[media] radio-keene: add a driver for the Keene FM Transmitter
[deliverable/linux.git] / drivers / media / radio / radio-keene.c
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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/version.h>
32#include <linux/mutex.h>
33
34/* driver and module definitions */
35MODULE_AUTHOR("Hans Verkuil <hverkuil@xs4all.nl>");
36MODULE_DESCRIPTION("Keene FM Transmitter driver");
37MODULE_LICENSE("GPL");
38
39/* Actually, it advertises itself as a Logitech */
40#define USB_KEENE_VENDOR 0x046d
41#define USB_KEENE_PRODUCT 0x0a0e
42
43/* Probably USB_TIMEOUT should be modified in module parameter */
44#define BUFFER_LENGTH 8
45#define USB_TIMEOUT 500
46
47/* Frequency limits in MHz */
48#define FREQ_MIN 76U
49#define FREQ_MAX 108U
50#define FREQ_MUL 16000U
51
52/* USB Device ID List */
53static struct usb_device_id usb_keene_device_table[] = {
54 {USB_DEVICE_AND_INTERFACE_INFO(USB_KEENE_VENDOR, USB_KEENE_PRODUCT,
55 USB_CLASS_HID, 0, 0) },
56 { } /* Terminating entry */
57};
58
59MODULE_DEVICE_TABLE(usb, usb_keene_device_table);
60
61struct keene_device {
62 struct usb_device *usbdev;
63 struct usb_interface *intf;
64 struct video_device vdev;
65 struct v4l2_device v4l2_dev;
66 struct v4l2_ctrl_handler hdl;
67 struct mutex lock;
68
69 u8 *buffer;
70 unsigned curfreq;
71 u8 tx;
72 u8 pa;
73 bool stereo;
74 bool muted;
75 bool preemph_75_us;
76};
77
78static inline struct keene_device *to_keene_dev(struct v4l2_device *v4l2_dev)
79{
80 return container_of(v4l2_dev, struct keene_device, v4l2_dev);
81}
82
83/* Set frequency (if non-0), PA, mute and turn on/off the FM transmitter. */
84static int keene_cmd_main(struct keene_device *radio, unsigned freq, bool play)
85{
86 unsigned short freq_send = freq ? (freq - 76 * 16000) / 800 : 0;
87 int ret;
88
89 radio->buffer[0] = 0x00;
90 radio->buffer[1] = 0x50;
91 radio->buffer[2] = (freq_send >> 8) & 0xff;
92 radio->buffer[3] = freq_send & 0xff;
93 radio->buffer[4] = radio->pa;
94 /* If bit 4 is set, then tune to the frequency.
95 If bit 3 is set, then unmute; if bit 2 is set, then mute.
96 If bit 1 is set, then enter idle mode; if bit 0 is set,
97 then enter transit mode.
98 */
99 radio->buffer[5] = (radio->muted ? 4 : 8) | (play ? 1 : 2) |
100 (freq ? 0x10 : 0);
101 radio->buffer[6] = 0x00;
102 radio->buffer[7] = 0x00;
103
104 ret = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
105 9, 0x21, 0x200, 2, radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
106
107 if (ret < 0) {
108 dev_warn(&radio->vdev.dev, "%s failed (%d)\n", __func__, ret);
109 return ret;
110 }
111 if (freq)
112 radio->curfreq = freq;
113 return 0;
114}
115
116/* Set TX, stereo and preemphasis mode (50 us vs 75 us). */
117static int keene_cmd_set(struct keene_device *radio)
118{
119 int ret;
120
121 radio->buffer[0] = 0x00;
122 radio->buffer[1] = 0x51;
123 radio->buffer[2] = radio->tx;
124 /* If bit 0 is set, then transmit mono, otherwise stereo.
125 If bit 2 is set, then enable 75 us preemphasis, otherwise
126 it is 50 us. */
127 radio->buffer[3] = (!radio->stereo) | (radio->preemph_75_us ? 4 : 0);
128 radio->buffer[4] = 0x00;
129 radio->buffer[5] = 0x00;
130 radio->buffer[6] = 0x00;
131 radio->buffer[7] = 0x00;
132
133 ret = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
134 9, 0x21, 0x200, 2, radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
135
136 if (ret < 0) {
137 dev_warn(&radio->vdev.dev, "%s failed (%d)\n", __func__, ret);
138 return ret;
139 }
140 return 0;
141}
142
143/* Handle unplugging the device.
144 * We call video_unregister_device in any case.
145 * The last function called in this procedure is
146 * usb_keene_device_release.
147 */
148static void usb_keene_disconnect(struct usb_interface *intf)
149{
150 struct keene_device *radio = to_keene_dev(usb_get_intfdata(intf));
151
152 v4l2_device_get(&radio->v4l2_dev);
153 mutex_lock(&radio->lock);
154 usb_set_intfdata(intf, NULL);
155 video_unregister_device(&radio->vdev);
156 v4l2_device_disconnect(&radio->v4l2_dev);
157 mutex_unlock(&radio->lock);
158 v4l2_device_put(&radio->v4l2_dev);
159}
160
161static int vidioc_querycap(struct file *file, void *priv,
162 struct v4l2_capability *v)
163{
164 struct keene_device *radio = video_drvdata(file);
165
166 strlcpy(v->driver, "radio-keene", sizeof(v->driver));
167 strlcpy(v->card, "Keene FM Transmitter", sizeof(v->card));
168 usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
169 v->device_caps = V4L2_CAP_RADIO | V4L2_CAP_MODULATOR;
170 v->capabilities = v->device_caps | V4L2_CAP_DEVICE_CAPS;
171 return 0;
172}
173
174static int vidioc_g_modulator(struct file *file, void *priv,
175 struct v4l2_modulator *v)
176{
177 struct keene_device *radio = video_drvdata(file);
178
179 if (v->index > 0)
180 return -EINVAL;
181
182 strlcpy(v->name, "FM", sizeof(v->name));
183 v->rangelow = FREQ_MIN * FREQ_MUL;
184 v->rangehigh = FREQ_MAX * FREQ_MUL;
185 v->txsubchans = radio->stereo ? V4L2_TUNER_SUB_STEREO : V4L2_TUNER_SUB_MONO;
186 v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO;
187 return 0;
188}
189
190static int vidioc_s_modulator(struct file *file, void *priv,
191 struct v4l2_modulator *v)
192{
193 struct keene_device *radio = video_drvdata(file);
194
195 if (v->index > 0)
196 return -EINVAL;
197
198 radio->stereo = (v->txsubchans == V4L2_TUNER_SUB_STEREO);
199 return keene_cmd_set(radio);
200}
201
202static int vidioc_s_frequency(struct file *file, void *priv,
203 struct v4l2_frequency *f)
204{
205 struct keene_device *radio = video_drvdata(file);
206
207 if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
208 return -EINVAL;
209 f->frequency = clamp(f->frequency,
210 FREQ_MIN * FREQ_MUL, FREQ_MAX * FREQ_MUL);
211 return keene_cmd_main(radio, f->frequency, true);
212}
213
214static int vidioc_g_frequency(struct file *file, void *priv,
215 struct v4l2_frequency *f)
216{
217 struct keene_device *radio = video_drvdata(file);
218
219 if (f->tuner != 0)
220 return -EINVAL;
221 f->type = V4L2_TUNER_RADIO;
222 f->frequency = radio->curfreq;
223 return 0;
224}
225
226static int keene_s_ctrl(struct v4l2_ctrl *ctrl)
227{
228 static const u8 db2tx[] = {
229 /* -15, -12, -9, -6, -3, 0 dB */
230 0x03, 0x13, 0x02, 0x12, 0x22, 0x32,
231 /* 3, 6, 9, 12, 15, 18 dB */
232 0x21, 0x31, 0x20, 0x30, 0x40, 0x50
233 };
234 struct keene_device *radio =
235 container_of(ctrl->handler, struct keene_device, hdl);
236
237 switch (ctrl->id) {
238 case V4L2_CID_AUDIO_MUTE:
239 radio->muted = ctrl->val;
240 return keene_cmd_main(radio, 0, true);
241
242 case V4L2_CID_TUNE_POWER_LEVEL:
243 /* To go from dBuV to the register value we apply the
244 following formula: */
245 radio->pa = (ctrl->val - 71) * 100 / 62;
246 return keene_cmd_main(radio, 0, true);
247
248 case V4L2_CID_TUNE_PREEMPHASIS:
249 radio->preemph_75_us = ctrl->val == V4L2_PREEMPHASIS_75_uS;
250 return keene_cmd_set(radio);
251
252 case V4L2_CID_AUDIO_COMPRESSION_GAIN:
253 radio->tx = db2tx[(ctrl->val - ctrl->minimum) / ctrl->step];
254 return keene_cmd_set(radio);
255 }
256 return -EINVAL;
257}
258
259static int vidioc_subscribe_event(struct v4l2_fh *fh,
260 struct v4l2_event_subscription *sub)
261{
262 switch (sub->type) {
263 case V4L2_EVENT_CTRL:
264 return v4l2_event_subscribe(fh, sub, 0);
265 default:
266 return -EINVAL;
267 }
268}
269
270
271/* File system interface */
272static const struct v4l2_file_operations usb_keene_fops = {
273 .owner = THIS_MODULE,
274 .open = v4l2_fh_open,
275 .release = v4l2_fh_release,
276 .poll = v4l2_ctrl_poll,
277 .unlocked_ioctl = video_ioctl2,
278};
279
280static const struct v4l2_ctrl_ops keene_ctrl_ops = {
281 .s_ctrl = keene_s_ctrl,
282};
283
284static const struct v4l2_ioctl_ops usb_keene_ioctl_ops = {
285 .vidioc_querycap = vidioc_querycap,
286 .vidioc_g_modulator = vidioc_g_modulator,
287 .vidioc_s_modulator = vidioc_s_modulator,
288 .vidioc_g_frequency = vidioc_g_frequency,
289 .vidioc_s_frequency = vidioc_s_frequency,
290 .vidioc_log_status = v4l2_ctrl_log_status,
291 .vidioc_subscribe_event = vidioc_subscribe_event,
292 .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
293};
294
295static void usb_keene_video_device_release(struct v4l2_device *v4l2_dev)
296{
297 struct keene_device *radio = to_keene_dev(v4l2_dev);
298
299 /* free rest memory */
300 v4l2_ctrl_handler_free(&radio->hdl);
301 kfree(radio->buffer);
302 kfree(radio);
303}
304
305/* check if the device is present and register with v4l and usb if it is */
306static int usb_keene_probe(struct usb_interface *intf,
307 const struct usb_device_id *id)
308{
309 struct usb_device *dev = interface_to_usbdev(intf);
310 struct keene_device *radio;
311 struct v4l2_ctrl_handler *hdl;
312 int retval = 0;
313
314 /*
315 * The Keene FM transmitter USB device has the same USB ID as
316 * the Logitech AudioHub Speaker, but it should ignore the hid.
317 * Check if the name is that of the Keene device.
318 * If not, then someone connected the AudioHub and we shouldn't
319 * attempt to handle this driver.
320 * For reference: the product name of the AudioHub is
321 * "AudioHub Speaker".
322 */
323 if (dev->product && strcmp(dev->product, "B-LINK USB Audio "))
324 return -ENODEV;
325
326 radio = kzalloc(sizeof(struct keene_device), GFP_KERNEL);
327 if (radio)
328 radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);
329
330 if (!radio || !radio->buffer) {
331 dev_err(&intf->dev, "kmalloc for keene_device failed\n");
332 kfree(radio);
333 retval = -ENOMEM;
334 goto err;
335 }
336
337 hdl = &radio->hdl;
338 v4l2_ctrl_handler_init(hdl, 4);
339 v4l2_ctrl_new_std(hdl, &keene_ctrl_ops, V4L2_CID_AUDIO_MUTE,
340 0, 1, 1, 0);
341 v4l2_ctrl_new_std_menu(hdl, &keene_ctrl_ops, V4L2_CID_TUNE_PREEMPHASIS,
342 V4L2_PREEMPHASIS_75_uS, 1, V4L2_PREEMPHASIS_50_uS);
343 v4l2_ctrl_new_std(hdl, &keene_ctrl_ops, V4L2_CID_TUNE_POWER_LEVEL,
344 84, 118, 1, 118);
345 v4l2_ctrl_new_std(hdl, &keene_ctrl_ops, V4L2_CID_AUDIO_COMPRESSION_GAIN,
346 -15, 18, 3, 0);
347 radio->pa = 118;
348 radio->tx = 0x32;
349 radio->stereo = true;
350 radio->curfreq = 95.16 * FREQ_MUL;
351 if (hdl->error) {
352 retval = hdl->error;
353
354 v4l2_ctrl_handler_free(hdl);
355 goto err_v4l2;
356 }
357 retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
358 if (retval < 0) {
359 dev_err(&intf->dev, "couldn't register v4l2_device\n");
360 goto err_v4l2;
361 }
362
363 mutex_init(&radio->lock);
364
365 radio->v4l2_dev.ctrl_handler = hdl;
366 radio->v4l2_dev.release = usb_keene_video_device_release;
367 strlcpy(radio->vdev.name, radio->v4l2_dev.name,
368 sizeof(radio->vdev.name));
369 radio->vdev.v4l2_dev = &radio->v4l2_dev;
370 radio->vdev.fops = &usb_keene_fops;
371 radio->vdev.ioctl_ops = &usb_keene_ioctl_ops;
372 radio->vdev.lock = &radio->lock;
373 radio->vdev.release = video_device_release_empty;
374
375 radio->usbdev = interface_to_usbdev(intf);
376 radio->intf = intf;
377 usb_set_intfdata(intf, &radio->v4l2_dev);
378
379 video_set_drvdata(&radio->vdev, radio);
380 set_bit(V4L2_FL_USE_FH_PRIO, &radio->vdev.flags);
381
382 retval = video_register_device(&radio->vdev, VFL_TYPE_RADIO, -1);
383 if (retval < 0) {
384 dev_err(&intf->dev, "could not register video device\n");
385 goto err_vdev;
386 }
387 v4l2_ctrl_handler_setup(hdl);
388 dev_info(&intf->dev, "V4L2 device registered as %s\n",
389 video_device_node_name(&radio->vdev));
390 return 0;
391
392err_vdev:
393 v4l2_device_unregister(&radio->v4l2_dev);
394err_v4l2:
395 kfree(radio->buffer);
396 kfree(radio);
397err:
398 return retval;
399}
400
401/* USB subsystem interface */
402static struct usb_driver usb_keene_driver = {
403 .name = "radio-keene",
404 .probe = usb_keene_probe,
405 .disconnect = usb_keene_disconnect,
406 .id_table = usb_keene_device_table,
407};
408
409static int __init keene_init(void)
410{
411 int retval = usb_register(&usb_keene_driver);
412
413 if (retval)
414 pr_err(KBUILD_MODNAME
415 ": usb_register failed. Error number %d\n", retval);
416
417 return retval;
418}
419
420static void __exit keene_exit(void)
421{
422 usb_deregister(&usb_keene_driver);
423}
424
425module_init(keene_init);
426module_exit(keene_exit);
427
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