drivers/usb/gadget/legacy/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/module.h>
  16 #include <linux/tty.h>
  17 #include <linux/tty_flip.h>
  18
  19 #include "u_serial.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 USB_GADGET_COMPOSITE_OPTIONS();
  32
  33 /* Thanks to NetChip Technologies for donating this product ID.
  34 *
  35 * DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
  36 * Instead:  allocate your own, using normal USB-IF procedures.
  37 */
  38 #define GS_VENDOR_ID                    0x0525  /* NetChip */
  39 #define GS_PRODUCT_ID                   0xa4a6  /* Linux-USB Serial Gadget */
  40 #define GS_CDC_PRODUCT_ID               0xa4a7  /* ... as CDC-ACM */
  41 #define GS_CDC_OBEX_PRODUCT_ID          0xa4a9  /* ... as CDC-OBEX */
  42
  43 /* string IDs are assigned dynamically */
  44
  45 #define STRING_DESCRIPTION_IDX          USB_GADGET_FIRST_AVAIL_IDX
  46
  47 static struct usb_string strings_dev[] = {
  48         [USB_GADGET_MANUFACTURER_IDX].s = "",
  49         [USB_GADGET_PRODUCT_IDX].s = GS_VERSION_NAME,
  50         [USB_GADGET_SERIAL_IDX].s = "",
  51         [STRING_DESCRIPTION_IDX].s = NULL /* updated; f(use_acm) */,
  52         {  } /* end of list */
  53 };
  54
  55 static struct usb_gadget_strings stringtab_dev = {
  56         .language       = 0x0409,       /* en-us */
  57         .strings        = strings_dev,
  58 };
  59
  60 static struct usb_gadget_strings *dev_strings[] = {
  61         &stringtab_dev,
  62         NULL,
  63 };
  64
  65 static struct usb_device_descriptor device_desc = {
  66         .bLength =              USB_DT_DEVICE_SIZE,
  67         .bDescriptorType =      USB_DT_DEVICE,
  68         .bcdUSB =               cpu_to_le16(0x0200),
  69         /* .bDeviceClass = f(use_acm) */
  70         .bDeviceSubClass =      0,
  71         .bDeviceProtocol =      0,
  72         /* .bMaxPacketSize0 = f(hardware) */
  73         .idVendor =             cpu_to_le16(GS_VENDOR_ID),
  74         /* .idProduct = f(use_acm) */
  75         .bcdDevice = cpu_to_le16(GS_VERSION_NUM),
  76         /* .iManufacturer = DYNAMIC */
  77         /* .iProduct = DYNAMIC */
  78         .bNumConfigurations =   1,
  79 };
  80
  81 static const struct usb_descriptor_header *otg_desc[2];
  82
  83 /*-------------------------------------------------------------------------*/
  84
  85 /* Module */
  86 MODULE_DESCRIPTION(GS_VERSION_NAME);
  87 MODULE_AUTHOR("Al Borchers");
  88 MODULE_AUTHOR("David Brownell");
  89 MODULE_LICENSE("GPL");
  90
  91 static bool use_acm = true;
  92 module_param(use_acm, bool, 0);
  93 MODULE_PARM_DESC(use_acm, "Use CDC ACM, default=yes");
  94
  95 static bool use_obex = false;
  96 module_param(use_obex, bool, 0);
  97 MODULE_PARM_DESC(use_obex, "Use CDC OBEX, default=no");
  98
  99 static unsigned n_ports = 1;
 100 module_param(n_ports, uint, 0);
 101 MODULE_PARM_DESC(n_ports, "number of ports to create, default=1");
 102
 103 /*-------------------------------------------------------------------------*/
 104
 105 static struct usb_configuration serial_config_driver = {
 106         /* .label = f(use_acm) */
 107         /* .bConfigurationValue = f(use_acm) */
 108         /* .iConfiguration = DYNAMIC */
 109         .bmAttributes   = USB_CONFIG_ATT_SELFPOWER,
 110 };
 111
 112 static struct usb_function_instance *fi_serial[MAX_U_SERIAL_PORTS];
 113 static struct usb_function *f_serial[MAX_U_SERIAL_PORTS];
 114
 115 static int serial_register_ports(struct usb_composite_dev *cdev,
 116                 struct usb_configuration *c, const char *f_name)
 117 {
 118         int i;
 119         int ret;
 120
 121         ret = usb_add_config_only(cdev, c);
 122         if (ret)
 123                 goto out;
 124
 125         for (i = 0; i < n_ports; i++) {
 126
 127                 fi_serial[i] = usb_get_function_instance(f_name);
 128                 if (IS_ERR(fi_serial[i])) {
 129                         ret = PTR_ERR(fi_serial[i]);
 130                         goto fail;
 131                 }
 132
 133                 f_serial[i] = usb_get_function(fi_serial[i]);
 134                 if (IS_ERR(f_serial[i])) {
 135                         ret = PTR_ERR(f_serial[i]);
 136                         goto err_get_func;
 137                 }
 138
 139                 ret = usb_add_function(c, f_serial[i]);
 140                 if (ret)
 141                         goto err_add_func;
 142         }
 143
 144         return 0;
 145
 146 err_add_func:
 147         usb_put_function(f_serial[i]);
 148 err_get_func:
 149         usb_put_function_instance(fi_serial[i]);
 150
 151 fail:
 152         i--;
 153         while (i >= 0) {
 154                 usb_remove_function(c, f_serial[i]);
 155                 usb_put_function(f_serial[i]);
 156                 usb_put_function_instance(fi_serial[i]);
 157                 i--;
 158         }
 159 out:
 160         return ret;
 161 }
 162
 163 static int gs_bind(struct usb_composite_dev *cdev)
 164 {
 165         int                     status;
 166
 167         /* Allocate string descriptor numbers ... note that string
 168          * contents can be overridden by the composite_dev glue.
 169          */
 170
 171         status = usb_string_ids_tab(cdev, strings_dev);
 172         if (status < 0)
 173                 goto fail;
 174         device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
 175         device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
 176         status = strings_dev[STRING_DESCRIPTION_IDX].id;
 177         serial_config_driver.iConfiguration = status;
 178
 179         if (gadget_is_otg(cdev->gadget)) {
 180                 if (!otg_desc[0]) {
 181                         struct usb_descriptor_header *usb_desc;
 182
 183                         usb_desc = usb_otg_descriptor_alloc(cdev->gadget);
 184                         if (!usb_desc) {
 185                                 status = -ENOMEM;
 186                                 goto fail;
 187                         }
 188                         usb_otg_descriptor_init(cdev->gadget, usb_desc);
 189                         otg_desc[0] = usb_desc;
 190                         otg_desc[1] = NULL;
 191                 }
 192                 serial_config_driver.descriptors = otg_desc;
 193                 serial_config_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 194         }
 195
 196         /* register our configuration */
 197         if (use_acm) {
 198                 status  = serial_register_ports(cdev, &serial_config_driver,
 199                                 "acm");
 200                 usb_ep_autoconfig_reset(cdev->gadget);
 201         } else if (use_obex)
 202                 status = serial_register_ports(cdev, &serial_config_driver,
 203                                 "obex");
 204         else {
 205                 status = serial_register_ports(cdev, &serial_config_driver,
 206                                 "gser");
 207         }
 208         if (status < 0)
 209                 goto fail1;
 210
 211         usb_composite_overwrite_options(cdev, &coverwrite);
 212         INFO(cdev, "%s\n", GS_VERSION_NAME);
 213
 214         return 0;
 215 fail1:
 216         kfree(otg_desc[0]);
 217         otg_desc[0] = NULL;
 218 fail:
 219         return status;
 220 }
 221
 222 static int gs_unbind(struct usb_composite_dev *cdev)
 223 {
 224         int i;
 225
 226         for (i = 0; i < n_ports; i++) {
 227                 usb_put_function(f_serial[i]);
 228                 usb_put_function_instance(fi_serial[i]);
 229         }
 230
 231         kfree(otg_desc[0]);
 232         otg_desc[0] = NULL;
 233
 234         return 0;
 235 }
 236
 237 static struct usb_composite_driver gserial_driver = {
 238         .name           = "g_serial",
 239         .dev            = &device_desc,
 240         .strings        = dev_strings,
 241         .max_speed      = USB_SPEED_SUPER,
 242         .bind           = gs_bind,
 243         .unbind         = gs_unbind,
 244 };
 245
 246 static int __init init(void)
 247 {
 248         /* We *could* export two configs; that'd be much cleaner...
 249          * but neither of these product IDs was defined that way.
 250          */
 251         if (use_acm) {
 252                 serial_config_driver.label = "CDC ACM config";
 253                 serial_config_driver.bConfigurationValue = 2;
 254                 device_desc.bDeviceClass = USB_CLASS_COMM;
 255                 device_desc.idProduct =
 256                                 cpu_to_le16(GS_CDC_PRODUCT_ID);
 257         } else if (use_obex) {
 258                 serial_config_driver.label = "CDC OBEX config";
 259                 serial_config_driver.bConfigurationValue = 3;
 260                 device_desc.bDeviceClass = USB_CLASS_COMM;
 261                 device_desc.idProduct =
 262                         cpu_to_le16(GS_CDC_OBEX_PRODUCT_ID);
 263         } else {
 264                 serial_config_driver.label = "Generic Serial config";
 265                 serial_config_driver.bConfigurationValue = 1;
 266                 device_desc.bDeviceClass = USB_CLASS_VENDOR_SPEC;
 267                 device_desc.idProduct =
 268                                 cpu_to_le16(GS_PRODUCT_ID);
 269         }
 270         strings_dev[STRING_DESCRIPTION_IDX].s = serial_config_driver.label;
 271
 272         return usb_composite_probe(&gserial_driver);
 273 }
 274 module_init(init);
 275
 276 static void __exit cleanup(void)
 277 {
 278         usb_composite_unregister(&gserial_driver);
 279 }
 280 module_exit(cleanup);