summaryrefslogtreecommitdiffstats
path: root/drivers/media/radio/radio-keene.c
blob: fa3964022b96d939a3c222b90d81bd5bb2822255 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
/*
 * Copyright (c) 2012 Hans Verkuil <hverkuil@xs4all.nl>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

/* kernel includes */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/videodev2.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-event.h>
#include <linux/usb.h>
#include <linux/mutex.h>

/* driver and module definitions */
MODULE_AUTHOR("Hans Verkuil <hverkuil@xs4all.nl>");
MODULE_DESCRIPTION("Keene FM Transmitter driver");
MODULE_LICENSE("GPL");

/* Actually, it advertises itself as a Logitech */
#define USB_KEENE_VENDOR 0x046d
#define USB_KEENE_PRODUCT 0x0a0e

/* Probably USB_TIMEOUT should be modified in module parameter */
#define BUFFER_LENGTH 8
#define USB_TIMEOUT 500

/* Frequency limits in MHz */
#define FREQ_MIN  76U
#define FREQ_MAX 108U
#define FREQ_MUL 16000U

/* USB Device ID List */
static struct usb_device_id usb_keene_device_table[] = {
	{USB_DEVICE_AND_INTERFACE_INFO(USB_KEENE_VENDOR, USB_KEENE_PRODUCT,
							USB_CLASS_HID, 0, 0) },
	{ }						/* Terminating entry */
};

MODULE_DEVICE_TABLE(usb, usb_keene_device_table);

struct keene_device {
	struct usb_device *usbdev;
	struct usb_interface *intf;
	struct video_device vdev;
	struct v4l2_device v4l2_dev;
	struct v4l2_ctrl_handler hdl;
	struct mutex lock;

	u8 *buffer;
	unsigned curfreq;
	u8 tx;
	u8 pa;
	bool stereo;
	bool muted;
	bool preemph_75_us;
};

static inline struct keene_device *to_keene_dev(struct v4l2_device *v4l2_dev)
{
	return container_of(v4l2_dev, struct keene_device, v4l2_dev);
}

/* Set frequency (if non-0), PA, mute and turn on/off the FM transmitter. */
static int keene_cmd_main(struct keene_device *radio, unsigned freq, bool play)
{
	unsigned short freq_send = freq ? (freq - 76 * 16000) / 800 : 0;
	int ret;

	radio->buffer[0] = 0x00;
	radio->buffer[1] = 0x50;
	radio->buffer[2] = (freq_send >> 8) & 0xff;
	radio->buffer[3] = freq_send & 0xff;
	radio->buffer[4] = radio->pa;
	/* If bit 4 is set, then tune to the frequency.
	   If bit 3 is set, then unmute; if bit 2 is set, then mute.
	   If bit 1 is set, then enter idle mode; if bit 0 is set,
	   then enter transmit mode.
	 */
	radio->buffer[5] = (radio->muted ? 4 : 8) | (play ? 1 : 2) |
							(freq ? 0x10 : 0);
	radio->buffer[6] = 0x00;
	radio->buffer[7] = 0x00;

	ret = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
		9, 0x21, 0x200, 2, radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);

	if (ret < 0) {
		dev_warn(&radio->vdev.dev, "%s failed (%d)\n", __func__, ret);
		return ret;
	}
	if (freq)
		radio->curfreq = freq;
	return 0;
}

/* Set TX, stereo and preemphasis mode (50 us vs 75 us). */
static int keene_cmd_set(struct keene_device *radio)
{
	int ret;

	radio->buffer[0] = 0x00;
	radio->buffer[1] = 0x51;
	radio->buffer[2] = radio->tx;
	/* If bit 0 is set, then transmit mono, otherwise stereo.
	   If bit 2 is set, then enable 75 us preemphasis, otherwise
	   it is 50 us. */
	radio->buffer[3] = (radio->stereo ? 0 : 1) | (radio->preemph_75_us ? 4 : 0);
	radio->buffer[4] = 0x00;
	radio->buffer[5] = 0x00;
	radio->buffer[6] = 0x00;
	radio->buffer[7] = 0x00;

	ret = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
		9, 0x21, 0x200, 2, radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);

	if (ret < 0) {
		dev_warn(&radio->vdev.dev, "%s failed (%d)\n", __func__, ret);
		return ret;
	}
	return 0;
}

/* Handle unplugging the device.
 * We call video_unregister_device in any case.
 * The last function called in this procedure is
 * usb_keene_device_release.
 */
static void usb_keene_disconnect(struct usb_interface *intf)
{
	struct keene_device *radio = to_keene_dev(usb_get_intfdata(intf));

	mutex_lock(&radio->lock);
	usb_set_intfdata(intf, NULL);
	video_unregister_device(&radio->vdev);
	v4l2_device_disconnect(&radio->v4l2_dev);
	mutex_unlock(&radio->lock);
	v4l2_device_put(&radio->v4l2_dev);
}

static int usb_keene_suspend(struct usb_interface *intf, pm_message_t message)
{
	struct keene_device *radio = to_keene_dev(usb_get_intfdata(intf));

	return keene_cmd_main(radio, 0, false);
}

static int usb_keene_resume(struct usb_interface *intf)
{
	struct keene_device *radio = to_keene_dev(usb_get_intfdata(intf));

	mdelay(50);
	keene_cmd_set(radio);
	keene_cmd_main(radio, radio->curfreq, true);
	return 0;
}

static int vidioc_querycap(struct file *file, void *priv,
					struct v4l2_capability *v)
{
	struct keene_device *radio = video_drvdata(file);

	strlcpy(v->driver, "radio-keene", sizeof(v->driver));
	strlcpy(v->card, "Keene FM Transmitter", sizeof(v->card));
	usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
	v->device_caps = V4L2_CAP_RADIO | V4L2_CAP_MODULATOR;
	v->capabilities = v->device_caps | V4L2_CAP_DEVICE_CAPS;
	return 0;
}

static int vidioc_g_modulator(struct file *file, void *priv,
				struct v4l2_modulator *v)
{
	struct keene_device *radio = video_drvdata(file);

	if (v->index > 0)
		return -EINVAL;

	strlcpy(v->name, "FM", sizeof(v->name));
	v->rangelow = FREQ_MIN * FREQ_MUL;
	v->rangehigh = FREQ_MAX * FREQ_MUL;
	v->txsubchans = radio->stereo ? V4L2_TUNER_SUB_STEREO : V4L2_TUNER_SUB_MONO;
	v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO;
	return 0;
}

static int vidioc_s_modulator(struct file *file, void *priv,
				const struct v4l2_modulator *v)
{
	struct keene_device *radio = video_drvdata(file);

	if (v->index > 0)
		return -EINVAL;

	radio->stereo = (v->txsubchans == V4L2_TUNER_SUB_STEREO);
	return keene_cmd_set(radio);
}

static int vidioc_s_frequency(struct file *file, void *priv,
				const struct v4l2_frequency *f)
{
	struct keene_device *radio = video_drvdata(file);
	unsigned freq = f->frequency;

	if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
		return -EINVAL;
	freq = clamp(freq, FREQ_MIN * FREQ_MUL, FREQ_MAX * FREQ_MUL);
	return keene_cmd_main(radio, freq, true);
}

static int vidioc_g_frequency(struct file *file, void *priv,
				struct v4l2_frequency *f)
{
	struct keene_device *radio = video_drvdata(file);

	if (f->tuner != 0)
		return -EINVAL;
	f->type = V4L2_TUNER_RADIO;
	f->frequency = radio->curfreq;
	return 0;
}

static int keene_s_ctrl(struct v4l2_ctrl *ctrl)
{
	static const u8 db2tx[] = {
	     /*	 -15,  -12,   -9,   -6,   -3,    0 dB */
		0x03, 0x13, 0x02, 0x12, 0x22, 0x32,
	     /*	   3,    6,    9,   12,   15,   18 dB */
		0x21, 0x31, 0x20, 0x30, 0x40, 0x50
	};
	struct keene_device *radio =
		container_of(ctrl->handler, struct keene_device, hdl);

	switch (ctrl->id) {
	case V4L2_CID_AUDIO_MUTE:
		radio->muted = ctrl->val;
		return keene_cmd_main(radio, 0, true);

	case V4L2_CID_TUNE_POWER_LEVEL:
		/* To go from dBuV to the register value we apply the
		   following formula: */
		radio->pa = (ctrl->val - 71) * 100 / 62;
		return keene_cmd_main(radio, 0, true);

	case V4L2_CID_TUNE_PREEMPHASIS:
		radio->preemph_75_us = ctrl->val == V4L2_PREEMPHASIS_75_uS;
		return keene_cmd_set(radio);

	case V4L2_CID_AUDIO_COMPRESSION_GAIN:
		radio->tx = db2tx[(ctrl->val - ctrl->minimum) / ctrl->step];
		return keene_cmd_set(radio);
	}
	return -EINVAL;
}

/* File system interface */
static const struct v4l2_file_operations usb_keene_fops = {
	.owner		= THIS_MODULE,
	.open           = v4l2_fh_open,
	.release        = v4l2_fh_release,
	.poll		= v4l2_ctrl_poll,
	.unlocked_ioctl	= video_ioctl2,
};

static const struct v4l2_ctrl_ops keene_ctrl_ops = {
	.s_ctrl = keene_s_ctrl,
};

static const struct v4l2_ioctl_ops usb_keene_ioctl_ops = {
	.vidioc_querycap    = vidioc_querycap,
	.vidioc_g_modulator = vidioc_g_modulator,
	.vidioc_s_modulator = vidioc_s_modulator,
	.vidioc_g_frequency = vidioc_g_frequency,
	.vidioc_s_frequency = vidioc_s_frequency,
	.vidioc_log_status = v4l2_ctrl_log_status,
	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
};

static void usb_keene_video_device_release(struct v4l2_device *v4l2_dev)
{
	struct keene_device *radio = to_keene_dev(v4l2_dev);

	/* free rest memory */
	v4l2_ctrl_handler_free(&radio->hdl);
	kfree(radio->buffer);
	kfree(radio);
}

/* check if the device is present and register with v4l and usb if it is */
static int usb_keene_probe(struct usb_interface *intf,
				const struct usb_device_id *id)
{
	struct usb_device *dev = interface_to_usbdev(intf);
	struct keene_device *radio;
	struct v4l2_ctrl_handler *hdl;
	int retval = 0;

	/*
	 * The Keene FM transmitter USB device has the same USB ID as
	 * the Logitech AudioHub Speaker, but it should ignore the hid.
	 * Check if the name is that of the Keene device.
	 * If not, then someone connected the AudioHub and we shouldn't
	 * attempt to handle this driver.
	 * For reference: the product name of the AudioHub is
	 * "AudioHub Speaker".
	 */
	if (dev->product && strcmp(dev->product, "B-LINK USB Audio  "))
		return -ENODEV;

	radio = kzalloc(sizeof(struct keene_device), GFP_KERNEL);
	if (radio)
		radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);

	if (!radio || !radio->buffer) {
		dev_err(&intf->dev, "kmalloc for keene_device failed\n");
		kfree(radio);
		retval = -ENOMEM;
		goto err;
	}

	hdl = &radio->hdl;
	v4l2_ctrl_handler_init(hdl, 4);
	v4l2_ctrl_new_std(hdl, &keene_ctrl_ops, V4L2_CID_AUDIO_MUTE,
			0, 1, 1, 0);
	v4l2_ctrl_new_std_menu(hdl, &keene_ctrl_ops, V4L2_CID_TUNE_PREEMPHASIS,
			V4L2_PREEMPHASIS_75_uS, 1, V4L2_PREEMPHASIS_50_uS);
	v4l2_ctrl_new_std(hdl, &keene_ctrl_ops, V4L2_CID_TUNE_POWER_LEVEL,
			84, 118, 1, 118);
	v4l2_ctrl_new_std(hdl, &keene_ctrl_ops, V4L2_CID_AUDIO_COMPRESSION_GAIN,
			-15, 18, 3, 0);
	radio->pa = 118;
	radio->tx = 0x32;
	radio->stereo = true;
	if (hdl->error) {
		retval = hdl->error;

		v4l2_ctrl_handler_free(hdl);
		goto err_v4l2;
	}
	retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
	if (retval < 0) {
		dev_err(&intf->dev, "couldn't register v4l2_device\n");
		goto err_v4l2;
	}

	mutex_init(&radio->lock);

	radio->v4l2_dev.ctrl_handler = hdl;
	radio->v4l2_dev.release = usb_keene_video_device_release;
	strlcpy(radio->vdev.name, radio->v4l2_dev.name,
		sizeof(radio->vdev.name));
	radio->vdev.v4l2_dev = &radio->v4l2_dev;
	radio->vdev.fops = &usb_keene_fops;
	radio->vdev.ioctl_ops = &usb_keene_ioctl_ops;
	radio->vdev.lock = &radio->lock;
	radio->vdev.release = video_device_release_empty;
	radio->vdev.vfl_dir = VFL_DIR_TX;

	radio->usbdev = interface_to_usbdev(intf);
	radio->intf = intf;
	usb_set_intfdata(intf, &radio->v4l2_dev);

	video_set_drvdata(&radio->vdev, radio);
	set_bit(V4L2_FL_USE_FH_PRIO, &radio->vdev.flags);

	/* at least 11ms is needed in order to settle hardware */
	msleep(20);
	keene_cmd_main(radio, 95.16 * FREQ_MUL, false);

	retval = video_register_device(&radio->vdev, VFL_TYPE_RADIO, -1);
	if (retval < 0) {
		dev_err(&intf->dev, "could not register video device\n");
		goto err_vdev;
	}
	v4l2_ctrl_handler_setup(hdl);
	dev_info(&intf->dev, "V4L2 device registered as %s\n",
			video_device_node_name(&radio->vdev));
	return 0;

err_vdev:
	v4l2_device_unregister(&radio->v4l2_dev);
err_v4l2:
	kfree(radio->buffer);
	kfree(radio);
err:
	return retval;
}

/* USB subsystem interface */
static struct usb_driver usb_keene_driver = {
	.name			= "radio-keene",
	.probe			= usb_keene_probe,
	.disconnect		= usb_keene_disconnect,
	.id_table		= usb_keene_device_table,
	.suspend		= usb_keene_suspend,
	.resume			= usb_keene_resume,
	.reset_resume		= usb_keene_resume,
};

static int __init keene_init(void)
{
	int retval = usb_register(&usb_keene_driver);

	if (retval)
		pr_err(KBUILD_MODNAME
			": usb_register failed. Error number %d\n", retval);

	return retval;
}

static void __exit keene_exit(void)
{
	usb_deregister(&usb_keene_driver);
}

module_init(keene_init);
module_exit(keene_exit);