xref: /openbmc/linux/drivers/media/radio/dsbr100.c (revision e83ce300)
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 
33 #include <linux/kernel.h>
34 #include <linux/module.h>
35 #include <linux/init.h>
36 #include <linux/slab.h>
37 #include <linux/input.h>
38 #include <linux/videodev2.h>
39 #include <linux/usb.h>
40 #include <media/v4l2-device.h>
41 #include <media/v4l2-ioctl.h>
42 #include <media/v4l2-ctrls.h>
43 #include <media/v4l2-event.h>
44 
45 /*
46  * Version Information
47  */
48 MODULE_AUTHOR("Markus Demleitner <msdemlei@tucana.harvard.edu>");
49 MODULE_DESCRIPTION("D-Link DSB-R100 USB FM radio driver");
50 MODULE_LICENSE("GPL");
51 MODULE_VERSION("1.1.0");
52 
53 #define DSB100_VENDOR 0x04b4
54 #define DSB100_PRODUCT 0x1002
55 
56 /* Commands the device appears to understand */
57 #define DSB100_TUNE 1
58 #define DSB100_ONOFF 2
59 
60 #define TB_LEN 16
61 
62 /* Frequency limits in MHz -- these are European values.  For Japanese
63 devices, that would be 76 and 91.  */
64 #define FREQ_MIN  87.5
65 #define FREQ_MAX 108.0
66 #define FREQ_MUL 16000
67 
68 #define v4l2_dev_to_radio(d) container_of(d, struct dsbr100_device, v4l2_dev)
69 
70 static int radio_nr = -1;
71 module_param(radio_nr, int, 0);
72 
73 /* Data for one (physical) device */
74 struct dsbr100_device {
75 	struct usb_device *usbdev;
76 	struct video_device videodev;
77 	struct v4l2_device v4l2_dev;
78 	struct v4l2_ctrl_handler hdl;
79 
80 	u8 *transfer_buffer;
81 	struct mutex v4l2_lock;
82 	int curfreq;
83 	bool stereo;
84 	bool muted;
85 };
86 
87 /* Low-level device interface begins here */
88 
89 /* set a frequency, freq is defined by v4l's TUNER_LOW, i.e. 1/16th kHz */
90 static int dsbr100_setfreq(struct dsbr100_device *radio, unsigned freq)
91 {
92 	unsigned f = (freq / 16 * 80) / 1000 + 856;
93 	int retval = 0;
94 
95 	if (!radio->muted) {
96 		retval = usb_control_msg(radio->usbdev,
97 				usb_rcvctrlpipe(radio->usbdev, 0),
98 				DSB100_TUNE,
99 				USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
100 				(f >> 8) & 0x00ff, f & 0xff,
101 				radio->transfer_buffer, 8, 300);
102 		if (retval >= 0)
103 			mdelay(1);
104 	}
105 
106 	if (retval >= 0) {
107 		radio->curfreq = freq;
108 		return 0;
109 	}
110 	dev_err(&radio->usbdev->dev,
111 		"%s - usb_control_msg returned %i, request %i\n",
112 			__func__, retval, DSB100_TUNE);
113 	return retval;
114 }
115 
116 /* switch on radio */
117 static int dsbr100_start(struct dsbr100_device *radio)
118 {
119 	int retval = usb_control_msg(radio->usbdev,
120 		usb_rcvctrlpipe(radio->usbdev, 0),
121 		DSB100_ONOFF,
122 		USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
123 		0x01, 0x00, radio->transfer_buffer, 8, 300);
124 
125 	if (retval >= 0)
126 		return dsbr100_setfreq(radio, radio->curfreq);
127 	dev_err(&radio->usbdev->dev,
128 		"%s - usb_control_msg returned %i, request %i\n",
129 			__func__, retval, DSB100_ONOFF);
130 	return retval;
131 
132 }
133 
134 /* switch off radio */
135 static int dsbr100_stop(struct dsbr100_device *radio)
136 {
137 	int retval = usb_control_msg(radio->usbdev,
138 		usb_rcvctrlpipe(radio->usbdev, 0),
139 		DSB100_ONOFF,
140 		USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
141 		0x00, 0x00, radio->transfer_buffer, 8, 300);
142 
143 	if (retval >= 0)
144 		return 0;
145 	dev_err(&radio->usbdev->dev,
146 		"%s - usb_control_msg returned %i, request %i\n",
147 			__func__, retval, DSB100_ONOFF);
148 	return retval;
149 
150 }
151 
152 /* return the device status.  This is, in effect, just whether it
153 sees a stereo signal or not.  Pity. */
154 static void dsbr100_getstat(struct dsbr100_device *radio)
155 {
156 	int retval = usb_control_msg(radio->usbdev,
157 		usb_rcvctrlpipe(radio->usbdev, 0),
158 		USB_REQ_GET_STATUS,
159 		USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
160 		0x00, 0x24, radio->transfer_buffer, 8, 300);
161 
162 	if (retval < 0) {
163 		radio->stereo = false;
164 		dev_err(&radio->usbdev->dev,
165 			"%s - usb_control_msg returned %i, request %i\n",
166 				__func__, retval, USB_REQ_GET_STATUS);
167 	} else {
168 		radio->stereo = !(radio->transfer_buffer[0] & 0x01);
169 	}
170 }
171 
172 static int vidioc_querycap(struct file *file, void *priv,
173 					struct v4l2_capability *v)
174 {
175 	struct dsbr100_device *radio = video_drvdata(file);
176 
177 	strscpy(v->driver, "dsbr100", sizeof(v->driver));
178 	strscpy(v->card, "D-Link R-100 USB FM Radio", sizeof(v->card));
179 	usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
180 	return 0;
181 }
182 
183 static int vidioc_g_tuner(struct file *file, void *priv,
184 				struct v4l2_tuner *v)
185 {
186 	struct dsbr100_device *radio = video_drvdata(file);
187 
188 	if (v->index > 0)
189 		return -EINVAL;
190 
191 	dsbr100_getstat(radio);
192 	strscpy(v->name, "FM", sizeof(v->name));
193 	v->type = V4L2_TUNER_RADIO;
194 	v->rangelow = FREQ_MIN * FREQ_MUL;
195 	v->rangehigh = FREQ_MAX * FREQ_MUL;
196 	v->rxsubchans = radio->stereo ? V4L2_TUNER_SUB_STEREO :
197 		V4L2_TUNER_SUB_MONO;
198 	v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO;
199 	v->audmode = V4L2_TUNER_MODE_STEREO;
200 	v->signal = radio->stereo ? 0xffff : 0;     /* We can't get the signal strength */
201 	return 0;
202 }
203 
204 static int vidioc_s_tuner(struct file *file, void *priv,
205 				const struct v4l2_tuner *v)
206 {
207 	return v->index ? -EINVAL : 0;
208 }
209 
210 static int vidioc_s_frequency(struct file *file, void *priv,
211 				const struct v4l2_frequency *f)
212 {
213 	struct dsbr100_device *radio = video_drvdata(file);
214 
215 	if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
216 		return -EINVAL;
217 
218 	return dsbr100_setfreq(radio, clamp_t(unsigned, f->frequency,
219 			FREQ_MIN * FREQ_MUL, FREQ_MAX * FREQ_MUL));
220 }
221 
222 static int vidioc_g_frequency(struct file *file, void *priv,
223 				struct v4l2_frequency *f)
224 {
225 	struct dsbr100_device *radio = video_drvdata(file);
226 
227 	if (f->tuner)
228 		return -EINVAL;
229 	f->type = V4L2_TUNER_RADIO;
230 	f->frequency = radio->curfreq;
231 	return 0;
232 }
233 
234 static int usb_dsbr100_s_ctrl(struct v4l2_ctrl *ctrl)
235 {
236 	struct dsbr100_device *radio =
237 		container_of(ctrl->handler, struct dsbr100_device, hdl);
238 
239 	switch (ctrl->id) {
240 	case V4L2_CID_AUDIO_MUTE:
241 		radio->muted = ctrl->val;
242 		return radio->muted ? dsbr100_stop(radio) : dsbr100_start(radio);
243 	}
244 	return -EINVAL;
245 }
246 
247 
248 /* USB subsystem interface begins here */
249 
250 /*
251  * Handle unplugging of the device.
252  * We call video_unregister_device in any case.
253  * The last function called in this procedure is
254  * usb_dsbr100_video_device_release
255  */
256 static void usb_dsbr100_disconnect(struct usb_interface *intf)
257 {
258 	struct dsbr100_device *radio = usb_get_intfdata(intf);
259 
260 	mutex_lock(&radio->v4l2_lock);
261 	/*
262 	 * Disconnect is also called on unload, and in that case we need to
263 	 * mute the device. This call will silently fail if it is called
264 	 * after a physical disconnect.
265 	 */
266 	usb_control_msg(radio->usbdev,
267 		usb_rcvctrlpipe(radio->usbdev, 0),
268 		DSB100_ONOFF,
269 		USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
270 		0x00, 0x00, radio->transfer_buffer, 8, 300);
271 	usb_set_intfdata(intf, NULL);
272 	video_unregister_device(&radio->videodev);
273 	v4l2_device_disconnect(&radio->v4l2_dev);
274 	mutex_unlock(&radio->v4l2_lock);
275 	v4l2_device_put(&radio->v4l2_dev);
276 }
277 
278 
279 /* Suspend device - stop device. */
280 static int usb_dsbr100_suspend(struct usb_interface *intf, pm_message_t message)
281 {
282 	struct dsbr100_device *radio = usb_get_intfdata(intf);
283 
284 	mutex_lock(&radio->v4l2_lock);
285 	if (!radio->muted && dsbr100_stop(radio) < 0)
286 		dev_warn(&intf->dev, "dsbr100_stop failed\n");
287 	mutex_unlock(&radio->v4l2_lock);
288 
289 	dev_info(&intf->dev, "going into suspend..\n");
290 	return 0;
291 }
292 
293 /* Resume device - start device. */
294 static int usb_dsbr100_resume(struct usb_interface *intf)
295 {
296 	struct dsbr100_device *radio = usb_get_intfdata(intf);
297 
298 	mutex_lock(&radio->v4l2_lock);
299 	if (!radio->muted && dsbr100_start(radio) < 0)
300 		dev_warn(&intf->dev, "dsbr100_start failed\n");
301 	mutex_unlock(&radio->v4l2_lock);
302 
303 	dev_info(&intf->dev, "coming out of suspend..\n");
304 	return 0;
305 }
306 
307 /* free data structures */
308 static void usb_dsbr100_release(struct v4l2_device *v4l2_dev)
309 {
310 	struct dsbr100_device *radio = v4l2_dev_to_radio(v4l2_dev);
311 
312 	v4l2_ctrl_handler_free(&radio->hdl);
313 	v4l2_device_unregister(&radio->v4l2_dev);
314 	kfree(radio->transfer_buffer);
315 	kfree(radio);
316 }
317 
318 static const struct v4l2_ctrl_ops usb_dsbr100_ctrl_ops = {
319 	.s_ctrl = usb_dsbr100_s_ctrl,
320 };
321 
322 /* File system interface */
323 static const struct v4l2_file_operations usb_dsbr100_fops = {
324 	.owner		= THIS_MODULE,
325 	.unlocked_ioctl	= video_ioctl2,
326 	.open           = v4l2_fh_open,
327 	.release        = v4l2_fh_release,
328 	.poll		= v4l2_ctrl_poll,
329 };
330 
331 static const struct v4l2_ioctl_ops usb_dsbr100_ioctl_ops = {
332 	.vidioc_querycap    = vidioc_querycap,
333 	.vidioc_g_tuner     = vidioc_g_tuner,
334 	.vidioc_s_tuner     = vidioc_s_tuner,
335 	.vidioc_g_frequency = vidioc_g_frequency,
336 	.vidioc_s_frequency = vidioc_s_frequency,
337 	.vidioc_log_status  = v4l2_ctrl_log_status,
338 	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
339 	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
340 };
341 
342 /* check if the device is present and register with v4l and usb if it is */
343 static int usb_dsbr100_probe(struct usb_interface *intf,
344 				const struct usb_device_id *id)
345 {
346 	struct dsbr100_device *radio;
347 	struct v4l2_device *v4l2_dev;
348 	int retval;
349 
350 	radio = kzalloc(sizeof(struct dsbr100_device), GFP_KERNEL);
351 
352 	if (!radio)
353 		return -ENOMEM;
354 
355 	radio->transfer_buffer = kmalloc(TB_LEN, GFP_KERNEL);
356 
357 	if (!(radio->transfer_buffer)) {
358 		kfree(radio);
359 		return -ENOMEM;
360 	}
361 
362 	v4l2_dev = &radio->v4l2_dev;
363 	v4l2_dev->release = usb_dsbr100_release;
364 
365 	retval = v4l2_device_register(&intf->dev, v4l2_dev);
366 	if (retval < 0) {
367 		v4l2_err(v4l2_dev, "couldn't register v4l2_device\n");
368 		goto err_reg_dev;
369 	}
370 
371 	v4l2_ctrl_handler_init(&radio->hdl, 1);
372 	v4l2_ctrl_new_std(&radio->hdl, &usb_dsbr100_ctrl_ops,
373 			  V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
374 	if (radio->hdl.error) {
375 		retval = radio->hdl.error;
376 		v4l2_err(v4l2_dev, "couldn't register control\n");
377 		goto err_reg_ctrl;
378 	}
379 	mutex_init(&radio->v4l2_lock);
380 	strscpy(radio->videodev.name, v4l2_dev->name,
381 		sizeof(radio->videodev.name));
382 	radio->videodev.v4l2_dev = v4l2_dev;
383 	radio->videodev.fops = &usb_dsbr100_fops;
384 	radio->videodev.ioctl_ops = &usb_dsbr100_ioctl_ops;
385 	radio->videodev.release = video_device_release_empty;
386 	radio->videodev.lock = &radio->v4l2_lock;
387 	radio->videodev.ctrl_handler = &radio->hdl;
388 	radio->videodev.device_caps = V4L2_CAP_RADIO | V4L2_CAP_TUNER;
389 
390 	radio->usbdev = interface_to_usbdev(intf);
391 	radio->curfreq = FREQ_MIN * FREQ_MUL;
392 	radio->muted = true;
393 
394 	video_set_drvdata(&radio->videodev, radio);
395 	usb_set_intfdata(intf, radio);
396 
397 	retval = video_register_device(&radio->videodev, VFL_TYPE_RADIO, radio_nr);
398 	if (retval == 0)
399 		return 0;
400 	v4l2_err(v4l2_dev, "couldn't register video device\n");
401 
402 err_reg_ctrl:
403 	v4l2_ctrl_handler_free(&radio->hdl);
404 	v4l2_device_unregister(v4l2_dev);
405 err_reg_dev:
406 	kfree(radio->transfer_buffer);
407 	kfree(radio);
408 	return retval;
409 }
410 
411 static const struct usb_device_id usb_dsbr100_device_table[] = {
412 	{ USB_DEVICE(DSB100_VENDOR, DSB100_PRODUCT) },
413 	{ }						/* Terminating entry */
414 };
415 
416 MODULE_DEVICE_TABLE(usb, usb_dsbr100_device_table);
417 
418 /* USB subsystem interface */
419 static struct usb_driver usb_dsbr100_driver = {
420 	.name			= "dsbr100",
421 	.probe			= usb_dsbr100_probe,
422 	.disconnect		= usb_dsbr100_disconnect,
423 	.id_table		= usb_dsbr100_device_table,
424 	.suspend		= usb_dsbr100_suspend,
425 	.resume			= usb_dsbr100_resume,
426 	.reset_resume		= usb_dsbr100_resume,
427 };
428 
429 module_usb_driver(usb_dsbr100_driver);
430