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
15 /* kernel includes */
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/init.h>
19 #include <linux/slab.h>
20 #include <linux/input.h>
21 #include <linux/videodev2.h>
22 #include <media/v4l2-device.h>
23 #include <media/v4l2-ioctl.h>
24 #include <media/v4l2-ctrls.h>
25 #include <media/v4l2-event.h>
26 #include <linux/usb.h>
27 #include <linux/mutex.h>
28
29 /* driver and module definitions */
30 MODULE_AUTHOR("Hans Verkuil <hverkuil@xs4all.nl>");
31 MODULE_DESCRIPTION("Keene FM Transmitter driver");
32 MODULE_LICENSE("GPL");
33
34 /* Actually, it advertises itself as a Logitech */
35 #define USB_KEENE_VENDOR 0x046d
36 #define USB_KEENE_PRODUCT 0x0a0e
37
38 /* Probably USB_TIMEOUT should be modified in module parameter */
39 #define BUFFER_LENGTH 8
40 #define USB_TIMEOUT 500
41
42 /* Frequency limits in MHz */
43 #define FREQ_MIN 76U
44 #define FREQ_MAX 108U
45 #define FREQ_MUL 16000U
46
47 /* USB Device ID List */
48 static const struct usb_device_id usb_keene_device_table[] = {
49 {USB_DEVICE_AND_INTERFACE_INFO(USB_KEENE_VENDOR, USB_KEENE_PRODUCT,
50 USB_CLASS_HID, 0, 0) },
51 { } /* Terminating entry */
52 };
53
54 MODULE_DEVICE_TABLE(usb, usb_keene_device_table);
55
56 struct keene_device {
57 struct usb_device *usbdev;
58 struct usb_interface *intf;
59 struct video_device vdev;
60 struct v4l2_device v4l2_dev;
61 struct v4l2_ctrl_handler hdl;
62 struct mutex lock;
63
64 u8 *buffer;
65 unsigned curfreq;
66 u8 tx;
67 u8 pa;
68 bool stereo;
69 bool muted;
70 bool preemph_75_us;
71 };
72
to_keene_dev(struct v4l2_device * v4l2_dev)73 static inline struct keene_device *to_keene_dev(struct v4l2_device *v4l2_dev)
74 {
75 return container_of(v4l2_dev, struct keene_device, v4l2_dev);
76 }
77
78 /* Set frequency (if non-0), PA, mute and turn on/off the FM transmitter. */
keene_cmd_main(struct keene_device * radio,unsigned freq,bool play)79 static int keene_cmd_main(struct keene_device *radio, unsigned freq, bool play)
80 {
81 unsigned short freq_send = freq ? (freq - 76 * 16000) / 800 : 0;
82 int ret;
83
84 radio->buffer[0] = 0x00;
85 radio->buffer[1] = 0x50;
86 radio->buffer[2] = (freq_send >> 8) & 0xff;
87 radio->buffer[3] = freq_send & 0xff;
88 radio->buffer[4] = radio->pa;
89 /* If bit 4 is set, then tune to the frequency.
90 If bit 3 is set, then unmute; if bit 2 is set, then mute.
91 If bit 1 is set, then enter idle mode; if bit 0 is set,
92 then enter transmit mode.
93 */
94 radio->buffer[5] = (radio->muted ? 4 : 8) | (play ? 1 : 2) |
95 (freq ? 0x10 : 0);
96 radio->buffer[6] = 0x00;
97 radio->buffer[7] = 0x00;
98
99 ret = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
100 9, 0x21, 0x200, 2, radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
101
102 if (ret < 0) {
103 dev_warn(&radio->vdev.dev, "%s failed (%d)\n", __func__, ret);
104 return ret;
105 }
106 if (freq)
107 radio->curfreq = freq;
108 return 0;
109 }
110
111 /* Set TX, stereo and preemphasis mode (50 us vs 75 us). */
keene_cmd_set(struct keene_device * radio)112 static int keene_cmd_set(struct keene_device *radio)
113 {
114 int ret;
115
116 radio->buffer[0] = 0x00;
117 radio->buffer[1] = 0x51;
118 radio->buffer[2] = radio->tx;
119 /* If bit 0 is set, then transmit mono, otherwise stereo.
120 If bit 2 is set, then enable 75 us preemphasis, otherwise
121 it is 50 us. */
122 radio->buffer[3] = (radio->stereo ? 0 : 1) | (radio->preemph_75_us ? 4 : 0);
123 radio->buffer[4] = 0x00;
124 radio->buffer[5] = 0x00;
125 radio->buffer[6] = 0x00;
126 radio->buffer[7] = 0x00;
127
128 ret = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
129 9, 0x21, 0x200, 2, radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
130
131 if (ret < 0) {
132 dev_warn(&radio->vdev.dev, "%s failed (%d)\n", __func__, ret);
133 return ret;
134 }
135 return 0;
136 }
137
138 /* Handle unplugging the device.
139 * We call video_unregister_device in any case.
140 * The last function called in this procedure is
141 * usb_keene_device_release.
142 */
usb_keene_disconnect(struct usb_interface * intf)143 static void usb_keene_disconnect(struct usb_interface *intf)
144 {
145 struct keene_device *radio = to_keene_dev(usb_get_intfdata(intf));
146
147 mutex_lock(&radio->lock);
148 usb_set_intfdata(intf, NULL);
149 video_unregister_device(&radio->vdev);
150 v4l2_device_disconnect(&radio->v4l2_dev);
151 mutex_unlock(&radio->lock);
152 v4l2_device_put(&radio->v4l2_dev);
153 }
154
usb_keene_suspend(struct usb_interface * intf,pm_message_t message)155 static int usb_keene_suspend(struct usb_interface *intf, pm_message_t message)
156 {
157 struct keene_device *radio = to_keene_dev(usb_get_intfdata(intf));
158
159 return keene_cmd_main(radio, 0, false);
160 }
161
usb_keene_resume(struct usb_interface * intf)162 static int usb_keene_resume(struct usb_interface *intf)
163 {
164 struct keene_device *radio = to_keene_dev(usb_get_intfdata(intf));
165
166 mdelay(50);
167 keene_cmd_set(radio);
168 keene_cmd_main(radio, radio->curfreq, true);
169 return 0;
170 }
171
vidioc_querycap(struct file * file,void * priv,struct v4l2_capability * v)172 static int vidioc_querycap(struct file *file, void *priv,
173 struct v4l2_capability *v)
174 {
175 struct keene_device *radio = video_drvdata(file);
176
177 strlcpy(v->driver, "radio-keene", sizeof(v->driver));
178 strlcpy(v->card, "Keene FM Transmitter", 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_MODULATOR;
181 v->capabilities = v->device_caps | V4L2_CAP_DEVICE_CAPS;
182 return 0;
183 }
184
vidioc_g_modulator(struct file * file,void * priv,struct v4l2_modulator * v)185 static int vidioc_g_modulator(struct file *file, void *priv,
186 struct v4l2_modulator *v)
187 {
188 struct keene_device *radio = video_drvdata(file);
189
190 if (v->index > 0)
191 return -EINVAL;
192
193 strlcpy(v->name, "FM", sizeof(v->name));
194 v->rangelow = FREQ_MIN * FREQ_MUL;
195 v->rangehigh = FREQ_MAX * FREQ_MUL;
196 v->txsubchans = radio->stereo ? V4L2_TUNER_SUB_STEREO : V4L2_TUNER_SUB_MONO;
197 v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO;
198 return 0;
199 }
200
vidioc_s_modulator(struct file * file,void * priv,const struct v4l2_modulator * v)201 static int vidioc_s_modulator(struct file *file, void *priv,
202 const struct v4l2_modulator *v)
203 {
204 struct keene_device *radio = video_drvdata(file);
205
206 if (v->index > 0)
207 return -EINVAL;
208
209 radio->stereo = (v->txsubchans == V4L2_TUNER_SUB_STEREO);
210 return keene_cmd_set(radio);
211 }
212
vidioc_s_frequency(struct file * file,void * priv,const struct v4l2_frequency * f)213 static int vidioc_s_frequency(struct file *file, void *priv,
214 const struct v4l2_frequency *f)
215 {
216 struct keene_device *radio = video_drvdata(file);
217 unsigned freq = f->frequency;
218
219 if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
220 return -EINVAL;
221 freq = clamp(freq, FREQ_MIN * FREQ_MUL, FREQ_MAX * FREQ_MUL);
222 return keene_cmd_main(radio, freq, true);
223 }
224
vidioc_g_frequency(struct file * file,void * priv,struct v4l2_frequency * f)225 static int vidioc_g_frequency(struct file *file, void *priv,
226 struct v4l2_frequency *f)
227 {
228 struct keene_device *radio = video_drvdata(file);
229
230 if (f->tuner != 0)
231 return -EINVAL;
232 f->type = V4L2_TUNER_RADIO;
233 f->frequency = radio->curfreq;
234 return 0;
235 }
236
keene_s_ctrl(struct v4l2_ctrl * ctrl)237 static int keene_s_ctrl(struct v4l2_ctrl *ctrl)
238 {
239 static const u8 db2tx[] = {
240 /* -15, -12, -9, -6, -3, 0 dB */
241 0x03, 0x13, 0x02, 0x12, 0x22, 0x32,
242 /* 3, 6, 9, 12, 15, 18 dB */
243 0x21, 0x31, 0x20, 0x30, 0x40, 0x50
244 };
245 struct keene_device *radio =
246 container_of(ctrl->handler, struct keene_device, hdl);
247
248 switch (ctrl->id) {
249 case V4L2_CID_AUDIO_MUTE:
250 radio->muted = ctrl->val;
251 return keene_cmd_main(radio, 0, true);
252
253 case V4L2_CID_TUNE_POWER_LEVEL:
254 /* To go from dBuV to the register value we apply the
255 following formula: */
256 radio->pa = (ctrl->val - 71) * 100 / 62;
257 return keene_cmd_main(radio, 0, true);
258
259 case V4L2_CID_TUNE_PREEMPHASIS:
260 radio->preemph_75_us = ctrl->val == V4L2_PREEMPHASIS_75_uS;
261 return keene_cmd_set(radio);
262
263 case V4L2_CID_AUDIO_COMPRESSION_GAIN:
264 radio->tx = db2tx[(ctrl->val - (s32)ctrl->minimum) / (s32)ctrl->step];
265 return keene_cmd_set(radio);
266 }
267 return -EINVAL;
268 }
269
270 /* File system interface */
271 static const struct v4l2_file_operations usb_keene_fops = {
272 .owner = THIS_MODULE,
273 .open = v4l2_fh_open,
274 .release = v4l2_fh_release,
275 .poll = v4l2_ctrl_poll,
276 .unlocked_ioctl = video_ioctl2,
277 };
278
279 static const struct v4l2_ctrl_ops keene_ctrl_ops = {
280 .s_ctrl = keene_s_ctrl,
281 };
282
283 static const struct v4l2_ioctl_ops usb_keene_ioctl_ops = {
284 .vidioc_querycap = vidioc_querycap,
285 .vidioc_g_modulator = vidioc_g_modulator,
286 .vidioc_s_modulator = vidioc_s_modulator,
287 .vidioc_g_frequency = vidioc_g_frequency,
288 .vidioc_s_frequency = vidioc_s_frequency,
289 .vidioc_log_status = v4l2_ctrl_log_status,
290 .vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
291 .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
292 };
293
usb_keene_video_device_release(struct v4l2_device * v4l2_dev)294 static void usb_keene_video_device_release(struct v4l2_device *v4l2_dev)
295 {
296 struct keene_device *radio = to_keene_dev(v4l2_dev);
297
298 /* free rest memory */
299 v4l2_ctrl_handler_free(&radio->hdl);
300 kfree(radio->buffer);
301 kfree(radio);
302 }
303
304 /* check if the device is present and register with v4l and usb if it is */
usb_keene_probe(struct usb_interface * intf,const struct usb_device_id * id)305 static int usb_keene_probe(struct usb_interface *intf,
306 const struct usb_device_id *id)
307 {
308 struct usb_device *dev = interface_to_usbdev(intf);
309 struct keene_device *radio;
310 struct v4l2_ctrl_handler *hdl;
311 int retval = 0;
312
313 /*
314 * The Keene FM transmitter USB device has the same USB ID as
315 * the Logitech AudioHub Speaker, but it should ignore the hid.
316 * Check if the name is that of the Keene device.
317 * If not, then someone connected the AudioHub and we shouldn't
318 * attempt to handle this driver.
319 * For reference: the product name of the AudioHub is
320 * "AudioHub Speaker".
321 */
322 if (dev->product && strcmp(dev->product, "B-LINK USB Audio "))
323 return -ENODEV;
324
325 radio = kzalloc(sizeof(struct keene_device), GFP_KERNEL);
326 if (radio)
327 radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);
328
329 if (!radio || !radio->buffer) {
330 dev_err(&intf->dev, "kmalloc for keene_device failed\n");
331 kfree(radio);
332 retval = -ENOMEM;
333 goto err;
334 }
335
336 hdl = &radio->hdl;
337 v4l2_ctrl_handler_init(hdl, 4);
338 v4l2_ctrl_new_std(hdl, &keene_ctrl_ops, V4L2_CID_AUDIO_MUTE,
339 0, 1, 1, 0);
340 v4l2_ctrl_new_std_menu(hdl, &keene_ctrl_ops, V4L2_CID_TUNE_PREEMPHASIS,
341 V4L2_PREEMPHASIS_75_uS, 1, V4L2_PREEMPHASIS_50_uS);
342 v4l2_ctrl_new_std(hdl, &keene_ctrl_ops, V4L2_CID_TUNE_POWER_LEVEL,
343 84, 118, 1, 118);
344 v4l2_ctrl_new_std(hdl, &keene_ctrl_ops, V4L2_CID_AUDIO_COMPRESSION_GAIN,
345 -15, 18, 3, 0);
346 radio->pa = 118;
347 radio->tx = 0x32;
348 radio->stereo = true;
349 if (hdl->error) {
350 retval = hdl->error;
351
352 v4l2_ctrl_handler_free(hdl);
353 goto err_v4l2;
354 }
355 retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
356 if (retval < 0) {
357 dev_err(&intf->dev, "couldn't register v4l2_device\n");
358 goto err_v4l2;
359 }
360
361 mutex_init(&radio->lock);
362
363 radio->v4l2_dev.ctrl_handler = hdl;
364 radio->v4l2_dev.release = usb_keene_video_device_release;
365 strlcpy(radio->vdev.name, radio->v4l2_dev.name,
366 sizeof(radio->vdev.name));
367 radio->vdev.v4l2_dev = &radio->v4l2_dev;
368 radio->vdev.fops = &usb_keene_fops;
369 radio->vdev.ioctl_ops = &usb_keene_ioctl_ops;
370 radio->vdev.lock = &radio->lock;
371 radio->vdev.release = video_device_release_empty;
372 radio->vdev.vfl_dir = VFL_DIR_TX;
373
374 radio->usbdev = interface_to_usbdev(intf);
375 radio->intf = intf;
376 usb_set_intfdata(intf, &radio->v4l2_dev);
377
378 video_set_drvdata(&radio->vdev, radio);
379
380 /* at least 11ms is needed in order to settle hardware */
381 msleep(20);
382 keene_cmd_main(radio, 95.16 * FREQ_MUL, false);
383
384 retval = video_register_device(&radio->vdev, VFL_TYPE_RADIO, -1);
385 if (retval < 0) {
386 dev_err(&intf->dev, "could not register video device\n");
387 goto err_vdev;
388 }
389 v4l2_ctrl_handler_setup(hdl);
390 dev_info(&intf->dev, "V4L2 device registered as %s\n",
391 video_device_node_name(&radio->vdev));
392 return 0;
393
394 err_vdev:
395 v4l2_device_unregister(&radio->v4l2_dev);
396 err_v4l2:
397 kfree(radio->buffer);
398 kfree(radio);
399 err:
400 return retval;
401 }
402
403 /* USB subsystem interface */
404 static struct usb_driver usb_keene_driver = {
405 .name = "radio-keene",
406 .probe = usb_keene_probe,
407 .disconnect = usb_keene_disconnect,
408 .id_table = usb_keene_device_table,
409 .suspend = usb_keene_suspend,
410 .resume = usb_keene_resume,
411 .reset_resume = usb_keene_resume,
412 };
413
414 module_usb_driver(usb_keene_driver);
415
416
