drivers/media/radio/dsbr100.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* A driver for the D-Link DSB-R100 USB radio and Gemtek USB Radio 21.
   3  * The device plugs into both the USB and an analog audio input, so this thing
   4  * only deals with initialisation and frequency setting, the
   5  * audio data has to be handled by a sound driver.
   6  *
   7  * Major issue: I can't find out where the device reports the signal
   8  * strength, and indeed the windows software appearantly just looks
   9  * at the stereo indicator as well.  So, scanning will only find
  10  * stereo stations.  Sad, but I can't help it.
  11  *
  12  * Also, the windows program sends oodles of messages over to the
  13  * device, and I couldn't figure out their meaning.  My suspicion
  14  * is that they don't have any:-)
  15  *
  16  * You might find some interesting stuff about this module at
  17  * http://unimut.fsk.uni-heidelberg.de/unimut/demi/dsbr
  18  *
  19  * Fully tested with the Keene USB FM Transmitter and the v4l2-compliance tool.
  20  *
  21  * Copyright (c) 2000 Markus Demleitner <msdemlei@cl.uni-heidelberg.de>
  22 */
  23
  24 #include <linux/kernel.h>
  25 #include <linux/module.h>
  26 #include <linux/init.h>
  27 #include <linux/slab.h>
  28 #include <linux/input.h>
  29 #include <linux/videodev2.h>
  30 #include <linux/usb.h>
  31 #include <media/v4l2-device.h>
  32 #include <media/v4l2-ioctl.h>
  33 #include <media/v4l2-ctrls.h>
  34 #include <media/v4l2-event.h>
  35
  36 /*
  37  * Version Information
  38  */
  39 MODULE_AUTHOR("Markus Demleitner <msdemlei@tucana.harvard.edu>");
  40 MODULE_DESCRIPTION("D-Link DSB-R100 USB FM radio driver");
  41 MODULE_LICENSE("GPL");
  42 MODULE_VERSION("1.1.0");
  43
  44 #define DSB100_VENDOR 0x04b4
  45 #define DSB100_PRODUCT 0x1002
  46
  47 /* Commands the device appears to understand */
  48 #define DSB100_TUNE 1
  49 #define DSB100_ONOFF 2
  50
  51 #define TB_LEN 16
  52
  53 /* Frequency limits in MHz -- these are European values.  For Japanese
  54 devices, that would be 76 and 91.  */
  55 #define FREQ_MIN  87.5
  56 #define FREQ_MAX 108.0
  57 #define FREQ_MUL 16000
  58
  59 #define v4l2_dev_to_radio(d) container_of(d, struct dsbr100_device, v4l2_dev)
  60
  61 static int radio_nr = -1;
  62 module_param(radio_nr, int, 0);
  63
  64 /* Data for one (physical) device */
  65 struct dsbr100_device {
  66         struct usb_device *usbdev;
  67         struct video_device videodev;
  68         struct v4l2_device v4l2_dev;
  69         struct v4l2_ctrl_handler hdl;
  70
  71         u8 *transfer_buffer;
  72         struct mutex v4l2_lock;
  73         int curfreq;
  74         bool stereo;
  75         bool muted;
  76 };
  77
  78 /* Low-level device interface begins here */
  79
  80 /* set a frequency, freq is defined by v4l's TUNER_LOW, i.e. 1/16th kHz */
  81 static int dsbr100_setfreq(struct dsbr100_device *radio, unsigned freq)
  82 {
  83         unsigned f = (freq / 16 * 80) / 1000 + 856;
  84         int retval = 0;
  85
  86         if (!radio->muted) {
  87                 retval = usb_control_msg(radio->usbdev,
  88                                 usb_rcvctrlpipe(radio->usbdev, 0),
  89                                 DSB100_TUNE,
  90                                 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
  91                                 (f >> 8) & 0x00ff, f & 0xff,
  92                                 radio->transfer_buffer, 8, 300);
  93                 if (retval >= 0)
  94                         mdelay(1);
  95         }
  96
  97         if (retval >= 0) {
  98                 radio->curfreq = freq;
  99                 return 0;
 100         }
 101         dev_err(&radio->usbdev->dev,
 102                 "%s - usb_control_msg returned %i, request %i\n",
 103                         __func__, retval, DSB100_TUNE);
 104         return retval;
 105 }
 106
 107 /* switch on radio */
 108 static int dsbr100_start(struct dsbr100_device *radio)
 109 {
 110         int retval = usb_control_msg(radio->usbdev,
 111                 usb_rcvctrlpipe(radio->usbdev, 0),
 112                 DSB100_ONOFF,
 113                 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
 114                 0x01, 0x00, radio->transfer_buffer, 8, 300);
 115
 116         if (retval >= 0)
 117                 return dsbr100_setfreq(radio, radio->curfreq);
 118         dev_err(&radio->usbdev->dev,
 119                 "%s - usb_control_msg returned %i, request %i\n",
 120                         __func__, retval, DSB100_ONOFF);
 121         return retval;
 122
 123 }
 124
 125 /* switch off radio */
 126 static int dsbr100_stop(struct dsbr100_device *radio)
 127 {
 128         int retval = usb_control_msg(radio->usbdev,
 129                 usb_rcvctrlpipe(radio->usbdev, 0),
 130                 DSB100_ONOFF,
 131                 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
 132                 0x00, 0x00, radio->transfer_buffer, 8, 300);
 133
 134         if (retval >= 0)
 135                 return 0;
 136         dev_err(&radio->usbdev->dev,
 137                 "%s - usb_control_msg returned %i, request %i\n",
 138                         __func__, retval, DSB100_ONOFF);
 139         return retval;
 140
 141 }
 142
 143 /* return the device status.  This is, in effect, just whether it
 144 sees a stereo signal or not.  Pity. */
 145 static void dsbr100_getstat(struct dsbr100_device *radio)
 146 {
 147         int retval = usb_control_msg(radio->usbdev,
 148                 usb_rcvctrlpipe(radio->usbdev, 0),
 149                 USB_REQ_GET_STATUS,
 150                 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
 151                 0x00, 0x24, radio->transfer_buffer, 8, 300);
 152
 153         if (retval < 0) {
 154                 radio->stereo = false;
 155                 dev_err(&radio->usbdev->dev,
 156                         "%s - usb_control_msg returned %i, request %i\n",
 157                                 __func__, retval, USB_REQ_GET_STATUS);
 158         } else {
 159                 radio->stereo = !(radio->transfer_buffer[0] & 0x01);
 160         }
 161 }
 162
 163 static int vidioc_querycap(struct file *file, void *priv,
 164                                         struct v4l2_capability *v)
 165 {
 166         struct dsbr100_device *radio = video_drvdata(file);
 167
 168         strscpy(v->driver, "dsbr100", sizeof(v->driver));
 169         strscpy(v->card, "D-Link R-100 USB FM Radio", sizeof(v->card));
 170         usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
 171         v->device_caps = V4L2_CAP_RADIO | V4L2_CAP_TUNER;
 172         v->capabilities = v->device_caps | V4L2_CAP_DEVICE_CAPS;
 173         return 0;
 174 }
 175
 176 static int vidioc_g_tuner(struct file *file, void *priv,
 177                                 struct v4l2_tuner *v)
 178 {
 179         struct dsbr100_device *radio = video_drvdata(file);
 180
 181         if (v->index > 0)
 182                 return -EINVAL;
 183
 184         dsbr100_getstat(radio);
 185         strscpy(v->name, "FM", sizeof(v->name));
 186         v->type = V4L2_TUNER_RADIO;
 187         v->rangelow = FREQ_MIN * FREQ_MUL;
 188         v->rangehigh = FREQ_MAX * FREQ_MUL;
 189         v->rxsubchans = radio->stereo ? V4L2_TUNER_SUB_STEREO :
 190                 V4L2_TUNER_SUB_MONO;
 191         v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO;
 192         v->audmode = V4L2_TUNER_MODE_STEREO;
 193         v->signal = radio->stereo ? 0xffff : 0;     /* We can't get the signal strength */
 194         return 0;
 195 }
 196
 197 static int vidioc_s_tuner(struct file *file, void *priv,
 198                                 const struct v4l2_tuner *v)
 199 {
 200         return v->index ? -EINVAL : 0;
 201 }
 202
 203 static int vidioc_s_frequency(struct file *file, void *priv,
 204                                 const struct v4l2_frequency *f)
 205 {
 206         struct dsbr100_device *radio = video_drvdata(file);
 207
 208         if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
 209                 return -EINVAL;
 210
 211         return dsbr100_setfreq(radio, clamp_t(unsigned, f->frequency,
 212                         FREQ_MIN * FREQ_MUL, FREQ_MAX * FREQ_MUL));
 213 }
 214
 215 static int vidioc_g_frequency(struct file *file, void *priv,
 216                                 struct v4l2_frequency *f)
 217 {
 218         struct dsbr100_device *radio = video_drvdata(file);
 219
 220         if (f->tuner)
 221                 return -EINVAL;
 222         f->type = V4L2_TUNER_RADIO;
 223         f->frequency = radio->curfreq;
 224         return 0;
 225 }
 226
 227 static int usb_dsbr100_s_ctrl(struct v4l2_ctrl *ctrl)
 228 {
 229         struct dsbr100_device *radio =
 230                 container_of(ctrl->handler, struct dsbr100_device, hdl);
 231
 232         switch (ctrl->id) {
 233         case V4L2_CID_AUDIO_MUTE:
 234                 radio->muted = ctrl->val;
 235                 return radio->muted ? dsbr100_stop(radio) : dsbr100_start(radio);
 236         }
 237         return -EINVAL;
 238 }
 239
 240
 241 /* USB subsystem interface begins here */
 242
 243 /*
 244  * Handle unplugging of the device.
 245  * We call video_unregister_device in any case.
 246  * The last function called in this procedure is
 247  * usb_dsbr100_video_device_release
 248  */
 249 static void usb_dsbr100_disconnect(struct usb_interface *intf)
 250 {
 251         struct dsbr100_device *radio = usb_get_intfdata(intf);
 252
 253         mutex_lock(&radio->v4l2_lock);
 254         /*
 255          * Disconnect is also called on unload, and in that case we need to
 256          * mute the device. This call will silently fail if it is called
 257          * after a physical disconnect.
 258          */
 259         usb_control_msg(radio->usbdev,
 260                 usb_rcvctrlpipe(radio->usbdev, 0),
 261                 DSB100_ONOFF,
 262                 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
 263                 0x00, 0x00, radio->transfer_buffer, 8, 300);
 264         usb_set_intfdata(intf, NULL);
 265         video_unregister_device(&radio->videodev);
 266         v4l2_device_disconnect(&radio->v4l2_dev);
 267         mutex_unlock(&radio->v4l2_lock);
 268         v4l2_device_put(&radio->v4l2_dev);
 269 }
 270
 271
 272 /* Suspend device - stop device. */
 273 static int usb_dsbr100_suspend(struct usb_interface *intf, pm_message_t message)
 274 {
 275         struct dsbr100_device *radio = usb_get_intfdata(intf);
 276
 277         mutex_lock(&radio->v4l2_lock);
 278         if (!radio->muted && dsbr100_stop(radio) < 0)
 279                 dev_warn(&intf->dev, "dsbr100_stop failed\n");
 280         mutex_unlock(&radio->v4l2_lock);
 281
 282         dev_info(&intf->dev, "going into suspend..\n");
 283         return 0;
 284 }
 285
 286 /* Resume device - start device. */
 287 static int usb_dsbr100_resume(struct usb_interface *intf)
 288 {
 289         struct dsbr100_device *radio = usb_get_intfdata(intf);
 290
 291         mutex_lock(&radio->v4l2_lock);
 292         if (!radio->muted && dsbr100_start(radio) < 0)
 293                 dev_warn(&intf->dev, "dsbr100_start failed\n");
 294         mutex_unlock(&radio->v4l2_lock);
 295
 296         dev_info(&intf->dev, "coming out of suspend..\n");
 297         return 0;
 298 }
 299
 300 /* free data structures */
 301 static void usb_dsbr100_release(struct v4l2_device *v4l2_dev)
 302 {
 303         struct dsbr100_device *radio = v4l2_dev_to_radio(v4l2_dev);
 304
 305         v4l2_ctrl_handler_free(&radio->hdl);
 306         v4l2_device_unregister(&radio->v4l2_dev);
 307         kfree(radio->transfer_buffer);
 308         kfree(radio);
 309 }
 310
 311 static const struct v4l2_ctrl_ops usb_dsbr100_ctrl_ops = {
 312         .s_ctrl = usb_dsbr100_s_ctrl,
 313 };
 314
 315 /* File system interface */
 316 static const struct v4l2_file_operations usb_dsbr100_fops = {
 317         .owner          = THIS_MODULE,
 318         .unlocked_ioctl = video_ioctl2,
 319         .open           = v4l2_fh_open,
 320         .release        = v4l2_fh_release,
 321         .poll           = v4l2_ctrl_poll,
 322 };
 323
 324 static const struct v4l2_ioctl_ops usb_dsbr100_ioctl_ops = {
 325         .vidioc_querycap    = vidioc_querycap,
 326         .vidioc_g_tuner     = vidioc_g_tuner,
 327         .vidioc_s_tuner     = vidioc_s_tuner,
 328         .vidioc_g_frequency = vidioc_g_frequency,
 329         .vidioc_s_frequency = vidioc_s_frequency,
 330         .vidioc_log_status  = v4l2_ctrl_log_status,
 331         .vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
 332         .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
 333 };
 334
 335 /* check if the device is present and register with v4l and usb if it is */
 336 static int usb_dsbr100_probe(struct usb_interface *intf,
 337                                 const struct usb_device_id *id)
 338 {
 339         struct dsbr100_device *radio;
 340         struct v4l2_device *v4l2_dev;
 341         int retval;
 342
 343         radio = kzalloc(sizeof(struct dsbr100_device), GFP_KERNEL);
 344
 345         if (!radio)
 346                 return -ENOMEM;
 347
 348         radio->transfer_buffer = kmalloc(TB_LEN, GFP_KERNEL);
 349
 350         if (!(radio->transfer_buffer)) {
 351                 kfree(radio);
 352                 return -ENOMEM;
 353         }
 354
 355         v4l2_dev = &radio->v4l2_dev;
 356         v4l2_dev->release = usb_dsbr100_release;
 357
 358         retval = v4l2_device_register(&intf->dev, v4l2_dev);
 359         if (retval < 0) {
 360                 v4l2_err(v4l2_dev, "couldn't register v4l2_device\n");
 361                 goto err_reg_dev;
 362         }
 363
 364         v4l2_ctrl_handler_init(&radio->hdl, 1);
 365         v4l2_ctrl_new_std(&radio->hdl, &usb_dsbr100_ctrl_ops,
 366                           V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
 367         if (radio->hdl.error) {
 368                 retval = radio->hdl.error;
 369                 v4l2_err(v4l2_dev, "couldn't register control\n");
 370                 goto err_reg_ctrl;
 371         }
 372         mutex_init(&radio->v4l2_lock);
 373         strscpy(radio->videodev.name, v4l2_dev->name,
 374                 sizeof(radio->videodev.name));
 375         radio->videodev.v4l2_dev = v4l2_dev;
 376         radio->videodev.fops = &usb_dsbr100_fops;
 377         radio->videodev.ioctl_ops = &usb_dsbr100_ioctl_ops;
 378         radio->videodev.release = video_device_release_empty;
 379         radio->videodev.lock = &radio->v4l2_lock;
 380         radio->videodev.ctrl_handler = &radio->hdl;
 381
 382         radio->usbdev = interface_to_usbdev(intf);
 383         radio->curfreq = FREQ_MIN * FREQ_MUL;
 384         radio->muted = true;
 385
 386         video_set_drvdata(&radio->videodev, radio);
 387         usb_set_intfdata(intf, radio);
 388
 389         retval = video_register_device(&radio->videodev, VFL_TYPE_RADIO, radio_nr);
 390         if (retval == 0)
 391                 return 0;
 392         v4l2_err(v4l2_dev, "couldn't register video device\n");
 393
 394 err_reg_ctrl:
 395         v4l2_ctrl_handler_free(&radio->hdl);
 396         v4l2_device_unregister(v4l2_dev);
 397 err_reg_dev:
 398         kfree(radio->transfer_buffer);
 399         kfree(radio);
 400         return retval;
 401 }
 402
 403 static const struct usb_device_id usb_dsbr100_device_table[] = {
 404         { USB_DEVICE(DSB100_VENDOR, DSB100_PRODUCT) },
 405         { }                                             /* Terminating entry */
 406 };
 407
 408 MODULE_DEVICE_TABLE(usb, usb_dsbr100_device_table);
 409
 410 /* USB subsystem interface */
 411 static struct usb_driver usb_dsbr100_driver = {
 412         .name                   = "dsbr100",
 413         .probe                  = usb_dsbr100_probe,
 414         .disconnect             = usb_dsbr100_disconnect,
 415         .id_table               = usb_dsbr100_device_table,
 416         .suspend                = usb_dsbr100_suspend,
 417         .resume                 = usb_dsbr100_resume,
 418         .reset_resume           = usb_dsbr100_resume,
 419 };
 420
 421 module_usb_driver(usb_dsbr100_driver);