[PATCH] USB: usbnet (7/9) module for CDC Ethernet

Makes the CDC Ethernet support live in a separate driver module.
This module is a bit special since it exports utility functions
that are reused by the the Zaurus and RNDIS drivers, but it's
not "core" like usbnet itself.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 509 insertions, 0 deletions

diff --git a/drivers/usb/net/cdc_ether.c b/drivers/usb/net/cdc_ether.c
new file mode 100644
index 000000000000..652b04bbf6af
--- /dev/null
+++ b/drivers/usb/net/cdc_ether.c
@@ -0,0 +1,509 @@
+/*
+ * CDC Ethernet based networking peripherals
+ * Copyright (C) 2003-2005 by David Brownell
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+// #define      DEBUG                   // error path messages, extra info
+// #define      VERBOSE                 // more; success messages
+
+#include <linux/config.h>
+#ifdef  CONFIG_USB_DEBUG
+#   define DEBUG
+#endif
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/ctype.h>
+#include <linux/ethtool.h>
+#include <linux/workqueue.h>
+#include <linux/mii.h>
+#include <linux/usb.h>
+#include <linux/usb_cdc.h>
+
+#include "usbnet.h"
+
+
+/*
+ * probes control interface, claims data interface, collects the bulk
+ * endpoints, activates data interface (if needed), maybe sets MTU.
+ * all pure cdc, except for certain firmware workarounds, and knowing
+ * that rndis uses one different rule.
+ */
+int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf)
+{
+        u8                              *buf = intf->cur_altsetting->extra;
+        int                             len = intf->cur_altsetting->extralen;
+        struct usb_interface_descriptor *d;
+        struct cdc_state                *info = (void *) &dev->data;
+        int                             status;
+        int                             rndis;
+        struct usb_driver               *driver = driver_of(intf);
+
+        if (sizeof dev->data < sizeof *info)
+                return -EDOM;
+
+        /* expect strict spec conformance for the descriptors, but
+         * cope with firmware which stores them in the wrong place
+         */
+        if (len == 0 && dev->udev->actconfig->extralen) {
+                /* Motorola SB4100 (and others: Brad Hards says it's
+                 * from a Broadcom design) put CDC descriptors here
+                 */
+                buf = dev->udev->actconfig->extra;
+                len = dev->udev->actconfig->extralen;
+                if (len)
+                        dev_dbg(&intf->dev,
+                                "CDC descriptors on config\n");
+        }
+
+        /* this assumes that if there's a non-RNDIS vendor variant
+         * of cdc-acm, it'll fail RNDIS requests cleanly.
+         */
+        rndis = (intf->cur_altsetting->desc.bInterfaceProtocol == 0xff);
+
+        memset(info, 0, sizeof *info);
+        info->control = intf;
+        while (len > 3) {
+                if (buf [1] != USB_DT_CS_INTERFACE)
+                        goto next_desc;
+
+                /* use bDescriptorSubType to identify the CDC descriptors.
+                 * We expect devices with CDC header and union descriptors.
+                 * For CDC Ethernet we need the ethernet descriptor.
+                 * For RNDIS, ignore two (pointless) CDC modem descriptors
+                 * in favor of a complicated OID-based RPC scheme doing what
+                 * CDC Ethernet achieves with a simple descriptor.
+                 */
+                switch (buf [2]) {
+                case USB_CDC_HEADER_TYPE:
+                        if (info->header) {
+                                dev_dbg(&intf->dev, "extra CDC header\n");
+                                goto bad_desc;
+                        }
+                        info->header = (void *) buf;
+                        if (info->header->bLength != sizeof *info->header) {
+                                dev_dbg(&intf->dev, "CDC header len %u\n",
+                                        info->header->bLength);
+                                goto bad_desc;
+                        }
+                        break;
+                case USB_CDC_UNION_TYPE:
+                        if (info->u) {
+                                dev_dbg(&intf->dev, "extra CDC union\n");
+                                goto bad_desc;
+                        }
+                        info->u = (void *) buf;
+                        if (info->u->bLength != sizeof *info->u) {
+                                dev_dbg(&intf->dev, "CDC union len %u\n",
+                                        info->u->bLength);
+                                goto bad_desc;
+                        }
+
+                        /* we need a master/control interface (what we're
+                         * probed with) and a slave/data interface; union
+                         * descriptors sort this all out.
+                         */
+                        info->control = usb_ifnum_to_if(dev->udev,
+                                                info->u->bMasterInterface0);
+                        info->data = usb_ifnum_to_if(dev->udev,
+                                                info->u->bSlaveInterface0);
+                        if (!info->control || !info->data) {
+                                dev_dbg(&intf->dev,
+                                        "master #%u/%p slave #%u/%p\n",
+                                        info->u->bMasterInterface0,
+                                        info->control,
+                                        info->u->bSlaveInterface0,
+                                        info->data);
+                                goto bad_desc;
+                        }
+                        if (info->control != intf) {
+                                dev_dbg(&intf->dev, "bogus CDC Union\n");
+                                /* Ambit USB Cable Modem (and maybe others)
+                                 * interchanges master and slave interface.
+                                 */
+                                if (info->data == intf) {
+                                        info->data = info->control;
+                                        info->control = intf;
+                                } else
+                                        goto bad_desc;
+                        }
+
+                        /* a data interface altsetting does the real i/o */
+                        d = &info->data->cur_altsetting->desc;
+                        if (d->bInterfaceClass != USB_CLASS_CDC_DATA) {
+                                dev_dbg(&intf->dev, "slave class %u\n",
+                                        d->bInterfaceClass);
+                                goto bad_desc;
+                        }
+                        break;
+                case USB_CDC_ETHERNET_TYPE:
+                        if (info->ether) {
+                                dev_dbg(&intf->dev, "extra CDC ether\n");
+                                goto bad_desc;
+                        }
+                        info->ether = (void *) buf;
+                        if (info->ether->bLength != sizeof *info->ether) {
+                                dev_dbg(&intf->dev, "CDC ether len %u\n",
+                                        info->ether->bLength);
+                                goto bad_desc;
+                        }
+                        dev->hard_mtu = le16_to_cpu(
+                                                info->ether->wMaxSegmentSize);
+                        /* because of Zaurus, we may be ignoring the host
+                         * side link address we were given.
+                         */
+                        break;
+                }
+next_desc:
+                len -= buf [0]; /* bLength */
+                buf += buf [0];
+        }
+
+        if (!info->header || !info->u || (!rndis && !info->ether)) {
+                dev_dbg(&intf->dev, "missing cdc %s%s%sdescriptor\n",
+                        info->header ? "" : "header ",
+                        info->u ? "" : "union ",
+                        info->ether ? "" : "ether ");
+                goto bad_desc;
+        }
+
+        /* claim data interface and set it up ... with side effects.
+         * network traffic can't flow until an altsetting is enabled.
+         */
+        status = usb_driver_claim_interface(driver, info->data, dev);
+        if (status < 0)
+                return status;
+        status = usbnet_get_endpoints(dev, info->data);
+        if (status < 0) {
+                /* ensure immediate exit from usbnet_disconnect */
+                usb_set_intfdata(info->data, NULL);
+                usb_driver_release_interface(driver, info->data);
+                return status;
+        }
+
+        /* status endpoint: optional for CDC Ethernet, not RNDIS (or ACM) */
+        dev->status = NULL;
+        if (info->control->cur_altsetting->desc.bNumEndpoints == 1) {
+                struct usb_endpoint_descriptor  *desc;
+
+                dev->status = &info->control->cur_altsetting->endpoint [0];
+                desc = &dev->status->desc;
+                if (desc->bmAttributes != USB_ENDPOINT_XFER_INT
+                                || !(desc->bEndpointAddress & USB_DIR_IN)
+                                || (le16_to_cpu(desc->wMaxPacketSize)
+                                        < sizeof(struct usb_cdc_notification))
+                                || !desc->bInterval) {
+                        dev_dbg(&intf->dev, "bad notification endpoint\n");
+                        dev->status = NULL;
+                }
+        }
+        if (rndis && !dev->status) {
+                dev_dbg(&intf->dev, "missing RNDIS status endpoint\n");
+                usb_set_intfdata(info->data, NULL);
+                usb_driver_release_interface(driver, info->data);
+                return -ENODEV;
+        }
+        return 0;
+
+bad_desc:
+        dev_info(&dev->udev->dev, "bad CDC descriptors\n");
+        return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(usbnet_generic_cdc_bind);
+
+void usbnet_cdc_unbind(struct usbnet *dev, struct usb_interface *intf)
+{
+        struct cdc_state                *info = (void *) &dev->data;
+        struct usb_driver               *driver = driver_of(intf);
+
+        /* disconnect master --> disconnect slave */
+        if (intf == info->control && info->data) {
+                /* ensure immediate exit from usbnet_disconnect */
+                usb_set_intfdata(info->data, NULL);
+                usb_driver_release_interface(driver, info->data);
+                info->data = NULL;
+        }
+
+        /* and vice versa (just in case) */
+        else if (intf == info->data && info->control) {
+                /* ensure immediate exit from usbnet_disconnect */
+                usb_set_intfdata(info->control, NULL);
+                usb_driver_release_interface(driver, info->control);
+                info->control = NULL;
+        }
+}
+EXPORT_SYMBOL_GPL(usbnet_cdc_unbind);
+
+
+/*-------------------------------------------------------------------------
+ *
+ * Communications Device Class, Ethernet Control model
+ *
+ * Takes two interfaces.  The DATA interface is inactive till an altsetting
+ * is selected.  Configuration data includes class descriptors.  There's
+ * an optional status endpoint on the control interface.
+ *
+ * This should interop with whatever the 2.4 "CDCEther.c" driver
+ * (by Brad Hards) talked with, with more functionality.
+ *
+ *-------------------------------------------------------------------------*/
+
+static void dumpspeed(struct usbnet *dev, __le32 *speeds)
+{
+        if (netif_msg_timer(dev))
+                devinfo(dev, "link speeds: %u kbps up, %u kbps down",
+                        __le32_to_cpu(speeds[0]) / 1000,
+                __le32_to_cpu(speeds[1]) / 1000);
+}
+
+static void cdc_status(struct usbnet *dev, struct urb *urb)
+{
+        struct usb_cdc_notification     *event;
+
+        if (urb->actual_length < sizeof *event)
+                return;
+
+        /* SPEED_CHANGE can get split into two 8-byte packets */
+        if (test_and_clear_bit(EVENT_STS_SPLIT, &dev->flags)) {
+                dumpspeed(dev, (__le32 *) urb->transfer_buffer);
+                return;
+        }
+
+        event = urb->transfer_buffer;
+        switch (event->bNotificationType) {
+        case USB_CDC_NOTIFY_NETWORK_CONNECTION:
+                if (netif_msg_timer(dev))
+                        devdbg(dev, "CDC: carrier %s",
+                                        event->wValue ? "on" : "off");
+                if (event->wValue)
+                        netif_carrier_on(dev->net);
+                else
+                        netif_carrier_off(dev->net);
+                break;
+        case USB_CDC_NOTIFY_SPEED_CHANGE:       /* tx/rx rates */
+                if (netif_msg_timer(dev))
+                        devdbg(dev, "CDC: speed change (len %d)",
+                                        urb->actual_length);
+                if (urb->actual_length != (sizeof *event + 8))
+                        set_bit(EVENT_STS_SPLIT, &dev->flags);
+                else
+                        dumpspeed(dev, (__le32 *) &event[1]);
+                break;
+        /* USB_CDC_NOTIFY_RESPONSE_AVAILABLE can happen too (e.g. RNDIS),
+         * but there are no standard formats for the response data.
+         */
+        default:
+                deverr(dev, "CDC: unexpected notification %02x!",
+                                 event->bNotificationType);
+                break;
+        }
+}
+
+static u8 nibble(unsigned char c)
+{
+        if (likely(isdigit(c)))
+                return c - '0';
+        c = toupper(c);
+        if (likely(isxdigit(c)))
+                return 10 + c - 'A';
+        return 0;
+}
+
+static inline int
+get_ethernet_addr(struct usbnet *dev, struct usb_cdc_ether_desc *e)
+{
+        int             tmp, i;
+        unsigned char   buf [13];
+
+        tmp = usb_string(dev->udev, e->iMACAddress, buf, sizeof buf);
+        if (tmp != 12) {
+                dev_dbg(&dev->udev->dev,
+                        "bad MAC string %d fetch, %d\n", e->iMACAddress, tmp);
+                if (tmp >= 0)
+                        tmp = -EINVAL;
+                return tmp;
+        }
+        for (i = tmp = 0; i < 6; i++, tmp += 2)
+                dev->net->dev_addr [i] =
+                        (nibble(buf [tmp]) << 4) + nibble(buf [tmp + 1]);
+        return 0;
+}
+
+static int cdc_bind(struct usbnet *dev, struct usb_interface *intf)
+{
+        int                             status;
+        struct cdc_state                *info = (void *) &dev->data;
+
+        status = usbnet_generic_cdc_bind(dev, intf);
+        if (status < 0)
+                return status;
+
+        status = get_ethernet_addr(dev, info->ether);
+        if (status < 0) {
+                usb_set_intfdata(info->data, NULL);
+                usb_driver_release_interface(driver_of(intf), info->data);
+                return status;
+        }
+
+        /* FIXME cdc-ether has some multicast code too, though it complains
+         * in routine cases.  info->ether describes the multicast support.
+         * Implement that here, manipulating the cdc filter as needed.
+         */
+        return 0;
+}
+
+static const struct driver_info cdc_info = {
+        .description =  "CDC Ethernet Device",
+        .flags =        FLAG_ETHER,
+        // .check_connect = cdc_check_connect,
+        .bind =         cdc_bind,
+        .unbind =       usbnet_cdc_unbind,
+        .status =       cdc_status,
+};
+
+/*-------------------------------------------------------------------------*/
+
+
+static const struct usb_device_id       products [] = {
+/*
+ * BLACKLIST !!
+ *
+ * First blacklist any products that are egregiously nonconformant
+ * with the CDC Ethernet specs.  Minor braindamage we cope with; when
+ * they're not even trying, needing a separate driver is only the first
+ * of the differences to show up.
+ */
+
+#define ZAURUS_MASTER_INTERFACE \
+        .bInterfaceClass        = USB_CLASS_COMM, \
+        .bInterfaceSubClass     = USB_CDC_SUBCLASS_ETHERNET, \
+        .bInterfaceProtocol     = USB_CDC_PROTO_NONE
+
+/* SA-1100 based Sharp Zaurus ("collie"), or compatible;
+ * wire-incompatible with true CDC Ethernet implementations.
+ * (And, it seems, needlessly so...)
+ */
+{
+        .match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
+                          | USB_DEVICE_ID_MATCH_DEVICE,
+        .idVendor               = 0x04DD,
+        .idProduct              = 0x8004,
+        ZAURUS_MASTER_INTERFACE,
+        .driver_info            = 0,
+},
+
+/* PXA-25x based Sharp Zaurii.  Note that it seems some of these
+ * (later models especially) may have shipped only with firmware
+ * advertising false "CDC MDLM" compatibility ... but we're not
+ * clear which models did that, so for now let's assume the worst.
+ */
+{
+        .match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
+                          | USB_DEVICE_ID_MATCH_DEVICE,
+        .idVendor               = 0x04DD,
+        .idProduct              = 0x8005,       /* A-300 */
+        ZAURUS_MASTER_INTERFACE,
+        .driver_info            = 0,
+}, {
+        .match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
+                          | USB_DEVICE_ID_MATCH_DEVICE,
+        .idVendor               = 0x04DD,
+        .idProduct              = 0x8006,       /* B-500/SL-5600 */
+        ZAURUS_MASTER_INTERFACE,
+        .driver_info            = 0,
+}, {
+        .match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
+                  | USB_DEVICE_ID_MATCH_DEVICE,
+        .idVendor               = 0x04DD,
+        .idProduct              = 0x8007,       /* C-700 */
+        ZAURUS_MASTER_INTERFACE,
+        .driver_info            = 0,
+}, {
+        .match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
+                 | USB_DEVICE_ID_MATCH_DEVICE,
+        .idVendor               = 0x04DD,
+        .idProduct              = 0x9031,       /* C-750 C-760 */
+        ZAURUS_MASTER_INTERFACE,
+        .driver_info            = 0,
+}, {
+        .match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
+                 | USB_DEVICE_ID_MATCH_DEVICE,
+        .idVendor               = 0x04DD,
+        .idProduct              = 0x9032,       /* SL-6000 */
+        ZAURUS_MASTER_INTERFACE,
+        .driver_info            = 0,
+}, {
+        .match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
+                 | USB_DEVICE_ID_MATCH_DEVICE,
+        .idVendor               = 0x04DD,
+        /* reported with some C860 units */
+        .idProduct              = 0x9050,       /* C-860 */
+        ZAURUS_MASTER_INTERFACE,
+        .driver_info            = 0,
+},
+
+/*
+ * WHITELIST!!!
+ *
+ * CDC Ether uses two interfaces, not necessarily consecutive.
+ * We match the main interface, ignoring the optional device
+ * class so we could handle devices that aren't exclusively
+ * CDC ether.
+ *
+ * NOTE:  this match must come AFTER entries blacklisting devices
+ * because of bugs/quirks in a given product (like Zaurus, above).
+ */
+{
+        USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ETHERNET,
+                        USB_CDC_PROTO_NONE),
+        .driver_info = (unsigned long) &cdc_info,
+},
+        { },            // END
+};
+MODULE_DEVICE_TABLE(usb, products);
+
+static struct usb_driver cdc_driver = {
+        .owner =        THIS_MODULE,
+        .name =         "cdc_ether",
+        .id_table =     products,
+        .probe =        usbnet_probe,
+        .disconnect =   usbnet_disconnect,
+        .suspend =      usbnet_suspend,
+        .resume =       usbnet_resume,
+};
+
+
+static int __init cdc_init(void)
+{
+        BUG_ON((sizeof(((struct usbnet *)0)->data)
+                        < sizeof(struct cdc_state)));
+
+        return usb_register(&cdc_driver);
+}
+module_init(cdc_init);
+
+static void __exit cdc_exit(void)
+{
+        usb_deregister(&cdc_driver);
+}
+module_exit(cdc_exit);
+
+MODULE_AUTHOR("David Brownell");
+MODULE_DESCRIPTION("USB CDC Ethernet devices");
+MODULE_LICENSE("GPL");