Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / net / usb / cx82310_eth.c
diff --git a/kernel/drivers/net/usb/cx82310_eth.c b/kernel/drivers/net/usb/cx82310_eth.c
new file mode 100644 (file)
index 0000000..e221bfc
--- /dev/null
@@ -0,0 +1,353 @@
+/*
+ * Driver for USB ethernet port of Conexant CX82310-based ADSL routers
+ * Copyright (C) 2010 by Ondrej Zary
+ * some parts inspired by the cxacru driver
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#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>
+
+enum cx82310_cmd {
+       CMD_START               = 0x84, /* no effect? */
+       CMD_STOP                = 0x85, /* no effect? */
+       CMD_GET_STATUS          = 0x90, /* returns nothing? */
+       CMD_GET_MAC_ADDR        = 0x91, /* read MAC address */
+       CMD_GET_LINK_STATUS     = 0x92, /* not useful, link is always up */
+       CMD_ETHERNET_MODE       = 0x99, /* unknown, needed during init */
+};
+
+enum cx82310_status {
+       STATUS_UNDEFINED,
+       STATUS_SUCCESS,
+       STATUS_ERROR,
+       STATUS_UNSUPPORTED,
+       STATUS_UNIMPLEMENTED,
+       STATUS_PARAMETER_ERROR,
+       STATUS_DBG_LOOPBACK,
+};
+
+#define CMD_PACKET_SIZE        64
+#define CMD_TIMEOUT    100
+#define CMD_REPLY_RETRY 5
+
+#define CX82310_MTU    1514
+#define CMD_EP         0x01
+
+/*
+ * execute control command
+ *  - optionally send some data (command parameters)
+ *  - optionally wait for the reply
+ *  - optionally read some data from the reply
+ */
+static int cx82310_cmd(struct usbnet *dev, enum cx82310_cmd cmd, bool reply,
+                      u8 *wdata, int wlen, u8 *rdata, int rlen)
+{
+       int actual_len, retries, ret;
+       struct usb_device *udev = dev->udev;
+       u8 *buf = kzalloc(CMD_PACKET_SIZE, GFP_KERNEL);
+
+       if (!buf)
+               return -ENOMEM;
+
+       /* create command packet */
+       buf[0] = cmd;
+       if (wdata)
+               memcpy(buf + 4, wdata, min_t(int, wlen, CMD_PACKET_SIZE - 4));
+
+       /* send command packet */
+       ret = usb_bulk_msg(udev, usb_sndbulkpipe(udev, CMD_EP), buf,
+                          CMD_PACKET_SIZE, &actual_len, CMD_TIMEOUT);
+       if (ret < 0) {
+               if (cmd != CMD_GET_LINK_STATUS)
+                       dev_err(&dev->udev->dev, "send command %#x: error %d\n",
+                               cmd, ret);
+               goto end;
+       }
+
+       if (reply) {
+               /* wait for reply, retry if it's empty */
+               for (retries = 0; retries < CMD_REPLY_RETRY; retries++) {
+                       ret = usb_bulk_msg(udev, usb_rcvbulkpipe(udev, CMD_EP),
+                                          buf, CMD_PACKET_SIZE, &actual_len,
+                                          CMD_TIMEOUT);
+                       if (ret < 0) {
+                               if (cmd != CMD_GET_LINK_STATUS)
+                                       dev_err(&dev->udev->dev,
+                                               "reply receive error %d\n",
+                                               ret);
+                               goto end;
+                       }
+                       if (actual_len > 0)
+                               break;
+               }
+               if (actual_len == 0) {
+                       dev_err(&dev->udev->dev, "no reply to command %#x\n",
+                               cmd);
+                       ret = -EIO;
+                       goto end;
+               }
+               if (buf[0] != cmd) {
+                       dev_err(&dev->udev->dev,
+                               "got reply to command %#x, expected: %#x\n",
+                               buf[0], cmd);
+                       ret = -EIO;
+                       goto end;
+               }
+               if (buf[1] != STATUS_SUCCESS) {
+                       dev_err(&dev->udev->dev, "command %#x failed: %#x\n",
+                               cmd, buf[1]);
+                       ret = -EIO;
+                       goto end;
+               }
+               if (rdata)
+                       memcpy(rdata, buf + 4,
+                              min_t(int, rlen, CMD_PACKET_SIZE - 4));
+       }
+end:
+       kfree(buf);
+       return ret;
+}
+
+#define partial_len    data[0]         /* length of partial packet data */
+#define partial_rem    data[1]         /* remaining (missing) data length */
+#define partial_data   data[2]         /* partial packet data */
+
+static int cx82310_bind(struct usbnet *dev, struct usb_interface *intf)
+{
+       int ret;
+       char buf[15];
+       struct usb_device *udev = dev->udev;
+       u8 link[3];
+       int timeout = 50;
+
+       /* avoid ADSL modems - continue only if iProduct is "USB NET CARD" */
+       if (usb_string(udev, udev->descriptor.iProduct, buf, sizeof(buf)) > 0
+           && strcmp(buf, "USB NET CARD")) {
+               dev_info(&udev->dev, "ignoring: probably an ADSL modem\n");
+               return -ENODEV;
+       }
+
+       ret = usbnet_get_endpoints(dev, intf);
+       if (ret)
+               return ret;
+
+       /*
+        * this must not include ethernet header as the device can send partial
+        * packets with no header (and sometimes even empty URBs)
+        */
+       dev->net->hard_header_len = 0;
+       /* we can send at most 1514 bytes of data (+ 2-byte header) per URB */
+       dev->hard_mtu = CX82310_MTU + 2;
+       /* we can receive URBs up to 4KB from the device */
+       dev->rx_urb_size = 4096;
+
+       dev->partial_data = (unsigned long) kmalloc(dev->hard_mtu, GFP_KERNEL);
+       if (!dev->partial_data)
+               return -ENOMEM;
+
+       /* wait for firmware to become ready (indicated by the link being up) */
+       while (--timeout) {
+               ret = cx82310_cmd(dev, CMD_GET_LINK_STATUS, true, NULL, 0,
+                                 link, sizeof(link));
+               /* the command can time out during boot - it's not an error */
+               if (!ret && link[0] == 1 && link[2] == 1)
+                       break;
+               msleep(500);
+       }
+       if (!timeout) {
+               dev_err(&udev->dev, "firmware not ready in time\n");
+               return -ETIMEDOUT;
+       }
+
+       /* enable ethernet mode (?) */
+       ret = cx82310_cmd(dev, CMD_ETHERNET_MODE, true, "\x01", 1, NULL, 0);
+       if (ret) {
+               dev_err(&udev->dev, "unable to enable ethernet mode: %d\n",
+                       ret);
+               goto err;
+       }
+
+       /* get the MAC address */
+       ret = cx82310_cmd(dev, CMD_GET_MAC_ADDR, true, NULL, 0,
+                         dev->net->dev_addr, ETH_ALEN);
+       if (ret) {
+               dev_err(&udev->dev, "unable to read MAC address: %d\n", ret);
+               goto err;
+       }
+
+       /* start (does not seem to have any effect?) */
+       ret = cx82310_cmd(dev, CMD_START, false, NULL, 0, NULL, 0);
+       if (ret)
+               goto err;
+
+       return 0;
+err:
+       kfree((void *)dev->partial_data);
+       return ret;
+}
+
+static void cx82310_unbind(struct usbnet *dev, struct usb_interface *intf)
+{
+       kfree((void *)dev->partial_data);
+}
+
+/*
+ * RX is NOT easy - we can receive multiple packets per skb, each having 2-byte
+ * packet length at the beginning.
+ * The last packet might be incomplete (when it crosses the 4KB URB size),
+ * continuing in the next skb (without any headers).
+ * If a packet has odd length, there is one extra byte at the end (before next
+ * packet or at the end of the URB).
+ */
+static int cx82310_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
+{
+       int len;
+       struct sk_buff *skb2;
+
+       /*
+        * If the last skb ended with an incomplete packet, this skb contains
+        * end of that packet at the beginning.
+        */
+       if (dev->partial_rem) {
+               len = dev->partial_len + dev->partial_rem;
+               skb2 = alloc_skb(len, GFP_ATOMIC);
+               if (!skb2)
+                       return 0;
+               skb_put(skb2, len);
+               memcpy(skb2->data, (void *)dev->partial_data,
+                      dev->partial_len);
+               memcpy(skb2->data + dev->partial_len, skb->data,
+                      dev->partial_rem);
+               usbnet_skb_return(dev, skb2);
+               skb_pull(skb, (dev->partial_rem + 1) & ~1);
+               dev->partial_rem = 0;
+               if (skb->len < 2)
+                       return 1;
+       }
+
+       /* a skb can contain multiple packets */
+       while (skb->len > 1) {
+               /* first two bytes are packet length */
+               len = skb->data[0] | (skb->data[1] << 8);
+               skb_pull(skb, 2);
+
+               /* if last packet in the skb, let usbnet to process it */
+               if (len == skb->len || len + 1 == skb->len) {
+                       skb_trim(skb, len);
+                       break;
+               }
+
+               if (len > CX82310_MTU) {
+                       dev_err(&dev->udev->dev, "RX packet too long: %d B\n",
+                               len);
+                       return 0;
+               }
+
+               /* incomplete packet, save it for the next skb */
+               if (len > skb->len) {
+                       dev->partial_len = skb->len;
+                       dev->partial_rem = len - skb->len;
+                       memcpy((void *)dev->partial_data, skb->data,
+                              dev->partial_len);
+                       skb_pull(skb, skb->len);
+                       break;
+               }
+
+               skb2 = alloc_skb(len, GFP_ATOMIC);
+               if (!skb2)
+                       return 0;
+               skb_put(skb2, len);
+               memcpy(skb2->data, skb->data, len);
+               /* process the packet */
+               usbnet_skb_return(dev, skb2);
+
+               skb_pull(skb, (len + 1) & ~1);
+       }
+
+       /* let usbnet process the last packet */
+       return 1;
+}
+
+/* TX is easy, just add 2 bytes of length at the beginning */
+static struct sk_buff *cx82310_tx_fixup(struct usbnet *dev, struct sk_buff *skb,
+                                      gfp_t flags)
+{
+       int len = skb->len;
+
+       if (skb_headroom(skb) < 2) {
+               struct sk_buff *skb2 = skb_copy_expand(skb, 2, 0, flags);
+               dev_kfree_skb_any(skb);
+               skb = skb2;
+               if (!skb)
+                       return NULL;
+       }
+       skb_push(skb, 2);
+
+       skb->data[0] = len;
+       skb->data[1] = len >> 8;
+
+       return skb;
+}
+
+
+static const struct driver_info        cx82310_info = {
+       .description    = "Conexant CX82310 USB ethernet",
+       .flags          = FLAG_ETHER,
+       .bind           = cx82310_bind,
+       .unbind         = cx82310_unbind,
+       .rx_fixup       = cx82310_rx_fixup,
+       .tx_fixup       = cx82310_tx_fixup,
+};
+
+#define USB_DEVICE_CLASS(vend, prod, cl, sc, pr) \
+       .match_flags = USB_DEVICE_ID_MATCH_DEVICE | \
+                      USB_DEVICE_ID_MATCH_DEV_INFO, \
+       .idVendor = (vend), \
+       .idProduct = (prod), \
+       .bDeviceClass = (cl), \
+       .bDeviceSubClass = (sc), \
+       .bDeviceProtocol = (pr)
+
+static const struct usb_device_id products[] = {
+       {
+               USB_DEVICE_CLASS(0x0572, 0xcb01, 0xff, 0, 0),
+               .driver_info = (unsigned long) &cx82310_info
+       },
+       { },
+};
+MODULE_DEVICE_TABLE(usb, products);
+
+static struct usb_driver cx82310_driver = {
+       .name           = "cx82310_eth",
+       .id_table       = products,
+       .probe          = usbnet_probe,
+       .disconnect     = usbnet_disconnect,
+       .suspend        = usbnet_suspend,
+       .resume         = usbnet_resume,
+       .disable_hub_initiated_lpm = 1,
+};
+
+module_usb_driver(cx82310_driver);
+
+MODULE_AUTHOR("Ondrej Zary");
+MODULE_DESCRIPTION("Conexant CX82310-based ADSL router USB ethernet driver");
+MODULE_LICENSE("GPL");