// SPDX-License-Identifier: GPL-2.0-or-later
/*
* PL-2301/2302 USB host-to-host link cables
* Copyright (C) 2000-2005 by David Brownell
*/
// #define DEBUG // error path messages, extra info
// #define VERBOSE // more; success messages
#include <linux/module.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 <linux/usb/usbnet.h>
/*
* Prolific PL-2301/PL-2302 driver ... http://www.prolific.com.tw/
*
* 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 developers) 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.
*
* NOTE: pl2501 has several modes, including pl2301 and pl2302
* compatibility. Some docs suggest the difference between 2301
* and 2302 is only to make MS-Windows use a different driver...
*
* pl25a1 glue based on patch from Tony Gibbs. Prolific "docs" on
* this chip are as usual incomplete about what control messages
* are supported.
*/
/*
* 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 usbnet_read_cmd(dev, req,
USB_DIR_IN | USB_TYPE_VENDOR |
USB_RECIP_DEVICE,
val, index, NULL, 0);
}
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)
{
int status;
/* some units seem to need this reset, others reject it utterly.
* FIXME be more like "naplink" or windows drivers.
*/
status = pl_set_QuickLink_features(dev,
PL_S_EN|PL_RESET_OUT|PL_RESET_IN|PL_PEER_E);
if (status != 0 && netif_msg_probe(dev))
netif_dbg(dev, link, dev->net, "pl_reset --> %d\n", status);
return 0;
}
static const struct driver_info prolific_info = {
.description = "Prolific PL-2301/PL-2302/PL-25A1/PL-27A1",
.flags = FLAG_POINTTOPOINT | 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 [] = {
/* full speed cables */
{
USB_DEVICE(0x067b, 0x0000), // PL-2301
.driver_info = (unsigned long) &prolific_info,
}, {
USB_DEVICE(0x067b, 0x0001), // PL-2302
.driver_info = (unsigned long) &prolific_info,
},
/* high speed cables */
{
USB_DEVICE(0x067b, 0x25a1), /* PL-25A1, no eeprom */
.driver_info = (unsigned long) &prolific_info,
}, {
USB_DEVICE(0x050d, 0x258a), /* Belkin F5U258/F5U279 (PL-25A1) */
.driver_info = (unsigned long) &prolific_info,
}, {
USB_DEVICE(0x3923, 0x7825), /* National Instruments USB
* Host-to-Host Cable
*/
.driver_info = (unsigned long) &prolific_info,
},
/* super speed cables */
{
USB_DEVICE(0x067b, 0x27a1), /* PL-27A1, no eeprom
* also: goobay Active USB 3.0
* Data Link,
* Unitek Y-3501
*/
.driver_info = (unsigned long) &prolific_info,
},
{ }, // END
};
MODULE_DEVICE_TABLE(usb, products);
static struct usb_driver plusb_driver = {
.name = "plusb",
.id_table = products,
.probe = usbnet_probe,
.disconnect = usbnet_disconnect,
.suspend = usbnet_suspend,
.resume = usbnet_resume,
.disable_hub_initiated_lpm = 1,
};
module_usb_driver(plusb_driver);
MODULE_AUTHOR("David Brownell");
MODULE_DESCRIPTION("Prolific PL-2301/2302/25A1/27A1 USB Host to Host Link Driver");
MODULE_LICENSE("GPL");
