kernel/drivers/net/usb/huawei_cdc_ncm.c

   1 /* huawei_cdc_ncm.c - handles Huawei devices using the CDC NCM protocol as
   2  * transport layer.
   3  * Copyright (C) 2013    Enrico Mioso <mrkiko.rs@gmail.com>
   4  *
   5  *
   6  * ABSTRACT:
   7  * This driver handles devices resembling the CDC NCM standard, but
   8  * encapsulating another protocol inside it. An example are some Huawei 3G
   9  * devices, exposing an embedded AT channel where you can set up the NCM
  10  * connection.
  11  * This code has been heavily inspired by the cdc_mbim.c driver, which is
  12  * Copyright (c) 2012  Smith Micro Software, Inc.
  13  * Copyright (c) 2012  Bjørn Mork <bjorn@mork.no>
  14  *
  15  * This program is free software; you can redistribute it and/or
  16  * modify it under the terms of the GNU General Public License
  17  * version 2 as published by the Free Software Foundation.
  18  */
  19
  20 #include <linux/module.h>
  21 #include <linux/netdevice.h>
  22 #include <linux/ethtool.h>
  23 #include <linux/if_vlan.h>
  24 #include <linux/ip.h>
  25 #include <linux/mii.h>
  26 #include <linux/usb.h>
  27 #include <linux/usb/cdc.h>
  28 #include <linux/usb/usbnet.h>
  29 #include <linux/usb/cdc-wdm.h>
  30 #include <linux/usb/cdc_ncm.h>
  31
  32 /* Driver data */
  33 struct huawei_cdc_ncm_state {
  34         struct cdc_ncm_ctx *ctx;
  35         atomic_t pmcount;
  36         struct usb_driver *subdriver;
  37         struct usb_interface *control;
  38         struct usb_interface *data;
  39 };
  40
  41 static int huawei_cdc_ncm_manage_power(struct usbnet *usbnet_dev, int on)
  42 {
  43         struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data;
  44         int rv;
  45
  46         if ((on && atomic_add_return(1, &drvstate->pmcount) == 1) ||
  47                         (!on && atomic_dec_and_test(&drvstate->pmcount))) {
  48                 rv = usb_autopm_get_interface(usbnet_dev->intf);
  49                 usbnet_dev->intf->needs_remote_wakeup = on;
  50                 if (!rv)
  51                         usb_autopm_put_interface(usbnet_dev->intf);
  52         }
  53         return 0;
  54 }
  55
  56 static int huawei_cdc_ncm_wdm_manage_power(struct usb_interface *intf,
  57                                            int status)
  58 {
  59         struct usbnet *usbnet_dev = usb_get_intfdata(intf);
  60
  61         /* can be called while disconnecting */
  62         if (!usbnet_dev)
  63                 return 0;
  64
  65         return huawei_cdc_ncm_manage_power(usbnet_dev, status);
  66 }
  67
  68
  69 static int huawei_cdc_ncm_bind(struct usbnet *usbnet_dev,
  70                                struct usb_interface *intf)
  71 {
  72         struct cdc_ncm_ctx *ctx;
  73         struct usb_driver *subdriver = ERR_PTR(-ENODEV);
  74         int ret = -ENODEV;
  75         struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data;
  76
  77         /* altsetting should always be 1 for NCM devices - so we hard-coded
  78          * it here
  79          */
  80         ret = cdc_ncm_bind_common(usbnet_dev, intf, 1);
  81         if (ret)
  82                 goto err;
  83
  84         ctx = drvstate->ctx;
  85
  86         if (usbnet_dev->status)
  87                 /* The wMaxCommand buffer must be big enough to hold
  88                  * any message from the modem. Experience has shown
  89                  * that some replies are more than 256 bytes long
  90                  */
  91                 subdriver = usb_cdc_wdm_register(ctx->control,
  92                                                  &usbnet_dev->status->desc,
  93                                                  1024, /* wMaxCommand */
  94                                                  huawei_cdc_ncm_wdm_manage_power);
  95         if (IS_ERR(subdriver)) {
  96                 ret = PTR_ERR(subdriver);
  97                 cdc_ncm_unbind(usbnet_dev, intf);
  98                 goto err;
  99         }
 100
 101         /* Prevent usbnet from using the status descriptor */
 102         usbnet_dev->status = NULL;
 103
 104         drvstate->subdriver = subdriver;
 105
 106 err:
 107         return ret;
 108 }
 109
 110 static void huawei_cdc_ncm_unbind(struct usbnet *usbnet_dev,
 111                                   struct usb_interface *intf)
 112 {
 113         struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data;
 114         struct cdc_ncm_ctx *ctx = drvstate->ctx;
 115
 116         if (drvstate->subdriver && drvstate->subdriver->disconnect)
 117                 drvstate->subdriver->disconnect(ctx->control);
 118         drvstate->subdriver = NULL;
 119
 120         cdc_ncm_unbind(usbnet_dev, intf);
 121 }
 122
 123 static int huawei_cdc_ncm_suspend(struct usb_interface *intf,
 124                                   pm_message_t message)
 125 {
 126         int ret = 0;
 127         struct usbnet *usbnet_dev = usb_get_intfdata(intf);
 128         struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data;
 129         struct cdc_ncm_ctx *ctx = drvstate->ctx;
 130
 131         if (ctx == NULL) {
 132                 ret = -ENODEV;
 133                 goto error;
 134         }
 135
 136         ret = usbnet_suspend(intf, message);
 137         if (ret < 0)
 138                 goto error;
 139
 140         if (intf == ctx->control &&
 141                 drvstate->subdriver &&
 142                 drvstate->subdriver->suspend)
 143                 ret = drvstate->subdriver->suspend(intf, message);
 144         if (ret < 0)
 145                 usbnet_resume(intf);
 146
 147 error:
 148         return ret;
 149 }
 150
 151 static int huawei_cdc_ncm_resume(struct usb_interface *intf)
 152 {
 153         int ret = 0;
 154         struct usbnet *usbnet_dev = usb_get_intfdata(intf);
 155         struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data;
 156         bool callsub;
 157         struct cdc_ncm_ctx *ctx = drvstate->ctx;
 158
 159         /* should we call subdriver's resume function? */
 160         callsub =
 161                 (intf == ctx->control &&
 162                 drvstate->subdriver &&
 163                 drvstate->subdriver->resume);
 164
 165         if (callsub)
 166                 ret = drvstate->subdriver->resume(intf);
 167         if (ret < 0)
 168                 goto err;
 169         ret = usbnet_resume(intf);
 170         if (ret < 0 && callsub)
 171                 drvstate->subdriver->suspend(intf, PMSG_SUSPEND);
 172 err:
 173         return ret;
 174 }
 175
 176 static const struct driver_info huawei_cdc_ncm_info = {
 177         .description = "Huawei CDC NCM device",
 178         .flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN,
 179         .bind = huawei_cdc_ncm_bind,
 180         .unbind = huawei_cdc_ncm_unbind,
 181         .manage_power = huawei_cdc_ncm_manage_power,
 182         .rx_fixup = cdc_ncm_rx_fixup,
 183         .tx_fixup = cdc_ncm_tx_fixup,
 184 };
 185
 186 static const struct usb_device_id huawei_cdc_ncm_devs[] = {
 187         /* Huawei NCM devices disguised as vendor specific */
 188         { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x16),
 189           .driver_info = (unsigned long)&huawei_cdc_ncm_info,
 190         },
 191         { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x46),
 192           .driver_info = (unsigned long)&huawei_cdc_ncm_info,
 193         },
 194         { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x76),
 195           .driver_info = (unsigned long)&huawei_cdc_ncm_info,
 196         },
 197         { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x03, 0x16),
 198           .driver_info = (unsigned long)&huawei_cdc_ncm_info,
 199         },
 200
 201         /* Terminating entry */
 202         {
 203         },
 204 };
 205 MODULE_DEVICE_TABLE(usb, huawei_cdc_ncm_devs);
 206
 207 static struct usb_driver huawei_cdc_ncm_driver = {
 208         .name = "huawei_cdc_ncm",
 209         .id_table = huawei_cdc_ncm_devs,
 210         .probe = usbnet_probe,
 211         .disconnect = usbnet_disconnect,
 212         .suspend = huawei_cdc_ncm_suspend,
 213         .resume = huawei_cdc_ncm_resume,
 214         .reset_resume = huawei_cdc_ncm_resume,
 215         .supports_autosuspend = 1,
 216         .disable_hub_initiated_lpm = 1,
 217 };
 218 module_usb_driver(huawei_cdc_ncm_driver);
 219 MODULE_AUTHOR("Enrico Mioso <mrkiko.rs@gmail.com>");
 220 MODULE_DESCRIPTION("USB CDC NCM host driver with encapsulated protocol support");
 221 MODULE_LICENSE("GPL");