1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Driver for the MasterKit MA901 USB FM radio. This device plugs
4 * into the USB port and an analog audio input or headphones, so this thing
5 * only deals with initialization, frequency setting, volume.
6 *
7 * Copyright (c) 2012 Alexey Klimov <klimov.linux@gmail.com>
8 */
9
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/init.h>
13#include <linux/slab.h>
14#include <linux/input.h>
15#include <linux/videodev2.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#include <linux/usb.h>
21#include <linux/mutex.h>
22
23#define DRIVER_AUTHOR "Alexey Klimov <klimov.linux@gmail.com>"
24#define DRIVER_DESC "Masterkit MA901 USB FM radio driver"
25#define DRIVER_VERSION "0.0.1"
26
27MODULE_AUTHOR(DRIVER_AUTHOR);
28MODULE_DESCRIPTION(DRIVER_DESC);
29MODULE_LICENSE("GPL");
30MODULE_VERSION(DRIVER_VERSION);
31
32#define USB_MA901_VENDOR  0x16c0
33#define USB_MA901_PRODUCT 0x05df
34
35/* dev_warn macro with driver name */
36#define MA901_DRIVER_NAME "radio-ma901"
37#define ma901radio_dev_warn(dev, fmt, arg...)				\
38		dev_warn(dev, MA901_DRIVER_NAME " - " fmt, ##arg)
39
40#define ma901radio_dev_err(dev, fmt, arg...) \
41		dev_err(dev, MA901_DRIVER_NAME " - " fmt, ##arg)
42
43/* Probably USB_TIMEOUT should be modified in module parameter */
44#define BUFFER_LENGTH 8
45#define USB_TIMEOUT 500
46
47#define FREQ_MIN  87.5
48#define FREQ_MAX 108.0
49#define FREQ_MUL 16000
50
51#define MA901_VOLUME_MAX 16
52#define MA901_VOLUME_MIN 0
53
54/* Commands that device should understand
55 * List isn't full and will be updated with implementation of new functions
56 */
57#define MA901_RADIO_SET_FREQ		0x03
58#define MA901_RADIO_SET_VOLUME		0x04
59#define MA901_RADIO_SET_MONO_STEREO	0x05
60
61/* Comfortable defines for ma901radio_set_stereo */
62#define MA901_WANT_STEREO		0x50
63#define MA901_WANT_MONO			0xd0
64
65/* module parameter */
66static int radio_nr = -1;
67module_param(radio_nr, int, 0);
68MODULE_PARM_DESC(radio_nr, "Radio file number");
69
70/* Data for one (physical) device */
71struct ma901radio_device {
72	/* reference to USB and video device */
73	struct usb_device *usbdev;
74	struct usb_interface *intf;
75	struct video_device vdev;
76	struct v4l2_device v4l2_dev;
77	struct v4l2_ctrl_handler hdl;
78
79	u8 *buffer;
80	struct mutex lock;	/* buffer locking */
81	int curfreq;
82	u16 volume;
83	int stereo;
84	bool muted;
85};
86
87static inline struct ma901radio_device *to_ma901radio_dev(struct v4l2_device *v4l2_dev)
88{
89	return container_of(v4l2_dev, struct ma901radio_device, v4l2_dev);
90}
91
92/* set a frequency, freq is defined by v4l's TUNER_LOW, i.e. 1/16th kHz */
93static int ma901radio_set_freq(struct ma901radio_device *radio, int freq)
94{
95	unsigned int freq_send = 0x300 + (freq >> 5) / 25;
96	int retval;
97
98	radio->buffer[0] = 0x0a;
99	radio->buffer[1] = MA901_RADIO_SET_FREQ;
100	radio->buffer[2] = ((freq_send >> 8) & 0xff) + 0x80;
101	radio->buffer[3] = freq_send & 0xff;
102	radio->buffer[4] = 0x00;
103	radio->buffer[5] = 0x00;
104	radio->buffer[6] = 0x00;
105	radio->buffer[7] = 0x00;
106
107	retval = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
108				9, 0x21, 0x0300, 0,
109				radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
110	if (retval < 0)
111		return retval;
112
113	radio->curfreq = freq;
114	return 0;
115}
116
117static int ma901radio_set_volume(struct ma901radio_device *radio, u16 vol_to_set)
118{
119	int retval;
120
121	radio->buffer[0] = 0x0a;
122	radio->buffer[1] = MA901_RADIO_SET_VOLUME;
123	radio->buffer[2] = 0xc2;
124	radio->buffer[3] = vol_to_set + 0x20;
125	radio->buffer[4] = 0x00;
126	radio->buffer[5] = 0x00;
127	radio->buffer[6] = 0x00;
128	radio->buffer[7] = 0x00;
129
130	retval = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
131				9, 0x21, 0x0300, 0,
132				radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
133	if (retval < 0)
134		return retval;
135
136	radio->volume = vol_to_set;
137	return retval;
138}
139
140static int ma901_set_stereo(struct ma901radio_device *radio, u8 stereo)
141{
142	int retval;
143
144	radio->buffer[0] = 0x0a;
145	radio->buffer[1] = MA901_RADIO_SET_MONO_STEREO;
146	radio->buffer[2] = stereo;
147	radio->buffer[3] = 0x00;
148	radio->buffer[4] = 0x00;
149	radio->buffer[5] = 0x00;
150	radio->buffer[6] = 0x00;
151	radio->buffer[7] = 0x00;
152
153	retval = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
154				9, 0x21, 0x0300, 0,
155				radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
156
157	if (retval < 0)
158		return retval;
159
160	if (stereo == MA901_WANT_STEREO)
161		radio->stereo = V4L2_TUNER_MODE_STEREO;
162	else
163		radio->stereo = V4L2_TUNER_MODE_MONO;
164
165	return retval;
166}
167
168/* Handle unplugging the device.
169 * We call video_unregister_device in any case.
170 * The last function called in this procedure is
171 * usb_ma901radio_device_release.
172 */
173static void usb_ma901radio_disconnect(struct usb_interface *intf)
174{
175	struct ma901radio_device *radio = to_ma901radio_dev(usb_get_intfdata(intf));
176
177	mutex_lock(&radio->lock);
178	video_unregister_device(&radio->vdev);
179	usb_set_intfdata(intf, NULL);
180	v4l2_device_disconnect(&radio->v4l2_dev);
181	mutex_unlock(&radio->lock);
182	v4l2_device_put(&radio->v4l2_dev);
183}
184
185/* vidioc_querycap - query device capabilities */
186static int vidioc_querycap(struct file *file, void *priv,
187					struct v4l2_capability *v)
188{
189	struct ma901radio_device *radio = video_drvdata(file);
190
191	strscpy(v->driver, "radio-ma901", sizeof(v->driver));
192	strscpy(v->card, "Masterkit MA901 USB FM Radio", sizeof(v->card));
193	usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
194	return 0;
195}
196
197/* vidioc_g_tuner - get tuner attributes */
198static int vidioc_g_tuner(struct file *file, void *priv,
199				struct v4l2_tuner *v)
200{
201	struct ma901radio_device *radio = video_drvdata(file);
202
203	if (v->index > 0)
204		return -EINVAL;
205
206	v->signal = 0;
207
208	/* TODO: the same words like in _probe() goes here.
209	 * When receiving of stats will be implemented then we can call
210	 * ma901radio_get_stat().
211	 * retval = ma901radio_get_stat(radio, &is_stereo, &v->signal);
212	 */
213
214	strscpy(v->name, "FM", sizeof(v->name));
215	v->type = V4L2_TUNER_RADIO;
216	v->rangelow = FREQ_MIN * FREQ_MUL;
217	v->rangehigh = FREQ_MAX * FREQ_MUL;
218	v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO;
219	/* v->rxsubchans = is_stereo ? V4L2_TUNER_SUB_STEREO : V4L2_TUNER_SUB_MONO; */
220	v->audmode = radio->stereo ?
221		V4L2_TUNER_MODE_STEREO : V4L2_TUNER_MODE_MONO;
222	return 0;
223}
224
225/* vidioc_s_tuner - set tuner attributes */
226static int vidioc_s_tuner(struct file *file, void *priv,
227				const struct v4l2_tuner *v)
228{
229	struct ma901radio_device *radio = video_drvdata(file);
230
231	if (v->index > 0)
232		return -EINVAL;
233
234	/* mono/stereo selector */
235	switch (v->audmode) {
236	case V4L2_TUNER_MODE_MONO:
237		return ma901_set_stereo(radio, MA901_WANT_MONO);
238	default:
239		return ma901_set_stereo(radio, MA901_WANT_STEREO);
240	}
241}
242
243/* vidioc_s_frequency - set tuner radio frequency */
244static int vidioc_s_frequency(struct file *file, void *priv,
245				const struct v4l2_frequency *f)
246{
247	struct ma901radio_device *radio = video_drvdata(file);
248
249	if (f->tuner != 0)
250		return -EINVAL;
251
252	return ma901radio_set_freq(radio, clamp_t(unsigned, f->frequency,
253				FREQ_MIN * FREQ_MUL, FREQ_MAX * FREQ_MUL));
254}
255
256/* vidioc_g_frequency - get tuner radio frequency */
257static int vidioc_g_frequency(struct file *file, void *priv,
258				struct v4l2_frequency *f)
259{
260	struct ma901radio_device *radio = video_drvdata(file);
261
262	if (f->tuner != 0)
263		return -EINVAL;
264	f->frequency = radio->curfreq;
265
266	return 0;
267}
268
269static int usb_ma901radio_s_ctrl(struct v4l2_ctrl *ctrl)
270{
271	struct ma901radio_device *radio =
272		container_of(ctrl->handler, struct ma901radio_device, hdl);
273
274	switch (ctrl->id) {
275	case V4L2_CID_AUDIO_VOLUME:     /* set volume */
276		return ma901radio_set_volume(radio, (u16)ctrl->val);
277	}
278
279	return -EINVAL;
280}
281
282/* TODO: Should we really need to implement suspend and resume functions?
283 * Radio has it's own memory and will continue playing if power is present
284 * on usb port and on resume it will start to play again based on freq, volume
285 * values in device memory.
286 */
287static int usb_ma901radio_suspend(struct usb_interface *intf, pm_message_t message)
288{
289	return 0;
290}
291
292static int usb_ma901radio_resume(struct usb_interface *intf)
293{
294	return 0;
295}
296
297static const struct v4l2_ctrl_ops usb_ma901radio_ctrl_ops = {
298	.s_ctrl = usb_ma901radio_s_ctrl,
299};
300
301/* File system interface */
302static const struct v4l2_file_operations usb_ma901radio_fops = {
303	.owner		= THIS_MODULE,
304	.open		= v4l2_fh_open,
305	.release	= v4l2_fh_release,
306	.poll		= v4l2_ctrl_poll,
307	.unlocked_ioctl	= video_ioctl2,
308};
309
310static const struct v4l2_ioctl_ops usb_ma901radio_ioctl_ops = {
311	.vidioc_querycap    = vidioc_querycap,
312	.vidioc_g_tuner     = vidioc_g_tuner,
313	.vidioc_s_tuner     = vidioc_s_tuner,
314	.vidioc_g_frequency = vidioc_g_frequency,
315	.vidioc_s_frequency = vidioc_s_frequency,
316	.vidioc_log_status  = v4l2_ctrl_log_status,
317	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
318	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
319};
320
321static void usb_ma901radio_release(struct v4l2_device *v4l2_dev)
322{
323	struct ma901radio_device *radio = to_ma901radio_dev(v4l2_dev);
324
325	v4l2_ctrl_handler_free(&radio->hdl);
326	v4l2_device_unregister(&radio->v4l2_dev);
327	kfree(radio->buffer);
328	kfree(radio);
329}
330
331/* check if the device is present and register with v4l and usb if it is */
332static int usb_ma901radio_probe(struct usb_interface *intf,
333				const struct usb_device_id *id)
334{
335	struct usb_device *dev = interface_to_usbdev(intf);
336	struct ma901radio_device *radio;
337	int retval = 0;
338
339	/* Masterkit MA901 usb radio has the same USB ID as many others
340	 * Atmel V-USB devices. Let's make additional checks to be sure
341	 * that this is our device.
342	 */
343
344	if (dev->product && dev->manufacturer &&
345		(strncmp(dev->product, "MA901", 5) != 0
346		|| strncmp(dev->manufacturer, "www.masterkit.ru", 16) != 0))
347		return -ENODEV;
348
349	radio = kzalloc(sizeof(struct ma901radio_device), GFP_KERNEL);
350	if (!radio) {
351		dev_err(&intf->dev, "kzalloc for ma901radio_device failed\n");
352		retval = -ENOMEM;
353		goto err;
354	}
355
356	radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);
357	if (!radio->buffer) {
358		dev_err(&intf->dev, "kmalloc for radio->buffer failed\n");
359		retval = -ENOMEM;
360		goto err_nobuf;
361	}
362
363	retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
364	if (retval < 0) {
365		dev_err(&intf->dev, "couldn't register v4l2_device\n");
366		goto err_v4l2;
367	}
368
369	v4l2_ctrl_handler_init(&radio->hdl, 1);
370
371	/* TODO:It looks like this radio doesn't have mute/unmute control
372	 * and windows program just emulate it using volume control.
373	 * Let's plan to do the same in this driver.
374	 *
375	 * v4l2_ctrl_new_std(&radio->hdl, &usb_ma901radio_ctrl_ops,
376	 *		  V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
377	 */
378
379	v4l2_ctrl_new_std(&radio->hdl, &usb_ma901radio_ctrl_ops,
380			  V4L2_CID_AUDIO_VOLUME, MA901_VOLUME_MIN,
381			  MA901_VOLUME_MAX, 1, MA901_VOLUME_MAX);
382
383	if (radio->hdl.error) {
384		retval = radio->hdl.error;
385		dev_err(&intf->dev, "couldn't register control\n");
386		goto err_ctrl;
387	}
388	mutex_init(&radio->lock);
389
390	radio->v4l2_dev.ctrl_handler = &radio->hdl;
391	radio->v4l2_dev.release = usb_ma901radio_release;
392	strscpy(radio->vdev.name, radio->v4l2_dev.name,
393		sizeof(radio->vdev.name));
394	radio->vdev.v4l2_dev = &radio->v4l2_dev;
395	radio->vdev.fops = &usb_ma901radio_fops;
396	radio->vdev.ioctl_ops = &usb_ma901radio_ioctl_ops;
397	radio->vdev.release = video_device_release_empty;
398	radio->vdev.lock = &radio->lock;
399	radio->vdev.device_caps = V4L2_CAP_RADIO | V4L2_CAP_TUNER;
400
401	radio->usbdev = interface_to_usbdev(intf);
402	radio->intf = intf;
403	usb_set_intfdata(intf, &radio->v4l2_dev);
404	radio->curfreq = 95.21 * FREQ_MUL;
405
406	video_set_drvdata(&radio->vdev, radio);
407
408	/* TODO: we can get some statistics (freq, volume) from device
409	 * but it's not implemented yet. After insertion in usb-port radio
410	 * setups frequency and starts playing without any initialization.
411	 * So we don't call usb_ma901radio_init/get_stat() here.
412	 * retval = usb_ma901radio_init(radio);
413	 */
414
415	retval = video_register_device(&radio->vdev, VFL_TYPE_RADIO,
416					radio_nr);
417	if (retval < 0) {
418		dev_err(&intf->dev, "could not register video device\n");
419		goto err_vdev;
420	}
421
422	return 0;
423
424err_vdev:
425	v4l2_ctrl_handler_free(&radio->hdl);
426err_ctrl:
427	v4l2_device_unregister(&radio->v4l2_dev);
428err_v4l2:
429	kfree(radio->buffer);
430err_nobuf:
431	kfree(radio);
432err:
433	return retval;
434}
435
436/* USB Device ID List */
437static const struct usb_device_id usb_ma901radio_device_table[] = {
438	{ USB_DEVICE_AND_INTERFACE_INFO(USB_MA901_VENDOR, USB_MA901_PRODUCT,
439							USB_CLASS_HID, 0, 0) },
440	{ }						/* Terminating entry */
441};
442
443MODULE_DEVICE_TABLE(usb, usb_ma901radio_device_table);
444
445/* USB subsystem interface */
446static struct usb_driver usb_ma901radio_driver = {
447	.name			= MA901_DRIVER_NAME,
448	.probe			= usb_ma901radio_probe,
449	.disconnect		= usb_ma901radio_disconnect,
450	.suspend		= usb_ma901radio_suspend,
451	.resume			= usb_ma901radio_resume,
452	.reset_resume		= usb_ma901radio_resume,
453	.id_table		= usb_ma901radio_device_table,
454};
455
456module_usb_driver(usb_ma901radio_driver);
457