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 /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 88 * decimal (0x100)" 89 */ 90 subdriver = usb_cdc_wdm_register(ctx->control, 91 &usbnet_dev->status->desc, 92 256, /* wMaxCommand */ 93 huawei_cdc_ncm_wdm_manage_power); 94 if (IS_ERR(subdriver)) { 95 ret = PTR_ERR(subdriver); 96 cdc_ncm_unbind(usbnet_dev, intf); 97 goto err; 98 } 99 100 /* Prevent usbnet from using the status descriptor */ 101 usbnet_dev->status = NULL; 102 103 drvstate->subdriver = subdriver; 104 105 err: 106 return ret; 107 } 108 109 static void huawei_cdc_ncm_unbind(struct usbnet *usbnet_dev, 110 struct usb_interface *intf) 111 { 112 struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data; 113 struct cdc_ncm_ctx *ctx = drvstate->ctx; 114 115 if (drvstate->subdriver && drvstate->subdriver->disconnect) 116 drvstate->subdriver->disconnect(ctx->control); 117 drvstate->subdriver = NULL; 118 119 cdc_ncm_unbind(usbnet_dev, intf); 120 } 121 122 static int huawei_cdc_ncm_suspend(struct usb_interface *intf, 123 pm_message_t message) 124 { 125 int ret = 0; 126 struct usbnet *usbnet_dev = usb_get_intfdata(intf); 127 struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data; 128 struct cdc_ncm_ctx *ctx = drvstate->ctx; 129 130 if (ctx == NULL) { 131 ret = -ENODEV; 132 goto error; 133 } 134 135 ret = usbnet_suspend(intf, message); 136 if (ret < 0) 137 goto error; 138 139 if (intf == ctx->control && 140 drvstate->subdriver && 141 drvstate->subdriver->suspend) 142 ret = drvstate->subdriver->suspend(intf, message); 143 if (ret < 0) 144 usbnet_resume(intf); 145 146 error: 147 return ret; 148 } 149 150 static int huawei_cdc_ncm_resume(struct usb_interface *intf) 151 { 152 int ret = 0; 153 struct usbnet *usbnet_dev = usb_get_intfdata(intf); 154 struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data; 155 bool callsub; 156 struct cdc_ncm_ctx *ctx = drvstate->ctx; 157 158 /* should we call subdriver's resume function? */ 159 callsub = 160 (intf == ctx->control && 161 drvstate->subdriver && 162 drvstate->subdriver->resume); 163 164 if (callsub) 165 ret = drvstate->subdriver->resume(intf); 166 if (ret < 0) 167 goto err; 168 ret = usbnet_resume(intf); 169 if (ret < 0 && callsub) 170 drvstate->subdriver->suspend(intf, PMSG_SUSPEND); 171 err: 172 return ret; 173 } 174 175 static int huawei_cdc_ncm_check_connect(struct usbnet *usbnet_dev) 176 { 177 struct cdc_ncm_ctx *ctx; 178 179 ctx = (struct cdc_ncm_ctx *)usbnet_dev->data[0]; 180 181 if (ctx == NULL) 182 return 1; /* disconnected */ 183 184 return !ctx->connected; 185 } 186 187 static const struct driver_info huawei_cdc_ncm_info = { 188 .description = "Huawei CDC NCM device", 189 .flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN, 190 .bind = huawei_cdc_ncm_bind, 191 .unbind = huawei_cdc_ncm_unbind, 192 .check_connect = huawei_cdc_ncm_check_connect, 193 .manage_power = huawei_cdc_ncm_manage_power, 194 .rx_fixup = cdc_ncm_rx_fixup, 195 .tx_fixup = cdc_ncm_tx_fixup, 196 }; 197 198 static const struct usb_device_id huawei_cdc_ncm_devs[] = { 199 /* Huawei NCM devices disguised as vendor specific */ 200 { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x16), 201 .driver_info = (unsigned long)&huawei_cdc_ncm_info, 202 }, 203 { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x46), 204 .driver_info = (unsigned long)&huawei_cdc_ncm_info, 205 }, 206 { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x76), 207 .driver_info = (unsigned long)&huawei_cdc_ncm_info, 208 }, 209 210 /* Terminating entry */ 211 { 212 }, 213 }; 214 MODULE_DEVICE_TABLE(usb, huawei_cdc_ncm_devs); 215 216 static struct usb_driver huawei_cdc_ncm_driver = { 217 .name = "huawei_cdc_ncm", 218 .id_table = huawei_cdc_ncm_devs, 219 .probe = usbnet_probe, 220 .disconnect = usbnet_disconnect, 221 .suspend = huawei_cdc_ncm_suspend, 222 .resume = huawei_cdc_ncm_resume, 223 .reset_resume = huawei_cdc_ncm_resume, 224 .supports_autosuspend = 1, 225 .disable_hub_initiated_lpm = 1, 226 }; 227 module_usb_driver(huawei_cdc_ncm_driver); 228 MODULE_AUTHOR("Enrico Mioso <mrkiko.rs@gmail.com>"); 229 MODULE_DESCRIPTION("USB CDC NCM host driver with encapsulated protocol support"); 230 MODULE_LICENSE("GPL"); 231