[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 <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: David Brownell

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

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

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");