1 /*
2  * Driver for the MasterKit MA901 USB FM radio. This device plugs
3  * into the USB port and an analog audio input or headphones, so this thing
4  * only deals with initialization, frequency setting, volume.
5  *
6  * Copyright (c) 2012 Alexey Klimov <klimov.linux@gmail.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21  */
22 
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/init.h>
26 #include <linux/slab.h>
27 #include <linux/input.h>
28 #include <linux/videodev2.h>
29 #include <media/v4l2-device.h>
30 #include <media/v4l2-ioctl.h>
31 #include <media/v4l2-ctrls.h>
32 #include <media/v4l2-event.h>
33 #include <linux/usb.h>
34 #include <linux/mutex.h>
35 
36 #define DRIVER_AUTHOR "Alexey Klimov <klimov.linux@gmail.com>"
37 #define DRIVER_DESC "Masterkit MA901 USB FM radio driver"
38 #define DRIVER_VERSION "0.0.1"
39 
40 MODULE_AUTHOR(DRIVER_AUTHOR);
41 MODULE_DESCRIPTION(DRIVER_DESC);
42 MODULE_LICENSE("GPL");
43 MODULE_VERSION(DRIVER_VERSION);
44 
45 #define USB_MA901_VENDOR  0x16c0
46 #define USB_MA901_PRODUCT 0x05df
47 
48 /* dev_warn macro with driver name */
49 #define MA901_DRIVER_NAME "radio-ma901"
50 #define ma901radio_dev_warn(dev, fmt, arg...)				\
51 		dev_warn(dev, MA901_DRIVER_NAME " - " fmt, ##arg)
52 
53 #define ma901radio_dev_err(dev, fmt, arg...) \
54 		dev_err(dev, MA901_DRIVER_NAME " - " fmt, ##arg)
55 
56 /* Probably USB_TIMEOUT should be modified in module parameter */
57 #define BUFFER_LENGTH 8
58 #define USB_TIMEOUT 500
59 
60 #define FREQ_MIN  87.5
61 #define FREQ_MAX 108.0
62 #define FREQ_MUL 16000
63 
64 #define MA901_VOLUME_MAX 16
65 #define MA901_VOLUME_MIN 0
66 
67 /* Commands that device should understand
68  * List isn't full and will be updated with implementation of new functions
69  */
70 #define MA901_RADIO_SET_FREQ		0x03
71 #define MA901_RADIO_SET_VOLUME		0x04
72 #define MA901_RADIO_SET_MONO_STEREO	0x05
73 
74 /* Comfortable defines for ma901radio_set_stereo */
75 #define MA901_WANT_STEREO		0x50
76 #define MA901_WANT_MONO			0xd0
77 
78 /* module parameter */
79 static int radio_nr = -1;
80 module_param(radio_nr, int, 0);
81 MODULE_PARM_DESC(radio_nr, "Radio file number");
82 
83 /* Data for one (physical) device */
84 struct ma901radio_device {
85 	/* reference to USB and video device */
86 	struct usb_device *usbdev;
87 	struct usb_interface *intf;
88 	struct video_device vdev;
89 	struct v4l2_device v4l2_dev;
90 	struct v4l2_ctrl_handler hdl;
91 
92 	u8 *buffer;
93 	struct mutex lock;	/* buffer locking */
94 	int curfreq;
95 	u16 volume;
96 	int stereo;
97 	bool muted;
98 };
99 
100 static inline struct ma901radio_device *to_ma901radio_dev(struct v4l2_device *v4l2_dev)
101 {
102 	return container_of(v4l2_dev, struct ma901radio_device, v4l2_dev);
103 }
104 
105 /* set a frequency, freq is defined by v4l's TUNER_LOW, i.e. 1/16th kHz */
106 static int ma901radio_set_freq(struct ma901radio_device *radio, int freq)
107 {
108 	unsigned int freq_send = 0x300 + (freq >> 5) / 25;
109 	int retval;
110 
111 	radio->buffer[0] = 0x0a;
112 	radio->buffer[1] = MA901_RADIO_SET_FREQ;
113 	radio->buffer[2] = ((freq_send >> 8) & 0xff) + 0x80;
114 	radio->buffer[3] = freq_send & 0xff;
115 	radio->buffer[4] = 0x00;
116 	radio->buffer[5] = 0x00;
117 	radio->buffer[6] = 0x00;
118 	radio->buffer[7] = 0x00;
119 
120 	retval = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
121 				9, 0x21, 0x0300, 0,
122 				radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
123 	if (retval < 0)
124 		return retval;
125 
126 	radio->curfreq = freq;
127 	return 0;
128 }
129 
130 static int ma901radio_set_volume(struct ma901radio_device *radio, u16 vol_to_set)
131 {
132 	int retval;
133 
134 	radio->buffer[0] = 0x0a;
135 	radio->buffer[1] = MA901_RADIO_SET_VOLUME;
136 	radio->buffer[2] = 0xc2;
137 	radio->buffer[3] = vol_to_set + 0x20;
138 	radio->buffer[4] = 0x00;
139 	radio->buffer[5] = 0x00;
140 	radio->buffer[6] = 0x00;
141 	radio->buffer[7] = 0x00;
142 
143 	retval = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
144 				9, 0x21, 0x0300, 0,
145 				radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
146 	if (retval < 0)
147 		return retval;
148 
149 	radio->volume = vol_to_set;
150 	return retval;
151 }
152 
153 static int ma901_set_stereo(struct ma901radio_device *radio, u8 stereo)
154 {
155 	int retval;
156 
157 	radio->buffer[0] = 0x0a;
158 	radio->buffer[1] = MA901_RADIO_SET_MONO_STEREO;
159 	radio->buffer[2] = stereo;
160 	radio->buffer[3] = 0x00;
161 	radio->buffer[4] = 0x00;
162 	radio->buffer[5] = 0x00;
163 	radio->buffer[6] = 0x00;
164 	radio->buffer[7] = 0x00;
165 
166 	retval = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
167 				9, 0x21, 0x0300, 0,
168 				radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
169 
170 	if (retval < 0)
171 		return retval;
172 
173 	if (stereo == MA901_WANT_STEREO)
174 		radio->stereo = V4L2_TUNER_MODE_STEREO;
175 	else
176 		radio->stereo = V4L2_TUNER_MODE_MONO;
177 
178 	return retval;
179 }
180 
181 /* Handle unplugging the device.
182  * We call video_unregister_device in any case.
183  * The last function called in this procedure is
184  * usb_ma901radio_device_release.
185  */
186 static void usb_ma901radio_disconnect(struct usb_interface *intf)
187 {
188 	struct ma901radio_device *radio = to_ma901radio_dev(usb_get_intfdata(intf));
189 
190 	mutex_lock(&radio->lock);
191 	video_unregister_device(&radio->vdev);
192 	usb_set_intfdata(intf, NULL);
193 	v4l2_device_disconnect(&radio->v4l2_dev);
194 	mutex_unlock(&radio->lock);
195 	v4l2_device_put(&radio->v4l2_dev);
196 }
197 
198 /* vidioc_querycap - query device capabilities */
199 static int vidioc_querycap(struct file *file, void *priv,
200 					struct v4l2_capability *v)
201 {
202 	struct ma901radio_device *radio = video_drvdata(file);
203 
204 	strlcpy(v->driver, "radio-ma901", sizeof(v->driver));
205 	strlcpy(v->card, "Masterkit MA901 USB FM Radio", sizeof(v->card));
206 	usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
207 	v->device_caps = V4L2_CAP_RADIO | V4L2_CAP_TUNER;
208 	v->capabilities = v->device_caps | V4L2_CAP_DEVICE_CAPS;
209 	return 0;
210 }
211 
212 /* vidioc_g_tuner - get tuner attributes */
213 static int vidioc_g_tuner(struct file *file, void *priv,
214 				struct v4l2_tuner *v)
215 {
216 	struct ma901radio_device *radio = video_drvdata(file);
217 
218 	if (v->index > 0)
219 		return -EINVAL;
220 
221 	v->signal = 0;
222 
223 	/* TODO: the same words like in _probe() goes here.
224 	 * When receiving of stats will be implemented then we can call
225 	 * ma901radio_get_stat().
226 	 * retval = ma901radio_get_stat(radio, &is_stereo, &v->signal);
227 	 */
228 
229 	strcpy(v->name, "FM");
230 	v->type = V4L2_TUNER_RADIO;
231 	v->rangelow = FREQ_MIN * FREQ_MUL;
232 	v->rangehigh = FREQ_MAX * FREQ_MUL;
233 	v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO;
234 	/* v->rxsubchans = is_stereo ? V4L2_TUNER_SUB_STEREO : V4L2_TUNER_SUB_MONO; */
235 	v->audmode = radio->stereo ?
236 		V4L2_TUNER_MODE_STEREO : V4L2_TUNER_MODE_MONO;
237 	return 0;
238 }
239 
240 /* vidioc_s_tuner - set tuner attributes */
241 static int vidioc_s_tuner(struct file *file, void *priv,
242 				const struct v4l2_tuner *v)
243 {
244 	struct ma901radio_device *radio = video_drvdata(file);
245 
246 	if (v->index > 0)
247 		return -EINVAL;
248 
249 	/* mono/stereo selector */
250 	switch (v->audmode) {
251 	case V4L2_TUNER_MODE_MONO:
252 		return ma901_set_stereo(radio, MA901_WANT_MONO);
253 	default:
254 		return ma901_set_stereo(radio, MA901_WANT_STEREO);
255 	}
256 }
257 
258 /* vidioc_s_frequency - set tuner radio frequency */
259 static int vidioc_s_frequency(struct file *file, void *priv,
260 				const struct v4l2_frequency *f)
261 {
262 	struct ma901radio_device *radio = video_drvdata(file);
263 
264 	if (f->tuner != 0)
265 		return -EINVAL;
266 
267 	return ma901radio_set_freq(radio, clamp_t(unsigned, f->frequency,
268 				FREQ_MIN * FREQ_MUL, FREQ_MAX * FREQ_MUL));
269 }
270 
271 /* vidioc_g_frequency - get tuner radio frequency */
272 static int vidioc_g_frequency(struct file *file, void *priv,
273 				struct v4l2_frequency *f)
274 {
275 	struct ma901radio_device *radio = video_drvdata(file);
276 
277 	if (f->tuner != 0)
278 		return -EINVAL;
279 	f->frequency = radio->curfreq;
280 
281 	return 0;
282 }
283 
284 static int usb_ma901radio_s_ctrl(struct v4l2_ctrl *ctrl)
285 {
286 	struct ma901radio_device *radio =
287 		container_of(ctrl->handler, struct ma901radio_device, hdl);
288 
289 	switch (ctrl->id) {
290 	case V4L2_CID_AUDIO_VOLUME:     /* set volume */
291 		return ma901radio_set_volume(radio, (u16)ctrl->val);
292 	}
293 
294 	return -EINVAL;
295 }
296 
297 /* TODO: Should we really need to implement suspend and resume functions?
298  * Radio has it's own memory and will continue playing if power is present
299  * on usb port and on resume it will start to play again based on freq, volume
300  * values in device memory.
301  */
302 static int usb_ma901radio_suspend(struct usb_interface *intf, pm_message_t message)
303 {
304 	return 0;
305 }
306 
307 static int usb_ma901radio_resume(struct usb_interface *intf)
308 {
309 	return 0;
310 }
311 
312 static const struct v4l2_ctrl_ops usb_ma901radio_ctrl_ops = {
313 	.s_ctrl = usb_ma901radio_s_ctrl,
314 };
315 
316 /* File system interface */
317 static const struct v4l2_file_operations usb_ma901radio_fops = {
318 	.owner		= THIS_MODULE,
319 	.open		= v4l2_fh_open,
320 	.release	= v4l2_fh_release,
321 	.poll		= v4l2_ctrl_poll,
322 	.unlocked_ioctl	= video_ioctl2,
323 };
324 
325 static const struct v4l2_ioctl_ops usb_ma901radio_ioctl_ops = {
326 	.vidioc_querycap    = vidioc_querycap,
327 	.vidioc_g_tuner     = vidioc_g_tuner,
328 	.vidioc_s_tuner     = vidioc_s_tuner,
329 	.vidioc_g_frequency = vidioc_g_frequency,
330 	.vidioc_s_frequency = vidioc_s_frequency,
331 	.vidioc_log_status  = v4l2_ctrl_log_status,
332 	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
333 	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
334 };
335 
336 static void usb_ma901radio_release(struct v4l2_device *v4l2_dev)
337 {
338 	struct ma901radio_device *radio = to_ma901radio_dev(v4l2_dev);
339 
340 	v4l2_ctrl_handler_free(&radio->hdl);
341 	v4l2_device_unregister(&radio->v4l2_dev);
342 	kfree(radio->buffer);
343 	kfree(radio);
344 }
345 
346 /* check if the device is present and register with v4l and usb if it is */
347 static int usb_ma901radio_probe(struct usb_interface *intf,
348 				const struct usb_device_id *id)
349 {
350 	struct usb_device *dev = interface_to_usbdev(intf);
351 	struct ma901radio_device *radio;
352 	int retval = 0;
353 
354 	/* Masterkit MA901 usb radio has the same USB ID as many others
355 	 * Atmel V-USB devices. Let's make additional checks to be sure
356 	 * that this is our device.
357 	 */
358 
359 	if (dev->product && dev->manufacturer &&
360 		(strncmp(dev->product, "MA901", 5) != 0
361 		|| strncmp(dev->manufacturer, "www.masterkit.ru", 16) != 0))
362 		return -ENODEV;
363 
364 	radio = kzalloc(sizeof(struct ma901radio_device), GFP_KERNEL);
365 	if (!radio) {
366 		dev_err(&intf->dev, "kzalloc for ma901radio_device failed\n");
367 		retval = -ENOMEM;
368 		goto err;
369 	}
370 
371 	radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);
372 	if (!radio->buffer) {
373 		dev_err(&intf->dev, "kmalloc for radio->buffer failed\n");
374 		retval = -ENOMEM;
375 		goto err_nobuf;
376 	}
377 
378 	retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
379 	if (retval < 0) {
380 		dev_err(&intf->dev, "couldn't register v4l2_device\n");
381 		goto err_v4l2;
382 	}
383 
384 	v4l2_ctrl_handler_init(&radio->hdl, 1);
385 
386 	/* TODO:It looks like this radio doesn't have mute/unmute control
387 	 * and windows program just emulate it using volume control.
388 	 * Let's plan to do the same in this driver.
389 	 *
390 	 * v4l2_ctrl_new_std(&radio->hdl, &usb_ma901radio_ctrl_ops,
391 	 *		  V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
392 	 */
393 
394 	v4l2_ctrl_new_std(&radio->hdl, &usb_ma901radio_ctrl_ops,
395 			  V4L2_CID_AUDIO_VOLUME, MA901_VOLUME_MIN,
396 			  MA901_VOLUME_MAX, 1, MA901_VOLUME_MAX);
397 
398 	if (radio->hdl.error) {
399 		retval = radio->hdl.error;
400 		dev_err(&intf->dev, "couldn't register control\n");
401 		goto err_ctrl;
402 	}
403 	mutex_init(&radio->lock);
404 
405 	radio->v4l2_dev.ctrl_handler = &radio->hdl;
406 	radio->v4l2_dev.release = usb_ma901radio_release;
407 	strlcpy(radio->vdev.name, radio->v4l2_dev.name,
408 		sizeof(radio->vdev.name));
409 	radio->vdev.v4l2_dev = &radio->v4l2_dev;
410 	radio->vdev.fops = &usb_ma901radio_fops;
411 	radio->vdev.ioctl_ops = &usb_ma901radio_ioctl_ops;
412 	radio->vdev.release = video_device_release_empty;
413 	radio->vdev.lock = &radio->lock;
414 	set_bit(V4L2_FL_USE_FH_PRIO, &radio->vdev.flags);
415 
416 	radio->usbdev = interface_to_usbdev(intf);
417 	radio->intf = intf;
418 	usb_set_intfdata(intf, &radio->v4l2_dev);
419 	radio->curfreq = 95.21 * FREQ_MUL;
420 
421 	video_set_drvdata(&radio->vdev, radio);
422 
423 	/* TODO: we can get some statistics (freq, volume) from device
424 	 * but it's not implemented yet. After insertion in usb-port radio
425 	 * setups frequency and starts playing without any initialization.
426 	 * So we don't call usb_ma901radio_init/get_stat() here.
427 	 * retval = usb_ma901radio_init(radio);
428 	 */
429 
430 	retval = video_register_device(&radio->vdev, VFL_TYPE_RADIO,
431 					radio_nr);
432 	if (retval < 0) {
433 		dev_err(&intf->dev, "could not register video device\n");
434 		goto err_vdev;
435 	}
436 
437 	return 0;
438 
439 err_vdev:
440 	v4l2_ctrl_handler_free(&radio->hdl);
441 err_ctrl:
442 	v4l2_device_unregister(&radio->v4l2_dev);
443 err_v4l2:
444 	kfree(radio->buffer);
445 err_nobuf:
446 	kfree(radio);
447 err:
448 	return retval;
449 }
450 
451 /* USB Device ID List */
452 static struct usb_device_id usb_ma901radio_device_table[] = {
453 	{ USB_DEVICE_AND_INTERFACE_INFO(USB_MA901_VENDOR, USB_MA901_PRODUCT,
454 							USB_CLASS_HID, 0, 0) },
455 	{ }						/* Terminating entry */
456 };
457 
458 MODULE_DEVICE_TABLE(usb, usb_ma901radio_device_table);
459 
460 /* USB subsystem interface */
461 static struct usb_driver usb_ma901radio_driver = {
462 	.name			= MA901_DRIVER_NAME,
463 	.probe			= usb_ma901radio_probe,
464 	.disconnect		= usb_ma901radio_disconnect,
465 	.suspend		= usb_ma901radio_suspend,
466 	.resume			= usb_ma901radio_resume,
467 	.reset_resume		= usb_ma901radio_resume,
468 	.id_table		= usb_ma901radio_device_table,
469 };
470 
471 module_usb_driver(usb_ma901radio_driver);
472