[PATCH] USB: usbnet (5/9) module for genesys gl620a cables

This moves the GeneSys GL620USB-A support into its own driver file.
It also fixes a "return wrong skb" glitch in the rx unbatching, as
recently reported, and adds some missing byteswaps in the special
"genelink" headers (so it might now work on big-endian Linux).

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

1 files changed, 407 insertions, 0 deletions

diff --git a/drivers/usb/net/gl620a.c b/drivers/usb/net/gl620a.c
new file mode 100644
index 000000000000..c8763ae33c73
--- /dev/null
+++ b/drivers/usb/net/gl620a.c
@@ -0,0 +1,407 @@
+/*
+ * GeneSys GL620USB-A based links
+ * Copyright (C) 2001 by Jiun-Jie Huang <huangjj@genesyslogic.com.tw>
+ * Copyright (C) 2001 by Stanislav Brabec <utx@penguin.cz>
+ *
+ * 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"
+
+
+/*
+ * GeneSys GL620USB-A (www.genesyslogic.com.tw)
+ *
+ * ... should partially interop with the Win32 driver for this hardware.
+ * The GeneSys docs imply there's some NDIS issue motivating this framing.
+ *
+ * Some info from GeneSys:
+ *  - GL620USB-A is full duplex; GL620USB is only half duplex for bulk.
+ *    (Some cables, like the BAFO-100c, use the half duplex version.)
+ *  - For the full duplex model, the low bit of the version code says
+ *    which side is which ("left/right").
+ *  - For the half duplex type, a control/interrupt handshake settles
+ *    the transfer direction.  (That's disabled here, partially coded.)
+ *    A control URB would block until other side writes an interrupt.
+ *
+ * Original code from Jiun-Jie Huang <huangjj@genesyslogic.com.tw>
+ * and merged into "usbnet" by Stanislav Brabec <utx@penguin.cz>.
+ */
+
+// control msg write command
+#define GENELINK_CONNECT_WRITE                  0xF0
+// interrupt pipe index
+#define GENELINK_INTERRUPT_PIPE                 0x03
+// interrupt read buffer size
+#define INTERRUPT_BUFSIZE                       0x08
+// interrupt pipe interval value
+#define GENELINK_INTERRUPT_INTERVAL             0x10
+// max transmit packet number per transmit
+#define GL_MAX_TRANSMIT_PACKETS                 32
+// max packet length
+#define GL_MAX_PACKET_LEN                       1514
+// max receive buffer size
+#define GL_RCV_BUF_SIZE         \
+        (((GL_MAX_PACKET_LEN + 4) * GL_MAX_TRANSMIT_PACKETS) + 4)
+
+struct gl_packet {
+        u32             packet_length;
+        char            packet_data [1];
+};
+
+struct gl_header {
+        u32                     packet_count;
+        struct gl_packet        packets;
+};
+
+#ifdef  GENELINK_ACK
+
+// FIXME:  this code is incomplete, not debugged; it doesn't
+// handle interrupts correctly; it should use the generic
+// status IRQ code (which didn't exist back in 2001).
+
+struct gl_priv {
+        struct urb      *irq_urb;
+        char            irq_buf [INTERRUPT_BUFSIZE];
+};
+
+static inline int gl_control_write(struct usbnet *dev, u8 request, u16 value)
+{
+        int retval;
+
+        retval = usb_control_msg(dev->udev,
+                      usb_sndctrlpipe(dev->udev, 0),
+                      request,
+                      USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
+                      value,
+                      0,                        // index
+                      0,                        // data buffer
+                      0,                        // size
+                      USB_CTRL_SET_TIMEOUT);
+        return retval;
+}
+
+static void gl_interrupt_complete(struct urb *urb, struct pt_regs *regs)
+{
+        int status = urb->status;
+
+        switch (status) {
+        case 0:
+                /* success */
+                break;
+        case -ECONNRESET:
+        case -ENOENT:
+        case -ESHUTDOWN:
+                /* this urb is terminated, clean up */
+                dbg("%s - urb shutting down with status: %d",
+                                __FUNCTION__, status);
+                return;
+        default:
+                dbg("%s - nonzero urb status received: %d",
+                                __FUNCTION__, urb->status);
+        }
+
+        status = usb_submit_urb(urb, GFP_ATOMIC);
+        if (status)
+                err("%s - usb_submit_urb failed with result %d",
+                     __FUNCTION__, status);
+}
+
+static int gl_interrupt_read(struct usbnet *dev)
+{
+        struct gl_priv  *priv = dev->priv_data;
+        int             retval;
+
+        // issue usb interrupt read
+        if (priv && priv->irq_urb) {
+                // submit urb
+                if ((retval = usb_submit_urb(priv->irq_urb, GFP_KERNEL)) != 0)
+                        dbg("gl_interrupt_read: submit fail - %X...", retval);
+                else
+                        dbg("gl_interrupt_read: submit success...");
+        }
+
+        return 0;
+}
+
+// check whether another side is connected
+static int genelink_check_connect(struct usbnet *dev)
+{
+        int                     retval;
+
+        dbg("genelink_check_connect...");
+
+        // detect whether another side is connected
+        if ((retval = gl_control_write(dev, GENELINK_CONNECT_WRITE, 0)) != 0) {
+                dbg("%s: genelink_check_connect write fail - %X",
+                        dev->net->name, retval);
+                return retval;
+        }
+
+        // usb interrupt read to ack another side
+        if ((retval = gl_interrupt_read(dev)) != 0) {
+                dbg("%s: genelink_check_connect read fail - %X",
+                        dev->net->name, retval);
+                return retval;
+        }
+
+        dbg("%s: genelink_check_connect read success", dev->net->name);
+        return 0;
+}
+
+// allocate and initialize the private data for genelink
+static int genelink_init(struct usbnet *dev)
+{
+        struct gl_priv *priv;
+
+        // allocate the private data structure
+        if ((priv = kmalloc(sizeof *priv, GFP_KERNEL)) == 0) {
+                dbg("%s: cannot allocate private data per device",
+                        dev->net->name);
+                return -ENOMEM;
+        }
+
+        // allocate irq urb
+        if ((priv->irq_urb = usb_alloc_urb(0, GFP_KERNEL)) == 0) {
+                dbg("%s: cannot allocate private irq urb per device",
+                        dev->net->name);
+                kfree(priv);
+                return -ENOMEM;
+        }
+
+        // fill irq urb
+        usb_fill_int_urb(priv->irq_urb, dev->udev,
+                usb_rcvintpipe(dev->udev, GENELINK_INTERRUPT_PIPE),
+                priv->irq_buf, INTERRUPT_BUFSIZE,
+                gl_interrupt_complete, 0,
+                GENELINK_INTERRUPT_INTERVAL);
+
+        // set private data pointer
+        dev->priv_data = priv;
+
+        return 0;
+}
+
+// release the private data
+static int genelink_free(struct usbnet *dev)
+{
+        struct gl_priv  *priv = dev->priv_data;
+
+        if (!priv)
+                return 0;
+
+// FIXME:  can't cancel here; it's synchronous, and
+// should have happened earlier in any case (interrupt
+// handling needs to be generic)
+
+        // cancel irq urb first
+        usb_kill_urb(priv->irq_urb);
+
+        // free irq urb
+        usb_free_urb(priv->irq_urb);
+
+        // free the private data structure
+        kfree(priv);
+
+        return 0;
+}
+
+#endif
+
+static int genelink_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
+{
+        struct gl_header        *header;
+        struct gl_packet        *packet;
+        struct sk_buff          *gl_skb;
+        u32                     size;
+
+        header = (struct gl_header *) skb->data;
+
+        // get the packet count of the received skb
+        le32_to_cpus(&header->packet_count);
+        if ((header->packet_count > GL_MAX_TRANSMIT_PACKETS)
+                        || (header->packet_count < 0)) {
+                dbg("genelink: invalid received packet count %d",
+                        header->packet_count);
+                return 0;
+        }
+
+        // set the current packet pointer to the first packet
+        packet = &header->packets;
+
+        // decrement the length for the packet count size 4 bytes
+        skb_pull(skb, 4);
+
+        while (header->packet_count > 1) {
+                // get the packet length
+                size = le32_to_cpu(packet->packet_length);
+
+                // this may be a broken packet
+                if (size > GL_MAX_PACKET_LEN) {
+                        dbg("genelink: invalid rx length %d", size);
+                        return 0;
+                }
+
+                // allocate the skb for the individual packet
+                gl_skb = alloc_skb(size, GFP_ATOMIC);
+                if (gl_skb) {
+
+                        // copy the packet data to the new skb
+                        memcpy(skb_put(gl_skb, size),
+                                        packet->packet_data, size);
+                        usbnet_skb_return(dev, gl_skb);
+                }
+
+                // advance to the next packet
+                packet = (struct gl_packet *)
+                        &packet->packet_data [size];
+                header->packet_count--;
+
+                // shift the data pointer to the next gl_packet
+                skb_pull(skb, size + 4);
+        }
+
+        // skip the packet length field 4 bytes
+        skb_pull(skb, 4);
+
+        if (skb->len > GL_MAX_PACKET_LEN) {
+                dbg("genelink: invalid rx length %d", skb->len);
+                return 0;
+        }
+        return 1;
+}
+
+static struct sk_buff *
+genelink_tx_fixup(struct usbnet *dev, struct sk_buff *skb, unsigned flags)
+{
+        int     padlen;
+        int     length = skb->len;
+        int     headroom = skb_headroom(skb);
+        int     tailroom = skb_tailroom(skb);
+        u32     *packet_count;
+        u32     *packet_len;
+
+        // FIXME:  magic numbers, bleech
+        padlen = ((skb->len + (4 + 4*1)) % 64) ? 0 : 1;
+
+        if ((!skb_cloned(skb))
+                        && ((headroom + tailroom) >= (padlen + (4 + 4*1)))) {
+                if ((headroom < (4 + 4*1)) || (tailroom < padlen)) {
+                        skb->data = memmove(skb->head + (4 + 4*1),
+                                             skb->data, skb->len);
+                        skb->tail = skb->data + skb->len;
+                }
+        } else {
+                struct sk_buff  *skb2;
+                skb2 = skb_copy_expand(skb, (4 + 4*1) , padlen, flags);
+                dev_kfree_skb_any(skb);
+                skb = skb2;
+                if (!skb)
+                        return NULL;
+        }
+
+        // attach the packet count to the header
+        packet_count = (u32 *) skb_push(skb, (4 + 4*1));
+        packet_len = packet_count + 1;
+
+        *packet_count = cpu_to_le32(1);
+        *packet_len = cpu_to_le32(length);
+
+        // add padding byte
+        if ((skb->len % dev->maxpacket) == 0)
+                skb_put(skb, 1);
+
+        return skb;
+}
+
+static int genelink_bind(struct usbnet *dev, struct usb_interface *intf)
+{
+        dev->hard_mtu = GL_RCV_BUF_SIZE;
+        dev->net->hard_header_len += 4;
+        dev->in = usb_rcvbulkpipe(dev->udev, dev->driver_info->in);
+        dev->out = usb_sndbulkpipe(dev->udev, dev->driver_info->out);
+        return 0;
+}
+
+static const struct driver_info genelink_info = {
+        .description =  "Genesys GeneLink",
+        .flags =        FLAG_FRAMING_GL | FLAG_NO_SETINT,
+        .bind =         genelink_bind,
+        .rx_fixup =     genelink_rx_fixup,
+        .tx_fixup =     genelink_tx_fixup,
+
+        .in = 1, .out = 2,
+
+#ifdef  GENELINK_ACK
+        .check_connect =genelink_check_connect,
+#endif
+};
+
+static const struct usb_device_id       products [] = {
+
+{
+        USB_DEVICE(0x05e3, 0x0502),     // GL620USB-A
+        .driver_info =  (unsigned long) &genelink_info,
+},
+        /* NOT: USB_DEVICE(0x05e3, 0x0501),     // GL620USB
+         * that's half duplex, not currently supported
+         */
+        { },            // END
+};
+MODULE_DEVICE_TABLE(usb, products);
+
+static struct usb_driver gl620a_driver = {
+        .owner =        THIS_MODULE,
+        .name =         "gl620a",
+        .id_table =     products,
+        .probe =        usbnet_probe,
+        .disconnect =   usbnet_disconnect,
+        .suspend =      usbnet_suspend,
+        .resume =       usbnet_resume,
+};
+
+static int __init usbnet_init(void)
+{
+        return usb_register(&gl620a_driver);
+}
+module_init(usbnet_init);
+
+static void __exit usbnet_exit(void)
+{
+        usb_deregister(&gl620a_driver);
+}
+module_exit(usbnet_exit);
+
+MODULE_AUTHOR("Jiun-Jie Huang");
+MODULE_DESCRIPTION("GL620-USB-A Host-to-Host Link cables");
+MODULE_LICENSE("GPL");
+