xref: /openbmc/linux/drivers/media/rc/ir_toy.c (revision e15a5365)
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  * This driver is based on the lirc driver which can be found here:
9  * https://sourceforge.net/p/lirc/git/ci/master/tree/plugins/irtoy.c
10  * Copyright (C) 2011 Peter Kooiman <pkooiman@gmail.com>
11  */
12 
13 #include <asm/unaligned.h>
14 #include <linux/completion.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/usb.h>
18 #include <linux/slab.h>
19 #include <linux/usb/input.h>
20 
21 #include <media/rc-core.h>
22 
23 static const u8 COMMAND_VERSION[] = { 'v' };
24 // End transmit and repeat reset command so we exit sump mode
25 static const u8 COMMAND_RESET[] = { 0xff, 0xff, 0, 0, 0, 0, 0 };
26 static const u8 COMMAND_SMODE_ENTER[] = { 's' };
27 static const u8 COMMAND_TXSTART[] = { 0x26, 0x24, 0x25, 0x03 };
28 
29 #define REPLY_XMITCOUNT 't'
30 #define REPLY_XMITSUCCESS 'C'
31 #define REPLY_VERSION 'V'
32 #define REPLY_SAMPLEMODEPROTO 'S'
33 
34 #define TIMEOUT 500
35 
36 #define LEN_XMITRES 3
37 #define LEN_VERSION 4
38 #define LEN_SAMPLEMODEPROTO 3
39 
40 #define MIN_FW_VERSION 20
41 #define UNIT_US 21
42 #define MAX_TIMEOUT_US (UNIT_US * U16_MAX)
43 
44 #define MAX_PACKET 64
45 
46 enum state {
47 	STATE_IRDATA,
48 	STATE_RESET,
49 	STATE_COMMAND,
50 	STATE_TX,
51 };
52 
53 struct irtoy {
54 	struct device *dev;
55 	struct usb_device *usbdev;
56 
57 	struct rc_dev *rc;
58 	struct urb *urb_in, *urb_out;
59 
60 	u8 *in;
61 	u8 *out;
62 	struct completion command_done;
63 
64 	bool pulse;
65 	enum state state;
66 
67 	void *tx_buf;
68 	uint tx_len;
69 
70 	uint emitted;
71 	uint hw_version;
72 	uint sw_version;
73 	uint proto_version;
74 
75 	char phys[64];
76 };
77 
78 static void irtoy_response(struct irtoy *irtoy, u32 len)
79 {
80 	switch (irtoy->state) {
81 	case STATE_COMMAND:
82 		if (len == LEN_VERSION && irtoy->in[0] == REPLY_VERSION) {
83 			uint version;
84 
85 			irtoy->in[LEN_VERSION] = 0;
86 
87 			if (kstrtouint(irtoy->in + 1, 10, &version)) {
88 				dev_err(irtoy->dev, "invalid version %*phN. Please make sure you are using firmware v20 or higher",
89 					LEN_VERSION, irtoy->in);
90 				break;
91 			}
92 
93 			dev_dbg(irtoy->dev, "version %s\n", irtoy->in);
94 
95 			irtoy->hw_version = version / 100;
96 			irtoy->sw_version = version % 100;
97 
98 			irtoy->state = STATE_IRDATA;
99 			complete(&irtoy->command_done);
100 		} else if (len == LEN_SAMPLEMODEPROTO &&
101 			   irtoy->in[0] == REPLY_SAMPLEMODEPROTO) {
102 			uint version;
103 
104 			irtoy->in[LEN_SAMPLEMODEPROTO] = 0;
105 
106 			if (kstrtouint(irtoy->in + 1, 10, &version)) {
107 				dev_err(irtoy->dev, "invalid sample mode response %*phN",
108 					LEN_SAMPLEMODEPROTO, irtoy->in);
109 				return;
110 			}
111 
112 			dev_dbg(irtoy->dev, "protocol %s\n", irtoy->in);
113 
114 			irtoy->proto_version = version;
115 
116 			irtoy->state = STATE_IRDATA;
117 			complete(&irtoy->command_done);
118 		} else {
119 			dev_err(irtoy->dev, "unexpected response to command: %*phN\n",
120 				len, irtoy->in);
121 		}
122 		break;
123 	case STATE_IRDATA: {
124 		struct ir_raw_event rawir = { .pulse = irtoy->pulse };
125 		__be16 *in = (__be16 *)irtoy->in;
126 		int i;
127 
128 		for (i = 0; i < len / sizeof(__be16); i++) {
129 			u16 v = be16_to_cpu(in[i]);
130 
131 			if (v == 0xffff) {
132 				rawir.pulse = false;
133 			} else {
134 				rawir.duration = v * UNIT_US;
135 				ir_raw_event_store_with_timeout(irtoy->rc,
136 								&rawir);
137 			}
138 
139 			rawir.pulse = !rawir.pulse;
140 		}
141 
142 		irtoy->pulse = rawir.pulse;
143 
144 		ir_raw_event_handle(irtoy->rc);
145 		break;
146 	}
147 	case STATE_TX:
148 		if (irtoy->tx_len == 0) {
149 			if (len == LEN_XMITRES &&
150 			    irtoy->in[0] == REPLY_XMITCOUNT) {
151 				u16 emitted = get_unaligned_be16(irtoy->in + 1);
152 
153 				dev_dbg(irtoy->dev, "emitted:%u\n", emitted);
154 
155 				irtoy->emitted = emitted;
156 			} else if (len == 1 &&
157 				   irtoy->in[0] == REPLY_XMITSUCCESS) {
158 				irtoy->state = STATE_IRDATA;
159 				complete(&irtoy->command_done);
160 			}
161 		} else {
162 			// send next part of tx buffer
163 			uint space = irtoy->in[0];
164 			uint buf_len;
165 			int err;
166 
167 			if (len != 1 || space > MAX_PACKET || space == 0) {
168 				dev_err(irtoy->dev, "packet length expected: %*phN\n",
169 					len, irtoy->in);
170 				irtoy->state = STATE_IRDATA;
171 				complete(&irtoy->command_done);
172 				break;
173 			}
174 
175 			buf_len = min(space, irtoy->tx_len);
176 
177 			dev_dbg(irtoy->dev, "remaining:%u sending:%u\n",
178 				irtoy->tx_len, buf_len);
179 
180 			memcpy(irtoy->out, irtoy->tx_buf, buf_len);
181 			irtoy->urb_out->transfer_buffer_length = buf_len;
182 			err = usb_submit_urb(irtoy->urb_out, GFP_ATOMIC);
183 			if (err != 0) {
184 				dev_err(irtoy->dev, "fail to submit tx buf urb: %d\n",
185 					err);
186 				irtoy->state = STATE_IRDATA;
187 				complete(&irtoy->command_done);
188 				break;
189 			}
190 
191 			irtoy->tx_buf += buf_len;
192 			irtoy->tx_len -= buf_len;
193 		}
194 		break;
195 	case STATE_RESET:
196 		dev_err(irtoy->dev, "unexpected response to reset: %*phN\n",
197 			len, irtoy->in);
198 	}
199 }
200 
201 static void irtoy_out_callback(struct urb *urb)
202 {
203 	struct irtoy *irtoy = urb->context;
204 
205 	if (urb->status == 0) {
206 		if (irtoy->state == STATE_RESET)
207 			complete(&irtoy->command_done);
208 	} else {
209 		dev_warn(irtoy->dev, "out urb status: %d\n", urb->status);
210 	}
211 }
212 
213 static void irtoy_in_callback(struct urb *urb)
214 {
215 	struct irtoy *irtoy = urb->context;
216 	int ret;
217 
218 	if (urb->status == 0)
219 		irtoy_response(irtoy, urb->actual_length);
220 	else
221 		dev_dbg(irtoy->dev, "in urb status: %d\n", urb->status);
222 
223 	ret = usb_submit_urb(urb, GFP_ATOMIC);
224 	if (ret && ret != -ENODEV)
225 		dev_warn(irtoy->dev, "failed to resubmit urb: %d\n", ret);
226 }
227 
228 static int irtoy_command(struct irtoy *irtoy, const u8 *cmd, int cmd_len,
229 			 enum state state)
230 {
231 	int err;
232 
233 	init_completion(&irtoy->command_done);
234 
235 	irtoy->state = state;
236 
237 	memcpy(irtoy->out, cmd, cmd_len);
238 	irtoy->urb_out->transfer_buffer_length = cmd_len;
239 
240 	err = usb_submit_urb(irtoy->urb_out, GFP_KERNEL);
241 	if (err != 0)
242 		return err;
243 
244 	if (!wait_for_completion_timeout(&irtoy->command_done,
245 					 msecs_to_jiffies(TIMEOUT))) {
246 		usb_kill_urb(irtoy->urb_out);
247 		return -ETIMEDOUT;
248 	}
249 
250 	return 0;
251 }
252 
253 static int irtoy_setup(struct irtoy *irtoy)
254 {
255 	int err;
256 
257 	err = irtoy_command(irtoy, COMMAND_RESET, sizeof(COMMAND_RESET),
258 			    STATE_RESET);
259 	if (err != 0) {
260 		dev_err(irtoy->dev, "could not write reset command: %d\n",
261 			err);
262 		return err;
263 	}
264 
265 	usleep_range(50, 50);
266 
267 	// get version
268 	err = irtoy_command(irtoy, COMMAND_VERSION, sizeof(COMMAND_VERSION),
269 			    STATE_COMMAND);
270 	if (err) {
271 		dev_err(irtoy->dev, "could not write version command: %d\n",
272 			err);
273 		return err;
274 	}
275 
276 	// enter sample mode
277 	err = irtoy_command(irtoy, COMMAND_SMODE_ENTER,
278 			    sizeof(COMMAND_SMODE_ENTER), STATE_COMMAND);
279 	if (err)
280 		dev_err(irtoy->dev, "could not write sample command: %d\n",
281 			err);
282 
283 	return err;
284 }
285 
286 /*
287  * When sending IR, it is imperative that we send the IR data as quickly
288  * as possible to the device, so it does not run out of IR data and
289  * introduce gaps. Allocate the buffer here, and then feed the data from
290  * the urb callback handler.
291  */
292 static int irtoy_tx(struct rc_dev *rc, uint *txbuf, uint count)
293 {
294 	struct irtoy *irtoy = rc->priv;
295 	unsigned int i, size;
296 	__be16 *buf;
297 	int err;
298 
299 	size = sizeof(u16) * (count + 1);
300 	buf = kmalloc(size, GFP_KERNEL);
301 	if (!buf)
302 		return -ENOMEM;
303 
304 	for (i = 0; i < count; i++) {
305 		u16 v = DIV_ROUND_CLOSEST(txbuf[i], UNIT_US);
306 
307 		if (!v)
308 			v = 1;
309 		buf[i] = cpu_to_be16(v);
310 	}
311 
312 	buf[count] = cpu_to_be16(0xffff);
313 
314 	irtoy->tx_buf = buf;
315 	irtoy->tx_len = size;
316 	irtoy->emitted = 0;
317 
318 	err = irtoy_command(irtoy, COMMAND_TXSTART, sizeof(COMMAND_TXSTART),
319 			    STATE_TX);
320 	kfree(buf);
321 
322 	if (err) {
323 		dev_err(irtoy->dev, "failed to send tx start command: %d\n",
324 			err);
325 		// not sure what state the device is in, reset it
326 		irtoy_setup(irtoy);
327 		return err;
328 	}
329 
330 	if (size != irtoy->emitted) {
331 		dev_err(irtoy->dev, "expected %u emitted, got %u\n", size,
332 			irtoy->emitted);
333 		// not sure what state the device is in, reset it
334 		irtoy_setup(irtoy);
335 		return -EINVAL;
336 	}
337 
338 	return count;
339 }
340 
341 static int irtoy_probe(struct usb_interface *intf,
342 		       const struct usb_device_id *id)
343 {
344 	struct usb_host_interface *idesc = intf->cur_altsetting;
345 	struct usb_device *usbdev = interface_to_usbdev(intf);
346 	struct usb_endpoint_descriptor *ep_in = NULL;
347 	struct usb_endpoint_descriptor *ep_out = NULL;
348 	struct usb_endpoint_descriptor *ep = NULL;
349 	struct irtoy *irtoy;
350 	struct rc_dev *rc;
351 	struct urb *urb;
352 	int i, pipe, err = -ENOMEM;
353 
354 	for (i = 0; i < idesc->desc.bNumEndpoints; i++) {
355 		ep = &idesc->endpoint[i].desc;
356 
357 		if (!ep_in && usb_endpoint_is_bulk_in(ep) &&
358 		    usb_endpoint_maxp(ep) == MAX_PACKET)
359 			ep_in = ep;
360 
361 		if (!ep_out && usb_endpoint_is_bulk_out(ep) &&
362 		    usb_endpoint_maxp(ep) == MAX_PACKET)
363 			ep_out = ep;
364 	}
365 
366 	if (!ep_in || !ep_out) {
367 		dev_err(&intf->dev, "required endpoints not found\n");
368 		return -ENODEV;
369 	}
370 
371 	irtoy = kzalloc(sizeof(*irtoy), GFP_KERNEL);
372 	if (!irtoy)
373 		return -ENOMEM;
374 
375 	irtoy->in = kmalloc(MAX_PACKET,  GFP_KERNEL);
376 	if (!irtoy->in)
377 		goto free_irtoy;
378 
379 	irtoy->out = kmalloc(MAX_PACKET,  GFP_KERNEL);
380 	if (!irtoy->out)
381 		goto free_irtoy;
382 
383 	rc = rc_allocate_device(RC_DRIVER_IR_RAW);
384 	if (!rc)
385 		goto free_irtoy;
386 
387 	urb = usb_alloc_urb(0, GFP_KERNEL);
388 	if (!urb)
389 		goto free_rcdev;
390 
391 	pipe = usb_rcvbulkpipe(usbdev, ep_in->bEndpointAddress);
392 	usb_fill_bulk_urb(urb, usbdev, pipe, irtoy->in, MAX_PACKET,
393 			  irtoy_in_callback, irtoy);
394 	irtoy->urb_in = urb;
395 
396 	urb = usb_alloc_urb(0, GFP_KERNEL);
397 	if (!urb)
398 		goto free_rcdev;
399 
400 	pipe = usb_sndbulkpipe(usbdev, ep_out->bEndpointAddress);
401 	usb_fill_bulk_urb(urb, usbdev, pipe, irtoy->out, MAX_PACKET,
402 			  irtoy_out_callback, irtoy);
403 
404 	irtoy->dev = &intf->dev;
405 	irtoy->usbdev = usbdev;
406 	irtoy->rc = rc;
407 	irtoy->urb_out = urb;
408 	irtoy->pulse = true;
409 
410 	err = usb_submit_urb(irtoy->urb_in, GFP_KERNEL);
411 	if (err != 0) {
412 		dev_err(irtoy->dev, "fail to submit in urb: %d\n", err);
413 		return err;
414 	}
415 
416 	err = irtoy_setup(irtoy);
417 	if (err)
418 		goto free_rcdev;
419 
420 	dev_info(irtoy->dev, "version: hardware %u, firmware %u, protocol %u",
421 		 irtoy->hw_version, irtoy->sw_version, irtoy->proto_version);
422 
423 	if (irtoy->sw_version < MIN_FW_VERSION) {
424 		dev_err(irtoy->dev, "need firmware V%02u or higher",
425 			MIN_FW_VERSION);
426 		err = -ENODEV;
427 		goto free_rcdev;
428 	}
429 
430 	usb_make_path(usbdev, irtoy->phys, sizeof(irtoy->phys));
431 
432 	rc->device_name = "Infrared Toy";
433 	rc->driver_name = KBUILD_MODNAME;
434 	rc->input_phys = irtoy->phys;
435 	usb_to_input_id(usbdev, &rc->input_id);
436 	rc->dev.parent = &intf->dev;
437 	rc->priv = irtoy;
438 	rc->tx_ir = irtoy_tx;
439 	rc->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
440 	rc->map_name = RC_MAP_RC6_MCE;
441 	rc->rx_resolution = UNIT_US;
442 	rc->timeout = IR_DEFAULT_TIMEOUT;
443 
444 	/*
445 	 * end of transmission is detected by absence of a usb packet
446 	 * with more pulse/spaces. However, each usb packet sent can
447 	 * contain 32 pulse/spaces, which can be quite lengthy, so there
448 	 * can be a delay between usb packets. For example with nec there is a
449 	 * 17ms gap between packets.
450 	 *
451 	 * So, make timeout a largish minimum which works with most protocols.
452 	 */
453 	rc->min_timeout = MS_TO_US(40);
454 	rc->max_timeout = MAX_TIMEOUT_US;
455 
456 	err = rc_register_device(rc);
457 	if (err)
458 		goto free_rcdev;
459 
460 	usb_set_intfdata(intf, irtoy);
461 
462 	return 0;
463 
464 free_rcdev:
465 	usb_kill_urb(irtoy->urb_out);
466 	usb_free_urb(irtoy->urb_out);
467 	usb_kill_urb(irtoy->urb_in);
468 	usb_free_urb(irtoy->urb_in);
469 	rc_free_device(rc);
470 free_irtoy:
471 	kfree(irtoy->in);
472 	kfree(irtoy->out);
473 	kfree(irtoy);
474 	return err;
475 }
476 
477 static void irtoy_disconnect(struct usb_interface *intf)
478 {
479 	struct irtoy *ir = usb_get_intfdata(intf);
480 
481 	rc_unregister_device(ir->rc);
482 	usb_set_intfdata(intf, NULL);
483 	usb_kill_urb(ir->urb_out);
484 	usb_free_urb(ir->urb_out);
485 	usb_kill_urb(ir->urb_in);
486 	usb_free_urb(ir->urb_in);
487 	kfree(ir->in);
488 	kfree(ir->out);
489 	kfree(ir);
490 }
491 
492 static const struct usb_device_id irtoy_table[] = {
493 	{ USB_DEVICE_INTERFACE_CLASS(0x04d8, 0xfd08, USB_CLASS_CDC_DATA) },
494 	{ }
495 };
496 
497 static struct usb_driver irtoy_driver = {
498 	.name = KBUILD_MODNAME,
499 	.probe = irtoy_probe,
500 	.disconnect = irtoy_disconnect,
501 	.id_table = irtoy_table,
502 };
503 
504 module_usb_driver(irtoy_driver);
505 
506 MODULE_AUTHOR("Sean Young <sean@mess.org>");
507 MODULE_DESCRIPTION("Infrared Toy and IR Droid driver");
508 MODULE_LICENSE("GPL");
509 MODULE_DEVICE_TABLE(usb, irtoy_table);
510