drivers/usb/gadget/audio.c

   1 /*
   2  * audio.c -- Audio gadget driver
   3  *
   4  * Copyright (C) 2008 Bryan Wu <cooloney@kernel.org>
   5  * Copyright (C) 2008 Analog Devices, Inc
   6  *
   7  * Enter bugs at http://blackfin.uclinux.org/
   8  *
   9  * Licensed under the GPL-2 or later.
  10  */
  11
  12 /* #define VERBOSE_DEBUG */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/utsname.h>
  16
  17 #include "u_audio.h"
  18
  19 #define DRIVER_DESC             "Linux USB Audio Gadget"
  20 #define DRIVER_VERSION          "Dec 18, 2008"
  21
  22 /*-------------------------------------------------------------------------*/
  23
  24 /*
  25  * Kbuild is not very cooperative with respect to linking separately
  26  * compiled library objects into one module.  So for now we won't use
  27  * separate compilation ... ensuring init/exit sections work to shrink
  28  * the runtime footprint, and giving us at least some parts of what
  29  * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
  30  */
  31 #include "composite.c"
  32 #include "usbstring.c"
  33 #include "config.c"
  34 #include "epautoconf.c"
  35
  36 #include "u_audio.c"
  37 #include "f_audio.c"
  38
  39 /*-------------------------------------------------------------------------*/
  40
  41 /* DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
  42  * Instead:  allocate your own, using normal USB-IF procedures.
  43  */
  44
  45 /* Thanks to Linux Foundation for donating this product ID. */
  46 #define AUDIO_VENDOR_NUM                0x1d6b  /* Linux Foundation */
  47 #define AUDIO_PRODUCT_NUM               0x0101  /* Linux-USB Audio Gadget */
  48
  49 /*-------------------------------------------------------------------------*/
  50
  51 static struct usb_device_descriptor device_desc = {
  52         .bLength =              sizeof device_desc,
  53         .bDescriptorType =      USB_DT_DEVICE,
  54
  55         .bcdUSB =               __constant_cpu_to_le16(0x200),
  56
  57         .bDeviceClass =         USB_CLASS_PER_INTERFACE,
  58         .bDeviceSubClass =      0,
  59         .bDeviceProtocol =      0,
  60         /* .bMaxPacketSize0 = f(hardware) */
  61
  62         /* Vendor and product id defaults change according to what configs
  63          * we support.  (As does bNumConfigurations.)  These values can
  64          * also be overridden by module parameters.
  65          */
  66         .idVendor =             __constant_cpu_to_le16(AUDIO_VENDOR_NUM),
  67         .idProduct =            __constant_cpu_to_le16(AUDIO_PRODUCT_NUM),
  68         /* .bcdDevice = f(hardware) */
  69         /* .iManufacturer = DYNAMIC */
  70         /* .iProduct = DYNAMIC */
  71         /* NO SERIAL NUMBER */
  72         .bNumConfigurations =   1,
  73 };
  74
  75 static struct usb_otg_descriptor otg_descriptor = {
  76         .bLength =              sizeof otg_descriptor,
  77         .bDescriptorType =      USB_DT_OTG,
  78
  79         /* REVISIT SRP-only hardware is possible, although
  80          * it would not be called "OTG" ...
  81          */
  82         .bmAttributes =         USB_OTG_SRP | USB_OTG_HNP,
  83 };
  84
  85 static const struct usb_descriptor_header *otg_desc[] = {
  86         (struct usb_descriptor_header *) &otg_descriptor,
  87         NULL,
  88 };
  89
  90 /*-------------------------------------------------------------------------*/
  91
  92 /**
  93  * Handle USB audio endpoint set/get command in setup class request
  94  */
  95
  96 static int audio_set_endpoint_req(struct usb_configuration *c,
  97                 const struct usb_ctrlrequest *ctrl)
  98 {
  99         struct usb_composite_dev *cdev = c->cdev;
 100         int                     value = -EOPNOTSUPP;
 101         u16                     ep = le16_to_cpu(ctrl->wIndex);
 102         u16                     len = le16_to_cpu(ctrl->wLength);
 103         u16                     w_value = le16_to_cpu(ctrl->wValue);
 104
 105         DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
 106                         ctrl->bRequest, w_value, len, ep);
 107
 108         switch (ctrl->bRequest) {
 109         case SET_CUR:
 110                 value = 0;
 111                 break;
 112
 113         case SET_MIN:
 114                 break;
 115
 116         case SET_MAX:
 117                 break;
 118
 119         case SET_RES:
 120                 break;
 121
 122         case SET_MEM:
 123                 break;
 124
 125         default:
 126                 break;
 127         }
 128
 129         return value;
 130 }
 131
 132 static int audio_get_endpoint_req(struct usb_configuration *c,
 133                 const struct usb_ctrlrequest *ctrl)
 134 {
 135         struct usb_composite_dev *cdev = c->cdev;
 136         int value = -EOPNOTSUPP;
 137         u8 ep = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 138         u16 len = le16_to_cpu(ctrl->wLength);
 139         u16 w_value = le16_to_cpu(ctrl->wValue);
 140
 141         DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
 142                         ctrl->bRequest, w_value, len, ep);
 143
 144         switch (ctrl->bRequest) {
 145         case GET_CUR:
 146         case GET_MIN:
 147         case GET_MAX:
 148         case GET_RES:
 149                 value = 3;
 150                 break;
 151         case GET_MEM:
 152                 break;
 153         default:
 154                 break;
 155         }
 156
 157         return value;
 158 }
 159
 160 static int
 161 audio_setup(struct usb_configuration *c, const struct usb_ctrlrequest *ctrl)
 162 {
 163         struct usb_composite_dev *cdev = c->cdev;
 164         struct usb_request *req = cdev->req;
 165         int value = -EOPNOTSUPP;
 166         u16 w_index = le16_to_cpu(ctrl->wIndex);
 167         u16 w_value = le16_to_cpu(ctrl->wValue);
 168         u16 w_length = le16_to_cpu(ctrl->wLength);
 169
 170         /* composite driver infrastructure handles everything except
 171          * Audio class messages; interface activation uses set_alt().
 172          */
 173         switch (ctrl->bRequestType) {
 174         case USB_AUDIO_SET_ENDPOINT:
 175                 value = audio_set_endpoint_req(c, ctrl);
 176                 break;
 177
 178         case USB_AUDIO_GET_ENDPOINT:
 179                 value = audio_get_endpoint_req(c, ctrl);
 180                 break;
 181
 182         default:
 183                 ERROR(cdev, "Invalid control req%02x.%02x v%04x i%04x l%d\n",
 184                         ctrl->bRequestType, ctrl->bRequest,
 185                         w_value, w_index, w_length);
 186         }
 187
 188         /* respond with data transfer or status phase? */
 189         if (value >= 0) {
 190                 DBG(cdev, "Audio req%02x.%02x v%04x i%04x l%d\n",
 191                         ctrl->bRequestType, ctrl->bRequest,
 192                         w_value, w_index, w_length);
 193                 req->zero = 0;
 194                 req->length = value;
 195                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 196                 if (value < 0)
 197                         ERROR(cdev, "Audio response on err %d\n", value);
 198         }
 199
 200         /* device either stalls (value < 0) or reports success */
 201         return value;
 202 }
 203
 204 /*-------------------------------------------------------------------------*/
 205
 206 static int __init audio_do_config(struct usb_configuration *c)
 207 {
 208         /* FIXME alloc iConfiguration string, set it in c->strings */
 209
 210         if (gadget_is_otg(c->cdev->gadget)) {
 211                 c->descriptors = otg_desc;
 212                 c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 213         }
 214
 215         audio_bind_config(c);
 216
 217         return 0;
 218 }
 219
 220 static struct usb_configuration audio_config_driver = {
 221         .label                  = DRIVER_DESC,
 222         .bind                   = audio_do_config,
 223         .setup                  = audio_setup,
 224         .bConfigurationValue    = 1,
 225         /* .iConfiguration = DYNAMIC */
 226         .bmAttributes           = USB_CONFIG_ATT_SELFPOWER,
 227 };
 228
 229 /*-------------------------------------------------------------------------*/
 230
 231 static int __init audio_bind(struct usb_composite_dev *cdev)
 232 {
 233         int                     gcnum;
 234         int                     status;
 235
 236         gcnum = usb_gadget_controller_number(cdev->gadget);
 237         if (gcnum >= 0)
 238                 device_desc.bcdDevice = cpu_to_le16(0x0300 | gcnum);
 239         else {
 240                 ERROR(cdev, "controller '%s' not recognized; trying %s\n",
 241                         cdev->gadget->name,
 242                         audio_config_driver.label);
 243                 device_desc.bcdDevice =
 244                         __constant_cpu_to_le16(0x0300 | 0x0099);
 245         }
 246
 247         /* device descriptor strings: manufacturer, product */
 248         snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
 249                 init_utsname()->sysname, init_utsname()->release,
 250                 cdev->gadget->name);
 251         status = usb_string_id(cdev);
 252         if (status < 0)
 253                 goto fail;
 254         strings_dev[STRING_MANUFACTURER_IDX].id = status;
 255         device_desc.iManufacturer = status;
 256
 257         status = usb_string_id(cdev);
 258         if (status < 0)
 259                 goto fail;
 260         strings_dev[STRING_PRODUCT_IDX].id = status;
 261         device_desc.iProduct = status;
 262
 263         status = usb_add_config(cdev, &audio_config_driver);
 264         if (status < 0)
 265                 goto fail;
 266
 267         INFO(cdev, "%s, version: %s\n", DRIVER_DESC, DRIVER_VERSION);
 268         return 0;
 269
 270 fail:
 271         return status;
 272 }
 273
 274 static int __exit audio_unbind(struct usb_composite_dev *cdev)
 275 {
 276         return 0;
 277 }
 278
 279 static struct usb_composite_driver audio_driver = {
 280         .name           = "g_audio",
 281         .dev            = &device_desc,
 282         .strings        = audio_strings,
 283         .bind           = audio_bind,
 284         .unbind         = __exit_p(audio_unbind),
 285 };
 286
 287 static int __init init(void)
 288 {
 289         return usb_composite_register(&audio_driver);
 290 }
 291 module_init(init);
 292
 293 static void __exit cleanup(void)
 294 {
 295         usb_composite_unregister(&audio_driver);
 296 }
 297 module_exit(cleanup);
 298
 299 MODULE_DESCRIPTION(DRIVER_DESC);
 300 MODULE_AUTHOR("Bryan Wu <cooloney@kernel.org>");
 301 MODULE_LICENSE("GPL");
 302