staging: most: move core files out of the staging area

This patch moves the core module to the /drivers/most directory
and makes all necessary changes in order to not break the build.

Signed-off-by: Christian Gromm <christian.gromm@microchip.com>
Link: https://lore.kernel.org/r/1583845362-26707-2-git-send-email-christian.gromm@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

4 files changed, 2233 insertions, 0 deletions

diff --git a/drivers/most/Kconfig b/drivers/most/Kconfig
new file mode 100644
index 000000000000..58d7999170a7
--- /dev/null
+++ b/drivers/most/Kconfig
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0
+menuconfig MOST
+	tristate "MOST 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.
diff --git a/drivers/most/Makefile b/drivers/most/Makefile
new file mode 100644
index 000000000000..e810cd3a47ee
--- /dev/null
+++ b/drivers/most/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_MOST) += most_core.o
+most_core-y :=	core.o \
+		configfs.o
diff --git a/drivers/most/configfs.c b/drivers/most/configfs.c
new file mode 100644
index 000000000000..27b0c923597f
--- /dev/null
+++ b/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);
+
+	strlcpy(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);
+
+	strlcpy(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);
+
+	strlcpy(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);
+
+	strlcpy(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(sizeof(*mdev_link), GFP_KERNEL);
+	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(sizeof(*mdev_link), GFP_KERNEL);
+	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(sizeof(*most), GFP_KERNEL);
+	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;
+}
diff --git a/drivers/most/core.c b/drivers/most/core.c
new file mode 100644
index 000000000000..06426fc5c990
--- /dev/null
+++ b/drivers/most/core.c
@@ -0,0 +1,1490 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * core.c - Implementation of core module of MOST Linux driver stack
+ *
+ * Copyright (C) 2013-2020 Microchip Technology Germany II GmbH & Co. KG
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/poll.h>
+#include <linux/wait.h>
+#include <linux/kobject.h>
+#include <linux/mutex.h>
+#include <linux/completion.h>
+#include <linux/sysfs.h>
+#include <linux/kthread.h>
+#include <linux/dma-mapping.h>
+#include <linux/idr.h>
+#include <linux/most.h>
+
+#define MAX_CHANNELS	64
+#define STRING_SIZE	80
+
+static struct ida mdev_id;
+static int dummy_num_buffers;
+static struct list_head comp_list;
+
+struct pipe {
+	struct most_component *comp;
+	int refs;
+	int num_buffers;
+};
+
+struct most_channel {
+	struct device dev;
+	struct completion cleanup;
+	atomic_t mbo_ref;
+	atomic_t mbo_nq_level;
+	u16 channel_id;
+	char name[STRING_SIZE];
+	bool is_poisoned;
+	struct mutex start_mutex; /* channel activation synchronization */
+	struct mutex nq_mutex; /* nq thread synchronization */
+	int is_starving;
+	struct most_interface *iface;
+	struct most_channel_config cfg;
+	bool keep_mbo;
+	bool enqueue_halt;
+	struct list_head fifo;
+	spinlock_t fifo_lock; /* fifo access synchronization */
+	struct list_head halt_fifo;
+	struct list_head list;
+	struct pipe pipe0;
+	struct pipe pipe1;
+	struct list_head trash_fifo;
+	struct task_struct *hdm_enqueue_task;
+	wait_queue_head_t hdm_fifo_wq;
+
+};
+
+#define to_channel(d) container_of(d, struct most_channel, dev)
+
+struct interface_private {
+	int dev_id;
+	char name[STRING_SIZE];
+	struct most_channel *channel[MAX_CHANNELS];
+	struct list_head channel_list;
+};
+
+static const struct {
+	int most_ch_data_type;
+	const char *name;
+} ch_data_type[] = {
+	{ MOST_CH_CONTROL, "control" },
+	{ MOST_CH_ASYNC, "async" },
+	{ MOST_CH_SYNC, "sync" },
+	{ MOST_CH_ISOC, "isoc"},
+	{ MOST_CH_ISOC, "isoc_avp"},
+};
+
+/**
+ * list_pop_mbo - retrieves the first MBO of the list and removes it
+ * @ptr: the list head to grab the MBO from.
+ */
+#define list_pop_mbo(ptr)						\
+({									\
+	struct mbo *_mbo = list_first_entry(ptr, struct mbo, list);	\
+	list_del(&_mbo->list);						\
+	_mbo;								\
+})
+
+/**
+ * most_free_mbo_coherent - free an MBO and its coherent buffer
+ * @mbo: most buffer
+ */
+static void most_free_mbo_coherent(struct mbo *mbo)
+{
+	struct most_channel *c = mbo->context;
+	u16 const coherent_buf_size = c->cfg.buffer_size + c->cfg.extra_len;
+
+	if (c->iface->dma_free)
+		c->iface->dma_free(mbo, coherent_buf_size);
+	else
+		kfree(mbo->virt_address);
+	kfree(mbo);
+	if (atomic_sub_and_test(1, &c->mbo_ref))
+		complete(&c->cleanup);
+}
+
+/**
+ * flush_channel_fifos - clear the channel fifos
+ * @c: pointer to channel object
+ */
+static void flush_channel_fifos(struct most_channel *c)
+{
+	unsigned long flags, hf_flags;
+	struct mbo *mbo, *tmp;
+
+	if (list_empty(&c->fifo) && list_empty(&c->halt_fifo))
+		return;
+
+	spin_lock_irqsave(&c->fifo_lock, flags);
+	list_for_each_entry_safe(mbo, tmp, &c->fifo, list) {
+		list_del(&mbo->list);
+		spin_unlock_irqrestore(&c->fifo_lock, flags);
+		most_free_mbo_coherent(mbo);
+		spin_lock_irqsave(&c->fifo_lock, flags);
+	}
+	spin_unlock_irqrestore(&c->fifo_lock, flags);
+
+	spin_lock_irqsave(&c->fifo_lock, hf_flags);
+	list_for_each_entry_safe(mbo, tmp, &c->halt_fifo, list) {
+		list_del(&mbo->list);
+		spin_unlock_irqrestore(&c->fifo_lock, hf_flags);
+		most_free_mbo_coherent(mbo);
+		spin_lock_irqsave(&c->fifo_lock, hf_flags);
+	}
+	spin_unlock_irqrestore(&c->fifo_lock, hf_flags);
+
+	if (unlikely((!list_empty(&c->fifo) || !list_empty(&c->halt_fifo))))
+		dev_warn(&c->dev, "Channel or trash fifo not empty\n");
+}
+
+/**
+ * flush_trash_fifo - clear the trash fifo
+ * @c: pointer to channel object
+ */
+static int flush_trash_fifo(struct most_channel *c)
+{
+	struct mbo *mbo, *tmp;
+	unsigned long flags;
+
+	spin_lock_irqsave(&c->fifo_lock, flags);
+	list_for_each_entry_safe(mbo, tmp, &c->trash_fifo, list) {
+		list_del(&mbo->list);
+		spin_unlock_irqrestore(&c->fifo_lock, flags);
+		most_free_mbo_coherent(mbo);
+		spin_lock_irqsave(&c->fifo_lock, flags);
+	}
+	spin_unlock_irqrestore(&c->fifo_lock, flags);
+	return 0;
+}
+
+static ssize_t available_directions_show(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	struct most_channel *c = to_channel(dev);
+	unsigned int i = c->channel_id;
+
+	strcpy(buf, "");
+	if (c->iface->channel_vector[i].direction & MOST_CH_RX)
+		strcat(buf, "rx ");
+	if (c->iface->channel_vector[i].direction & MOST_CH_TX)
+		strcat(buf, "tx ");
+	strcat(buf, "\n");
+	return strlen(buf);
+}
+
+static ssize_t available_datatypes_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct most_channel *c = to_channel(dev);
+	unsigned int i = c->channel_id;
+
+	strcpy(buf, "");
+	if (c->iface->channel_vector[i].data_type & MOST_CH_CONTROL)
+		strcat(buf, "control ");
+	if (c->iface->channel_vector[i].data_type & MOST_CH_ASYNC)
+		strcat(buf, "async ");
+	if (c->iface->channel_vector[i].data_type & MOST_CH_SYNC)
+		strcat(buf, "sync ");
+	if (c->iface->channel_vector[i].data_type & MOST_CH_ISOC)
+		strcat(buf, "isoc ");
+	strcat(buf, "\n");
+	return strlen(buf);
+}
+
+static ssize_t number_of_packet_buffers_show(struct device *dev,
+					     struct device_attribute *attr,
+					     char *buf)
+{
+	struct most_channel *c = to_channel(dev);
+	unsigned int i = c->channel_id;
+
+	return snprintf(buf, PAGE_SIZE, "%d\n",
+			c->iface->channel_vector[i].num_buffers_packet);
+}
+
+static ssize_t number_of_stream_buffers_show(struct device *dev,
+					     struct device_attribute *attr,
+					     char *buf)
+{
+	struct most_channel *c = to_channel(dev);
+	unsigned int i = c->channel_id;
+
+	return snprintf(buf, PAGE_SIZE, "%d\n",
+			c->iface->channel_vector[i].num_buffers_streaming);
+}
+
+static ssize_t size_of_packet_buffer_show(struct device *dev,
+					  struct device_attribute *attr,
+					  char *buf)
+{
+	struct most_channel *c = to_channel(dev);
+	unsigned int i = c->channel_id;
+
+	return snprintf(buf, PAGE_SIZE, "%d\n",
+			c->iface->channel_vector[i].buffer_size_packet);
+}
+
+static ssize_t size_of_stream_buffer_show(struct device *dev,
+					  struct device_attribute *attr,
+					  char *buf)
+{
+	struct most_channel *c = to_channel(dev);
+	unsigned int i = c->channel_id;
+
+	return snprintf(buf, PAGE_SIZE, "%d\n",
+			c->iface->channel_vector[i].buffer_size_streaming);
+}
+
+static ssize_t channel_starving_show(struct device *dev,
+				     struct device_attribute *attr,
+				     char *buf)
+{
+	struct most_channel *c = to_channel(dev);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", c->is_starving);
+}
+
+static ssize_t set_number_of_buffers_show(struct device *dev,
+					  struct device_attribute *attr,
+					  char *buf)
+{
+	struct most_channel *c = to_channel(dev);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", c->cfg.num_buffers);
+}
+
+static ssize_t set_buffer_size_show(struct device *dev,
+				    struct device_attribute *attr,
+				    char *buf)
+{
+	struct most_channel *c = to_channel(dev);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", c->cfg.buffer_size);
+}
+
+static ssize_t set_direction_show(struct device *dev,
+				  struct device_attribute *attr,
+				  char *buf)
+{
+	struct most_channel *c = to_channel(dev);
+
+	if (c->cfg.direction & MOST_CH_TX)
+		return snprintf(buf, PAGE_SIZE, "tx\n");
+	else if (c->cfg.direction & MOST_CH_RX)
+		return snprintf(buf, PAGE_SIZE, "rx\n");
+	return snprintf(buf, PAGE_SIZE, "unconfigured\n");
+}
+
+static ssize_t set_datatype_show(struct device *dev,
+				 struct device_attribute *attr,
+				 char *buf)
+{
+	int i;
+	struct most_channel *c = to_channel(dev);
+
+	for (i = 0; i < ARRAY_SIZE(ch_data_type); i++) {
+		if (c->cfg.data_type & ch_data_type[i].most_ch_data_type)
+			return snprintf(buf, PAGE_SIZE, "%s",
+					ch_data_type[i].name);
+	}
+	return snprintf(buf, PAGE_SIZE, "unconfigured\n");
+}
+
+static ssize_t set_subbuffer_size_show(struct device *dev,
+				       struct device_attribute *attr,
+				       char *buf)
+{
+	struct most_channel *c = to_channel(dev);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", c->cfg.subbuffer_size);
+}
+
+static ssize_t set_packets_per_xact_show(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	struct most_channel *c = to_channel(dev);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", c->cfg.packets_per_xact);
+}
+
+static ssize_t set_dbr_size_show(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	struct most_channel *c = to_channel(dev);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", c->cfg.dbr_size);
+}
+
+#define to_dev_attr(a) container_of(a, struct device_attribute, attr)
+static umode_t channel_attr_is_visible(struct kobject *kobj,
+				       struct attribute *attr, int index)
+{
+	struct device_attribute *dev_attr = to_dev_attr(attr);
+	struct device *dev = kobj_to_dev(kobj);
+	struct most_channel *c = to_channel(dev);
+
+	if (!strcmp(dev_attr->attr.name, "set_dbr_size") &&
+	    (c->iface->interface != ITYPE_MEDIALB_DIM2))
+		return 0;
+	if (!strcmp(dev_attr->attr.name, "set_packets_per_xact") &&
+	    (c->iface->interface != ITYPE_USB))
+		return 0;
+
+	return attr->mode;
+}
+
+#define DEV_ATTR(_name)  (