|  | // SPDX-License-Identifier: GPL-2.0-or-later | 
|  | /* | 
|  | * Driver for USB ethernet port of Conexant CX82310-based ADSL routers | 
|  | * Copyright (C) 2010 by Ondrej Zary | 
|  | * some parts inspired by the cxacru driver | 
|  | */ | 
|  |  | 
|  | #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 | 
|  |  | 
|  | struct cx82310_priv { | 
|  | struct work_struct reenable_work; | 
|  | struct usbnet *dev; | 
|  | }; | 
|  |  | 
|  | /* | 
|  | * 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) | 
|  | netdev_err(dev->net, "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) | 
|  | netdev_err(dev->net, "reply receive error %d\n", | 
|  | ret); | 
|  | goto end; | 
|  | } | 
|  | if (actual_len > 0) | 
|  | break; | 
|  | } | 
|  | if (actual_len == 0) { | 
|  | netdev_err(dev->net, "no reply to command %#x\n", cmd); | 
|  | ret = -EIO; | 
|  | goto end; | 
|  | } | 
|  | if (buf[0] != cmd) { | 
|  | netdev_err(dev->net, "got reply to command %#x, expected: %#x\n", | 
|  | buf[0], cmd); | 
|  | ret = -EIO; | 
|  | goto end; | 
|  | } | 
|  | if (buf[1] != STATUS_SUCCESS) { | 
|  | netdev_err(dev->net, "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; | 
|  | } | 
|  |  | 
|  | static int cx82310_enable_ethernet(struct usbnet *dev) | 
|  | { | 
|  | int ret = cx82310_cmd(dev, CMD_ETHERNET_MODE, true, "\x01", 1, NULL, 0); | 
|  |  | 
|  | if (ret) | 
|  | netdev_err(dev->net, "unable to enable ethernet mode: %d\n", | 
|  | ret); | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | static void cx82310_reenable_work(struct work_struct *work) | 
|  | { | 
|  | struct cx82310_priv *priv = container_of(work, struct cx82310_priv, | 
|  | reenable_work); | 
|  | cx82310_enable_ethernet(priv->dev); | 
|  | } | 
|  |  | 
|  | #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; | 
|  | struct cx82310_priv *priv; | 
|  | u8 addr[ETH_ALEN]; | 
|  |  | 
|  | /* 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; | 
|  |  | 
|  | priv = kzalloc(sizeof(*priv), GFP_KERNEL); | 
|  | if (!priv) { | 
|  | ret = -ENOMEM; | 
|  | goto err_partial; | 
|  | } | 
|  | dev->driver_priv = priv; | 
|  | INIT_WORK(&priv->reenable_work, cx82310_reenable_work); | 
|  | priv->dev = dev; | 
|  |  | 
|  | /* 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) { | 
|  | netdev_err(dev->net, "firmware not ready in time\n"); | 
|  | ret = -ETIMEDOUT; | 
|  | goto err; | 
|  | } | 
|  |  | 
|  | /* enable ethernet mode (?) */ | 
|  | ret = cx82310_enable_ethernet(dev); | 
|  | if (ret) | 
|  | goto err; | 
|  |  | 
|  | /* get the MAC address */ | 
|  | ret = cx82310_cmd(dev, CMD_GET_MAC_ADDR, true, NULL, 0, addr, ETH_ALEN); | 
|  | if (ret) { | 
|  | netdev_err(dev->net, "unable to read MAC address: %d\n", ret); | 
|  | goto err; | 
|  | } | 
|  | eth_hw_addr_set(dev->net, addr); | 
|  |  | 
|  | /* 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(dev->driver_priv); | 
|  | err_partial: | 
|  | kfree((void *)dev->partial_data); | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | static void cx82310_unbind(struct usbnet *dev, struct usb_interface *intf) | 
|  | { | 
|  | struct cx82310_priv *priv = dev->driver_priv; | 
|  |  | 
|  | kfree((void *)dev->partial_data); | 
|  | cancel_work_sync(&priv->reenable_work); | 
|  | kfree(dev->driver_priv); | 
|  | } | 
|  |  | 
|  | /* | 
|  | * 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; | 
|  | struct cx82310_priv *priv = dev->driver_priv; | 
|  |  | 
|  | /* | 
|  | * 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 == 0xffff) { | 
|  | netdev_info(dev->net, "router was rebooted, re-enabling ethernet mode"); | 
|  | schedule_work(&priv->reenable_work); | 
|  | } else if (len > CX82310_MTU) { | 
|  | netdev_err(dev->net, "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_cow_head(skb, 2)) { | 
|  | dev_kfree_skb_any(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"); |