1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * IguanaWorks USB IR Transceiver support
4 *
5 * Copyright (C) 2012 Sean Young <sean@mess.org>
6 */
7
8#include <linux/device.h>
9#include <linux/kernel.h>
10#include <linux/module.h>
11#include <linux/usb.h>
12#include <linux/usb/input.h>
13#include <linux/slab.h>
14#include <linux/completion.h>
15#include <media/rc-core.h>
16
17#define BUF_SIZE 152
18
19struct iguanair {
20	struct rc_dev *rc;
21
22	struct device *dev;
23	struct usb_device *udev;
24
25	uint16_t version;
26	uint8_t bufsize;
27	uint8_t cycle_overhead;
28
29	/* receiver support */
30	bool receiver_on;
31	dma_addr_t dma_in, dma_out;
32	uint8_t *buf_in;
33	struct urb *urb_in, *urb_out;
34	struct completion completion;
35
36	/* transmit support */
37	bool tx_overflow;
38	uint32_t carrier;
39	struct send_packet *packet;
40
41	char name[64];
42	char phys[64];
43};
44
45#define CMD_NOP			0x00
46#define CMD_GET_VERSION		0x01
47#define CMD_GET_BUFSIZE		0x11
48#define CMD_GET_FEATURES	0x10
49#define CMD_SEND		0x15
50#define CMD_EXECUTE		0x1f
51#define CMD_RX_OVERFLOW		0x31
52#define CMD_TX_OVERFLOW		0x32
53#define CMD_RECEIVER_ON		0x12
54#define CMD_RECEIVER_OFF	0x14
55
56#define DIR_IN			0xdc
57#define DIR_OUT			0xcd
58
59#define MAX_IN_PACKET		8u
60#define MAX_OUT_PACKET		(sizeof(struct send_packet) + BUF_SIZE)
61#define TIMEOUT			1000
62#define RX_RESOLUTION		21
63
64struct packet {
65	uint16_t start;
66	uint8_t direction;
67	uint8_t cmd;
68};
69
70struct send_packet {
71	struct packet header;
72	uint8_t length;
73	uint8_t channels;
74	uint8_t busy7;
75	uint8_t busy4;
76	uint8_t payload[];
77};
78
79static void process_ir_data(struct iguanair *ir, unsigned len)
80{
81	if (len >= 4 && ir->buf_in[0] == 0 && ir->buf_in[1] == 0) {
82		switch (ir->buf_in[3]) {
83		case CMD_GET_VERSION:
84			if (len == 6) {
85				ir->version = (ir->buf_in[5] << 8) |
86							ir->buf_in[4];
87				complete(&ir->completion);
88			}
89			break;
90		case CMD_GET_BUFSIZE:
91			if (len >= 5) {
92				ir->bufsize = ir->buf_in[4];
93				complete(&ir->completion);
94			}
95			break;
96		case CMD_GET_FEATURES:
97			if (len > 5) {
98				ir->cycle_overhead = ir->buf_in[5];
99				complete(&ir->completion);
100			}
101			break;
102		case CMD_TX_OVERFLOW:
103			ir->tx_overflow = true;
104			fallthrough;
105		case CMD_RECEIVER_OFF:
106		case CMD_RECEIVER_ON:
107		case CMD_SEND:
108			complete(&ir->completion);
109			break;
110		case CMD_RX_OVERFLOW:
111			dev_warn(ir->dev, "receive overflow\n");
112			ir_raw_event_reset(ir->rc);
113			break;
114		default:
115			dev_warn(ir->dev, "control code %02x received\n",
116							ir->buf_in[3]);
117			break;
118		}
119	} else if (len >= 7) {
120		struct ir_raw_event rawir = {};
121		unsigned i;
122		bool event = false;
123
124		for (i = 0; i < 7; i++) {
125			if (ir->buf_in[i] == 0x80) {
126				rawir.pulse = false;
127				rawir.duration = 21845;
128			} else {
129				rawir.pulse = (ir->buf_in[i] & 0x80) == 0;
130				rawir.duration = ((ir->buf_in[i] & 0x7f) + 1) *
131								 RX_RESOLUTION;
132			}
133
134			if (ir_raw_event_store_with_filter(ir->rc, &rawir))
135				event = true;
136		}
137
138		if (event)
139			ir_raw_event_handle(ir->rc);
140	}
141}
142
143static void iguanair_rx(struct urb *urb)
144{
145	struct iguanair *ir;
146	int rc;
147
148	if (!urb)
149		return;
150
151	ir = urb->context;
152	if (!ir) {
153		usb_unlink_urb(urb);
154		return;
155	}
156
157	switch (urb->status) {
158	case 0:
159		process_ir_data(ir, urb->actual_length);
160		break;
161	case -ECONNRESET:
162	case -ENOENT:
163	case -ESHUTDOWN:
164		usb_unlink_urb(urb);
165		return;
166	case -EPIPE:
167	default:
168		dev_dbg(ir->dev, "Error: urb status = %d\n", urb->status);
169		break;
170	}
171
172	rc = usb_submit_urb(urb, GFP_ATOMIC);
173	if (rc && rc != -ENODEV)
174		dev_warn(ir->dev, "failed to resubmit urb: %d\n", rc);
175}
176
177static void iguanair_irq_out(struct urb *urb)
178{
179	struct iguanair *ir = urb->context;
180
181	if (urb->status)
182		dev_dbg(ir->dev, "Error: out urb status = %d\n", urb->status);
183
184	/* if we sent an nop packet, do not expect a response */
185	if (urb->status == 0 && ir->packet->header.cmd == CMD_NOP)
186		complete(&ir->completion);
187}
188
189static int iguanair_send(struct iguanair *ir, unsigned size)
190{
191	int rc;
192
193	reinit_completion(&ir->completion);
194
195	ir->urb_out->transfer_buffer_length = size;
196	rc = usb_submit_urb(ir->urb_out, GFP_KERNEL);
197	if (rc)
198		return rc;
199
200	if (wait_for_completion_timeout(&ir->completion, TIMEOUT) == 0)
201		return -ETIMEDOUT;
202
203	return rc;
204}
205
206static int iguanair_get_features(struct iguanair *ir)
207{
208	int rc;
209
210	/*
211	 * On cold boot, the iguanair initializes on the first packet
212	 * received but does not process that packet. Send an empty
213	 * packet.
214	 */
215	ir->packet->header.start = 0;
216	ir->packet->header.direction = DIR_OUT;
217	ir->packet->header.cmd = CMD_NOP;
218	iguanair_send(ir, sizeof(ir->packet->header));
219
220	ir->packet->header.cmd = CMD_GET_VERSION;
221	rc = iguanair_send(ir, sizeof(ir->packet->header));
222	if (rc) {
223		dev_info(ir->dev, "failed to get version\n");
224		goto out;
225	}
226
227	if (ir->version < 0x205) {
228		dev_err(ir->dev, "firmware 0x%04x is too old\n", ir->version);
229		rc = -ENODEV;
230		goto out;
231	}
232
233	ir->bufsize = 150;
234	ir->cycle_overhead = 65;
235
236	ir->packet->header.cmd = CMD_GET_BUFSIZE;
237
238	rc = iguanair_send(ir, sizeof(ir->packet->header));
239	if (rc) {
240		dev_info(ir->dev, "failed to get buffer size\n");
241		goto out;
242	}
243
244	if (ir->bufsize > BUF_SIZE) {
245		dev_info(ir->dev, "buffer size %u larger than expected\n",
246								ir->bufsize);
247		ir->bufsize = BUF_SIZE;
248	}
249
250	ir->packet->header.cmd = CMD_GET_FEATURES;
251
252	rc = iguanair_send(ir, sizeof(ir->packet->header));
253	if (rc)
254		dev_info(ir->dev, "failed to get features\n");
255out:
256	return rc;
257}
258
259static int iguanair_receiver(struct iguanair *ir, bool enable)
260{
261	ir->packet->header.start = 0;
262	ir->packet->header.direction = DIR_OUT;
263	ir->packet->header.cmd = enable ? CMD_RECEIVER_ON : CMD_RECEIVER_OFF;
264
265	if (enable)
266		ir_raw_event_reset(ir->rc);
267
268	return iguanair_send(ir, sizeof(ir->packet->header));
269}
270
271/*
272 * The iguanair creates the carrier by busy spinning after each half period.
273 * This is counted in CPU cycles, with the CPU running at 24MHz. It is
274 * broken down into 7-cycles and 4-cyles delays, with a preference for
275 * 4-cycle delays, minus the overhead of the loop itself (cycle_overhead).
276 */
277static int iguanair_set_tx_carrier(struct rc_dev *dev, uint32_t carrier)
278{
279	struct iguanair *ir = dev->priv;
280
281	if (carrier < 25000 || carrier > 150000)
282		return -EINVAL;
283
284	if (carrier != ir->carrier) {
285		uint32_t cycles, fours, sevens;
286
287		ir->carrier = carrier;
288
289		cycles = DIV_ROUND_CLOSEST(24000000, carrier * 2) -
290							ir->cycle_overhead;
291
292		/*
293		 * Calculate minimum number of 7 cycles needed so
294		 * we are left with a multiple of 4; so we want to have
295		 * (sevens * 7) & 3 == cycles & 3
296		 */
297		sevens = (4 - cycles) & 3;
298		fours = (cycles - sevens * 7) / 4;
299
300		/*
301		 * The firmware interprets these values as a relative offset
302		 * for a branch. Immediately following the branches, there
303		 * 4 instructions of 7 cycles (2 bytes each) and 110
304		 * instructions of 4 cycles (1 byte each). A relative branch
305		 * of 0 will execute all of them, branch further for less
306		 * cycle burning.
307		 */
308		ir->packet->busy7 = (4 - sevens) * 2;
309		ir->packet->busy4 = 110 - fours;
310	}
311
312	return 0;
313}
314
315static int iguanair_set_tx_mask(struct rc_dev *dev, uint32_t mask)
316{
317	struct iguanair *ir = dev->priv;
318
319	if (mask > 15)
320		return 4;
321
322	ir->packet->channels = mask << 4;
323
324	return 0;
325}
326
327static int iguanair_tx(struct rc_dev *dev, unsigned *txbuf, unsigned count)
328{
329	struct iguanair *ir = dev->priv;
330	unsigned int i, size, p, periods;
331	int rc;
332
333	/* convert from us to carrier periods */
334	for (i = size = 0; i < count; i++) {
335		periods = DIV_ROUND_CLOSEST(txbuf[i] * ir->carrier, 1000000);
336		while (periods) {
337			p = min(periods, 127u);
338			if (size >= ir->bufsize) {
339				rc = -EINVAL;
340				goto out;
341			}
342			ir->packet->payload[size++] = p | ((i & 1) ? 0x80 : 0);
343			periods -= p;
344		}
345	}
346
347	ir->packet->header.start = 0;
348	ir->packet->header.direction = DIR_OUT;
349	ir->packet->header.cmd = CMD_SEND;
350	ir->packet->length = size;
351
352	ir->tx_overflow = false;
353
354	rc = iguanair_send(ir, sizeof(*ir->packet) + size);
355
356	if (rc == 0 && ir->tx_overflow)
357		rc = -EOVERFLOW;
358
359out:
360	return rc ? rc : count;
361}
362
363static int iguanair_open(struct rc_dev *rdev)
364{
365	struct iguanair *ir = rdev->priv;
366	int rc;
367
368	rc = iguanair_receiver(ir, true);
369	if (rc == 0)
370		ir->receiver_on = true;
371
372	return rc;
373}
374
375static void iguanair_close(struct rc_dev *rdev)
376{
377	struct iguanair *ir = rdev->priv;
378	int rc;
379
380	rc = iguanair_receiver(ir, false);
381	ir->receiver_on = false;
382	if (rc && rc != -ENODEV)
383		dev_warn(ir->dev, "failed to disable receiver: %d\n", rc);
384}
385
386static int iguanair_probe(struct usb_interface *intf,
387			  const struct usb_device_id *id)
388{
389	struct usb_device *udev = interface_to_usbdev(intf);
390	struct iguanair *ir;
391	struct rc_dev *rc;
392	int ret, pipein, pipeout;
393	struct usb_host_interface *idesc;
394
395	idesc = intf->cur_altsetting;
396	if (idesc->desc.bNumEndpoints < 2)
397		return -ENODEV;
398
399	ir = kzalloc(sizeof(*ir), GFP_KERNEL);
400	rc = rc_allocate_device(RC_DRIVER_IR_RAW);
401	if (!ir || !rc) {
402		ret = -ENOMEM;
403		goto out;
404	}
405
406	ir->buf_in = usb_alloc_coherent(udev, MAX_IN_PACKET, GFP_KERNEL,
407								&ir->dma_in);
408	ir->packet = usb_alloc_coherent(udev, MAX_OUT_PACKET, GFP_KERNEL,
409								&ir->dma_out);
410	ir->urb_in = usb_alloc_urb(0, GFP_KERNEL);
411	ir->urb_out = usb_alloc_urb(0, GFP_KERNEL);
412
413	if (!ir->buf_in || !ir->packet || !ir->urb_in || !ir->urb_out ||
414	    !usb_endpoint_is_int_in(&idesc->endpoint[0].desc) ||
415	    !usb_endpoint_is_int_out(&idesc->endpoint[1].desc)) {
416		ret = -ENOMEM;
417		goto out;
418	}
419
420	ir->rc = rc;
421	ir->dev = &intf->dev;
422	ir->udev = udev;
423
424	init_completion(&ir->completion);
425	pipeout = usb_sndintpipe(udev,
426				idesc->endpoint[1].desc.bEndpointAddress);
427	usb_fill_int_urb(ir->urb_out, udev, pipeout, ir->packet, MAX_OUT_PACKET,
428						iguanair_irq_out, ir, 1);
429	ir->urb_out->transfer_dma = ir->dma_out;
430	ir->urb_out->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
431
432	pipein = usb_rcvintpipe(udev, idesc->endpoint[0].desc.bEndpointAddress);
433	usb_fill_int_urb(ir->urb_in, udev, pipein, ir->buf_in, MAX_IN_PACKET,
434							 iguanair_rx, ir, 1);
435	ir->urb_in->transfer_dma = ir->dma_in;
436	ir->urb_in->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
437
438	ret = usb_submit_urb(ir->urb_in, GFP_KERNEL);
439	if (ret) {
440		dev_warn(&intf->dev, "failed to submit urb: %d\n", ret);
441		goto out;
442	}
443
444	ret = iguanair_get_features(ir);
445	if (ret)
446		goto out2;
447
448	snprintf(ir->name, sizeof(ir->name),
449		"IguanaWorks USB IR Transceiver version 0x%04x", ir->version);
450
451	usb_make_path(ir->udev, ir->phys, sizeof(ir->phys));
452
453	rc->device_name = ir->name;
454	rc->input_phys = ir->phys;
455	usb_to_input_id(ir->udev, &rc->input_id);
456	rc->dev.parent = &intf->dev;
457	rc->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
458	rc->priv = ir;
459	rc->open = iguanair_open;
460	rc->close = iguanair_close;
461	rc->s_tx_mask = iguanair_set_tx_mask;
462	rc->s_tx_carrier = iguanair_set_tx_carrier;
463	rc->tx_ir = iguanair_tx;
464	rc->driver_name = KBUILD_MODNAME;
465	rc->map_name = RC_MAP_RC6_MCE;
466	rc->min_timeout = 1;
467	rc->timeout = IR_DEFAULT_TIMEOUT;
468	rc->max_timeout = 10 * IR_DEFAULT_TIMEOUT;
469	rc->rx_resolution = RX_RESOLUTION;
470
471	iguanair_set_tx_carrier(rc, 38000);
472	iguanair_set_tx_mask(rc, 0);
473
474	ret = rc_register_device(rc);
475	if (ret < 0) {
476		dev_err(&intf->dev, "failed to register rc device %d", ret);
477		goto out2;
478	}
479
480	usb_set_intfdata(intf, ir);
481
482	return 0;
483out2:
484	usb_kill_urb(ir->urb_in);
485	usb_kill_urb(ir->urb_out);
486out:
487	if (ir) {
488		usb_free_urb(ir->urb_in);
489		usb_free_urb(ir->urb_out);
490		usb_free_coherent(udev, MAX_IN_PACKET, ir->buf_in, ir->dma_in);
491		usb_free_coherent(udev, MAX_OUT_PACKET, ir->packet,
492								ir->dma_out);
493	}
494	rc_free_device(rc);
495	kfree(ir);
496	return ret;
497}
498
499static void iguanair_disconnect(struct usb_interface *intf)
500{
501	struct iguanair *ir = usb_get_intfdata(intf);
502
503	rc_unregister_device(ir->rc);
504	usb_set_intfdata(intf, NULL);
505	usb_kill_urb(ir->urb_in);
506	usb_kill_urb(ir->urb_out);
507	usb_free_urb(ir->urb_in);
508	usb_free_urb(ir->urb_out);
509	usb_free_coherent(ir->udev, MAX_IN_PACKET, ir->buf_in, ir->dma_in);
510	usb_free_coherent(ir->udev, MAX_OUT_PACKET, ir->packet, ir->dma_out);
511	kfree(ir);
512}
513
514static int iguanair_suspend(struct usb_interface *intf, pm_message_t message)
515{
516	struct iguanair *ir = usb_get_intfdata(intf);
517	int rc = 0;
518
519	if (ir->receiver_on) {
520		rc = iguanair_receiver(ir, false);
521		if (rc)
522			dev_warn(ir->dev, "failed to disable receiver for suspend\n");
523	}
524
525	usb_kill_urb(ir->urb_in);
526	usb_kill_urb(ir->urb_out);
527
528	return rc;
529}
530
531static int iguanair_resume(struct usb_interface *intf)
532{
533	struct iguanair *ir = usb_get_intfdata(intf);
534	int rc;
535
536	rc = usb_submit_urb(ir->urb_in, GFP_KERNEL);
537	if (rc)
538		dev_warn(&intf->dev, "failed to submit urb: %d\n", rc);
539
540	if (ir->receiver_on) {
541		rc = iguanair_receiver(ir, true);
542		if (rc)
543			dev_warn(ir->dev, "failed to enable receiver after resume\n");
544	}
545
546	return rc;
547}
548
549static const struct usb_device_id iguanair_table[] = {
550	{ USB_DEVICE(0x1781, 0x0938) },
551	{ }
552};
553
554static struct usb_driver iguanair_driver = {
555	.name =	KBUILD_MODNAME,
556	.probe = iguanair_probe,
557	.disconnect = iguanair_disconnect,
558	.suspend = iguanair_suspend,
559	.resume = iguanair_resume,
560	.reset_resume = iguanair_resume,
561	.id_table = iguanair_table,
562	.soft_unbind = 1	/* we want to disable receiver on unbind */
563};
564
565module_usb_driver(iguanair_driver);
566
567MODULE_DESCRIPTION("IguanaWorks USB IR Transceiver");
568MODULE_AUTHOR("Sean Young <sean@mess.org>");
569MODULE_LICENSE("GPL");
570MODULE_DEVICE_TABLE(usb, iguanair_table);
571
572