drivers/usb/gadget/legacy/serial.c

   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 /*-------------------------------------------------------------------------*/
 101
 102 static struct usb_configuration serial_config_driver = {
 103         /* .label = f(use_acm) */
 104         /* .bConfigurationValue = f(use_acm) */
 105         /* .iConfiguration = DYNAMIC */
 106         .bmAttributes   = USB_CONFIG_ATT_SELFPOWER,
 107 };
 108
 109 static struct usb_function_instance *fi_serial[MAX_U_SERIAL_PORTS];
 110 static struct usb_function *f_serial[MAX_U_SERIAL_PORTS];
 111
 112 static int serial_register_ports(struct usb_composite_dev *cdev,
 113                 struct usb_configuration *c, const char *f_name)
 114 {
 115         int i;
 116         int ret;
 117
 118         ret = usb_add_config_only(cdev, c);
 119         if (ret)
 120                 goto out;
 121
 122         for (i = 0; i < n_ports; i++) {
 123
 124                 fi_serial[i] = usb_get_function_instance(f_name);
 125                 if (IS_ERR(fi_serial[i])) {
 126                         ret = PTR_ERR(fi_serial[i]);
 127                         goto fail;
 128                 }
 129
 130                 f_serial[i] = usb_get_function(fi_serial[i]);
 131                 if (IS_ERR(f_serial[i])) {
 132                         ret = PTR_ERR(f_serial[i]);
 133                         goto err_get_func;
 134                 }
 135
 136                 ret = usb_add_function(c, f_serial[i]);
 137                 if (ret)
 138                         goto err_add_func;
 139         }
 140
 141         return 0;
 142
 143 err_add_func:
 144         usb_put_function(f_serial[i]);
 145 err_get_func:
 146         usb_put_function_instance(fi_serial[i]);
 147
 148 fail:
 149         i--;
 150         while (i >= 0) {
 151                 usb_remove_function(c, f_serial[i]);
 152                 usb_put_function(f_serial[i]);
 153                 usb_put_function_instance(fi_serial[i]);
 154                 i--;
 155         }
 156 out:
 157         return ret;
 158 }
 159
 160 static int gs_bind(struct usb_composite_dev *cdev)
 161 {
 162         int                     status;
 163
 164         /* Allocate string descriptor numbers ... note that string
 165          * contents can be overridden by the composite_dev glue.
 166          */
 167
 168         status = usb_string_ids_tab(cdev, strings_dev);
 169         if (status < 0)
 170                 goto fail;
 171         device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
 172         device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
 173         status = strings_dev[STRING_DESCRIPTION_IDX].id;
 174         serial_config_driver.iConfiguration = status;
 175
 176         if (gadget_is_otg(cdev->gadget)) {
 177                 if (!otg_desc[0]) {
 178                         struct usb_descriptor_header *usb_desc;
 179
 180                         usb_desc = usb_otg_descriptor_alloc(cdev->gadget);
 181                         if (!usb_desc) {
 182                                 status = -ENOMEM;
 183                                 goto fail;
 184                         }
 185                         usb_otg_descriptor_init(cdev->gadget, usb_desc);
 186                         otg_desc[0] = usb_desc;
 187                         otg_desc[1] = NULL;
 188                 }
 189                 serial_config_driver.descriptors = otg_desc;
 190                 serial_config_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 191         }
 192
 193         /* register our configuration */
 194         if (use_acm) {
 195                 status  = serial_register_ports(cdev, &serial_config_driver,
 196                                 "acm");
 197                 usb_ep_autoconfig_reset(cdev->gadget);
 198         } else if (use_obex)
 199                 status = serial_register_ports(cdev, &serial_config_driver,
 200                                 "obex");
 201         else {
 202                 status = serial_register_ports(cdev, &serial_config_driver,
 203                                 "gser");
 204         }
 205         if (status < 0)
 206                 goto fail1;
 207
 208         usb_composite_overwrite_options(cdev, &coverwrite);
 209         INFO(cdev, "%s\n", GS_VERSION_NAME);
 210
 211         return 0;
 212 fail1:
 213         kfree(otg_desc[0]);
 214         otg_desc[0] = NULL;
 215 fail:
 216         return status;
 217 }
 218
 219 static int gs_unbind(struct usb_composite_dev *cdev)
 220 {
 221         int i;
 222
 223         for (i = 0; i < n_ports; i++) {
 224                 usb_put_function(f_serial[i]);
 225                 usb_put_function_instance(fi_serial[i]);
 226         }
 227
 228         kfree(otg_desc[0]);
 229         otg_desc[0] = NULL;
 230
 231         return 0;
 232 }
 233
 234 static struct usb_composite_driver gserial_driver = {
 235         .name           = "g_serial",
 236         .dev            = &device_desc,
 237         .strings        = dev_strings,
 238         .max_speed      = USB_SPEED_SUPER,
 239         .bind           = gs_bind,
 240         .unbind         = gs_unbind,
 241 };
 242
 243 static int __init init(void)
 244 {
 245         /* We *could* export two configs; that'd be much cleaner...
 246          * but neither of these product IDs was defined that way.
 247          */
 248         if (use_acm) {
 249                 serial_config_driver.label = "CDC ACM config";
 250                 serial_config_driver.bConfigurationValue = 2;
 251                 device_desc.bDeviceClass = USB_CLASS_COMM;
 252                 device_desc.idProduct =
 253                                 cpu_to_le16(GS_CDC_PRODUCT_ID);
 254         } else if (use_obex) {
 255                 serial_config_driver.label = "CDC OBEX config";
 256                 serial_config_driver.bConfigurationValue = 3;
 257                 device_desc.bDeviceClass = USB_CLASS_COMM;
 258                 device_desc.idProduct =
 259                         cpu_to_le16(GS_CDC_OBEX_PRODUCT_ID);
 260         } else {
 261                 serial_config_driver.label = "Generic Serial config";
 262                 serial_config_driver.bConfigurationValue = 1;
 263                 device_desc.bDeviceClass = USB_CLASS_VENDOR_SPEC;
 264                 device_desc.idProduct =
 265                                 cpu_to_le16(GS_PRODUCT_ID);
 266         }
 267         strings_dev[STRING_DESCRIPTION_IDX].s = serial_config_driver.label;
 268
 269         return usb_composite_probe(&gserial_driver);
 270 }
 271 module_init(init);
 272
 273 static void __exit cleanup(void)
 274 {
 275         usb_composite_unregister(&gserial_driver);
 276 }
 277 module_exit(cleanup);