summaryrefslogtreecommitdiffstats
path: root/drivers/media/rc/imon_raw.c
blob: 25e56c5b13c02fd6690595e5dfd7cc7e1cb70966 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
// SPDX-License-Identifier: GPL-2.0+
//
// Copyright (C) 2018 Sean Young <sean@mess.org>

#include <linux/module.h>
#include <linux/usb.h>
#include <linux/usb/input.h>
#include <media/rc-core.h>

/* Each bit is 250us */
#define BIT_DURATION 250000

struct imon {
	struct device *dev;
	struct urb *ir_urb;
	struct rc_dev *rcdev;
	u8 ir_buf[8] __aligned(__alignof__(u64));
	char phys[64];
};

/*
 * The first 5 bytes of data represent IR pulse or space. Each bit, starting
 * from highest bit in the first byte, represents 250µs of data. It is 1
 * for space and 0 for pulse.
 *
 * The station sends 10 packets, and the 7th byte will be number 1 to 10, so
 * when we receive 10 we assume all the data has arrived.
 */
static void imon_ir_data(struct imon *imon)
{
	struct ir_raw_event rawir = {};
	u64 d = be64_to_cpup((__be64 *)imon->ir_buf) >> 24;
	int offset = 40;
	int bit;

	dev_dbg(imon->dev, "data: %*ph", 8, imon->ir_buf);

	do {
		bit = fls64(d & (BIT_ULL(offset) - 1));
		if (bit < offset) {
			dev_dbg(imon->dev, "pulse: %d bits", offset - bit);
			rawir.pulse = true;
			rawir.duration = (offset - bit) * BIT_DURATION;
			ir_raw_event_store_with_filter(imon->rcdev, &rawir);

			if (bit == 0)
				break;

			offset = bit;
		}

		bit = fls64(~d & (BIT_ULL(offset) - 1));
		dev_dbg(imon->dev, "space: %d bits", offset - bit);

		rawir.pulse = false;
		rawir.duration = (offset - bit) * BIT_DURATION;
		ir_raw_event_store_with_filter(imon->rcdev, &rawir);

		offset = bit;
	} while (offset > 0);

	if (imon->ir_buf[7] == 0x0a) {
		ir_raw_event_set_idle(imon->rcdev, true);
		ir_raw_event_handle(imon->rcdev);
	}
}

static void imon_ir_rx(struct urb *urb)
{
	struct imon *imon = urb->context;
	int ret;

	switch (urb->status) {
	case 0:
		if (imon->ir_buf[7] != 0xff)
			imon_ir_data(imon);
		break;
	case -ECONNRESET:
	case -ENOENT:
	case -ESHUTDOWN:
		usb_unlink_urb(urb);
		return;
	case -EPIPE:
	default:
		dev_dbg(imon->dev, "error: urb status = %d", urb->status);
		break;
	}

	ret = usb_submit_urb(urb, GFP_ATOMIC);
	if (ret && ret != -ENODEV)
		dev_warn(imon->dev, "failed to resubmit urb: %d", ret);
}

static int imon_probe(struct usb_interface *intf,
		      const struct usb_device_id *id)
{
	struct usb_endpoint_descriptor *ir_ep = NULL;
	struct usb_host_interface *idesc;
	struct usb_device *udev;
	struct rc_dev *rcdev;
	struct imon *imon;
	int i, ret;

	udev = interface_to_usbdev(intf);
	idesc = intf->cur_altsetting;

	for (i = 0; i < idesc->desc.bNumEndpoints; i++) {
		struct usb_endpoint_descriptor *ep = &idesc->endpoint[i].desc;

		if (usb_endpoint_is_int_in(ep)) {
			ir_ep = ep;
			break;
		}
	}

	if (!ir_ep) {
		dev_err(&intf->dev, "IR endpoint missing");
		return -ENODEV;
	}

	imon = devm_kmalloc(&intf->dev, sizeof(*imon), GFP_KERNEL);
	if (!imon)
		return -ENOMEM;

	imon->ir_urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!imon->ir_urb)
		return -ENOMEM;

	imon->dev = &intf->dev;
	usb_fill_int_urb(imon->ir_urb, udev,
			 usb_rcvintpipe(udev, ir_ep->bEndpointAddress),
			 imon->ir_buf, sizeof(imon->ir_buf),
			 imon_ir_rx, imon, ir_ep->bInterval);

	rcdev = devm_rc_allocate_device(&intf->dev, RC_DRIVER_IR_RAW);
	if (!rcdev) {
		ret = -ENOMEM;
		goto free_urb;
	}

	usb_make_path(udev, imon->phys, sizeof(imon->phys));

	rcdev->device_name = "iMON Station";
	rcdev->driver_name = KBUILD_MODNAME;
	rcdev->input_phys = imon->phys;
	usb_to_input_id(udev, &rcdev->input_id);
	rcdev->dev.parent = &intf->dev;
	rcdev->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
	rcdev->map_name = RC_MAP_IMON_RSC;
	rcdev->rx_resolution = BIT_DURATION;
	rcdev->priv = imon;

	ret = devm_rc_register_device(&intf->dev, rcdev);
	if (ret)
		goto free_urb;

	imon->rcdev = rcdev;

	ret = usb_submit_urb(imon->ir_urb, GFP_KERNEL);
	if (ret)
		goto free_urb;

	usb_set_intfdata(intf, imon);

	return 0;

free_urb:
	usb_free_urb(imon->ir_urb);
	return ret;
}

static void imon_disconnect(struct usb_interface *intf)
{
	struct imon *imon = usb_get_intfdata(intf);

	usb_kill_urb(imon->ir_urb);
	usb_free_urb(imon->ir_urb);
}

static const struct usb_device_id imon_table[] = {
	/* SoundGraph iMON (IR only) -- sg_imon.inf */
	{ USB_DEVICE(0x04e8, 0xff30) },
	{}
};

static struct usb_driver imon_driver = {
	.name = KBUILD_MODNAME,
	.probe = imon_probe,
	.disconnect = imon_disconnect,
	.id_table = imon_table
};

module_usb_driver(imon_driver);

MODULE_DESCRIPTION("Early raw iMON IR devices");
MODULE_AUTHOR("Sean Young <sean@mess.org>");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(usb, imon_table);