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); 421