1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2013 Cisco Systems, Inc. and/or its affiliates.
4 * All rights reserved.
5 */
6
7/* kernel includes */
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/usb.h>
11#include <linux/init.h>
12#include <linux/slab.h>
13#include <linux/input.h>
14#include <linux/mutex.h>
15#include <linux/i2c.h>
16/* V4l includes */
17#include <linux/videodev2.h>
18#include <media/v4l2-common.h>
19#include <media/v4l2-device.h>
20#include <media/v4l2-ioctl.h>
21#include <media/v4l2-event.h>
22#include <linux/platform_data/media/si4713.h>
23
24#include "si4713.h"
25
26/* driver and module definitions */
27MODULE_AUTHOR("Dinesh Ram <dinesh.ram@cern.ch>");
28MODULE_DESCRIPTION("Si4713 FM Transmitter USB driver");
29MODULE_LICENSE("GPL v2");
30
31/* The Device announces itself as Cygnal Integrated Products, Inc. */
32#define USB_SI4713_VENDOR		0x10c4
33#define USB_SI4713_PRODUCT		0x8244
34
35#define BUFFER_LENGTH			64
36#define USB_TIMEOUT			1000
37#define USB_RESP_TIMEOUT		50000
38
39/* USB Device ID List */
40static const struct usb_device_id usb_si4713_usb_device_table[] = {
41	{USB_DEVICE_AND_INTERFACE_INFO(USB_SI4713_VENDOR, USB_SI4713_PRODUCT,
42							USB_CLASS_HID, 0, 0) },
43	{ }						/* Terminating entry */
44};
45
46MODULE_DEVICE_TABLE(usb, usb_si4713_usb_device_table);
47
48struct si4713_usb_device {
49	struct usb_device	*usbdev;
50	struct usb_interface	*intf;
51	struct video_device	vdev;
52	struct v4l2_device	v4l2_dev;
53	struct v4l2_subdev	*v4l2_subdev;
54	struct mutex		lock;
55	struct i2c_adapter	i2c_adapter;
56
57	u8			*buffer;
58};
59
60static inline struct si4713_usb_device *to_si4713_dev(struct v4l2_device *v4l2_dev)
61{
62	return container_of(v4l2_dev, struct si4713_usb_device, v4l2_dev);
63}
64
65static int vidioc_querycap(struct file *file, void *priv,
66					struct v4l2_capability *v)
67{
68	struct si4713_usb_device *radio = video_drvdata(file);
69
70	strscpy(v->driver, "radio-usb-si4713", sizeof(v->driver));
71	strscpy(v->card, "Si4713 FM Transmitter", sizeof(v->card));
72	usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
73	return 0;
74}
75
76static int vidioc_g_modulator(struct file *file, void *priv,
77				struct v4l2_modulator *vm)
78{
79	struct si4713_usb_device *radio = video_drvdata(file);
80
81	return v4l2_subdev_call(radio->v4l2_subdev, tuner, g_modulator, vm);
82}
83
84static int vidioc_s_modulator(struct file *file, void *priv,
85				const struct v4l2_modulator *vm)
86{
87	struct si4713_usb_device *radio = video_drvdata(file);
88
89	return v4l2_subdev_call(radio->v4l2_subdev, tuner, s_modulator, vm);
90}
91
92static int vidioc_s_frequency(struct file *file, void *priv,
93				const struct v4l2_frequency *vf)
94{
95	struct si4713_usb_device *radio = video_drvdata(file);
96
97	return v4l2_subdev_call(radio->v4l2_subdev, tuner, s_frequency, vf);
98}
99
100static int vidioc_g_frequency(struct file *file, void *priv,
101				struct v4l2_frequency *vf)
102{
103	struct si4713_usb_device *radio = video_drvdata(file);
104
105	return v4l2_subdev_call(radio->v4l2_subdev, tuner, g_frequency, vf);
106}
107
108static const struct v4l2_ioctl_ops usb_si4713_ioctl_ops = {
109	.vidioc_querycap	  = vidioc_querycap,
110	.vidioc_g_modulator	  = vidioc_g_modulator,
111	.vidioc_s_modulator	  = vidioc_s_modulator,
112	.vidioc_g_frequency	  = vidioc_g_frequency,
113	.vidioc_s_frequency	  = vidioc_s_frequency,
114	.vidioc_log_status	  = v4l2_ctrl_log_status,
115	.vidioc_subscribe_event   = v4l2_ctrl_subscribe_event,
116	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
117};
118
119/* File system interface */
120static const struct v4l2_file_operations usb_si4713_fops = {
121	.owner		= THIS_MODULE,
122	.open           = v4l2_fh_open,
123	.release        = v4l2_fh_release,
124	.poll           = v4l2_ctrl_poll,
125	.unlocked_ioctl	= video_ioctl2,
126};
127
128static void usb_si4713_video_device_release(struct v4l2_device *v4l2_dev)
129{
130	struct si4713_usb_device *radio = to_si4713_dev(v4l2_dev);
131	struct i2c_adapter *adapter = &radio->i2c_adapter;
132
133	i2c_del_adapter(adapter);
134	v4l2_device_unregister(&radio->v4l2_dev);
135	kfree(radio->buffer);
136	kfree(radio);
137}
138
139/*
140 * This command sequence emulates the behaviour of the Windows driver.
141 * The structure of these commands was determined by sniffing the
142 * usb traffic of the device during startup.
143 * Most likely, these commands make some queries to the device.
144 * Commands are sent to enquire parameters like the bus mode,
145 * component revision, boot mode, the device serial number etc.
146 *
147 * These commands are necessary to be sent in this order during startup.
148 * The device fails to powerup if these commands are not sent.
149 *
150 * The complete list of startup commands is given in the start_seq table below.
151 */
152static int si4713_send_startup_command(struct si4713_usb_device *radio)
153{
154	unsigned long until_jiffies = jiffies + usecs_to_jiffies(USB_RESP_TIMEOUT) + 1;
155	u8 *buffer = radio->buffer;
156	int retval;
157
158	/* send the command */
159	retval = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
160					0x09, 0x21, 0x033f, 0, radio->buffer,
161					BUFFER_LENGTH, USB_TIMEOUT);
162	if (retval < 0)
163		return retval;
164
165	for (;;) {
166		/* receive the response */
167		retval = usb_control_msg(radio->usbdev, usb_rcvctrlpipe(radio->usbdev, 0),
168				0x01, 0xa1, 0x033f, 0, radio->buffer,
169				BUFFER_LENGTH, USB_TIMEOUT);
170		if (retval < 0)
171			return retval;
172		if (!radio->buffer[1]) {
173			/* USB traffic sniffing showed that some commands require
174			 * additional checks. */
175			switch (buffer[1]) {
176			case 0x32:
177				if (radio->buffer[2] == 0)
178					return 0;
179				break;
180			case 0x14:
181			case 0x12:
182				if (radio->buffer[2] & SI4713_CTS)
183					return 0;
184				break;
185			case 0x06:
186				if ((radio->buffer[2] & SI4713_CTS) && radio->buffer[9] == 0x08)
187					return 0;
188				break;
189			default:
190				return 0;
191			}
192		}
193		if (time_is_before_jiffies(until_jiffies))
194			return -EIO;
195		msleep(3);
196	}
197
198	return retval;
199}
200
201struct si4713_start_seq_table {
202	int len;
203	u8 payload[8];
204};
205
206/*
207 * Some of the startup commands that could be recognized are :
208 * (0x03): Get serial number of the board (Response : CB000-00-00)
209 * (0x06, 0x03, 0x03, 0x08, 0x01, 0x0f) : Get Component revision
210 */
211static const struct si4713_start_seq_table start_seq[] = {
212
213	{ 1, { 0x03 } },
214	{ 2, { 0x32, 0x7f } },
215	{ 6, { 0x06, 0x03, 0x03, 0x08, 0x01, 0x0f } },
216	{ 2, { 0x14, 0x02 } },
217	{ 2, { 0x09, 0x90 } },
218	{ 3, { 0x08, 0x90, 0xfa } },
219	{ 2, { 0x36, 0x01 } },
220	{ 2, { 0x05, 0x03 } },
221	{ 7, { 0x06, 0x00, 0x06, 0x0e, 0x01, 0x0f, 0x05 } },
222	{ 1, { 0x12 } },
223	/* Commands that are sent after pressing the 'Initialize'
224		button in the windows application */
225	{ 1, { 0x03 } },
226	{ 1, { 0x01 } },
227	{ 2, { 0x09, 0x90 } },
228	{ 3, { 0x08, 0x90, 0xfa } },
229	{ 1, { 0x34 } },
230	{ 2, { 0x35, 0x01 } },
231	{ 2, { 0x36, 0x01 } },
232	{ 2, { 0x30, 0x09 } },
233	{ 4, { 0x30, 0x06, 0x00, 0xe2 } },
234	{ 3, { 0x31, 0x01, 0x30 } },
235	{ 3, { 0x31, 0x04, 0x09 } },
236	{ 2, { 0x05, 0x02 } },
237	{ 6, { 0x06, 0x03, 0x03, 0x08, 0x01, 0x0f } },
238};
239
240static int si4713_start_seq(struct si4713_usb_device *radio)
241{
242	int retval = 0;
243	int i;
244
245	radio->buffer[0] = 0x3f;
246
247	for (i = 0; i < ARRAY_SIZE(start_seq); i++) {
248		int len = start_seq[i].len;
249		const u8 *payload = start_seq[i].payload;
250
251		memcpy(radio->buffer + 1, payload, len);
252		memset(radio->buffer + len + 1, 0, BUFFER_LENGTH - 1 - len);
253		retval = si4713_send_startup_command(radio);
254	}
255
256	return retval;
257}
258
259static struct i2c_board_info si4713_board_info = {
260	I2C_BOARD_INFO("si4713", SI4713_I2C_ADDR_BUSEN_HIGH),
261};
262
263struct si4713_command_table {
264	int command_id;
265	u8 payload[8];
266};
267
268/*
269 * Structure of a command :
270 *	Byte 1 : 0x3f (always)
271 *	Byte 2 : 0x06 (send a command)
272 *	Byte 3 : Unknown
273 *	Byte 4 : Number of arguments + 1 (for the command byte)
274 *	Byte 5 : Number of response bytes
275 */
276static struct si4713_command_table command_table[] = {
277
278	{ SI4713_CMD_POWER_UP,		{ 0x00, SI4713_PWUP_NARGS + 1, SI4713_PWUP_NRESP} },
279	{ SI4713_CMD_GET_REV,		{ 0x03, 0x01, SI4713_GETREV_NRESP } },
280	{ SI4713_CMD_POWER_DOWN,	{ 0x00, 0x01, SI4713_PWDN_NRESP} },
281	{ SI4713_CMD_SET_PROPERTY,	{ 0x00, SI4713_SET_PROP_NARGS + 1, SI4713_SET_PROP_NRESP } },
282	{ SI4713_CMD_GET_PROPERTY,	{ 0x00, SI4713_GET_PROP_NARGS + 1, SI4713_GET_PROP_NRESP } },
283	{ SI4713_CMD_TX_TUNE_FREQ,	{ 0x03, SI4713_TXFREQ_NARGS + 1, SI4713_TXFREQ_NRESP } },
284	{ SI4713_CMD_TX_TUNE_POWER,	{ 0x03, SI4713_TXPWR_NARGS + 1, SI4713_TXPWR_NRESP } },
285	{ SI4713_CMD_TX_TUNE_MEASURE,	{ 0x03, SI4713_TXMEA_NARGS + 1, SI4713_TXMEA_NRESP } },
286	{ SI4713_CMD_TX_TUNE_STATUS,	{ 0x00, SI4713_TXSTATUS_NARGS + 1, SI4713_TXSTATUS_NRESP } },
287	{ SI4713_CMD_TX_ASQ_STATUS,	{ 0x03, SI4713_ASQSTATUS_NARGS + 1, SI4713_ASQSTATUS_NRESP } },
288	{ SI4713_CMD_GET_INT_STATUS,	{ 0x03, 0x01, SI4713_GET_STATUS_NRESP } },
289	{ SI4713_CMD_TX_RDS_BUFF,	{ 0x03, SI4713_RDSBUFF_NARGS + 1, SI4713_RDSBUFF_NRESP } },
290	{ SI4713_CMD_TX_RDS_PS,		{ 0x00, SI4713_RDSPS_NARGS + 1, SI4713_RDSPS_NRESP } },
291};
292
293static int send_command(struct si4713_usb_device *radio, u8 *payload, char *data, int len)
294{
295	int retval;
296
297	radio->buffer[0] = 0x3f;
298	radio->buffer[1] = 0x06;
299
300	memcpy(radio->buffer + 2, payload, 3);
301	memcpy(radio->buffer + 5, data, len);
302	memset(radio->buffer + 5 + len, 0, BUFFER_LENGTH - 5 - len);
303
304	/* send the command */
305	retval = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
306					0x09, 0x21, 0x033f, 0, radio->buffer,
307					BUFFER_LENGTH, USB_TIMEOUT);
308
309	return retval < 0 ? retval : 0;
310}
311
312static int si4713_i2c_read(struct si4713_usb_device *radio, char *data, int len)
313{
314	unsigned long until_jiffies = jiffies + usecs_to_jiffies(USB_RESP_TIMEOUT) + 1;
315	int retval;
316
317	/* receive the response */
318	for (;;) {
319		retval = usb_control_msg(radio->usbdev,
320					usb_rcvctrlpipe(radio->usbdev, 0),
321					0x01, 0xa1, 0x033f, 0, radio->buffer,
322					BUFFER_LENGTH, USB_TIMEOUT);
323		if (retval < 0)
324			return retval;
325
326		/*
327		 * Check that we get a valid reply back (buffer[1] == 0) and
328		 * that CTS is set before returning, otherwise we wait and try
329		 * again. The i2c driver also does the CTS check, but the timeouts
330		 * used there are much too small for this USB driver, so we wait
331		 * for it here.
332		 */
333		if (radio->buffer[1] == 0 && (radio->buffer[2] & SI4713_CTS)) {
334			memcpy(data, radio->buffer + 2, len);
335			return 0;
336		}
337		if (time_is_before_jiffies(until_jiffies)) {
338			/* Zero the status value, ensuring CTS isn't set */
339			data[0] = 0;
340			return 0;
341		}
342		msleep(3);
343	}
344}
345
346static int si4713_i2c_write(struct si4713_usb_device *radio, char *data, int len)
347{
348	int retval = -EINVAL;
349	int i;
350
351	if (len > BUFFER_LENGTH - 5)
352		return -EINVAL;
353
354	for (i = 0; i < ARRAY_SIZE(command_table); i++) {
355		if (data[0] == command_table[i].command_id)
356			retval = send_command(radio, command_table[i].payload,
357						data, len);
358	}
359
360	return retval < 0 ? retval : 0;
361}
362
363static int si4713_transfer(struct i2c_adapter *i2c_adapter,
364				struct i2c_msg *msgs, int num)
365{
366	struct si4713_usb_device *radio = i2c_get_adapdata(i2c_adapter);
367	int retval = -EINVAL;
368	int i;
369
370	for (i = 0; i < num; i++) {
371		if (msgs[i].flags & I2C_M_RD)
372			retval = si4713_i2c_read(radio, msgs[i].buf, msgs[i].len);
373		else
374			retval = si4713_i2c_write(radio, msgs[i].buf, msgs[i].len);
375		if (retval)
376			break;
377	}
378
379	return retval ? retval : num;
380}
381
382static u32 si4713_functionality(struct i2c_adapter *adapter)
383{
384	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
385}
386
387static const struct i2c_algorithm si4713_algo = {
388	.master_xfer   = si4713_transfer,
389	.functionality = si4713_functionality,
390};
391
392/* This name value shows up in the sysfs filename associated
393		with this I2C adapter */
394static const struct i2c_adapter si4713_i2c_adapter_template = {
395	.name   = "si4713-i2c",
396	.owner  = THIS_MODULE,
397	.algo   = &si4713_algo,
398};
399
400static int si4713_register_i2c_adapter(struct si4713_usb_device *radio)
401{
402	radio->i2c_adapter = si4713_i2c_adapter_template;
403	/* set up sysfs linkage to our parent device */
404	radio->i2c_adapter.dev.parent = &radio->usbdev->dev;
405	i2c_set_adapdata(&radio->i2c_adapter, radio);
406
407	return i2c_add_adapter(&radio->i2c_adapter);
408}
409
410/* check if the device is present and register with v4l and usb if it is */
411static int usb_si4713_probe(struct usb_interface *intf,
412				const struct usb_device_id *id)
413{
414	struct si4713_usb_device *radio;
415	struct i2c_adapter *adapter;
416	struct v4l2_subdev *sd;
417	int retval;
418
419	dev_info(&intf->dev, "Si4713 development board discovered: (%04X:%04X)\n",
420			id->idVendor, id->idProduct);
421
422	/* Initialize local device structure */
423	radio = kzalloc(sizeof(struct si4713_usb_device), GFP_KERNEL);
424	if (radio)
425		radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);
426
427	if (!radio || !radio->buffer) {
428		dev_err(&intf->dev, "kmalloc for si4713_usb_device failed\n");
429		kfree(radio);
430		return -ENOMEM;
431	}
432
433	mutex_init(&radio->lock);
434
435	radio->usbdev = interface_to_usbdev(intf);
436	radio->intf = intf;
437	usb_set_intfdata(intf, &radio->v4l2_dev);
438
439	retval = si4713_start_seq(radio);
440	if (retval < 0)
441		goto err_v4l2;
442
443	retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
444	if (retval < 0) {
445		dev_err(&intf->dev, "couldn't register v4l2_device\n");
446		goto err_v4l2;
447	}
448
449	retval = si4713_register_i2c_adapter(radio);
450	if (retval < 0) {
451		dev_err(&intf->dev, "could not register i2c device\n");
452		goto err_i2cdev;
453	}
454
455	adapter = &radio->i2c_adapter;
456	sd = v4l2_i2c_new_subdev_board(&radio->v4l2_dev, adapter,
457					  &si4713_board_info, NULL);
458	radio->v4l2_subdev = sd;
459	if (!sd) {
460		dev_err(&intf->dev, "cannot get v4l2 subdevice\n");
461		retval = -ENODEV;
462		goto del_adapter;
463	}
464
465	radio->vdev.ctrl_handler = sd->ctrl_handler;
466	radio->v4l2_dev.release = usb_si4713_video_device_release;
467	strscpy(radio->vdev.name, radio->v4l2_dev.name,
468		sizeof(radio->vdev.name));
469	radio->vdev.v4l2_dev = &radio->v4l2_dev;
470	radio->vdev.fops = &usb_si4713_fops;
471	radio->vdev.ioctl_ops = &usb_si4713_ioctl_ops;
472	radio->vdev.lock = &radio->lock;
473	radio->vdev.release = video_device_release_empty;
474	radio->vdev.vfl_dir = VFL_DIR_TX;
475	radio->vdev.device_caps = V4L2_CAP_MODULATOR | V4L2_CAP_RDS_OUTPUT;
476
477	video_set_drvdata(&radio->vdev, radio);
478
479	retval = video_register_device(&radio->vdev, VFL_TYPE_RADIO, -1);
480	if (retval < 0) {
481		dev_err(&intf->dev, "could not register video device\n");
482		goto del_adapter;
483	}
484
485	dev_info(&intf->dev, "V4L2 device registered as %s\n",
486			video_device_node_name(&radio->vdev));
487
488	return 0;
489
490del_adapter:
491	i2c_del_adapter(adapter);
492err_i2cdev:
493	v4l2_device_unregister(&radio->v4l2_dev);
494err_v4l2:
495	kfree(radio->buffer);
496	kfree(radio);
497	return retval;
498}
499
500static void usb_si4713_disconnect(struct usb_interface *intf)
501{
502	struct si4713_usb_device *radio = to_si4713_dev(usb_get_intfdata(intf));
503
504	dev_info(&intf->dev, "Si4713 development board now disconnected\n");
505
506	mutex_lock(&radio->lock);
507	usb_set_intfdata(intf, NULL);
508	video_unregister_device(&radio->vdev);
509	v4l2_device_disconnect(&radio->v4l2_dev);
510	mutex_unlock(&radio->lock);
511	v4l2_device_put(&radio->v4l2_dev);
512}
513
514/* USB subsystem interface */
515static struct usb_driver usb_si4713_driver = {
516	.name			= "radio-usb-si4713",
517	.probe			= usb_si4713_probe,
518	.disconnect		= usb_si4713_disconnect,
519	.id_table		= usb_si4713_usb_device_table,
520};
521
522module_usb_driver(usb_si4713_driver);
523