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); 422