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 #include "f_obex.c"
  40 #include "f_serial.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 int __init serial_bind_gser_config(struct usb_configuration *c)
 142 {
 143         unsigned i;
 144         int status = 0;
 145
 146         for (i = 0; i < n_ports && status == 0; i++)
 147                 status = gser_bind_config(c, tty_lines[i]);
 148         return status;
 149 }
 150
 151 static struct usb_configuration serial_config_driver = {
 152         /* .label = f(use_acm) */
 153         /* .bConfigurationValue = f(use_acm) */
 154         /* .iConfiguration = DYNAMIC */
 155         .bmAttributes   = USB_CONFIG_ATT_SELFPOWER,
 156 };
 157
 158 static struct usb_function_instance *fi_serial[MAX_U_SERIAL_PORTS];
 159 static struct usb_function *f_serial[MAX_U_SERIAL_PORTS];
 160
 161 static int serial_register_ports(struct usb_composite_dev *cdev,
 162                 struct usb_configuration *c, const char *f_name)
 163 {
 164         int i;
 165         int ret;
 166
 167         ret = usb_add_config_only(cdev, c);
 168         if (ret)
 169                 goto out;
 170
 171         for (i = 0; i < n_ports; i++) {
 172                 struct f_serial_opts *opts;
 173
 174                 fi_serial[i] = usb_get_function_instance(f_name);
 175                 if (IS_ERR(fi_serial[i])) {
 176                         ret = PTR_ERR(fi_serial[i]);
 177                         goto fail;
 178                 }
 179                 opts = container_of(fi_serial[i], struct f_serial_opts, func_inst);
 180                 opts->port_num = tty_lines[i];
 181
 182                 f_serial[i] = usb_get_function(fi_serial[i]);
 183                 if (IS_ERR(f_serial[i])) {
 184                         ret = PTR_ERR(f_serial[i]);
 185                         goto err_get_func;
 186                 }
 187
 188                 ret = usb_add_function(c, f_serial[i]);
 189                 if (ret)
 190                         goto err_add_func;
 191         }
 192
 193         return 0;
 194
 195 err_add_func:
 196         usb_put_function(f_serial[i]);
 197 err_get_func:
 198         usb_put_function_instance(fi_serial[i]);
 199
 200 fail:
 201         i--;
 202         while (i >= 0) {
 203                 usb_remove_function(c, f_serial[i]);
 204                 usb_put_function(f_serial[i]);
 205                 usb_put_function_instance(fi_serial[i]);
 206                 i--;
 207         }
 208 out:
 209         return ret;
 210 }
 211
 212 static int __init gs_bind(struct usb_composite_dev *cdev)
 213 {
 214         int                     status;
 215         int                     cur_line;
 216
 217         for (cur_line = 0; cur_line < n_ports; cur_line++) {
 218                 status = gserial_alloc_line(&tty_lines[cur_line]);
 219                 if (status)
 220                         goto fail;
 221         }
 222
 223         /* Allocate string descriptor numbers ... note that string
 224          * contents can be overridden by the composite_dev glue.
 225          */
 226
 227         status = usb_string_ids_tab(cdev, strings_dev);
 228         if (status < 0)
 229                 goto fail;
 230         device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
 231         device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
 232         status = strings_dev[STRING_DESCRIPTION_IDX].id;
 233         serial_config_driver.iConfiguration = status;
 234
 235         if (gadget_is_otg(cdev->gadget)) {
 236                 serial_config_driver.descriptors = otg_desc;
 237                 serial_config_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 238         }
 239
 240         /* register our configuration */
 241         if (use_acm) {
 242                 status  = serial_register_ports(cdev, &serial_config_driver,
 243                                 "acm");
 244                 usb_ep_autoconfig_reset(cdev->gadget);
 245         } else if (use_obex)
 246                 status = usb_add_config(cdev, &serial_config_driver,
 247                                 serial_bind_obex_config);
 248         else
 249                 status = usb_add_config(cdev, &serial_config_driver,
 250                                 serial_bind_gser_config);
 251         if (status < 0)
 252                 goto fail;
 253
 254         usb_composite_overwrite_options(cdev, &coverwrite);
 255         INFO(cdev, "%s\n", GS_VERSION_NAME);
 256
 257         return 0;
 258
 259 fail:
 260         cur_line--;
 261         while (cur_line >= 0)
 262                 gserial_free_line(tty_lines[cur_line--]);
 263         return status;
 264 }
 265
 266 static int gs_unbind(struct usb_composite_dev *cdev)
 267 {
 268         int i;
 269
 270         for (i = 0; i < n_ports; i++) {
 271                 usb_put_function(f_serial[i]);
 272                 usb_put_function_instance(fi_serial[i]);
 273                 gserial_free_line(tty_lines[i]);
 274         }
 275         return 0;
 276 }
 277
 278 static __refdata struct usb_composite_driver gserial_driver = {
 279         .name           = "g_serial",
 280         .dev            = &device_desc,
 281         .strings        = dev_strings,
 282         .max_speed      = USB_SPEED_SUPER,
 283         .bind           = gs_bind,
 284         .unbind         = gs_unbind,
 285 };
 286
 287 static int __init 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         return usb_composite_probe(&gserial_driver);
 314 }
 315 module_init(init);
 316
 317 static void __exit cleanup(void)
 318 {
 319         usb_composite_unregister(&gserial_driver);
 320 }
 321 module_exit(cleanup);