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 */
21MODULE_AUTHOR("Hans Verkuil <hverkuil@xs4all.nl>");
22MODULE_DESCRIPTION("Keene FM Transmitter driver");
23MODULE_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 */
39static 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
45MODULE_DEVICE_TABLE(usb, usb_keene_device_table);
46
47struct 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
64static 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. */
70static 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). */
103static 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 */
134static 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
146static 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
153static 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
163static 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
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	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
190static 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
202static 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
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 - (s32)ctrl->minimum) / (s32)ctrl->step];
254		return keene_cmd_set(radio);
255	}
256	return -EINVAL;
257}
258
259/* File system interface */
260static 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
268static const struct v4l2_ctrl_ops keene_ctrl_ops = {
269	.s_ctrl = keene_s_ctrl,
270};
271
272static 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
283static 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 */
294static 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
384err_vdev:
385	v4l2_device_unregister(&radio->v4l2_dev);
386err_v4l2:
387	kfree(radio->buffer);
388	kfree(radio);
389err:
390	return retval;
391}
392
393/* USB subsystem interface */
394static 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
404module_usb_driver(usb_keene_driver);
405
406