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/kstrtox.h> 13 #include <linux/module.h> 14 #include <linux/tty.h> 15 #include <linux/tty_flip.h> 16 17 #include "u_serial.h" 18 19 20 /* Defines */ 21 22 #define GS_VERSION_STR "v2.4" 23 #define GS_VERSION_NUM 0x2400 24 25 #define GS_LONG_NAME "Gadget Serial" 26 #define GS_VERSION_NAME GS_LONG_NAME " " GS_VERSION_STR 27 28 /*-------------------------------------------------------------------------*/ 29 USB_GADGET_COMPOSITE_OPTIONS(); 30 31 /* Thanks to NetChip Technologies for donating this product ID. 32 * 33 * DO NOT REUSE THESE IDs with a protocol-incompatible driver!! Ever!! 34 * Instead: allocate your own, using normal USB-IF procedures. 35 */ 36 #define GS_VENDOR_ID 0x0525 /* NetChip */ 37 #define GS_PRODUCT_ID 0xa4a6 /* Linux-USB Serial Gadget */ 38 #define GS_CDC_PRODUCT_ID 0xa4a7 /* ... as CDC-ACM */ 39 #define GS_CDC_OBEX_PRODUCT_ID 0xa4a9 /* ... as CDC-OBEX */ 40 41 /* string IDs are assigned dynamically */ 42 43 #define STRING_DESCRIPTION_IDX USB_GADGET_FIRST_AVAIL_IDX 44 45 static struct usb_string strings_dev[] = { 46 [USB_GADGET_MANUFACTURER_IDX].s = "", 47 [USB_GADGET_PRODUCT_IDX].s = GS_VERSION_NAME, 48 [USB_GADGET_SERIAL_IDX].s = "", 49 [STRING_DESCRIPTION_IDX].s = NULL /* updated; f(use_acm) */, 50 { } /* end of list */ 51 }; 52 53 static struct usb_gadget_strings stringtab_dev = { 54 .language = 0x0409, /* en-us */ 55 .strings = strings_dev, 56 }; 57 58 static struct usb_gadget_strings *dev_strings[] = { 59 &stringtab_dev, 60 NULL, 61 }; 62 63 static struct usb_device_descriptor device_desc = { 64 .bLength = USB_DT_DEVICE_SIZE, 65 .bDescriptorType = USB_DT_DEVICE, 66 /* .bcdUSB = DYNAMIC */ 67 /* .bDeviceClass = f(use_acm) */ 68 .bDeviceSubClass = 0, 69 .bDeviceProtocol = 0, 70 /* .bMaxPacketSize0 = f(hardware) */ 71 .idVendor = cpu_to_le16(GS_VENDOR_ID), 72 /* .idProduct = f(use_acm) */ 73 .bcdDevice = cpu_to_le16(GS_VERSION_NUM), 74 /* .iManufacturer = DYNAMIC */ 75 /* .iProduct = DYNAMIC */ 76 .bNumConfigurations = 1, 77 }; 78 79 static const struct usb_descriptor_header *otg_desc[2]; 80 81 /*-------------------------------------------------------------------------*/ 82 83 /* Module */ 84 MODULE_DESCRIPTION(GS_VERSION_NAME); 85 MODULE_AUTHOR("Al Borchers"); 86 MODULE_AUTHOR("David Brownell"); 87 MODULE_LICENSE("GPL"); 88 89 static bool use_acm = true; 90 module_param(use_acm, bool, 0); 91 MODULE_PARM_DESC(use_acm, "Use CDC ACM, default=yes"); 92 93 static bool use_obex = false; 94 module_param(use_obex, bool, 0); 95 MODULE_PARM_DESC(use_obex, "Use CDC OBEX, default=no"); 96 97 static unsigned n_ports = 1; 98 module_param(n_ports, uint, 0); 99 MODULE_PARM_DESC(n_ports, "number of ports to create, default=1"); 100 101 static bool enable = true; 102 103 static int switch_gserial_enable(bool do_enable); 104 105 static int enable_set(const char *s, const struct kernel_param *kp) 106 { 107 bool do_enable; 108 int ret; 109 110 if (!s) /* called for no-arg enable == default */ 111 return 0; 112 113 ret = kstrtobool(s, &do_enable); 114 if (ret || enable == do_enable) 115 return ret; 116 117 ret = switch_gserial_enable(do_enable); 118 if (!ret) 119 enable = do_enable; 120 121 return ret; 122 } 123 124 static const struct kernel_param_ops enable_ops = { 125 .set = enable_set, 126 .get = param_get_bool, 127 }; 128 129 module_param_cb(enable, &enable_ops, &enable, 0644); 130 131 /*-------------------------------------------------------------------------*/ 132 133 static struct usb_configuration serial_config_driver = { 134 /* .label = f(use_acm) */ 135 /* .bConfigurationValue = f(use_acm) */ 136 /* .iConfiguration = DYNAMIC */ 137 .bmAttributes = USB_CONFIG_ATT_SELFPOWER, 138 }; 139 140 static struct usb_function_instance *fi_serial[MAX_U_SERIAL_PORTS]; 141 static struct usb_function *f_serial[MAX_U_SERIAL_PORTS]; 142 143 static int serial_register_ports(struct usb_composite_dev *cdev, 144 struct usb_configuration *c, const char *f_name) 145 { 146 int i; 147 int ret; 148 149 ret = usb_add_config_only(cdev, c); 150 if (ret) 151 goto out; 152 153 for (i = 0; i < n_ports; i++) { 154 155 fi_serial[i] = usb_get_function_instance(f_name); 156 if (IS_ERR(fi_serial[i])) { 157 ret = PTR_ERR(fi_serial[i]); 158 goto fail; 159 } 160 161 f_serial[i] = usb_get_function(fi_serial[i]); 162 if (IS_ERR(f_serial[i])) { 163 ret = PTR_ERR(f_serial[i]); 164 goto err_get_func; 165 } 166 167 ret = usb_add_function(c, f_serial[i]); 168 if (ret) 169 goto err_add_func; 170 } 171 172 return 0; 173 174 err_add_func: 175 usb_put_function(f_serial[i]); 176 err_get_func: 177 usb_put_function_instance(fi_serial[i]); 178 179 fail: 180 i--; 181 while (i >= 0) { 182 usb_remove_function(c, f_serial[i]); 183 usb_put_function(f_serial[i]); 184 usb_put_function_instance(fi_serial[i]); 185 i--; 186 } 187 out: 188 return ret; 189 } 190 191 static int gs_bind(struct usb_composite_dev *cdev) 192 { 193 int status; 194 195 /* Allocate string descriptor numbers ... note that string 196 * contents can be overridden by the composite_dev glue. 197 */ 198 199 status = usb_string_ids_tab(cdev, strings_dev); 200 if (status < 0) 201 goto fail; 202 device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id; 203 device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id; 204 status = strings_dev[STRING_DESCRIPTION_IDX].id; 205 serial_config_driver.iConfiguration = status; 206 207 if (gadget_is_otg(cdev->gadget)) { 208 if (!otg_desc[0]) { 209 struct usb_descriptor_header *usb_desc; 210 211 usb_desc = usb_otg_descriptor_alloc(cdev->gadget); 212 if (!usb_desc) { 213 status = -ENOMEM; 214 goto fail; 215 } 216 usb_otg_descriptor_init(cdev->gadget, usb_desc); 217 otg_desc[0] = usb_desc; 218 otg_desc[1] = NULL; 219 } 220 serial_config_driver.descriptors = otg_desc; 221 serial_config_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP; 222 } 223 224 /* register our configuration */ 225 if (use_acm) { 226 status = serial_register_ports(cdev, &serial_config_driver, 227 "acm"); 228 usb_ep_autoconfig_reset(cdev->gadget); 229 } else if (use_obex) 230 status = serial_register_ports(cdev, &serial_config_driver, 231 "obex"); 232 else { 233 status = serial_register_ports(cdev, &serial_config_driver, 234 "gser"); 235 } 236 if (status < 0) 237 goto fail1; 238 239 usb_composite_overwrite_options(cdev, &coverwrite); 240 INFO(cdev, "%s\n", GS_VERSION_NAME); 241 242 return 0; 243 fail1: 244 kfree(otg_desc[0]); 245 otg_desc[0] = NULL; 246 fail: 247 return status; 248 } 249 250 static int gs_unbind(struct usb_composite_dev *cdev) 251 { 252 int i; 253 254 for (i = 0; i < n_ports; i++) { 255 usb_put_function(f_serial[i]); 256 usb_put_function_instance(fi_serial[i]); 257 } 258 259 kfree(otg_desc[0]); 260 otg_desc[0] = NULL; 261 262 return 0; 263 } 264 265 static struct usb_composite_driver gserial_driver = { 266 .name = "g_serial", 267 .dev = &device_desc, 268 .strings = dev_strings, 269 .max_speed = USB_SPEED_SUPER, 270 .bind = gs_bind, 271 .unbind = gs_unbind, 272 }; 273 274 static int switch_gserial_enable(bool do_enable) 275 { 276 if (!serial_config_driver.label) 277 /* gserial_init() was not called, yet */ 278 return 0; 279 280 if (do_enable) 281 return usb_composite_probe(&gserial_driver); 282 283 usb_composite_unregister(&gserial_driver); 284 return 0; 285 } 286 287 static int __init gserial_init(void) 288 { 289 /* We *could* export two configs; that'd be much cleaner... 290 * but neither of these product IDs was defined that way. 291 */ 292 if (use_acm) { 293 serial_config_driver.label = "CDC ACM config"; 294 serial_config_driver.bConfigurationValue = 2; 295 device_desc.bDeviceClass = USB_CLASS_COMM; 296 device_desc.idProduct = 297 cpu_to_le16(GS_CDC_PRODUCT_ID); 298 } else if (use_obex) { 299 serial_config_driver.label = "CDC OBEX config"; 300 serial_config_driver.bConfigurationValue = 3; 301 device_desc.bDeviceClass = USB_CLASS_COMM; 302 device_desc.idProduct = 303 cpu_to_le16(GS_CDC_OBEX_PRODUCT_ID); 304 } else { 305 serial_config_driver.label = "Generic Serial config"; 306 serial_config_driver.bConfigurationValue = 1; 307 device_desc.bDeviceClass = USB_CLASS_VENDOR_SPEC; 308 device_desc.idProduct = 309 cpu_to_le16(GS_PRODUCT_ID); 310 } 311 strings_dev[STRING_DESCRIPTION_IDX].s = serial_config_driver.label; 312 313 if (!enable) 314 return 0; 315 316 return usb_composite_probe(&gserial_driver); 317 } 318 module_init(gserial_init); 319 320 static void __exit gserial_cleanup(void) 321 { 322 if (enable) 323 usb_composite_unregister(&gserial_driver); 324 } 325 module_exit(gserial_cleanup); 326