1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * TechnoTrend USB IR Receiver
4 *
5 * Copyright (C) 2012 Sean Young <sean@mess.org>
6 */
7
8#include <linux/module.h>
9#include <linux/usb.h>
10#include <linux/usb/input.h>
11#include <linux/slab.h>
12#include <linux/leds.h>
13#include <media/rc-core.h>
14
15#define DRIVER_NAME	"ttusbir"
16#define DRIVER_DESC	"TechnoTrend USB IR Receiver"
17/*
18 * The Windows driver uses 8 URBS, the original lirc drivers has a
19 * configurable amount (2 default, 4 max). This device generates about 125
20 * messages per second (!), whether IR is idle or not.
21 */
22#define NUM_URBS	4
23#define US_PER_BYTE	62
24#define US_PER_BIT	(US_PER_BYTE / 8)
25
26struct ttusbir {
27	struct rc_dev *rc;
28	struct device *dev;
29	struct usb_device *udev;
30
31	struct urb *urb[NUM_URBS];
32
33	struct led_classdev led;
34	struct urb *bulk_urb;
35	uint8_t bulk_buffer[5];
36	int bulk_out_endp, iso_in_endp;
37	bool led_on, is_led_on;
38	atomic_t led_complete;
39
40	char phys[64];
41};
42
43static enum led_brightness ttusbir_brightness_get(struct led_classdev *led_dev)
44{
45	struct ttusbir *tt = container_of(led_dev, struct ttusbir, led);
46
47	return tt->led_on ? LED_FULL : LED_OFF;
48}
49
50static void ttusbir_set_led(struct ttusbir *tt)
51{
52	int ret;
53
54	smp_mb();
55
56	if (tt->led_on != tt->is_led_on && tt->udev &&
57				atomic_add_unless(&tt->led_complete, 1, 1)) {
58		tt->bulk_buffer[4] = tt->is_led_on = tt->led_on;
59		ret = usb_submit_urb(tt->bulk_urb, GFP_ATOMIC);
60		if (ret) {
61			dev_warn(tt->dev, "failed to submit bulk urb: %d\n",
62									ret);
63			atomic_dec(&tt->led_complete);
64		}
65	}
66}
67
68static void ttusbir_brightness_set(struct led_classdev *led_dev, enum
69						led_brightness brightness)
70{
71	struct ttusbir *tt = container_of(led_dev, struct ttusbir, led);
72
73	tt->led_on = brightness != LED_OFF;
74
75	ttusbir_set_led(tt);
76}
77
78/*
79 * The urb cannot be reused until the urb completes
80 */
81static void ttusbir_bulk_complete(struct urb *urb)
82{
83	struct ttusbir *tt = urb->context;
84
85	atomic_dec(&tt->led_complete);
86
87	switch (urb->status) {
88	case 0:
89		break;
90	case -ECONNRESET:
91	case -ENOENT:
92	case -ESHUTDOWN:
93		usb_unlink_urb(urb);
94		return;
95	case -EPIPE:
96	default:
97		dev_dbg(tt->dev, "Error: urb status = %d\n", urb->status);
98		break;
99	}
100
101	ttusbir_set_led(tt);
102}
103
104/*
105 * The data is one bit per sample, a set bit signifying silence and samples
106 * being MSB first. Bit 0 can contain garbage so take it to be whatever
107 * bit 1 is, so we don't have unexpected edges.
108 */
109static void ttusbir_process_ir_data(struct ttusbir *tt, uint8_t *buf)
110{
111	struct ir_raw_event rawir = {};
112	unsigned i, v, b;
113	bool event = false;
114
115	for (i = 0; i < 128; i++) {
116		v = buf[i] & 0xfe;
117		switch (v) {
118		case 0xfe:
119			rawir.pulse = false;
120			rawir.duration = US_PER_BYTE;
121			if (ir_raw_event_store_with_filter(tt->rc, &rawir))
122				event = true;
123			break;
124		case 0:
125			rawir.pulse = true;
126			rawir.duration = US_PER_BYTE;
127			if (ir_raw_event_store_with_filter(tt->rc, &rawir))
128				event = true;
129			break;
130		default:
131			/* one edge per byte */
132			if (v & 2) {
133				b = ffz(v | 1);
134				rawir.pulse = true;
135			} else {
136				b = ffs(v) - 1;
137				rawir.pulse = false;
138			}
139
140			rawir.duration = US_PER_BIT * (8 - b);
141			if (ir_raw_event_store_with_filter(tt->rc, &rawir))
142				event = true;
143
144			rawir.pulse = !rawir.pulse;
145			rawir.duration = US_PER_BIT * b;
146			if (ir_raw_event_store_with_filter(tt->rc, &rawir))
147				event = true;
148			break;
149		}
150	}
151
152	/* don't wakeup when there's nothing to do */
153	if (event)
154		ir_raw_event_handle(tt->rc);
155}
156
157static void ttusbir_urb_complete(struct urb *urb)
158{
159	struct ttusbir *tt = urb->context;
160	int rc;
161
162	switch (urb->status) {
163	case 0:
164		ttusbir_process_ir_data(tt, urb->transfer_buffer);
165		break;
166	case -ECONNRESET:
167	case -ENOENT:
168	case -ESHUTDOWN:
169		usb_unlink_urb(urb);
170		return;
171	case -EPIPE:
172	default:
173		dev_dbg(tt->dev, "Error: urb status = %d\n", urb->status);
174		break;
175	}
176
177	rc = usb_submit_urb(urb, GFP_ATOMIC);
178	if (rc && rc != -ENODEV)
179		dev_warn(tt->dev, "failed to resubmit urb: %d\n", rc);
180}
181
182static int ttusbir_probe(struct usb_interface *intf,
183			 const struct usb_device_id *id)
184{
185	struct ttusbir *tt;
186	struct usb_interface_descriptor *idesc;
187	struct usb_endpoint_descriptor *desc;
188	struct rc_dev *rc;
189	int i, j, ret;
190	int altsetting = -1;
191
192	tt = kzalloc(sizeof(*tt), GFP_KERNEL);
193	rc = rc_allocate_device(RC_DRIVER_IR_RAW);
194	if (!tt || !rc) {
195		ret = -ENOMEM;
196		goto out;
197	}
198
199	/* find the correct alt setting */
200	for (i = 0; i < intf->num_altsetting && altsetting == -1; i++) {
201		int max_packet, bulk_out_endp = -1, iso_in_endp = -1;
202
203		idesc = &intf->altsetting[i].desc;
204
205		for (j = 0; j < idesc->bNumEndpoints; j++) {
206			desc = &intf->altsetting[i].endpoint[j].desc;
207			max_packet = le16_to_cpu(desc->wMaxPacketSize);
208			if (usb_endpoint_dir_in(desc) &&
209					usb_endpoint_xfer_isoc(desc) &&
210					max_packet == 0x10)
211				iso_in_endp = j;
212			else if (usb_endpoint_dir_out(desc) &&
213					usb_endpoint_xfer_bulk(desc) &&
214					max_packet == 0x20)
215				bulk_out_endp = j;
216
217			if (bulk_out_endp != -1 && iso_in_endp != -1) {
218				tt->bulk_out_endp = bulk_out_endp;
219				tt->iso_in_endp = iso_in_endp;
220				altsetting = i;
221				break;
222			}
223		}
224	}
225
226	if (altsetting == -1) {
227		dev_err(&intf->dev, "cannot find expected altsetting\n");
228		ret = -ENODEV;
229		goto out;
230	}
231
232	tt->dev = &intf->dev;
233	tt->udev = interface_to_usbdev(intf);
234	tt->rc = rc;
235
236	ret = usb_set_interface(tt->udev, 0, altsetting);
237	if (ret)
238		goto out;
239
240	for (i = 0; i < NUM_URBS; i++) {
241		struct urb *urb = usb_alloc_urb(8, GFP_KERNEL);
242		void *buffer;
243
244		if (!urb) {
245			ret = -ENOMEM;
246			goto out;
247		}
248
249		urb->dev = tt->udev;
250		urb->context = tt;
251		urb->pipe = usb_rcvisocpipe(tt->udev, tt->iso_in_endp);
252		urb->interval = 1;
253		buffer = usb_alloc_coherent(tt->udev, 128, GFP_KERNEL,
254						&urb->transfer_dma);
255		if (!buffer) {
256			usb_free_urb(urb);
257			ret = -ENOMEM;
258			goto out;
259		}
260		urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP | URB_ISO_ASAP;
261		urb->transfer_buffer = buffer;
262		urb->complete = ttusbir_urb_complete;
263		urb->number_of_packets = 8;
264		urb->transfer_buffer_length = 128;
265
266		for (j = 0; j < 8; j++) {
267			urb->iso_frame_desc[j].offset = j * 16;
268			urb->iso_frame_desc[j].length = 16;
269		}
270
271		tt->urb[i] = urb;
272	}
273
274	tt->bulk_urb = usb_alloc_urb(0, GFP_KERNEL);
275	if (!tt->bulk_urb) {
276		ret = -ENOMEM;
277		goto out;
278	}
279
280	tt->bulk_buffer[0] = 0xaa;
281	tt->bulk_buffer[1] = 0x01;
282	tt->bulk_buffer[2] = 0x05;
283	tt->bulk_buffer[3] = 0x01;
284
285	usb_fill_bulk_urb(tt->bulk_urb, tt->udev, usb_sndbulkpipe(tt->udev,
286		tt->bulk_out_endp), tt->bulk_buffer, sizeof(tt->bulk_buffer),
287						ttusbir_bulk_complete, tt);
288
289	tt->led.name = "ttusbir:green:power";
290	tt->led.default_trigger = "rc-feedback";
291	tt->led.brightness_set = ttusbir_brightness_set;
292	tt->led.brightness_get = ttusbir_brightness_get;
293	tt->is_led_on = tt->led_on = true;
294	atomic_set(&tt->led_complete, 0);
295	ret = led_classdev_register(&intf->dev, &tt->led);
296	if (ret)
297		goto out;
298
299	usb_make_path(tt->udev, tt->phys, sizeof(tt->phys));
300
301	rc->device_name = DRIVER_DESC;
302	rc->input_phys = tt->phys;
303	usb_to_input_id(tt->udev, &rc->input_id);
304	rc->dev.parent = &intf->dev;
305	rc->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
306	rc->priv = tt;
307	rc->driver_name = DRIVER_NAME;
308	rc->map_name = RC_MAP_TT_1500;
309	rc->min_timeout = 1;
310	rc->timeout = IR_DEFAULT_TIMEOUT;
311	rc->max_timeout = 10 * IR_DEFAULT_TIMEOUT;
312
313	/*
314	 * The precision is US_PER_BIT, but since every 8th bit can be
315	 * overwritten with garbage the accuracy is at best 2 * US_PER_BIT.
316	 */
317	rc->rx_resolution = 2 * US_PER_BIT;
318
319	ret = rc_register_device(rc);
320	if (ret) {
321		dev_err(&intf->dev, "failed to register rc device %d\n", ret);
322		goto out2;
323	}
324
325	usb_set_intfdata(intf, tt);
326
327	for (i = 0; i < NUM_URBS; i++) {
328		ret = usb_submit_urb(tt->urb[i], GFP_KERNEL);
329		if (ret) {
330			dev_err(tt->dev, "failed to submit urb %d\n", ret);
331			goto out3;
332		}
333	}
334
335	return 0;
336out3:
337	rc_unregister_device(rc);
338	rc = NULL;
339out2:
340	led_classdev_unregister(&tt->led);
341out:
342	if (tt) {
343		for (i = 0; i < NUM_URBS && tt->urb[i]; i++) {
344			struct urb *urb = tt->urb[i];
345
346			usb_kill_urb(urb);
347			usb_free_coherent(tt->udev, 128, urb->transfer_buffer,
348							urb->transfer_dma);
349			usb_free_urb(urb);
350		}
351		usb_kill_urb(tt->bulk_urb);
352		usb_free_urb(tt->bulk_urb);
353		kfree(tt);
354	}
355	rc_free_device(rc);
356
357	return ret;
358}
359
360static void ttusbir_disconnect(struct usb_interface *intf)
361{
362	struct ttusbir *tt = usb_get_intfdata(intf);
363	struct usb_device *udev = tt->udev;
364	int i;
365
366	tt->udev = NULL;
367
368	rc_unregister_device(tt->rc);
369	led_classdev_unregister(&tt->led);
370	for (i = 0; i < NUM_URBS; i++) {
371		usb_kill_urb(tt->urb[i]);
372		usb_free_coherent(udev, 128, tt->urb[i]->transfer_buffer,
373						tt->urb[i]->transfer_dma);
374		usb_free_urb(tt->urb[i]);
375	}
376	usb_kill_urb(tt->bulk_urb);
377	usb_free_urb(tt->bulk_urb);
378	usb_set_intfdata(intf, NULL);
379	kfree(tt);
380}
381
382static int ttusbir_suspend(struct usb_interface *intf, pm_message_t message)
383{
384	struct ttusbir *tt = usb_get_intfdata(intf);
385	int i;
386
387	for (i = 0; i < NUM_URBS; i++)
388		usb_kill_urb(tt->urb[i]);
389
390	led_classdev_suspend(&tt->led);
391	usb_kill_urb(tt->bulk_urb);
392
393	return 0;
394}
395
396static int ttusbir_resume(struct usb_interface *intf)
397{
398	struct ttusbir *tt = usb_get_intfdata(intf);
399	int i, rc;
400
401	tt->is_led_on = true;
402	led_classdev_resume(&tt->led);
403
404	for (i = 0; i < NUM_URBS; i++) {
405		rc = usb_submit_urb(tt->urb[i], GFP_KERNEL);
406		if (rc) {
407			dev_warn(tt->dev, "failed to submit urb: %d\n", rc);
408			break;
409		}
410	}
411
412	return rc;
413}
414
415static const struct usb_device_id ttusbir_table[] = {
416	{ USB_DEVICE(0x0b48, 0x2003) },
417	{ }
418};
419
420static struct usb_driver ttusbir_driver = {
421	.name = DRIVER_NAME,
422	.id_table = ttusbir_table,
423	.probe = ttusbir_probe,
424	.suspend = ttusbir_suspend,
425	.resume = ttusbir_resume,
426	.reset_resume = ttusbir_resume,
427	.disconnect = ttusbir_disconnect,
428};
429
430module_usb_driver(ttusbir_driver);
431
432MODULE_DESCRIPTION(DRIVER_DESC);
433MODULE_AUTHOR("Sean Young <sean@mess.org>");
434MODULE_LICENSE("GPL");
435MODULE_DEVICE_TABLE(usb, ttusbir_table);
436
437