root/drivers/media/radio/dsbr100.c

DEFINITIONS

1. dsbr100_setfreq
2. dsbr100_start
3. dsbr100_stop
4. dsbr100_getstat
5. vidioc_querycap
6. vidioc_g_tuner
7. vidioc_s_tuner
8. vidioc_s_frequency
9. vidioc_g_frequency
10. usb_dsbr100_s_ctrl
11. usb_dsbr100_disconnect
12. usb_dsbr100_suspend
13. usb_dsbr100_resume
14. usb_dsbr100_release
15. usb_dsbr100_probe

   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         return 0;
 172 }
 173 
 174 static int vidioc_g_tuner(struct file *file, void *priv,
 175                                 struct v4l2_tuner *v)
 176 {
 177         struct dsbr100_device *radio = video_drvdata(file);
 178 
 179         if (v->index > 0)
 180                 return -EINVAL;
 181 
 182         dsbr100_getstat(radio);
 183         strscpy(v->name, "FM", sizeof(v->name));
 184         v->type = V4L2_TUNER_RADIO;
 185         v->rangelow = FREQ_MIN * FREQ_MUL;
 186         v->rangehigh = FREQ_MAX * FREQ_MUL;
 187         v->rxsubchans = radio->stereo ? V4L2_TUNER_SUB_STEREO :
 188                 V4L2_TUNER_SUB_MONO;
 189         v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO;
 190         v->audmode = V4L2_TUNER_MODE_STEREO;
 191         v->signal = radio->stereo ? 0xffff : 0;     /* We can't get the signal strength */
 192         return 0;
 193 }
 194 
 195 static int vidioc_s_tuner(struct file *file, void *priv,
 196                                 const struct v4l2_tuner *v)
 197 {
 198         return v->index ? -EINVAL : 0;
 199 }
 200 
 201 static int vidioc_s_frequency(struct file *file, void *priv,
 202                                 const struct v4l2_frequency *f)
 203 {
 204         struct dsbr100_device *radio = video_drvdata(file);
 205 
 206         if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
 207                 return -EINVAL;
 208 
 209         return dsbr100_setfreq(radio, clamp_t(unsigned, f->frequency,
 210                         FREQ_MIN * FREQ_MUL, FREQ_MAX * FREQ_MUL));
 211 }
 212 
 213 static int vidioc_g_frequency(struct file *file, void *priv,
 214                                 struct v4l2_frequency *f)
 215 {
 216         struct dsbr100_device *radio = video_drvdata(file);
 217 
 218         if (f->tuner)
 219                 return -EINVAL;
 220         f->type = V4L2_TUNER_RADIO;
 221         f->frequency = radio->curfreq;
 222         return 0;
 223 }
 224 
 225 static int usb_dsbr100_s_ctrl(struct v4l2_ctrl *ctrl)
 226 {
 227         struct dsbr100_device *radio =
 228                 container_of(ctrl->handler, struct dsbr100_device, hdl);
 229 
 230         switch (ctrl->id) {
 231         case V4L2_CID_AUDIO_MUTE:
 232                 radio->muted = ctrl->val;
 233                 return radio->muted ? dsbr100_stop(radio) : dsbr100_start(radio);
 234         }
 235         return -EINVAL;
 236 }
 237 
 238 
 239 /* USB subsystem interface begins here */
 240 
 241 /*
 242  * Handle unplugging of the device.
 243  * We call video_unregister_device in any case.
 244  * The last function called in this procedure is
 245  * usb_dsbr100_video_device_release
 246  */
 247 static void usb_dsbr100_disconnect(struct usb_interface *intf)
 248 {
 249         struct dsbr100_device *radio = usb_get_intfdata(intf);
 250 
 251         mutex_lock(&radio->v4l2_lock);
 252         /*
 253          * Disconnect is also called on unload, and in that case we need to
 254          * mute the device. This call will silently fail if it is called
 255          * after a physical disconnect.
 256          */
 257         usb_control_msg(radio->usbdev,
 258                 usb_rcvctrlpipe(radio->usbdev, 0),
 259                 DSB100_ONOFF,
 260                 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
 261                 0x00, 0x00, radio->transfer_buffer, 8, 300);
 262         usb_set_intfdata(intf, NULL);
 263         video_unregister_device(&radio->videodev);
 264         v4l2_device_disconnect(&radio->v4l2_dev);
 265         mutex_unlock(&radio->v4l2_lock);
 266         v4l2_device_put(&radio->v4l2_dev);
 267 }
 268 
 269 
 270 /* Suspend device - stop device. */
 271 static int usb_dsbr100_suspend(struct usb_interface *intf, pm_message_t message)
 272 {
 273         struct dsbr100_device *radio = usb_get_intfdata(intf);
 274 
 275         mutex_lock(&radio->v4l2_lock);
 276         if (!radio->muted && dsbr100_stop(radio) < 0)
 277                 dev_warn(&intf->dev, "dsbr100_stop failed\n");
 278         mutex_unlock(&radio->v4l2_lock);
 279 
 280         dev_info(&intf->dev, "going into suspend..\n");
 281         return 0;
 282 }
 283 
 284 /* Resume device - start device. */
 285 static int usb_dsbr100_resume(struct usb_interface *intf)
 286 {
 287         struct dsbr100_device *radio = usb_get_intfdata(intf);
 288 
 289         mutex_lock(&radio->v4l2_lock);
 290         if (!radio->muted && dsbr100_start(radio) < 0)
 291                 dev_warn(&intf->dev, "dsbr100_start failed\n");
 292         mutex_unlock(&radio->v4l2_lock);
 293 
 294         dev_info(&intf->dev, "coming out of suspend..\n");
 295         return 0;
 296 }
 297 
 298 /* free data structures */
 299 static void usb_dsbr100_release(struct v4l2_device *v4l2_dev)
 300 {
 301         struct dsbr100_device *radio = v4l2_dev_to_radio(v4l2_dev);
 302 
 303         v4l2_ctrl_handler_free(&radio->hdl);
 304         v4l2_device_unregister(&radio->v4l2_dev);
 305         kfree(radio->transfer_buffer);
 306         kfree(radio);
 307 }
 308 
 309 static const struct v4l2_ctrl_ops usb_dsbr100_ctrl_ops = {
 310         .s_ctrl = usb_dsbr100_s_ctrl,
 311 };
 312 
 313 /* File system interface */
 314 static const struct v4l2_file_operations usb_dsbr100_fops = {
 315         .owner          = THIS_MODULE,
 316         .unlocked_ioctl = video_ioctl2,
 317         .open           = v4l2_fh_open,
 318         .release        = v4l2_fh_release,
 319         .poll           = v4l2_ctrl_poll,
 320 };
 321 
 322 static const struct v4l2_ioctl_ops usb_dsbr100_ioctl_ops = {
 323         .vidioc_querycap    = vidioc_querycap,
 324         .vidioc_g_tuner     = vidioc_g_tuner,
 325         .vidioc_s_tuner     = vidioc_s_tuner,
 326         .vidioc_g_frequency = vidioc_g_frequency,
 327         .vidioc_s_frequency = vidioc_s_frequency,
 328         .vidioc_log_status  = v4l2_ctrl_log_status,
 329         .vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
 330         .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
 331 };
 332 
 333 /* check if the device is present and register with v4l and usb if it is */
 334 static int usb_dsbr100_probe(struct usb_interface *intf,
 335                                 const struct usb_device_id *id)
 336 {
 337         struct dsbr100_device *radio;
 338         struct v4l2_device *v4l2_dev;
 339         int retval;
 340 
 341         radio = kzalloc(sizeof(struct dsbr100_device), GFP_KERNEL);
 342 
 343         if (!radio)
 344                 return -ENOMEM;
 345 
 346         radio->transfer_buffer = kmalloc(TB_LEN, GFP_KERNEL);
 347 
 348         if (!(radio->transfer_buffer)) {
 349                 kfree(radio);
 350                 return -ENOMEM;
 351         }
 352 
 353         v4l2_dev = &radio->v4l2_dev;
 354         v4l2_dev->release = usb_dsbr100_release;
 355 
 356         retval = v4l2_device_register(&intf->dev, v4l2_dev);
 357         if (retval < 0) {
 358                 v4l2_err(v4l2_dev, "couldn't register v4l2_device\n");
 359                 goto err_reg_dev;
 360         }
 361 
 362         v4l2_ctrl_handler_init(&radio->hdl, 1);
 363         v4l2_ctrl_new_std(&radio->hdl, &usb_dsbr100_ctrl_ops,
 364                           V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
 365         if (radio->hdl.error) {
 366                 retval = radio->hdl.error;
 367                 v4l2_err(v4l2_dev, "couldn't register control\n");
 368                 goto err_reg_ctrl;
 369         }
 370         mutex_init(&radio->v4l2_lock);
 371         strscpy(radio->videodev.name, v4l2_dev->name,
 372                 sizeof(radio->videodev.name));
 373         radio->videodev.v4l2_dev = v4l2_dev;
 374         radio->videodev.fops = &usb_dsbr100_fops;
 375         radio->videodev.ioctl_ops = &usb_dsbr100_ioctl_ops;
 376         radio->videodev.release = video_device_release_empty;
 377         radio->videodev.lock = &radio->v4l2_lock;
 378         radio->videodev.ctrl_handler = &radio->hdl;
 379         radio->videodev.device_caps = V4L2_CAP_RADIO | V4L2_CAP_TUNER;
 380 
 381         radio->usbdev = interface_to_usbdev(intf);
 382         radio->curfreq = FREQ_MIN * FREQ_MUL;
 383         radio->muted = true;
 384 
 385         video_set_drvdata(&radio->videodev, radio);
 386         usb_set_intfdata(intf, radio);
 387 
 388         retval = video_register_device(&radio->videodev, VFL_TYPE_RADIO, radio_nr);
 389         if (retval == 0)
 390                 return 0;
 391         v4l2_err(v4l2_dev, "couldn't register video device\n");
 392 
 393 err_reg_ctrl:
 394         v4l2_ctrl_handler_free(&radio->hdl);
 395         v4l2_device_unregister(v4l2_dev);
 396 err_reg_dev:
 397         kfree(radio->transfer_buffer);
 398         kfree(radio);
 399         return retval;
 400 }
 401 
 402 static const struct usb_device_id usb_dsbr100_device_table[] = {
 403         { USB_DEVICE(DSB100_VENDOR, DSB100_PRODUCT) },
 404         { }                                             /* Terminating entry */
 405 };
 406 
 407 MODULE_DEVICE_TABLE(usb, usb_dsbr100_device_table);
 408 
 409 /* USB subsystem interface */
 410 static struct usb_driver usb_dsbr100_driver = {
 411         .name                   = "dsbr100",
 412         .probe                  = usb_dsbr100_probe,
 413         .disconnect             = usb_dsbr100_disconnect,
 414         .id_table               = usb_dsbr100_device_table,
 415         .suspend                = usb_dsbr100_suspend,
 416         .resume                 = usb_dsbr100_resume,
 417         .reset_resume           = usb_dsbr100_resume,
 418 };
 419 
 420 module_usb_driver(usb_dsbr100_driver);