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 */
39MODULE_AUTHOR("Markus Demleitner <msdemlei@tucana.harvard.edu>");
40MODULE_DESCRIPTION("D-Link DSB-R100 USB FM radio driver");
41MODULE_LICENSE("GPL");
42MODULE_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
54devices, 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
61static int radio_nr = -1;
62module_param(radio_nr, int, 0);
63
64/* Data for one (physical) device */
65struct 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 */
81static 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(dev: radio->usbdev,
88 usb_rcvctrlpipe(radio->usbdev, 0),
89 DSB100_TUNE,
90 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
91 value: (f >> 8) & 0x00ff, index: f & 0xff,
92 data: radio->transfer_buffer, size: 8, timeout: 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 */
108static int dsbr100_start(struct dsbr100_device *radio)
109{
110 int retval = usb_control_msg(dev: radio->usbdev,
111 usb_rcvctrlpipe(radio->usbdev, 0),
112 DSB100_ONOFF,
113 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
114 value: 0x01, index: 0x00, data: radio->transfer_buffer, size: 8, timeout: 300);
115
116 if (retval >= 0)
117 return dsbr100_setfreq(radio, freq: 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 */
126static int dsbr100_stop(struct dsbr100_device *radio)
127{
128 int retval = usb_control_msg(dev: radio->usbdev,
129 usb_rcvctrlpipe(radio->usbdev, 0),
130 DSB100_ONOFF,
131 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
132 value: 0x00, index: 0x00, data: radio->transfer_buffer, size: 8, timeout: 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
144sees a stereo signal or not. Pity. */
145static void dsbr100_getstat(struct dsbr100_device *radio)
146{
147 int retval = usb_control_msg(dev: radio->usbdev,
148 usb_rcvctrlpipe(radio->usbdev, 0),
149 USB_REQ_GET_STATUS,
150 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
151 value: 0x00, index: 0x24, data: radio->transfer_buffer, size: 8, timeout: 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
163static 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(dev: radio->usbdev, buf: v->bus_info, size: sizeof(v->bus_info));
171 return 0;
172}
173
174static 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
195static int vidioc_s_tuner(struct file *file, void *priv,
196 const struct v4l2_tuner *v)
197{
198 return v->index ? -EINVAL : 0;
199}
200
201static 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
213static 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
225static 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 */
247static 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(dev: radio->usbdev,
258 usb_rcvctrlpipe(radio->usbdev, 0),
259 DSB100_ONOFF,
260 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
261 value: 0x00, index: 0x00, data: radio->transfer_buffer, size: 8, timeout: 300);
262 usb_set_intfdata(intf, NULL);
263 video_unregister_device(vdev: &radio->videodev);
264 v4l2_device_disconnect(v4l2_dev: &radio->v4l2_dev);
265 mutex_unlock(lock: &radio->v4l2_lock);
266 v4l2_device_put(v4l2_dev: &radio->v4l2_dev);
267}
268
269
270/* Suspend device - stop device. */
271static 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(lock: &radio->v4l2_lock);
279
280 dev_info(&intf->dev, "going into suspend..\n");
281 return 0;
282}
283
284/* Resume device - start device. */
285static 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(lock: &radio->v4l2_lock);
293
294 dev_info(&intf->dev, "coming out of suspend..\n");
295 return 0;
296}
297
298/* free data structures */
299static 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(hdl: &radio->hdl);
304 v4l2_device_unregister(v4l2_dev: &radio->v4l2_dev);
305 kfree(objp: radio->transfer_buffer);
306 kfree(objp: radio);
307}
308
309static const struct v4l2_ctrl_ops usb_dsbr100_ctrl_ops = {
310 .s_ctrl = usb_dsbr100_s_ctrl,
311};
312
313/* File system interface */
314static 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
322static 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 */
334static 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(size: 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(objp: 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(dev: &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(hdl: &radio->hdl, ops: &usb_dsbr100_ctrl_ops,
364 V4L2_CID_AUDIO_MUTE, min: 0, max: 1, step: 1, def: 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(vdev: &radio->videodev, data: radio);
386 usb_set_intfdata(intf, data: radio);
387
388 retval = video_register_device(vdev: &radio->videodev, type: VFL_TYPE_RADIO, nr: radio_nr);
389 if (retval == 0)
390 return 0;
391 v4l2_err(v4l2_dev, "couldn't register video device\n");
392
393err_reg_ctrl:
394 v4l2_ctrl_handler_free(hdl: &radio->hdl);
395 v4l2_device_unregister(v4l2_dev);
396err_reg_dev:
397 kfree(objp: radio->transfer_buffer);
398 kfree(objp: radio);
399 return retval;
400}
401
402static const struct usb_device_id usb_dsbr100_device_table[] = {
403 { USB_DEVICE(DSB100_VENDOR, DSB100_PRODUCT) },
404 { } /* Terminating entry */
405};
406
407MODULE_DEVICE_TABLE(usb, usb_dsbr100_device_table);
408
409/* USB subsystem interface */
410static 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
420module_usb_driver(usb_dsbr100_driver);
421

source code of linux/drivers/media/radio/dsbr100.c