops {
 		unsigned int rx_num, unsigned int *rx_slot);
 	int (*set_tristate)(struct snd_soc_dai *dai, int tristate);
 
+	int (*set_sdw_stream)(struct snd_soc_dai *dai,
+			void *stream, int direction);
 	/*
 	 * DAI digital mute - optional.
 	 * Called by soc-core to minimise any pops.
@@ -358,4 +360,25 @@ static inline void *snd_soc_dai_get_drvdata(struct snd_soc_dai *dai)
 	return dev_get_drvdata(dai->dev);
 }
 
+/**
+ * snd_soc_dai_set_sdw_stream() - Configures a DAI for SDW stream operation
+ * @dai: DAI
+ * @stream: STREAM
+ * @direction: Stream direction(Playback/Capture)
+ * SoundWire subsystem doesn't have a notion of direction and we reuse
+ * the ASoC stream direction to configure sink/source ports.
+ * Playback maps to source ports and Capture for sink ports.
+ *
+ * This should be invoked with NULL to clear the stream set previously.
+ * Returns 0 on success, a negative error code otherwise.
+ */
+static inline int snd_soc_dai_set_sdw_stream(struct snd_soc_dai *dai,
+				void *stream, int direction)
+{
+	if (dai->driver->ops->set_sdw_stream)
+		return dai->driver->ops->set_sdw_stream(dai, stream, direction);
+	else
+		return -ENOTSUPP;
+}
+
 #endif