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