ASoC: SOF: Introduce IPC SOF client support

A client in the SOF (Sound Open Firmware) context is a driver that needs
to communicate with the DSP via IPC messages. The SOF core is responsible
for serializing the IPC messages to the DSP from the different clients.

One example of an SOF client would be an IPC test client that floods the
DSP with test IPC messages to validate if the serialization works as
expected.

Multi-client support will also add the ability to split the existing audio
cards into multiple ones, so as to e.g. to deal with HDMI with a dedicated
client instead of adding HDMI to all cards.

This patch introduces descriptors for SOF client driver and SOF client
device along with APIs for registering and unregistering a SOF client
driver, sending IPCs from a client device and accessing the SOF core
debugfs root entry.

Along with this, add a couple of new members to struct snd_sof_dev that
will be used for maintaining the list of clients.

Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Co-developed-by: Fred Oh <fred.oh@linux.intel.com>
Signed-off-by: Fred Oh <fred.oh@linux.intel.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Link: https://lore.kernel.org/r/20220210150525.30756-6-peter.ujfalusi@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 69 insertions, 9 deletions

diff --git a/sound/soc/sof/sof-priv.h b/sound/soc/sof/sof-priv.h
index 27d2f3ca2f06..f641833f3ff9 100644
--- a/sound/soc/sof/sof-priv.h
+++ b/sound/soc/sof/sof-priv.h
@@ -292,6 +292,10 @@ struct snd_sof_dsp_ops {
 	void (*set_mach_params)(struct snd_soc_acpi_mach *mach,
 				struct snd_sof_dev *sdev); /* optional */
 
+	/* IPC client ops */
+	int (*register_ipc_clients)(struct snd_sof_dev *sdev); /* optional */
+	void (*unregister_ipc_clients)(struct snd_sof_dev *sdev); /* optional */
+
 	/* DAI ops */
 	struct snd_soc_dai_driver *drv;
 	int num_drv;
@@ -479,6 +483,30 @@ struct snd_sof_dev {
 	 */
 	int dsp_core_ref_count[SOF_MAX_DSP_NUM_CORES];
 
+	/*
+	 * Used to keep track of registered IPC client devices so that they can
+	 * be removed when the parent SOF module is removed.
+	 */
+	struct list_head ipc_client_list;
+
+	/* mutex to protect client list */
+	struct mutex ipc_client_mutex;
+
+	/*
+	 * Used for tracking the IPC client's RX registration for DSP initiated
+	 * message handling.
+	 */
+	struct list_head ipc_rx_handler_list;
+
+	/*
+	 * Used for tracking the IPC client's registration for DSP state change
+	 * notification
+	 */
+	struct list_head fw_state_handler_list;
+
+	/* to protect the ipc_rx_handler_list  and  dsp_state_handler_list list */
+	struct mutex client_event_handler_mutex;
+
 	void *private;			/* core does not touch this */
 };
 
@@ -582,15 +610,7 @@ extern const struct dsp_arch_ops sof_xtensa_arch_ops;
 /*
  * Firmware state tracking
  */
-static inline void sof_set_fw_state(struct snd_sof_dev *sdev,
-				    enum sof_fw_state new_state)
-{
-	if (sdev->fw_state == new_state)
-		return;
-
-	dev_dbg(sdev->dev, "fw_state change: %d -> %d\n", sdev->fw_state, new_state);
-	sdev->fw_state = new_state;
-}
+void sof_set_fw_state(struct snd_sof_dev *sdev, enum sof_fw_state new_state);
 
 /*
  * Utilities
@@ -623,4 +643,44 @@ int sof_stream_pcm_close(struct snd_sof_dev *sdev,
 			 struct snd_pcm_substream *substream);
 
 int sof_machine_check(struct snd_sof_dev *sdev);
+
+/* SOF client support */
+#if IS_ENABLED(CONFIG_SND_SOC_SOF_CLIENT)
+int sof_client_dev_register(struct snd_sof_dev *sdev, const char *name, u32 id,
+			    const void *data, size_t size);
+void sof_client_dev_unregister(struct snd_sof_dev *sdev, const char *name, u32 id);
+int sof_register_clients(struct snd_sof_dev *sdev);
+void sof_unregister_clients(struct snd_sof_dev *sdev);
+void sof_client_ipc_rx_dispatcher(struct snd_sof_dev *sdev, void *msg_buf);
+void sof_client_fw_state_dispatcher(struct snd_sof_dev *sdev);
+#else /* CONFIG_SND_SOC_SOF_CLIENT */
+static inline int sof_client_dev_register(struct snd_sof_dev *sdev, const char *name,
+					  u32 id, const void *data, size_t size)
+{
+	return 0;
+}
+
+static inline void sof_client_dev_unregister(struct snd_sof_dev *sdev,
+					     const char *name, u32 id)
+{
+}
+
+static inline int sof_register_clients(struct snd_sof_dev *sdev)
+{
+	return 0;
+}
+
+static inline  void sof_unregister_clients(struct snd_sof_dev *sdev)
+{
+}
+
+static inline void sof_client_ipc_rx_dispatcher(struct snd_sof_dev *sdev, void *msg_buf)
+{
+}
+
+static inline void sof_client_fw_state_dispatcher(struct snd_sof_dev *sdev)
+{
+}
+#endif /* CONFIG_SND_SOC_SOF_CLIENT */
+
 #endif