1/*
2 * Copyright (c) 2012 Hans Verkuil <hverkuil@xs4all.nl>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 */
18
19/* kernel includes */
20#include <linux/kernel.h>
21#include <linux/module.h>
22#include <linux/init.h>
23#include <linux/slab.h>
24#include <linux/input.h>
25#include <linux/videodev2.h>
26#include <media/v4l2-device.h>
27#include <media/v4l2-ioctl.h>
28#include <media/v4l2-ctrls.h>
29#include <media/v4l2-event.h>
30#include <linux/usb.h>
31#include <linux/mutex.h>
32
33/* driver and module definitions */
34MODULE_AUTHOR("Hans Verkuil <hverkuil@xs4all.nl>");
35MODULE_DESCRIPTION("Keene FM Transmitter driver");
36MODULE_LICENSE("GPL");
37
38/* Actually, it advertises itself as a Logitech */
39#define USB_KEENE_VENDOR 0x046d
40#define USB_KEENE_PRODUCT 0x0a0e
41
42/* Probably USB_TIMEOUT should be modified in module parameter */
43#define BUFFER_LENGTH 8
44#define USB_TIMEOUT 500
45
46/* Frequency limits in MHz */
47#define FREQ_MIN  76U
48#define FREQ_MAX 108U
49#define FREQ_MUL 16000U
50
51/* USB Device ID List */
52static struct usb_device_id usb_keene_device_table[] = {
53	{USB_DEVICE_AND_INTERFACE_INFO(USB_KEENE_VENDOR, USB_KEENE_PRODUCT,
54							USB_CLASS_HID, 0, 0) },
55	{ }						/* Terminating entry */
56};
57
58MODULE_DEVICE_TABLE(usb, usb_keene_device_table);
59
60struct keene_device {
61	struct usb_device *usbdev;
62	struct usb_interface *intf;
63	struct video_device vdev;
64	struct v4l2_device v4l2_dev;
65	struct v4l2_ctrl_handler hdl;
66	struct mutex lock;
67
68	u8 *buffer;
69	unsigned curfreq;
70	u8 tx;
71	u8 pa;
72	bool stereo;
73	bool muted;
74	bool preemph_75_us;
75};
76
77static inline struct keene_device *to_keene_dev(struct v4l2_device *v4l2_dev)
78{
79	return container_of(v4l2_dev, struct keene_device, v4l2_dev);
80}
81
82/* Set frequency (if non-0), PA, mute and turn on/off the FM transmitter. */
83static int keene_cmd_main(struct keene_device *radio, unsigned freq, bool play)
84{
85	unsigned short freq_send = freq ? (freq - 76 * 16000) / 800 : 0;
86	int ret;
87
88	radio->buffer[0] = 0x00;
89	radio->buffer[1] = 0x50;
90	radio->buffer[2] = (freq_send >> 8) & 0xff;
91	radio->buffer[3] = freq_send & 0xff;
92	radio->buffer[4] = radio->pa;
93	/* If bit 4 is set, then tune to the frequency.
94	   If bit 3 is set, then unmute; if bit 2 is set, then mute.
95	   If bit 1 is set, then enter idle mode; if bit 0 is set,
96	   then enter transmit mode.
97	 */
98	radio->buffer[5] = (radio->muted ? 4 : 8) | (play ? 1 : 2) |
99							(freq ? 0x10 : 0);
100	radio->buffer[6] = 0x00;
101	radio->buffer[7] = 0x00;
102
103	ret = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
104		9, 0x21, 0x200, 2, radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
105
106	if (ret < 0) {
107		dev_warn(&radio->vdev.dev, "%s failed (%d)\n", __func__, ret);
108		return ret;
109	}
110	if (freq)
111		radio->curfreq = freq;
112	return 0;
113}
114
115/* Set TX, stereo and preemphasis mode (50 us vs 75 us). */
116static int keene_cmd_set(struct keene_device *radio)
117{
118	int ret;
119
120	radio->buffer[0] = 0x00;
121	radio->buffer[1] = 0x51;
122	radio->buffer[2] = radio->tx;
123	/* If bit 0 is set, then transmit mono, otherwise stereo.
124	   If bit 2 is set, then enable 75 us preemphasis, otherwise
125	   it is 50 us. */
126	radio->buffer[3] = (radio->stereo ? 0 : 1) | (radio->preemph_75_us ? 4 : 0);
127	radio->buffer[4] = 0x00;
128	radio->buffer[5] = 0x00;
129	radio->buffer[6] = 0x00;
130	radio->buffer[7] = 0x00;
131
132	ret = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
133		9, 0x21, 0x200, 2, radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
134
135	if (ret < 0) {
136		dev_warn(&radio->vdev.dev, "%s failed (%d)\n", __func__, ret);
137		return ret;
138	}
139	return 0;
140}
141
142/* Handle unplugging the device.
143 * We call video_unregister_device in any case.
144 * The last function called in this procedure is
145 * usb_keene_device_release.
146 */
147static void usb_keene_disconnect(struct usb_interface *intf)
148{
149	struct keene_device *radio = to_keene_dev(usb_get_intfdata(intf));
150
151	mutex_lock(&radio->lock);
152	usb_set_intfdata(intf, NULL);
153	video_unregister_device(&radio->vdev);
154	v4l2_device_disconnect(&radio->v4l2_dev);
155	mutex_unlock(&radio->lock);
156	v4l2_device_put(&radio->v4l2_dev);
157}
158
159static int usb_keene_suspend(struct usb_interface *intf, pm_message_t message)
160{
161	struct keene_device *radio = to_keene_dev(usb_get_intfdata(intf));
162
163	return keene_cmd_main(radio, 0, false);
164}
165
166static int usb_keene_resume(struct usb_interface *intf)
167{
168	struct keene_device *radio = to_keene_dev(usb_get_intfdata(intf));
169
170	mdelay(50);
171	keene_cmd_set(radio);
172	keene_cmd_main(radio, radio->curfreq, true);
173	return 0;
174}
175
176static int vidioc_querycap(struct file *file, void *priv,
177					struct v4l2_capability *v)
178{
179	struct keene_device *radio = video_drvdata(file);
180
181	strlcpy(v->driver, "radio-keene", sizeof(v->driver));
182	strlcpy(v->card, "Keene FM Transmitter", 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_MODULATOR;
185	v->capabilities = v->device_caps | V4L2_CAP_DEVICE_CAPS;
186	return 0;
187}
188
189static int vidioc_g_modulator(struct file *file, void *priv,
190				struct v4l2_modulator *v)
191{
192	struct keene_device *radio = video_drvdata(file);
193
194	if (v->index > 0)
195		return -EINVAL;
196
197	strlcpy(v->name, "FM", sizeof(v->name));
198	v->rangelow = FREQ_MIN * FREQ_MUL;
199	v->rangehigh = FREQ_MAX * FREQ_MUL;
200	v->txsubchans = radio->stereo ? V4L2_TUNER_SUB_STEREO : V4L2_TUNER_SUB_MONO;
201	v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO;
202	return 0;
203}
204
205static int vidioc_s_modulator(struct file *file, void *priv,
206				const struct v4l2_modulator *v)
207{
208	struct keene_device *radio = video_drvdata(file);
209
210	if (v->index > 0)
211		return -EINVAL;
212
213	radio->stereo = (v->txsubchans == V4L2_TUNER_SUB_STEREO);
214	return keene_cmd_set(radio);
215}
216
217static int vidioc_s_frequency(struct file *file, void *priv,
218				const struct v4l2_frequency *f)
219{
220	struct keene_device *radio = video_drvdata(file);
221	unsigned freq = f->frequency;
222
223	if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
224		return -EINVAL;
225	freq = clamp(freq, FREQ_MIN * FREQ_MUL, FREQ_MAX * FREQ_MUL);
226	return keene_cmd_main(radio, freq, true);
227}
228
229static int vidioc_g_frequency(struct file *file, void *priv,
230				struct v4l2_frequency *f)
231{
232	struct keene_device *radio = video_drvdata(file);
233
234	if (f->tuner != 0)
235		return -EINVAL;
236	f->type = V4L2_TUNER_RADIO;
237	f->frequency = radio->curfreq;
238	return 0;
239}
240
241static int keene_s_ctrl(struct v4l2_ctrl *ctrl)
242{
243	static const u8 db2tx[] = {
244	     /*	 -15,  -12,   -9,   -6,   -3,    0 dB */
245		0x03, 0x13, 0x02, 0x12, 0x22, 0x32,
246	     /*	   3,    6,    9,   12,   15,   18 dB */
247		0x21, 0x31, 0x20, 0x30, 0x40, 0x50
248	};
249	struct keene_device *radio =
250		container_of(ctrl->handler, struct keene_device, hdl);
251
252	switch (ctrl->id) {
253	case V4L2_CID_AUDIO_MUTE:
254		radio->muted = ctrl->val;
255		return keene_cmd_main(radio, 0, true);
256
257	case V4L2_CID_TUNE_POWER_LEVEL:
258		/* To go from dBuV to the register value we apply the
259		   following formula: */
260		radio->pa = (ctrl->val - 71) * 100 / 62;
261		return keene_cmd_main(radio, 0, true);
262
263	case V4L2_CID_TUNE_PREEMPHASIS:
264		radio->preemph_75_us = ctrl->val == V4L2_PREEMPHASIS_75_uS;
265		return keene_cmd_set(radio);
266
267	case V4L2_CID_AUDIO_COMPRESSION_GAIN:
268		radio->tx = db2tx[(ctrl->val - (s32)ctrl->minimum) / (s32)ctrl->step];
269		return keene_cmd_set(radio);
270	}
271	return -EINVAL;
272}
273
274/* File system interface */
275static const struct v4l2_file_operations usb_keene_fops = {
276	.owner		= THIS_MODULE,
277	.open           = v4l2_fh_open,
278	.release        = v4l2_fh_release,
279	.poll		= v4l2_ctrl_poll,
280	.unlocked_ioctl	= video_ioctl2,
281};
282
283static const struct v4l2_ctrl_ops keene_ctrl_ops = {
284	.s_ctrl = keene_s_ctrl,
285};
286
287static const struct v4l2_ioctl_ops usb_keene_ioctl_ops = {
288	.vidioc_querycap    = vidioc_querycap,
289	.vidioc_g_modulator = vidioc_g_modulator,
290	.vidioc_s_modulator = vidioc_s_modulator,
291	.vidioc_g_frequency = vidioc_g_frequency,
292	.vidioc_s_frequency = vidioc_s_frequency,
293	.vidioc_log_status = v4l2_ctrl_log_status,
294	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
295	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
296};
297
298static void usb_keene_video_device_release(struct v4l2_device *v4l2_dev)
299{
300	struct keene_device *radio = to_keene_dev(v4l2_dev);
301
302	/* free rest memory */
303	v4l2_ctrl_handler_free(&radio->hdl);
304	kfree(radio->buffer);
305	kfree(radio);
306}
307
308/* check if the device is present and register with v4l and usb if it is */
309static int usb_keene_probe(struct usb_interface *intf,
310				const struct usb_device_id *id)
311{
312	struct usb_device *dev = interface_to_usbdev(intf);
313	struct keene_device *radio;
314	struct v4l2_ctrl_handler *hdl;
315	int retval = 0;
316
317	/*
318	 * The Keene FM transmitter USB device has the same USB ID as
319	 * the Logitech AudioHub Speaker, but it should ignore the hid.
320	 * Check if the name is that of the Keene device.
321	 * If not, then someone connected the AudioHub and we shouldn't
322	 * attempt to handle this driver.
323	 * For reference: the product name of the AudioHub is
324	 * "AudioHub Speaker".
325	 */
326	if (dev->product && strcmp(dev->product, "B-LINK USB Audio  "))
327		return -ENODEV;
328
329	radio = kzalloc(sizeof(struct keene_device), GFP_KERNEL);
330	if (radio)
331		radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);
332
333	if (!radio || !radio->buffer) {
334		dev_err(&intf->dev, "kmalloc for keene_device failed\n");
335		kfree(radio);
336		retval = -ENOMEM;
337		goto err;
338	}
339
340	hdl = &radio->hdl;
341	v4l2_ctrl_handler_init(hdl, 4);
342	v4l2_ctrl_new_std(hdl, &keene_ctrl_ops, V4L2_CID_AUDIO_MUTE,
343			0, 1, 1, 0);
344	v4l2_ctrl_new_std_menu(hdl, &keene_ctrl_ops, V4L2_CID_TUNE_PREEMPHASIS,
345			V4L2_PREEMPHASIS_75_uS, 1, V4L2_PREEMPHASIS_50_uS);
346	v4l2_ctrl_new_std(hdl, &keene_ctrl_ops, V4L2_CID_TUNE_POWER_LEVEL,
347			84, 118, 1, 118);
348	v4l2_ctrl_new_std(hdl, &keene_ctrl_ops, V4L2_CID_AUDIO_COMPRESSION_GAIN,
349			-15, 18, 3, 0);
350	radio->pa = 118;
351	radio->tx = 0x32;
352	radio->stereo = true;
353	if (hdl->error) {
354		retval = hdl->error;
355
356		v4l2_ctrl_handler_free(hdl);
357		goto err_v4l2;
358	}
359	retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
360	if (retval < 0) {
361		dev_err(&intf->dev, "couldn't register v4l2_device\n");
362		goto err_v4l2;
363	}
364
365	mutex_init(&radio->lock);
366
367	radio->v4l2_dev.ctrl_handler = hdl;
368	radio->v4l2_dev.release = usb_keene_video_device_release;
369	strlcpy(radio->vdev.name, radio->v4l2_dev.name,
370		sizeof(radio->vdev.name));
371	radio->vdev.v4l2_dev = &radio->v4l2_dev;
372	radio->vdev.fops = &usb_keene_fops;
373	radio->vdev.ioctl_ops = &usb_keene_ioctl_ops;
374	radio->vdev.lock = &radio->lock;
375	radio->vdev.release = video_device_release_empty;
376	radio->vdev.vfl_dir = VFL_DIR_TX;
377
378	radio->usbdev = interface_to_usbdev(intf);
379	radio->intf = intf;
380	usb_set_intfdata(intf, &radio->v4l2_dev);
381
382	video_set_drvdata(&radio->vdev, radio);
383
384	/* at least 11ms is needed in order to settle hardware */
385	msleep(20);
386	keene_cmd_main(radio, 95.16 * FREQ_MUL, false);
387
388	retval = video_register_device(&radio->vdev, VFL_TYPE_RADIO, -1);
389	if (retval < 0) {
390		dev_err(&intf->dev, "could not register video device\n");
391		goto err_vdev;
392	}
393	v4l2_ctrl_handler_setup(hdl);
394	dev_info(&intf->dev, "V4L2 device registered as %s\n",
395			video_device_node_name(&radio->vdev));
396	return 0;
397
398err_vdev:
399	v4l2_device_unregister(&radio->v4l2_dev);
400err_v4l2:
401	kfree(radio->buffer);
402	kfree(radio);
403err:
404	return retval;
405}
406
407/* USB subsystem interface */
408static struct usb_driver usb_keene_driver = {
409	.name			= "radio-keene",
410	.probe			= usb_keene_probe,
411	.disconnect		= usb_keene_disconnect,
412	.id_table		= usb_keene_device_table,
413	.suspend		= usb_keene_suspend,
414	.resume			= usb_keene_resume,
415	.reset_resume		= usb_keene_resume,
416};
417
418module_usb_driver(usb_keene_driver);
419
420