Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 506 insertions, 0 deletions

diff --git a/drivers/usb/gadget/function/f_subset.c b/drivers/usb/gadget/function/f_subset.c
new file mode 100644
index 000000000..51c1cae16
--- /dev/null
+++ b/drivers/usb/gadget/function/f_subset.c
@@ -0,0 +1,506 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * f_subset.c -- "CDC Subset" Ethernet link function driver
+ *
+ * Copyright (C) 2003-2005,2008 David Brownell
+ * Copyright (C) 2008 Nokia Corporation
+ */
+
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/etherdevice.h>
+
+#include "u_ether.h"
+#include "u_ether_configfs.h"
+#include "u_gether.h"
+
+/*
+ * This function packages a simple "CDC Subset" Ethernet port with no real
+ * control mechanisms; just raw data transfer over two bulk endpoints.
+ * The data transfer model is exactly that of CDC Ethernet, which is
+ * why we call it the "CDC Subset".
+ *
+ * Because it's not standardized, this has some interoperability issues.
+ * They mostly relate to driver binding, since the data transfer model is
+ * so simple (CDC Ethernet).  The original versions of this protocol used
+ * specific product/vendor IDs:  byteswapped IDs for Digital Equipment's
+ * SA-1100 "Itsy" board, which could run Linux 2.4 kernels and supported
+ * daughtercards with USB peripheral connectors.  (It was used more often
+ * with other boards, using the Itsy identifiers.)  Linux hosts recognized
+ * this with CONFIG_USB_ARMLINUX; these devices have only one configuration
+ * and one interface.
+ *
+ * At some point, MCCI defined a (nonconformant) CDC MDLM variant called
+ * "SAFE", which happens to have a mode which is identical to the "CDC
+ * Subset" in terms of data transfer and lack of control model.  This was
+ * adopted by later Sharp Zaurus models, and by some other software which
+ * Linux hosts recognize with CONFIG_USB_NET_ZAURUS.
+ *
+ * Because Microsoft's RNDIS drivers are far from robust, we added a few
+ * descriptors to the CDC Subset code, making this code look like a SAFE
+ * implementation.  This lets you use MCCI's host side MS-Windows drivers
+ * if you get fed up with RNDIS.  It also makes it easier for composite
+ * drivers to work, since they can use class based binding instead of
+ * caring about specific product and vendor IDs.
+ */
+
+struct f_gether {
+	struct gether			port;
+
+	char				ethaddr[14];
+};
+
+static inline struct f_gether *func_to_geth(struct usb_function *f)
+{
+	return container_of(f, struct f_gether, port.func);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * "Simple" CDC-subset option is a simple vendor-neutral model that most
+ * full speed controllers can handle:  one interface, two bulk endpoints.
+ * To assist host side drivers, we fancy it up a bit, and add descriptors so
+ * some host side drivers will understand it as a "SAFE" variant.
+ *
+ * "SAFE" loosely follows CDC WMC MDLM, violating the spec in various ways.
+ * Data endpoints live in the control interface, there's no data interface.
+ * And it's not used to talk to a cell phone radio.
+ */
+
+/* interface descriptor: */
+
+static struct usb_interface_descriptor subset_data_intf = {
+	.bLength =		sizeof subset_data_intf,
+	.bDescriptorType =	USB_DT_INTERFACE,
+
+	/* .bInterfaceNumber = DYNAMIC */
+	.bAlternateSetting =	0,
+	.bNumEndpoints =	2,
+	.bInterfaceClass =      USB_CLASS_COMM,
+	.bInterfaceSubClass =	USB_CDC_SUBCLASS_MDLM,
+	.bInterfaceProtocol =	0,
+	/* .iInterface = DYNAMIC */
+};
+
+static struct usb_cdc_header_desc mdlm_header_desc = {
+	.bLength =		sizeof mdlm_header_desc,
+	.bDescriptorType =	USB_DT_CS_INTERFACE,
+	.bDescriptorSubType =	USB_CDC_HEADER_TYPE,
+
+	.bcdCDC =		cpu_to_le16(0x0110),
+};
+
+static struct usb_cdc_mdlm_desc mdlm_desc = {
+	.bLength =		sizeof mdlm_desc,
+	.bDescriptorType =	USB_DT_CS_INTERFACE,
+	.bDescriptorSubType =	USB_CDC_MDLM_TYPE,
+
+	.bcdVersion =		cpu_to_le16(0x0100),
+	.bGUID = {
+		0x5d, 0x34, 0xcf, 0x66, 0x11, 0x18, 0x11, 0xd6,
+		0xa2, 0x1a, 0x00, 0x01, 0x02, 0xca, 0x9a, 0x7f,
+	},
+};
+
+/* since "usb_cdc_mdlm_detail_desc" is a variable length structure, we
+ * can't really use its struct.  All we do here is say that we're using
+ * the submode of "SAFE" which directly matches the CDC Subset.
+ */
+static u8 mdlm_detail_desc[] = {
+	6,
+	USB_DT_CS_INTERFACE,
+	USB_CDC_MDLM_DETAIL_TYPE,
+
+	0,	/* "SAFE" */
+	0,	/* network control capabilities (none) */
+	0,	/* network data capabilities ("raw" encapsulation) */
+};
+
+static struct usb_cdc_ether_desc ether_desc = {
+	.bLength =		sizeof ether_desc,
+	.bDescriptorType =	USB_DT_CS_INTERFACE,
+	.bDescriptorSubType =	USB_CDC_ETHERNET_TYPE,
+
+	/* this descriptor actually adds value, surprise! */
+	/* .iMACAddress = DYNAMIC */
+	.bmEthernetStatistics =	cpu_to_le32(0), /* no statistics */
+	.wMaxSegmentSize =	cpu_to_le16(ETH_FRAME_LEN),
+	.wNumberMCFilters =	cpu_to_le16(0),
+	.bNumberPowerFilters =	0,
+};
+
+/* full speed support: */
+
+static struct usb_endpoint_descriptor fs_subset_in_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	.bEndpointAddress =	USB_DIR_IN,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_endpoint_descriptor fs_subset_out_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	.bEndpointAddress =	USB_DIR_OUT,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_descriptor_header *fs_eth_function[] = {
+	(struct usb_descriptor_header *) &subset_data_intf,
+	(struct usb_descriptor_header *) &mdlm_header_desc,
+	(struct usb_descriptor_header *) &mdlm_desc,
+	(struct usb_descriptor_header *) &mdlm_detail_desc,
+	(struct usb_descriptor_header *) &ether_desc,
+	(struct usb_descriptor_header *) &fs_subset_in_desc,
+	(struct usb_descriptor_header *) &fs_subset_out_desc,
+	NULL,
+};
+
+/* high speed support: */
+
+static struct usb_endpoint_descriptor hs_subset_in_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor hs_subset_out_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(512),
+};
+
+static struct usb_descriptor_header *hs_eth_function[] = {
+	(struct usb_descriptor_header *) &subset_data_intf,
+	(struct usb_descriptor_header *) &mdlm_header_desc,
+	(struct usb_descriptor_header *) &mdlm_desc,
+	(struct usb_descriptor_header *) &mdlm_detail_desc,
+	(struct usb_descriptor_header *) &ether_desc,
+	(struct usb_descriptor_header *) &hs_subset_in_desc,
+	(struct usb_descriptor_header *) &hs_subset_out_desc,
+	NULL,
+};
+
+/* super speed support: */
+
+static struct usb_endpoint_descriptor ss_subset_in_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(1024),
+};
+
+static struct usb_endpoint_descriptor ss_subset_out_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	cpu_to_le16(1024),
+};
+
+static struct usb_ss_ep_comp_descriptor ss_subset_bulk_comp_desc = {
+	.bLength =		sizeof ss_subset_bulk_comp_desc,
+	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
+
+	/* the following 2 values can be tweaked if necessary */
+	/* .bMaxBurst =		0, */
+	/* .bmAttributes =	0, */
+};
+
+static struct usb_descriptor_header *ss_eth_function[] = {
+	(struct usb_descriptor_header *) &subset_data_intf,
+	(struct usb_descriptor_header *) &mdlm_header_desc,
+	(struct usb_descriptor_header *) &mdlm_desc,
+	(struct usb_descriptor_header *) &mdlm_detail_desc,
+	(struct usb_descriptor_header *) &ether_desc,
+	(struct usb_descriptor_header *) &ss_subset_in_desc,
+	(struct usb_descriptor_header *) &ss_subset_bulk_comp_desc,
+	(struct usb_descriptor_header *) &ss_subset_out_desc,
+	(struct usb_descriptor_header *) &ss_subset_bulk_comp_desc,
+	NULL,
+};
+
+/* string descriptors: */
+
+static struct usb_string geth_string_defs[] = {
+	[0].s = "CDC Ethernet Subset/SAFE",
+	[1].s = "",
+	{  } /* end of list */
+};
+
+static struct usb_gadget_strings geth_string_table = {
+	.language =		0x0409,	/* en-us */
+	.strings =		geth_string_defs,
+};
+
+static struct usb_gadget_strings *geth_strings[] = {
+	&geth_string_table,
+	NULL,
+};
+
+/*-------------------------------------------------------------------------*/
+
+static int geth_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
+{
+	struct f_gether		*geth = func_to_geth(f);
+	struct usb_composite_dev *cdev = f->config->cdev;
+	struct net_device	*net;
+
+	/* we know alt == 0, so this is an activation or a reset */
+
+	if (geth->port.in_ep->enabled) {
+		DBG(cdev, "reset cdc subset\n");
+		gether_disconnect(&geth->port);
+	}
+
+	DBG(cdev, "init + activate cdc subset\n");
+	if (config_ep_by_speed(cdev->gadget, f, geth->port.in_ep) ||
+	    config_ep_by_speed(cdev->gadget, f, geth->port.out_ep)) {
+		geth->port.in_ep->desc = NULL;
+		geth->port.out_ep->desc = NULL;
+		return -EINVAL;
+	}
+
+	net = gether_connect(&geth->port);
+	return PTR_ERR_OR_ZERO(net);
+}
+
+static void geth_disable(struct usb_function *f)
+{
+	struct f_gether	*geth = func_to_geth(f);
+	struct usb_composite_dev *cdev = f->config->cdev;
+
+	DBG(cdev, "net deactivated\n");
+	gether_disconnect(&geth->port);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* serial function driver setup/binding */
+
+static int
+geth_bind(struct usb_configuration *c, struct usb_function *f)
+{
+	struct usb_composite_dev *cdev = c->cdev;
+	struct f_gether		*geth = func_to_geth(f);
+	struct usb_string	*us;
+	int			status;
+	struct usb_ep		*ep;
+
+	struct f_gether_opts	*gether_opts;
+
+	gether_opts = container_of(f->fi, struct f_gether_opts, func_inst);
+
+	/*
+	 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
+	 * configurations are bound in sequence with list_for_each_entry,
+	 * in each configuration its functions are bound in sequence
+	 * with list_for_each_entry, so we assume no race condition
+	 * with regard to gether_opts->bound access
+	 */
+	if (!gether_opts->bound) {
+		mutex_lock(&gether_opts->lock);
+		gether_set_gadget(gether_opts->net, cdev->gadget);
+		status = gether_register_netdev(gether_opts->net);
+		mutex_unlock(&gether_opts->lock);
+		if (status)
+			return status;
+		gether_opts->bound = true;
+	}
+
+	us = usb_gstrings_attach(cdev, geth_strings,
+				 ARRAY_SIZE(geth_string_defs));
+	if (IS_ERR(us))
+		return PTR_ERR(us);
+
+	subset_data_intf.iInterface = us[0].id;
+	ether_desc.iMACAddress = us[1].id;
+
+	/* allocate instance-specific interface IDs */
+	status = usb_interface_id(c, f);
+	if (status < 0)
+		goto fail;
+	subset_data_intf.bInterfaceNumber = status;
+
+	status = -ENODEV;
+
+	/* allocate instance-specific endpoints */
+	ep = usb_ep_autoconfig(cdev->gadget, &fs_subset_in_desc);
+	if (!ep)
+		goto fail;
+	geth->port.in_ep = ep;
+
+	ep = usb_ep_autoconfig(cdev->gadget, &fs_subset_out_desc);
+	if (!ep)
+		goto fail;
+	geth->port.out_ep = ep;
+
+	/* support all relevant hardware speeds... we expect that when
+	 * hardware is dual speed, all bulk-capable endpoints work at
+	 * both speeds
+	 */
+	hs_subset_in_desc.bEndpointAddress = fs_subset_in_desc.bEndpointAddress;
+	hs_subset_out_desc.bEndpointAddress =
+		fs_subset_out_desc.bEndpointAddress;
+
+	ss_subset_in_desc.bEndpointAddress = fs_subset_in_desc.bEndpointAddress;
+	ss_subset_out_desc.bEndpointAddress =
+		fs_subset_out_desc.bEndpointAddress;
+
+	status = usb_assign_descriptors(f, fs_eth_function, hs_eth_function,
+			ss_eth_function, ss_eth_function);
+	if (status)
+		goto fail;
+
+	/* NOTE:  all that is done without knowing or caring about
+	 * the network link ... which is unavailable to this code
+	 * until we're activated via set_alt().
+	 */
+
+	DBG(cdev, "CDC Subset: %s speed IN/%s OUT/%s\n",
+			gadget_is_superspeed(c->cdev->gadget) ? "super" :
+			gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
+			geth->port.in_ep->name, geth->port.out_ep->name);
+	return 0;
+
+fail:
+	ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
+
+	return status;
+}
+
+static inline struct f_gether_opts *to_f_gether_opts(struct config_item *item)
+{
+	return container_of(to_config_group(item), struct f_gether_opts,
+			    func_inst.group);
+}
+
+/* f_gether_item_ops */
+USB_ETHERNET_CONFIGFS_ITEM(gether);
+
+/* f_gether_opts_dev_addr */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(gether);
+
+/* f_gether_opts_host_addr */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(gether);
+
+/* f_gether_opts_qmult */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(gether);
+
+/* f_gether_opts_ifname */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(gether);
+
+static struct configfs_attribute *gether_attrs[] = {
+	&gether_opts_attr_dev_addr,
+	&gether_opts_attr_host_addr,
+	&gether_opts_attr_qmult,
+	&gether_opts_attr_ifname,
+	NULL,
+};
+
+static const struct config_item_type gether_func_type = {
+	.ct_item_ops	= &gether_item_ops,
+	.ct_attrs	= gether_attrs,
+	.ct_owner	= THIS_MODULE,
+};
+
+static void geth_free_inst(struct usb_function_instance *f)
+{
+	struct f_gether_opts *opts;
+
+	opts = container_of(f, struct f_gether_opts, func_inst);
+	if (opts->bound)
+		gether_cleanup(netdev_priv(opts->net));
+	else
+		free_netdev(opts->net);
+	kfree(opts);
+}
+
+static struct usb_function_instance *geth_alloc_inst(void)
+{
+	struct f_gether_opts *opts;
+
+	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
+	if (!opts)
+		return ERR_PTR(-ENOMEM);
+	mutex_init(&opts->lock);
+	opts->func_inst.free_func_inst = geth_free_inst;
+	opts->net = gether_setup_default();
+	if (IS_ERR(opts->net)) {
+		struct net_device *net = opts->net;
+		kfree(opts);
+		return ERR_CAST(net);
+	}
+
+	config_group_init_type_name(&opts->func_inst.group, "",
+				    &gether_func_type);
+
+	return &opts->func_inst;
+}
+
+static void geth_free(struct usb_function *f)
+{
+	struct f_gether *eth;
+
+	eth = func_to_geth(f);
+	kfree(eth);
+}
+
+static void geth_unbind(struct usb_configuration *c, struct usb_function *f)
+{
+	geth_string_defs[0].id = 0;
+	usb_free_all_descriptors(f);
+}
+
+static struct usb_function *geth_alloc(struct usb_function_instance *fi)
+{
+	struct f_gether	*geth;
+	struct f_gether_opts *opts;
+	int status;
+
+	/* allocate and initialize one new instance */
+	geth = kzalloc(sizeof(*geth), GFP_KERNEL);
+	if (!geth)
+		return ERR_PTR(-ENOMEM);
+
+	opts = container_of(fi, struct f_gether_opts, func_inst);
+
+	mutex_lock(&opts->lock);
+	opts->refcnt++;
+	/* export host's Ethernet address in CDC format */
+	status = gether_get_host_addr_cdc(opts->net, geth->ethaddr,
+					  sizeof(geth->ethaddr));
+	if (status < 12) {
+		kfree(geth);
+		mutex_unlock(&opts->lock);
+		return ERR_PTR(-EINVAL);
+	}
+	geth_string_defs[1].s = geth->ethaddr;
+
+	geth->port.ioport = netdev_priv(opts->net);
+	mutex_unlock(&opts->lock);
+	geth->port.cdc_filter = DEFAULT_FILTER;
+
+	geth->port.func.name = "cdc_subset";
+	geth->port.func.bind = geth_bind;
+	geth->port.func.unbind = geth_unbind;
+	geth->port.func.set_alt = geth_set_alt;
+	geth->port.func.disable = geth_disable;
+	geth->port.func.free_func = geth_free;
+
+	return &geth->port.func;
+}
+
+DECLARE_USB_FUNCTION_INIT(geth, geth_alloc_inst, geth_alloc);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David Brownell");