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_overflow(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		return;
154
155	switch (urb->status) {
156	case 0:
157		process_ir_data(ir, urb->actual_length);
158		break;
159	case -ECONNRESET:
160	case -ENOENT:
161	case -ESHUTDOWN:
162		return;
163	case -EPIPE:
164	default:
165		dev_dbg(ir->dev, "Error: urb status = %d\n", urb->status);
166		break;
167	}
168
169	rc = usb_submit_urb(urb, GFP_ATOMIC);
170	if (rc && rc != -ENODEV)
171		dev_warn(ir->dev, "failed to resubmit urb: %d\n", rc);
172}
173
174static void iguanair_irq_out(struct urb *urb)
175{
176	struct iguanair *ir = urb->context;
177
178	if (urb->status)
179		dev_dbg(ir->dev, "Error: out urb status = %d\n", urb->status);
180
181	/* if we sent an nop packet, do not expect a response */
182	if (urb->status == 0 && ir->packet->header.cmd == CMD_NOP)
183		complete(&ir->completion);
184}
185
186static int iguanair_send(struct iguanair *ir, unsigned size)
187{
188	int rc;
189
190	reinit_completion(&ir->completion);
191
192	ir->urb_out->transfer_buffer_length = size;
193	rc = usb_submit_urb(ir->urb_out, GFP_KERNEL);
194	if (rc)
195		return rc;
196
197	if (wait_for_completion_timeout(&ir->completion, TIMEOUT) == 0)
198		return -ETIMEDOUT;
199
200	return rc;
201}
202
203static int iguanair_get_features(struct iguanair *ir)
204{
205	int rc;
206
207	/*
208	 * On cold boot, the iguanair initializes on the first packet
209	 * received but does not process that packet. Send an empty
210	 * packet.
211	 */
212	ir->packet->header.start = 0;
213	ir->packet->header.direction = DIR_OUT;
214	ir->packet->header.cmd = CMD_NOP;
215	iguanair_send(ir, sizeof(ir->packet->header));
216
217	ir->packet->header.cmd = CMD_GET_VERSION;
218	rc = iguanair_send(ir, sizeof(ir->packet->header));
219	if (rc) {
220		dev_info(ir->dev, "failed to get version\n");
221		goto out;
222	}
223
224	if (ir->version < 0x205) {
225		dev_err(ir->dev, "firmware 0x%04x is too old\n", ir->version);
226		rc = -ENODEV;
227		goto out;
228	}
229
230	ir->bufsize = 150;
231	ir->cycle_overhead = 65;
232
233	ir->packet->header.cmd = CMD_GET_BUFSIZE;
234
235	rc = iguanair_send(ir, sizeof(ir->packet->header));
236	if (rc) {
237		dev_info(ir->dev, "failed to get buffer size\n");
238		goto out;
239	}
240
241	if (ir->bufsize > BUF_SIZE) {
242		dev_info(ir->dev, "buffer size %u larger than expected\n",
243								ir->bufsize);
244		ir->bufsize = BUF_SIZE;
245	}
246
247	ir->packet->header.cmd = CMD_GET_FEATURES;
248
249	rc = iguanair_send(ir, sizeof(ir->packet->header));
250	if (rc)
251		dev_info(ir->dev, "failed to get features\n");
252out:
253	return rc;
254}
255
256static int iguanair_receiver(struct iguanair *ir, bool enable)
257{
258	ir->packet->header.start = 0;
259	ir->packet->header.direction = DIR_OUT;
260	ir->packet->header.cmd = enable ? CMD_RECEIVER_ON : CMD_RECEIVER_OFF;
261
262	return iguanair_send(ir, sizeof(ir->packet->header));
263}
264
265/*
266 * The iguanair creates the carrier by busy spinning after each half period.
267 * This is counted in CPU cycles, with the CPU running at 24MHz. It is
268 * broken down into 7-cycles and 4-cyles delays, with a preference for
269 * 4-cycle delays, minus the overhead of the loop itself (cycle_overhead).
270 */
271static int iguanair_set_tx_carrier(struct rc_dev *dev, uint32_t carrier)
272{
273	struct iguanair *ir = dev->priv;
274
275	if (carrier < 25000 || carrier > 150000)
276		return -EINVAL;
277
278	if (carrier != ir->carrier) {
279		uint32_t cycles, fours, sevens;
280
281		ir->carrier = carrier;
282
283		cycles = DIV_ROUND_CLOSEST(24000000, carrier * 2) -
284							ir->cycle_overhead;
285
286		/*
287		 * Calculate minimum number of 7 cycles needed so
288		 * we are left with a multiple of 4; so we want to have
289		 * (sevens * 7) & 3 == cycles & 3
290		 */
291		sevens = (4 - cycles) & 3;
292		fours = (cycles - sevens * 7) / 4;
293
294		/*
295		 * The firmware interprets these values as a relative offset
296		 * for a branch. Immediately following the branches, there
297		 * 4 instructions of 7 cycles (2 bytes each) and 110
298		 * instructions of 4 cycles (1 byte each). A relative branch
299		 * of 0 will execute all of them, branch further for less
300		 * cycle burning.
301		 */
302		ir->packet->busy7 = (4 - sevens) * 2;
303		ir->packet->busy4 = 110 - fours;
304	}
305
306	return 0;
307}
308
309static int iguanair_set_tx_mask(struct rc_dev *dev, uint32_t mask)
310{
311	struct iguanair *ir = dev->priv;
312
313	if (mask > 15)
314		return 4;
315
316	ir->packet->channels = mask << 4;
317
318	return 0;
319}
320
321static int iguanair_tx(struct rc_dev *dev, unsigned *txbuf, unsigned count)
322{
323	struct iguanair *ir = dev->priv;
324	unsigned int i, size, p, periods;
325	int rc;
326
327	/* convert from us to carrier periods */
328	for (i = size = 0; i < count; i++) {
329		periods = DIV_ROUND_CLOSEST(txbuf[i] * ir->carrier, 1000000);
330		while (periods) {
331			p = min(periods, 127u);
332			if (size >= ir->bufsize) {
333				rc = -EINVAL;
334				goto out;
335			}
336			ir->packet->payload[size++] = p | ((i & 1) ? 0x80 : 0);
337			periods -= p;
338		}
339	}
340
341	ir->packet->header.start = 0;
342	ir->packet->header.direction = DIR_OUT;
343	ir->packet->header.cmd = CMD_SEND;
344	ir->packet->length = size;
345
346	ir->tx_overflow = false;
347
348	rc = iguanair_send(ir, sizeof(*ir->packet) + size);
349
350	if (rc == 0 && ir->tx_overflow)
351		rc = -EOVERFLOW;
352
353out:
354	return rc ? rc : count;
355}
356
357static int iguanair_open(struct rc_dev *rdev)
358{
359	struct iguanair *ir = rdev->priv;
360	int rc;
361
362	rc = iguanair_receiver(ir, true);
363	if (rc == 0)
364		ir->receiver_on = true;
365
366	return rc;
367}
368
369static void iguanair_close(struct rc_dev *rdev)
370{
371	struct iguanair *ir = rdev->priv;
372	int rc;
373
374	rc = iguanair_receiver(ir, false);
375	ir->receiver_on = false;
376	if (rc && rc != -ENODEV)
377		dev_warn(ir->dev, "failed to disable receiver: %d\n", rc);
378}
379
380static int iguanair_probe(struct usb_interface *intf,
381			  const struct usb_device_id *id)
382{
383	struct usb_device *udev = interface_to_usbdev(intf);
384	struct iguanair *ir;
385	struct rc_dev *rc;
386	int ret, pipein, pipeout;
387	struct usb_host_interface *idesc;
388
389	idesc = intf->cur_altsetting;
390	if (idesc->desc.bNumEndpoints < 2)
391		return -ENODEV;
392
393	ir = kzalloc(sizeof(*ir), GFP_KERNEL);
394	rc = rc_allocate_device(RC_DRIVER_IR_RAW);
395	if (!ir || !rc) {
396		ret = -ENOMEM;
397		goto out;
398	}
399
400	ir->buf_in = usb_alloc_coherent(udev, MAX_IN_PACKET, GFP_KERNEL,
401								&ir->dma_in);
402	ir->packet = usb_alloc_coherent(udev, MAX_OUT_PACKET, GFP_KERNEL,
403								&ir->dma_out);
404	ir->urb_in = usb_alloc_urb(0, GFP_KERNEL);
405	ir->urb_out = usb_alloc_urb(0, GFP_KERNEL);
406
407	if (!ir->buf_in || !ir->packet || !ir->urb_in || !ir->urb_out ||
408	    !usb_endpoint_is_int_in(&idesc->endpoint[0].desc) ||
409	    !usb_endpoint_is_int_out(&idesc->endpoint[1].desc)) {
410		ret = -ENOMEM;
411		goto out;
412	}
413
414	ir->rc = rc;
415	ir->dev = &intf->dev;
416	ir->udev = udev;
417
418	init_completion(&ir->completion);
419	pipeout = usb_sndintpipe(udev,
420				idesc->endpoint[1].desc.bEndpointAddress);
421	usb_fill_int_urb(ir->urb_out, udev, pipeout, ir->packet, MAX_OUT_PACKET,
422						iguanair_irq_out, ir, 1);
423	ir->urb_out->transfer_dma = ir->dma_out;
424	ir->urb_out->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
425
426	pipein = usb_rcvintpipe(udev, idesc->endpoint[0].desc.bEndpointAddress);
427	usb_fill_int_urb(ir->urb_in, udev, pipein, ir->buf_in, MAX_IN_PACKET,
428							 iguanair_rx, ir, 1);
429	ir->urb_in->transfer_dma = ir->dma_in;
430	ir->urb_in->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
431
432	ret = usb_submit_urb(ir->urb_in, GFP_KERNEL);
433	if (ret) {
434		dev_warn(&intf->dev, "failed to submit urb: %d\n", ret);
435		goto out;
436	}
437
438	ret = iguanair_get_features(ir);
439	if (ret)
440		goto out2;
441
442	snprintf(ir->name, sizeof(ir->name),
443		"IguanaWorks USB IR Transceiver version 0x%04x", ir->version);
444
445	usb_make_path(ir->udev, ir->phys, sizeof(ir->phys));
446
447	rc->device_name = ir->name;
448	rc->input_phys = ir->phys;
449	usb_to_input_id(ir->udev, &rc->input_id);
450	rc->dev.parent = &intf->dev;
451	rc->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
452	rc->priv = ir;
453	rc->open = iguanair_open;
454	rc->close = iguanair_close;
455	rc->s_tx_mask = iguanair_set_tx_mask;
456	rc->s_tx_carrier = iguanair_set_tx_carrier;
457	rc->tx_ir = iguanair_tx;
458	rc->driver_name = KBUILD_MODNAME;
459	rc->map_name = RC_MAP_RC6_MCE;
460	rc->min_timeout = 1;
461	rc->timeout = IR_DEFAULT_TIMEOUT;
462	rc->max_timeout = 10 * IR_DEFAULT_TIMEOUT;
463	rc->rx_resolution = RX_RESOLUTION;
464
465	iguanair_set_tx_carrier(rc, 38000);
466	iguanair_set_tx_mask(rc, 0);
467
468	ret = rc_register_device(rc);
469	if (ret < 0) {
470		dev_err(&intf->dev, "failed to register rc device %d", ret);
471		goto out2;
472	}
473
474	usb_set_intfdata(intf, ir);
475
476	return 0;
477out2:
478	usb_kill_urb(ir->urb_in);
479	usb_kill_urb(ir->urb_out);
480out:
481	if (ir) {
482		usb_free_urb(ir->urb_in);
483		usb_free_urb(ir->urb_out);
484		usb_free_coherent(udev, MAX_IN_PACKET, ir->buf_in, ir->dma_in);
485		usb_free_coherent(udev, MAX_OUT_PACKET, ir->packet,
486								ir->dma_out);
487	}
488	rc_free_device(rc);
489	kfree(ir);
490	return ret;
491}
492
493static void iguanair_disconnect(struct usb_interface *intf)
494{
495	struct iguanair *ir = usb_get_intfdata(intf);
496
497	rc_unregister_device(ir->rc);
498	usb_set_intfdata(intf, NULL);
499	usb_kill_urb(ir->urb_in);
500	usb_kill_urb(ir->urb_out);
501	usb_free_urb(ir->urb_in);
502	usb_free_urb(ir->urb_out);
503	usb_free_coherent(ir->udev, MAX_IN_PACKET, ir->buf_in, ir->dma_in);
504	usb_free_coherent(ir->udev, MAX_OUT_PACKET, ir->packet, ir->dma_out);
505	kfree(ir);
506}
507
508static int iguanair_suspend(struct usb_interface *intf, pm_message_t message)
509{
510	struct iguanair *ir = usb_get_intfdata(intf);
511	int rc = 0;
512
513	if (ir->receiver_on) {
514		rc = iguanair_receiver(ir, false);
515		if (rc)
516			dev_warn(ir->dev, "failed to disable receiver for suspend\n");
517	}
518
519	usb_kill_urb(ir->urb_in);
520	usb_kill_urb(ir->urb_out);
521
522	return rc;
523}
524
525static int iguanair_resume(struct usb_interface *intf)
526{
527	struct iguanair *ir = usb_get_intfdata(intf);
528	int rc;
529
530	rc = usb_submit_urb(ir->urb_in, GFP_KERNEL);
531	if (rc)
532		dev_warn(&intf->dev, "failed to submit urb: %d\n", rc);
533
534	if (ir->receiver_on) {
535		rc = iguanair_receiver(ir, true);
536		if (rc)
537			dev_warn(ir->dev, "failed to enable receiver after resume\n");
538	}
539
540	return rc;
541}
542
543static const struct usb_device_id iguanair_table[] = {
544	{ USB_DEVICE(0x1781, 0x0938) },
545	{ }
546};
547
548static struct usb_driver iguanair_driver = {
549	.name =	KBUILD_MODNAME,
550	.probe = iguanair_probe,
551	.disconnect = iguanair_disconnect,
552	.suspend = iguanair_suspend,
553	.resume = iguanair_resume,
554	.reset_resume = iguanair_resume,
555	.id_table = iguanair_table,
556	.soft_unbind = 1	/* we want to disable receiver on unbind */
557};
558
559module_usb_driver(iguanair_driver);
560
561MODULE_DESCRIPTION("IguanaWorks USB IR Transceiver");
562MODULE_AUTHOR("Sean Young <sean@mess.org>");
563MODULE_LICENSE("GPL");
564MODULE_DEVICE_TABLE(usb, iguanair_table);
565
566