xref: /openbmc/linux/drivers/media/rc/ir_toy.c (revision 9a29f5fc)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 
3 /*
4  * Infrared Toy and IR Droid RC core driver
5  *
6  * Copyright (C) 2020 Sean Young <sean@mess.org>
7  *
8  * http://dangerousprototypes.com/docs/USB_IR_Toy:_Sampling_mode
9  *
10  * This driver is based on the lirc driver which can be found here:
11  * https://sourceforge.net/p/lirc/git/ci/master/tree/plugins/irtoy.c
12  * Copyright (C) 2011 Peter Kooiman <pkooiman@gmail.com>
13  */
14 
15 #include <asm/unaligned.h>
16 #include <linux/completion.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/usb.h>
20 #include <linux/slab.h>
21 #include <linux/usb/input.h>
22 
23 #include <media/rc-core.h>
24 
25 static const u8 COMMAND_VERSION[] = { 'v' };
26 // End transmit and repeat reset command so we exit sump mode
27 static const u8 COMMAND_RESET[] = { 0xff, 0xff, 0, 0, 0, 0, 0 };
28 static const u8 COMMAND_SMODE_ENTER[] = { 's' };
29 static const u8 COMMAND_SMODE_EXIT[] = { 0 };
30 static const u8 COMMAND_TXSTART[] = { 0x26, 0x24, 0x25, 0x03 };
31 
32 #define REPLY_XMITCOUNT 't'
33 #define REPLY_XMITSUCCESS 'C'
34 #define REPLY_VERSION 'V'
35 #define REPLY_SAMPLEMODEPROTO 'S'
36 
37 #define TIMEOUT 500
38 
39 #define LEN_XMITRES 3
40 #define LEN_VERSION 4
41 #define LEN_SAMPLEMODEPROTO 3
42 
43 #define MIN_FW_VERSION 20
44 #define UNIT_US 21
45 #define MAX_TIMEOUT_US (UNIT_US * U16_MAX)
46 
47 #define MAX_PACKET 64
48 
49 enum state {
50 	STATE_IRDATA,
51 	STATE_COMMAND_NO_RESP,
52 	STATE_COMMAND,
53 	STATE_TX,
54 };
55 
56 struct irtoy {
57 	struct device *dev;
58 	struct usb_device *usbdev;
59 
60 	struct rc_dev *rc;
61 	struct urb *urb_in, *urb_out;
62 
63 	u8 *in;
64 	u8 *out;
65 	struct completion command_done;
66 
67 	bool pulse;
68 	enum state state;
69 
70 	void *tx_buf;
71 	uint tx_len;
72 
73 	uint emitted;
74 	uint hw_version;
75 	uint sw_version;
76 	uint proto_version;
77 
78 	char phys[64];
79 };
80 
81 static void irtoy_response(struct irtoy *irtoy, u32 len)
82 {
83 	switch (irtoy->state) {
84 	case STATE_COMMAND:
85 		if (len == LEN_VERSION && irtoy->in[0] == REPLY_VERSION) {
86 			uint version;
87 
88 			irtoy->in[LEN_VERSION] = 0;
89 
90 			if (kstrtouint(irtoy->in + 1, 10, &version)) {
91 				dev_err(irtoy->dev, "invalid version %*phN. Please make sure you are using firmware v20 or higher",
92 					LEN_VERSION, irtoy->in);
93 				break;
94 			}
95 
96 			dev_dbg(irtoy->dev, "version %s\n", irtoy->in);
97 
98 			irtoy->hw_version = version / 100;
99 			irtoy->sw_version = version % 100;
100 
101 			irtoy->state = STATE_IRDATA;
102 			complete(&irtoy->command_done);
103 		} else if (len == LEN_SAMPLEMODEPROTO &&
104 			   irtoy->in[0] == REPLY_SAMPLEMODEPROTO) {
105 			uint version;
106 
107 			irtoy->in[LEN_SAMPLEMODEPROTO] = 0;
108 
109 			if (kstrtouint(irtoy->in + 1, 10, &version)) {
110 				dev_err(irtoy->dev, "invalid sample mode response %*phN",
111 					LEN_SAMPLEMODEPROTO, irtoy->in);
112 				return;
113 			}
114 
115 			dev_dbg(irtoy->dev, "protocol %s\n", irtoy->in);
116 
117 			irtoy->proto_version = version;
118 
119 			irtoy->state = STATE_IRDATA;
120 			complete(&irtoy->command_done);
121 		} else {
122 			dev_err(irtoy->dev, "unexpected response to command: %*phN\n",
123 				len, irtoy->in);
124 		}
125 		break;
126 	case STATE_COMMAND_NO_RESP:
127 	case STATE_IRDATA: {
128 		struct ir_raw_event rawir = { .pulse = irtoy->pulse };
129 		__be16 *in = (__be16 *)irtoy->in;
130 		int i;
131 
132 		for (i = 0; i < len / sizeof(__be16); i++) {
133 			u16 v = be16_to_cpu(in[i]);
134 
135 			if (v == 0xffff) {
136 				rawir.pulse = false;
137 			} else {
138 				rawir.duration = v * UNIT_US;
139 				ir_raw_event_store_with_timeout(irtoy->rc,
140 								&rawir);
141 			}
142 
143 			rawir.pulse = !rawir.pulse;
144 		}
145 
146 		irtoy->pulse = rawir.pulse;
147 
148 		ir_raw_event_handle(irtoy->rc);
149 		break;
150 	}
151 	case STATE_TX:
152 		if (irtoy->tx_len == 0) {
153 			if (len == LEN_XMITRES &&
154 			    irtoy->in[0] == REPLY_XMITCOUNT) {
155 				u16 emitted = get_unaligned_be16(irtoy->in + 1);
156 
157 				dev_dbg(irtoy->dev, "emitted:%u\n", emitted);
158 
159 				irtoy->emitted = emitted;
160 			} else if (len == 1 &&
161 				   irtoy->in[0] == REPLY_XMITSUCCESS) {
162 				irtoy->state = STATE_IRDATA;
163 				complete(&irtoy->command_done);
164 			}
165 		} else {
166 			// send next part of tx buffer
167 			uint space = irtoy->in[0];
168 			uint buf_len;
169 			int err;
170 
171 			if (len != 1 || space > MAX_PACKET || space == 0) {
172 				dev_dbg(irtoy->dev, "packet length expected: %*phN\n",
173 					len, irtoy->in);
174 				break;
175 			}
176 
177 			buf_len = min(space, irtoy->tx_len);
178 
179 			dev_dbg(irtoy->dev, "remaining:%u sending:%u\n",
180 				irtoy->tx_len, buf_len);
181 
182 			memcpy(irtoy->out, irtoy->tx_buf, buf_len);
183 			irtoy->urb_out->transfer_buffer_length = buf_len;
184 			err = usb_submit_urb(irtoy->urb_out, GFP_ATOMIC);
185 			if (err != 0) {
186 				dev_err(irtoy->dev, "fail to submit tx buf urb: %d\n",
187 					err);
188 				irtoy->state = STATE_IRDATA;
189 				complete(&irtoy->command_done);
190 				break;
191 			}
192 
193 			irtoy->tx_buf += buf_len;
194 			irtoy->tx_len -= buf_len;
195 		}
196 		break;
197 	}
198 }
199 
200 static void irtoy_out_callback(struct urb *urb)
201 {
202 	struct irtoy *irtoy = urb->context;
203 
204 	if (urb->status == 0) {
205 		if (irtoy->state == STATE_COMMAND_NO_RESP)
206 			complete(&irtoy->command_done);
207 	} else {
208 		dev_warn(irtoy->dev, "out urb status: %d\n", urb->status);
209 	}
210 }
211 
212 static void irtoy_in_callback(struct urb *urb)
213 {
214 	struct irtoy *irtoy = urb->context;
215 	int ret;
216 
217 	switch (urb->status) {
218 	case 0:
219 		irtoy_response(irtoy, urb->actual_length);
220 		break;
221 	case -ECONNRESET:
222 	case -ENOENT:
223 	case -ESHUTDOWN:
224 	case -EPROTO:
225 	case -EPIPE:
226 		usb_unlink_urb(urb);
227 		return;
228 	default:
229 		dev_dbg(irtoy->dev, "in urb status: %d\n", urb->status);
230 	}
231 
232 	ret = usb_submit_urb(urb, GFP_ATOMIC);
233 	if (ret && ret != -ENODEV)
234 		dev_warn(irtoy->dev, "failed to resubmit urb: %d\n", ret);
235 }
236 
237 static int irtoy_command(struct irtoy *irtoy, const u8 *cmd, int cmd_len,
238 			 enum state state)
239 {
240 	int err;
241 
242 	init_completion(&irtoy->command_done);
243 
244 	irtoy->state = state;
245 
246 	memcpy(irtoy->out, cmd, cmd_len);
247 	irtoy->urb_out->transfer_buffer_length = cmd_len;
248 
249 	err = usb_submit_urb(irtoy->urb_out, GFP_KERNEL);
250 	if (err != 0)
251 		return err;
252 
253 	if (!wait_for_completion_timeout(&irtoy->command_done,
254 					 msecs_to_jiffies(TIMEOUT))) {
255 		usb_kill_urb(irtoy->urb_out);
256 		return -ETIMEDOUT;
257 	}
258 
259 	return 0;
260 }
261 
262 static int irtoy_setup(struct irtoy *irtoy)
263 {
264 	int err;
265 
266 	err = irtoy_command(irtoy, COMMAND_RESET, sizeof(COMMAND_RESET),
267 			    STATE_COMMAND_NO_RESP);
268 	if (err != 0) {
269 		dev_err(irtoy->dev, "could not write reset command: %d\n",
270 			err);
271 		return err;
272 	}
273 
274 	usleep_range(50, 50);
275 
276 	// get version
277 	err = irtoy_command(irtoy, COMMAND_VERSION, sizeof(COMMAND_VERSION),
278 			    STATE_COMMAND);
279 	if (err) {
280 		dev_err(irtoy->dev, "could not write version command: %d\n",
281 			err);
282 		return err;
283 	}
284 
285 	// enter sample mode
286 	err = irtoy_command(irtoy, COMMAND_SMODE_ENTER,
287 			    sizeof(COMMAND_SMODE_ENTER), STATE_COMMAND);
288 	if (err)
289 		dev_err(irtoy->dev, "could not write sample command: %d\n",
290 			err);
291 
292 	return err;
293 }
294 
295 /*
296  * When sending IR, it is imperative that we send the IR data as quickly
297  * as possible to the device, so it does not run out of IR data and
298  * introduce gaps. Allocate the buffer here, and then feed the data from
299  * the urb callback handler.
300  */
301 static int irtoy_tx(struct rc_dev *rc, uint *txbuf, uint count)
302 {
303 	struct irtoy *irtoy = rc->priv;
304 	unsigned int i, size;
305 	__be16 *buf;
306 	int err;
307 
308 	size = sizeof(u16) * (count + 1);
309 	buf = kmalloc(size, GFP_KERNEL);
310 	if (!buf)
311 		return -ENOMEM;
312 
313 	for (i = 0; i < count; i++) {
314 		u16 v = DIV_ROUND_CLOSEST(txbuf[i], UNIT_US);
315 
316 		if (!v)
317 			v = 1;
318 		buf[i] = cpu_to_be16(v);
319 	}
320 
321 	buf[count] = cpu_to_be16(0xffff);
322 
323 	irtoy->tx_buf = buf;
324 	irtoy->tx_len = size;
325 	irtoy->emitted = 0;
326 
327 	// There is an issue where if the unit is receiving IR while the
328 	// first TXSTART command is sent, the device might end up hanging
329 	// with its led on. It does not respond to any command when this
330 	// happens. To work around this, re-enter sample mode.
331 	err = irtoy_command(irtoy, COMMAND_SMODE_EXIT,
332 			    sizeof(COMMAND_SMODE_EXIT), STATE_COMMAND_NO_RESP);
333 	if (err) {
334 		dev_err(irtoy->dev, "exit sample mode: %d\n", err);
335 		return err;
336 	}
337 
338 	err = irtoy_command(irtoy, COMMAND_SMODE_ENTER,
339 			    sizeof(COMMAND_SMODE_ENTER), STATE_COMMAND);
340 	if (err) {
341 		dev_err(irtoy->dev, "enter sample mode: %d\n", err);
342 		return err;
343 	}
344 
345 	err = irtoy_command(irtoy, COMMAND_TXSTART, sizeof(COMMAND_TXSTART),
346 			    STATE_TX);
347 	kfree(buf);
348 
349 	if (err) {
350 		dev_err(irtoy->dev, "failed to send tx start command: %d\n",
351 			err);
352 		// not sure what state the device is in, reset it
353 		irtoy_setup(irtoy);
354 		return err;
355 	}
356 
357 	if (size != irtoy->emitted) {
358 		dev_err(irtoy->dev, "expected %u emitted, got %u\n", size,
359 			irtoy->emitted);
360 		// not sure what state the device is in, reset it
361 		irtoy_setup(irtoy);
362 		return -EINVAL;
363 	}
364 
365 	return count;
366 }
367 
368 static int irtoy_tx_carrier(struct rc_dev *rc, uint32_t carrier)
369 {
370 	struct irtoy *irtoy = rc->priv;
371 	u8 buf[3];
372 	int err;
373 
374 	if (carrier < 11800)
375 		return -EINVAL;
376 
377 	buf[0] = 0x06;
378 	buf[1] = DIV_ROUND_CLOSEST(48000000, 16 * carrier) - 1;
379 	buf[2] = 0;
380 
381 	err = irtoy_command(irtoy, buf, sizeof(buf), STATE_COMMAND_NO_RESP);
382 	if (err)
383 		dev_err(irtoy->dev, "could not write carrier command: %d\n",
384 			err);
385 
386 	return err;
387 }
388 
389 static int irtoy_probe(struct usb_interface *intf,
390 		       const struct usb_device_id *id)
391 {
392 	struct usb_host_interface *idesc = intf->cur_altsetting;
393 	struct usb_device *usbdev = interface_to_usbdev(intf);
394 	struct usb_endpoint_descriptor *ep_in = NULL;
395 	struct usb_endpoint_descriptor *ep_out = NULL;
396 	struct usb_endpoint_descriptor *ep = NULL;
397 	struct irtoy *irtoy;
398 	struct rc_dev *rc;
399 	struct urb *urb;
400 	int i, pipe, err = -ENOMEM;
401 
402 	for (i = 0; i < idesc->desc.bNumEndpoints; i++) {
403 		ep = &idesc->endpoint[i].desc;
404 
405 		if (!ep_in && usb_endpoint_is_bulk_in(ep) &&
406 		    usb_endpoint_maxp(ep) == MAX_PACKET)
407 			ep_in = ep;
408 
409 		if (!ep_out && usb_endpoint_is_bulk_out(ep) &&
410 		    usb_endpoint_maxp(ep) == MAX_PACKET)
411 			ep_out = ep;
412 	}
413 
414 	if (!ep_in || !ep_out) {
415 		dev_err(&intf->dev, "required endpoints not found\n");
416 		return -ENODEV;
417 	}
418 
419 	irtoy = kzalloc(sizeof(*irtoy), GFP_KERNEL);
420 	if (!irtoy)
421 		return -ENOMEM;
422 
423 	irtoy->in = kmalloc(MAX_PACKET,  GFP_KERNEL);
424 	if (!irtoy->in)
425 		goto free_irtoy;
426 
427 	irtoy->out = kmalloc(MAX_PACKET,  GFP_KERNEL);
428 	if (!irtoy->out)
429 		goto free_irtoy;
430 
431 	rc = rc_allocate_device(RC_DRIVER_IR_RAW);
432 	if (!rc)
433 		goto free_irtoy;
434 
435 	urb = usb_alloc_urb(0, GFP_KERNEL);
436 	if (!urb)
437 		goto free_rcdev;
438 
439 	pipe = usb_rcvbulkpipe(usbdev, ep_in->bEndpointAddress);
440 	usb_fill_bulk_urb(urb, usbdev, pipe, irtoy->in, MAX_PACKET,
441 			  irtoy_in_callback, irtoy);
442 	irtoy->urb_in = urb;
443 
444 	urb = usb_alloc_urb(0, GFP_KERNEL);
445 	if (!urb)
446 		goto free_rcdev;
447 
448 	pipe = usb_sndbulkpipe(usbdev, ep_out->bEndpointAddress);
449 	usb_fill_bulk_urb(urb, usbdev, pipe, irtoy->out, MAX_PACKET,
450 			  irtoy_out_callback, irtoy);
451 
452 	irtoy->dev = &intf->dev;
453 	irtoy->usbdev = usbdev;
454 	irtoy->rc = rc;
455 	irtoy->urb_out = urb;
456 	irtoy->pulse = true;
457 
458 	err = usb_submit_urb(irtoy->urb_in, GFP_KERNEL);
459 	if (err != 0) {
460 		dev_err(irtoy->dev, "fail to submit in urb: %d\n", err);
461 		goto free_rcdev;
462 	}
463 
464 	err = irtoy_setup(irtoy);
465 	if (err)
466 		goto free_rcdev;
467 
468 	dev_info(irtoy->dev, "version: hardware %u, firmware %u.%u, protocol %u",
469 		 irtoy->hw_version, irtoy->sw_version / 10,
470 		 irtoy->sw_version % 10, irtoy->proto_version);
471 
472 	if (irtoy->sw_version < MIN_FW_VERSION) {
473 		dev_err(irtoy->dev, "need firmware V%02u or higher",
474 			MIN_FW_VERSION);
475 		err = -ENODEV;
476 		goto free_rcdev;
477 	}
478 
479 	usb_make_path(usbdev, irtoy->phys, sizeof(irtoy->phys));
480 
481 	rc->device_name = "Infrared Toy";
482 	rc->driver_name = KBUILD_MODNAME;
483 	rc->input_phys = irtoy->phys;
484 	usb_to_input_id(usbdev, &rc->input_id);
485 	rc->dev.parent = &intf->dev;
486 	rc->priv = irtoy;
487 	rc->tx_ir = irtoy_tx;
488 	rc->s_tx_carrier = irtoy_tx_carrier;
489 	rc->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
490 	rc->map_name = RC_MAP_RC6_MCE;
491 	rc->rx_resolution = UNIT_US;
492 	rc->timeout = IR_DEFAULT_TIMEOUT;
493 
494 	/*
495 	 * end of transmission is detected by absence of a usb packet
496 	 * with more pulse/spaces. However, each usb packet sent can
497 	 * contain 32 pulse/spaces, which can be quite lengthy, so there
498 	 * can be a delay between usb packets. For example with nec there is a
499 	 * 17ms gap between packets.
500 	 *
501 	 * So, make timeout a largish minimum which works with most protocols.
502 	 */
503 	rc->min_timeout = MS_TO_US(40);
504 	rc->max_timeout = MAX_TIMEOUT_US;
505 
506 	err = rc_register_device(rc);
507 	if (err)
508 		goto free_rcdev;
509 
510 	usb_set_intfdata(intf, irtoy);
511 
512 	return 0;
513 
514 free_rcdev:
515 	usb_kill_urb(irtoy->urb_out);
516 	usb_free_urb(irtoy->urb_out);
517 	usb_kill_urb(irtoy->urb_in);
518 	usb_free_urb(irtoy->urb_in);
519 	rc_free_device(rc);
520 free_irtoy:
521 	kfree(irtoy->in);
522 	kfree(irtoy->out);
523 	kfree(irtoy);
524 	return err;
525 }
526 
527 static void irtoy_disconnect(struct usb_interface *intf)
528 {
529 	struct irtoy *ir = usb_get_intfdata(intf);
530 
531 	rc_unregister_device(ir->rc);
532 	usb_set_intfdata(intf, NULL);
533 	usb_kill_urb(ir->urb_out);
534 	usb_free_urb(ir->urb_out);
535 	usb_kill_urb(ir->urb_in);
536 	usb_free_urb(ir->urb_in);
537 	kfree(ir->in);
538 	kfree(ir->out);
539 	kfree(ir);
540 }
541 
542 static const struct usb_device_id irtoy_table[] = {
543 	{ USB_DEVICE_INTERFACE_CLASS(0x04d8, 0xfd08, USB_CLASS_CDC_DATA) },
544 	{ USB_DEVICE_INTERFACE_CLASS(0x04d8, 0xf58b, USB_CLASS_CDC_DATA) },
545 	{ }
546 };
547 
548 static struct usb_driver irtoy_driver = {
549 	.name = KBUILD_MODNAME,
550 	.probe = irtoy_probe,
551 	.disconnect = irtoy_disconnect,
552 	.id_table = irtoy_table,
553 };
554 
555 module_usb_driver(irtoy_driver);
556 
557 MODULE_AUTHOR("Sean Young <sean@mess.org>");
558 MODULE_DESCRIPTION("Infrared Toy and IR Droid driver");
559 MODULE_LICENSE("GPL");
560 MODULE_DEVICE_TABLE(usb, irtoy_table);
561