1/*
2 * Driver for the MasterKit MA901 USB FM radio. This device plugs
3 * into the USB port and an analog audio input or headphones, so this thing
4 * only deals with initialization, frequency setting, volume.
5 *
6 * Copyright (c) 2012 Alexey Klimov <klimov.linux@gmail.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 */
22
23#include <linux/kernel.h>
24#include <linux/module.h>
25#include <linux/init.h>
26#include <linux/slab.h>
27#include <linux/input.h>
28#include <linux/videodev2.h>
29#include <media/v4l2-device.h>
30#include <media/v4l2-ioctl.h>
31#include <media/v4l2-ctrls.h>
32#include <media/v4l2-event.h>
33#include <linux/usb.h>
34#include <linux/mutex.h>
35
36#define DRIVER_AUTHOR "Alexey Klimov <klimov.linux@gmail.com>"
37#define DRIVER_DESC "Masterkit MA901 USB FM radio driver"
38#define DRIVER_VERSION "0.0.1"
39
40MODULE_AUTHOR(DRIVER_AUTHOR);
41MODULE_DESCRIPTION(DRIVER_DESC);
42MODULE_LICENSE("GPL");
43MODULE_VERSION(DRIVER_VERSION);
44
45#define USB_MA901_VENDOR  0x16c0
46#define USB_MA901_PRODUCT 0x05df
47
48/* dev_warn macro with driver name */
49#define MA901_DRIVER_NAME "radio-ma901"
50#define ma901radio_dev_warn(dev, fmt, arg...)				\
51		dev_warn(dev, MA901_DRIVER_NAME " - " fmt, ##arg)
52
53#define ma901radio_dev_err(dev, fmt, arg...) \
54		dev_err(dev, MA901_DRIVER_NAME " - " fmt, ##arg)
55
56/* Probably USB_TIMEOUT should be modified in module parameter */
57#define BUFFER_LENGTH 8
58#define USB_TIMEOUT 500
59
60#define FREQ_MIN  87.5
61#define FREQ_MAX 108.0
62#define FREQ_MUL 16000
63
64#define MA901_VOLUME_MAX 16
65#define MA901_VOLUME_MIN 0
66
67/* Commands that device should understand
68 * List isn't full and will be updated with implementation of new functions
69 */
70#define MA901_RADIO_SET_FREQ		0x03
71#define MA901_RADIO_SET_VOLUME		0x04
72#define MA901_RADIO_SET_MONO_STEREO	0x05
73
74/* Comfortable defines for ma901radio_set_stereo */
75#define MA901_WANT_STEREO		0x50
76#define MA901_WANT_MONO			0xd0
77
78/* module parameter */
79static int radio_nr = -1;
80module_param(radio_nr, int, 0);
81MODULE_PARM_DESC(radio_nr, "Radio file number");
82
83/* Data for one (physical) device */
84struct ma901radio_device {
85	/* reference to USB and video device */
86	struct usb_device *usbdev;
87	struct usb_interface *intf;
88	struct video_device vdev;
89	struct v4l2_device v4l2_dev;
90	struct v4l2_ctrl_handler hdl;
91
92	u8 *buffer;
93	struct mutex lock;	/* buffer locking */
94	int curfreq;
95	u16 volume;
96	int stereo;
97	bool muted;
98};
99
100static inline struct ma901radio_device *to_ma901radio_dev(struct v4l2_device *v4l2_dev)
101{
102	return container_of(v4l2_dev, struct ma901radio_device, v4l2_dev);
103}
104
105/* set a frequency, freq is defined by v4l's TUNER_LOW, i.e. 1/16th kHz */
106static int ma901radio_set_freq(struct ma901radio_device *radio, int freq)
107{
108	unsigned int freq_send = 0x300 + (freq >> 5) / 25;
109	int retval;
110
111	radio->buffer[0] = 0x0a;
112	radio->buffer[1] = MA901_RADIO_SET_FREQ;
113	radio->buffer[2] = ((freq_send >> 8) & 0xff) + 0x80;
114	radio->buffer[3] = freq_send & 0xff;
115	radio->buffer[4] = 0x00;
116	radio->buffer[5] = 0x00;
117	radio->buffer[6] = 0x00;
118	radio->buffer[7] = 0x00;
119
120	retval = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
121				9, 0x21, 0x0300, 0,
122				radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
123	if (retval < 0)
124		return retval;
125
126	radio->curfreq = freq;
127	return 0;
128}
129
130static int ma901radio_set_volume(struct ma901radio_device *radio, u16 vol_to_set)
131{
132	int retval;
133
134	radio->buffer[0] = 0x0a;
135	radio->buffer[1] = MA901_RADIO_SET_VOLUME;
136	radio->buffer[2] = 0xc2;
137	radio->buffer[3] = vol_to_set + 0x20;
138	radio->buffer[4] = 0x00;
139	radio->buffer[5] = 0x00;
140	radio->buffer[6] = 0x00;
141	radio->buffer[7] = 0x00;
142
143	retval = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
144				9, 0x21, 0x0300, 0,
145				radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
146	if (retval < 0)
147		return retval;
148
149	radio->volume = vol_to_set;
150	return retval;
151}
152
153static int ma901_set_stereo(struct ma901radio_device *radio, u8 stereo)
154{
155	int retval;
156
157	radio->buffer[0] = 0x0a;
158	radio->buffer[1] = MA901_RADIO_SET_MONO_STEREO;
159	radio->buffer[2] = stereo;
160	radio->buffer[3] = 0x00;
161	radio->buffer[4] = 0x00;
162	radio->buffer[5] = 0x00;
163	radio->buffer[6] = 0x00;
164	radio->buffer[7] = 0x00;
165
166	retval = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
167				9, 0x21, 0x0300, 0,
168				radio->buffer, BUFFER_LENGTH, USB_TIMEOUT);
169
170	if (retval < 0)
171		return retval;
172
173	if (stereo == MA901_WANT_STEREO)
174		radio->stereo = V4L2_TUNER_MODE_STEREO;
175	else
176		radio->stereo = V4L2_TUNER_MODE_MONO;
177
178	return retval;
179}
180
181/* Handle unplugging the device.
182 * We call video_unregister_device in any case.
183 * The last function called in this procedure is
184 * usb_ma901radio_device_release.
185 */
186static void usb_ma901radio_disconnect(struct usb_interface *intf)
187{
188	struct ma901radio_device *radio = to_ma901radio_dev(usb_get_intfdata(intf));
189
190	mutex_lock(&radio->lock);
191	video_unregister_device(&radio->vdev);
192	usb_set_intfdata(intf, NULL);
193	v4l2_device_disconnect(&radio->v4l2_dev);
194	mutex_unlock(&radio->lock);
195	v4l2_device_put(&radio->v4l2_dev);
196}
197
198/* vidioc_querycap - query device capabilities */
199static int vidioc_querycap(struct file *file, void *priv,
200					struct v4l2_capability *v)
201{
202	struct ma901radio_device *radio = video_drvdata(file);
203
204	strlcpy(v->driver, "radio-ma901", sizeof(v->driver));
205	strlcpy(v->card, "Masterkit MA901 USB FM Radio", sizeof(v->card));
206	usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
207	v->device_caps = V4L2_CAP_RADIO | V4L2_CAP_TUNER;
208	v->capabilities = v->device_caps | V4L2_CAP_DEVICE_CAPS;
209	return 0;
210}
211
212/* vidioc_g_tuner - get tuner attributes */
213static int vidioc_g_tuner(struct file *file, void *priv,
214				struct v4l2_tuner *v)
215{
216	struct ma901radio_device *radio = video_drvdata(file);
217
218	if (v->index > 0)
219		return -EINVAL;
220
221	v->signal = 0;
222
223	/* TODO: the same words like in _probe() goes here.
224	 * When receiving of stats will be implemented then we can call
225	 * ma901radio_get_stat().
226	 * retval = ma901radio_get_stat(radio, &is_stereo, &v->signal);
227	 */
228
229	strcpy(v->name, "FM");
230	v->type = V4L2_TUNER_RADIO;
231	v->rangelow = FREQ_MIN * FREQ_MUL;
232	v->rangehigh = FREQ_MAX * FREQ_MUL;
233	v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO;
234	/* v->rxsubchans = is_stereo ? V4L2_TUNER_SUB_STEREO : V4L2_TUNER_SUB_MONO; */
235	v->audmode = radio->stereo ?
236		V4L2_TUNER_MODE_STEREO : V4L2_TUNER_MODE_MONO;
237	return 0;
238}
239
240/* vidioc_s_tuner - set tuner attributes */
241static int vidioc_s_tuner(struct file *file, void *priv,
242				const struct v4l2_tuner *v)
243{
244	struct ma901radio_device *radio = video_drvdata(file);
245
246	if (v->index > 0)
247		return -EINVAL;
248
249	/* mono/stereo selector */
250	switch (v->audmode) {
251	case V4L2_TUNER_MODE_MONO:
252		return ma901_set_stereo(radio, MA901_WANT_MONO);
253	default:
254		return ma901_set_stereo(radio, MA901_WANT_STEREO);
255	}
256}
257
258/* vidioc_s_frequency - set tuner radio frequency */
259static int vidioc_s_frequency(struct file *file, void *priv,
260				const struct v4l2_frequency *f)
261{
262	struct ma901radio_device *radio = video_drvdata(file);
263
264	if (f->tuner != 0)
265		return -EINVAL;
266
267	return ma901radio_set_freq(radio, clamp_t(unsigned, f->frequency,
268				FREQ_MIN * FREQ_MUL, FREQ_MAX * FREQ_MUL));
269}
270
271/* vidioc_g_frequency - get tuner radio frequency */
272static int vidioc_g_frequency(struct file *file, void *priv,
273				struct v4l2_frequency *f)
274{
275	struct ma901radio_device *radio = video_drvdata(file);
276
277	if (f->tuner != 0)
278		return -EINVAL;
279	f->frequency = radio->curfreq;
280
281	return 0;
282}
283
284static int usb_ma901radio_s_ctrl(struct v4l2_ctrl *ctrl)
285{
286	struct ma901radio_device *radio =
287		container_of(ctrl->handler, struct ma901radio_device, hdl);
288
289	switch (ctrl->id) {
290	case V4L2_CID_AUDIO_VOLUME:     /* set volume */
291		return ma901radio_set_volume(radio, (u16)ctrl->val);
292	}
293
294	return -EINVAL;
295}
296
297/* TODO: Should we really need to implement suspend and resume functions?
298 * Radio has it's own memory and will continue playing if power is present
299 * on usb port and on resume it will start to play again based on freq, volume
300 * values in device memory.
301 */
302static int usb_ma901radio_suspend(struct usb_interface *intf, pm_message_t message)
303{
304	return 0;
305}
306
307static int usb_ma901radio_resume(struct usb_interface *intf)
308{
309	return 0;
310}
311
312static const struct v4l2_ctrl_ops usb_ma901radio_ctrl_ops = {
313	.s_ctrl = usb_ma901radio_s_ctrl,
314};
315
316/* File system interface */
317static const struct v4l2_file_operations usb_ma901radio_fops = {
318	.owner		= THIS_MODULE,
319	.open		= v4l2_fh_open,
320	.release	= v4l2_fh_release,
321	.poll		= v4l2_ctrl_poll,
322	.unlocked_ioctl	= video_ioctl2,
323};
324
325static const struct v4l2_ioctl_ops usb_ma901radio_ioctl_ops = {
326	.vidioc_querycap    = vidioc_querycap,
327	.vidioc_g_tuner     = vidioc_g_tuner,
328	.vidioc_s_tuner     = vidioc_s_tuner,
329	.vidioc_g_frequency = vidioc_g_frequency,
330	.vidioc_s_frequency = vidioc_s_frequency,
331	.vidioc_log_status  = v4l2_ctrl_log_status,
332	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
333	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
334};
335
336static void usb_ma901radio_release(struct v4l2_device *v4l2_dev)
337{
338	struct ma901radio_device *radio = to_ma901radio_dev(v4l2_dev);
339
340	v4l2_ctrl_handler_free(&radio->hdl);
341	v4l2_device_unregister(&radio->v4l2_dev);
342	kfree(radio->buffer);
343	kfree(radio);
344}
345
346/* check if the device is present and register with v4l and usb if it is */
347static int usb_ma901radio_probe(struct usb_interface *intf,
348				const struct usb_device_id *id)
349{
350	struct usb_device *dev = interface_to_usbdev(intf);
351	struct ma901radio_device *radio;
352	int retval = 0;
353
354	/* Masterkit MA901 usb radio has the same USB ID as many others
355	 * Atmel V-USB devices. Let's make additional checks to be sure
356	 * that this is our device.
357	 */
358
359	if (dev->product && dev->manufacturer &&
360		(strncmp(dev->product, "MA901", 5) != 0
361		|| strncmp(dev->manufacturer, "www.masterkit.ru", 16) != 0))
362		return -ENODEV;
363
364	radio = kzalloc(sizeof(struct ma901radio_device), GFP_KERNEL);
365	if (!radio) {
366		dev_err(&intf->dev, "kzalloc for ma901radio_device failed\n");
367		retval = -ENOMEM;
368		goto err;
369	}
370
371	radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);
372	if (!radio->buffer) {
373		dev_err(&intf->dev, "kmalloc for radio->buffer failed\n");
374		retval = -ENOMEM;
375		goto err_nobuf;
376	}
377
378	retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
379	if (retval < 0) {
380		dev_err(&intf->dev, "couldn't register v4l2_device\n");
381		goto err_v4l2;
382	}
383
384	v4l2_ctrl_handler_init(&radio->hdl, 1);
385
386	/* TODO:It looks like this radio doesn't have mute/unmute control
387	 * and windows program just emulate it using volume control.
388	 * Let's plan to do the same in this driver.
389	 *
390	 * v4l2_ctrl_new_std(&radio->hdl, &usb_ma901radio_ctrl_ops,
391	 *		  V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
392	 */
393
394	v4l2_ctrl_new_std(&radio->hdl, &usb_ma901radio_ctrl_ops,
395			  V4L2_CID_AUDIO_VOLUME, MA901_VOLUME_MIN,
396			  MA901_VOLUME_MAX, 1, MA901_VOLUME_MAX);
397
398	if (radio->hdl.error) {
399		retval = radio->hdl.error;
400		dev_err(&intf->dev, "couldn't register control\n");
401		goto err_ctrl;
402	}
403	mutex_init(&radio->lock);
404
405	radio->v4l2_dev.ctrl_handler = &radio->hdl;
406	radio->v4l2_dev.release = usb_ma901radio_release;
407	strlcpy(radio->vdev.name, radio->v4l2_dev.name,
408		sizeof(radio->vdev.name));
409	radio->vdev.v4l2_dev = &radio->v4l2_dev;
410	radio->vdev.fops = &usb_ma901radio_fops;
411	radio->vdev.ioctl_ops = &usb_ma901radio_ioctl_ops;
412	radio->vdev.release = video_device_release_empty;
413	radio->vdev.lock = &radio->lock;
414
415	radio->usbdev = interface_to_usbdev(intf);
416	radio->intf = intf;
417	usb_set_intfdata(intf, &radio->v4l2_dev);
418	radio->curfreq = 95.21 * FREQ_MUL;
419
420	video_set_drvdata(&radio->vdev, radio);
421
422	/* TODO: we can get some statistics (freq, volume) from device
423	 * but it's not implemented yet. After insertion in usb-port radio
424	 * setups frequency and starts playing without any initialization.
425	 * So we don't call usb_ma901radio_init/get_stat() here.
426	 * retval = usb_ma901radio_init(radio);
427	 */
428
429	retval = video_register_device(&radio->vdev, VFL_TYPE_RADIO,
430					radio_nr);
431	if (retval < 0) {
432		dev_err(&intf->dev, "could not register video device\n");
433		goto err_vdev;
434	}
435
436	return 0;
437
438err_vdev:
439	v4l2_ctrl_handler_free(&radio->hdl);
440err_ctrl:
441	v4l2_device_unregister(&radio->v4l2_dev);
442err_v4l2:
443	kfree(radio->buffer);
444err_nobuf:
445	kfree(radio);
446err:
447	return retval;
448}
449
450/* USB Device ID List */
451static struct usb_device_id usb_ma901radio_device_table[] = {
452	{ USB_DEVICE_AND_INTERFACE_INFO(USB_MA901_VENDOR, USB_MA901_PRODUCT,
453							USB_CLASS_HID, 0, 0) },
454	{ }						/* Terminating entry */
455};
456
457MODULE_DEVICE_TABLE(usb, usb_ma901radio_device_table);
458
459/* USB subsystem interface */
460static struct usb_driver usb_ma901radio_driver = {
461	.name			= MA901_DRIVER_NAME,
462	.probe			= usb_ma901radio_probe,
463	.disconnect		= usb_ma901radio_disconnect,
464	.suspend		= usb_ma901radio_suspend,
465	.resume			= usb_ma901radio_resume,
466	.reset_resume		= usb_ma901radio_resume,
467	.id_table		= usb_ma901radio_device_table,
468};
469
470module_usb_driver(usb_ma901radio_driver);
471