[PATCH] USB: usbnet (9/9) module for pl2301/2302 cables

This wraps up the conversion of the "usbnet" driver structure, by
moving the Prolific PL-2201/2302 minidriver to a module of its own.
It also includes some minor cleanups to the remaining "usbnet" file,
notably removing that long changelog at the top.

Minor historical note:  Linux 2.2 first called the driver for
this hardware "plusb".

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

4 files changed, 179 insertions, 217 deletions

diff --git a/drivers/usb/net/Kconfig b/drivers/usb/net/Kconfig
index 5f3ae1e06b1e..8c010bb44eb8 100644
--- a/drivers/usb/net/Kconfig
+++ b/drivers/usb/net/Kconfig
@@ -99,7 +99,7 @@ config USB_USBNET
           with "minidrivers" built around a common network driver core
           that supports deep queues for efficient transfers.  (This gives
           better performance with small packets and at high speeds).
-          
+
           The USB host runs "usbnet", and the other end of the link might be:
 
           - Another USB host, when using USB "network" or "data transfer"
@@ -125,20 +125,6 @@ config USB_USBNET
           To compile this driver as a module, choose M here: the
           module will be called usbnet.
 
-comment "USB Host-to-Host Cables"
-        depends on USB_USBNET
-
-config USB_PL2301
-        boolean "Prolific PL-2301/2302 based cables"
-        default y
-        # handshake/init/reset problems, from original 'plusb' driver
-        depends on USB_USBNET && EXPERIMENTAL
-        help
-          Choose this option if you're using a host-to-host cable
-          with one of these chips.
-
-comment "Drivers built using the usbnet core"
-
 config USB_NET_AX8817X
         tristate "ASIX AX88xxx Based USB 2.0 Ethernet Adapters"
         depends on USB_USBNET && NET_ETHERNET
@@ -212,6 +198,15 @@ config USB_NET_NET1080
           on this design:  one NetChip 1080 chip and supporting logic,
           optionally with LEDs that indicate traffic
 
+config USB_NET_PLUSB
+        tristate "Prolific PL-2301/2302 based cables"
+        # if the handshake/init/reset problems, from original 'plusb',
+        # are ever resolved ... then remove "experimental"
+        depends on USB_USBNET && EXPERIMENTAL
+        help
+          Choose this option if you're using a host-to-host cable
+          with one of these chips.
+
 config USB_NET_RNDIS_HOST
         tristate "Host for RNDIS devices (EXPERIMENTAL)"
         depends on USB_USBNET && EXPERIMENTAL
diff --git a/drivers/usb/net/Makefile b/drivers/usb/net/Makefile
index cb789c3ded53..222c0495f791 100644
--- a/drivers/usb/net/Makefile
+++ b/drivers/usb/net/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_USB_NET_AX8817X)	+= asix.o
 obj-$(CONFIG_USB_NET_CDCETHER)  += cdc_ether.o
 obj-$(CONFIG_USB_NET_GL620A)    += gl620a.o
 obj-$(CONFIG_USB_NET_NET1080)   += net1080.o
+obj-$(CONFIG_USB_NET_PLUSB)     += plusb.o
 obj-$(CONFIG_USB_NET_RNDIS_HOST)        += rndis_host.o
 obj-$(CONFIG_USB_NET_CDC_SUBSET)        += cdc_subset.o
 obj-$(CONFIG_USB_NET_ZAURUS)    += zaurus.o
diff --git a/drivers/usb/net/plusb.c b/drivers/usb/net/plusb.c
new file mode 100644
index 000000000000..74c2b3581c76
--- /dev/null
+++ b/drivers/usb/net/plusb.c
@@ -0,0 +1,156 @@
+/*
+ * PL-2301/2302 USB host-to-host link cables
+ * Copyright (C) 2000-2005 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/ethtool.h>
+#include <linux/workqueue.h>
+#include <linux/mii.h>
+#include <linux/usb.h>
+
+#include "usbnet.h"
+
+
+/*
+ * Prolific PL-2301/PL-2302 driver ... http://www.prolifictech.com
+ *
+ * The protocol and handshaking used here should be bug-compatible
+ * with the Linux 2.2 "plusb" driver, by Deti Fliegl.
+ *
+ * HEADS UP:  this handshaking isn't all that robust.  This driver
+ * gets confused easily if you unplug one end of the cable then
+ * try to connect it again; you'll need to restart both ends. The
+ * "naplink" software (used by some PlayStation/2 deveopers) does
+ * the handshaking much better!   Also, sometimes this hardware
+ * seems to get wedged under load.  Prolific docs are weak, and
+ * don't identify differences between PL2301 and PL2302, much less
+ * anything to explain the different PL2302 versions observed.
+ */
+
+/*
+ * Bits 0-4 can be used for software handshaking; they're set from
+ * one end, cleared from the other, "read" with the interrupt byte.
+ */
+#define PL_S_EN         (1<<7)          /* (feature only) suspend enable */
+/* reserved bit -- rx ready (6) ? */
+#define PL_TX_READY     (1<<5)          /* (interrupt only) transmit ready */
+#define PL_RESET_OUT    (1<<4)          /* reset output pipe */
+#define PL_RESET_IN     (1<<3)          /* reset input pipe */
+#define PL_TX_C         (1<<2)          /* transmission complete */
+#define PL_TX_REQ       (1<<1)          /* transmission received */
+#define PL_PEER_E       (1<<0)          /* peer exists */
+
+static inline int
+pl_vendor_req(struct usbnet *dev, u8 req, u8 val, u8 index)
+{
+        return usb_control_msg(dev->udev,
+                usb_rcvctrlpipe(dev->udev, 0),
+                req,
+                USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
+                val, index,
+                NULL, 0,
+                USB_CTRL_GET_TIMEOUT);
+}
+
+static inline int
+pl_clear_QuickLink_features(struct usbnet *dev, int val)
+{
+        return pl_vendor_req(dev, 1, (u8) val, 0);
+}
+
+static inline int
+pl_set_QuickLink_features(struct usbnet *dev, int val)
+{
+        return pl_vendor_req(dev, 3, (u8) val, 0);
+}
+
+static int pl_reset(struct usbnet *dev)
+{
+        /* some units seem to need this reset, others reject it utterly.
+         * FIXME be more like "naplink" or windows drivers.
+         */
+        (void) pl_set_QuickLink_features(dev,
+                PL_S_EN|PL_RESET_OUT|PL_RESET_IN|PL_PEER_E);
+        return 0;
+}
+
+static const struct driver_info prolific_info = {
+        .description =  "Prolific PL-2301/PL-2302",
+        .flags =        FLAG_NO_SETINT,
+                /* some PL-2302 versions seem to fail usb_set_interface() */
+        .reset =        pl_reset,
+};
+
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * Proilific's name won't normally be on the cables, and
+ * may not be on the device.
+ */
+
+static const struct usb_device_id       products [] = {
+
+{
+        USB_DEVICE(0x067b, 0x0000),     // PL-2301
+        .driver_info =  (unsigned long) &prolific_info,
+}, {
+        USB_DEVICE(0x067b, 0x0001),     // PL-2302
+        .driver_info =  (unsigned long) &prolific_info,
+},
+
+        { },            // END
+};
+MODULE_DEVICE_TABLE(usb, products);
+
+static struct usb_driver plusb_driver = {
+        .owner =        THIS_MODULE,
+        .name =         "plusb",
+        .id_table =     products,
+        .probe =        usbnet_probe,
+        .disconnect =   usbnet_disconnect,
+        .suspend =      usbnet_suspend,
+        .resume =       usbnet_resume,
+};
+
+static int __init plusb_init(void)
+{
+        return usb_register(&plusb_driver);
+}
+module_init(plusb_init);
+
+static void __exit plusb_exit(void)
+{
+        usb_deregister(&plusb_driver);
+}
+module_exit(plusb_exit);
+
+MODULE_AUTHOR("David Brownell");
+MODULE_DESCRIPTION("Prolific PL-2301/2302 USB Host to Host Link Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/usb/net/usbnet.c b/drivers/usb/net/usbnet.c
index 6c78a42affaa..6c460918d54f 100644
--- a/drivers/usb/net/usbnet.c
+++ b/drivers/usb/net/usbnet.c
@@ -1,5 +1,5 @@
 /*
- * USB Networking Links
+ * USB Network driver infrastructure
  * Copyright (C) 2000-2005 by David Brownell
  * Copyright (C) 2003-2005 David Hollis <dhollis@davehollis.com>
  *
@@ -20,96 +20,15 @@
 
 /*
  * This is a generic "USB networking" framework that works with several
- * kinds of full and high speed networking devices:
+ * kinds of full and high speed networking devices:  host-to-host cables,
+ * smart usb peripherals, and actual Ethernet adapters.
  *
- *   + USB host-to-host "network cables", used for IP-over-USB links.
- *     These are often used for Laplink style connectivity products.
- *      - AnchorChip 2720
- *      - Belkin, eTEK (interops with Win32 drivers)
- *      - GeneSys GL620USB-A
- *      - NetChip 1080 (interoperates with NetChip Win32 drivers)
- *      - Prolific PL-2301/2302 (replaces "plusb" driver)
- *      - KC Technology KC2190
- *
- *   + Smart USB devices can support such links directly, using Internet
- *     standard protocols instead of proprietary host-to-device links.
- *      - Linux PDAs like iPaq, Yopy, and Zaurus
- *      - The BLOB boot loader (for diskless booting)
- *      - Linux "gadgets", perhaps using PXA-2xx or Net2280 controllers
- *      - Devices using EPSON's sample USB firmware
- *      - CDC-Ethernet class devices, such as many cable modems
- *
- *   + Adapters to networks such as Ethernet.
- *      - AX8817X based USB 2.0 products
- *
- * Links to these devices can be bridged using Linux Ethernet bridging.
- * With minor exceptions, these all use similar USB framing for network
- * traffic, but need different protocols for control traffic.
- *
- * USB devices can implement their side of this protocol at the cost
- * of two bulk endpoints; it's not restricted to "cable" applications.
- * See the SA1110, Zaurus, or EPSON device/client support in this driver;
- * slave/target drivers such as "usb-eth" (on most SA-1100 PDAs) or
- * "g_ether" (in the Linux "gadget" framework) implement that behavior
- * within devices.
- *
- *
- * CHANGELOG:
- *
- * 13-sep-2000  experimental, new
- * 10-oct-2000  usb_device_id table created. 
- * 28-oct-2000  misc fixes; mostly, discard more TTL-mangled rx packets.
- * 01-nov-2000  usb_device_id table and probing api update by
- *              Adam J. Richter <adam@yggdrasil.com>.
- * 18-dec-2000  (db) tx watchdog, "net1080" renaming to "usbnet", device_info
- *              and prolific support, isolate net1080-specific bits, cleanup.
- *              fix unlink_urbs oops in D3 PM resume code path.
- *
- * 02-feb-2001  (db) fix tx skb sharing, packet length, match_flags, ...
- * 08-feb-2001  stubbed in "linuxdev", maybe the SA-1100 folk can use it;
- *              AnchorChips 2720 support (from spec) for testing;
- *              fix bit-ordering problem with ethernet multicast addr
- * 19-feb-2001  Support for clearing halt conditions. SA1100 UDC support
- *              updates. Oleg Drokin (green@iXcelerator.com)
- * 25-mar-2001  More SA-1100 updates, including workaround for ip problem
- *              expecting cleared skb->cb and framing change to match latest
- *              handhelds.org version (Oleg).  Enable device IDs from the
- *              Win32 Belkin driver; other cleanups (db).
- * 16-jul-2001  Bugfixes for uhci oops-on-unplug, Belkin support, various
- *              cleanups for problems not yet seen in the field. (db)
- * 17-oct-2001  Handle "Advance USBNET" product, like Belkin/eTEK devices,
- *              from Ioannis Mavroukakis <i.mavroukakis@btinternet.com>;
- *              rx unlinks somehow weren't async; minor cleanup.
- * 03-nov-2001  Merged GeneSys driver; original code from Jiun-Jie Huang
- *              <huangjj@genesyslogic.com.tw>, updated by Stanislav Brabec
- *              <utx@penguin.cz>.  Made framing options (NetChip/GeneSys)
- *              tie mostly to (sub)driver info.  Workaround some PL-2302
- *              chips that seem to reject SET_INTERFACE requests.
- *
- * 06-apr-2002  Added ethtool support, based on a patch from Brad Hards.
- *              Level of diagnostics is more configurable; they use device
- *              location (usb_device->devpath) instead of address (2.5).
- *              For tx_fixup, memflags can't be NOIO.
- * 07-may-2002  Generalize/cleanup keventd support, handling rx stalls (mostly
- *              for USB 2.0 TTs) and memory shortages (potential) too. (db)
- *              Use "locally assigned" IEEE802 address space. (Brad Hards)
- * 18-oct-2002  Support for Zaurus (Pavel Machek), related cleanup (db).
- * 14-dec-2002  Remove Zaurus-private crc32 code (Pavel); 2.5 oops fix,
- *              cleanups and stubbed PXA-250 support (db), fix for framing
- *              issues on Z, net1080, and gl620a (Toby Milne)
- *
- * 31-mar-2003  Use endpoint descriptors:  high speed support, simpler sa1100
- *              vs pxa25x, and CDC Ethernet.  Throttle down log floods on
- *              disconnect; other cleanups. (db)  Flush net1080 fifos
- *              after several sequential framing errors. (Johannes Erdfelt)
- * 22-aug-2003  AX8817X support (Dave Hollis).
- *
- * 14-jun-2004  Trivial patch for AX8817X based Buffalo LUA-U2-KTX in Japan
- *              (Neil Bortnak)
- * 03-nov-2004  Trivial patch for KC2190 (KC-190) chip. (Jonathan McDowell)
- *
- * 01-feb-2005  AX88772 support (Phil Chang & Dave Hollis)
- *-------------------------------------------------------------------------*/
+ * These devices usually differ in terms of control protocols (if they
+ * even have one!) and sometimes they define new framing to wrap or batch
+ * Ethernet packets.  Otherwise, they talk to USB pretty much the same,
+ * so interface (un)binding, endpoint I/O queues, fault handling, and other
+ * issues can usefully be addressed by this framework.
+ */
 
 // #define      DEBUG                   // error path messages, extra info
 // #define      VERBOSE                 // more; success messages
@@ -302,77 +221,6 @@ void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 
 
-#ifdef CONFIG_USB_PL2301
-#define HAVE_HARDWARE
-
-/*-------------------------------------------------------------------------
- *
- * Prolific PL-2301/PL-2302 driver ... http://www.prolifictech.com
- *
- * The protocol and handshaking used here should be bug-compatible
- * with the Linux 2.2 "plusb" driver, by Deti Fliegl.
- *
- *-------------------------------------------------------------------------*/
-
-/*
- * Bits 0-4 can be used for software handshaking; they're set from
- * one end, cleared from the other, "read" with the interrupt byte.
- */
-#define PL_S_EN         (1<<7)          /* (feature only) suspend enable */
-/* reserved bit -- rx ready (6) ? */
-#define PL_TX_READY     (1<<5)          /* (interrupt only) transmit ready */
-#define PL_RESET_OUT    (1<<4)          /* reset output pipe */
-#define PL_RESET_IN     (1<<3)          /* reset input pipe */
-#define PL_TX_C         (1<<2)          /* transmission complete */
-#define PL_TX_REQ       (1<<1)          /* transmission received */
-#define PL_PEER_E       (1<<0)          /* peer exists */
-
-static inline int
-pl_vendor_req (struct usbnet *dev, u8 req, u8 val, u8 index)
-{
-        return usb_control_msg (dev->udev,
-                usb_rcvctrlpipe (dev->udev, 0),
-                req,
-                USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
-                val, index,
-                NULL, 0,
-                USB_CTRL_GET_TIMEOUT);
-}
-
-static inline int
-pl_clear_QuickLink_features (struct usbnet *dev, int val)
-{
-        return pl_vendor_req (dev, 1, (u8) val, 0);
-}
-
-static inline int
-pl_set_QuickLink_features (struct usbnet *dev, int val)
-{
-        return pl_vendor_req (dev, 3, (u8) val, 0);
-}
-
-/*-------------------------------------------------------------------------*/
-
-static int pl_reset (struct usbnet *dev)
-{
-        /* some units seem to need this reset, others reject it utterly.
-         * FIXME be more like "naplink" or windows drivers.
-         */
-        (void) pl_set_QuickLink_features (dev,
-                PL_S_EN|PL_RESET_OUT|PL_RESET_IN|PL_PEER_E);
-        return 0;
-}
-
-static const struct driver_info prolific_info = {
-        .description =  "Prolific PL-2301/PL-2302",
-        .flags =        FLAG_NO_SETINT,
-                /* some PL-2302 versions seem to fail usb_set_interface() */
-        .reset =        pl_reset,
-};
-
-#endif /* CONFIG_USB_PL2301 */
-
-
 /*-------------------------------------------------------------------------
  *
  * Network Device Driver (peer link to "Host Device", from USB host)
@@ -1356,60 +1204,22 @@ EXPORT_SYMBOL_GPL(usbnet_resume);
 
 /*-------------------------------------------------------------------------*/
 
-#ifndef HAVE_HARDWARE
-#error You need to configure some hardware for this driver
-#endif
-
-/*
- * chip vendor names won't normally be on the cables, and
- * may not be on the device.
- */
-
-static const struct usb_device_id       products [] = {
-
-#ifdef CONFIG_USB_PL2301
-{
-        USB_DEVICE (0x067b, 0x0000),    // PL-2301
-        .driver_info =  (unsigned long) &prolific_info,
-}, {
-        USB_DEVICE (0x067b, 0x0001),    // PL-2302
-        .driver_info =  (unsigned long) &prolific_info,
-},
-#endif
-        { },            // END
-};
-MODULE_DEVICE_TABLE (usb, products);
-
-static struct usb_driver usbnet_driver = {
-        .owner =        THIS_MODULE,
-        .name =         driver_name,
-        .id_table =     products,
-        .probe =        usbnet_probe,
-        .disconnect =   usbnet_disconnect,
-        .suspend =      usbnet_suspend,
-        .resume =       usbnet_resume,
-};
-
-/*-------------------------------------------------------------------------*/
-
 static int __init usbnet_init(void)
 {
-        // compiler should optimize these out
+        /* compiler should optimize this out */
         BUG_ON (sizeof (((struct sk_buff *)0)->cb)
                         < sizeof (struct skb_data));
 
         random_ether_addr(node_id);
-
-        return usb_register(&usbnet_driver);
+        return 0;
 }
 module_init(usbnet_init);
 
 static void __exit usbnet_exit(void)
 {
-        usb_deregister(&usbnet_driver);
 }
 module_exit(usbnet_exit);
 
 MODULE_AUTHOR("David Brownell");
-MODULE_DESCRIPTION("USB Host-to-Host Link Drivers (numerous vendors)");
+MODULE_DESCRIPTION("USB network driver framework");
 MODULE_LICENSE("GPL");