xref: /linux/drivers/media/radio/si4713/radio-usb-si4713.c (revision bfd5bb6f90af092aa345b15cd78143956a13c2a8)
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 */
27 MODULE_AUTHOR("Dinesh Ram <dinesh.ram@cern.ch>");
28 MODULE_DESCRIPTION("Si4713 FM Transmitter USB driver");
29 MODULE_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 */
40 static 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 
46 MODULE_DEVICE_TABLE(usb, usb_si4713_usb_device_table);
47 
48 struct 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 
60 static 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 
65 static 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 	strlcpy(v->driver, "radio-usb-si4713", sizeof(v->driver));
71 	strlcpy(v->card, "Si4713 FM Transmitter", sizeof(v->card));
72 	usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
73 	v->device_caps = V4L2_CAP_MODULATOR | V4L2_CAP_RDS_OUTPUT;
74 	v->capabilities = v->device_caps | V4L2_CAP_DEVICE_CAPS;
75 
76 	return 0;
77 }
78 
79 static int vidioc_g_modulator(struct file *file, void *priv,
80 				struct v4l2_modulator *vm)
81 {
82 	struct si4713_usb_device *radio = video_drvdata(file);
83 
84 	return v4l2_subdev_call(radio->v4l2_subdev, tuner, g_modulator, vm);
85 }
86 
87 static int vidioc_s_modulator(struct file *file, void *priv,
88 				const struct v4l2_modulator *vm)
89 {
90 	struct si4713_usb_device *radio = video_drvdata(file);
91 
92 	return v4l2_subdev_call(radio->v4l2_subdev, tuner, s_modulator, vm);
93 }
94 
95 static int vidioc_s_frequency(struct file *file, void *priv,
96 				const struct v4l2_frequency *vf)
97 {
98 	struct si4713_usb_device *radio = video_drvdata(file);
99 
100 	return v4l2_subdev_call(radio->v4l2_subdev, tuner, s_frequency, vf);
101 }
102 
103 static int vidioc_g_frequency(struct file *file, void *priv,
104 				struct v4l2_frequency *vf)
105 {
106 	struct si4713_usb_device *radio = video_drvdata(file);
107 
108 	return v4l2_subdev_call(radio->v4l2_subdev, tuner, g_frequency, vf);
109 }
110 
111 static const struct v4l2_ioctl_ops usb_si4713_ioctl_ops = {
112 	.vidioc_querycap	  = vidioc_querycap,
113 	.vidioc_g_modulator	  = vidioc_g_modulator,
114 	.vidioc_s_modulator	  = vidioc_s_modulator,
115 	.vidioc_g_frequency	  = vidioc_g_frequency,
116 	.vidioc_s_frequency	  = vidioc_s_frequency,
117 	.vidioc_log_status	  = v4l2_ctrl_log_status,
118 	.vidioc_subscribe_event   = v4l2_ctrl_subscribe_event,
119 	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
120 };
121 
122 /* File system interface */
123 static const struct v4l2_file_operations usb_si4713_fops = {
124 	.owner		= THIS_MODULE,
125 	.open           = v4l2_fh_open,
126 	.release        = v4l2_fh_release,
127 	.poll           = v4l2_ctrl_poll,
128 	.unlocked_ioctl	= video_ioctl2,
129 };
130 
131 static void usb_si4713_video_device_release(struct v4l2_device *v4l2_dev)
132 {
133 	struct si4713_usb_device *radio = to_si4713_dev(v4l2_dev);
134 	struct i2c_adapter *adapter = &radio->i2c_adapter;
135 
136 	i2c_del_adapter(adapter);
137 	v4l2_device_unregister(&radio->v4l2_dev);
138 	kfree(radio->buffer);
139 	kfree(radio);
140 }
141 
142 /*
143  * This command sequence emulates the behaviour of the Windows driver.
144  * The structure of these commands was determined by sniffing the
145  * usb traffic of the device during startup.
146  * Most likely, these commands make some queries to the device.
147  * Commands are sent to enquire parameters like the bus mode,
148  * component revision, boot mode, the device serial number etc.
149  *
150  * These commands are necessary to be sent in this order during startup.
151  * The device fails to powerup if these commands are not sent.
152  *
153  * The complete list of startup commands is given in the start_seq table below.
154  */
155 static int si4713_send_startup_command(struct si4713_usb_device *radio)
156 {
157 	unsigned long until_jiffies = jiffies + usecs_to_jiffies(USB_RESP_TIMEOUT) + 1;
158 	u8 *buffer = radio->buffer;
159 	int retval;
160 
161 	/* send the command */
162 	retval = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
163 					0x09, 0x21, 0x033f, 0, radio->buffer,
164 					BUFFER_LENGTH, USB_TIMEOUT);
165 	if (retval < 0)
166 		return retval;
167 
168 	for (;;) {
169 		/* receive the response */
170 		retval = usb_control_msg(radio->usbdev, usb_rcvctrlpipe(radio->usbdev, 0),
171 				0x01, 0xa1, 0x033f, 0, radio->buffer,
172 				BUFFER_LENGTH, USB_TIMEOUT);
173 		if (retval < 0)
174 			return retval;
175 		if (!radio->buffer[1]) {
176 			/* USB traffic sniffing showed that some commands require
177 			 * additional checks. */
178 			switch (buffer[1]) {
179 			case 0x32:
180 				if (radio->buffer[2] == 0)
181 					return 0;
182 				break;
183 			case 0x14:
184 			case 0x12:
185 				if (radio->buffer[2] & SI4713_CTS)
186 					return 0;
187 				break;
188 			case 0x06:
189 				if ((radio->buffer[2] & SI4713_CTS) && radio->buffer[9] == 0x08)
190 					return 0;
191 				break;
192 			default:
193 				return 0;
194 			}
195 		}
196 		if (time_is_before_jiffies(until_jiffies))
197 			return -EIO;
198 		msleep(3);
199 	}
200 
201 	return retval;
202 }
203 
204 struct si4713_start_seq_table {
205 	int len;
206 	u8 payload[8];
207 };
208 
209 /*
210  * Some of the startup commands that could be recognized are :
211  * (0x03): Get serial number of the board (Response : CB000-00-00)
212  * (0x06, 0x03, 0x03, 0x08, 0x01, 0x0f) : Get Component revision
213  */
214 static const struct si4713_start_seq_table start_seq[] = {
215 
216 	{ 1, { 0x03 } },
217 	{ 2, { 0x32, 0x7f } },
218 	{ 6, { 0x06, 0x03, 0x03, 0x08, 0x01, 0x0f } },
219 	{ 2, { 0x14, 0x02 } },
220 	{ 2, { 0x09, 0x90 } },
221 	{ 3, { 0x08, 0x90, 0xfa } },
222 	{ 2, { 0x36, 0x01 } },
223 	{ 2, { 0x05, 0x03 } },
224 	{ 7, { 0x06, 0x00, 0x06, 0x0e, 0x01, 0x0f, 0x05 } },
225 	{ 1, { 0x12 } },
226 	/* Commands that are sent after pressing the 'Initialize'
227 		button in the windows application */
228 	{ 1, { 0x03 } },
229 	{ 1, { 0x01 } },
230 	{ 2, { 0x09, 0x90 } },
231 	{ 3, { 0x08, 0x90, 0xfa } },
232 	{ 1, { 0x34 } },
233 	{ 2, { 0x35, 0x01 } },
234 	{ 2, { 0x36, 0x01 } },
235 	{ 2, { 0x30, 0x09 } },
236 	{ 4, { 0x30, 0x06, 0x00, 0xe2 } },
237 	{ 3, { 0x31, 0x01, 0x30 } },
238 	{ 3, { 0x31, 0x04, 0x09 } },
239 	{ 2, { 0x05, 0x02 } },
240 	{ 6, { 0x06, 0x03, 0x03, 0x08, 0x01, 0x0f } },
241 };
242 
243 static int si4713_start_seq(struct si4713_usb_device *radio)
244 {
245 	int retval = 0;
246 	int i;
247 
248 	radio->buffer[0] = 0x3f;
249 
250 	for (i = 0; i < ARRAY_SIZE(start_seq); i++) {
251 		int len = start_seq[i].len;
252 		const u8 *payload = start_seq[i].payload;
253 
254 		memcpy(radio->buffer + 1, payload, len);
255 		memset(radio->buffer + len + 1, 0, BUFFER_LENGTH - 1 - len);
256 		retval = si4713_send_startup_command(radio);
257 	}
258 
259 	return retval;
260 }
261 
262 static struct i2c_board_info si4713_board_info = {
263 	I2C_BOARD_INFO("si4713", SI4713_I2C_ADDR_BUSEN_HIGH),
264 };
265 
266 struct si4713_command_table {
267 	int command_id;
268 	u8 payload[8];
269 };
270 
271 /*
272  * Structure of a command :
273  *	Byte 1 : 0x3f (always)
274  *	Byte 2 : 0x06 (send a command)
275  *	Byte 3 : Unknown
276  *	Byte 4 : Number of arguments + 1 (for the command byte)
277  *	Byte 5 : Number of response bytes
278  */
279 static struct si4713_command_table command_table[] = {
280 
281 	{ SI4713_CMD_POWER_UP,		{ 0x00, SI4713_PWUP_NARGS + 1, SI4713_PWUP_NRESP} },
282 	{ SI4713_CMD_GET_REV,		{ 0x03, 0x01, SI4713_GETREV_NRESP } },
283 	{ SI4713_CMD_POWER_DOWN,	{ 0x00, 0x01, SI4713_PWDN_NRESP} },
284 	{ SI4713_CMD_SET_PROPERTY,	{ 0x00, SI4713_SET_PROP_NARGS + 1, SI4713_SET_PROP_NRESP } },
285 	{ SI4713_CMD_GET_PROPERTY,	{ 0x00, SI4713_GET_PROP_NARGS + 1, SI4713_GET_PROP_NRESP } },
286 	{ SI4713_CMD_TX_TUNE_FREQ,	{ 0x03, SI4713_TXFREQ_NARGS + 1, SI4713_TXFREQ_NRESP } },
287 	{ SI4713_CMD_TX_TUNE_POWER,	{ 0x03, SI4713_TXPWR_NARGS + 1, SI4713_TXPWR_NRESP } },
288 	{ SI4713_CMD_TX_TUNE_MEASURE,	{ 0x03, SI4713_TXMEA_NARGS + 1, SI4713_TXMEA_NRESP } },
289 	{ SI4713_CMD_TX_TUNE_STATUS,	{ 0x00, SI4713_TXSTATUS_NARGS + 1, SI4713_TXSTATUS_NRESP } },
290 	{ SI4713_CMD_TX_ASQ_STATUS,	{ 0x03, SI4713_ASQSTATUS_NARGS + 1, SI4713_ASQSTATUS_NRESP } },
291 	{ SI4713_CMD_GET_INT_STATUS,	{ 0x03, 0x01, SI4713_GET_STATUS_NRESP } },
292 	{ SI4713_CMD_TX_RDS_BUFF,	{ 0x03, SI4713_RDSBUFF_NARGS + 1, SI4713_RDSBUFF_NRESP } },
293 	{ SI4713_CMD_TX_RDS_PS,		{ 0x00, SI4713_RDSPS_NARGS + 1, SI4713_RDSPS_NRESP } },
294 };
295 
296 static int send_command(struct si4713_usb_device *radio, u8 *payload, char *data, int len)
297 {
298 	int retval;
299 
300 	radio->buffer[0] = 0x3f;
301 	radio->buffer[1] = 0x06;
302 
303 	memcpy(radio->buffer + 2, payload, 3);
304 	memcpy(radio->buffer + 5, data, len);
305 	memset(radio->buffer + 5 + len, 0, BUFFER_LENGTH - 5 - len);
306 
307 	/* send the command */
308 	retval = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
309 					0x09, 0x21, 0x033f, 0, radio->buffer,
310 					BUFFER_LENGTH, USB_TIMEOUT);
311 
312 	return retval < 0 ? retval : 0;
313 }
314 
315 static int si4713_i2c_read(struct si4713_usb_device *radio, char *data, int len)
316 {
317 	unsigned long until_jiffies = jiffies + usecs_to_jiffies(USB_RESP_TIMEOUT) + 1;
318 	int retval;
319 
320 	/* receive the response */
321 	for (;;) {
322 		retval = usb_control_msg(radio->usbdev,
323 					usb_rcvctrlpipe(radio->usbdev, 0),
324 					0x01, 0xa1, 0x033f, 0, radio->buffer,
325 					BUFFER_LENGTH, USB_TIMEOUT);
326 		if (retval < 0)
327 			return retval;
328 
329 		/*
330 		 * Check that we get a valid reply back (buffer[1] == 0) and
331 		 * that CTS is set before returning, otherwise we wait and try
332 		 * again. The i2c driver also does the CTS check, but the timeouts
333 		 * used there are much too small for this USB driver, so we wait
334 		 * for it here.
335 		 */
336 		if (radio->buffer[1] == 0 && (radio->buffer[2] & SI4713_CTS)) {
337 			memcpy(data, radio->buffer + 2, len);
338 			return 0;
339 		}
340 		if (time_is_before_jiffies(until_jiffies)) {
341 			/* Zero the status value, ensuring CTS isn't set */
342 			data[0] = 0;
343 			return 0;
344 		}
345 		msleep(3);
346 	}
347 }
348 
349 static int si4713_i2c_write(struct si4713_usb_device *radio, char *data, int len)
350 {
351 	int retval = -EINVAL;
352 	int i;
353 
354 	if (len > BUFFER_LENGTH - 5)
355 		return -EINVAL;
356 
357 	for (i = 0; i < ARRAY_SIZE(command_table); i++) {
358 		if (data[0] == command_table[i].command_id)
359 			retval = send_command(radio, command_table[i].payload,
360 						data, len);
361 	}
362 
363 	return retval < 0 ? retval : 0;
364 }
365 
366 static int si4713_transfer(struct i2c_adapter *i2c_adapter,
367 				struct i2c_msg *msgs, int num)
368 {
369 	struct si4713_usb_device *radio = i2c_get_adapdata(i2c_adapter);
370 	int retval = -EINVAL;
371 	int i;
372 
373 	if (num <= 0)
374 		return 0;
375 
376 	for (i = 0; i < num; i++) {
377 		if (msgs[i].flags & I2C_M_RD)
378 			retval = si4713_i2c_read(radio, msgs[i].buf, msgs[i].len);
379 		else
380 			retval = si4713_i2c_write(radio, msgs[i].buf, msgs[i].len);
381 		if (retval)
382 			break;
383 	}
384 
385 	return retval ? retval : num;
386 }
387 
388 static u32 si4713_functionality(struct i2c_adapter *adapter)
389 {
390 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
391 }
392 
393 static const struct i2c_algorithm si4713_algo = {
394 	.master_xfer   = si4713_transfer,
395 	.functionality = si4713_functionality,
396 };
397 
398 /* This name value shows up in the sysfs filename associated
399 		with this I2C adapter */
400 static const struct i2c_adapter si4713_i2c_adapter_template = {
401 	.name   = "si4713-i2c",
402 	.owner  = THIS_MODULE,
403 	.algo   = &si4713_algo,
404 };
405 
406 static int si4713_register_i2c_adapter(struct si4713_usb_device *radio)
407 {
408 	radio->i2c_adapter = si4713_i2c_adapter_template;
409 	/* set up sysfs linkage to our parent device */
410 	radio->i2c_adapter.dev.parent = &radio->usbdev->dev;
411 	i2c_set_adapdata(&radio->i2c_adapter, radio);
412 
413 	return i2c_add_adapter(&radio->i2c_adapter);
414 }
415 
416 /* check if the device is present and register with v4l and usb if it is */
417 static int usb_si4713_probe(struct usb_interface *intf,
418 				const struct usb_device_id *id)
419 {
420 	struct si4713_usb_device *radio;
421 	struct i2c_adapter *adapter;
422 	struct v4l2_subdev *sd;
423 	int retval = -ENOMEM;
424 
425 	dev_info(&intf->dev, "Si4713 development board discovered: (%04X:%04X)\n",
426 			id->idVendor, id->idProduct);
427 
428 	/* Initialize local device structure */
429 	radio = kzalloc(sizeof(struct si4713_usb_device), GFP_KERNEL);
430 	if (radio)
431 		radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);
432 
433 	if (!radio || !radio->buffer) {
434 		dev_err(&intf->dev, "kmalloc for si4713_usb_device failed\n");
435 		kfree(radio);
436 		return -ENOMEM;
437 	}
438 
439 	mutex_init(&radio->lock);
440 
441 	radio->usbdev = interface_to_usbdev(intf);
442 	radio->intf = intf;
443 	usb_set_intfdata(intf, &radio->v4l2_dev);
444 
445 	retval = si4713_start_seq(radio);
446 	if (retval < 0)
447 		goto err_v4l2;
448 
449 	retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
450 	if (retval < 0) {
451 		dev_err(&intf->dev, "couldn't register v4l2_device\n");
452 		goto err_v4l2;
453 	}
454 
455 	retval = si4713_register_i2c_adapter(radio);
456 	if (retval < 0) {
457 		dev_err(&intf->dev, "could not register i2c device\n");
458 		goto err_i2cdev;
459 	}
460 
461 	adapter = &radio->i2c_adapter;
462 	sd = v4l2_i2c_new_subdev_board(&radio->v4l2_dev, adapter,
463 					  &si4713_board_info, NULL);
464 	radio->v4l2_subdev = sd;
465 	if (!sd) {
466 		dev_err(&intf->dev, "cannot get v4l2 subdevice\n");
467 		retval = -ENODEV;
468 		goto del_adapter;
469 	}
470 
471 	radio->vdev.ctrl_handler = sd->ctrl_handler;
472 	radio->v4l2_dev.release = usb_si4713_video_device_release;
473 	strlcpy(radio->vdev.name, radio->v4l2_dev.name,
474 		sizeof(radio->vdev.name));
475 	radio->vdev.v4l2_dev = &radio->v4l2_dev;
476 	radio->vdev.fops = &usb_si4713_fops;
477 	radio->vdev.ioctl_ops = &usb_si4713_ioctl_ops;
478 	radio->vdev.lock = &radio->lock;
479 	radio->vdev.release = video_device_release_empty;
480 	radio->vdev.vfl_dir = VFL_DIR_TX;
481 
482 	video_set_drvdata(&radio->vdev, radio);
483 
484 	retval = video_register_device(&radio->vdev, VFL_TYPE_RADIO, -1);
485 	if (retval < 0) {
486 		dev_err(&intf->dev, "could not register video device\n");
487 		goto del_adapter;
488 	}
489 
490 	dev_info(&intf->dev, "V4L2 device registered as %s\n",
491 			video_device_node_name(&radio->vdev));
492 
493 	return 0;
494 
495 del_adapter:
496 	i2c_del_adapter(adapter);
497 err_i2cdev:
498 	v4l2_device_unregister(&radio->v4l2_dev);
499 err_v4l2:
500 	kfree(radio->buffer);
501 	kfree(radio);
502 	return retval;
503 }
504 
505 static void usb_si4713_disconnect(struct usb_interface *intf)
506 {
507 	struct si4713_usb_device *radio = to_si4713_dev(usb_get_intfdata(intf));
508 
509 	dev_info(&intf->dev, "Si4713 development board now disconnected\n");
510 
511 	mutex_lock(&radio->lock);
512 	usb_set_intfdata(intf, NULL);
513 	video_unregister_device(&radio->vdev);
514 	v4l2_device_disconnect(&radio->v4l2_dev);
515 	mutex_unlock(&radio->lock);
516 	v4l2_device_put(&radio->v4l2_dev);
517 }
518 
519 /* USB subsystem interface */
520 static struct usb_driver usb_si4713_driver = {
521 	.name			= "radio-usb-si4713",
522 	.probe			= usb_si4713_probe,
523 	.disconnect		= usb_si4713_disconnect,
524 	.id_table		= usb_si4713_usb_device_table,
525 };
526 
527 module_usb_driver(usb_si4713_driver);
528