1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * serial.c -- USB gadget serial driver 4 * 5 * Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com) 6 * Copyright (C) 2008 by David Brownell 7 * Copyright (C) 2008 by Nokia Corporation 8 */ 9 10 #include <linux/kernel.h> 11 #include <linux/device.h> 12 #include <linux/module.h> 13 #include <linux/tty.h> 14 #include <linux/tty_flip.h> 15 16 #include "u_serial.h" 17 18 19 /* Defines */ 20 21 #define GS_VERSION_STR "v2.4" 22 #define GS_VERSION_NUM 0x2400 23 24 #define GS_LONG_NAME "Gadget Serial" 25 #define GS_VERSION_NAME GS_LONG_NAME " " GS_VERSION_STR 26 27 /*-------------------------------------------------------------------------*/ 28 USB_GADGET_COMPOSITE_OPTIONS(); 29 30 /* Thanks to NetChip Technologies for donating this product ID. 31 * 32 * DO NOT REUSE THESE IDs with a protocol-incompatible driver!! Ever!! 33 * Instead: allocate your own, using normal USB-IF procedures. 34 */ 35 #define GS_VENDOR_ID 0x0525 /* NetChip */ 36 #define GS_PRODUCT_ID 0xa4a6 /* Linux-USB Serial Gadget */ 37 #define GS_CDC_PRODUCT_ID 0xa4a7 /* ... as CDC-ACM */ 38 #define GS_CDC_OBEX_PRODUCT_ID 0xa4a9 /* ... as CDC-OBEX */ 39 40 /* string IDs are assigned dynamically */ 41 42 #define STRING_DESCRIPTION_IDX USB_GADGET_FIRST_AVAIL_IDX 43 44 static struct usb_string strings_dev[] = { 45 [USB_GADGET_MANUFACTURER_IDX].s = "", 46 [USB_GADGET_PRODUCT_IDX].s = GS_VERSION_NAME, 47 [USB_GADGET_SERIAL_IDX].s = "", 48 [STRING_DESCRIPTION_IDX].s = NULL /* updated; f(use_acm) */, 49 { } /* end of list */ 50 }; 51 52 static struct usb_gadget_strings stringtab_dev = { 53 .language = 0x0409, /* en-us */ 54 .strings = strings_dev, 55 }; 56 57 static struct usb_gadget_strings *dev_strings[] = { 58 &stringtab_dev, 59 NULL, 60 }; 61 62 static struct usb_device_descriptor device_desc = { 63 .bLength = USB_DT_DEVICE_SIZE, 64 .bDescriptorType = USB_DT_DEVICE, 65 /* .bcdUSB = DYNAMIC */ 66 /* .bDeviceClass = f(use_acm) */ 67 .bDeviceSubClass = 0, 68 .bDeviceProtocol = 0, 69 /* .bMaxPacketSize0 = f(hardware) */ 70 .idVendor = cpu_to_le16(GS_VENDOR_ID), 71 /* .idProduct = f(use_acm) */ 72 .bcdDevice = cpu_to_le16(GS_VERSION_NUM), 73 /* .iManufacturer = DYNAMIC */ 74 /* .iProduct = DYNAMIC */ 75 .bNumConfigurations = 1, 76 }; 77 78 static const struct usb_descriptor_header *otg_desc[2]; 79 80 /*-------------------------------------------------------------------------*/ 81 82 /* Module */ 83 MODULE_DESCRIPTION(GS_VERSION_NAME); 84 MODULE_AUTHOR("Al Borchers"); 85 MODULE_AUTHOR("David Brownell"); 86 MODULE_LICENSE("GPL"); 87 88 static bool use_acm = true; 89 module_param(use_acm, bool, 0); 90 MODULE_PARM_DESC(use_acm, "Use CDC ACM, default=yes"); 91 92 static bool use_obex = false; 93 module_param(use_obex, bool, 0); 94 MODULE_PARM_DESC(use_obex, "Use CDC OBEX, default=no"); 95 96 static unsigned n_ports = 1; 97 module_param(n_ports, uint, 0); 98 MODULE_PARM_DESC(n_ports, "number of ports to create, default=1"); 99 100 static bool enable = true; 101 102 static int switch_gserial_enable(bool do_enable); 103 104 static int enable_set(const char *s, const struct kernel_param *kp) 105 { 106 bool do_enable; 107 int ret; 108 109 if (!s) /* called for no-arg enable == default */ 110 return 0; 111 112 ret = strtobool(s, &do_enable); 113 if (ret || enable == do_enable) 114 return ret; 115 116 ret = switch_gserial_enable(do_enable); 117 if (!ret) 118 enable = do_enable; 119 120 return ret; 121 } 122 123 static const struct kernel_param_ops enable_ops = { 124 .set = enable_set, 125 .get = param_get_bool, 126 }; 127 128 module_param_cb(enable, &enable_ops, &enable, 0644); 129 130 /*-------------------------------------------------------------------------*/ 131 132 static struct usb_configuration serial_config_driver = { 133 /* .label = f(use_acm) */ 134 /* .bConfigurationValue = f(use_acm) */ 135 /* .iConfiguration = DYNAMIC */ 136 .bmAttributes = USB_CONFIG_ATT_SELFPOWER, 137 }; 138 139 static struct usb_function_instance *fi_serial[MAX_U_SERIAL_PORTS]; 140 static struct usb_function *f_serial[MAX_U_SERIAL_PORTS]; 141 142 static int serial_register_ports(struct usb_composite_dev *cdev, 143 struct usb_configuration *c, const char *f_name) 144 { 145 int i; 146 int ret; 147 148 ret = usb_add_config_only(cdev, c); 149 if (ret) 150 goto out; 151 152 for (i = 0; i < n_ports; i++) { 153 154 fi_serial[i] = usb_get_function_instance(f_name); 155 if (IS_ERR(fi_serial[i])) { 156 ret = PTR_ERR(fi_serial[i]); 157 goto fail; 158 } 159 160 f_serial[i] = usb_get_function(fi_serial[i]); 161 if (IS_ERR(f_serial[i])) { 162 ret = PTR_ERR(f_serial[i]); 163 goto err_get_func; 164 } 165 166 ret = usb_add_function(c, f_serial[i]); 167 if (ret) 168 goto err_add_func; 169 } 170 171 return 0; 172 173 err_add_func: 174 usb_put_function(f_serial[i]); 175 err_get_func: 176 usb_put_function_instance(fi_serial[i]); 177 178 fail: 179 i--; 180 while (i >= 0) { 181 usb_remove_function(c, f_serial[i]); 182 usb_put_function(f_serial[i]); 183 usb_put_function_instance(fi_serial[i]); 184 i--; 185 } 186 out: 187 return ret; 188 } 189 190 static int gs_bind(struct usb_composite_dev *cdev) 191 { 192 int status; 193 194 /* Allocate string descriptor numbers ... note that string 195 * contents can be overridden by the composite_dev glue. 196 */ 197 198 status = usb_string_ids_tab(cdev, strings_dev); 199 if (status < 0) 200 goto fail; 201 device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id; 202 device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id; 203 status = strings_dev[STRING_DESCRIPTION_IDX].id; 204 serial_config_driver.iConfiguration = status; 205 206 if (gadget_is_otg(cdev->gadget)) { 207 if (!otg_desc[0]) { 208 struct usb_descriptor_header *usb_desc; 209 210 usb_desc = usb_otg_descriptor_alloc(cdev->gadget); 211 if (!usb_desc) { 212 status = -ENOMEM; 213 goto fail; 214 } 215 usb_otg_descriptor_init(cdev->gadget, usb_desc); 216 otg_desc[0] = usb_desc; 217 otg_desc[1] = NULL; 218 } 219 serial_config_driver.descriptors = otg_desc; 220 serial_config_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP; 221 } 222 223 /* register our configuration */ 224 if (use_acm) { 225 status = serial_register_ports(cdev, &serial_config_driver, 226 "acm"); 227 usb_ep_autoconfig_reset(cdev->gadget); 228 } else if (use_obex) 229 status = serial_register_ports(cdev, &serial_config_driver, 230 "obex"); 231 else { 232 status = serial_register_ports(cdev, &serial_config_driver, 233 "gser"); 234 } 235 if (status < 0) 236 goto fail1; 237 238 usb_composite_overwrite_options(cdev, &coverwrite); 239 INFO(cdev, "%s\n", GS_VERSION_NAME); 240 241 return 0; 242 fail1: 243 kfree(otg_desc[0]); 244 otg_desc[0] = NULL; 245 fail: 246 return status; 247 } 248 249 static int gs_unbind(struct usb_composite_dev *cdev) 250 { 251 int i; 252 253 for (i = 0; i < n_ports; i++) { 254 usb_put_function(f_serial[i]); 255 usb_put_function_instance(fi_serial[i]); 256 } 257 258 kfree(otg_desc[0]); 259 otg_desc[0] = NULL; 260 261 return 0; 262 } 263 264 static struct usb_composite_driver gserial_driver = { 265 .name = "g_serial", 266 .dev = &device_desc, 267 .strings = dev_strings, 268 .max_speed = USB_SPEED_SUPER, 269 .bind = gs_bind, 270 .unbind = gs_unbind, 271 }; 272 273 static int switch_gserial_enable(bool do_enable) 274 { 275 if (!serial_config_driver.label) 276 /* gserial_init() was not called, yet */ 277 return 0; 278 279 if (do_enable) 280 return usb_composite_probe(&gserial_driver); 281 282 usb_composite_unregister(&gserial_driver); 283 return 0; 284 } 285 286 static int __init gserial_init(void) 287 { 288 /* We *could* export two configs; that'd be much cleaner... 289 * but neither of these product IDs was defined that way. 290 */ 291 if (use_acm) { 292 serial_config_driver.label = "CDC ACM config"; 293 serial_config_driver.bConfigurationValue = 2; 294 device_desc.bDeviceClass = USB_CLASS_COMM; 295 device_desc.idProduct = 296 cpu_to_le16(GS_CDC_PRODUCT_ID); 297 } else if (use_obex) { 298 serial_config_driver.label = "CDC OBEX config"; 299 serial_config_driver.bConfigurationValue = 3; 300 device_desc.bDeviceClass = USB_CLASS_COMM; 301 device_desc.idProduct = 302 cpu_to_le16(GS_CDC_OBEX_PRODUCT_ID); 303 } else { 304 serial_config_driver.label = "Generic Serial config"; 305 serial_config_driver.bConfigurationValue = 1; 306 device_desc.bDeviceClass = USB_CLASS_VENDOR_SPEC; 307 device_desc.idProduct = 308 cpu_to_le16(GS_PRODUCT_ID); 309 } 310 strings_dev[STRING_DESCRIPTION_IDX].s = serial_config_driver.label; 311 312 if (!enable) 313 return 0; 314 315 return usb_composite_probe(&gserial_driver); 316 } 317 module_init(gserial_init); 318 319 static void __exit gserial_cleanup(void) 320 { 321 if (enable) 322 usb_composite_unregister(&gserial_driver); 323 } 324 module_exit(gserial_cleanup); 325