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/utsname.h>
  15 #include <linux/device.h>
  16 #include <linux/tty.h>
  17 #include <linux/tty_flip.h>
  18
  19 #include "u_serial.h"
  20 #include "gadget_chips.h"
  21
  22
  23 /* Defines */
  24
  25 #define GS_VERSION_STR                  "v2.4"
  26 #define GS_VERSION_NUM                  0x2400
  27
  28 #define GS_LONG_NAME                    "Gadget Serial"
  29 #define GS_VERSION_NAME                 GS_LONG_NAME " " GS_VERSION_STR
  30
  31 /*-------------------------------------------------------------------------*/
  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
  42 /* string IDs are assigned dynamically */
  43
  44 #define STRING_MANUFACTURER_IDX         0
  45 #define STRING_PRODUCT_IDX              1
  46 #define STRING_DESCRIPTION_IDX          2
  47
  48 static char manufacturer[50];
  49
  50 static struct usb_string strings_dev[] = {
  51         [STRING_MANUFACTURER_IDX].s = manufacturer,
  52         [STRING_PRODUCT_IDX].s = GS_VERSION_NAME,
  53         [STRING_DESCRIPTION_IDX].s = NULL /* updated; f(use_acm) */,
  54         {  } /* end of list */
  55 };
  56
  57 static struct usb_gadget_strings stringtab_dev = {
  58         .language       = 0x0409,       /* en-us */
  59         .strings        = strings_dev,
  60 };
  61
  62 static struct usb_gadget_strings *dev_strings[] = {
  63         &stringtab_dev,
  64         NULL,
  65 };
  66
  67 static struct usb_device_descriptor device_desc = {
  68         .bLength =              USB_DT_DEVICE_SIZE,
  69         .bDescriptorType =      USB_DT_DEVICE,
  70         .bcdUSB =               __constant_cpu_to_le16(0x0200),
  71         /* .bDeviceClass = f(use_acm) */
  72         .bDeviceSubClass =      0,
  73         .bDeviceProtocol =      0,
  74         /* .bMaxPacketSize0 = f(hardware) */
  75         .idVendor =             __constant_cpu_to_le16(GS_VENDOR_ID),
  76         /* .idProduct = f(use_acm) */
  77         /* .bcdDevice = f(hardware) */
  78         /* .iManufacturer = DYNAMIC */
  79         /* .iProduct = DYNAMIC */
  80         .bNumConfigurations =   1,
  81 };
  82
  83 static struct usb_otg_descriptor otg_descriptor = {
  84         .bLength =              sizeof otg_descriptor,
  85         .bDescriptorType =      USB_DT_OTG,
  86
  87         /* REVISIT SRP-only hardware is possible, although
  88          * it would not be called "OTG" ...
  89          */
  90         .bmAttributes =         USB_OTG_SRP | USB_OTG_HNP,
  91 };
  92
  93 static const struct usb_descriptor_header *otg_desc[] = {
  94         (struct usb_descriptor_header *) &otg_descriptor,
  95         NULL,
  96 };
  97
  98 /*-------------------------------------------------------------------------*/
  99
 100 /* Module */
 101 MODULE_DESCRIPTION(GS_VERSION_NAME);
 102 MODULE_AUTHOR("Al Borchers");
 103 MODULE_AUTHOR("David Brownell");
 104 MODULE_LICENSE("GPL");
 105
 106 static int use_acm = true;
 107 module_param(use_acm, bool, 0);
 108 MODULE_PARM_DESC(use_acm, "Use CDC ACM, default=yes");
 109
 110 static unsigned n_ports = 1;
 111 module_param(n_ports, uint, 0);
 112 MODULE_PARM_DESC(n_ports, "number of ports to create, default=1");
 113
 114 /*-------------------------------------------------------------------------*/
 115
 116 static int __init serial_bind_config(struct usb_configuration *c)
 117 {
 118         unsigned i;
 119         int status = 0;
 120
 121         for (i = 0; i < n_ports && status == 0; i++) {
 122                 if (use_acm)
 123                         status = acm_bind_config(c, i);
 124                 else
 125                         status = gser_bind_config(c, i);
 126         }
 127         return status;
 128 }
 129
 130 static struct usb_configuration serial_config_driver = {
 131         /* .label = f(use_acm) */
 132         .bind           = serial_bind_config,
 133         /* .bConfigurationValue = f(use_acm) */
 134         /* .iConfiguration = DYNAMIC */
 135         .bmAttributes   = USB_CONFIG_ATT_SELFPOWER,
 136         .bMaxPower      = 1,    /* 2 mA, minimal */
 137 };
 138
 139 static int __init gs_bind(struct usb_composite_dev *cdev)
 140 {
 141         int                     gcnum;
 142         struct usb_gadget       *gadget = cdev->gadget;
 143         int                     status;
 144
 145         status = gserial_setup(cdev->gadget, n_ports);
 146         if (status < 0)
 147                 return status;
 148
 149         /* Allocate string descriptor numbers ... note that string
 150          * contents can be overridden by the composite_dev glue.
 151          */
 152
 153         /* device description: manufacturer, product */
 154         snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
 155                 init_utsname()->sysname, init_utsname()->release,
 156                 gadget->name);
 157         status = usb_string_id(cdev);
 158         if (status < 0)
 159                 goto fail;
 160         strings_dev[STRING_MANUFACTURER_IDX].id = status;
 161
 162         device_desc.iManufacturer = status;
 163
 164         status = usb_string_id(cdev);
 165         if (status < 0)
 166                 goto fail;
 167         strings_dev[STRING_PRODUCT_IDX].id = status;
 168
 169         device_desc.iProduct = status;
 170
 171         /* config description */
 172         status = usb_string_id(cdev);
 173         if (status < 0)
 174                 goto fail;
 175         strings_dev[STRING_DESCRIPTION_IDX].id = status;
 176
 177         serial_config_driver.iConfiguration = status;
 178
 179         /* set up other descriptors */
 180         gcnum = usb_gadget_controller_number(gadget);
 181         if (gcnum >= 0)
 182                 device_desc.bcdDevice = cpu_to_le16(GS_VERSION_NUM | gcnum);
 183         else {
 184                 /* this is so simple (for now, no altsettings) that it
 185                  * SHOULD NOT have problems with bulk-capable hardware.
 186                  * so warn about unrcognized controllers -- don't panic.
 187                  *
 188                  * things like configuration and altsetting numbering
 189                  * can need hardware-specific attention though.
 190                  */
 191                 pr_warning("gs_bind: controller '%s' not recognized\n",
 192                         gadget->name);
 193                 device_desc.bcdDevice =
 194                         __constant_cpu_to_le16(GS_VERSION_NUM | 0x0099);
 195         }
 196
 197         if (gadget_is_otg(cdev->gadget)) {
 198                 serial_config_driver.descriptors = otg_desc;
 199                 serial_config_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 200         }
 201
 202         /* register our configuration */
 203         status = usb_add_config(cdev, &serial_config_driver);
 204         if (status < 0)
 205                 goto fail;
 206
 207         INFO(cdev, "%s\n", GS_VERSION_NAME);
 208
 209         return 0;
 210
 211 fail:
 212         gserial_cleanup();
 213         return status;
 214 }
 215
 216 static struct usb_composite_driver gserial_driver = {
 217         .name           = "g_serial",
 218         .dev            = &device_desc,
 219         .strings        = dev_strings,
 220         .bind           = gs_bind,
 221 };
 222
 223 static int __init init(void)
 224 {
 225         /* We *could* export two configs; that'd be much cleaner...
 226          * but neither of these product IDs was defined that way.
 227          */
 228         if (use_acm) {
 229                 serial_config_driver.label = "CDC ACM config";
 230                 serial_config_driver.bConfigurationValue = 2;
 231                 device_desc.bDeviceClass = USB_CLASS_COMM;
 232                 device_desc.idProduct =
 233                                 __constant_cpu_to_le16(GS_CDC_PRODUCT_ID);
 234         } else {
 235                 serial_config_driver.label = "Generic Serial config";
 236                 serial_config_driver.bConfigurationValue = 1;
 237                 device_desc.bDeviceClass = USB_CLASS_VENDOR_SPEC;
 238                 device_desc.idProduct =
 239                                 __constant_cpu_to_le16(GS_PRODUCT_ID);
 240         }
 241         strings_dev[STRING_DESCRIPTION_IDX].s = serial_config_driver.label;
 242
 243         return usb_composite_register(&gserial_driver);
 244 }
 245 module_init(init);
 246
 247 static void __exit cleanup(void)
 248 {
 249         usb_composite_unregister(&gserial_driver);
 250         gserial_cleanup();
 251 }
 252 module_exit(cleanup);