xref: /openbmc/linux/drivers/media/radio/dsbr100.c (revision be709d48)
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 	v->device_caps = V4L2_CAP_RADIO | V4L2_CAP_TUNER;
181 	v->capabilities = v->device_caps | V4L2_CAP_DEVICE_CAPS;
182 	return 0;
183 }
184 
185 static int vidioc_g_tuner(struct file *file, void *priv,
186 				struct v4l2_tuner *v)
187 {
188 	struct dsbr100_device *radio = video_drvdata(file);
189 
190 	if (v->index > 0)
191 		return -EINVAL;
192 
193 	dsbr100_getstat(radio);
194 	strscpy(v->name, "FM", sizeof(v->name));
195 	v->type = V4L2_TUNER_RADIO;
196 	v->rangelow = FREQ_MIN * FREQ_MUL;
197 	v->rangehigh = FREQ_MAX * FREQ_MUL;
198 	v->rxsubchans = radio->stereo ? V4L2_TUNER_SUB_STEREO :
199 		V4L2_TUNER_SUB_MONO;
200 	v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO;
201 	v->audmode = V4L2_TUNER_MODE_STEREO;
202 	v->signal = radio->stereo ? 0xffff : 0;     /* We can't get the signal strength */
203 	return 0;
204 }
205 
206 static int vidioc_s_tuner(struct file *file, void *priv,
207 				const struct v4l2_tuner *v)
208 {
209 	return v->index ? -EINVAL : 0;
210 }
211 
212 static int vidioc_s_frequency(struct file *file, void *priv,
213 				const struct v4l2_frequency *f)
214 {
215 	struct dsbr100_device *radio = video_drvdata(file);
216 
217 	if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
218 		return -EINVAL;
219 
220 	return dsbr100_setfreq(radio, clamp_t(unsigned, f->frequency,
221 			FREQ_MIN * FREQ_MUL, FREQ_MAX * FREQ_MUL));
222 }
223 
224 static int vidioc_g_frequency(struct file *file, void *priv,
225 				struct v4l2_frequency *f)
226 {
227 	struct dsbr100_device *radio = video_drvdata(file);
228 
229 	if (f->tuner)
230 		return -EINVAL;
231 	f->type = V4L2_TUNER_RADIO;
232 	f->frequency = radio->curfreq;
233 	return 0;
234 }
235 
236 static int usb_dsbr100_s_ctrl(struct v4l2_ctrl *ctrl)
237 {
238 	struct dsbr100_device *radio =
239 		container_of(ctrl->handler, struct dsbr100_device, hdl);
240 
241 	switch (ctrl->id) {
242 	case V4L2_CID_AUDIO_MUTE:
243 		radio->muted = ctrl->val;
244 		return radio->muted ? dsbr100_stop(radio) : dsbr100_start(radio);
245 	}
246 	return -EINVAL;
247 }
248 
249 
250 /* USB subsystem interface begins here */
251 
252 /*
253  * Handle unplugging of the device.
254  * We call video_unregister_device in any case.
255  * The last function called in this procedure is
256  * usb_dsbr100_video_device_release
257  */
258 static void usb_dsbr100_disconnect(struct usb_interface *intf)
259 {
260 	struct dsbr100_device *radio = usb_get_intfdata(intf);
261 
262 	mutex_lock(&radio->v4l2_lock);
263 	/*
264 	 * Disconnect is also called on unload, and in that case we need to
265 	 * mute the device. This call will silently fail if it is called
266 	 * after a physical disconnect.
267 	 */
268 	usb_control_msg(radio->usbdev,
269 		usb_rcvctrlpipe(radio->usbdev, 0),
270 		DSB100_ONOFF,
271 		USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
272 		0x00, 0x00, radio->transfer_buffer, 8, 300);
273 	usb_set_intfdata(intf, NULL);
274 	video_unregister_device(&radio->videodev);
275 	v4l2_device_disconnect(&radio->v4l2_dev);
276 	mutex_unlock(&radio->v4l2_lock);
277 	v4l2_device_put(&radio->v4l2_dev);
278 }
279 
280 
281 /* Suspend device - stop device. */
282 static int usb_dsbr100_suspend(struct usb_interface *intf, pm_message_t message)
283 {
284 	struct dsbr100_device *radio = usb_get_intfdata(intf);
285 
286 	mutex_lock(&radio->v4l2_lock);
287 	if (!radio->muted && dsbr100_stop(radio) < 0)
288 		dev_warn(&intf->dev, "dsbr100_stop failed\n");
289 	mutex_unlock(&radio->v4l2_lock);
290 
291 	dev_info(&intf->dev, "going into suspend..\n");
292 	return 0;
293 }
294 
295 /* Resume device - start device. */
296 static int usb_dsbr100_resume(struct usb_interface *intf)
297 {
298 	struct dsbr100_device *radio = usb_get_intfdata(intf);
299 
300 	mutex_lock(&radio->v4l2_lock);
301 	if (!radio->muted && dsbr100_start(radio) < 0)
302 		dev_warn(&intf->dev, "dsbr100_start failed\n");
303 	mutex_unlock(&radio->v4l2_lock);
304 
305 	dev_info(&intf->dev, "coming out of suspend..\n");
306 	return 0;
307 }
308 
309 /* free data structures */
310 static void usb_dsbr100_release(struct v4l2_device *v4l2_dev)
311 {
312 	struct dsbr100_device *radio = v4l2_dev_to_radio(v4l2_dev);
313 
314 	v4l2_ctrl_handler_free(&radio->hdl);
315 	v4l2_device_unregister(&radio->v4l2_dev);
316 	kfree(radio->transfer_buffer);
317 	kfree(radio);
318 }
319 
320 static const struct v4l2_ctrl_ops usb_dsbr100_ctrl_ops = {
321 	.s_ctrl = usb_dsbr100_s_ctrl,
322 };
323 
324 /* File system interface */
325 static const struct v4l2_file_operations usb_dsbr100_fops = {
326 	.owner		= THIS_MODULE,
327 	.unlocked_ioctl	= video_ioctl2,
328 	.open           = v4l2_fh_open,
329 	.release        = v4l2_fh_release,
330 	.poll		= v4l2_ctrl_poll,
331 };
332 
333 static const struct v4l2_ioctl_ops usb_dsbr100_ioctl_ops = {
334 	.vidioc_querycap    = vidioc_querycap,
335 	.vidioc_g_tuner     = vidioc_g_tuner,
336 	.vidioc_s_tuner     = vidioc_s_tuner,
337 	.vidioc_g_frequency = vidioc_g_frequency,
338 	.vidioc_s_frequency = vidioc_s_frequency,
339 	.vidioc_log_status  = v4l2_ctrl_log_status,
340 	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
341 	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
342 };
343 
344 /* check if the device is present and register with v4l and usb if it is */
345 static int usb_dsbr100_probe(struct usb_interface *intf,
346 				const struct usb_device_id *id)
347 {
348 	struct dsbr100_device *radio;
349 	struct v4l2_device *v4l2_dev;
350 	int retval;
351 
352 	radio = kzalloc(sizeof(struct dsbr100_device), GFP_KERNEL);
353 
354 	if (!radio)
355 		return -ENOMEM;
356 
357 	radio->transfer_buffer = kmalloc(TB_LEN, GFP_KERNEL);
358 
359 	if (!(radio->transfer_buffer)) {
360 		kfree(radio);
361 		return -ENOMEM;
362 	}
363 
364 	v4l2_dev = &radio->v4l2_dev;
365 	v4l2_dev->release = usb_dsbr100_release;
366 
367 	retval = v4l2_device_register(&intf->dev, v4l2_dev);
368 	if (retval < 0) {
369 		v4l2_err(v4l2_dev, "couldn't register v4l2_device\n");
370 		goto err_reg_dev;
371 	}
372 
373 	v4l2_ctrl_handler_init(&radio->hdl, 1);
374 	v4l2_ctrl_new_std(&radio->hdl, &usb_dsbr100_ctrl_ops,
375 			  V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
376 	if (radio->hdl.error) {
377 		retval = radio->hdl.error;
378 		v4l2_err(v4l2_dev, "couldn't register control\n");
379 		goto err_reg_ctrl;
380 	}
381 	mutex_init(&radio->v4l2_lock);
382 	strscpy(radio->videodev.name, v4l2_dev->name,
383 		sizeof(radio->videodev.name));
384 	radio->videodev.v4l2_dev = v4l2_dev;
385 	radio->videodev.fops = &usb_dsbr100_fops;
386 	radio->videodev.ioctl_ops = &usb_dsbr100_ioctl_ops;
387 	radio->videodev.release = video_device_release_empty;
388 	radio->videodev.lock = &radio->v4l2_lock;
389 	radio->videodev.ctrl_handler = &radio->hdl;
390 
391 	radio->usbdev = interface_to_usbdev(intf);
392 	radio->curfreq = FREQ_MIN * FREQ_MUL;
393 	radio->muted = true;
394 
395 	video_set_drvdata(&radio->videodev, radio);
396 	usb_set_intfdata(intf, radio);
397 
398 	retval = video_register_device(&radio->videodev, VFL_TYPE_RADIO, radio_nr);
399 	if (retval == 0)
400 		return 0;
401 	v4l2_err(v4l2_dev, "couldn't register video device\n");
402 
403 err_reg_ctrl:
404 	v4l2_ctrl_handler_free(&radio->hdl);
405 	v4l2_device_unregister(v4l2_dev);
406 err_reg_dev:
407 	kfree(radio->transfer_buffer);
408 	kfree(radio);
409 	return retval;
410 }
411 
412 static const struct usb_device_id usb_dsbr100_device_table[] = {
413 	{ USB_DEVICE(DSB100_VENDOR, DSB100_PRODUCT) },
414 	{ }						/* Terminating entry */
415 };
416 
417 MODULE_DEVICE_TABLE(usb, usb_dsbr100_device_table);
418 
419 /* USB subsystem interface */
420 static struct usb_driver usb_dsbr100_driver = {
421 	.name			= "dsbr100",
422 	.probe			= usb_dsbr100_probe,
423 	.disconnect		= usb_dsbr100_disconnect,
424 	.id_table		= usb_dsbr100_device_table,
425 	.suspend		= usb_dsbr100_suspend,
426 	.resume			= usb_dsbr100_resume,
427 	.reset_resume		= usb_dsbr100_resume,
428 };
429 
430 module_usb_driver(usb_dsbr100_driver);
431