1/* A driver for the D-Link DSB-R100 USB radio and Gemtek USB Radio 21.
2 * The device plugs into both the USB and an analog audio input, so this thing
3 * only deals with initialisation and frequency setting, the
4 * audio data has to be handled by a sound driver.
5 *
6 * Major issue: I can't find out where the device reports the signal
7 * strength, and indeed the windows software appearantly just looks
8 * at the stereo indicator as well.  So, scanning will only find
9 * stereo stations.  Sad, but I can't help it.
10 *
11 * Also, the windows program sends oodles of messages over to the
12 * device, and I couldn't figure out their meaning.  My suspicion
13 * is that they don't have any:-)
14 *
15 * You might find some interesting stuff about this module at
16 * http://unimut.fsk.uni-heidelberg.de/unimut/demi/dsbr
17 *
18 * Fully tested with the Keene USB FM Transmitter and the v4l2-compliance tool.
19 *
20 * Copyright (c) 2000 Markus Demleitner <msdemlei@cl.uni-heidelberg.de>
21 *
22 * This program is free software; you can redistribute it and/or modify
23 * it under the terms of the GNU General Public License as published by
24 * the Free Software Foundation; either version 2 of the License, or
25 * (at your option) any later version.
26 *
27 * This program is distributed in the hope that it will be useful,
28 * but WITHOUT ANY WARRANTY; without even the implied warranty of
29 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
30 * GNU General Public License for more details.
31 *
32 * You should have received a copy of the GNU General Public License
33 * along with this program; if not, write to the Free Software
34 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
35*/
36
37#include <linux/kernel.h>
38#include <linux/module.h>
39#include <linux/init.h>
40#include <linux/slab.h>
41#include <linux/input.h>
42#include <linux/videodev2.h>
43#include <linux/usb.h>
44#include <media/v4l2-device.h>
45#include <media/v4l2-ioctl.h>
46#include <media/v4l2-ctrls.h>
47#include <media/v4l2-event.h>
48
49/*
50 * Version Information
51 */
52MODULE_AUTHOR("Markus Demleitner <msdemlei@tucana.harvard.edu>");
53MODULE_DESCRIPTION("D-Link DSB-R100 USB FM radio driver");
54MODULE_LICENSE("GPL");
55MODULE_VERSION("1.1.0");
56
57#define DSB100_VENDOR 0x04b4
58#define DSB100_PRODUCT 0x1002
59
60/* Commands the device appears to understand */
61#define DSB100_TUNE 1
62#define DSB100_ONOFF 2
63
64#define TB_LEN 16
65
66/* Frequency limits in MHz -- these are European values.  For Japanese
67devices, that would be 76 and 91.  */
68#define FREQ_MIN  87.5
69#define FREQ_MAX 108.0
70#define FREQ_MUL 16000
71
72#define v4l2_dev_to_radio(d) container_of(d, struct dsbr100_device, v4l2_dev)
73
74static int radio_nr = -1;
75module_param(radio_nr, int, 0);
76
77/* Data for one (physical) device */
78struct dsbr100_device {
79	struct usb_device *usbdev;
80	struct video_device videodev;
81	struct v4l2_device v4l2_dev;
82	struct v4l2_ctrl_handler hdl;
83
84	u8 *transfer_buffer;
85	struct mutex v4l2_lock;
86	int curfreq;
87	bool stereo;
88	bool muted;
89};
90
91/* Low-level device interface begins here */
92
93/* set a frequency, freq is defined by v4l's TUNER_LOW, i.e. 1/16th kHz */
94static int dsbr100_setfreq(struct dsbr100_device *radio, unsigned freq)
95{
96	unsigned f = (freq / 16 * 80) / 1000 + 856;
97	int retval = 0;
98
99	if (!radio->muted) {
100		retval = usb_control_msg(radio->usbdev,
101				usb_rcvctrlpipe(radio->usbdev, 0),
102				DSB100_TUNE,
103				USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
104				(f >> 8) & 0x00ff, f & 0xff,
105				radio->transfer_buffer, 8, 300);
106		if (retval >= 0)
107			mdelay(1);
108	}
109
110	if (retval >= 0) {
111		radio->curfreq = freq;
112		return 0;
113	}
114	dev_err(&radio->usbdev->dev,
115		"%s - usb_control_msg returned %i, request %i\n",
116			__func__, retval, DSB100_TUNE);
117	return retval;
118}
119
120/* switch on radio */
121static int dsbr100_start(struct dsbr100_device *radio)
122{
123	int retval = usb_control_msg(radio->usbdev,
124		usb_rcvctrlpipe(radio->usbdev, 0),
125		DSB100_ONOFF,
126		USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
127		0x01, 0x00, radio->transfer_buffer, 8, 300);
128
129	if (retval >= 0)
130		return dsbr100_setfreq(radio, radio->curfreq);
131	dev_err(&radio->usbdev->dev,
132		"%s - usb_control_msg returned %i, request %i\n",
133			__func__, retval, DSB100_ONOFF);
134	return retval;
135
136}
137
138/* switch off radio */
139static int dsbr100_stop(struct dsbr100_device *radio)
140{
141	int retval = usb_control_msg(radio->usbdev,
142		usb_rcvctrlpipe(radio->usbdev, 0),
143		DSB100_ONOFF,
144		USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
145		0x00, 0x00, radio->transfer_buffer, 8, 300);
146
147	if (retval >= 0)
148		return 0;
149	dev_err(&radio->usbdev->dev,
150		"%s - usb_control_msg returned %i, request %i\n",
151			__func__, retval, DSB100_ONOFF);
152	return retval;
153
154}
155
156/* return the device status.  This is, in effect, just whether it
157sees a stereo signal or not.  Pity. */
158static void dsbr100_getstat(struct dsbr100_device *radio)
159{
160	int retval = usb_control_msg(radio->usbdev,
161		usb_rcvctrlpipe(radio->usbdev, 0),
162		USB_REQ_GET_STATUS,
163		USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
164		0x00, 0x24, radio->transfer_buffer, 8, 300);
165
166	if (retval < 0) {
167		radio->stereo = false;
168		dev_err(&radio->usbdev->dev,
169			"%s - usb_control_msg returned %i, request %i\n",
170				__func__, retval, USB_REQ_GET_STATUS);
171	} else {
172		radio->stereo = !(radio->transfer_buffer[0] & 0x01);
173	}
174}
175
176static int vidioc_querycap(struct file *file, void *priv,
177					struct v4l2_capability *v)
178{
179	struct dsbr100_device *radio = video_drvdata(file);
180
181	strlcpy(v->driver, "dsbr100", sizeof(v->driver));
182	strlcpy(v->card, "D-Link R-100 USB FM Radio", sizeof(v->card));
183	usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
184	v->device_caps = V4L2_CAP_RADIO | V4L2_CAP_TUNER;
185	v->capabilities = v->device_caps | V4L2_CAP_DEVICE_CAPS;
186	return 0;
187}
188
189static int vidioc_g_tuner(struct file *file, void *priv,
190				struct v4l2_tuner *v)
191{
192	struct dsbr100_device *radio = video_drvdata(file);
193
194	if (v->index > 0)
195		return -EINVAL;
196
197	dsbr100_getstat(radio);
198	strcpy(v->name, "FM");
199	v->type = V4L2_TUNER_RADIO;
200	v->rangelow = FREQ_MIN * FREQ_MUL;
201	v->rangehigh = FREQ_MAX * FREQ_MUL;
202	v->rxsubchans = radio->stereo ? V4L2_TUNER_SUB_STEREO :
203		V4L2_TUNER_SUB_MONO;
204	v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO;
205	v->audmode = V4L2_TUNER_MODE_STEREO;
206	v->signal = radio->stereo ? 0xffff : 0;     /* We can't get the signal strength */
207	return 0;
208}
209
210static int vidioc_s_tuner(struct file *file, void *priv,
211				const struct v4l2_tuner *v)
212{
213	return v->index ? -EINVAL : 0;
214}
215
216static int vidioc_s_frequency(struct file *file, void *priv,
217				const struct v4l2_frequency *f)
218{
219	struct dsbr100_device *radio = video_drvdata(file);
220
221	if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
222		return -EINVAL;
223
224	return dsbr100_setfreq(radio, clamp_t(unsigned, f->frequency,
225			FREQ_MIN * FREQ_MUL, FREQ_MAX * FREQ_MUL));
226}
227
228static int vidioc_g_frequency(struct file *file, void *priv,
229				struct v4l2_frequency *f)
230{
231	struct dsbr100_device *radio = video_drvdata(file);
232
233	if (f->tuner)
234		return -EINVAL;
235	f->type = V4L2_TUNER_RADIO;
236	f->frequency = radio->curfreq;
237	return 0;
238}
239
240static int usb_dsbr100_s_ctrl(struct v4l2_ctrl *ctrl)
241{
242	struct dsbr100_device *radio =
243		container_of(ctrl->handler, struct dsbr100_device, hdl);
244
245	switch (ctrl->id) {
246	case V4L2_CID_AUDIO_MUTE:
247		radio->muted = ctrl->val;
248		return radio->muted ? dsbr100_stop(radio) : dsbr100_start(radio);
249	}
250	return -EINVAL;
251}
252
253
254/* USB subsystem interface begins here */
255
256/*
257 * Handle unplugging of the device.
258 * We call video_unregister_device in any case.
259 * The last function called in this procedure is
260 * usb_dsbr100_video_device_release
261 */
262static void usb_dsbr100_disconnect(struct usb_interface *intf)
263{
264	struct dsbr100_device *radio = usb_get_intfdata(intf);
265
266	mutex_lock(&radio->v4l2_lock);
267	/*
268	 * Disconnect is also called on unload, and in that case we need to
269	 * mute the device. This call will silently fail if it is called
270	 * after a physical disconnect.
271	 */
272	usb_control_msg(radio->usbdev,
273		usb_rcvctrlpipe(radio->usbdev, 0),
274		DSB100_ONOFF,
275		USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
276		0x00, 0x00, radio->transfer_buffer, 8, 300);
277	usb_set_intfdata(intf, NULL);
278	video_unregister_device(&radio->videodev);
279	v4l2_device_disconnect(&radio->v4l2_dev);
280	mutex_unlock(&radio->v4l2_lock);
281	v4l2_device_put(&radio->v4l2_dev);
282}
283
284
285/* Suspend device - stop device. */
286static int usb_dsbr100_suspend(struct usb_interface *intf, pm_message_t message)
287{
288	struct dsbr100_device *radio = usb_get_intfdata(intf);
289
290	mutex_lock(&radio->v4l2_lock);
291	if (!radio->muted && dsbr100_stop(radio) < 0)
292		dev_warn(&intf->dev, "dsbr100_stop failed\n");
293	mutex_unlock(&radio->v4l2_lock);
294
295	dev_info(&intf->dev, "going into suspend..\n");
296	return 0;
297}
298
299/* Resume device - start device. */
300static int usb_dsbr100_resume(struct usb_interface *intf)
301{
302	struct dsbr100_device *radio = usb_get_intfdata(intf);
303
304	mutex_lock(&radio->v4l2_lock);
305	if (!radio->muted && dsbr100_start(radio) < 0)
306		dev_warn(&intf->dev, "dsbr100_start failed\n");
307	mutex_unlock(&radio->v4l2_lock);
308
309	dev_info(&intf->dev, "coming out of suspend..\n");
310	return 0;
311}
312
313/* free data structures */
314static void usb_dsbr100_release(struct v4l2_device *v4l2_dev)
315{
316	struct dsbr100_device *radio = v4l2_dev_to_radio(v4l2_dev);
317
318	v4l2_ctrl_handler_free(&radio->hdl);
319	v4l2_device_unregister(&radio->v4l2_dev);
320	kfree(radio->transfer_buffer);
321	kfree(radio);
322}
323
324static const struct v4l2_ctrl_ops usb_dsbr100_ctrl_ops = {
325	.s_ctrl = usb_dsbr100_s_ctrl,
326};
327
328/* File system interface */
329static const struct v4l2_file_operations usb_dsbr100_fops = {
330	.owner		= THIS_MODULE,
331	.unlocked_ioctl	= video_ioctl2,
332	.open           = v4l2_fh_open,
333	.release        = v4l2_fh_release,
334	.poll		= v4l2_ctrl_poll,
335};
336
337static const struct v4l2_ioctl_ops usb_dsbr100_ioctl_ops = {
338	.vidioc_querycap    = vidioc_querycap,
339	.vidioc_g_tuner     = vidioc_g_tuner,
340	.vidioc_s_tuner     = vidioc_s_tuner,
341	.vidioc_g_frequency = vidioc_g_frequency,
342	.vidioc_s_frequency = vidioc_s_frequency,
343	.vidioc_log_status  = v4l2_ctrl_log_status,
344	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
345	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
346};
347
348/* check if the device is present and register with v4l and usb if it is */
349static int usb_dsbr100_probe(struct usb_interface *intf,
350				const struct usb_device_id *id)
351{
352	struct dsbr100_device *radio;
353	struct v4l2_device *v4l2_dev;
354	int retval;
355
356	radio = kzalloc(sizeof(struct dsbr100_device), GFP_KERNEL);
357
358	if (!radio)
359		return -ENOMEM;
360
361	radio->transfer_buffer = kmalloc(TB_LEN, GFP_KERNEL);
362
363	if (!(radio->transfer_buffer)) {
364		kfree(radio);
365		return -ENOMEM;
366	}
367
368	v4l2_dev = &radio->v4l2_dev;
369	v4l2_dev->release = usb_dsbr100_release;
370
371	retval = v4l2_device_register(&intf->dev, v4l2_dev);
372	if (retval < 0) {
373		v4l2_err(v4l2_dev, "couldn't register v4l2_device\n");
374		goto err_reg_dev;
375	}
376
377	v4l2_ctrl_handler_init(&radio->hdl, 1);
378	v4l2_ctrl_new_std(&radio->hdl, &usb_dsbr100_ctrl_ops,
379			  V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
380	if (radio->hdl.error) {
381		retval = radio->hdl.error;
382		v4l2_err(v4l2_dev, "couldn't register control\n");
383		goto err_reg_ctrl;
384	}
385	mutex_init(&radio->v4l2_lock);
386	strlcpy(radio->videodev.name, v4l2_dev->name, sizeof(radio->videodev.name));
387	radio->videodev.v4l2_dev = v4l2_dev;
388	radio->videodev.fops = &usb_dsbr100_fops;
389	radio->videodev.ioctl_ops = &usb_dsbr100_ioctl_ops;
390	radio->videodev.release = video_device_release_empty;
391	radio->videodev.lock = &radio->v4l2_lock;
392	radio->videodev.ctrl_handler = &radio->hdl;
393
394	radio->usbdev = interface_to_usbdev(intf);
395	radio->curfreq = FREQ_MIN * FREQ_MUL;
396	radio->muted = true;
397
398	video_set_drvdata(&radio->videodev, radio);
399	usb_set_intfdata(intf, radio);
400
401	retval = video_register_device(&radio->videodev, VFL_TYPE_RADIO, radio_nr);
402	if (retval == 0)
403		return 0;
404	v4l2_err(v4l2_dev, "couldn't register video device\n");
405
406err_reg_ctrl:
407	v4l2_ctrl_handler_free(&radio->hdl);
408	v4l2_device_unregister(v4l2_dev);
409err_reg_dev:
410	kfree(radio->transfer_buffer);
411	kfree(radio);
412	return retval;
413}
414
415static struct usb_device_id usb_dsbr100_device_table[] = {
416	{ USB_DEVICE(DSB100_VENDOR, DSB100_PRODUCT) },
417	{ }						/* Terminating entry */
418};
419
420MODULE_DEVICE_TABLE(usb, usb_dsbr100_device_table);
421
422/* USB subsystem interface */
423static struct usb_driver usb_dsbr100_driver = {
424	.name			= "dsbr100",
425	.probe			= usb_dsbr100_probe,
426	.disconnect		= usb_dsbr100_disconnect,
427	.id_table		= usb_dsbr100_device_table,
428	.suspend		= usb_dsbr100_suspend,
429	.resume			= usb_dsbr100_resume,
430	.reset_resume		= usb_dsbr100_resume,
431};
432
433module_usb_driver(usb_dsbr100_driver);
434