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(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 */
108static 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 */
126static 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
144sees a stereo signal or not.  Pity. */
145static 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
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(radio->usbdev, v->bus_info, 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(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. */
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(&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(&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(&radio->hdl);
304	v4l2_device_unregister(&radio->v4l2_dev);
305	kfree(radio->transfer_buffer);
306	kfree(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(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
393err_reg_ctrl:
394	v4l2_ctrl_handler_free(&radio->hdl);
395	v4l2_device_unregister(v4l2_dev);
396err_reg_dev:
397	kfree(radio->transfer_buffer);
398	kfree(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