drivers/net/usb/huawei_cdc_ncm.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* huawei_cdc_ncm.c - handles Huawei devices using the CDC NCM protocol as
   3  * transport layer.
   4  * Copyright (C) 2013    Enrico Mioso <mrkiko.rs@gmail.com>
   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
  16 #include <linux/module.h>
  17 #include <linux/netdevice.h>
  18 #include <linux/ethtool.h>
  19 #include <linux/if_vlan.h>
  20 #include <linux/ip.h>
  21 #include <linux/mii.h>
  22 #include <linux/usb.h>
  23 #include <linux/usb/cdc.h>
  24 #include <linux/usb/usbnet.h>
  25 #include <linux/usb/cdc-wdm.h>
  26 #include <linux/usb/cdc_ncm.h>
  27
  28 /* Driver data */
  29 struct huawei_cdc_ncm_state {
  30         struct cdc_ncm_ctx *ctx;
  31         atomic_t pmcount;
  32         struct usb_driver *subdriver;
  33         struct usb_interface *control;
  34         struct usb_interface *data;
  35 };
  36
  37 static int huawei_cdc_ncm_manage_power(struct usbnet *usbnet_dev, int on)
  38 {
  39         struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data;
  40         int rv;
  41
  42         if ((on && atomic_add_return(1, &drvstate->pmcount) == 1) ||
  43                         (!on && atomic_dec_and_test(&drvstate->pmcount))) {
  44                 rv = usb_autopm_get_interface(usbnet_dev->intf);
  45                 usbnet_dev->intf->needs_remote_wakeup = on;
  46                 if (!rv)
  47                         usb_autopm_put_interface(usbnet_dev->intf);
  48         }
  49         return 0;
  50 }
  51
  52 static int huawei_cdc_ncm_wdm_manage_power(struct usb_interface *intf,
  53                                            int status)
  54 {
  55         struct usbnet *usbnet_dev = usb_get_intfdata(intf);
  56
  57         /* can be called while disconnecting */
  58         if (!usbnet_dev)
  59                 return 0;
  60
  61         return huawei_cdc_ncm_manage_power(usbnet_dev, status);
  62 }
  63
  64
  65 static int huawei_cdc_ncm_bind(struct usbnet *usbnet_dev,
  66                                struct usb_interface *intf)
  67 {
  68         struct cdc_ncm_ctx *ctx;
  69         struct usb_driver *subdriver = ERR_PTR(-ENODEV);
  70         int ret;
  71         struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data;
  72         int drvflags = 0;
  73
  74         /* altsetting should always be 1 for NCM devices - so we hard-coded
  75          * it here. Some huawei devices will need the NDP part of the NCM package to
  76          * be at the end of the frame.
  77          */
  78         drvflags |= CDC_NCM_FLAG_NDP_TO_END;
  79
  80         /* For many Huawei devices the NTB32 mode is the default and the best mode
  81          * they work with. Huawei E5785 and E5885 devices refuse to work in NTB16 mode at all.
  82          */
  83         drvflags |= CDC_NCM_FLAG_PREFER_NTB32;
  84
  85         ret = cdc_ncm_bind_common(usbnet_dev, intf, 1, drvflags);
  86         if (ret)
  87                 goto err;
  88
  89         ctx = drvstate->ctx;
  90
  91         if (usbnet_dev->status)
  92                 /* The wMaxCommand buffer must be big enough to hold
  93                  * any message from the modem. Experience has shown
  94                  * that some replies are more than 256 bytes long
  95                  */
  96                 subdriver = usb_cdc_wdm_register(ctx->control,
  97                                                  &usbnet_dev->status->desc,
  98                                                  1024, /* wMaxCommand */
  99                                                  WWAN_PORT_AT,
 100                                                  huawei_cdc_ncm_wdm_manage_power);
 101         if (IS_ERR(subdriver)) {
 102                 ret = PTR_ERR(subdriver);
 103                 cdc_ncm_unbind(usbnet_dev, intf);
 104                 goto err;
 105         }
 106
 107         /* Prevent usbnet from using the status descriptor */
 108         usbnet_dev->status = NULL;
 109
 110         drvstate->subdriver = subdriver;
 111
 112 err:
 113         return ret;
 114 }
 115
 116 static void huawei_cdc_ncm_unbind(struct usbnet *usbnet_dev,
 117                                   struct usb_interface *intf)
 118 {
 119         struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data;
 120         struct cdc_ncm_ctx *ctx = drvstate->ctx;
 121
 122         if (drvstate->subdriver && drvstate->subdriver->disconnect)
 123                 drvstate->subdriver->disconnect(ctx->control);
 124         drvstate->subdriver = NULL;
 125
 126         cdc_ncm_unbind(usbnet_dev, intf);
 127 }
 128
 129 static int huawei_cdc_ncm_suspend(struct usb_interface *intf,
 130                                   pm_message_t message)
 131 {
 132         int ret = 0;
 133         struct usbnet *usbnet_dev = usb_get_intfdata(intf);
 134         struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data;
 135         struct cdc_ncm_ctx *ctx = drvstate->ctx;
 136
 137         if (ctx == NULL) {
 138                 ret = -ENODEV;
 139                 goto error;
 140         }
 141
 142         ret = usbnet_suspend(intf, message);
 143         if (ret < 0)
 144                 goto error;
 145
 146         if (intf == ctx->control &&
 147                 drvstate->subdriver &&
 148                 drvstate->subdriver->suspend)
 149                 ret = drvstate->subdriver->suspend(intf, message);
 150         if (ret < 0)
 151                 usbnet_resume(intf);
 152
 153 error:
 154         return ret;
 155 }
 156
 157 static int huawei_cdc_ncm_resume(struct usb_interface *intf)
 158 {
 159         int ret = 0;
 160         struct usbnet *usbnet_dev = usb_get_intfdata(intf);
 161         struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data;
 162         bool callsub;
 163         struct cdc_ncm_ctx *ctx = drvstate->ctx;
 164
 165         /* should we call subdriver's resume function? */
 166         callsub =
 167                 (intf == ctx->control &&
 168                 drvstate->subdriver &&
 169                 drvstate->subdriver->resume);
 170
 171         if (callsub)
 172                 ret = drvstate->subdriver->resume(intf);
 173         if (ret < 0)
 174                 goto err;
 175         ret = usbnet_resume(intf);
 176         if (ret < 0 && callsub)
 177                 drvstate->subdriver->suspend(intf, PMSG_SUSPEND);
 178 err:
 179         return ret;
 180 }
 181
 182 static const struct driver_info huawei_cdc_ncm_info = {
 183         .description = "Huawei CDC NCM device",
 184         .flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN,
 185         .bind = huawei_cdc_ncm_bind,
 186         .unbind = huawei_cdc_ncm_unbind,
 187         .manage_power = huawei_cdc_ncm_manage_power,
 188         .rx_fixup = cdc_ncm_rx_fixup,
 189         .tx_fixup = cdc_ncm_tx_fixup,
 190 };
 191
 192 static const struct usb_device_id huawei_cdc_ncm_devs[] = {
 193         /* Huawei NCM devices disguised as vendor specific */
 194         { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x16),
 195           .driver_info = (unsigned long)&huawei_cdc_ncm_info,
 196         },
 197         { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x46),
 198           .driver_info = (unsigned long)&huawei_cdc_ncm_info,
 199         },
 200         { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x76),
 201           .driver_info = (unsigned long)&huawei_cdc_ncm_info,
 202         },
 203         { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x03, 0x16),
 204           .driver_info = (unsigned long)&huawei_cdc_ncm_info,
 205         },
 206
 207         /* Terminating entry */
 208         {
 209         },
 210 };
 211 MODULE_DEVICE_TABLE(usb, huawei_cdc_ncm_devs);
 212
 213 static struct usb_driver huawei_cdc_ncm_driver = {
 214         .name = "huawei_cdc_ncm",
 215         .id_table = huawei_cdc_ncm_devs,
 216         .probe = usbnet_probe,
 217         .disconnect = usbnet_disconnect,
 218         .suspend = huawei_cdc_ncm_suspend,
 219         .resume = huawei_cdc_ncm_resume,
 220         .reset_resume = huawei_cdc_ncm_resume,
 221         .supports_autosuspend = 1,
 222         .disable_hub_initiated_lpm = 1,
 223 };
 224 module_usb_driver(huawei_cdc_ncm_driver);
 225 MODULE_AUTHOR("Enrico Mioso <mrkiko.rs@gmail.com>");
 226 MODULE_DESCRIPTION("USB CDC NCM host driver with encapsulated protocol support");
 227 MODULE_LICENSE("GPL");