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path: root/drivers/usb/gadget/function/f_ecm.c
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Diffstat (limited to 'drivers/usb/gadget/function/f_ecm.c')
-rw-r--r--drivers/usb/gadget/function/f_ecm.c965
1 files changed, 965 insertions, 0 deletions
diff --git a/drivers/usb/gadget/function/f_ecm.c b/drivers/usb/gadget/function/f_ecm.c
new file mode 100644
index 000000000..ffe2486fc
--- /dev/null
+++ b/drivers/usb/gadget/function/f_ecm.c
@@ -0,0 +1,965 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * f_ecm.c -- USB CDC Ethernet (ECM) link function driver
+ *
+ * Copyright (C) 2003-2005,2008 David Brownell
+ * Copyright (C) 2008 Nokia Corporation
+ */
+
+/* #define VERBOSE_DEBUG */
+
+#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_ecm.h"
+
+
+/*
+ * This function is a "CDC Ethernet Networking Control Model" (CDC ECM)
+ * Ethernet link. The data transfer model is simple (packets sent and
+ * received over bulk endpoints using normal short packet termination),
+ * and the control model exposes various data and optional notifications.
+ *
+ * ECM is well standardized and (except for Microsoft) supported by most
+ * operating systems with USB host support. It's the preferred interop
+ * solution for Ethernet over USB, at least for firmware based solutions.
+ * (Hardware solutions tend to be more minimalist.) A newer and simpler
+ * "Ethernet Emulation Model" (CDC EEM) hasn't yet caught on.
+ *
+ * Note that ECM requires the use of "alternate settings" for its data
+ * interface. This means that the set_alt() method has real work to do,
+ * and also means that a get_alt() method is required.
+ */
+
+
+enum ecm_notify_state {
+ ECM_NOTIFY_NONE, /* don't notify */
+ ECM_NOTIFY_CONNECT, /* issue CONNECT next */
+ ECM_NOTIFY_SPEED, /* issue SPEED_CHANGE next */
+};
+
+struct f_ecm {
+ struct gether port;
+ u8 ctrl_id, data_id;
+
+ char ethaddr[14];
+
+ struct usb_ep *notify;
+ struct usb_request *notify_req;
+ u8 notify_state;
+ atomic_t notify_count;
+ bool is_open;
+
+ /* FIXME is_open needs some irq-ish locking
+ * ... possibly the same as port.ioport
+ */
+};
+
+static inline struct f_ecm *func_to_ecm(struct usb_function *f)
+{
+ return container_of(f, struct f_ecm, port.func);
+}
+
+/* peak (theoretical) bulk transfer rate in bits-per-second */
+static inline unsigned ecm_bitrate(struct usb_gadget *g)
+{
+ if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
+ return 13 * 1024 * 8 * 1000 * 8;
+ else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
+ return 13 * 512 * 8 * 1000 * 8;
+ else
+ return 19 * 64 * 1 * 1000 * 8;
+}
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * Include the status endpoint if we can, even though it's optional.
+ *
+ * Use wMaxPacketSize big enough to fit CDC_NOTIFY_SPEED_CHANGE in one
+ * packet, to simplify cancellation; and a big transfer interval, to
+ * waste less bandwidth.
+ *
+ * Some drivers (like Linux 2.4 cdc-ether!) "need" it to exist even
+ * if they ignore the connect/disconnect notifications that real aether
+ * can provide. More advanced cdc configurations might want to support
+ * encapsulated commands (vendor-specific, using control-OUT).
+ */
+
+#define ECM_STATUS_INTERVAL_MS 32
+#define ECM_STATUS_BYTECOUNT 16 /* 8 byte header + data */
+
+
+/* interface descriptor: */
+
+static struct usb_interface_assoc_descriptor
+ecm_iad_descriptor = {
+ .bLength = sizeof ecm_iad_descriptor,
+ .bDescriptorType = USB_DT_INTERFACE_ASSOCIATION,
+
+ /* .bFirstInterface = DYNAMIC, */
+ .bInterfaceCount = 2, /* control + data */
+ .bFunctionClass = USB_CLASS_COMM,
+ .bFunctionSubClass = USB_CDC_SUBCLASS_ETHERNET,
+ .bFunctionProtocol = USB_CDC_PROTO_NONE,
+ /* .iFunction = DYNAMIC */
+};
+
+
+static struct usb_interface_descriptor ecm_control_intf = {
+ .bLength = sizeof ecm_control_intf,
+ .bDescriptorType = USB_DT_INTERFACE,
+
+ /* .bInterfaceNumber = DYNAMIC */
+ /* status endpoint is optional; this could be patched later */
+ .bNumEndpoints = 1,
+ .bInterfaceClass = USB_CLASS_COMM,
+ .bInterfaceSubClass = USB_CDC_SUBCLASS_ETHERNET,
+ .bInterfaceProtocol = USB_CDC_PROTO_NONE,
+ /* .iInterface = DYNAMIC */
+};
+
+static struct usb_cdc_header_desc ecm_header_desc = {
+ .bLength = sizeof ecm_header_desc,
+ .bDescriptorType = USB_DT_CS_INTERFACE,
+ .bDescriptorSubType = USB_CDC_HEADER_TYPE,
+
+ .bcdCDC = cpu_to_le16(0x0110),
+};
+
+static struct usb_cdc_union_desc ecm_union_desc = {
+ .bLength = sizeof(ecm_union_desc),
+ .bDescriptorType = USB_DT_CS_INTERFACE,
+ .bDescriptorSubType = USB_CDC_UNION_TYPE,
+ /* .bMasterInterface0 = DYNAMIC */
+ /* .bSlaveInterface0 = DYNAMIC */
+};
+
+static struct usb_cdc_ether_desc ecm_desc = {
+ .bLength = sizeof ecm_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,
+};
+
+/* the default data interface has no endpoints ... */
+
+static struct usb_interface_descriptor ecm_data_nop_intf = {
+ .bLength = sizeof ecm_data_nop_intf,
+ .bDescriptorType = USB_DT_INTERFACE,
+
+ .bInterfaceNumber = 1,
+ .bAlternateSetting = 0,
+ .bNumEndpoints = 0,
+ .bInterfaceClass = USB_CLASS_CDC_DATA,
+ .bInterfaceSubClass = 0,
+ .bInterfaceProtocol = 0,
+ /* .iInterface = DYNAMIC */
+};
+
+/* ... but the "real" data interface has two bulk endpoints */
+
+static struct usb_interface_descriptor ecm_data_intf = {
+ .bLength = sizeof ecm_data_intf,
+ .bDescriptorType = USB_DT_INTERFACE,
+
+ .bInterfaceNumber = 1,
+ .bAlternateSetting = 1,
+ .bNumEndpoints = 2,
+ .bInterfaceClass = USB_CLASS_CDC_DATA,
+ .bInterfaceSubClass = 0,
+ .bInterfaceProtocol = 0,
+ /* .iInterface = DYNAMIC */
+};
+
+/* full speed support: */
+
+static struct usb_endpoint_descriptor fs_ecm_notify_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_IN,
+ .bmAttributes = USB_ENDPOINT_XFER_INT,
+ .wMaxPacketSize = cpu_to_le16(ECM_STATUS_BYTECOUNT),
+ .bInterval = ECM_STATUS_INTERVAL_MS,
+};
+
+static struct usb_endpoint_descriptor fs_ecm_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_ecm_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 *ecm_fs_function[] = {
+ /* CDC ECM control descriptors */
+ (struct usb_descriptor_header *) &ecm_iad_descriptor,
+ (struct usb_descriptor_header *) &ecm_control_intf,
+ (struct usb_descriptor_header *) &ecm_header_desc,
+ (struct usb_descriptor_header *) &ecm_union_desc,
+ (struct usb_descriptor_header *) &ecm_desc,
+
+ /* NOTE: status endpoint might need to be removed */
+ (struct usb_descriptor_header *) &fs_ecm_notify_desc,
+
+ /* data interface, altsettings 0 and 1 */
+ (struct usb_descriptor_header *) &ecm_data_nop_intf,
+ (struct usb_descriptor_header *) &ecm_data_intf,
+ (struct usb_descriptor_header *) &fs_ecm_in_desc,
+ (struct usb_descriptor_header *) &fs_ecm_out_desc,
+ NULL,
+};
+
+/* high speed support: */
+
+static struct usb_endpoint_descriptor hs_ecm_notify_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_IN,
+ .bmAttributes = USB_ENDPOINT_XFER_INT,
+ .wMaxPacketSize = cpu_to_le16(ECM_STATUS_BYTECOUNT),
+ .bInterval = USB_MS_TO_HS_INTERVAL(ECM_STATUS_INTERVAL_MS),
+};
+
+static struct usb_endpoint_descriptor hs_ecm_in_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_IN,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor hs_ecm_out_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_OUT,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = cpu_to_le16(512),
+};
+
+static struct usb_descriptor_header *ecm_hs_function[] = {
+ /* CDC ECM control descriptors */
+ (struct usb_descriptor_header *) &ecm_iad_descriptor,
+ (struct usb_descriptor_header *) &ecm_control_intf,
+ (struct usb_descriptor_header *) &ecm_header_desc,
+ (struct usb_descriptor_header *) &ecm_union_desc,
+ (struct usb_descriptor_header *) &ecm_desc,
+
+ /* NOTE: status endpoint might need to be removed */
+ (struct usb_descriptor_header *) &hs_ecm_notify_desc,
+
+ /* data interface, altsettings 0 and 1 */
+ (struct usb_descriptor_header *) &ecm_data_nop_intf,
+ (struct usb_descriptor_header *) &ecm_data_intf,
+ (struct usb_descriptor_header *) &hs_ecm_in_desc,
+ (struct usb_descriptor_header *) &hs_ecm_out_desc,
+ NULL,
+};
+
+/* super speed support: */
+
+static struct usb_endpoint_descriptor ss_ecm_notify_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_IN,
+ .bmAttributes = USB_ENDPOINT_XFER_INT,
+ .wMaxPacketSize = cpu_to_le16(ECM_STATUS_BYTECOUNT),
+ .bInterval = USB_MS_TO_HS_INTERVAL(ECM_STATUS_INTERVAL_MS),
+};
+
+static struct usb_ss_ep_comp_descriptor ss_ecm_intr_comp_desc = {
+ .bLength = sizeof ss_ecm_intr_comp_desc,
+ .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
+
+ /* the following 3 values can be tweaked if necessary */
+ /* .bMaxBurst = 0, */
+ /* .bmAttributes = 0, */
+ .wBytesPerInterval = cpu_to_le16(ECM_STATUS_BYTECOUNT),
+};
+
+static struct usb_endpoint_descriptor ss_ecm_in_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_IN,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = cpu_to_le16(1024),
+};
+
+static struct usb_endpoint_descriptor ss_ecm_out_desc = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_OUT,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = cpu_to_le16(1024),
+};
+
+static struct usb_ss_ep_comp_descriptor ss_ecm_bulk_comp_desc = {
+ .bLength = sizeof ss_ecm_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 *ecm_ss_function[] = {
+ /* CDC ECM control descriptors */
+ (struct usb_descriptor_header *) &ecm_iad_descriptor,
+ (struct usb_descriptor_header *) &ecm_control_intf,
+ (struct usb_descriptor_header *) &ecm_header_desc,
+ (struct usb_descriptor_header *) &ecm_union_desc,
+ (struct usb_descriptor_header *) &ecm_desc,
+
+ /* NOTE: status endpoint might need to be removed */
+ (struct usb_descriptor_header *) &ss_ecm_notify_desc,
+ (struct usb_descriptor_header *) &ss_ecm_intr_comp_desc,
+
+ /* data interface, altsettings 0 and 1 */
+ (struct usb_descriptor_header *) &ecm_data_nop_intf,
+ (struct usb_descriptor_header *) &ecm_data_intf,
+ (struct usb_descriptor_header *) &ss_ecm_in_desc,
+ (struct usb_descriptor_header *) &ss_ecm_bulk_comp_desc,
+ (struct usb_descriptor_header *) &ss_ecm_out_desc,
+ (struct usb_descriptor_header *) &ss_ecm_bulk_comp_desc,
+ NULL,
+};
+
+/* string descriptors: */
+
+static struct usb_string ecm_string_defs[] = {
+ [0].s = "CDC Ethernet Control Model (ECM)",
+ [1].s = "",
+ [2].s = "CDC Ethernet Data",
+ [3].s = "CDC ECM",
+ { } /* end of list */
+};
+
+static struct usb_gadget_strings ecm_string_table = {
+ .language = 0x0409, /* en-us */
+ .strings = ecm_string_defs,
+};
+
+static struct usb_gadget_strings *ecm_strings[] = {
+ &ecm_string_table,
+ NULL,
+};
+
+/*-------------------------------------------------------------------------*/
+
+static void ecm_do_notify(struct f_ecm *ecm)
+{
+ struct usb_request *req = ecm->notify_req;
+ struct usb_cdc_notification *event;
+ struct usb_composite_dev *cdev = ecm->port.func.config->cdev;
+ __le32 *data;
+ int status;
+
+ /* notification already in flight? */
+ if (atomic_read(&ecm->notify_count))
+ return;
+
+ event = req->buf;
+ switch (ecm->notify_state) {
+ case ECM_NOTIFY_NONE:
+ return;
+
+ case ECM_NOTIFY_CONNECT:
+ event->bNotificationType = USB_CDC_NOTIFY_NETWORK_CONNECTION;
+ if (ecm->is_open)
+ event->wValue = cpu_to_le16(1);
+ else
+ event->wValue = cpu_to_le16(0);
+ event->wLength = 0;
+ req->length = sizeof *event;
+
+ DBG(cdev, "notify connect %s\n",
+ ecm->is_open ? "true" : "false");
+ ecm->notify_state = ECM_NOTIFY_SPEED;
+ break;
+
+ case ECM_NOTIFY_SPEED:
+ event->bNotificationType = USB_CDC_NOTIFY_SPEED_CHANGE;
+ event->wValue = cpu_to_le16(0);
+ event->wLength = cpu_to_le16(8);
+ req->length = ECM_STATUS_BYTECOUNT;
+
+ /* SPEED_CHANGE data is up/down speeds in bits/sec */
+ data = req->buf + sizeof *event;
+ data[0] = cpu_to_le32(ecm_bitrate(cdev->gadget));
+ data[1] = data[0];
+
+ DBG(cdev, "notify speed %d\n", ecm_bitrate(cdev->gadget));
+ ecm->notify_state = ECM_NOTIFY_NONE;
+ break;
+ }
+ event->bmRequestType = 0xA1;
+ event->wIndex = cpu_to_le16(ecm->ctrl_id);
+
+ atomic_inc(&ecm->notify_count);
+ status = usb_ep_queue(ecm->notify, req, GFP_ATOMIC);
+ if (status < 0) {
+ atomic_dec(&ecm->notify_count);
+ DBG(cdev, "notify --> %d\n", status);
+ }
+}
+
+static void ecm_notify(struct f_ecm *ecm)
+{
+ /* NOTE on most versions of Linux, host side cdc-ethernet
+ * won't listen for notifications until its netdevice opens.
+ * The first notification then sits in the FIFO for a long
+ * time, and the second one is queued.
+ */
+ ecm->notify_state = ECM_NOTIFY_CONNECT;
+ ecm_do_notify(ecm);
+}
+
+static void ecm_notify_complete(struct usb_ep *ep, struct usb_request *req)
+{
+ struct f_ecm *ecm = req->context;
+ struct usb_composite_dev *cdev = ecm->port.func.config->cdev;
+ struct usb_cdc_notification *event = req->buf;
+
+ switch (req->status) {
+ case 0:
+ /* no fault */
+ atomic_dec(&ecm->notify_count);
+ break;
+ case -ECONNRESET:
+ case -ESHUTDOWN:
+ atomic_set(&ecm->notify_count, 0);
+ ecm->notify_state = ECM_NOTIFY_NONE;
+ break;
+ default:
+ DBG(cdev, "event %02x --> %d\n",
+ event->bNotificationType, req->status);
+ atomic_dec(&ecm->notify_count);
+ break;
+ }
+ ecm_do_notify(ecm);
+}
+
+static int ecm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
+{
+ struct f_ecm *ecm = func_to_ecm(f);
+ struct usb_composite_dev *cdev = f->config->cdev;
+ struct usb_request *req = cdev->req;
+ int value = -EOPNOTSUPP;
+ u16 w_index = le16_to_cpu(ctrl->wIndex);
+ u16 w_value = le16_to_cpu(ctrl->wValue);
+ u16 w_length = le16_to_cpu(ctrl->wLength);
+
+ /* composite driver infrastructure handles everything except
+ * CDC class messages; interface activation uses set_alt().
+ */
+ switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
+ case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
+ | USB_CDC_SET_ETHERNET_PACKET_FILTER:
+ /* see 6.2.30: no data, wIndex = interface,
+ * wValue = packet filter bitmap
+ */
+ if (w_length != 0 || w_index != ecm->ctrl_id)
+ goto invalid;
+ DBG(cdev, "packet filter %02x\n", w_value);
+ /* REVISIT locking of cdc_filter. This assumes the UDC
+ * driver won't have a concurrent packet TX irq running on
+ * another CPU; or that if it does, this write is atomic...
+ */
+ ecm->port.cdc_filter = w_value;
+ value = 0;
+ break;
+
+ /* and optionally:
+ * case USB_CDC_SEND_ENCAPSULATED_COMMAND:
+ * case USB_CDC_GET_ENCAPSULATED_RESPONSE:
+ * case USB_CDC_SET_ETHERNET_MULTICAST_FILTERS:
+ * case USB_CDC_SET_ETHERNET_PM_PATTERN_FILTER:
+ * case USB_CDC_GET_ETHERNET_PM_PATTERN_FILTER:
+ * case USB_CDC_GET_ETHERNET_STATISTIC:
+ */
+
+ default:
+invalid:
+ DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
+ ctrl->bRequestType, ctrl->bRequest,
+ w_value, w_index, w_length);
+ }
+
+ /* respond with data transfer or status phase? */
+ if (value >= 0) {
+ DBG(cdev, "ecm req%02x.%02x v%04x i%04x l%d\n",
+ ctrl->bRequestType, ctrl->bRequest,
+ w_value, w_index, w_length);
+ req->zero = 0;
+ req->length = value;
+ value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
+ if (value < 0)
+ ERROR(cdev, "ecm req %02x.%02x response err %d\n",
+ ctrl->bRequestType, ctrl->bRequest,
+ value);
+ }
+
+ /* device either stalls (value < 0) or reports success */
+ return value;
+}
+
+
+static int ecm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
+{
+ struct f_ecm *ecm = func_to_ecm(f);
+ struct usb_composite_dev *cdev = f->config->cdev;
+
+ /* Control interface has only altsetting 0 */
+ if (intf == ecm->ctrl_id) {
+ if (alt != 0)
+ goto fail;
+
+ VDBG(cdev, "reset ecm control %d\n", intf);
+ usb_ep_disable(ecm->notify);
+ if (!(ecm->notify->desc)) {
+ VDBG(cdev, "init ecm ctrl %d\n", intf);
+ if (config_ep_by_speed(cdev->gadget, f, ecm->notify))
+ goto fail;
+ }
+ usb_ep_enable(ecm->notify);
+
+ /* Data interface has two altsettings, 0 and 1 */
+ } else if (intf == ecm->data_id) {
+ if (alt > 1)
+ goto fail;
+
+ if (ecm->port.in_ep->enabled) {
+ DBG(cdev, "reset ecm\n");
+ gether_disconnect(&ecm->port);
+ }
+
+ if (!ecm->port.in_ep->desc ||
+ !ecm->port.out_ep->desc) {
+ DBG(cdev, "init ecm\n");
+ if (config_ep_by_speed(cdev->gadget, f,
+ ecm->port.in_ep) ||
+ config_ep_by_speed(cdev->gadget, f,
+ ecm->port.out_ep)) {
+ ecm->port.in_ep->desc = NULL;
+ ecm->port.out_ep->desc = NULL;
+ goto fail;
+ }
+ }
+
+ /* CDC Ethernet only sends data in non-default altsettings.
+ * Changing altsettings resets filters, statistics, etc.
+ */
+ if (alt == 1) {
+ struct net_device *net;
+
+ /* Enable zlps by default for ECM conformance;
+ * override for musb_hdrc (avoids txdma ovhead).
+ */
+ ecm->port.is_zlp_ok =
+ gadget_is_zlp_supported(cdev->gadget);
+ ecm->port.cdc_filter = DEFAULT_FILTER;
+ DBG(cdev, "activate ecm\n");
+ net = gether_connect(&ecm->port);
+ if (IS_ERR(net))
+ return PTR_ERR(net);
+ }
+
+ /* NOTE this can be a minor disagreement with the ECM spec,
+ * which says speed notifications will "always" follow
+ * connection notifications. But we allow one connect to
+ * follow another (if the first is in flight), and instead
+ * just guarantee that a speed notification is always sent.
+ */
+ ecm_notify(ecm);
+ } else
+ goto fail;
+
+ return 0;
+fail:
+ return -EINVAL;
+}
+
+/* Because the data interface supports multiple altsettings,
+ * this ECM function *MUST* implement a get_alt() method.
+ */
+static int ecm_get_alt(struct usb_function *f, unsigned intf)
+{
+ struct f_ecm *ecm = func_to_ecm(f);
+
+ if (intf == ecm->ctrl_id)
+ return 0;
+ return ecm->port.in_ep->enabled ? 1 : 0;
+}
+
+static void ecm_disable(struct usb_function *f)
+{
+ struct f_ecm *ecm = func_to_ecm(f);
+ struct usb_composite_dev *cdev = f->config->cdev;
+
+ DBG(cdev, "ecm deactivated\n");
+
+ if (ecm->port.in_ep->enabled) {
+ gether_disconnect(&ecm->port);
+ } else {
+ ecm->port.in_ep->desc = NULL;
+ ecm->port.out_ep->desc = NULL;
+ }
+
+ usb_ep_disable(ecm->notify);
+ ecm->notify->desc = NULL;
+}
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * Callbacks let us notify the host about connect/disconnect when the
+ * net device is opened or closed.
+ *
+ * For testing, note that link states on this side include both opened
+ * and closed variants of:
+ *
+ * - disconnected/unconfigured
+ * - configured but inactive (data alt 0)
+ * - configured and active (data alt 1)
+ *
+ * Each needs to be tested with unplug, rmmod, SET_CONFIGURATION, and
+ * SET_INTERFACE (altsetting). Remember also that "configured" doesn't
+ * imply the host is actually polling the notification endpoint, and
+ * likewise that "active" doesn't imply it's actually using the data
+ * endpoints for traffic.
+ */
+
+static void ecm_open(struct gether *geth)
+{
+ struct f_ecm *ecm = func_to_ecm(&geth->func);
+
+ DBG(ecm->port.func.config->cdev, "%s\n", __func__);
+
+ ecm->is_open = true;
+ ecm_notify(ecm);
+}
+
+static void ecm_close(struct gether *geth)
+{
+ struct f_ecm *ecm = func_to_ecm(&geth->func);
+
+ DBG(ecm->port.func.config->cdev, "%s\n", __func__);
+
+ ecm->is_open = false;
+ ecm_notify(ecm);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* ethernet function driver setup/binding */
+
+static int
+ecm_bind(struct usb_configuration *c, struct usb_function *f)
+{
+ struct usb_composite_dev *cdev = c->cdev;
+ struct f_ecm *ecm = func_to_ecm(f);
+ struct usb_string *us;
+ int status;
+ struct usb_ep *ep;
+
+ struct f_ecm_opts *ecm_opts;
+
+ if (!can_support_ecm(cdev->gadget))
+ return -EINVAL;
+
+ ecm_opts = container_of(f->fi, struct f_ecm_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 ecm_opts->bound access
+ */
+ if (!ecm_opts->bound) {
+ mutex_lock(&ecm_opts->lock);
+ gether_set_gadget(ecm_opts->net, cdev->gadget);
+ status = gether_register_netdev(ecm_opts->net);
+ mutex_unlock(&ecm_opts->lock);
+ if (status)
+ return status;
+ ecm_opts->bound = true;
+ }
+
+ ecm_string_defs[1].s = ecm->ethaddr;
+
+ us = usb_gstrings_attach(cdev, ecm_strings,
+ ARRAY_SIZE(ecm_string_defs));
+ if (IS_ERR(us))
+ return PTR_ERR(us);
+ ecm_control_intf.iInterface = us[0].id;
+ ecm_data_intf.iInterface = us[2].id;
+ ecm_desc.iMACAddress = us[1].id;
+ ecm_iad_descriptor.iFunction = us[3].id;
+
+ /* allocate instance-specific interface IDs */
+ status = usb_interface_id(c, f);
+ if (status < 0)
+ goto fail;
+ ecm->ctrl_id = status;
+ ecm_iad_descriptor.bFirstInterface = status;
+
+ ecm_control_intf.bInterfaceNumber = status;
+ ecm_union_desc.bMasterInterface0 = status;
+
+ status = usb_interface_id(c, f);
+ if (status < 0)
+ goto fail;
+ ecm->data_id = status;
+
+ ecm_data_nop_intf.bInterfaceNumber = status;
+ ecm_data_intf.bInterfaceNumber = status;
+ ecm_union_desc.bSlaveInterface0 = status;
+
+ status = -ENODEV;
+
+ /* allocate instance-specific endpoints */
+ ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_in_desc);
+ if (!ep)
+ goto fail;
+ ecm->port.in_ep = ep;
+
+ ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_out_desc);
+ if (!ep)
+ goto fail;
+ ecm->port.out_ep = ep;
+
+ /* NOTE: a status/notification endpoint is *OPTIONAL* but we
+ * don't treat it that way. It's simpler, and some newer CDC
+ * profiles (wireless handsets) no longer treat it as optional.
+ */
+ ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_notify_desc);
+ if (!ep)
+ goto fail;
+ ecm->notify = ep;
+
+ status = -ENOMEM;
+
+ /* allocate notification request and buffer */
+ ecm->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
+ if (!ecm->notify_req)
+ goto fail;
+ ecm->notify_req->buf = kmalloc(ECM_STATUS_BYTECOUNT, GFP_KERNEL);
+ if (!ecm->notify_req->buf)
+ goto fail;
+ ecm->notify_req->context = ecm;
+ ecm->notify_req->complete = ecm_notify_complete;
+
+ /* support all relevant hardware speeds... we expect that when
+ * hardware is dual speed, all bulk-capable endpoints work at
+ * both speeds
+ */
+ hs_ecm_in_desc.bEndpointAddress = fs_ecm_in_desc.bEndpointAddress;
+ hs_ecm_out_desc.bEndpointAddress = fs_ecm_out_desc.bEndpointAddress;
+ hs_ecm_notify_desc.bEndpointAddress =
+ fs_ecm_notify_desc.bEndpointAddress;
+
+ ss_ecm_in_desc.bEndpointAddress = fs_ecm_in_desc.bEndpointAddress;
+ ss_ecm_out_desc.bEndpointAddress = fs_ecm_out_desc.bEndpointAddress;
+ ss_ecm_notify_desc.bEndpointAddress =
+ fs_ecm_notify_desc.bEndpointAddress;
+
+ status = usb_assign_descriptors(f, ecm_fs_function, ecm_hs_function,
+ ecm_ss_function, ecm_ss_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().
+ */
+
+ ecm->port.open = ecm_open;
+ ecm->port.close = ecm_close;
+
+ DBG(cdev, "CDC Ethernet: %s speed IN/%s OUT/%s NOTIFY/%s\n",
+ gadget_is_superspeed(c->cdev->gadget) ? "super" :
+ gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
+ ecm->port.in_ep->name, ecm->port.out_ep->name,
+ ecm->notify->name);
+ return 0;
+
+fail:
+ if (ecm->notify_req) {
+ kfree(ecm->notify_req->buf);
+ usb_ep_free_request(ecm->notify, ecm->notify_req);
+ }
+
+ ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
+
+ return status;
+}
+
+static inline struct f_ecm_opts *to_f_ecm_opts(struct config_item *item)
+{
+ return container_of(to_config_group(item), struct f_ecm_opts,
+ func_inst.group);
+}
+
+/* f_ecm_item_ops */
+USB_ETHERNET_CONFIGFS_ITEM(ecm);
+
+/* f_ecm_opts_dev_addr */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(ecm);
+
+/* f_ecm_opts_host_addr */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(ecm);
+
+/* f_ecm_opts_qmult */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(ecm);
+
+/* f_ecm_opts_ifname */
+USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(ecm);
+
+static struct configfs_attribute *ecm_attrs[] = {
+ &ecm_opts_attr_dev_addr,
+ &ecm_opts_attr_host_addr,
+ &ecm_opts_attr_qmult,
+ &ecm_opts_attr_ifname,
+ NULL,
+};
+
+static const struct config_item_type ecm_func_type = {
+ .ct_item_ops = &ecm_item_ops,
+ .ct_attrs = ecm_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+static void ecm_free_inst(struct usb_function_instance *f)
+{
+ struct f_ecm_opts *opts;
+
+ opts = container_of(f, struct f_ecm_opts, func_inst);
+ if (opts->bound)
+ gether_cleanup(netdev_priv(opts->net));
+ else
+ free_netdev(opts->net);
+ kfree(opts);
+}
+
+static struct usb_function_instance *ecm_alloc_inst(void)
+{
+ struct f_ecm_opts *opts;
+
+ opts = kzalloc(sizeof(*opts), GFP_KERNEL);
+ if (!opts)
+ return ERR_PTR(-ENOMEM);
+ mutex_init(&opts->lock);
+ opts->func_inst.free_func_inst = ecm_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, "", &ecm_func_type);
+
+ return &opts->func_inst;
+}
+
+static void ecm_free(struct usb_function *f)
+{
+ struct f_ecm *ecm;
+ struct f_ecm_opts *opts;
+
+ ecm = func_to_ecm(f);
+ opts = container_of(f->fi, struct f_ecm_opts, func_inst);
+ kfree(ecm);
+ mutex_lock(&opts->lock);
+ opts->refcnt--;
+ mutex_unlock(&opts->lock);
+}
+
+static void ecm_unbind(struct usb_configuration *c, struct usb_function *f)
+{
+ struct f_ecm *ecm = func_to_ecm(f);
+
+ DBG(c->cdev, "ecm unbind\n");
+
+ usb_free_all_descriptors(f);
+
+ if (atomic_read(&ecm->notify_count)) {
+ usb_ep_dequeue(ecm->notify, ecm->notify_req);
+ atomic_set(&ecm->notify_count, 0);
+ }
+
+ kfree(ecm->notify_req->buf);
+ usb_ep_free_request(ecm->notify, ecm->notify_req);
+}
+
+static struct usb_function *ecm_alloc(struct usb_function_instance *fi)
+{
+ struct f_ecm *ecm;
+ struct f_ecm_opts *opts;
+ int status;
+
+ /* allocate and initialize one new instance */
+ ecm = kzalloc(sizeof(*ecm), GFP_KERNEL);
+ if (!ecm)
+ return ERR_PTR(-ENOMEM);
+
+ opts = container_of(fi, struct f_ecm_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, ecm->ethaddr,
+ sizeof(ecm->ethaddr));
+ if (status < 12) {
+ kfree(ecm);
+ mutex_unlock(&opts->lock);
+ return ERR_PTR(-EINVAL);
+ }
+
+ ecm->port.ioport = netdev_priv(opts->net);
+ mutex_unlock(&opts->lock);
+ ecm->port.cdc_filter = DEFAULT_FILTER;
+
+ ecm->port.func.name = "cdc_ethernet";
+ /* descriptors are per-instance copies */
+ ecm->port.func.bind = ecm_bind;
+ ecm->port.func.unbind = ecm_unbind;
+ ecm->port.func.set_alt = ecm_set_alt;
+ ecm->port.func.get_alt = ecm_get_alt;
+ ecm->port.func.setup = ecm_setup;
+ ecm->port.func.disable = ecm_disable;
+ ecm->port.func.free_func = ecm_free;
+
+ return &ecm->port.func;
+}
+
+DECLARE_USB_FUNCTION_INIT(ecm, ecm_alloc_inst, ecm_alloc);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David Brownell");