Bjørn Mork | 423ce8c | 2012-01-19 15:37:22 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2012 Bjørn Mork <bjorn@mork.no> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License |
| 6 | * version 2 as published by the Free Software Foundation. |
| 7 | */ |
| 8 | |
| 9 | #include <linux/module.h> |
| 10 | #include <linux/netdevice.h> |
| 11 | #include <linux/ethtool.h> |
| 12 | #include <linux/mii.h> |
| 13 | #include <linux/usb.h> |
| 14 | #include <linux/usb/cdc.h> |
| 15 | #include <linux/usb/usbnet.h> |
Bjørn Mork | c3ecb08 | 2012-03-09 12:35:05 +0100 | [diff] [blame^] | 16 | #include <linux/usb/cdc-wdm.h> |
Bjørn Mork | 423ce8c | 2012-01-19 15:37:22 +0000 | [diff] [blame] | 17 | |
| 18 | /* The name of the CDC Device Management driver */ |
| 19 | #define DM_DRIVER "cdc_wdm" |
| 20 | |
| 21 | /* |
| 22 | * This driver supports wwan (3G/LTE/?) devices using a vendor |
| 23 | * specific management protocol called Qualcomm MSM Interface (QMI) - |
| 24 | * in addition to the more common AT commands over serial interface |
| 25 | * management |
| 26 | * |
| 27 | * QMI is wrapped in CDC, using CDC encapsulated commands on the |
| 28 | * control ("master") interface of a two-interface CDC Union |
| 29 | * resembling standard CDC ECM. The devices do not use the control |
| 30 | * interface for any other CDC messages. Most likely because the |
| 31 | * management protocol is used in place of the standard CDC |
| 32 | * notifications NOTIFY_NETWORK_CONNECTION and NOTIFY_SPEED_CHANGE |
| 33 | * |
| 34 | * Handling a protocol like QMI is out of the scope for any driver. |
| 35 | * It can be exported as a character device using the cdc-wdm driver, |
| 36 | * which will enable userspace applications ("modem managers") to |
| 37 | * handle it. This may be required to use the network interface |
| 38 | * provided by the driver. |
| 39 | * |
| 40 | * These devices may alternatively/additionally be configured using AT |
| 41 | * commands on any of the serial interfaces driven by the option driver |
| 42 | * |
| 43 | * This driver binds only to the data ("slave") interface to enable |
| 44 | * the cdc-wdm driver to bind to the control interface. It still |
| 45 | * parses the CDC functional descriptors on the control interface to |
| 46 | * a) verify that this is indeed a handled interface (CDC Union |
| 47 | * header lists it as slave) |
| 48 | * b) get MAC address and other ethernet config from the CDC Ethernet |
| 49 | * header |
| 50 | * c) enable user bind requests against the control interface, which |
| 51 | * is the common way to bind to CDC Ethernet Control Model type |
| 52 | * interfaces |
| 53 | * d) provide a hint to the user about which interface is the |
| 54 | * corresponding management interface |
| 55 | */ |
| 56 | |
| 57 | static int qmi_wwan_bind(struct usbnet *dev, struct usb_interface *intf) |
| 58 | { |
| 59 | int status = -1; |
| 60 | struct usb_interface *control = NULL; |
| 61 | u8 *buf = intf->cur_altsetting->extra; |
| 62 | int len = intf->cur_altsetting->extralen; |
| 63 | struct usb_interface_descriptor *desc = &intf->cur_altsetting->desc; |
| 64 | struct usb_cdc_union_desc *cdc_union = NULL; |
| 65 | struct usb_cdc_ether_desc *cdc_ether = NULL; |
| 66 | u32 required = 1 << USB_CDC_HEADER_TYPE | 1 << USB_CDC_UNION_TYPE; |
| 67 | u32 found = 0; |
Bjørn Mork | c3ecb08 | 2012-03-09 12:35:05 +0100 | [diff] [blame^] | 68 | atomic_t *pmcount = (void *)&dev->data[1]; |
| 69 | |
| 70 | atomic_set(pmcount, 0); |
Bjørn Mork | 423ce8c | 2012-01-19 15:37:22 +0000 | [diff] [blame] | 71 | |
| 72 | /* |
| 73 | * assume a data interface has no additional descriptors and |
| 74 | * that the control and data interface are numbered |
| 75 | * consecutively - this holds for the Huawei device at least |
| 76 | */ |
| 77 | if (len == 0 && desc->bInterfaceNumber > 0) { |
| 78 | control = usb_ifnum_to_if(dev->udev, desc->bInterfaceNumber - 1); |
| 79 | if (!control) |
| 80 | goto err; |
| 81 | |
| 82 | buf = control->cur_altsetting->extra; |
| 83 | len = control->cur_altsetting->extralen; |
| 84 | dev_dbg(&intf->dev, "guessing \"control\" => %s, \"data\" => this\n", |
| 85 | dev_name(&control->dev)); |
| 86 | } |
| 87 | |
| 88 | while (len > 3) { |
| 89 | struct usb_descriptor_header *h = (void *)buf; |
| 90 | |
| 91 | /* ignore any misplaced descriptors */ |
| 92 | if (h->bDescriptorType != USB_DT_CS_INTERFACE) |
| 93 | goto next_desc; |
| 94 | |
| 95 | /* buf[2] is CDC descriptor subtype */ |
| 96 | switch (buf[2]) { |
| 97 | case USB_CDC_HEADER_TYPE: |
| 98 | if (found & 1 << USB_CDC_HEADER_TYPE) { |
| 99 | dev_dbg(&intf->dev, "extra CDC header\n"); |
| 100 | goto err; |
| 101 | } |
| 102 | if (h->bLength != sizeof(struct usb_cdc_header_desc)) { |
| 103 | dev_dbg(&intf->dev, "CDC header len %u\n", h->bLength); |
| 104 | goto err; |
| 105 | } |
| 106 | break; |
| 107 | case USB_CDC_UNION_TYPE: |
| 108 | if (found & 1 << USB_CDC_UNION_TYPE) { |
| 109 | dev_dbg(&intf->dev, "extra CDC union\n"); |
| 110 | goto err; |
| 111 | } |
| 112 | if (h->bLength != sizeof(struct usb_cdc_union_desc)) { |
| 113 | dev_dbg(&intf->dev, "CDC union len %u\n", h->bLength); |
| 114 | goto err; |
| 115 | } |
| 116 | cdc_union = (struct usb_cdc_union_desc *)buf; |
| 117 | break; |
| 118 | case USB_CDC_ETHERNET_TYPE: |
| 119 | if (found & 1 << USB_CDC_ETHERNET_TYPE) { |
| 120 | dev_dbg(&intf->dev, "extra CDC ether\n"); |
| 121 | goto err; |
| 122 | } |
| 123 | if (h->bLength != sizeof(struct usb_cdc_ether_desc)) { |
| 124 | dev_dbg(&intf->dev, "CDC ether len %u\n", h->bLength); |
| 125 | goto err; |
| 126 | } |
| 127 | cdc_ether = (struct usb_cdc_ether_desc *)buf; |
| 128 | break; |
| 129 | } |
| 130 | |
| 131 | /* |
| 132 | * Remember which CDC functional descriptors we've seen. Works |
| 133 | * for all types we care about, of which USB_CDC_ETHERNET_TYPE |
| 134 | * (0x0f) is the highest numbered |
| 135 | */ |
| 136 | if (buf[2] < 32) |
| 137 | found |= 1 << buf[2]; |
| 138 | |
| 139 | next_desc: |
| 140 | len -= h->bLength; |
| 141 | buf += h->bLength; |
| 142 | } |
| 143 | |
| 144 | /* did we find all the required ones? */ |
| 145 | if ((found & required) != required) { |
| 146 | dev_err(&intf->dev, "CDC functional descriptors missing\n"); |
| 147 | goto err; |
| 148 | } |
| 149 | |
| 150 | /* give the user a helpful hint if trying to bind to the wrong interface */ |
| 151 | if (cdc_union && desc->bInterfaceNumber == cdc_union->bMasterInterface0) { |
| 152 | dev_err(&intf->dev, "leaving \"control\" interface for " DM_DRIVER " - try binding to %s instead!\n", |
| 153 | dev_name(&usb_ifnum_to_if(dev->udev, cdc_union->bSlaveInterface0)->dev)); |
| 154 | goto err; |
| 155 | } |
| 156 | |
| 157 | /* errors aren't fatal - we can live with the dynamic address */ |
| 158 | if (cdc_ether) { |
| 159 | dev->hard_mtu = le16_to_cpu(cdc_ether->wMaxSegmentSize); |
| 160 | usbnet_get_ethernet_addr(dev, cdc_ether->iMACAddress); |
| 161 | } |
| 162 | |
| 163 | /* success! point the user to the management interface */ |
| 164 | if (control) |
| 165 | dev_info(&intf->dev, "Use \"" DM_DRIVER "\" for QMI interface %s\n", |
| 166 | dev_name(&control->dev)); |
| 167 | |
| 168 | /* XXX: add a sysfs symlink somewhere to help management applications find it? */ |
| 169 | |
| 170 | /* collect bulk endpoints now that we know intf == "data" interface */ |
| 171 | status = usbnet_get_endpoints(dev, intf); |
| 172 | |
| 173 | err: |
| 174 | return status; |
| 175 | } |
| 176 | |
Bjørn Mork | c3ecb08 | 2012-03-09 12:35:05 +0100 | [diff] [blame^] | 177 | /* using a counter to merge subdriver requests with our own into a combined state */ |
Bjørn Mork | 423ce8c | 2012-01-19 15:37:22 +0000 | [diff] [blame] | 178 | static int qmi_wwan_manage_power(struct usbnet *dev, int on) |
| 179 | { |
Bjørn Mork | c3ecb08 | 2012-03-09 12:35:05 +0100 | [diff] [blame^] | 180 | atomic_t *pmcount = (void *)&dev->data[1]; |
| 181 | int rv = 0; |
| 182 | |
| 183 | dev_dbg(&dev->intf->dev, "%s() pmcount=%d, on=%d\n", __func__, atomic_read(pmcount), on); |
| 184 | |
| 185 | if ((on && atomic_add_return(1, pmcount) == 1) || (!on && atomic_dec_and_test(pmcount))) { |
| 186 | /* need autopm_get/put here to ensure the usbcore sees the new value */ |
| 187 | rv = usb_autopm_get_interface(dev->intf); |
| 188 | if (rv < 0) |
| 189 | goto err; |
| 190 | dev->intf->needs_remote_wakeup = on; |
| 191 | usb_autopm_put_interface(dev->intf); |
| 192 | } |
| 193 | err: |
| 194 | return rv; |
Bjørn Mork | 423ce8c | 2012-01-19 15:37:22 +0000 | [diff] [blame] | 195 | } |
| 196 | |
Bjørn Mork | c3ecb08 | 2012-03-09 12:35:05 +0100 | [diff] [blame^] | 197 | static int qmi_wwan_cdc_wdm_manage_power(struct usb_interface *intf, int on) |
| 198 | { |
| 199 | struct usbnet *dev = usb_get_intfdata(intf); |
| 200 | return qmi_wwan_manage_power(dev, on); |
| 201 | } |
| 202 | |
| 203 | /* Some devices combine the "control" and "data" functions into a |
| 204 | * single interface with all three endpoints: interrupt + bulk in and |
| 205 | * out |
| 206 | * |
| 207 | * Setting up cdc-wdm as a subdriver owning the interrupt endpoint |
| 208 | * will let it provide userspace access to the encapsulated QMI |
| 209 | * protocol without interfering with the usbnet operations. |
| 210 | */ |
| 211 | static int qmi_wwan_bind_shared(struct usbnet *dev, struct usb_interface *intf) |
| 212 | { |
| 213 | int rv; |
| 214 | struct usb_driver *subdriver = NULL; |
| 215 | atomic_t *pmcount = (void *)&dev->data[1]; |
| 216 | |
| 217 | atomic_set(pmcount, 0); |
| 218 | |
| 219 | /* collect all three endpoints */ |
| 220 | rv = usbnet_get_endpoints(dev, intf); |
| 221 | if (rv < 0) |
| 222 | goto err; |
| 223 | |
| 224 | /* require interrupt endpoint for subdriver */ |
| 225 | if (!dev->status) { |
| 226 | rv = -EINVAL; |
| 227 | goto err; |
| 228 | } |
| 229 | |
| 230 | subdriver = usb_cdc_wdm_register(intf, &dev->status->desc, 512, &qmi_wwan_cdc_wdm_manage_power); |
| 231 | if (IS_ERR(subdriver)) { |
| 232 | rv = PTR_ERR(subdriver); |
| 233 | goto err; |
| 234 | } |
| 235 | |
| 236 | /* can't let usbnet use the interrupt endpoint */ |
| 237 | dev->status = NULL; |
| 238 | |
| 239 | /* save subdriver struct for suspend/resume wrappers */ |
| 240 | dev->data[0] = (unsigned long)subdriver; |
| 241 | |
| 242 | err: |
| 243 | return rv; |
| 244 | } |
| 245 | |
| 246 | static void qmi_wwan_unbind_shared(struct usbnet *dev, struct usb_interface *intf) |
| 247 | { |
| 248 | struct usb_driver *subdriver = (void *)dev->data[0]; |
| 249 | |
| 250 | if (subdriver && subdriver->disconnect) |
| 251 | subdriver->disconnect(intf); |
| 252 | |
| 253 | dev->data[0] = (unsigned long)NULL; |
| 254 | } |
| 255 | |
| 256 | /* suspend/resume wrappers calling both usbnet and the cdc-wdm |
| 257 | * subdriver if present. |
| 258 | * |
| 259 | * NOTE: cdc-wdm also supports pre/post_reset, but we cannot provide |
| 260 | * wrappers for those without adding usbnet reset support first. |
| 261 | */ |
| 262 | static int qmi_wwan_suspend(struct usb_interface *intf, pm_message_t message) |
| 263 | { |
| 264 | struct usbnet *dev = usb_get_intfdata(intf); |
| 265 | struct usb_driver *subdriver = (void *)dev->data[0]; |
| 266 | int ret; |
| 267 | |
| 268 | ret = usbnet_suspend(intf, message); |
| 269 | if (ret < 0) |
| 270 | goto err; |
| 271 | |
| 272 | if (subdriver && subdriver->suspend) |
| 273 | ret = subdriver->suspend(intf, message); |
| 274 | if (ret < 0) |
| 275 | usbnet_resume(intf); |
| 276 | err: |
| 277 | return ret; |
| 278 | } |
| 279 | |
| 280 | static int qmi_wwan_resume(struct usb_interface *intf) |
| 281 | { |
| 282 | struct usbnet *dev = usb_get_intfdata(intf); |
| 283 | struct usb_driver *subdriver = (void *)dev->data[0]; |
| 284 | int ret = 0; |
| 285 | |
| 286 | if (subdriver && subdriver->resume) |
| 287 | ret = subdriver->resume(intf); |
| 288 | if (ret < 0) |
| 289 | goto err; |
| 290 | ret = usbnet_resume(intf); |
| 291 | if (ret < 0 && subdriver && subdriver->resume && subdriver->suspend) |
| 292 | subdriver->suspend(intf, PMSG_SUSPEND); |
| 293 | err: |
| 294 | return ret; |
| 295 | } |
| 296 | |
| 297 | |
Bjørn Mork | 423ce8c | 2012-01-19 15:37:22 +0000 | [diff] [blame] | 298 | static const struct driver_info qmi_wwan_info = { |
| 299 | .description = "QMI speaking wwan device", |
| 300 | .flags = FLAG_WWAN, |
| 301 | .bind = qmi_wwan_bind, |
| 302 | .manage_power = qmi_wwan_manage_power, |
| 303 | }; |
| 304 | |
Bjørn Mork | c3ecb08 | 2012-03-09 12:35:05 +0100 | [diff] [blame^] | 305 | static const struct driver_info qmi_wwan_shared = { |
| 306 | .description = "QMI speaking wwan device with combined interface", |
| 307 | .flags = FLAG_WWAN, |
| 308 | .bind = qmi_wwan_bind_shared, |
| 309 | .unbind = qmi_wwan_unbind_shared, |
| 310 | .manage_power = qmi_wwan_manage_power, |
| 311 | }; |
| 312 | |
Bjørn Mork | 423ce8c | 2012-01-19 15:37:22 +0000 | [diff] [blame] | 313 | #define HUAWEI_VENDOR_ID 0x12D1 |
| 314 | |
| 315 | static const struct usb_device_id products[] = { |
Bjørn Mork | c3ecb08 | 2012-03-09 12:35:05 +0100 | [diff] [blame^] | 316 | { /* Huawei E392, E398 and possibly others sharing both device id and more... */ |
| 317 | .match_flags = USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_INT_INFO, |
| 318 | .idVendor = HUAWEI_VENDOR_ID, |
| 319 | .bInterfaceClass = USB_CLASS_VENDOR_SPEC, |
| 320 | .bInterfaceSubClass = 1, |
| 321 | .bInterfaceProtocol = 8, /* NOTE: This is the *slave* interface of the CDC Union! */ |
| 322 | .driver_info = (unsigned long)&qmi_wwan_info, |
| 323 | }, |
| 324 | { /* Huawei E392, E398 and possibly others in "Windows mode" |
| 325 | * using a combined control and data interface without any CDC |
| 326 | * functional descriptors |
| 327 | */ |
| 328 | .match_flags = USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_INT_INFO, |
| 329 | .idVendor = HUAWEI_VENDOR_ID, |
| 330 | .bInterfaceClass = USB_CLASS_VENDOR_SPEC, |
| 331 | .bInterfaceSubClass = 1, |
| 332 | .bInterfaceProtocol = 17, |
| 333 | .driver_info = (unsigned long)&qmi_wwan_shared, |
| 334 | }, |
| 335 | { } /* END */ |
Bjørn Mork | 423ce8c | 2012-01-19 15:37:22 +0000 | [diff] [blame] | 336 | }; |
| 337 | MODULE_DEVICE_TABLE(usb, products); |
| 338 | |
| 339 | static struct usb_driver qmi_wwan_driver = { |
| 340 | .name = "qmi_wwan", |
| 341 | .id_table = products, |
| 342 | .probe = usbnet_probe, |
| 343 | .disconnect = usbnet_disconnect, |
Bjørn Mork | c3ecb08 | 2012-03-09 12:35:05 +0100 | [diff] [blame^] | 344 | .suspend = qmi_wwan_suspend, |
| 345 | .resume = qmi_wwan_resume, |
| 346 | .reset_resume = qmi_wwan_resume, |
Bjørn Mork | 423ce8c | 2012-01-19 15:37:22 +0000 | [diff] [blame] | 347 | .supports_autosuspend = 1, |
| 348 | }; |
| 349 | |
| 350 | static int __init qmi_wwan_init(void) |
| 351 | { |
| 352 | return usb_register(&qmi_wwan_driver); |
| 353 | } |
| 354 | module_init(qmi_wwan_init); |
| 355 | |
| 356 | static void __exit qmi_wwan_exit(void) |
| 357 | { |
| 358 | usb_deregister(&qmi_wwan_driver); |
| 359 | } |
| 360 | module_exit(qmi_wwan_exit); |
| 361 | |
| 362 | MODULE_AUTHOR("Bjørn Mork <bjorn@mork.no>"); |
| 363 | MODULE_DESCRIPTION("Qualcomm MSM Interface (QMI) WWAN driver"); |
| 364 | MODULE_LICENSE("GPL"); |