drivers/usb/gadget/serial.c

   1 /*
   2  * serial.c -- USB gadget serial 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/kernel.h>
  14 #include <linux/device.h>
  15 #include <linux/tty.h>
  16 #include <linux/tty_flip.h>
  17
  18 #include "u_serial.h"
  19 #include "gadget_chips.h"
  20
  21
  22 /* Defines */
  23
  24 #define GS_VERSION_STR                  "v2.4"
  25 #define GS_VERSION_NUM                  0x2400
  26
  27 #define GS_LONG_NAME                    "Gadget Serial"
  28 #define GS_VERSION_NAME                 GS_LONG_NAME " " GS_VERSION_STR
  29
  30 /*-------------------------------------------------------------------------*/
  31
  32 /*
  33  * Kbuild is not very cooperative with respect to linking separately
  34  * compiled library objects into one module.  So for now we won't use
  35  * separate compilation ... ensuring init/exit sections work to shrink
  36  * the runtime footprint, and giving us at least some parts of what
  37  * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
  38  */
  39 #define USBF_OBEX_INCLUDED
  40 #include "f_obex.c"
  41
  42 /*-------------------------------------------------------------------------*/
  43 USB_GADGET_COMPOSITE_OPTIONS();
  44
  45 /* Thanks to NetChip Technologies for donating this product ID.
  46 *
  47 * DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
  48 * Instead:  allocate your own, using normal USB-IF procedures.
  49 */
  50 #define GS_VENDOR_ID                    0x0525  /* NetChip */
  51 #define GS_PRODUCT_ID                   0xa4a6  /* Linux-USB Serial Gadget */
  52 #define GS_CDC_PRODUCT_ID               0xa4a7  /* ... as CDC-ACM */
  53 #define GS_CDC_OBEX_PRODUCT_ID          0xa4a9  /* ... as CDC-OBEX */
  54
  55 /* string IDs are assigned dynamically */
  56
  57 #define STRING_DESCRIPTION_IDX          USB_GADGET_FIRST_AVAIL_IDX
  58
  59 static struct usb_string strings_dev[] = {
  60         [USB_GADGET_MANUFACTURER_IDX].s = "",
  61         [USB_GADGET_PRODUCT_IDX].s = GS_VERSION_NAME,
  62         [USB_GADGET_SERIAL_IDX].s = "",
  63         [STRING_DESCRIPTION_IDX].s = NULL /* updated; f(use_acm) */,
  64         {  } /* end of list */
  65 };
  66
  67 static struct usb_gadget_strings stringtab_dev = {
  68         .language       = 0x0409,       /* en-us */
  69         .strings        = strings_dev,
  70 };
  71
  72 static struct usb_gadget_strings *dev_strings[] = {
  73         &stringtab_dev,
  74         NULL,
  75 };
  76
  77 static struct usb_device_descriptor device_desc = {
  78         .bLength =              USB_DT_DEVICE_SIZE,
  79         .bDescriptorType =      USB_DT_DEVICE,
  80         .bcdUSB =               cpu_to_le16(0x0200),
  81         /* .bDeviceClass = f(use_acm) */
  82         .bDeviceSubClass =      0,
  83         .bDeviceProtocol =      0,
  84         /* .bMaxPacketSize0 = f(hardware) */
  85         .idVendor =             cpu_to_le16(GS_VENDOR_ID),
  86         /* .idProduct = f(use_acm) */
  87         .bcdDevice = cpu_to_le16(GS_VERSION_NUM),
  88         /* .iManufacturer = DYNAMIC */
  89         /* .iProduct = DYNAMIC */
  90         .bNumConfigurations =   1,
  91 };
  92
  93 static struct usb_otg_descriptor otg_descriptor = {
  94         .bLength =              sizeof otg_descriptor,
  95         .bDescriptorType =      USB_DT_OTG,
  96
  97         /* REVISIT SRP-only hardware is possible, although
  98          * it would not be called "OTG" ...
  99          */
 100         .bmAttributes =         USB_OTG_SRP | USB_OTG_HNP,
 101 };
 102
 103 static const struct usb_descriptor_header *otg_desc[] = {
 104         (struct usb_descriptor_header *) &otg_descriptor,
 105         NULL,
 106 };
 107
 108 /*-------------------------------------------------------------------------*/
 109
 110 /* Module */
 111 MODULE_DESCRIPTION(GS_VERSION_NAME);
 112 MODULE_AUTHOR("Al Borchers");
 113 MODULE_AUTHOR("David Brownell");
 114 MODULE_LICENSE("GPL");
 115
 116 static bool use_acm = true;
 117 module_param(use_acm, bool, 0);
 118 MODULE_PARM_DESC(use_acm, "Use CDC ACM, default=yes");
 119
 120 static bool use_obex = false;
 121 module_param(use_obex, bool, 0);
 122 MODULE_PARM_DESC(use_obex, "Use CDC OBEX, default=no");
 123
 124 static unsigned n_ports = 1;
 125 module_param(n_ports, uint, 0);
 126 MODULE_PARM_DESC(n_ports, "number of ports to create, default=1");
 127
 128 /*-------------------------------------------------------------------------*/
 129 static unsigned char tty_lines[MAX_U_SERIAL_PORTS];
 130
 131 static int __init serial_bind_obex_config(struct usb_configuration *c)
 132 {
 133         unsigned i;
 134         int status = 0;
 135
 136         for (i = 0; i < n_ports && status == 0; i++)
 137                 status = obex_bind_config(c, tty_lines[i]);
 138         return status;
 139 }
 140
 141 static struct usb_configuration serial_config_driver = {
 142         /* .label = f(use_acm) */
 143         /* .bConfigurationValue = f(use_acm) */
 144         /* .iConfiguration = DYNAMIC */
 145         .bmAttributes   = USB_CONFIG_ATT_SELFPOWER,
 146 };
 147
 148 static struct usb_function_instance *fi_serial[MAX_U_SERIAL_PORTS];
 149 static struct usb_function *f_serial[MAX_U_SERIAL_PORTS];
 150
 151 static int serial_register_ports(struct usb_composite_dev *cdev,
 152                 struct usb_configuration *c, const char *f_name)
 153 {
 154         int i;
 155         int ret;
 156
 157         ret = usb_add_config_only(cdev, c);
 158         if (ret)
 159                 goto out;
 160
 161         for (i = 0; i < n_ports; i++) {
 162
 163                 fi_serial[i] = usb_get_function_instance(f_name);
 164                 if (IS_ERR(fi_serial[i])) {
 165                         ret = PTR_ERR(fi_serial[i]);
 166                         goto fail;
 167                 }
 168
 169                 f_serial[i] = usb_get_function(fi_serial[i]);
 170                 if (IS_ERR(f_serial[i])) {
 171                         ret = PTR_ERR(f_serial[i]);
 172                         goto err_get_func;
 173                 }
 174
 175                 ret = usb_add_function(c, f_serial[i]);
 176                 if (ret)
 177                         goto err_add_func;
 178         }
 179
 180         return 0;
 181
 182 err_add_func:
 183         usb_put_function(f_serial[i]);
 184 err_get_func:
 185         usb_put_function_instance(fi_serial[i]);
 186
 187 fail:
 188         i--;
 189         while (i >= 0) {
 190                 usb_remove_function(c, f_serial[i]);
 191                 usb_put_function(f_serial[i]);
 192                 usb_put_function_instance(fi_serial[i]);
 193                 i--;
 194         }
 195 out:
 196         return ret;
 197 }
 198
 199 static int __init gs_bind(struct usb_composite_dev *cdev)
 200 {
 201         int                     status;
 202         int                     cur_line = 0;
 203
 204         if (use_obex) {
 205                 for (cur_line = 0; cur_line < n_ports; cur_line++) {
 206                         status = gserial_alloc_line(&tty_lines[cur_line]);
 207                         if (status)
 208                                 goto fail;
 209                 }
 210         }
 211
 212         /* Allocate string descriptor numbers ... note that string
 213          * contents can be overridden by the composite_dev glue.
 214          */
 215
 216         status = usb_string_ids_tab(cdev, strings_dev);
 217         if (status < 0)
 218                 goto fail;
 219         device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
 220         device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
 221         status = strings_dev[STRING_DESCRIPTION_IDX].id;
 222         serial_config_driver.iConfiguration = status;
 223
 224         if (gadget_is_otg(cdev->gadget)) {
 225                 serial_config_driver.descriptors = otg_desc;
 226                 serial_config_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 227         }
 228
 229         /* register our configuration */
 230         if (use_acm) {
 231                 status  = serial_register_ports(cdev, &serial_config_driver,
 232                                 "acm");
 233                 usb_ep_autoconfig_reset(cdev->gadget);
 234         } else if (use_obex)
 235                 status = usb_add_config(cdev, &serial_config_driver,
 236                                 serial_bind_obex_config);
 237         else {
 238                 status = serial_register_ports(cdev, &serial_config_driver,
 239                                 "gser");
 240         }
 241         if (status < 0)
 242                 goto fail;
 243
 244         usb_composite_overwrite_options(cdev, &coverwrite);
 245         INFO(cdev, "%s\n", GS_VERSION_NAME);
 246
 247         return 0;
 248
 249 fail:
 250         cur_line--;
 251         while (cur_line >= 0 && use_obex)
 252                 gserial_free_line(tty_lines[cur_line--]);
 253         return status;
 254 }
 255
 256 static int gs_unbind(struct usb_composite_dev *cdev)
 257 {
 258         int i;
 259
 260         for (i = 0; i < n_ports; i++) {
 261                 usb_put_function(f_serial[i]);
 262                 usb_put_function_instance(fi_serial[i]);
 263                 if (use_obex)
 264                         gserial_free_line(tty_lines[i]);
 265         }
 266         return 0;
 267 }
 268
 269 static __refdata struct usb_composite_driver gserial_driver = {
 270         .name           = "g_serial",
 271         .dev            = &device_desc,
 272         .strings        = dev_strings,
 273         .max_speed      = USB_SPEED_SUPER,
 274         .bind           = gs_bind,
 275         .unbind         = gs_unbind,
 276 };
 277
 278 static int __init init(void)
 279 {
 280         /* We *could* export two configs; that'd be much cleaner...
 281          * but neither of these product IDs was defined that way.
 282          */
 283         if (use_acm) {
 284                 serial_config_driver.label = "CDC ACM config";
 285                 serial_config_driver.bConfigurationValue = 2;
 286                 device_desc.bDeviceClass = USB_CLASS_COMM;
 287                 device_desc.idProduct =
 288                                 cpu_to_le16(GS_CDC_PRODUCT_ID);
 289         } else if (use_obex) {
 290                 serial_config_driver.label = "CDC OBEX config";
 291                 serial_config_driver.bConfigurationValue = 3;
 292                 device_desc.bDeviceClass = USB_CLASS_COMM;
 293                 device_desc.idProduct =
 294                         cpu_to_le16(GS_CDC_OBEX_PRODUCT_ID);
 295         } else {
 296                 serial_config_driver.label = "Generic Serial config";
 297                 serial_config_driver.bConfigurationValue = 1;
 298                 device_desc.bDeviceClass = USB_CLASS_VENDOR_SPEC;
 299                 device_desc.idProduct =
 300                                 cpu_to_le16(GS_PRODUCT_ID);
 301         }
 302         strings_dev[STRING_DESCRIPTION_IDX].s = serial_config_driver.label;
 303
 304         return usb_composite_probe(&gserial_driver);
 305 }
 306 module_init(init);
 307
 308 static void __exit cleanup(void)
 309 {
 310         usb_composite_unregister(&gserial_driver);
 311 }
 312 module_exit(cleanup);