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 int drvflags = 0; 77 78 /* altsetting should always be 1 for NCM devices - so we hard-coded 79 * it here. Some huawei devices will need the NDP part of the NCM package to 80 * be at the end of the frame. 81 */ 82 drvflags |= CDC_NCM_FLAG_NDP_TO_END; 83 ret = cdc_ncm_bind_common(usbnet_dev, intf, 1, drvflags); 84 if (ret) 85 goto err; 86 87 ctx = drvstate->ctx; 88 89 if (usbnet_dev->status) 90 /* The wMaxCommand buffer must be big enough to hold 91 * any message from the modem. Experience has shown 92 * that some replies are more than 256 bytes long 93 */ 94 subdriver = usb_cdc_wdm_register(ctx->control, 95 &usbnet_dev->status->desc, 96 1024, /* wMaxCommand */ 97 huawei_cdc_ncm_wdm_manage_power); 98 if (IS_ERR(subdriver)) { 99 ret = PTR_ERR(subdriver); 100 cdc_ncm_unbind(usbnet_dev, intf); 101 goto err; 102 } 103 104 /* Prevent usbnet from using the status descriptor */ 105 usbnet_dev->status = NULL; 106 107 drvstate->subdriver = subdriver; 108 109 err: 110 return ret; 111 } 112 113 static void huawei_cdc_ncm_unbind(struct usbnet *usbnet_dev, 114 struct usb_interface *intf) 115 { 116 struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data; 117 struct cdc_ncm_ctx *ctx = drvstate->ctx; 118 119 if (drvstate->subdriver && drvstate->subdriver->disconnect) 120 drvstate->subdriver->disconnect(ctx->control); 121 drvstate->subdriver = NULL; 122 123 cdc_ncm_unbind(usbnet_dev, intf); 124 } 125 126 static int huawei_cdc_ncm_suspend(struct usb_interface *intf, 127 pm_message_t message) 128 { 129 int ret = 0; 130 struct usbnet *usbnet_dev = usb_get_intfdata(intf); 131 struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data; 132 struct cdc_ncm_ctx *ctx = drvstate->ctx; 133 134 if (ctx == NULL) { 135 ret = -ENODEV; 136 goto error; 137 } 138 139 ret = usbnet_suspend(intf, message); 140 if (ret < 0) 141 goto error; 142 143 if (intf == ctx->control && 144 drvstate->subdriver && 145 drvstate->subdriver->suspend) 146 ret = drvstate->subdriver->suspend(intf, message); 147 if (ret < 0) 148 usbnet_resume(intf); 149 150 error: 151 return ret; 152 } 153 154 static int huawei_cdc_ncm_resume(struct usb_interface *intf) 155 { 156 int ret = 0; 157 struct usbnet *usbnet_dev = usb_get_intfdata(intf); 158 struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data; 159 bool callsub; 160 struct cdc_ncm_ctx *ctx = drvstate->ctx; 161 162 /* should we call subdriver's resume function? */ 163 callsub = 164 (intf == ctx->control && 165 drvstate->subdriver && 166 drvstate->subdriver->resume); 167 168 if (callsub) 169 ret = drvstate->subdriver->resume(intf); 170 if (ret < 0) 171 goto err; 172 ret = usbnet_resume(intf); 173 if (ret < 0 && callsub) 174 drvstate->subdriver->suspend(intf, PMSG_SUSPEND); 175 err: 176 return ret; 177 } 178 179 static const struct driver_info huawei_cdc_ncm_info = { 180 .description = "Huawei CDC NCM device", 181 .flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN, 182 .bind = huawei_cdc_ncm_bind, 183 .unbind = huawei_cdc_ncm_unbind, 184 .manage_power = huawei_cdc_ncm_manage_power, 185 .rx_fixup = cdc_ncm_rx_fixup, 186 .tx_fixup = cdc_ncm_tx_fixup, 187 }; 188 189 static const struct usb_device_id huawei_cdc_ncm_devs[] = { 190 /* Huawei NCM devices disguised as vendor specific */ 191 { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x16), 192 .driver_info = (unsigned long)&huawei_cdc_ncm_info, 193 }, 194 { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x46), 195 .driver_info = (unsigned long)&huawei_cdc_ncm_info, 196 }, 197 { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x76), 198 .driver_info = (unsigned long)&huawei_cdc_ncm_info, 199 }, 200 { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x03, 0x16), 201 .driver_info = (unsigned long)&huawei_cdc_ncm_info, 202 }, 203 204 /* Terminating entry */ 205 { 206 }, 207 }; 208 MODULE_DEVICE_TABLE(usb, huawei_cdc_ncm_devs); 209 210 static struct usb_driver huawei_cdc_ncm_driver = { 211 .name = "huawei_cdc_ncm", 212 .id_table = huawei_cdc_ncm_devs, 213 .probe = usbnet_probe, 214 .disconnect = usbnet_disconnect, 215 .suspend = huawei_cdc_ncm_suspend, 216 .resume = huawei_cdc_ncm_resume, 217 .reset_resume = huawei_cdc_ncm_resume, 218 .supports_autosuspend = 1, 219 .disable_hub_initiated_lpm = 1, 220 }; 221 module_usb_driver(huawei_cdc_ncm_driver); 222 MODULE_AUTHOR("Enrico Mioso <mrkiko.rs@gmail.com>"); 223 MODULE_DESCRIPTION("USB CDC NCM host driver with encapsulated protocol support"); 224 MODULE_LICENSE("GPL"); 225