1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2012 Hans Verkuil <hverkuil@xs4all.nl>
4 */
5
6 /* kernel includes */
7 #include <linux/kernel.h>
8 #include <linux/module.h>
9 #include <linux/init.h>
10 #include <linux/slab.h>
11 #include <linux/input.h>
12 #include <linux/videodev2.h>
13 #include <media/v4l2-device.h>
14 #include <media/v4l2-ioctl.h>
15 #include <media/v4l2-ctrls.h>
16 #include <media/v4l2-event.h>
17 #include <linux/usb.h>
18 #include <linux/mutex.h>
19
20 /* driver and module definitions */
21 MODULE_AUTHOR("Hans Verkuil <hverkuil@xs4all.nl>");
22 MODULE_DESCRIPTION("Keene FM Transmitter driver");
23 MODULE_LICENSE("GPL");
24
25 /* Actually, it advertises itself as a Logitech */
26 #define USB_KEENE_VENDOR 0x046d
27 #define USB_KEENE_PRODUCT 0x0a0e
28
29 /* Probably USB_TIMEOUT should be modified in module parameter */
30 #define BUFFER_LENGTH 8
31 #define USB_TIMEOUT 500
32
33 /* Frequency limits in MHz */
34 #define FREQ_MIN 76U
35 #define FREQ_MAX 108U
36 #define FREQ_MUL 16000U
37
38 /* USB Device ID List */
39 static const struct usb_device_id usb_keene_device_table[] = {
40 {USB_DEVICE_AND_INTERFACE_INFO(USB_KEENE_VENDOR, USB_KEENE_PRODUCT,
41 USB_CLASS_HID, 0, 0) },
42 { } /* Terminating entry */
43 };
44
45 MODULE_DEVICE_TABLE(usb, usb_keene_device_table);
46
47 struct keene_device {
48 struct usb_device *usbdev;
49 struct usb_interface *intf;
50 struct video_device vdev;
51 struct v4l2_device v4l2_dev;
52 struct v4l2_ctrl_handler hdl;
53 struct mutex lock;
54
55 u8 *buffer;
56 unsigned curfreq;
57 u8 tx;
58 u8 pa;
59 bool stereo;
60 bool muted;
61 bool preemph_75_us;
62 };
63
to_keene_dev(struct v4l2_device * v4l2_dev)64 static inline struct keene_device *to_keene_dev(struct v4l2_device *v4l2_dev)
65 {
66 return container_of(v4l2_dev, struct keene_device, v4l2_dev);
67 }
68
69 /* 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)70 static int keene_cmd_main(struct keene_device *radio, unsigned freq, bool play)
71 {
72 unsigned short freq_send = freq ? (freq - 76 * 16000) / 800 : 0;
73 int ret;
74
75 radio->buffer[0] = 0x00;
76 radio->buffer[1] = 0x50;
77 radio->buffer[2] = (freq_send >> 8) & 0xff;
78 radio->buffer[3] = freq_send & 0xff;
79 radio->buffer[4] = radio->pa;
80 /* If bit 4 is set, then tune to the frequency.
81 If bit 3 is set, then unmute; if bit 2 is set, then mute.
82 If bit 1 is set, then enter idle mode; if bit 0 is set,
83 then enter transmit mode.
84 */
85 radio->buffer[5] = (radio->muted ? 4 : 8) | (play ? 1 : 2) |
86 (freq ? 0x10 : 0);
87 radio->buffer[6] = 0x00;
88 radio->buffer[7] = 0x00;
89
90 ret = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
91 9, 0x21, 0x200, 2, radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
92
93 if (ret < 0) {
94 dev_warn(&radio->vdev.dev, "%s failed (%d)\n", __func__, ret);
95 return ret;
96 }
97 if (freq)
98 radio->curfreq = freq;
99 return 0;
100 }
101
102 /* Set TX, stereo and preemphasis mode (50 us vs 75 us). */
keene_cmd_set(struct keene_device * radio)103 static int keene_cmd_set(struct keene_device *radio)
104 {
105 int ret;
106
107 radio->buffer[0] = 0x00;
108 radio->buffer[1] = 0x51;
109 radio->buffer[2] = radio->tx;
110 /* If bit 0 is set, then transmit mono, otherwise stereo.
111 If bit 2 is set, then enable 75 us preemphasis, otherwise
112 it is 50 us. */
113 radio->buffer[3] = (radio->stereo ? 0 : 1) | (radio->preemph_75_us ? 4 : 0);
114 radio->buffer[4] = 0x00;
115 radio->buffer[5] = 0x00;
116 radio->buffer[6] = 0x00;
117 radio->buffer[7] = 0x00;
118
119 ret = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
120 9, 0x21, 0x200, 2, radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
121
122 if (ret < 0) {
123 dev_warn(&radio->vdev.dev, "%s failed (%d)\n", __func__, ret);
124 return ret;
125 }
126 return 0;
127 }
128
129 /* Handle unplugging the device.
130 * We call video_unregister_device in any case.
131 * The last function called in this procedure is
132 * usb_keene_device_release.
133 */
usb_keene_disconnect(struct usb_interface * intf)134 static void usb_keene_disconnect(struct usb_interface *intf)
135 {
136 struct keene_device *radio = to_keene_dev(usb_get_intfdata(intf));
137
138 mutex_lock(&radio->lock);
139 usb_set_intfdata(intf, NULL);
140 video_unregister_device(&radio->vdev);
141 v4l2_device_disconnect(&radio->v4l2_dev);
142 mutex_unlock(&radio->lock);
143 v4l2_device_put(&radio->v4l2_dev);
144 }
145
usb_keene_suspend(struct usb_interface * intf,pm_message_t message)146 static int usb_keene_suspend(struct usb_interface *intf, pm_message_t message)
147 {
148 struct keene_device *radio = to_keene_dev(usb_get_intfdata(intf));
149
150 return keene_cmd_main(radio, 0, false);
151 }
152
usb_keene_resume(struct usb_interface * intf)153 static int usb_keene_resume(struct usb_interface *intf)
154 {
155 struct keene_device *radio = to_keene_dev(usb_get_intfdata(intf));
156
157 mdelay(50);
158 keene_cmd_set(radio);
159 keene_cmd_main(radio, radio->curfreq, true);
160 return 0;
161 }
162
vidioc_querycap(struct file * file,void * priv,struct v4l2_capability * v)163 static int vidioc_querycap(struct file *file, void *priv,
164 struct v4l2_capability *v)
165 {
166 struct keene_device *radio = video_drvdata(file);
167
168 strscpy(v->driver, "radio-keene", sizeof(v->driver));
169 strscpy(v->card, "Keene FM Transmitter", sizeof(v->card));
170 usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
171 return 0;
172 }
173
vidioc_g_modulator(struct file * file,void * priv,struct v4l2_modulator * v)174 static 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 strscpy(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
vidioc_s_modulator(struct file * file,void * priv,const struct v4l2_modulator * v)190 static int vidioc_s_modulator(struct file *file, void *priv,
191 const 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
vidioc_s_frequency(struct file * file,void * priv,const struct v4l2_frequency * f)202 static int vidioc_s_frequency(struct file *file, void *priv,
203 const struct v4l2_frequency *f)
204 {
205 struct keene_device *radio = video_drvdata(file);
206 unsigned freq = f->frequency;
207
208 if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
209 return -EINVAL;
210 freq = clamp(freq, FREQ_MIN * FREQ_MUL, FREQ_MAX * FREQ_MUL);
211 return keene_cmd_main(radio, freq, true);
212 }
213
vidioc_g_frequency(struct file * file,void * priv,struct v4l2_frequency * f)214 static 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
keene_s_ctrl(struct v4l2_ctrl * ctrl)226 static 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 - (s32)ctrl->minimum) / (s32)ctrl->step];
254 return keene_cmd_set(radio);
255 }
256 return -EINVAL;
257 }
258
259 /* File system interface */
260 static const struct v4l2_file_operations usb_keene_fops = {
261 .owner = THIS_MODULE,
262 .open = v4l2_fh_open,
263 .release = v4l2_fh_release,
264 .poll = v4l2_ctrl_poll,
265 .unlocked_ioctl = video_ioctl2,
266 };
267
268 static const struct v4l2_ctrl_ops keene_ctrl_ops = {
269 .s_ctrl = keene_s_ctrl,
270 };
271
272 static const struct v4l2_ioctl_ops usb_keene_ioctl_ops = {
273 .vidioc_querycap = vidioc_querycap,
274 .vidioc_g_modulator = vidioc_g_modulator,
275 .vidioc_s_modulator = vidioc_s_modulator,
276 .vidioc_g_frequency = vidioc_g_frequency,
277 .vidioc_s_frequency = vidioc_s_frequency,
278 .vidioc_log_status = v4l2_ctrl_log_status,
279 .vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
280 .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
281 };
282
usb_keene_video_device_release(struct v4l2_device * v4l2_dev)283 static void usb_keene_video_device_release(struct v4l2_device *v4l2_dev)
284 {
285 struct keene_device *radio = to_keene_dev(v4l2_dev);
286
287 /* free rest memory */
288 v4l2_ctrl_handler_free(&radio->hdl);
289 kfree(radio->buffer);
290 kfree(radio);
291 }
292
293 /* 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)294 static int usb_keene_probe(struct usb_interface *intf,
295 const struct usb_device_id *id)
296 {
297 struct usb_device *dev = interface_to_usbdev(intf);
298 struct keene_device *radio;
299 struct v4l2_ctrl_handler *hdl;
300 int retval = 0;
301
302 /*
303 * The Keene FM transmitter USB device has the same USB ID as
304 * the Logitech AudioHub Speaker, but it should ignore the hid.
305 * Check if the name is that of the Keene device.
306 * If not, then someone connected the AudioHub and we shouldn't
307 * attempt to handle this driver.
308 * For reference: the product name of the AudioHub is
309 * "AudioHub Speaker".
310 */
311 if (dev->product && strcmp(dev->product, "B-LINK USB Audio "))
312 return -ENODEV;
313
314 radio = kzalloc(sizeof(struct keene_device), GFP_KERNEL);
315 if (radio)
316 radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);
317
318 if (!radio || !radio->buffer) {
319 dev_err(&intf->dev, "kmalloc for keene_device failed\n");
320 kfree(radio);
321 retval = -ENOMEM;
322 goto err;
323 }
324
325 hdl = &radio->hdl;
326 v4l2_ctrl_handler_init(hdl, 4);
327 v4l2_ctrl_new_std(hdl, &keene_ctrl_ops, V4L2_CID_AUDIO_MUTE,
328 0, 1, 1, 0);
329 v4l2_ctrl_new_std_menu(hdl, &keene_ctrl_ops, V4L2_CID_TUNE_PREEMPHASIS,
330 V4L2_PREEMPHASIS_75_uS, 1, V4L2_PREEMPHASIS_50_uS);
331 v4l2_ctrl_new_std(hdl, &keene_ctrl_ops, V4L2_CID_TUNE_POWER_LEVEL,
332 84, 118, 1, 118);
333 v4l2_ctrl_new_std(hdl, &keene_ctrl_ops, V4L2_CID_AUDIO_COMPRESSION_GAIN,
334 -15, 18, 3, 0);
335 radio->pa = 118;
336 radio->tx = 0x32;
337 radio->stereo = true;
338 if (hdl->error) {
339 retval = hdl->error;
340
341 v4l2_ctrl_handler_free(hdl);
342 goto err_v4l2;
343 }
344 retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
345 if (retval < 0) {
346 dev_err(&intf->dev, "couldn't register v4l2_device\n");
347 goto err_v4l2;
348 }
349
350 mutex_init(&radio->lock);
351
352 radio->v4l2_dev.ctrl_handler = hdl;
353 radio->v4l2_dev.release = usb_keene_video_device_release;
354 strscpy(radio->vdev.name, radio->v4l2_dev.name,
355 sizeof(radio->vdev.name));
356 radio->vdev.v4l2_dev = &radio->v4l2_dev;
357 radio->vdev.fops = &usb_keene_fops;
358 radio->vdev.ioctl_ops = &usb_keene_ioctl_ops;
359 radio->vdev.lock = &radio->lock;
360 radio->vdev.release = video_device_release_empty;
361 radio->vdev.vfl_dir = VFL_DIR_TX;
362 radio->vdev.device_caps = V4L2_CAP_RADIO | V4L2_CAP_MODULATOR;
363
364 radio->usbdev = interface_to_usbdev(intf);
365 radio->intf = intf;
366 usb_set_intfdata(intf, &radio->v4l2_dev);
367
368 video_set_drvdata(&radio->vdev, radio);
369
370 /* at least 11ms is needed in order to settle hardware */
371 msleep(20);
372 keene_cmd_main(radio, 95.16 * FREQ_MUL, false);
373
374 retval = video_register_device(&radio->vdev, VFL_TYPE_RADIO, -1);
375 if (retval < 0) {
376 dev_err(&intf->dev, "could not register video device\n");
377 goto err_vdev;
378 }
379 v4l2_ctrl_handler_setup(hdl);
380 dev_info(&intf->dev, "V4L2 device registered as %s\n",
381 video_device_node_name(&radio->vdev));
382 return 0;
383
384 err_vdev:
385 v4l2_device_unregister(&radio->v4l2_dev);
386 err_v4l2:
387 kfree(radio->buffer);
388 kfree(radio);
389 err:
390 return retval;
391 }
392
393 /* USB subsystem interface */
394 static struct usb_driver usb_keene_driver = {
395 .name = "radio-keene",
396 .probe = usb_keene_probe,
397 .disconnect = usb_keene_disconnect,
398 .id_table = usb_keene_device_table,
399 .suspend = usb_keene_suspend,
400 .resume = usb_keene_resume,
401 .reset_resume = usb_keene_resume,
402 };
403
404 module_usb_driver(usb_keene_driver);
405
406
