1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2013 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
4  */
5 
6 #include <linux/kernel.h>
7 #include <linux/module.h>
8 #include <linux/init.h>
9 #include <linux/slab.h>
10 #include <linux/input.h>
11 #include <linux/usb.h>
12 #include <linux/hid.h>
13 #include <linux/mutex.h>
14 #include <linux/videodev2.h>
15 #include <asm/unaligned.h>
16 #include <media/v4l2-device.h>
17 #include <media/v4l2-ioctl.h>
18 #include <media/v4l2-ctrls.h>
19 #include <media/v4l2-event.h>
20 
21 /*
22  * 'Thanko's Raremono' is a Japanese si4734-based AM/FM/SW USB receiver:
23  *
24  * http://www.raremono.jp/product/484.html/
25  *
26  * The USB protocol has been reversed engineered using wireshark, initially
27  * by Dinesh Ram <dinesh.ram@cern.ch> and finished by Hans Verkuil
28  * <hverkuil@xs4all.nl>.
29  *
30  * Sadly the firmware used in this product hides lots of goodies since the
31  * si4734 has more features than are supported by the firmware. Oh well...
32  */
33 
34 /* driver and module definitions */
35 MODULE_AUTHOR("Hans Verkuil <hverkuil@xs4all.nl>");
36 MODULE_DESCRIPTION("Thanko's Raremono AM/FM/SW Receiver USB driver");
37 MODULE_LICENSE("GPL v2");
38 
39 /*
40  * The Device announces itself as Cygnal Integrated Products, Inc.
41  *
42  * The vendor and product IDs (and in fact all other lsusb information as
43  * well) are identical to the si470x Silicon Labs USB FM Radio Reference
44  * Design board, even though this card has a si4734 device. Clearly the
45  * designer of this product never bothered to change the USB IDs.
46  */
47 
48 /* USB Device ID List */
49 static const struct usb_device_id usb_raremono_device_table[] = {
50 	{USB_DEVICE_AND_INTERFACE_INFO(0x10c4, 0x818a, USB_CLASS_HID, 0, 0) },
51 	{ }						/* Terminating entry */
52 };
53 
54 MODULE_DEVICE_TABLE(usb, usb_raremono_device_table);
55 
56 #define BUFFER_LENGTH 64
57 
58 /* Timeout is set to a high value, could probably be reduced. Need more tests */
59 #define USB_TIMEOUT 10000
60 
61 /* Frequency limits in KHz */
62 #define FM_FREQ_RANGE_LOW	64000
63 #define FM_FREQ_RANGE_HIGH	108000
64 
65 #define AM_FREQ_RANGE_LOW	520
66 #define AM_FREQ_RANGE_HIGH	1710
67 
68 #define SW_FREQ_RANGE_LOW	2300
69 #define SW_FREQ_RANGE_HIGH	26100
70 
71 enum { BAND_FM, BAND_AM, BAND_SW };
72 
73 static const struct v4l2_frequency_band bands[] = {
74 	/* Band FM */
75 	{
76 		.type = V4L2_TUNER_RADIO,
77 		.index = 0,
78 		.capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
79 			      V4L2_TUNER_CAP_FREQ_BANDS,
80 		.rangelow   = FM_FREQ_RANGE_LOW * 16,
81 		.rangehigh  = FM_FREQ_RANGE_HIGH * 16,
82 		.modulation = V4L2_BAND_MODULATION_FM,
83 	},
84 	/* Band AM */
85 	{
86 		.type = V4L2_TUNER_RADIO,
87 		.index = 1,
88 		.capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_FREQ_BANDS,
89 		.rangelow   = AM_FREQ_RANGE_LOW * 16,
90 		.rangehigh  = AM_FREQ_RANGE_HIGH * 16,
91 		.modulation = V4L2_BAND_MODULATION_AM,
92 	},
93 	/* Band SW */
94 	{
95 		.type = V4L2_TUNER_RADIO,
96 		.index = 2,
97 		.capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_FREQ_BANDS,
98 		.rangelow   = SW_FREQ_RANGE_LOW * 16,
99 		.rangehigh  = SW_FREQ_RANGE_HIGH * 16,
100 		.modulation = V4L2_BAND_MODULATION_AM,
101 	},
102 };
103 
104 struct raremono_device {
105 	struct usb_device *usbdev;
106 	struct usb_interface *intf;
107 	struct video_device vdev;
108 	struct v4l2_device v4l2_dev;
109 	struct mutex lock;
110 
111 	u8 *buffer;
112 	u32 band;
113 	unsigned curfreq;
114 };
115 
116 static inline struct raremono_device *to_raremono_dev(struct v4l2_device *v4l2_dev)
117 {
118 	return container_of(v4l2_dev, struct raremono_device, v4l2_dev);
119 }
120 
121 /* Set frequency. */
122 static int raremono_cmd_main(struct raremono_device *radio, unsigned band, unsigned freq)
123 {
124 	unsigned band_offset;
125 	int ret;
126 
127 	switch (band) {
128 	case BAND_FM:
129 		band_offset = 1;
130 		freq /= 10;
131 		break;
132 	case BAND_AM:
133 		band_offset = 0;
134 		break;
135 	default:
136 		band_offset = 2;
137 		break;
138 	}
139 	radio->buffer[0] = 0x04 + band_offset;
140 	radio->buffer[1] = freq >> 8;
141 	radio->buffer[2] = freq & 0xff;
142 
143 	ret = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
144 			HID_REQ_SET_REPORT,
145 			USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
146 			0x0300 + radio->buffer[0], 2,
147 			radio->buffer, 3, USB_TIMEOUT);
148 
149 	if (ret < 0) {
150 		dev_warn(radio->v4l2_dev.dev, "%s failed (%d)\n", __func__, ret);
151 		return ret;
152 	}
153 	radio->curfreq = (band == BAND_FM) ? freq * 10 : freq;
154 	return 0;
155 }
156 
157 /* Handle unplugging the device.
158  * We call video_unregister_device in any case.
159  * The last function called in this procedure is
160  * usb_raremono_device_release.
161  */
162 static void usb_raremono_disconnect(struct usb_interface *intf)
163 {
164 	struct raremono_device *radio = to_raremono_dev(usb_get_intfdata(intf));
165 
166 	dev_info(&intf->dev, "Thanko's Raremono disconnected\n");
167 
168 	mutex_lock(&radio->lock);
169 	usb_set_intfdata(intf, NULL);
170 	video_unregister_device(&radio->vdev);
171 	v4l2_device_disconnect(&radio->v4l2_dev);
172 	mutex_unlock(&radio->lock);
173 	v4l2_device_put(&radio->v4l2_dev);
174 }
175 
176 /*
177  * Linux Video interface
178  */
179 static int vidioc_querycap(struct file *file, void *priv,
180 					struct v4l2_capability *v)
181 {
182 	struct raremono_device *radio = video_drvdata(file);
183 
184 	strscpy(v->driver, "radio-raremono", sizeof(v->driver));
185 	strscpy(v->card, "Thanko's Raremono", sizeof(v->card));
186 	usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
187 	v->device_caps = V4L2_CAP_TUNER | V4L2_CAP_RADIO;
188 	v->capabilities = v->device_caps | V4L2_CAP_DEVICE_CAPS;
189 	return 0;
190 }
191 
192 static int vidioc_enum_freq_bands(struct file *file, void *priv,
193 		struct v4l2_frequency_band *band)
194 {
195 	if (band->tuner != 0)
196 		return -EINVAL;
197 
198 	if (band->index >= ARRAY_SIZE(bands))
199 		return -EINVAL;
200 
201 	*band = bands[band->index];
202 
203 	return 0;
204 }
205 
206 static int vidioc_g_tuner(struct file *file, void *priv,
207 		struct v4l2_tuner *v)
208 {
209 	struct raremono_device *radio = video_drvdata(file);
210 	int ret;
211 
212 	if (v->index > 0)
213 		return -EINVAL;
214 
215 	strscpy(v->name, "AM/FM/SW", sizeof(v->name));
216 	v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
217 		V4L2_TUNER_CAP_FREQ_BANDS;
218 	v->rangelow = AM_FREQ_RANGE_LOW * 16;
219 	v->rangehigh = FM_FREQ_RANGE_HIGH * 16;
220 	v->rxsubchans = V4L2_TUNER_SUB_STEREO | V4L2_TUNER_SUB_MONO;
221 	v->audmode = (radio->curfreq < FM_FREQ_RANGE_LOW) ?
222 		V4L2_TUNER_MODE_MONO : V4L2_TUNER_MODE_STEREO;
223 	memset(radio->buffer, 1, BUFFER_LENGTH);
224 	ret = usb_control_msg(radio->usbdev, usb_rcvctrlpipe(radio->usbdev, 0),
225 			1, 0xa1, 0x030d, 2, radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
226 
227 	if (ret < 0) {
228 		dev_warn(radio->v4l2_dev.dev, "%s failed (%d)\n", __func__, ret);
229 		return ret;
230 	}
231 	v->signal = ((radio->buffer[1] & 0xf) << 8 | radio->buffer[2]) << 4;
232 	return 0;
233 }
234 
235 static int vidioc_s_tuner(struct file *file, void *priv,
236 					const struct v4l2_tuner *v)
237 {
238 	return v->index ? -EINVAL : 0;
239 }
240 
241 static int vidioc_s_frequency(struct file *file, void *priv,
242 				const struct v4l2_frequency *f)
243 {
244 	struct raremono_device *radio = video_drvdata(file);
245 	u32 freq;
246 	unsigned band;
247 
248 	if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
249 		return -EINVAL;
250 
251 	if (f->frequency >= (FM_FREQ_RANGE_LOW + SW_FREQ_RANGE_HIGH) * 8)
252 		band = BAND_FM;
253 	else if (f->frequency <= (AM_FREQ_RANGE_HIGH + SW_FREQ_RANGE_LOW) * 8)
254 		band = BAND_AM;
255 	else
256 		band = BAND_SW;
257 
258 	freq = clamp_t(u32, f->frequency, bands[band].rangelow, bands[band].rangehigh);
259 	return raremono_cmd_main(radio, band, freq / 16);
260 }
261 
262 static int vidioc_g_frequency(struct file *file, void *priv,
263 				struct v4l2_frequency *f)
264 {
265 	struct raremono_device *radio = video_drvdata(file);
266 
267 	if (f->tuner != 0)
268 		return -EINVAL;
269 	f->type = V4L2_TUNER_RADIO;
270 	f->frequency = radio->curfreq * 16;
271 	return 0;
272 }
273 
274 /* File system interface */
275 static const struct v4l2_file_operations usb_raremono_fops = {
276 	.owner		= THIS_MODULE,
277 	.open           = v4l2_fh_open,
278 	.release        = v4l2_fh_release,
279 	.unlocked_ioctl	= video_ioctl2,
280 };
281 
282 static const struct v4l2_ioctl_ops usb_raremono_ioctl_ops = {
283 	.vidioc_querycap = vidioc_querycap,
284 	.vidioc_g_tuner = vidioc_g_tuner,
285 	.vidioc_s_tuner = vidioc_s_tuner,
286 	.vidioc_g_frequency = vidioc_g_frequency,
287 	.vidioc_s_frequency = vidioc_s_frequency,
288 	.vidioc_enum_freq_bands = vidioc_enum_freq_bands,
289 };
290 
291 /* check if the device is present and register with v4l and usb if it is */
292 static int usb_raremono_probe(struct usb_interface *intf,
293 				const struct usb_device_id *id)
294 {
295 	struct raremono_device *radio;
296 	int retval = 0;
297 
298 	radio = devm_kzalloc(&intf->dev, sizeof(struct raremono_device), GFP_KERNEL);
299 	if (radio)
300 		radio->buffer = devm_kmalloc(&intf->dev, BUFFER_LENGTH, GFP_KERNEL);
301 
302 	if (!radio || !radio->buffer)
303 		return -ENOMEM;
304 
305 	radio->usbdev = interface_to_usbdev(intf);
306 	radio->intf = intf;
307 
308 	/*
309 	 * This device uses the same USB IDs as the si470x SiLabs reference
310 	 * design. So do an additional check: attempt to read the device ID
311 	 * from the si470x: the lower 12 bits are 0x0242 for the si470x. The
312 	 * Raremono always returns 0x0800 (the meaning of that is unknown, but
313 	 * at least it works).
314 	 *
315 	 * We use this check to determine which device we are dealing with.
316 	 */
317 	msleep(20);
318 	retval = usb_control_msg(radio->usbdev,
319 		usb_rcvctrlpipe(radio->usbdev, 0),
320 		HID_REQ_GET_REPORT,
321 		USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
322 		1, 2,
323 		radio->buffer, 3, 500);
324 	if (retval != 3 ||
325 	    (get_unaligned_be16(&radio->buffer[1]) & 0xfff) == 0x0242) {
326 		dev_info(&intf->dev, "this is not Thanko's Raremono.\n");
327 		return -ENODEV;
328 	}
329 
330 	dev_info(&intf->dev, "Thanko's Raremono connected: (%04X:%04X)\n",
331 			id->idVendor, id->idProduct);
332 
333 	retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
334 	if (retval < 0) {
335 		dev_err(&intf->dev, "couldn't register v4l2_device\n");
336 		return retval;
337 	}
338 
339 	mutex_init(&radio->lock);
340 
341 	strscpy(radio->vdev.name, radio->v4l2_dev.name,
342 		sizeof(radio->vdev.name));
343 	radio->vdev.v4l2_dev = &radio->v4l2_dev;
344 	radio->vdev.fops = &usb_raremono_fops;
345 	radio->vdev.ioctl_ops = &usb_raremono_ioctl_ops;
346 	radio->vdev.lock = &radio->lock;
347 	radio->vdev.release = video_device_release_empty;
348 
349 	usb_set_intfdata(intf, &radio->v4l2_dev);
350 
351 	video_set_drvdata(&radio->vdev, radio);
352 
353 	raremono_cmd_main(radio, BAND_FM, 95160);
354 
355 	retval = video_register_device(&radio->vdev, VFL_TYPE_RADIO, -1);
356 	if (retval == 0) {
357 		dev_info(&intf->dev, "V4L2 device registered as %s\n",
358 				video_device_node_name(&radio->vdev));
359 		return 0;
360 	}
361 	dev_err(&intf->dev, "could not register video device\n");
362 	v4l2_device_unregister(&radio->v4l2_dev);
363 	return retval;
364 }
365 
366 /* USB subsystem interface */
367 static struct usb_driver usb_raremono_driver = {
368 	.name			= "radio-raremono",
369 	.probe			= usb_raremono_probe,
370 	.disconnect		= usb_raremono_disconnect,
371 	.id_table		= usb_raremono_device_table,
372 };
373 
374 module_usb_driver(usb_raremono_driver);
375