1 /* 2 * f_serial.c - generic USB serial function driver 3 * 4 * Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com) 5 * Copyright (C) 2008 by David Brownell 6 * Copyright (C) 2008 by Nokia Corporation 7 * 8 * This software is distributed under the terms of the GNU General 9 * Public License ("GPL") as published by the Free Software Foundation, 10 * either version 2 of that License or (at your option) any later version. 11 */ 12 13 #include <linux/slab.h> 14 #include <linux/kernel.h> 15 #include <linux/module.h> 16 #include <linux/device.h> 17 18 #include "u_serial.h" 19 20 21 /* 22 * This function packages a simple "generic serial" port with no real 23 * control mechanisms, just raw data transfer over two bulk endpoints. 24 * 25 * Because it's not standardized, this isn't as interoperable as the 26 * CDC ACM driver. However, for many purposes it's just as functional 27 * if you can arrange appropriate host side drivers. 28 */ 29 30 struct f_gser { 31 struct gserial port; 32 u8 data_id; 33 u8 port_num; 34 }; 35 36 static inline struct f_gser *func_to_gser(struct usb_function *f) 37 { 38 return container_of(f, struct f_gser, port.func); 39 } 40 41 /*-------------------------------------------------------------------------*/ 42 43 /* interface descriptor: */ 44 45 static struct usb_interface_descriptor gser_interface_desc = { 46 .bLength = USB_DT_INTERFACE_SIZE, 47 .bDescriptorType = USB_DT_INTERFACE, 48 /* .bInterfaceNumber = DYNAMIC */ 49 .bNumEndpoints = 2, 50 .bInterfaceClass = USB_CLASS_VENDOR_SPEC, 51 .bInterfaceSubClass = 0, 52 .bInterfaceProtocol = 0, 53 /* .iInterface = DYNAMIC */ 54 }; 55 56 /* full speed support: */ 57 58 static struct usb_endpoint_descriptor gser_fs_in_desc = { 59 .bLength = USB_DT_ENDPOINT_SIZE, 60 .bDescriptorType = USB_DT_ENDPOINT, 61 .bEndpointAddress = USB_DIR_IN, 62 .bmAttributes = USB_ENDPOINT_XFER_BULK, 63 }; 64 65 static struct usb_endpoint_descriptor gser_fs_out_desc = { 66 .bLength = USB_DT_ENDPOINT_SIZE, 67 .bDescriptorType = USB_DT_ENDPOINT, 68 .bEndpointAddress = USB_DIR_OUT, 69 .bmAttributes = USB_ENDPOINT_XFER_BULK, 70 }; 71 72 static struct usb_descriptor_header *gser_fs_function[] = { 73 (struct usb_descriptor_header *) &gser_interface_desc, 74 (struct usb_descriptor_header *) &gser_fs_in_desc, 75 (struct usb_descriptor_header *) &gser_fs_out_desc, 76 NULL, 77 }; 78 79 /* high speed support: */ 80 81 static struct usb_endpoint_descriptor gser_hs_in_desc = { 82 .bLength = USB_DT_ENDPOINT_SIZE, 83 .bDescriptorType = USB_DT_ENDPOINT, 84 .bmAttributes = USB_ENDPOINT_XFER_BULK, 85 .wMaxPacketSize = cpu_to_le16(512), 86 }; 87 88 static struct usb_endpoint_descriptor gser_hs_out_desc = { 89 .bLength = USB_DT_ENDPOINT_SIZE, 90 .bDescriptorType = USB_DT_ENDPOINT, 91 .bmAttributes = USB_ENDPOINT_XFER_BULK, 92 .wMaxPacketSize = cpu_to_le16(512), 93 }; 94 95 static struct usb_descriptor_header *gser_hs_function[] = { 96 (struct usb_descriptor_header *) &gser_interface_desc, 97 (struct usb_descriptor_header *) &gser_hs_in_desc, 98 (struct usb_descriptor_header *) &gser_hs_out_desc, 99 NULL, 100 }; 101 102 static struct usb_endpoint_descriptor gser_ss_in_desc = { 103 .bLength = USB_DT_ENDPOINT_SIZE, 104 .bDescriptorType = USB_DT_ENDPOINT, 105 .bmAttributes = USB_ENDPOINT_XFER_BULK, 106 .wMaxPacketSize = cpu_to_le16(1024), 107 }; 108 109 static struct usb_endpoint_descriptor gser_ss_out_desc = { 110 .bLength = USB_DT_ENDPOINT_SIZE, 111 .bDescriptorType = USB_DT_ENDPOINT, 112 .bmAttributes = USB_ENDPOINT_XFER_BULK, 113 .wMaxPacketSize = cpu_to_le16(1024), 114 }; 115 116 static struct usb_ss_ep_comp_descriptor gser_ss_bulk_comp_desc = { 117 .bLength = sizeof gser_ss_bulk_comp_desc, 118 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP, 119 }; 120 121 static struct usb_descriptor_header *gser_ss_function[] = { 122 (struct usb_descriptor_header *) &gser_interface_desc, 123 (struct usb_descriptor_header *) &gser_ss_in_desc, 124 (struct usb_descriptor_header *) &gser_ss_bulk_comp_desc, 125 (struct usb_descriptor_header *) &gser_ss_out_desc, 126 (struct usb_descriptor_header *) &gser_ss_bulk_comp_desc, 127 NULL, 128 }; 129 130 /* string descriptors: */ 131 132 static struct usb_string gser_string_defs[] = { 133 [0].s = "Generic Serial", 134 { } /* end of list */ 135 }; 136 137 static struct usb_gadget_strings gser_string_table = { 138 .language = 0x0409, /* en-us */ 139 .strings = gser_string_defs, 140 }; 141 142 static struct usb_gadget_strings *gser_strings[] = { 143 &gser_string_table, 144 NULL, 145 }; 146 147 /*-------------------------------------------------------------------------*/ 148 149 static int gser_set_alt(struct usb_function *f, unsigned intf, unsigned alt) 150 { 151 struct f_gser *gser = func_to_gser(f); 152 struct usb_composite_dev *cdev = f->config->cdev; 153 154 /* we know alt == 0, so this is an activation or a reset */ 155 156 if (gser->port.in->driver_data) { 157 dev_dbg(&cdev->gadget->dev, 158 "reset generic ttyGS%d\n", gser->port_num); 159 gserial_disconnect(&gser->port); 160 } 161 if (!gser->port.in->desc || !gser->port.out->desc) { 162 dev_dbg(&cdev->gadget->dev, 163 "activate generic ttyGS%d\n", gser->port_num); 164 if (config_ep_by_speed(cdev->gadget, f, gser->port.in) || 165 config_ep_by_speed(cdev->gadget, f, gser->port.out)) { 166 gser->port.in->desc = NULL; 167 gser->port.out->desc = NULL; 168 return -EINVAL; 169 } 170 } 171 gserial_connect(&gser->port, gser->port_num); 172 return 0; 173 } 174 175 static void gser_disable(struct usb_function *f) 176 { 177 struct f_gser *gser = func_to_gser(f); 178 struct usb_composite_dev *cdev = f->config->cdev; 179 180 dev_dbg(&cdev->gadget->dev, 181 "generic ttyGS%d deactivated\n", gser->port_num); 182 gserial_disconnect(&gser->port); 183 } 184 185 /*-------------------------------------------------------------------------*/ 186 187 /* serial function driver setup/binding */ 188 189 static int gser_bind(struct usb_configuration *c, struct usb_function *f) 190 { 191 struct usb_composite_dev *cdev = c->cdev; 192 struct f_gser *gser = func_to_gser(f); 193 int status; 194 struct usb_ep *ep; 195 196 /* REVISIT might want instance-specific strings to help 197 * distinguish instances ... 198 */ 199 200 /* maybe allocate device-global string ID */ 201 if (gser_string_defs[0].id == 0) { 202 status = usb_string_id(c->cdev); 203 if (status < 0) 204 return status; 205 gser_string_defs[0].id = status; 206 } 207 208 /* allocate instance-specific interface IDs */ 209 status = usb_interface_id(c, f); 210 if (status < 0) 211 goto fail; 212 gser->data_id = status; 213 gser_interface_desc.bInterfaceNumber = status; 214 215 status = -ENODEV; 216 217 /* allocate instance-specific endpoints */ 218 ep = usb_ep_autoconfig(cdev->gadget, &gser_fs_in_desc); 219 if (!ep) 220 goto fail; 221 gser->port.in = ep; 222 ep->driver_data = cdev; /* claim */ 223 224 ep = usb_ep_autoconfig(cdev->gadget, &gser_fs_out_desc); 225 if (!ep) 226 goto fail; 227 gser->port.out = ep; 228 ep->driver_data = cdev; /* claim */ 229 230 /* support all relevant hardware speeds... we expect that when 231 * hardware is dual speed, all bulk-capable endpoints work at 232 * both speeds 233 */ 234 gser_hs_in_desc.bEndpointAddress = gser_fs_in_desc.bEndpointAddress; 235 gser_hs_out_desc.bEndpointAddress = gser_fs_out_desc.bEndpointAddress; 236 237 gser_ss_in_desc.bEndpointAddress = gser_fs_in_desc.bEndpointAddress; 238 gser_ss_out_desc.bEndpointAddress = gser_fs_out_desc.bEndpointAddress; 239 240 status = usb_assign_descriptors(f, gser_fs_function, gser_hs_function, 241 gser_ss_function); 242 if (status) 243 goto fail; 244 dev_dbg(&cdev->gadget->dev, "generic ttyGS%d: %s speed IN/%s OUT/%s\n", 245 gser->port_num, 246 gadget_is_superspeed(c->cdev->gadget) ? "super" : 247 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full", 248 gser->port.in->name, gser->port.out->name); 249 return 0; 250 251 fail: 252 /* we might as well release our claims on endpoints */ 253 if (gser->port.out) 254 gser->port.out->driver_data = NULL; 255 if (gser->port.in) 256 gser->port.in->driver_data = NULL; 257 258 ERROR(cdev, "%s: can't bind, err %d\n", f->name, status); 259 260 return status; 261 } 262 263 static inline struct f_serial_opts *to_f_serial_opts(struct config_item *item) 264 { 265 return container_of(to_config_group(item), struct f_serial_opts, 266 func_inst.group); 267 } 268 269 CONFIGFS_ATTR_STRUCT(f_serial_opts); 270 static ssize_t f_serial_attr_show(struct config_item *item, 271 struct configfs_attribute *attr, 272 char *page) 273 { 274 struct f_serial_opts *opts = to_f_serial_opts(item); 275 struct f_serial_opts_attribute *f_serial_opts_attr = 276 container_of(attr, struct f_serial_opts_attribute, attr); 277 ssize_t ret = 0; 278 279 if (f_serial_opts_attr->show) 280 ret = f_serial_opts_attr->show(opts, page); 281 282 return ret; 283 } 284 285 static void serial_attr_release(struct config_item *item) 286 { 287 struct f_serial_opts *opts = to_f_serial_opts(item); 288 289 usb_put_function_instance(&opts->func_inst); 290 } 291 292 static struct configfs_item_operations serial_item_ops = { 293 .release = serial_attr_release, 294 .show_attribute = f_serial_attr_show, 295 }; 296 297 static ssize_t f_serial_port_num_show(struct f_serial_opts *opts, char *page) 298 { 299 return sprintf(page, "%u\n", opts->port_num); 300 } 301 302 static struct f_serial_opts_attribute f_serial_port_num = 303 __CONFIGFS_ATTR_RO(port_num, f_serial_port_num_show); 304 305 static struct configfs_attribute *acm_attrs[] = { 306 &f_serial_port_num.attr, 307 NULL, 308 }; 309 310 static struct config_item_type serial_func_type = { 311 .ct_item_ops = &serial_item_ops, 312 .ct_attrs = acm_attrs, 313 .ct_owner = THIS_MODULE, 314 }; 315 316 static void gser_free_inst(struct usb_function_instance *f) 317 { 318 struct f_serial_opts *opts; 319 320 opts = container_of(f, struct f_serial_opts, func_inst); 321 gserial_free_line(opts->port_num); 322 kfree(opts); 323 } 324 325 static struct usb_function_instance *gser_alloc_inst(void) 326 { 327 struct f_serial_opts *opts; 328 int ret; 329 330 opts = kzalloc(sizeof(*opts), GFP_KERNEL); 331 if (!opts) 332 return ERR_PTR(-ENOMEM); 333 334 opts->func_inst.free_func_inst = gser_free_inst; 335 ret = gserial_alloc_line(&opts->port_num); 336 if (ret) { 337 kfree(opts); 338 return ERR_PTR(ret); 339 } 340 config_group_init_type_name(&opts->func_inst.group, "", 341 &serial_func_type); 342 343 return &opts->func_inst; 344 } 345 346 static void gser_free(struct usb_function *f) 347 { 348 struct f_gser *serial; 349 350 serial = func_to_gser(f); 351 kfree(serial); 352 } 353 354 static void gser_unbind(struct usb_configuration *c, struct usb_function *f) 355 { 356 usb_free_all_descriptors(f); 357 } 358 359 static struct usb_function *gser_alloc(struct usb_function_instance *fi) 360 { 361 struct f_gser *gser; 362 struct f_serial_opts *opts; 363 364 /* allocate and initialize one new instance */ 365 gser = kzalloc(sizeof(*gser), GFP_KERNEL); 366 if (!gser) 367 return ERR_PTR(-ENOMEM); 368 369 opts = container_of(fi, struct f_serial_opts, func_inst); 370 371 gser->port_num = opts->port_num; 372 373 gser->port.func.name = "gser"; 374 gser->port.func.strings = gser_strings; 375 gser->port.func.bind = gser_bind; 376 gser->port.func.unbind = gser_unbind; 377 gser->port.func.set_alt = gser_set_alt; 378 gser->port.func.disable = gser_disable; 379 gser->port.func.free_func = gser_free; 380 381 return &gser->port.func; 382 } 383 384 DECLARE_USB_FUNCTION_INIT(gser, gser_alloc_inst, gser_alloc); 385 MODULE_LICENSE("GPL"); 386 MODULE_AUTHOR("Al Borchers"); 387 MODULE_AUTHOR("David Brownell"); 388