1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // Copyright (C) 2018 Sean Young <sean@mess.org>
4
5 #include <linux/module.h>
6 #include <linux/usb.h>
7 #include <linux/usb/input.h>
8 #include <media/rc-core.h>
9
10 /* Each bit is 250us */
11 #define BIT_DURATION 250000
12
13 struct imon {
14 struct device *dev;
15 struct urb *ir_urb;
16 struct rc_dev *rcdev;
17 u8 ir_buf[8];
18 char phys[64];
19 };
20
21 /*
22 * ffs/find_next_bit() searches in the wrong direction, so open-code our own.
23 */
is_bit_set(const u8 * buf,int bit)24 static inline int is_bit_set(const u8 *buf, int bit)
25 {
26 return buf[bit / 8] & (0x80 >> (bit & 7));
27 }
28
imon_ir_data(struct imon * imon)29 static void imon_ir_data(struct imon *imon)
30 {
31 DEFINE_IR_RAW_EVENT(rawir);
32 int offset = 0, size = 5 * 8;
33 int bit;
34
35 dev_dbg(imon->dev, "data: %*ph", 8, imon->ir_buf);
36
37 while (offset < size) {
38 bit = offset;
39 while (!is_bit_set(imon->ir_buf, bit) && bit < size)
40 bit++;
41 dev_dbg(imon->dev, "pulse: %d bits", bit - offset);
42 if (bit > offset) {
43 rawir.pulse = true;
44 rawir.duration = (bit - offset) * BIT_DURATION;
45 ir_raw_event_store_with_filter(imon->rcdev, &rawir);
46 }
47
48 if (bit >= size)
49 break;
50
51 offset = bit;
52 while (is_bit_set(imon->ir_buf, bit) && bit < size)
53 bit++;
54 dev_dbg(imon->dev, "space: %d bits", bit - offset);
55
56 rawir.pulse = false;
57 rawir.duration = (bit - offset) * BIT_DURATION;
58 ir_raw_event_store_with_filter(imon->rcdev, &rawir);
59
60 offset = bit;
61 }
62
63 if (imon->ir_buf[7] == 0x0a) {
64 ir_raw_event_set_idle(imon->rcdev, true);
65 ir_raw_event_handle(imon->rcdev);
66 }
67 }
68
imon_ir_rx(struct urb * urb)69 static void imon_ir_rx(struct urb *urb)
70 {
71 struct imon *imon = urb->context;
72 int ret;
73
74 switch (urb->status) {
75 case 0:
76 if (imon->ir_buf[7] != 0xff)
77 imon_ir_data(imon);
78 break;
79 case -ECONNRESET:
80 case -ENOENT:
81 case -ESHUTDOWN:
82 usb_unlink_urb(urb);
83 return;
84 case -EPIPE:
85 default:
86 dev_dbg(imon->dev, "error: urb status = %d", urb->status);
87 break;
88 }
89
90 ret = usb_submit_urb(urb, GFP_ATOMIC);
91 if (ret && ret != -ENODEV)
92 dev_warn(imon->dev, "failed to resubmit urb: %d", ret);
93 }
94
imon_probe(struct usb_interface * intf,const struct usb_device_id * id)95 static int imon_probe(struct usb_interface *intf,
96 const struct usb_device_id *id)
97 {
98 struct usb_endpoint_descriptor *ir_ep = NULL;
99 struct usb_host_interface *idesc;
100 struct usb_device *udev;
101 struct rc_dev *rcdev;
102 struct imon *imon;
103 int i, ret;
104
105 udev = interface_to_usbdev(intf);
106 idesc = intf->cur_altsetting;
107
108 for (i = 0; i < idesc->desc.bNumEndpoints; i++) {
109 struct usb_endpoint_descriptor *ep = &idesc->endpoint[i].desc;
110
111 if (usb_endpoint_is_int_in(ep)) {
112 ir_ep = ep;
113 break;
114 }
115 }
116
117 if (!ir_ep) {
118 dev_err(&intf->dev, "IR endpoint missing");
119 return -ENODEV;
120 }
121
122 imon = devm_kmalloc(&intf->dev, sizeof(*imon), GFP_KERNEL);
123 if (!imon)
124 return -ENOMEM;
125
126 imon->ir_urb = usb_alloc_urb(0, GFP_KERNEL);
127 if (!imon->ir_urb)
128 return -ENOMEM;
129
130 imon->dev = &intf->dev;
131 usb_fill_int_urb(imon->ir_urb, udev,
132 usb_rcvintpipe(udev, ir_ep->bEndpointAddress),
133 imon->ir_buf, sizeof(imon->ir_buf),
134 imon_ir_rx, imon, ir_ep->bInterval);
135
136 rcdev = devm_rc_allocate_device(&intf->dev, RC_DRIVER_IR_RAW);
137 if (!rcdev) {
138 ret = -ENOMEM;
139 goto free_urb;
140 }
141
142 usb_make_path(udev, imon->phys, sizeof(imon->phys));
143
144 rcdev->device_name = "iMON Station";
145 rcdev->driver_name = KBUILD_MODNAME;
146 rcdev->input_phys = imon->phys;
147 usb_to_input_id(udev, &rcdev->input_id);
148 rcdev->dev.parent = &intf->dev;
149 rcdev->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
150 rcdev->map_name = RC_MAP_IMON_RSC;
151 rcdev->rx_resolution = BIT_DURATION;
152 rcdev->priv = imon;
153
154 ret = devm_rc_register_device(&intf->dev, rcdev);
155 if (ret)
156 goto free_urb;
157
158 imon->rcdev = rcdev;
159
160 ret = usb_submit_urb(imon->ir_urb, GFP_KERNEL);
161 if (ret)
162 goto free_urb;
163
164 usb_set_intfdata(intf, imon);
165
166 return 0;
167
168 free_urb:
169 usb_free_urb(imon->ir_urb);
170 return ret;
171 }
172
imon_disconnect(struct usb_interface * intf)173 static void imon_disconnect(struct usb_interface *intf)
174 {
175 struct imon *imon = usb_get_intfdata(intf);
176
177 usb_kill_urb(imon->ir_urb);
178 usb_free_urb(imon->ir_urb);
179 }
180
181 static const struct usb_device_id imon_table[] = {
182 /* SoundGraph iMON (IR only) -- sg_imon.inf */
183 { USB_DEVICE(0x04e8, 0xff30) },
184 {}
185 };
186
187 static struct usb_driver imon_driver = {
188 .name = KBUILD_MODNAME,
189 .probe = imon_probe,
190 .disconnect = imon_disconnect,
191 .id_table = imon_table
192 };
193
194 module_usb_driver(imon_driver);
195
196 MODULE_DESCRIPTION("Early raw iMON IR devices");
197 MODULE_AUTHOR("Sean Young <sean@mess.org>");
198 MODULE_LICENSE("GPL");
199 MODULE_DEVICE_TABLE(usb, imon_table);
200