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 250 |
12 | |
13 | struct imon { |
14 | struct device *dev; |
15 | struct urb *ir_urb; |
16 | struct rc_dev *rcdev; |
17 | __be64 *ir_buf; |
18 | char phys[64]; |
19 | }; |
20 | |
21 | /* |
22 | * The first 5 bytes of data represent IR pulse or space. Each bit, starting |
23 | * from highest bit in the first byte, represents 250µs of data. It is 1 |
24 | * for space and 0 for pulse. |
25 | * |
26 | * The station sends 10 packets, and the 7th byte will be number 1 to 10, so |
27 | * when we receive 10 we assume all the data has arrived. |
28 | */ |
29 | static void imon_ir_data(struct imon *imon) |
30 | { |
31 | struct ir_raw_event rawir = {}; |
32 | u64 data = be64_to_cpup(p: imon->ir_buf); |
33 | u8 packet_no = data & 0xff; |
34 | int offset = 40; |
35 | int bit; |
36 | |
37 | if (packet_no == 0xff) |
38 | return; |
39 | |
40 | dev_dbg(imon->dev, "data: %*ph" , 8, imon->ir_buf); |
41 | |
42 | /* |
43 | * Only the first 5 bytes contain IR data. Right shift so we move |
44 | * the IR bits to the lower 40 bits. |
45 | */ |
46 | data >>= 24; |
47 | |
48 | do { |
49 | /* |
50 | * Find highest set bit which is less or equal to offset |
51 | * |
52 | * offset is the bit above (base 0) where we start looking. |
53 | * |
54 | * data & (BIT_ULL(offset) - 1) masks off any unwanted bits, |
55 | * so we have just bits less than offset. |
56 | * |
57 | * fls will tell us the highest bit set plus 1 (or 0 if no |
58 | * bits are set). |
59 | */ |
60 | rawir.pulse = !rawir.pulse; |
61 | bit = fls64(x: data & (BIT_ULL(offset) - 1)); |
62 | if (bit < offset) { |
63 | dev_dbg(imon->dev, "%s: %d bits" , |
64 | rawir.pulse ? "pulse" : "space" , offset - bit); |
65 | rawir.duration = (offset - bit) * BIT_DURATION; |
66 | ir_raw_event_store_with_filter(dev: imon->rcdev, ev: &rawir); |
67 | |
68 | offset = bit; |
69 | } |
70 | |
71 | data = ~data; |
72 | } while (offset > 0); |
73 | |
74 | if (packet_no == 0x0a && !imon->rcdev->idle) { |
75 | ir_raw_event_set_idle(dev: imon->rcdev, idle: true); |
76 | ir_raw_event_handle(dev: imon->rcdev); |
77 | } |
78 | } |
79 | |
80 | static void imon_ir_rx(struct urb *urb) |
81 | { |
82 | struct imon *imon = urb->context; |
83 | int ret; |
84 | |
85 | switch (urb->status) { |
86 | case 0: |
87 | imon_ir_data(imon); |
88 | break; |
89 | case -ECONNRESET: |
90 | case -ENOENT: |
91 | case -ESHUTDOWN: |
92 | usb_unlink_urb(urb); |
93 | return; |
94 | case -EPIPE: |
95 | default: |
96 | dev_dbg(imon->dev, "error: urb status = %d" , urb->status); |
97 | break; |
98 | } |
99 | |
100 | ret = usb_submit_urb(urb, GFP_ATOMIC); |
101 | if (ret && ret != -ENODEV) |
102 | dev_warn(imon->dev, "failed to resubmit urb: %d" , ret); |
103 | } |
104 | |
105 | static int imon_probe(struct usb_interface *intf, |
106 | const struct usb_device_id *id) |
107 | { |
108 | struct usb_endpoint_descriptor *ir_ep = NULL; |
109 | struct usb_host_interface *idesc; |
110 | struct usb_device *udev; |
111 | struct rc_dev *rcdev; |
112 | struct imon *imon; |
113 | int i, ret; |
114 | |
115 | udev = interface_to_usbdev(intf); |
116 | idesc = intf->cur_altsetting; |
117 | |
118 | for (i = 0; i < idesc->desc.bNumEndpoints; i++) { |
119 | struct usb_endpoint_descriptor *ep = &idesc->endpoint[i].desc; |
120 | |
121 | if (usb_endpoint_is_int_in(epd: ep)) { |
122 | ir_ep = ep; |
123 | break; |
124 | } |
125 | } |
126 | |
127 | if (!ir_ep) { |
128 | dev_err(&intf->dev, "IR endpoint missing" ); |
129 | return -ENODEV; |
130 | } |
131 | |
132 | imon = devm_kmalloc(dev: &intf->dev, size: sizeof(*imon), GFP_KERNEL); |
133 | if (!imon) |
134 | return -ENOMEM; |
135 | |
136 | imon->ir_urb = usb_alloc_urb(iso_packets: 0, GFP_KERNEL); |
137 | if (!imon->ir_urb) |
138 | return -ENOMEM; |
139 | |
140 | imon->ir_buf = kmalloc(size: sizeof(__be64), GFP_KERNEL); |
141 | if (!imon->ir_buf) { |
142 | ret = -ENOMEM; |
143 | goto free_urb; |
144 | } |
145 | |
146 | imon->dev = &intf->dev; |
147 | usb_fill_int_urb(urb: imon->ir_urb, dev: udev, |
148 | usb_rcvintpipe(udev, ir_ep->bEndpointAddress), |
149 | transfer_buffer: imon->ir_buf, buffer_length: sizeof(__be64), |
150 | complete_fn: imon_ir_rx, context: imon, interval: ir_ep->bInterval); |
151 | |
152 | rcdev = devm_rc_allocate_device(dev: &intf->dev, RC_DRIVER_IR_RAW); |
153 | if (!rcdev) { |
154 | ret = -ENOMEM; |
155 | goto free_urb; |
156 | } |
157 | |
158 | usb_make_path(dev: udev, buf: imon->phys, size: sizeof(imon->phys)); |
159 | |
160 | rcdev->device_name = "iMON Station" ; |
161 | rcdev->driver_name = KBUILD_MODNAME; |
162 | rcdev->input_phys = imon->phys; |
163 | usb_to_input_id(dev: udev, id: &rcdev->input_id); |
164 | rcdev->dev.parent = &intf->dev; |
165 | rcdev->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER; |
166 | rcdev->map_name = RC_MAP_IMON_RSC; |
167 | rcdev->rx_resolution = BIT_DURATION; |
168 | rcdev->priv = imon; |
169 | |
170 | ret = devm_rc_register_device(parent: &intf->dev, dev: rcdev); |
171 | if (ret) |
172 | goto free_urb; |
173 | |
174 | imon->rcdev = rcdev; |
175 | |
176 | ret = usb_submit_urb(urb: imon->ir_urb, GFP_KERNEL); |
177 | if (ret) |
178 | goto free_urb; |
179 | |
180 | usb_set_intfdata(intf, data: imon); |
181 | |
182 | return 0; |
183 | |
184 | free_urb: |
185 | usb_free_urb(urb: imon->ir_urb); |
186 | kfree(objp: imon->ir_buf); |
187 | return ret; |
188 | } |
189 | |
190 | static void imon_disconnect(struct usb_interface *intf) |
191 | { |
192 | struct imon *imon = usb_get_intfdata(intf); |
193 | |
194 | usb_kill_urb(urb: imon->ir_urb); |
195 | usb_free_urb(urb: imon->ir_urb); |
196 | kfree(objp: imon->ir_buf); |
197 | } |
198 | |
199 | static const struct usb_device_id imon_table[] = { |
200 | /* SoundGraph iMON (IR only) -- sg_imon.inf */ |
201 | { USB_DEVICE(0x04e8, 0xff30) }, |
202 | {} |
203 | }; |
204 | |
205 | static struct usb_driver imon_driver = { |
206 | .name = KBUILD_MODNAME, |
207 | .probe = imon_probe, |
208 | .disconnect = imon_disconnect, |
209 | .id_table = imon_table |
210 | }; |
211 | |
212 | module_usb_driver(imon_driver); |
213 | |
214 | MODULE_DESCRIPTION("Early raw iMON IR devices" ); |
215 | MODULE_AUTHOR("Sean Young <sean@mess.org>" ); |
216 | MODULE_LICENSE("GPL" ); |
217 | MODULE_DEVICE_TABLE(usb, imon_table); |
218 | |