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