xref: /linux/drivers/media/radio/si470x/radio-si470x-usb.c (revision 4949009eb8d40a441dcddcd96e101e77d31cf1b2)
1 /*
2  *  drivers/media/radio/si470x/radio-si470x-usb.c
3  *
4  *  USB driver for radios with Silicon Labs Si470x FM Radio Receivers
5  *
6  *  Copyright (c) 2009 Tobias Lorenz <tobias.lorenz@gmx.net>
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 
24 /*
25  * ToDo:
26  * - add firmware download/update support
27  */
28 
29 
30 /* driver definitions */
31 #define DRIVER_AUTHOR "Tobias Lorenz <tobias.lorenz@gmx.net>"
32 #define DRIVER_CARD "Silicon Labs Si470x FM Radio Receiver"
33 #define DRIVER_DESC "USB radio driver for Si470x FM Radio Receivers"
34 #define DRIVER_VERSION "1.0.10"
35 
36 /* kernel includes */
37 #include <linux/usb.h>
38 #include <linux/hid.h>
39 #include <linux/slab.h>
40 
41 #include "radio-si470x.h"
42 
43 
44 /* USB Device ID List */
45 static struct usb_device_id si470x_usb_driver_id_table[] = {
46 	/* Silicon Labs USB FM Radio Reference Design */
47 	{ USB_DEVICE_AND_INTERFACE_INFO(0x10c4, 0x818a, USB_CLASS_HID, 0, 0) },
48 	/* ADS/Tech FM Radio Receiver (formerly Instant FM Music) */
49 	{ USB_DEVICE_AND_INTERFACE_INFO(0x06e1, 0xa155, USB_CLASS_HID, 0, 0) },
50 	/* KWorld USB FM Radio SnapMusic Mobile 700 (FM700) */
51 	{ USB_DEVICE_AND_INTERFACE_INFO(0x1b80, 0xd700, USB_CLASS_HID, 0, 0) },
52 	/* Sanei Electric, Inc. FM USB Radio (sold as DealExtreme.com PCear) */
53 	{ USB_DEVICE_AND_INTERFACE_INFO(0x10c5, 0x819a, USB_CLASS_HID, 0, 0) },
54 	/* Axentia ALERT FM USB Receiver */
55 	{ USB_DEVICE_AND_INTERFACE_INFO(0x12cf, 0x7111, USB_CLASS_HID, 0, 0) },
56 	/* Terminating entry */
57 	{ }
58 };
59 MODULE_DEVICE_TABLE(usb, si470x_usb_driver_id_table);
60 
61 
62 
63 /**************************************************************************
64  * Module Parameters
65  **************************************************************************/
66 
67 /* Radio Nr */
68 static int radio_nr = -1;
69 module_param(radio_nr, int, 0444);
70 MODULE_PARM_DESC(radio_nr, "Radio Nr");
71 
72 /* USB timeout */
73 static unsigned int usb_timeout = 500;
74 module_param(usb_timeout, uint, 0644);
75 MODULE_PARM_DESC(usb_timeout, "USB timeout (ms): *500*");
76 
77 /* RDS buffer blocks */
78 static unsigned int rds_buf = 100;
79 module_param(rds_buf, uint, 0444);
80 MODULE_PARM_DESC(rds_buf, "RDS buffer entries: *100*");
81 
82 /* RDS maximum block errors */
83 static unsigned short max_rds_errors = 1;
84 /* 0 means   0  errors requiring correction */
85 /* 1 means 1-2  errors requiring correction (used by original USBRadio.exe) */
86 /* 2 means 3-5  errors requiring correction */
87 /* 3 means   6+ errors or errors in checkword, correction not possible */
88 module_param(max_rds_errors, ushort, 0644);
89 MODULE_PARM_DESC(max_rds_errors, "RDS maximum block errors: *1*");
90 
91 
92 
93 /**************************************************************************
94  * USB HID Reports
95  **************************************************************************/
96 
97 /* Reports 1-16 give direct read/write access to the 16 Si470x registers */
98 /* with the (REPORT_ID - 1) corresponding to the register address across USB */
99 /* endpoint 0 using GET_REPORT and SET_REPORT */
100 #define REGISTER_REPORT_SIZE	(RADIO_REGISTER_SIZE + 1)
101 #define REGISTER_REPORT(reg)	((reg) + 1)
102 
103 /* Report 17 gives direct read/write access to the entire Si470x register */
104 /* map across endpoint 0 using GET_REPORT and SET_REPORT */
105 #define ENTIRE_REPORT_SIZE	(RADIO_REGISTER_NUM * RADIO_REGISTER_SIZE + 1)
106 #define ENTIRE_REPORT		17
107 
108 /* Report 18 is used to send the lowest 6 Si470x registers up the HID */
109 /* interrupt endpoint 1 to Windows every 20 milliseconds for status */
110 #define RDS_REPORT_SIZE		(RDS_REGISTER_NUM * RADIO_REGISTER_SIZE + 1)
111 #define RDS_REPORT		18
112 
113 /* Report 19: LED state */
114 #define LED_REPORT_SIZE		3
115 #define LED_REPORT		19
116 
117 /* Report 19: stream */
118 #define STREAM_REPORT_SIZE	3
119 #define STREAM_REPORT		19
120 
121 /* Report 20: scratch */
122 #define SCRATCH_PAGE_SIZE	63
123 #define SCRATCH_REPORT_SIZE	(SCRATCH_PAGE_SIZE + 1)
124 #define SCRATCH_REPORT		20
125 
126 /* Reports 19-22: flash upgrade of the C8051F321 */
127 #define WRITE_REPORT_SIZE	4
128 #define WRITE_REPORT		19
129 #define FLASH_REPORT_SIZE	64
130 #define FLASH_REPORT		20
131 #define CRC_REPORT_SIZE		3
132 #define CRC_REPORT		21
133 #define RESPONSE_REPORT_SIZE	2
134 #define RESPONSE_REPORT		22
135 
136 /* Report 23: currently unused, but can accept 60 byte reports on the HID */
137 /* interrupt out endpoint 2 every 1 millisecond */
138 #define UNUSED_REPORT		23
139 
140 #define MAX_REPORT_SIZE		64
141 
142 
143 
144 /**************************************************************************
145  * Software/Hardware Versions from Scratch Page
146  **************************************************************************/
147 #define RADIO_HW_VERSION			1
148 
149 
150 
151 /**************************************************************************
152  * LED State Definitions
153  **************************************************************************/
154 #define LED_COMMAND		0x35
155 
156 #define NO_CHANGE_LED		0x00
157 #define ALL_COLOR_LED		0x01	/* streaming state */
158 #define BLINK_GREEN_LED		0x02	/* connect state */
159 #define BLINK_RED_LED		0x04
160 #define BLINK_ORANGE_LED	0x10	/* disconnect state */
161 #define SOLID_GREEN_LED		0x20	/* tuning/seeking state */
162 #define SOLID_RED_LED		0x40	/* bootload state */
163 #define SOLID_ORANGE_LED	0x80
164 
165 
166 
167 /**************************************************************************
168  * Stream State Definitions
169  **************************************************************************/
170 #define STREAM_COMMAND	0x36
171 #define STREAM_VIDPID	0x00
172 #define STREAM_AUDIO	0xff
173 
174 
175 
176 /**************************************************************************
177  * Bootloader / Flash Commands
178  **************************************************************************/
179 
180 /* unique id sent to bootloader and required to put into a bootload state */
181 #define UNIQUE_BL_ID		0x34
182 
183 /* mask for the flash data */
184 #define FLASH_DATA_MASK		0x55
185 
186 /* bootloader commands */
187 #define GET_SW_VERSION_COMMAND	0x00
188 #define SET_PAGE_COMMAND	0x01
189 #define ERASE_PAGE_COMMAND	0x02
190 #define WRITE_PAGE_COMMAND	0x03
191 #define CRC_ON_PAGE_COMMAND	0x04
192 #define READ_FLASH_BYTE_COMMAND	0x05
193 #define RESET_DEVICE_COMMAND	0x06
194 #define GET_HW_VERSION_COMMAND	0x07
195 #define BLANK			0xff
196 
197 /* bootloader command responses */
198 #define COMMAND_OK		0x01
199 #define COMMAND_FAILED		0x02
200 #define COMMAND_PENDING		0x03
201 
202 
203 
204 /**************************************************************************
205  * General Driver Functions - REGISTER_REPORTs
206  **************************************************************************/
207 
208 /*
209  * si470x_get_report - receive a HID report
210  */
211 static int si470x_get_report(struct si470x_device *radio, void *buf, int size)
212 {
213 	unsigned char *report = buf;
214 	int retval;
215 
216 	retval = usb_control_msg(radio->usbdev,
217 		usb_rcvctrlpipe(radio->usbdev, 0),
218 		HID_REQ_GET_REPORT,
219 		USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
220 		report[0], 2,
221 		buf, size, usb_timeout);
222 
223 	if (retval < 0)
224 		dev_warn(&radio->intf->dev,
225 			"si470x_get_report: usb_control_msg returned %d\n",
226 			retval);
227 	return retval;
228 }
229 
230 
231 /*
232  * si470x_set_report - send a HID report
233  */
234 static int si470x_set_report(struct si470x_device *radio, void *buf, int size)
235 {
236 	unsigned char *report = buf;
237 	int retval;
238 
239 	retval = usb_control_msg(radio->usbdev,
240 		usb_sndctrlpipe(radio->usbdev, 0),
241 		HID_REQ_SET_REPORT,
242 		USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
243 		report[0], 2,
244 		buf, size, usb_timeout);
245 
246 	if (retval < 0)
247 		dev_warn(&radio->intf->dev,
248 			"si470x_set_report: usb_control_msg returned %d\n",
249 			retval);
250 	return retval;
251 }
252 
253 
254 /*
255  * si470x_get_register - read register
256  */
257 int si470x_get_register(struct si470x_device *radio, int regnr)
258 {
259 	int retval;
260 
261 	radio->usb_buf[0] = REGISTER_REPORT(regnr);
262 
263 	retval = si470x_get_report(radio, radio->usb_buf, REGISTER_REPORT_SIZE);
264 
265 	if (retval >= 0)
266 		radio->registers[regnr] = get_unaligned_be16(&radio->usb_buf[1]);
267 
268 	return (retval < 0) ? -EINVAL : 0;
269 }
270 
271 
272 /*
273  * si470x_set_register - write register
274  */
275 int si470x_set_register(struct si470x_device *radio, int regnr)
276 {
277 	int retval;
278 
279 	radio->usb_buf[0] = REGISTER_REPORT(regnr);
280 	put_unaligned_be16(radio->registers[regnr], &radio->usb_buf[1]);
281 
282 	retval = si470x_set_report(radio, radio->usb_buf, REGISTER_REPORT_SIZE);
283 
284 	return (retval < 0) ? -EINVAL : 0;
285 }
286 
287 
288 
289 /**************************************************************************
290  * General Driver Functions - ENTIRE_REPORT
291  **************************************************************************/
292 
293 /*
294  * si470x_get_all_registers - read entire registers
295  */
296 static int si470x_get_all_registers(struct si470x_device *radio)
297 {
298 	int retval;
299 	unsigned char regnr;
300 
301 	radio->usb_buf[0] = ENTIRE_REPORT;
302 
303 	retval = si470x_get_report(radio, radio->usb_buf, ENTIRE_REPORT_SIZE);
304 
305 	if (retval >= 0)
306 		for (regnr = 0; regnr < RADIO_REGISTER_NUM; regnr++)
307 			radio->registers[regnr] = get_unaligned_be16(
308 				&radio->usb_buf[regnr * RADIO_REGISTER_SIZE + 1]);
309 
310 	return (retval < 0) ? -EINVAL : 0;
311 }
312 
313 
314 
315 /**************************************************************************
316  * General Driver Functions - LED_REPORT
317  **************************************************************************/
318 
319 /*
320  * si470x_set_led_state - sets the led state
321  */
322 static int si470x_set_led_state(struct si470x_device *radio,
323 		unsigned char led_state)
324 {
325 	int retval;
326 
327 	radio->usb_buf[0] = LED_REPORT;
328 	radio->usb_buf[1] = LED_COMMAND;
329 	radio->usb_buf[2] = led_state;
330 
331 	retval = si470x_set_report(radio, radio->usb_buf, LED_REPORT_SIZE);
332 
333 	return (retval < 0) ? -EINVAL : 0;
334 }
335 
336 
337 
338 /**************************************************************************
339  * General Driver Functions - SCRATCH_REPORT
340  **************************************************************************/
341 
342 /*
343  * si470x_get_scratch_versions - gets the scratch page and version infos
344  */
345 static int si470x_get_scratch_page_versions(struct si470x_device *radio)
346 {
347 	int retval;
348 
349 	radio->usb_buf[0] = SCRATCH_REPORT;
350 
351 	retval = si470x_get_report(radio, radio->usb_buf, SCRATCH_REPORT_SIZE);
352 
353 	if (retval < 0)
354 		dev_warn(&radio->intf->dev, "si470x_get_scratch: "
355 			"si470x_get_report returned %d\n", retval);
356 	else {
357 		radio->software_version = radio->usb_buf[1];
358 		radio->hardware_version = radio->usb_buf[2];
359 	}
360 
361 	return (retval < 0) ? -EINVAL : 0;
362 }
363 
364 
365 
366 /**************************************************************************
367  * RDS Driver Functions
368  **************************************************************************/
369 
370 /*
371  * si470x_int_in_callback - rds callback and processing function
372  *
373  * TODO: do we need to use mutex locks in some sections?
374  */
375 static void si470x_int_in_callback(struct urb *urb)
376 {
377 	struct si470x_device *radio = urb->context;
378 	int retval;
379 	unsigned char regnr;
380 	unsigned char blocknum;
381 	unsigned short bler; /* rds block errors */
382 	unsigned short rds;
383 	unsigned char tmpbuf[3];
384 
385 	if (urb->status) {
386 		if (urb->status == -ENOENT ||
387 				urb->status == -ECONNRESET ||
388 				urb->status == -ESHUTDOWN) {
389 			return;
390 		} else {
391 			dev_warn(&radio->intf->dev,
392 			 "non-zero urb status (%d)\n", urb->status);
393 			goto resubmit; /* Maybe we can recover. */
394 		}
395 	}
396 
397 	/* Sometimes the device returns len 0 packets */
398 	if (urb->actual_length != RDS_REPORT_SIZE)
399 		goto resubmit;
400 
401 	radio->registers[STATUSRSSI] =
402 		get_unaligned_be16(&radio->int_in_buffer[1]);
403 
404 	if (radio->registers[STATUSRSSI] & STATUSRSSI_STC)
405 		complete(&radio->completion);
406 
407 	if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS)) {
408 		/* Update RDS registers with URB data */
409 		for (regnr = 1; regnr < RDS_REGISTER_NUM; regnr++)
410 			radio->registers[STATUSRSSI + regnr] =
411 			    get_unaligned_be16(&radio->int_in_buffer[
412 				regnr * RADIO_REGISTER_SIZE + 1]);
413 		/* get rds blocks */
414 		if ((radio->registers[STATUSRSSI] & STATUSRSSI_RDSR) == 0) {
415 			/* No RDS group ready, better luck next time */
416 			goto resubmit;
417 		}
418 		if ((radio->registers[STATUSRSSI] & STATUSRSSI_RDSS) == 0) {
419 			/* RDS decoder not synchronized */
420 			goto resubmit;
421 		}
422 		for (blocknum = 0; blocknum < 4; blocknum++) {
423 			switch (blocknum) {
424 			default:
425 				bler = (radio->registers[STATUSRSSI] &
426 						STATUSRSSI_BLERA) >> 9;
427 				rds = radio->registers[RDSA];
428 				break;
429 			case 1:
430 				bler = (radio->registers[READCHAN] &
431 						READCHAN_BLERB) >> 14;
432 				rds = radio->registers[RDSB];
433 				break;
434 			case 2:
435 				bler = (radio->registers[READCHAN] &
436 						READCHAN_BLERC) >> 12;
437 				rds = radio->registers[RDSC];
438 				break;
439 			case 3:
440 				bler = (radio->registers[READCHAN] &
441 						READCHAN_BLERD) >> 10;
442 				rds = radio->registers[RDSD];
443 				break;
444 			}
445 
446 			/* Fill the V4L2 RDS buffer */
447 			put_unaligned_le16(rds, &tmpbuf);
448 			tmpbuf[2] = blocknum;		/* offset name */
449 			tmpbuf[2] |= blocknum << 3;	/* received offset */
450 			if (bler > max_rds_errors)
451 				tmpbuf[2] |= 0x80; /* uncorrectable errors */
452 			else if (bler > 0)
453 				tmpbuf[2] |= 0x40; /* corrected error(s) */
454 
455 			/* copy RDS block to internal buffer */
456 			memcpy(&radio->buffer[radio->wr_index], &tmpbuf, 3);
457 			radio->wr_index += 3;
458 
459 			/* wrap write pointer */
460 			if (radio->wr_index >= radio->buf_size)
461 				radio->wr_index = 0;
462 
463 			/* check for overflow */
464 			if (radio->wr_index == radio->rd_index) {
465 				/* increment and wrap read pointer */
466 				radio->rd_index += 3;
467 				if (radio->rd_index >= radio->buf_size)
468 					radio->rd_index = 0;
469 			}
470 		}
471 		if (radio->wr_index != radio->rd_index)
472 			wake_up_interruptible(&radio->read_queue);
473 	}
474 
475 resubmit:
476 	/* Resubmit if we're still running. */
477 	if (radio->int_in_running && radio->usbdev) {
478 		retval = usb_submit_urb(radio->int_in_urb, GFP_ATOMIC);
479 		if (retval) {
480 			dev_warn(&radio->intf->dev,
481 			       "resubmitting urb failed (%d)", retval);
482 			radio->int_in_running = 0;
483 		}
484 	}
485 	radio->status_rssi_auto_update = radio->int_in_running;
486 }
487 
488 
489 int si470x_fops_open(struct file *file)
490 {
491 	return v4l2_fh_open(file);
492 }
493 
494 int si470x_fops_release(struct file *file)
495 {
496 	return v4l2_fh_release(file);
497 }
498 
499 static void si470x_usb_release(struct v4l2_device *v4l2_dev)
500 {
501 	struct si470x_device *radio =
502 		container_of(v4l2_dev, struct si470x_device, v4l2_dev);
503 
504 	usb_free_urb(radio->int_in_urb);
505 	v4l2_ctrl_handler_free(&radio->hdl);
506 	v4l2_device_unregister(&radio->v4l2_dev);
507 	kfree(radio->int_in_buffer);
508 	kfree(radio->buffer);
509 	kfree(radio->usb_buf);
510 	kfree(radio);
511 }
512 
513 
514 /**************************************************************************
515  * Video4Linux Interface
516  **************************************************************************/
517 
518 /*
519  * si470x_vidioc_querycap - query device capabilities
520  */
521 int si470x_vidioc_querycap(struct file *file, void *priv,
522 		struct v4l2_capability *capability)
523 {
524 	struct si470x_device *radio = video_drvdata(file);
525 
526 	strlcpy(capability->driver, DRIVER_NAME, sizeof(capability->driver));
527 	strlcpy(capability->card, DRIVER_CARD, sizeof(capability->card));
528 	usb_make_path(radio->usbdev, capability->bus_info,
529 			sizeof(capability->bus_info));
530 	capability->device_caps = V4L2_CAP_HW_FREQ_SEEK | V4L2_CAP_READWRITE |
531 		V4L2_CAP_TUNER | V4L2_CAP_RADIO | V4L2_CAP_RDS_CAPTURE;
532 	capability->capabilities = capability->device_caps | V4L2_CAP_DEVICE_CAPS;
533 	return 0;
534 }
535 
536 
537 static int si470x_start_usb(struct si470x_device *radio)
538 {
539 	int retval;
540 
541 	/* initialize interrupt urb */
542 	usb_fill_int_urb(radio->int_in_urb, radio->usbdev,
543 			usb_rcvintpipe(radio->usbdev,
544 				radio->int_in_endpoint->bEndpointAddress),
545 			radio->int_in_buffer,
546 			le16_to_cpu(radio->int_in_endpoint->wMaxPacketSize),
547 			si470x_int_in_callback,
548 			radio,
549 			radio->int_in_endpoint->bInterval);
550 
551 	radio->int_in_running = 1;
552 	mb();
553 
554 	retval = usb_submit_urb(radio->int_in_urb, GFP_KERNEL);
555 	if (retval) {
556 		dev_info(&radio->intf->dev,
557 				"submitting int urb failed (%d)\n", retval);
558 		radio->int_in_running = 0;
559 	}
560 	radio->status_rssi_auto_update = radio->int_in_running;
561 
562 	/* start radio */
563 	retval = si470x_start(radio);
564 	if (retval < 0)
565 		return retval;
566 
567 	v4l2_ctrl_handler_setup(&radio->hdl);
568 
569 	return retval;
570 }
571 
572 /**************************************************************************
573  * USB Interface
574  **************************************************************************/
575 
576 /*
577  * si470x_usb_driver_probe - probe for the device
578  */
579 static int si470x_usb_driver_probe(struct usb_interface *intf,
580 		const struct usb_device_id *id)
581 {
582 	struct si470x_device *radio;
583 	struct usb_host_interface *iface_desc;
584 	struct usb_endpoint_descriptor *endpoint;
585 	int i, int_end_size, retval = 0;
586 	unsigned char version_warning = 0;
587 
588 	/* private data allocation and initialization */
589 	radio = kzalloc(sizeof(struct si470x_device), GFP_KERNEL);
590 	if (!radio) {
591 		retval = -ENOMEM;
592 		goto err_initial;
593 	}
594 	radio->usb_buf = kmalloc(MAX_REPORT_SIZE, GFP_KERNEL);
595 	if (radio->usb_buf == NULL) {
596 		retval = -ENOMEM;
597 		goto err_radio;
598 	}
599 	radio->usbdev = interface_to_usbdev(intf);
600 	radio->intf = intf;
601 	radio->band = 1; /* Default to 76 - 108 MHz */
602 	mutex_init(&radio->lock);
603 	init_completion(&radio->completion);
604 
605 	iface_desc = intf->cur_altsetting;
606 
607 	/* Set up interrupt endpoint information. */
608 	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
609 		endpoint = &iface_desc->endpoint[i].desc;
610 		if (usb_endpoint_is_int_in(endpoint))
611 			radio->int_in_endpoint = endpoint;
612 	}
613 	if (!radio->int_in_endpoint) {
614 		dev_info(&intf->dev, "could not find interrupt in endpoint\n");
615 		retval = -EIO;
616 		goto err_usbbuf;
617 	}
618 
619 	int_end_size = le16_to_cpu(radio->int_in_endpoint->wMaxPacketSize);
620 
621 	radio->int_in_buffer = kmalloc(int_end_size, GFP_KERNEL);
622 	if (!radio->int_in_buffer) {
623 		dev_info(&intf->dev, "could not allocate int_in_buffer");
624 		retval = -ENOMEM;
625 		goto err_usbbuf;
626 	}
627 
628 	radio->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
629 	if (!radio->int_in_urb) {
630 		dev_info(&intf->dev, "could not allocate int_in_urb");
631 		retval = -ENOMEM;
632 		goto err_intbuffer;
633 	}
634 
635 	radio->v4l2_dev.release = si470x_usb_release;
636 
637 	/*
638 	 * The si470x SiLabs reference design uses the same USB IDs as
639 	 * 'Thanko's Raremono' si4734 based receiver. So check here which we
640 	 * have: attempt to read the device ID from the si470x: the lower 12
641 	 * bits should be 0x0242 for the si470x.
642 	 *
643 	 * We use this check to determine which device we are dealing with.
644 	 */
645 	if (id->idVendor == 0x10c4 && id->idProduct == 0x818a) {
646 		retval = usb_control_msg(radio->usbdev,
647 				usb_rcvctrlpipe(radio->usbdev, 0),
648 				HID_REQ_GET_REPORT,
649 				USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
650 				1, 2,
651 				radio->usb_buf, 3, 500);
652 		if (retval != 3 ||
653 		    (get_unaligned_be16(&radio->usb_buf[1]) & 0xfff) != 0x0242) {
654 			dev_info(&intf->dev, "this is not a si470x device.\n");
655 			retval = -ENODEV;
656 			goto err_urb;
657 		}
658 	}
659 
660 	retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
661 	if (retval < 0) {
662 		dev_err(&intf->dev, "couldn't register v4l2_device\n");
663 		goto err_urb;
664 	}
665 
666 	v4l2_ctrl_handler_init(&radio->hdl, 2);
667 	v4l2_ctrl_new_std(&radio->hdl, &si470x_ctrl_ops,
668 			  V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
669 	v4l2_ctrl_new_std(&radio->hdl, &si470x_ctrl_ops,
670 			  V4L2_CID_AUDIO_VOLUME, 0, 15, 1, 15);
671 	if (radio->hdl.error) {
672 		retval = radio->hdl.error;
673 		dev_err(&intf->dev, "couldn't register control\n");
674 		goto err_dev;
675 	}
676 	radio->videodev = si470x_viddev_template;
677 	radio->videodev.ctrl_handler = &radio->hdl;
678 	radio->videodev.lock = &radio->lock;
679 	radio->videodev.v4l2_dev = &radio->v4l2_dev;
680 	radio->videodev.release = video_device_release_empty;
681 	video_set_drvdata(&radio->videodev, radio);
682 
683 	/* get device and chip versions */
684 	if (si470x_get_all_registers(radio) < 0) {
685 		retval = -EIO;
686 		goto err_ctrl;
687 	}
688 	dev_info(&intf->dev, "DeviceID=0x%4.4hx ChipID=0x%4.4hx\n",
689 			radio->registers[DEVICEID], radio->registers[CHIPID]);
690 	if ((radio->registers[CHIPID] & CHIPID_FIRMWARE) < RADIO_FW_VERSION) {
691 		dev_warn(&intf->dev,
692 			"This driver is known to work with "
693 			"firmware version %hu,\n", RADIO_FW_VERSION);
694 		dev_warn(&intf->dev,
695 			"but the device has firmware version %hu.\n",
696 			radio->registers[CHIPID] & CHIPID_FIRMWARE);
697 		version_warning = 1;
698 	}
699 
700 	/* get software and hardware versions */
701 	if (si470x_get_scratch_page_versions(radio) < 0) {
702 		retval = -EIO;
703 		goto err_ctrl;
704 	}
705 	dev_info(&intf->dev, "software version %d, hardware version %d\n",
706 			radio->software_version, radio->hardware_version);
707 	if (radio->hardware_version < RADIO_HW_VERSION) {
708 		dev_warn(&intf->dev,
709 			"This driver is known to work with "
710 			"hardware version %hu,\n", RADIO_HW_VERSION);
711 		dev_warn(&intf->dev,
712 			"but the device has hardware version %hu.\n",
713 			radio->hardware_version);
714 		version_warning = 1;
715 	}
716 
717 	/* give out version warning */
718 	if (version_warning == 1) {
719 		dev_warn(&intf->dev,
720 			"If you have some trouble using this driver,\n");
721 		dev_warn(&intf->dev,
722 			"please report to V4L ML at "
723 			"linux-media@vger.kernel.org\n");
724 	}
725 
726 	/* set led to connect state */
727 	si470x_set_led_state(radio, BLINK_GREEN_LED);
728 
729 	/* rds buffer allocation */
730 	radio->buf_size = rds_buf * 3;
731 	radio->buffer = kmalloc(radio->buf_size, GFP_KERNEL);
732 	if (!radio->buffer) {
733 		retval = -EIO;
734 		goto err_ctrl;
735 	}
736 
737 	/* rds buffer configuration */
738 	radio->wr_index = 0;
739 	radio->rd_index = 0;
740 	init_waitqueue_head(&radio->read_queue);
741 	usb_set_intfdata(intf, radio);
742 
743 	/* start radio */
744 	retval = si470x_start_usb(radio);
745 	if (retval < 0)
746 		goto err_all;
747 
748 	/* set initial frequency */
749 	si470x_set_freq(radio, 87.5 * FREQ_MUL); /* available in all regions */
750 
751 	/* register video device */
752 	retval = video_register_device(&radio->videodev, VFL_TYPE_RADIO,
753 			radio_nr);
754 	if (retval) {
755 		dev_err(&intf->dev, "Could not register video device\n");
756 		goto err_all;
757 	}
758 
759 	return 0;
760 err_all:
761 	kfree(radio->buffer);
762 err_ctrl:
763 	v4l2_ctrl_handler_free(&radio->hdl);
764 err_dev:
765 	v4l2_device_unregister(&radio->v4l2_dev);
766 err_urb:
767 	usb_free_urb(radio->int_in_urb);
768 err_intbuffer:
769 	kfree(radio->int_in_buffer);
770 err_usbbuf:
771 	kfree(radio->usb_buf);
772 err_radio:
773 	kfree(radio);
774 err_initial:
775 	return retval;
776 }
777 
778 
779 /*
780  * si470x_usb_driver_suspend - suspend the device
781  */
782 static int si470x_usb_driver_suspend(struct usb_interface *intf,
783 		pm_message_t message)
784 {
785 	struct si470x_device *radio = usb_get_intfdata(intf);
786 
787 	dev_info(&intf->dev, "suspending now...\n");
788 
789 	/* shutdown interrupt handler */
790 	if (radio->int_in_running) {
791 		radio->int_in_running = 0;
792 		if (radio->int_in_urb)
793 			usb_kill_urb(radio->int_in_urb);
794 	}
795 
796 	/* cancel read processes */
797 	wake_up_interruptible(&radio->read_queue);
798 
799 	/* stop radio */
800 	si470x_stop(radio);
801 	return 0;
802 }
803 
804 
805 /*
806  * si470x_usb_driver_resume - resume the device
807  */
808 static int si470x_usb_driver_resume(struct usb_interface *intf)
809 {
810 	struct si470x_device *radio = usb_get_intfdata(intf);
811 	int ret;
812 
813 	dev_info(&intf->dev, "resuming now...\n");
814 
815 	/* start radio */
816 	ret = si470x_start_usb(radio);
817 	if (ret == 0)
818 		v4l2_ctrl_handler_setup(&radio->hdl);
819 
820 	return ret;
821 }
822 
823 
824 /*
825  * si470x_usb_driver_disconnect - disconnect the device
826  */
827 static void si470x_usb_driver_disconnect(struct usb_interface *intf)
828 {
829 	struct si470x_device *radio = usb_get_intfdata(intf);
830 
831 	mutex_lock(&radio->lock);
832 	v4l2_device_disconnect(&radio->v4l2_dev);
833 	video_unregister_device(&radio->videodev);
834 	usb_set_intfdata(intf, NULL);
835 	mutex_unlock(&radio->lock);
836 	v4l2_device_put(&radio->v4l2_dev);
837 }
838 
839 
840 /*
841  * si470x_usb_driver - usb driver interface
842  *
843  * A note on suspend/resume: this driver had only empty suspend/resume
844  * functions, and when I tried to test suspend/resume it always disconnected
845  * instead of resuming (using my ADS InstantFM stick). So I've decided to
846  * remove these callbacks until someone else with better hardware can
847  * implement and test this.
848  */
849 static struct usb_driver si470x_usb_driver = {
850 	.name			= DRIVER_NAME,
851 	.probe			= si470x_usb_driver_probe,
852 	.disconnect		= si470x_usb_driver_disconnect,
853 	.suspend		= si470x_usb_driver_suspend,
854 	.resume			= si470x_usb_driver_resume,
855 	.reset_resume		= si470x_usb_driver_resume,
856 	.id_table		= si470x_usb_driver_id_table,
857 };
858 
859 module_usb_driver(si470x_usb_driver);
860 
861 MODULE_LICENSE("GPL");
862 MODULE_AUTHOR(DRIVER_AUTHOR);
863 MODULE_DESCRIPTION(DRIVER_DESC);
864 MODULE_VERSION(DRIVER_VERSION);
865