Resguardo inicial

linux-7.2.3/drivers/most/Kconfig

@@ -0,0 +1,45 @@
+# SPDX-License-Identifier: GPL-2.0
+menuconfig MOST
+	tristate "MOST (Media Oriented Systems Transport) support"
+	depends on HAS_DMA && CONFIGFS_FS
+	default n
+	help
+	  Say Y here if you want to enable MOST support.
+	  This driver needs at least one additional component to enable the
+	  desired access from userspace (e.g. character devices) and one that
+	  matches the network controller's hardware interface (e.g. USB).
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called most_core.
+
+	  If in doubt, say N here.
+
+if MOST
+config MOST_USB_HDM
+	tristate "USB"
+	depends on USB
+	help
+	  Say Y here if you want to connect via USB to network transceiver.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called most_usb.
+
+config MOST_CDEV
+	tristate "Cdev"
+
+	help
+	  Say Y here if you want to commumicate via character devices.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called most_cdev.
+
+config MOST_SND
+	tristate "Sound"
+	depends on SND
+	select SND_PCM
+	help
+	  Say Y here if you want to commumicate via ALSA/sound devices.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called most_sound.
+endif

linux-7.2.3/drivers/most/Makefile

@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_MOST) += most_core.o
+most_core-y :=	core.o \
+		configfs.o
+
+obj-$(CONFIG_MOST_USB_HDM) += most_usb.o
+obj-$(CONFIG_MOST_CDEV) += most_cdev.o
+obj-$(CONFIG_MOST_SND) += most_snd.o

linux-7.2.3/drivers/most/configfs.c

@@ -0,0 +1,724 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * configfs.c - Implementation of configfs interface to the driver stack
+ *
+ * Copyright (C) 2013-2015 Microchip Technology Germany II GmbH & Co. KG
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/configfs.h>
+#include <linux/most.h>
+
+#define MAX_STRING_SIZE 80
+
+struct mdev_link {
+	struct config_item item;
+	struct list_head list;
+	bool create_link;
+	bool destroy_link;
+	u16 num_buffers;
+	u16 buffer_size;
+	u16 subbuffer_size;
+	u16 packets_per_xact;
+	u16 dbr_size;
+	char datatype[MAX_STRING_SIZE];
+	char direction[MAX_STRING_SIZE];
+	char name[MAX_STRING_SIZE];
+	char device[MAX_STRING_SIZE];
+	char channel[MAX_STRING_SIZE];
+	char comp[MAX_STRING_SIZE];
+	char comp_params[MAX_STRING_SIZE];
+};
+
+static struct list_head mdev_link_list;
+
+static int set_cfg_buffer_size(struct mdev_link *link)
+{
+	return most_set_cfg_buffer_size(link->device, link->channel,
+					link->buffer_size);
+}
+
+static int set_cfg_subbuffer_size(struct mdev_link *link)
+{
+	return most_set_cfg_subbuffer_size(link->device, link->channel,
+					   link->subbuffer_size);
+}
+
+static int set_cfg_dbr_size(struct mdev_link *link)
+{
+	return most_set_cfg_dbr_size(link->device, link->channel,
+				     link->dbr_size);
+}
+
+static int set_cfg_num_buffers(struct mdev_link *link)
+{
+	return most_set_cfg_num_buffers(link->device, link->channel,
+					link->num_buffers);
+}
+
+static int set_cfg_packets_xact(struct mdev_link *link)
+{
+	return most_set_cfg_packets_xact(link->device, link->channel,
+					 link->packets_per_xact);
+}
+
+static int set_cfg_direction(struct mdev_link *link)
+{
+	return most_set_cfg_direction(link->device, link->channel,
+				      link->direction);
+}
+
+static int set_cfg_datatype(struct mdev_link *link)
+{
+	return most_set_cfg_datatype(link->device, link->channel,
+				     link->datatype);
+}
+
+static int (*set_config_val[])(struct mdev_link *link) = {
+	set_cfg_buffer_size,
+	set_cfg_subbuffer_size,
+	set_cfg_dbr_size,
+	set_cfg_num_buffers,
+	set_cfg_packets_xact,
+	set_cfg_direction,
+	set_cfg_datatype,
+};
+
+static struct mdev_link *to_mdev_link(struct config_item *item)
+{
+	return container_of(item, struct mdev_link, item);
+}
+
+static int set_config_and_add_link(struct mdev_link *mdev_link)
+{
+	int i;
+	int ret;
+
+	for (i = 0; i < ARRAY_SIZE(set_config_val); i++) {
+		ret = set_config_val[i](mdev_link);
+		if (ret < 0 && ret != -ENODEV) {
+			pr_err("Config failed\n");
+			return ret;
+		}
+	}
+
+	return most_add_link(mdev_link->device, mdev_link->channel,
+			     mdev_link->comp, mdev_link->name,
+			     mdev_link->comp_params);
+}
+
+static ssize_t mdev_link_create_link_store(struct config_item *item,
+					   const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+	bool tmp;
+	int ret;
+
+	ret = kstrtobool(page, &tmp);
+	if (ret)
+		return ret;
+	if (!tmp)
+		return count;
+	ret = set_config_and_add_link(mdev_link);
+	if (ret && ret != -ENODEV)
+		return ret;
+	list_add_tail(&mdev_link->list, &mdev_link_list);
+	mdev_link->create_link = tmp;
+	mdev_link->destroy_link = false;
+
+	return count;
+}
+
+static ssize_t mdev_link_destroy_link_store(struct config_item *item,
+					    const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+	bool tmp;
+	int ret;
+
+	ret = kstrtobool(page, &tmp);
+	if (ret)
+		return ret;
+	if (!tmp)
+		return count;
+
+	ret = most_remove_link(mdev_link->device, mdev_link->channel,
+			       mdev_link->comp);
+	if (ret)
+		return ret;
+	if (!list_empty(&mdev_link_list))
+		list_del(&mdev_link->list);
+
+	mdev_link->destroy_link = tmp;
+
+	return count;
+}
+
+static ssize_t mdev_link_direction_show(struct config_item *item, char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%s\n", to_mdev_link(item)->direction);
+}
+
+static ssize_t mdev_link_direction_store(struct config_item *item,
+					 const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+
+	if (!sysfs_streq(page, "dir_rx") && !sysfs_streq(page, "rx") &&
+	    !sysfs_streq(page, "dir_tx") && !sysfs_streq(page, "tx"))
+		return -EINVAL;
+	strcpy(mdev_link->direction, page);
+	strim(mdev_link->direction);
+	return count;
+}
+
+static ssize_t mdev_link_datatype_show(struct config_item *item, char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%s\n", to_mdev_link(item)->datatype);
+}
+
+static ssize_t mdev_link_datatype_store(struct config_item *item,
+					const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+
+	if (!sysfs_streq(page, "control") && !sysfs_streq(page, "async") &&
+	    !sysfs_streq(page, "sync") && !sysfs_streq(page, "isoc") &&
+	    !sysfs_streq(page, "isoc_avp"))
+		return -EINVAL;
+	strcpy(mdev_link->datatype, page);
+	strim(mdev_link->datatype);
+	return count;
+}
+
+static ssize_t mdev_link_device_show(struct config_item *item, char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%s\n", to_mdev_link(item)->device);
+}
+
+static ssize_t mdev_link_device_store(struct config_item *item,
+				      const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+
+	strscpy(mdev_link->device, page, sizeof(mdev_link->device));
+	strim(mdev_link->device);
+	return count;
+}
+
+static ssize_t mdev_link_channel_show(struct config_item *item, char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%s\n", to_mdev_link(item)->channel);
+}
+
+static ssize_t mdev_link_channel_store(struct config_item *item,
+				       const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+
+	strscpy(mdev_link->channel, page, sizeof(mdev_link->channel));
+	strim(mdev_link->channel);
+	return count;
+}
+
+static ssize_t mdev_link_comp_show(struct config_item *item, char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%s\n", to_mdev_link(item)->comp);
+}
+
+static ssize_t mdev_link_comp_store(struct config_item *item,
+				    const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+
+	strscpy(mdev_link->comp, page, sizeof(mdev_link->comp));
+	strim(mdev_link->comp);
+	return count;
+}
+
+static ssize_t mdev_link_comp_params_show(struct config_item *item, char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%s\n",
+			to_mdev_link(item)->comp_params);
+}
+
+static ssize_t mdev_link_comp_params_store(struct config_item *item,
+					   const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+
+	strscpy(mdev_link->comp_params, page, sizeof(mdev_link->comp_params));
+	strim(mdev_link->comp_params);
+	return count;
+}
+
+static ssize_t mdev_link_num_buffers_show(struct config_item *item, char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%d\n",
+			to_mdev_link(item)->num_buffers);
+}
+
+static ssize_t mdev_link_num_buffers_store(struct config_item *item,
+					   const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+	int ret;
+
+	ret = kstrtou16(page, 0, &mdev_link->num_buffers);
+	if (ret)
+		return ret;
+	return count;
+}
+
+static ssize_t mdev_link_buffer_size_show(struct config_item *item, char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%d\n",
+			to_mdev_link(item)->buffer_size);
+}
+
+static ssize_t mdev_link_buffer_size_store(struct config_item *item,
+					   const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+	int ret;
+
+	ret = kstrtou16(page, 0, &mdev_link->buffer_size);
+	if (ret)
+		return ret;
+	return count;
+}
+
+static ssize_t mdev_link_subbuffer_size_show(struct config_item *item,
+					     char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%d\n",
+			to_mdev_link(item)->subbuffer_size);
+}
+
+static ssize_t mdev_link_subbuffer_size_store(struct config_item *item,
+					      const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+	int ret;
+
+	ret = kstrtou16(page, 0, &mdev_link->subbuffer_size);
+	if (ret)
+		return ret;
+	return count;
+}
+
+static ssize_t mdev_link_packets_per_xact_show(struct config_item *item,
+					       char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%d\n",
+			to_mdev_link(item)->packets_per_xact);
+}
+
+static ssize_t mdev_link_packets_per_xact_store(struct config_item *item,
+						const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+	int ret;
+
+	ret = kstrtou16(page, 0, &mdev_link->packets_per_xact);
+	if (ret)
+		return ret;
+	return count;
+}
+
+static ssize_t mdev_link_dbr_size_show(struct config_item *item, char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%d\n", to_mdev_link(item)->dbr_size);
+}
+
+static ssize_t mdev_link_dbr_size_store(struct config_item *item,
+					const char *page, size_t count)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+	int ret;
+
+	ret = kstrtou16(page, 0, &mdev_link->dbr_size);
+	if (ret)
+		return ret;
+	return count;
+}
+
+CONFIGFS_ATTR_WO(mdev_link_, create_link);
+CONFIGFS_ATTR_WO(mdev_link_, destroy_link);
+CONFIGFS_ATTR(mdev_link_, device);
+CONFIGFS_ATTR(mdev_link_, channel);
+CONFIGFS_ATTR(mdev_link_, comp);
+CONFIGFS_ATTR(mdev_link_, comp_params);
+CONFIGFS_ATTR(mdev_link_, num_buffers);
+CONFIGFS_ATTR(mdev_link_, buffer_size);
+CONFIGFS_ATTR(mdev_link_, subbuffer_size);
+CONFIGFS_ATTR(mdev_link_, packets_per_xact);
+CONFIGFS_ATTR(mdev_link_, datatype);
+CONFIGFS_ATTR(mdev_link_, direction);
+CONFIGFS_ATTR(mdev_link_, dbr_size);
+
+static struct configfs_attribute *mdev_link_attrs[] = {
+	&mdev_link_attr_create_link,
+	&mdev_link_attr_destroy_link,
+	&mdev_link_attr_device,
+	&mdev_link_attr_channel,
+	&mdev_link_attr_comp,
+	&mdev_link_attr_comp_params,
+	&mdev_link_attr_num_buffers,
+	&mdev_link_attr_buffer_size,
+	&mdev_link_attr_subbuffer_size,
+	&mdev_link_attr_packets_per_xact,
+	&mdev_link_attr_datatype,
+	&mdev_link_attr_direction,
+	&mdev_link_attr_dbr_size,
+	NULL,
+};
+
+static void mdev_link_release(struct config_item *item)
+{
+	struct mdev_link *mdev_link = to_mdev_link(item);
+	int ret;
+
+	if (mdev_link->destroy_link)
+		goto free_item;
+
+	ret = most_remove_link(mdev_link->device, mdev_link->channel,
+			       mdev_link->comp);
+	if (ret) {
+		pr_err("Removing link failed.\n");
+		goto free_item;
+	}
+
+	if (!list_empty(&mdev_link_list))
+		list_del(&mdev_link->list);
+
+free_item:
+	kfree(to_mdev_link(item));
+}
+
+static struct configfs_item_operations mdev_link_item_ops = {
+	.release		= mdev_link_release,
+};
+
+static const struct config_item_type mdev_link_type = {
+	.ct_item_ops	= &mdev_link_item_ops,
+	.ct_attrs	= mdev_link_attrs,
+	.ct_owner	= THIS_MODULE,
+};
+
+struct most_common {
+	struct config_group group;
+	struct module *mod;
+	struct configfs_subsystem subsys;
+};
+
+static struct most_common *to_most_common(struct configfs_subsystem *subsys)
+{
+	return container_of(subsys, struct most_common, subsys);
+}
+
+static struct config_item *most_common_make_item(struct config_group *group,
+						 const char *name)
+{
+	struct mdev_link *mdev_link;
+	struct most_common *mc = to_most_common(group->cg_subsys);
+
+	mdev_link = kzalloc_obj(*mdev_link);
+	if (!mdev_link)
+		return ERR_PTR(-ENOMEM);
+
+	if (!try_module_get(mc->mod)) {
+		kfree(mdev_link);
+		return ERR_PTR(-ENOLCK);
+	}
+	config_item_init_type_name(&mdev_link->item, name,
+				   &mdev_link_type);
+
+	if (!strcmp(group->cg_item.ci_namebuf, "most_cdev"))
+		strcpy(mdev_link->comp, "cdev");
+	else if (!strcmp(group->cg_item.ci_namebuf, "most_net"))
+		strcpy(mdev_link->comp, "net");
+	else if (!strcmp(group->cg_item.ci_namebuf, "most_video"))
+		strcpy(mdev_link->comp, "video");
+	strcpy(mdev_link->name, name);
+	return &mdev_link->item;
+}
+
+static void most_common_release(struct config_item *item)
+{
+	struct config_group *group = to_config_group(item);
+
+	kfree(to_most_common(group->cg_subsys));
+}
+
+static struct configfs_item_operations most_common_item_ops = {
+	.release	= most_common_release,
+};
+
+static void most_common_disconnect(struct config_group *group,
+				   struct config_item *item)
+{
+	struct most_common *mc = to_most_common(group->cg_subsys);
+
+	module_put(mc->mod);
+}
+
+static struct configfs_group_operations most_common_group_ops = {
+	.make_item	= most_common_make_item,
+	.disconnect_notify = most_common_disconnect,
+};
+
+static const struct config_item_type most_common_type = {
+	.ct_item_ops	= &most_common_item_ops,
+	.ct_group_ops	= &most_common_group_ops,
+	.ct_owner	= THIS_MODULE,
+};
+
+static struct most_common most_cdev = {
+	.subsys = {
+		.su_group = {
+			.cg_item = {
+				.ci_namebuf = "most_cdev",
+				.ci_type = &most_common_type,
+			},
+		},
+	},
+};
+
+static struct most_common most_net = {
+	.subsys = {
+		.su_group = {
+			.cg_item = {
+				.ci_namebuf = "most_net",
+				.ci_type = &most_common_type,
+			},
+		},
+	},
+};
+
+static struct most_common most_video = {
+	.subsys = {
+		.su_group = {
+			.cg_item = {
+				.ci_namebuf = "most_video",
+				.ci_type = &most_common_type,
+			},
+		},
+	},
+};
+
+struct most_snd_grp {
+	struct config_group group;
+	bool create_card;
+	struct list_head list;
+};
+
+static struct most_snd_grp *to_most_snd_grp(struct config_item *item)
+{
+	return container_of(to_config_group(item), struct most_snd_grp, group);
+}
+
+static struct config_item *most_snd_grp_make_item(struct config_group *group,
+						  const char *name)
+{
+	struct mdev_link *mdev_link;
+
+	mdev_link = kzalloc_obj(*mdev_link);
+	if (!mdev_link)
+		return ERR_PTR(-ENOMEM);
+
+	config_item_init_type_name(&mdev_link->item, name, &mdev_link_type);
+	mdev_link->create_link = false;
+	strcpy(mdev_link->name, name);
+	strcpy(mdev_link->comp, "sound");
+	return &mdev_link->item;
+}
+
+static ssize_t most_snd_grp_create_card_store(struct config_item *item,
+					      const char *page, size_t count)
+{
+	struct most_snd_grp *snd_grp = to_most_snd_grp(item);
+	int ret;
+	bool tmp;
+
+	ret = kstrtobool(page, &tmp);
+	if (ret)
+		return ret;
+	if (tmp) {
+		ret = most_cfg_complete("sound");
+		if (ret)
+			return ret;
+	}
+	snd_grp->create_card = tmp;
+	return count;
+}
+
+CONFIGFS_ATTR_WO(most_snd_grp_, create_card);
+
+static struct configfs_attribute *most_snd_grp_attrs[] = {
+	&most_snd_grp_attr_create_card,
+	NULL,
+};
+
+static void most_snd_grp_release(struct config_item *item)
+{
+	struct most_snd_grp *group = to_most_snd_grp(item);
+
+	list_del(&group->list);
+	kfree(group);
+}
+
+static struct configfs_item_operations most_snd_grp_item_ops = {
+	.release	= most_snd_grp_release,
+};
+
+static struct configfs_group_operations most_snd_grp_group_ops = {
+	.make_item	= most_snd_grp_make_item,
+};
+
+static const struct config_item_type most_snd_grp_type = {
+	.ct_item_ops	= &most_snd_grp_item_ops,
+	.ct_group_ops	= &most_snd_grp_group_ops,
+	.ct_attrs	= most_snd_grp_attrs,
+	.ct_owner	= THIS_MODULE,
+};
+
+struct most_sound {
+	struct configfs_subsystem subsys;
+	struct list_head soundcard_list;
+	struct module *mod;
+};
+
+static struct config_group *most_sound_make_group(struct config_group *group,
+						  const char *name)
+{
+	struct most_snd_grp *most;
+	struct most_sound *ms = container_of(group->cg_subsys,
+					     struct most_sound, subsys);
+
+	list_for_each_entry(most, &ms->soundcard_list, list) {
+		if (!most->create_card) {
+			pr_info("adapter configuration still in progress.\n");
+			return ERR_PTR(-EPROTO);
+		}
+	}
+	if (!try_module_get(ms->mod))
+		return ERR_PTR(-ENOLCK);
+	most = kzalloc_obj(*most);
+	if (!most) {
+		module_put(ms->mod);
+		return ERR_PTR(-ENOMEM);
+	}
+	config_group_init_type_name(&most->group, name, &most_snd_grp_type);
+	list_add_tail(&most->list, &ms->soundcard_list);
+	return &most->group;
+}
+
+static void most_sound_disconnect(struct config_group *group,
+				  struct config_item *item)
+{
+	struct most_sound *ms = container_of(group->cg_subsys,
+					     struct most_sound, subsys);
+	module_put(ms->mod);
+}
+
+static struct configfs_group_operations most_sound_group_ops = {
+	.make_group	= most_sound_make_group,
+	.disconnect_notify = most_sound_disconnect,
+};
+
+static const struct config_item_type most_sound_type = {
+	.ct_group_ops	= &most_sound_group_ops,
+	.ct_owner	= THIS_MODULE,
+};
+
+static struct most_sound most_sound_subsys = {
+	.subsys = {
+		.su_group = {
+			.cg_item = {
+				.ci_namebuf = "most_sound",
+				.ci_type = &most_sound_type,
+			},
+		},
+	},
+};
+
+int most_register_configfs_subsys(struct most_component *c)
+{
+	int ret;
+
+	if (!strcmp(c->name, "cdev")) {
+		most_cdev.mod = c->mod;
+		ret = configfs_register_subsystem(&most_cdev.subsys);
+	} else if (!strcmp(c->name, "net")) {
+		most_net.mod = c->mod;
+		ret = configfs_register_subsystem(&most_net.subsys);
+	} else if (!strcmp(c->name, "video")) {
+		most_video.mod = c->mod;
+		ret = configfs_register_subsystem(&most_video.subsys);
+	} else if (!strcmp(c->name, "sound")) {
+		most_sound_subsys.mod = c->mod;
+		ret = configfs_register_subsystem(&most_sound_subsys.subsys);
+	} else {
+		return -ENODEV;
+	}
+
+	if (ret) {
+		pr_err("Error %d while registering subsystem %s\n",
+		       ret, c->name);
+	}
+	return ret;
+}
+EXPORT_SYMBOL_GPL(most_register_configfs_subsys);
+
+void most_interface_register_notify(const char *mdev)
+{
+	bool register_snd_card = false;
+	struct mdev_link *mdev_link;
+
+	list_for_each_entry(mdev_link, &mdev_link_list, list) {
+		if (!strcmp(mdev_link->device, mdev)) {
+			set_config_and_add_link(mdev_link);
+			if (!strcmp(mdev_link->comp, "sound"))
+				register_snd_card = true;
+		}
+	}
+	if (register_snd_card)
+		most_cfg_complete("sound");
+}
+
+void most_deregister_configfs_subsys(struct most_component *c)
+{
+	if (!strcmp(c->name, "cdev"))
+		configfs_unregister_subsystem(&most_cdev.subsys);
+	else if (!strcmp(c->name, "net"))
+		configfs_unregister_subsystem(&most_net.subsys);
+	else if (!strcmp(c->name, "video"))
+		configfs_unregister_subsystem(&most_video.subsys);
+	else if (!strcmp(c->name, "sound"))
+		configfs_unregister_subsystem(&most_sound_subsys.subsys);
+}
+EXPORT_SYMBOL_GPL(most_deregister_configfs_subsys);
+
+int __init configfs_init(void)
+{
+	config_group_init(&most_cdev.subsys.su_group);
+	mutex_init(&most_cdev.subsys.su_mutex);
+
+	config_group_init(&most_net.subsys.su_group);
+	mutex_init(&most_net.subsys.su_mutex);
+
+	config_group_init(&most_video.subsys.su_group);
+	mutex_init(&most_video.subsys.su_mutex);
+
+	config_group_init(&most_sound_subsys.subsys.su_group);
+	mutex_init(&most_sound_subsys.subsys.su_mutex);
+
+	INIT_LIST_HEAD(&most_sound_subsys.soundcard_list);
+	INIT_LIST_HEAD(&mdev_link_list);
+
+	return 0;
+}

linux-7.2.3/drivers/most/most_cdev.c

@@ -0,0 +1,546 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * cdev.c - Character device component for Mostcore
+ *
+ * Copyright (C) 2013-2015 Microchip Technology Germany II GmbH & Co. KG
+ */
+
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/cdev.h>
+#include <linux/poll.h>
+#include <linux/kfifo.h>
+#include <linux/uaccess.h>
+#include <linux/idr.h>
+#include <linux/most.h>
+
+#define CHRDEV_REGION_SIZE 50
+
+static const struct class most_cdev_class = {
+	.name		= "most_cdev"
+};
+
+static struct cdev_component {
+	dev_t devno;
+	struct ida minor_id;
+	unsigned int major;
+	struct most_component cc;
+} comp;
+
+struct comp_channel {
+	wait_queue_head_t wq;
+	spinlock_t unlink;	/* synchronization lock to unlink channels */
+	struct cdev cdev;
+	struct device *dev;
+	struct mutex io_mutex;
+	struct most_interface *iface;
+	struct most_channel_config *cfg;
+	unsigned int channel_id;
+	dev_t devno;
+	size_t mbo_offs;
+	DECLARE_KFIFO_PTR(fifo, typeof(struct mbo *));
+	int access_ref;
+	struct list_head list;
+};
+
+#define to_channel(d) container_of(d, struct comp_channel, cdev)
+static LIST_HEAD(channel_list);
+static DEFINE_SPINLOCK(ch_list_lock);
+
+static inline bool ch_has_mbo(struct comp_channel *c)
+{
+	return channel_has_mbo(c->iface, c->channel_id, &comp.cc) > 0;
+}
+
+static inline struct mbo *ch_get_mbo(struct comp_channel *c, struct mbo **mbo)
+{
+	if (!kfifo_peek(&c->fifo, mbo)) {
+		*mbo = most_get_mbo(c->iface, c->channel_id, &comp.cc);
+		if (*mbo)
+			kfifo_in(&c->fifo, mbo, 1);
+	}
+	return *mbo;
+}
+
+static struct comp_channel *get_channel(struct most_interface *iface, int id)
+{
+	struct comp_channel *c, *tmp;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ch_list_lock, flags);
+	list_for_each_entry_safe(c, tmp, &channel_list, list) {
+		if ((c->iface == iface) && (c->channel_id == id)) {
+			spin_unlock_irqrestore(&ch_list_lock, flags);
+			return c;
+		}
+	}
+	spin_unlock_irqrestore(&ch_list_lock, flags);
+	return NULL;
+}
+
+static void stop_channel(struct comp_channel *c)
+{
+	struct mbo *mbo;
+
+	while (kfifo_out((struct kfifo *)&c->fifo, &mbo, 1))
+		most_put_mbo(mbo);
+	most_stop_channel(c->iface, c->channel_id, &comp.cc);
+}
+
+static void destroy_cdev(struct comp_channel *c)
+{
+	unsigned long flags;
+
+	device_destroy(&most_cdev_class, c->devno);
+	cdev_del(&c->cdev);
+	spin_lock_irqsave(&ch_list_lock, flags);
+	list_del(&c->list);
+	spin_unlock_irqrestore(&ch_list_lock, flags);
+}
+
+static void destroy_channel(struct comp_channel *c)
+{
+	ida_free(&comp.minor_id, MINOR(c->devno));
+	kfifo_free(&c->fifo);
+	kfree(c);
+}
+
+/**
+ * comp_open - implements the syscall to open the device
+ * @inode: inode pointer
+ * @filp: file pointer
+ *
+ * This stores the channel pointer in the private data field of
+ * the file structure and activates the channel within the core.
+ */
+static int comp_open(struct inode *inode, struct file *filp)
+{
+	struct comp_channel *c;
+	int ret;
+
+	c = to_channel(inode->i_cdev);
+	filp->private_data = c;
+
+	if (((c->cfg->direction == MOST_CH_RX) &&
+	     ((filp->f_flags & O_ACCMODE) != O_RDONLY)) ||
+	     ((c->cfg->direction == MOST_CH_TX) &&
+		((filp->f_flags & O_ACCMODE) != O_WRONLY))) {
+		return -EACCES;
+	}
+
+	mutex_lock(&c->io_mutex);
+	if (!c->dev) {
+		mutex_unlock(&c->io_mutex);
+		return -ENODEV;
+	}
+
+	if (c->access_ref) {
+		mutex_unlock(&c->io_mutex);
+		return -EBUSY;
+	}
+
+	c->mbo_offs = 0;
+	ret = most_start_channel(c->iface, c->channel_id, &comp.cc);
+	if (!ret)
+		c->access_ref = 1;
+	mutex_unlock(&c->io_mutex);
+	return ret;
+}
+
+/**
+ * comp_close - implements the syscall to close the device
+ * @inode: inode pointer
+ * @filp: file pointer
+ *
+ * This stops the channel within the core.
+ */
+static int comp_close(struct inode *inode, struct file *filp)
+{
+	struct comp_channel *c = to_channel(inode->i_cdev);
+
+	mutex_lock(&c->io_mutex);
+	spin_lock(&c->unlink);
+	c->access_ref = 0;
+	spin_unlock(&c->unlink);
+	if (c->dev) {
+		stop_channel(c);
+		mutex_unlock(&c->io_mutex);
+	} else {
+		mutex_unlock(&c->io_mutex);
+		destroy_channel(c);
+	}
+	return 0;
+}
+
+/**
+ * comp_write - implements the syscall to write to the device
+ * @filp: file pointer
+ * @buf: pointer to user buffer
+ * @count: number of bytes to write
+ * @offset: offset from where to start writing
+ */
+static ssize_t comp_write(struct file *filp, const char __user *buf,
+			  size_t count, loff_t *offset)
+{
+	int ret;
+	size_t to_copy, left;
+	struct mbo *mbo = NULL;
+	struct comp_channel *c = filp->private_data;
+
+	mutex_lock(&c->io_mutex);
+	while (c->dev && !ch_get_mbo(c, &mbo)) {
+		mutex_unlock(&c->io_mutex);
+
+		if ((filp->f_flags & O_NONBLOCK))
+			return -EAGAIN;
+		if (wait_event_interruptible(c->wq, ch_has_mbo(c) || !c->dev))
+			return -ERESTARTSYS;
+		mutex_lock(&c->io_mutex);
+	}
+
+	if (unlikely(!c->dev)) {
+		ret = -ENODEV;
+		goto unlock;
+	}
+
+	to_copy = min(count, c->cfg->buffer_size - c->mbo_offs);
+	left = copy_from_user(mbo->virt_address + c->mbo_offs, buf, to_copy);
+	if (left == to_copy) {
+		ret = -EFAULT;
+		goto unlock;
+	}
+
+	c->mbo_offs += to_copy - left;
+	if (c->mbo_offs >= c->cfg->buffer_size ||
+	    c->cfg->data_type == MOST_CH_CONTROL ||
+	    c->cfg->data_type == MOST_CH_ASYNC) {
+		kfifo_skip(&c->fifo);
+		mbo->buffer_length = c->mbo_offs;
+		c->mbo_offs = 0;
+		most_submit_mbo(mbo);
+	}
+
+	ret = to_copy - left;
+unlock:
+	mutex_unlock(&c->io_mutex);
+	return ret;
+}
+
+/**
+ * comp_read - implements the syscall to read from the device
+ * @filp: file pointer
+ * @buf: pointer to user buffer
+ * @count: number of bytes to read
+ * @offset: offset from where to start reading
+ */
+static ssize_t
+comp_read(struct file *filp, char __user *buf, size_t count, loff_t *offset)
+{
+	size_t to_copy, not_copied, copied;
+	struct mbo *mbo = NULL;
+	struct comp_channel *c = filp->private_data;
+
+	mutex_lock(&c->io_mutex);
+	while (c->dev && !kfifo_peek(&c->fifo, &mbo)) {
+		mutex_unlock(&c->io_mutex);
+		if (filp->f_flags & O_NONBLOCK)
+			return -EAGAIN;
+		if (wait_event_interruptible(c->wq,
+					     (!kfifo_is_empty(&c->fifo) ||
+					      (!c->dev))))
+			return -ERESTARTSYS;
+		mutex_lock(&c->io_mutex);
+	}
+
+	/* make sure we don't submit to gone devices */
+	if (unlikely(!c->dev)) {
+		mutex_unlock(&c->io_mutex);
+		return -ENODEV;
+	}
+
+	to_copy = min_t(size_t,
+			count,
+			mbo->processed_length - c->mbo_offs);
+
+	not_copied = copy_to_user(buf,
+				  mbo->virt_address + c->mbo_offs,
+				  to_copy);
+
+	copied = to_copy - not_copied;
+
+	c->mbo_offs += copied;
+	if (c->mbo_offs >= mbo->processed_length) {
+		kfifo_skip(&c->fifo);
+		most_put_mbo(mbo);
+		c->mbo_offs = 0;
+	}
+	mutex_unlock(&c->io_mutex);
+	return copied;
+}
+
+static __poll_t comp_poll(struct file *filp, poll_table *wait)
+{
+	struct comp_channel *c = filp->private_data;
+	__poll_t mask = 0;
+
+	poll_wait(filp, &c->wq, wait);
+
+	mutex_lock(&c->io_mutex);
+	if (c->cfg->direction == MOST_CH_RX) {
+		if (!c->dev || !kfifo_is_empty(&c->fifo))
+			mask |= EPOLLIN | EPOLLRDNORM;
+	} else {
+		if (!c->dev || !kfifo_is_empty(&c->fifo) || ch_has_mbo(c))
+			mask |= EPOLLOUT | EPOLLWRNORM;
+	}
+	mutex_unlock(&c->io_mutex);
+	return mask;
+}
+
+/*
+ * Initialization of struct file_operations
+ */
+static const struct file_operations channel_fops = {
+	.owner = THIS_MODULE,
+	.read = comp_read,
+	.write = comp_write,
+	.open = comp_open,
+	.release = comp_close,
+	.poll = comp_poll,
+};
+
+/**
+ * comp_disconnect_channel - disconnect a channel
+ * @iface: pointer to interface instance
+ * @channel_id: channel index
+ *
+ * This frees allocated memory and removes the cdev that represents this
+ * channel in user space.
+ */
+static int comp_disconnect_channel(struct most_interface *iface, int channel_id)
+{
+	struct comp_channel *c;
+
+	c = get_channel(iface, channel_id);
+	if (!c)
+		return -EINVAL;
+
+	mutex_lock(&c->io_mutex);
+	spin_lock(&c->unlink);
+	c->dev = NULL;
+	spin_unlock(&c->unlink);
+	destroy_cdev(c);
+	if (c->access_ref) {
+		stop_channel(c);
+		wake_up_interruptible(&c->wq);
+		mutex_unlock(&c->io_mutex);
+	} else {
+		mutex_unlock(&c->io_mutex);
+		destroy_channel(c);
+	}
+	return 0;
+}
+
+/**
+ * comp_rx_completion - completion handler for rx channels
+ * @mbo: pointer to buffer object that has completed
+ *
+ * This searches for the channel linked to this MBO and stores it in the local
+ * fifo buffer.
+ */
+static int comp_rx_completion(struct mbo *mbo)
+{
+	struct comp_channel *c;
+
+	if (!mbo)
+		return -EINVAL;
+
+	c = get_channel(mbo->ifp, mbo->hdm_channel_id);
+	if (!c)
+		return -EINVAL;
+
+	spin_lock(&c->unlink);
+	if (!c->access_ref || !c->dev) {
+		spin_unlock(&c->unlink);
+		return -ENODEV;
+	}
+	kfifo_in(&c->fifo, &mbo, 1);
+	spin_unlock(&c->unlink);
+#ifdef DEBUG_MESG
+	if (kfifo_is_full(&c->fifo))
+		dev_warn(c->dev, "Fifo is full\n");
+#endif
+	wake_up_interruptible(&c->wq);
+	return 0;
+}
+
+/**
+ * comp_tx_completion - completion handler for tx channels
+ * @iface: pointer to interface instance
+ * @channel_id: channel index/ID
+ *
+ * This wakes sleeping processes in the wait-queue.
+ */
+static int comp_tx_completion(struct most_interface *iface, int channel_id)
+{
+	struct comp_channel *c;
+
+	c = get_channel(iface, channel_id);
+	if (!c)
+		return -EINVAL;
+
+	if ((channel_id < 0) || (channel_id >= iface->num_channels)) {
+		dev_warn(c->dev, "Channel ID out of range\n");
+		return -EINVAL;
+	}
+
+	wake_up_interruptible(&c->wq);
+	return 0;
+}
+
+/**
+ * comp_probe - probe function of the driver module
+ * @iface: pointer to interface instance
+ * @channel_id: channel index/ID
+ * @cfg: pointer to actual channel configuration
+ * @name: name of the device to be created
+ * @args: pointer to array of component parameters (from configfs)
+ *
+ * This allocates a channel object and creates the device node in /dev
+ *
+ * Returns 0 on success or error code otherwise.
+ */
+static int comp_probe(struct most_interface *iface, int channel_id,
+		      struct most_channel_config *cfg, char *name, char *args)
+{
+	struct comp_channel *c;
+	unsigned long cl_flags;
+	int retval;
+	int current_minor;
+
+	if (!cfg || !name)
+		return -EINVAL;
+
+	c = get_channel(iface, channel_id);
+	if (c)
+		return -EEXIST;
+
+	current_minor = ida_alloc(&comp.minor_id, GFP_KERNEL);
+	if (current_minor < 0)
+		return current_minor;
+
+	c = kzalloc_obj(*c);
+	if (!c) {
+		retval = -ENOMEM;
+		goto err_remove_ida;
+	}
+
+	c->devno = MKDEV(comp.major, current_minor);
+	cdev_init(&c->cdev, &channel_fops);
+	c->cdev.owner = THIS_MODULE;
+	retval = cdev_add(&c->cdev, c->devno, 1);
+	if (retval < 0)
+		goto err_free_c;
+	c->iface = iface;
+	c->cfg = cfg;
+	c->channel_id = channel_id;
+	c->access_ref = 0;
+	spin_lock_init(&c->unlink);
+	INIT_KFIFO(c->fifo);
+	retval = kfifo_alloc(&c->fifo, cfg->num_buffers, GFP_KERNEL);
+	if (retval)
+		goto err_del_cdev_and_free_channel;
+	init_waitqueue_head(&c->wq);
+	mutex_init(&c->io_mutex);
+	spin_lock_irqsave(&ch_list_lock, cl_flags);
+	list_add_tail(&c->list, &channel_list);
+	spin_unlock_irqrestore(&ch_list_lock, cl_flags);
+	c->dev = device_create(&most_cdev_class, NULL, c->devno, NULL, "%s", name);
+
+	if (IS_ERR(c->dev)) {
+		retval = PTR_ERR(c->dev);
+		goto err_free_kfifo_and_del_list;
+	}
+	kobject_uevent(&c->dev->kobj, KOBJ_ADD);
+	return 0;
+
+err_free_kfifo_and_del_list:
+	kfifo_free(&c->fifo);
+	list_del(&c->list);
+err_del_cdev_and_free_channel:
+	cdev_del(&c->cdev);
+err_free_c:
+	kfree(c);
+err_remove_ida:
+	ida_free(&comp.minor_id, current_minor);
+	return retval;
+}
+
+static struct cdev_component comp = {
+	.cc = {
+		.mod = THIS_MODULE,
+		.name = "cdev",
+		.probe_channel = comp_probe,
+		.disconnect_channel = comp_disconnect_channel,
+		.rx_completion = comp_rx_completion,
+		.tx_completion = comp_tx_completion,
+	},
+};
+
+
+static int __init most_cdev_init(void)
+{
+	int err;
+
+	err = class_register(&most_cdev_class);
+	if (err)
+		return err;
+
+	ida_init(&comp.minor_id);
+
+	err = alloc_chrdev_region(&comp.devno, 0, CHRDEV_REGION_SIZE, "cdev");
+	if (err < 0)
+		goto dest_ida;
+	comp.major = MAJOR(comp.devno);
+	err = most_register_component(&comp.cc);
+	if (err)
+		goto free_cdev;
+	err = most_register_configfs_subsys(&comp.cc);
+	if (err)
+		goto deregister_comp;
+	return 0;
+
+deregister_comp:
+	most_deregister_component(&comp.cc);
+free_cdev:
+	unregister_chrdev_region(comp.devno, CHRDEV_REGION_SIZE);
+dest_ida:
+	ida_destroy(&comp.minor_id);
+	class_unregister(&most_cdev_class);
+	return err;
+}
+
+static void __exit most_cdev_exit(void)
+{
+	struct comp_channel *c, *tmp;
+
+	most_deregister_configfs_subsys(&comp.cc);
+	most_deregister_component(&comp.cc);
+
+	list_for_each_entry_safe(c, tmp, &channel_list, list) {
+		destroy_cdev(c);
+		destroy_channel(c);
+	}
+	unregister_chrdev_region(comp.devno, CHRDEV_REGION_SIZE);
+	ida_destroy(&comp.minor_id);
+	class_unregister(&most_cdev_class);
+}
+
+module_init(most_cdev_init);
+module_exit(most_cdev_exit);
+MODULE_AUTHOR("Christian Gromm <christian.gromm@microchip.com>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("character device component for mostcore");

linux-7.2.3/drivers/most/most_snd.c

@@ -0,0 +1,747 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * sound.c - Sound component for Mostcore
+ *
+ * Copyright (C) 2015 Microchip Technology Germany II GmbH & Co. KG
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/printk.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <linux/sched.h>
+#include <linux/kthread.h>
+#include <linux/most.h>
+
+#define DRIVER_NAME "sound"
+#define STRING_SIZE	80
+
+static struct most_component comp;
+
+/**
+ * struct channel - private structure to keep channel specific data
+ * @substream: stores the substream structure
+ * @pcm_hardware: low-level hardware description
+ * @iface: interface for which the channel belongs to
+ * @cfg: channel configuration
+ * @card: registered sound card
+ * @list: list for private use
+ * @id: channel index
+ * @period_pos: current period position (ring buffer)
+ * @buffer_pos: current buffer position (ring buffer)
+ * @is_stream_running: identifies whether a stream is running or not
+ * @opened: set when the stream is opened
+ * @playback_task: playback thread
+ * @playback_waitq: waitq used by playback thread
+ * @copy_fn: copy function for PCM-specific format and width
+ */
+struct channel {
+	struct snd_pcm_substream *substream;
+	struct snd_pcm_hardware pcm_hardware;
+	struct most_interface *iface;
+	struct most_channel_config *cfg;
+	struct snd_card *card;
+	struct list_head list;
+	int id;
+	unsigned int period_pos;
+	unsigned int buffer_pos;
+	bool is_stream_running;
+	struct task_struct *playback_task;
+	wait_queue_head_t playback_waitq;
+	void (*copy_fn)(void *alsa, void *most, unsigned int bytes);
+};
+
+struct sound_adapter {
+	struct list_head dev_list;
+	struct most_interface *iface;
+	struct snd_card *card;
+	struct list_head list;
+	bool registered;
+	int pcm_dev_idx;
+};
+
+static struct list_head adpt_list;
+
+#define MOST_PCM_INFO (SNDRV_PCM_INFO_MMAP | \
+		       SNDRV_PCM_INFO_MMAP_VALID | \
+		       SNDRV_PCM_INFO_BATCH | \
+		       SNDRV_PCM_INFO_INTERLEAVED | \
+		       SNDRV_PCM_INFO_BLOCK_TRANSFER)
+
+static void swap_copy16(u16 *dest, const u16 *source, unsigned int bytes)
+{
+	unsigned int i = 0;
+
+	while (i < (bytes / 2)) {
+		dest[i] = swab16(source[i]);
+		i++;
+	}
+}
+
+static void swap_copy24(u8 *dest, const u8 *source, unsigned int bytes)
+{
+	unsigned int i = 0;
+
+	if (bytes < 2)
+		return;
+	while (i < bytes - 2) {
+		dest[i] = source[i + 2];
+		dest[i + 1] = source[i + 1];
+		dest[i + 2] = source[i];
+		i += 3;
+	}
+}
+
+static void swap_copy32(u32 *dest, const u32 *source, unsigned int bytes)
+{
+	unsigned int i = 0;
+
+	while (i < bytes / 4) {
+		dest[i] = swab32(source[i]);
+		i++;
+	}
+}
+
+static void alsa_to_most_memcpy(void *alsa, void *most, unsigned int bytes)
+{
+	memcpy(most, alsa, bytes);
+}
+
+static void alsa_to_most_copy16(void *alsa, void *most, unsigned int bytes)
+{
+	swap_copy16(most, alsa, bytes);
+}
+
+static void alsa_to_most_copy24(void *alsa, void *most, unsigned int bytes)
+{
+	swap_copy24(most, alsa, bytes);
+}
+
+static void alsa_to_most_copy32(void *alsa, void *most, unsigned int bytes)
+{
+	swap_copy32(most, alsa, bytes);
+}
+
+static void most_to_alsa_memcpy(void *alsa, void *most, unsigned int bytes)
+{
+	memcpy(alsa, most, bytes);
+}
+
+static void most_to_alsa_copy16(void *alsa, void *most, unsigned int bytes)
+{
+	swap_copy16(alsa, most, bytes);
+}
+
+static void most_to_alsa_copy24(void *alsa, void *most, unsigned int bytes)
+{
+	swap_copy24(alsa, most, bytes);
+}
+
+static void most_to_alsa_copy32(void *alsa, void *most, unsigned int bytes)
+{
+	swap_copy32(alsa, most, bytes);
+}
+
+/**
+ * get_channel - get pointer to channel
+ * @iface: interface structure
+ * @channel_id: channel ID
+ *
+ * This traverses the channel list and returns the channel matching the
+ * ID and interface.
+ *
+ * Returns pointer to channel on success or NULL otherwise.
+ */
+static struct channel *get_channel(struct most_interface *iface,
+				   int channel_id)
+{
+	struct sound_adapter *adpt = iface->priv;
+	struct channel *channel;
+
+	list_for_each_entry(channel, &adpt->dev_list, list) {
+		if ((channel->iface == iface) && (channel->id == channel_id))
+			return channel;
+	}
+	return NULL;
+}
+
+/**
+ * copy_data - implements data copying function
+ * @channel: channel
+ * @mbo: MBO from core
+ *
+ * Copy data from/to ring buffer to/from MBO and update the buffer position
+ */
+static bool copy_data(struct channel *channel, struct mbo *mbo)
+{
+	struct snd_pcm_runtime *const runtime = channel->substream->runtime;
+	unsigned int const frame_bytes = channel->cfg->subbuffer_size;
+	unsigned int const buffer_size = runtime->buffer_size;
+	unsigned int frames;
+	unsigned int fr0;
+
+	if (channel->cfg->direction & MOST_CH_RX)
+		frames = mbo->processed_length / frame_bytes;
+	else
+		frames = mbo->buffer_length / frame_bytes;
+	fr0 = min(buffer_size - channel->buffer_pos, frames);
+
+	channel->copy_fn(runtime->dma_area + channel->buffer_pos * frame_bytes,
+			 mbo->virt_address,
+			 fr0 * frame_bytes);
+
+	if (frames > fr0) {
+		/* wrap around at end of ring buffer */
+		channel->copy_fn(runtime->dma_area,
+				 mbo->virt_address + fr0 * frame_bytes,
+				 (frames - fr0) * frame_bytes);
+	}
+
+	channel->buffer_pos += frames;
+	if (channel->buffer_pos >= buffer_size)
+		channel->buffer_pos -= buffer_size;
+	channel->period_pos += frames;
+	if (channel->period_pos >= runtime->period_size) {
+		channel->period_pos -= runtime->period_size;
+		return true;
+	}
+	return false;
+}
+
+/**
+ * playback_thread - function implements the playback thread
+ * @data: private data
+ *
+ * Thread which does the playback functionality in a loop. It waits for a free
+ * MBO from mostcore for a particular channel and copy the data from ring buffer
+ * to MBO. Submit the MBO back to mostcore, after copying the data.
+ *
+ * Returns 0 on success or error code otherwise.
+ */
+static int playback_thread(void *data)
+{
+	struct channel *const channel = data;
+
+	while (!kthread_should_stop()) {
+		struct mbo *mbo = NULL;
+		bool period_elapsed = false;
+
+		wait_event_interruptible(
+			channel->playback_waitq,
+			kthread_should_stop() ||
+			(channel->is_stream_running &&
+			 (mbo = most_get_mbo(channel->iface, channel->id,
+					     &comp))));
+		if (!mbo)
+			continue;
+
+		if (channel->is_stream_running)
+			period_elapsed = copy_data(channel, mbo);
+		else
+			memset(mbo->virt_address, 0, mbo->buffer_length);
+
+		most_submit_mbo(mbo);
+		if (period_elapsed)
+			snd_pcm_period_elapsed(channel->substream);
+	}
+	return 0;
+}
+
+/**
+ * pcm_open - implements open callback function for PCM middle layer
+ * @substream: pointer to ALSA PCM substream
+ *
+ * This is called when a PCM substream is opened. At least, the function should
+ * initialize the runtime->hw record.
+ *
+ * Returns 0 on success or error code otherwise.
+ */
+static int pcm_open(struct snd_pcm_substream *substream)
+{
+	struct channel *channel = substream->private_data;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct most_channel_config *cfg = channel->cfg;
+	int ret;
+
+	channel->substream = substream;
+
+	if (cfg->direction == MOST_CH_TX) {
+		channel->playback_task = kthread_run(playback_thread, channel,
+						     "most_audio_playback");
+		if (IS_ERR(channel->playback_task)) {
+			pr_err("Couldn't start thread\n");
+			return PTR_ERR(channel->playback_task);
+		}
+	}
+
+	ret = most_start_channel(channel->iface, channel->id, &comp);
+	if (ret) {
+		pr_err("most_start_channel() failed!\n");
+		if (cfg->direction == MOST_CH_TX)
+			kthread_stop(channel->playback_task);
+		return ret;
+	}
+
+	runtime->hw = channel->pcm_hardware;
+	return 0;
+}
+
+/**
+ * pcm_close - implements close callback function for PCM middle layer
+ * @substream: sub-stream pointer
+ *
+ * Obviously, this is called when a PCM substream is closed. Any private
+ * instance for a PCM substream allocated in the open callback will be
+ * released here.
+ *
+ * Returns 0 on success or error code otherwise.
+ */
+static int pcm_close(struct snd_pcm_substream *substream)
+{
+	struct channel *channel = substream->private_data;
+
+	if (channel->cfg->direction == MOST_CH_TX)
+		kthread_stop(channel->playback_task);
+	most_stop_channel(channel->iface, channel->id, &comp);
+	return 0;
+}
+
+/**
+ * pcm_prepare - implements prepare callback function for PCM middle layer
+ * @substream: substream pointer
+ *
+ * This callback is called when the PCM is "prepared". Format rate, sample rate,
+ * etc., can be set here. This callback can be called many times at each setup.
+ *
+ * Returns 0 on success or error code otherwise.
+ */
+static int pcm_prepare(struct snd_pcm_substream *substream)
+{
+	struct channel *channel = substream->private_data;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct most_channel_config *cfg = channel->cfg;
+	int width = snd_pcm_format_physical_width(runtime->format);
+
+	channel->copy_fn = NULL;
+
+	if (cfg->direction == MOST_CH_TX) {
+		if (snd_pcm_format_big_endian(runtime->format) || width == 8)
+			channel->copy_fn = alsa_to_most_memcpy;
+		else if (width == 16)
+			channel->copy_fn = alsa_to_most_copy16;
+		else if (width == 24)
+			channel->copy_fn = alsa_to_most_copy24;
+		else if (width == 32)
+			channel->copy_fn = alsa_to_most_copy32;
+	} else {
+		if (snd_pcm_format_big_endian(runtime->format) || width == 8)
+			channel->copy_fn = most_to_alsa_memcpy;
+		else if (width == 16)
+			channel->copy_fn = most_to_alsa_copy16;
+		else if (width == 24)
+			channel->copy_fn = most_to_alsa_copy24;
+		else if (width == 32)
+			channel->copy_fn = most_to_alsa_copy32;
+	}
+
+	if (!channel->copy_fn)
+		return -EINVAL;
+	channel->period_pos = 0;
+	channel->buffer_pos = 0;
+	return 0;
+}
+
+/**
+ * pcm_trigger - implements trigger callback function for PCM middle layer
+ * @substream: substream pointer
+ * @cmd: action to perform
+ *
+ * This is called when the PCM is started, stopped or paused. The action will be
+ * specified in the second argument, SNDRV_PCM_TRIGGER_XXX
+ *
+ * Returns 0 on success or error code otherwise.
+ */
+static int pcm_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	struct channel *channel = substream->private_data;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+		channel->is_stream_running = true;
+		wake_up_interruptible(&channel->playback_waitq);
+		return 0;
+
+	case SNDRV_PCM_TRIGGER_STOP:
+		channel->is_stream_running = false;
+		return 0;
+
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+/**
+ * pcm_pointer - implements pointer callback function for PCM middle layer
+ * @substream: substream pointer
+ *
+ * This callback is called when the PCM middle layer inquires the current
+ * hardware position on the buffer. The position must be returned in frames,
+ * ranging from 0 to buffer_size-1.
+ */
+static snd_pcm_uframes_t pcm_pointer(struct snd_pcm_substream *substream)
+{
+	struct channel *channel = substream->private_data;
+
+	return channel->buffer_pos;
+}
+
+/*
+ * Initialization of struct snd_pcm_ops
+ */
+static const struct snd_pcm_ops pcm_ops = {
+	.open       = pcm_open,
+	.close      = pcm_close,
+	.prepare    = pcm_prepare,
+	.trigger    = pcm_trigger,
+	.pointer    = pcm_pointer,
+};
+
+static int split_arg_list(char *buf, u16 *ch_num, char **sample_res)
+{
+	char *num;
+	int ret;
+
+	num = strsep(&buf, "x");
+	if (!num)
+		goto err;
+	ret = kstrtou16(num, 0, ch_num);
+	if (ret)
+		goto err;
+	*sample_res = strsep(&buf, ".\n");
+	if (!*sample_res)
+		goto err;
+	return 0;
+
+err:
+	pr_err("Bad PCM format\n");
+	return -EINVAL;
+}
+
+static const struct sample_resolution_info {
+	const char *sample_res;
+	int bytes;
+	u64 formats;
+} sinfo[] = {
+	{ "8", 1, SNDRV_PCM_FMTBIT_S8 },
+	{ "16", 2, SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE },
+	{ "24", 3, SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_3BE },
+	{ "32", 4, SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE },
+};
+
+static int audio_set_hw_params(struct snd_pcm_hardware *pcm_hw,
+			       u16 ch_num, char *sample_res,
+			       struct most_channel_config *cfg)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(sinfo); i++) {
+		if (!strcmp(sample_res, sinfo[i].sample_res))
+			goto found;
+	}
+	pr_err("Unsupported PCM format\n");
+	return -EINVAL;
+
+found:
+	if (!ch_num) {
+		pr_err("Bad number of channels\n");
+		return -EINVAL;
+	}
+
+	if (cfg->subbuffer_size != ch_num * sinfo[i].bytes) {
+		pr_err("Audio resolution doesn't fit subbuffer size\n");
+		return -EINVAL;
+	}
+
+	pcm_hw->info = MOST_PCM_INFO;
+	pcm_hw->rates = SNDRV_PCM_RATE_48000;
+	pcm_hw->rate_min = 48000;
+	pcm_hw->rate_max = 48000;
+	pcm_hw->buffer_bytes_max = cfg->num_buffers * cfg->buffer_size;
+	pcm_hw->period_bytes_min = cfg->buffer_size;
+	pcm_hw->period_bytes_max = cfg->buffer_size;
+	pcm_hw->periods_min = 1;
+	pcm_hw->periods_max = cfg->num_buffers;
+	pcm_hw->channels_min = ch_num;
+	pcm_hw->channels_max = ch_num;
+	pcm_hw->formats = sinfo[i].formats;
+	return 0;
+}
+
+static void release_adapter(struct sound_adapter *adpt)
+{
+	struct channel *channel, *tmp;
+
+	list_for_each_entry_safe(channel, tmp, &adpt->dev_list, list) {
+		list_del(&channel->list);
+		kfree(channel);
+	}
+	if (adpt->card)
+		snd_card_free(adpt->card);
+	list_del(&adpt->list);
+	kfree(adpt);
+}
+
+/**
+ * audio_probe_channel - probe function of the driver module
+ * @iface: pointer to interface instance
+ * @channel_id: channel index/ID
+ * @cfg: pointer to actual channel configuration
+ * @device_name: name of the device to be created in /dev
+ * @arg_list: string that provides the desired audio resolution
+ *
+ * Creates sound card, pcm device, sets pcm ops and registers sound card.
+ *
+ * Returns 0 on success or error code otherwise.
+ */
+static int audio_probe_channel(struct most_interface *iface, int channel_id,
+			       struct most_channel_config *cfg,
+			       char *device_name, char *arg_list)
+{
+	struct channel *channel;
+	struct sound_adapter *adpt;
+	struct snd_pcm *pcm;
+	int playback_count = 0;
+	int capture_count = 0;
+	int ret;
+	int direction;
+	u16 ch_num;
+	char *sample_res;
+	char arg_list_cpy[STRING_SIZE];
+
+	if (cfg->data_type != MOST_CH_SYNC) {
+		pr_err("Incompatible channel type\n");
+		return -EINVAL;
+	}
+	strscpy(arg_list_cpy, arg_list, STRING_SIZE);
+	ret = split_arg_list(arg_list_cpy, &ch_num, &sample_res);
+	if (ret < 0)
+		return ret;
+
+	list_for_each_entry(adpt, &adpt_list, list) {
+		if (adpt->iface != iface)
+			continue;
+		if (adpt->registered)
+			return -ENOSPC;
+		adpt->pcm_dev_idx++;
+		goto skip_adpt_alloc;
+	}
+	adpt = kzalloc_obj(*adpt);
+	if (!adpt)
+		return -ENOMEM;
+
+	adpt->iface = iface;
+	INIT_LIST_HEAD(&adpt->dev_list);
+	iface->priv = adpt;
+	list_add_tail(&adpt->list, &adpt_list);
+	ret = snd_card_new(iface->driver_dev, -1, "INIC", THIS_MODULE,
+			   sizeof(*channel), &adpt->card);
+	if (ret < 0)
+		goto err_free_adpt;
+	snprintf(adpt->card->driver, sizeof(adpt->card->driver),
+		 "%s", DRIVER_NAME);
+	snprintf(adpt->card->shortname, sizeof(adpt->card->shortname),
+		 "Microchip INIC");
+	snprintf(adpt->card->longname, sizeof(adpt->card->longname),
+		 "%s at %s", adpt->card->shortname, iface->description);
+skip_adpt_alloc:
+	if (get_channel(iface, channel_id)) {
+		pr_err("channel (%s:%d) is already linked\n",
+		       iface->description, channel_id);
+		return -EEXIST;
+	}
+
+	if (cfg->direction == MOST_CH_TX) {
+		playback_count = 1;
+		direction = SNDRV_PCM_STREAM_PLAYBACK;
+	} else {
+		capture_count = 1;
+		direction = SNDRV_PCM_STREAM_CAPTURE;
+	}
+	channel = kzalloc_obj(*channel);
+	if (!channel) {
+		ret = -ENOMEM;
+		goto err_free_adpt;
+	}
+	channel->card = adpt->card;
+	channel->cfg = cfg;
+	channel->iface = iface;
+	channel->id = channel_id;
+	init_waitqueue_head(&channel->playback_waitq);
+	list_add_tail(&channel->list, &adpt->dev_list);
+
+	ret = audio_set_hw_params(&channel->pcm_hardware, ch_num, sample_res,
+				  cfg);
+	if (ret)
+		goto err_free_adpt;
+
+	ret = snd_pcm_new(adpt->card, device_name, adpt->pcm_dev_idx,
+			  playback_count, capture_count, &pcm);
+
+	if (ret < 0)
+		goto err_free_adpt;
+
+	pcm->private_data = channel;
+	strscpy(pcm->name, device_name, sizeof(pcm->name));
+	snd_pcm_set_ops(pcm, direction, &pcm_ops);
+	snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_VMALLOC, NULL, 0, 0);
+	return 0;
+
+err_free_adpt:
+	release_adapter(adpt);
+	return ret;
+}
+
+static int audio_create_sound_card(void)
+{
+	int ret;
+	struct sound_adapter *adpt;
+
+	list_for_each_entry(adpt, &adpt_list, list) {
+		if (!adpt->registered)
+			goto adpt_alloc;
+	}
+	return -ENODEV;
+adpt_alloc:
+	ret = snd_card_register(adpt->card);
+	if (ret < 0) {
+		release_adapter(adpt);
+		return ret;
+	}
+	adpt->registered = true;
+	return 0;
+}
+
+/**
+ * audio_disconnect_channel - function to disconnect a channel
+ * @iface: pointer to interface instance
+ * @channel_id: channel index
+ *
+ * This frees allocated memory and removes the sound card from ALSA
+ *
+ * Returns 0 on success or error code otherwise.
+ */
+static int audio_disconnect_channel(struct most_interface *iface,
+				    int channel_id)
+{
+	struct channel *channel;
+	struct sound_adapter *adpt = iface->priv;
+
+	channel = get_channel(iface, channel_id);
+	if (!channel)
+		return -EINVAL;
+
+	list_del(&channel->list);
+
+	kfree(channel);
+	if (list_empty(&adpt->dev_list))
+		release_adapter(adpt);
+	return 0;
+}
+
+/**
+ * audio_rx_completion - completion handler for rx channels
+ * @mbo: pointer to buffer object that has completed
+ *
+ * This searches for the channel this MBO belongs to and copy the data from MBO
+ * to ring buffer
+ *
+ * Returns 0 on success or error code otherwise.
+ */
+static int audio_rx_completion(struct mbo *mbo)
+{
+	struct channel *channel = get_channel(mbo->ifp, mbo->hdm_channel_id);
+	bool period_elapsed = false;
+
+	if (!channel)
+		return -EINVAL;
+	if (channel->is_stream_running)
+		period_elapsed = copy_data(channel, mbo);
+	most_put_mbo(mbo);
+	if (period_elapsed)
+		snd_pcm_period_elapsed(channel->substream);
+	return 0;
+}
+
+/**
+ * audio_tx_completion - completion handler for tx channels
+ * @iface: pointer to interface instance
+ * @channel_id: channel index/ID
+ *
+ * This searches the channel that belongs to this combination of interface
+ * pointer and channel ID and wakes a process sitting in the wait queue of
+ * this channel.
+ *
+ * Returns 0 on success or error code otherwise.
+ */
+static int audio_tx_completion(struct most_interface *iface, int channel_id)
+{
+	struct channel *channel = get_channel(iface, channel_id);
+
+	if (!channel)
+		return -EINVAL;
+
+	wake_up_interruptible(&channel->playback_waitq);
+	return 0;
+}
+
+/*
+ * Initialization of the struct most_component
+ */
+static struct most_component comp = {
+	.mod = THIS_MODULE,
+	.name = DRIVER_NAME,
+	.probe_channel = audio_probe_channel,
+	.disconnect_channel = audio_disconnect_channel,
+	.rx_completion = audio_rx_completion,
+	.tx_completion = audio_tx_completion,
+	.cfg_complete = audio_create_sound_card,
+};
+
+static int __init audio_init(void)
+{
+	int ret;
+
+	INIT_LIST_HEAD(&adpt_list);
+
+	ret = most_register_component(&comp);
+	if (ret) {
+		pr_err("Failed to register %s\n", comp.name);
+		return ret;
+	}
+	ret = most_register_configfs_subsys(&comp);
+	if (ret) {
+		pr_err("Failed to register %s configfs subsys\n", comp.name);
+		most_deregister_component(&comp);
+	}
+	return ret;
+}
+
+static void __exit audio_exit(void)
+{
+	most_deregister_configfs_subsys(&comp);
+	most_deregister_component(&comp);
+}
+
+module_init(audio_init);
+module_exit(audio_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Christian Gromm <christian.gromm@microchip.com>");
+MODULE_DESCRIPTION("Sound Component Module for Mostcore");