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, 340 insertions, 0 deletions

diff --git a/sound/soc/sof/sof-client.c b/sound/soc/sof/sof-client.c
new file mode 100644
index 000000000000..6f747d051b59
--- /dev/null
+++ b/sound/soc/sof/sof-client.c
@@ -0,0 +1,340 @@
+// SPDX-License-Identifier: GPL-2.0-only
+//
+// Copyright(c) 2022 Intel Corporation. All rights reserved.
+//
+// Authors: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
+//	    Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
+//
+
+#include <linux/debugfs.h>
+#include <linux/errno.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include "ops.h"
+#include "sof-client.h"
+#include "sof-priv.h"
+
+/**
+ * struct sof_ipc_event_entry - IPC client event description
+ * @ipc_msg_type:	IPC msg type of the event the client is interested
+ * @cdev:		sof_client_dev of the requesting client
+ * @callback:		Callback function of the client
+ * @list:		item in SOF core client event list
+ */
+struct sof_ipc_event_entry {
+	u32 ipc_msg_type;
+	struct sof_client_dev *cdev;
+	sof_client_event_callback callback;
+	struct list_head list;
+};
+
+/**
+ * struct sof_state_event_entry - DSP panic event subscription entry
+ * @cdev:		sof_client_dev of the requesting client
+ * @callback:		Callback function of the client
+ * @list:		item in SOF core client event list
+ */
+struct sof_state_event_entry {
+	struct sof_client_dev *cdev;
+	sof_client_fw_state_callback callback;
+	struct list_head list;
+};
+
+static void sof_client_auxdev_release(struct device *dev)
+{
+	struct auxiliary_device *auxdev = to_auxiliary_dev(dev);
+	struct sof_client_dev *cdev = auxiliary_dev_to_sof_client_dev(auxdev);
+
+	kfree(cdev->auxdev.dev.platform_data);
+	kfree(cdev);
+}
+
+static int sof_client_dev_add_data(struct sof_client_dev *cdev, const void *data,
+				   size_t size)
+{
+	void *d = NULL;
+
+	if (data) {
+		d = kmemdup(data, size, GFP_KERNEL);
+		if (!d)
+			return -ENOMEM;
+	}
+
+	cdev->auxdev.dev.platform_data = d;
+	return 0;
+}
+
+int sof_register_clients(struct snd_sof_dev *sdev)
+{
+	if (sof_ops(sdev) && sof_ops(sdev)->register_ipc_clients)
+		return sof_ops(sdev)->register_ipc_clients(sdev);
+
+	return 0;
+}
+
+void sof_unregister_clients(struct snd_sof_dev *sdev)
+{
+	if (sof_ops(sdev) && sof_ops(sdev)->unregister_ipc_clients)
+		sof_ops(sdev)->unregister_ipc_clients(sdev);
+}
+
+int sof_client_dev_register(struct snd_sof_dev *sdev, const char *name, u32 id,
+			    const void *data, size_t size)
+{
+	struct auxiliary_device *auxdev;
+	struct sof_client_dev *cdev;
+	int ret;
+
+	cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
+	if (!cdev)
+		return -ENOMEM;
+
+	cdev->sdev = sdev;
+	auxdev = &cdev->auxdev;
+	auxdev->name = name;
+	auxdev->dev.parent = sdev->dev;
+	auxdev->dev.release = sof_client_auxdev_release;
+	auxdev->id = id;
+
+	ret = sof_client_dev_add_data(cdev, data, size);
+	if (ret < 0)
+		goto err_dev_add_data;
+
+	ret = auxiliary_device_init(auxdev);
+	if (ret < 0) {
+		dev_err(sdev->dev, "failed to initialize client dev %s.%d\n", name, id);
+		goto err_dev_init;
+	}
+
+	ret = auxiliary_device_add(&cdev->auxdev);
+	if (ret < 0) {
+		dev_err(sdev->dev, "failed to add client dev %s.%d\n", name, id);
+		/*
+		 * sof_client_auxdev_release() will be invoked to free up memory
+		 * allocations through put_device()
+		 */
+		auxiliary_device_uninit(&cdev->auxdev);
+		return ret;
+	}
+
+	/* add to list of SOF client devices */
+	mutex_lock(&sdev->ipc_client_mutex);
+	list_add(&cdev->list, &sdev->ipc_client_list);
+	mutex_unlock(&sdev->ipc_client_mutex);
+
+	return 0;
+
+err_dev_init:
+	kfree(cdev->auxdev.dev.platform_data);
+
+err_dev_add_data:
+	kfree(cdev);
+
+	return ret;
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_dev_register, SND_SOC_SOF_CLIENT);
+
+void sof_client_dev_unregister(struct snd_sof_dev *sdev, const char *name, u32 id)
+{
+	struct sof_client_dev *cdev;
+
+	mutex_lock(&sdev->ipc_client_mutex);
+
+	/*
+	 * sof_client_auxdev_release() will be invoked to free up memory
+	 * allocations through put_device()
+	 */
+	list_for_each_entry(cdev, &sdev->ipc_client_list, list) {
+		if (!strcmp(cdev->auxdev.name, name) && cdev->auxdev.id == id) {
+			list_del(&cdev->list);
+			auxiliary_device_delete(&cdev->auxdev);
+			auxiliary_device_uninit(&cdev->auxdev);
+			break;
+		}
+	}
+
+	mutex_unlock(&sdev->ipc_client_mutex);
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_dev_unregister, SND_SOC_SOF_CLIENT);
+
+int sof_client_ipc_tx_message(struct sof_client_dev *cdev, void *ipc_msg,
+			      void *reply_data, size_t reply_bytes)
+{
+	struct sof_ipc_cmd_hdr *hdr = ipc_msg;
+
+	return sof_ipc_tx_message(cdev->sdev->ipc, hdr->cmd, ipc_msg, hdr->size,
+				  reply_data, reply_bytes);
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_ipc_tx_message, SND_SOC_SOF_CLIENT);
+
+struct dentry *sof_client_get_debugfs_root(struct sof_client_dev *cdev)
+{
+	return cdev->sdev->debugfs_root;
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_get_debugfs_root, SND_SOC_SOF_CLIENT);
+
+/* DMA buffer allocation in client drivers must use the core SOF device */
+struct device *sof_client_get_dma_dev(struct sof_client_dev *cdev)
+{
+	return cdev->sdev->dev;
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_get_dma_dev, SND_SOC_SOF_CLIENT);
+
+const struct sof_ipc_fw_version *sof_client_get_fw_version(struct sof_client_dev *cdev)
+{
+	struct snd_sof_dev *sdev = sof_client_dev_to_sof_dev(cdev);
+
+	return &sdev->fw_ready.version;
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_get_fw_version, SND_SOC_SOF_CLIENT);
+
+/* module refcount management of SOF core */
+int sof_client_core_module_get(struct sof_client_dev *cdev)
+{
+	struct snd_sof_dev *sdev = sof_client_dev_to_sof_dev(cdev);
+
+	if (!try_module_get(sdev->dev->driver->owner))
+		return -ENODEV;
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_core_module_get, SND_SOC_SOF_CLIENT);
+
+void sof_client_core_module_put(struct sof_client_dev *cdev)
+{
+	struct snd_sof_dev *sdev = sof_client_dev_to_sof_dev(cdev);
+
+	module_put(sdev->dev->driver->owner);
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_core_module_put, SND_SOC_SOF_CLIENT);
+
+/* IPC event handling */
+void sof_client_ipc_rx_dispatcher(struct snd_sof_dev *sdev, void *msg_buf)
+{
+	struct sof_ipc_cmd_hdr *hdr = msg_buf;
+	u32 msg_type = hdr->cmd & SOF_GLB_TYPE_MASK;
+	struct sof_ipc_event_entry *event;
+
+	mutex_lock(&sdev->client_event_handler_mutex);
+
+	list_for_each_entry(event, &sdev->ipc_rx_handler_list, list) {
+		if (event->ipc_msg_type == msg_type)
+			event->callback(event->cdev, msg_buf);
+	}
+
+	mutex_unlock(&sdev->client_event_handler_mutex);
+}
+
+int sof_client_register_ipc_rx_handler(struct sof_client_dev *cdev,
+				       u32 ipc_msg_type,
+				       sof_client_event_callback callback)
+{
+	struct snd_sof_dev *sdev = sof_client_dev_to_sof_dev(cdev);
+	struct sof_ipc_event_entry *event;
+
+	if (!callback || !(ipc_msg_type & SOF_GLB_TYPE_MASK))
+		return -EINVAL;
+
+	event = kmalloc(sizeof(*event), GFP_KERNEL);
+	if (!event)
+		return -ENOMEM;
+
+	event->ipc_msg_type = ipc_msg_type;
+	event->cdev = cdev;
+	event->callback = callback;
+
+	/* add to list of SOF client devices */
+	mutex_lock(&sdev->client_event_handler_mutex);
+	list_add(&event->list, &sdev->ipc_rx_handler_list);
+	mutex_unlock(&sdev->client_event_handler_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_register_ipc_rx_handler, SND_SOC_SOF_CLIENT);
+
+void sof_client_unregister_ipc_rx_handler(struct sof_client_dev *cdev,
+					  u32 ipc_msg_type)
+{
+	struct snd_sof_dev *sdev = sof_client_dev_to_sof_dev(cdev);
+	struct sof_ipc_event_entry *event;
+
+	mutex_lock(&sdev->client_event_handler_mutex);
+
+	list_for_each_entry(event, &sdev->ipc_rx_handler_list, list) {
+		if (event->cdev == cdev && event->ipc_msg_type == ipc_msg_type) {
+			list_del(&event->list);
+			kfree(event);
+			break;
+		}
+	}
+
+	mutex_unlock(&sdev->client_event_handler_mutex);
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_unregister_ipc_rx_handler, SND_SOC_SOF_CLIENT);
+
+/*DSP state notification and query */
+void sof_client_fw_state_dispatcher(struct snd_sof_dev *sdev)
+{
+	struct sof_state_event_entry *event;
+
+	mutex_lock(&sdev->client_event_handler_mutex);
+
+	list_for_each_entry(event, &sdev->fw_state_handler_list, list)
+		event->callback(event->cdev, sdev->fw_state);
+
+	mutex_unlock(&sdev->client_event_handler_mutex);
+}
+
+int sof_client_register_fw_state_handler(struct sof_client_dev *cdev,
+					 sof_client_fw_state_callback callback)
+{
+	struct snd_sof_dev *sdev = sof_client_dev_to_sof_dev(cdev);
+	struct sof_state_event_entry *event;
+
+	if (!callback)
+		return -EINVAL;
+
+	event = kmalloc(sizeof(*event), GFP_KERNEL);
+	if (!event)
+		return -ENOMEM;
+
+	event->cdev = cdev;
+	event->callback = callback;
+
+	/* add to list of SOF client devices */
+	mutex_lock(&sdev->client_event_handler_mutex);
+	list_add(&event->list, &sdev->fw_state_handler_list);
+	mutex_unlock(&sdev->client_event_handler_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_register_fw_state_handler, SND_SOC_SOF_CLIENT);
+
+void sof_client_unregister_fw_state_handler(struct sof_client_dev *cdev)
+{
+	struct snd_sof_dev *sdev = sof_client_dev_to_sof_dev(cdev);
+	struct sof_state_event_entry *event;
+
+	mutex_lock(&sdev->client_event_handler_mutex);
+
+	list_for_each_entry(event, &sdev->fw_state_handler_list, list) {
+		if (event->cdev == cdev) {
+			list_del(&event->list);
+			kfree(event);
+			break;
+		}
+	}
+
+	mutex_unlock(&sdev->client_event_handler_mutex);
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_unregister_fw_state_handler, SND_SOC_SOF_CLIENT);
+
+enum sof_fw_state sof_client_get_fw_state(struct sof_client_dev *cdev)
+{
+	struct snd_sof_dev *sdev = sof_client_dev_to_sof_dev(cdev);
+
+	return sdev->fw_state;
+}
+EXPORT_SYMBOL_NS_GPL(sof_client_get_fw_state, SND_SOC_SOF_CLIENT);