1 // SPDX-License-Identifier: GPL-2.0+
3 // Copyright (C) 2018 Sean Young <sean@mess.org>
5 #include <linux/module.h>
7 #include <linux/usb/input.h>
8 #include <media/rc-core.h>
10 /* Each bit is 250us */
11 #define BIT_DURATION 250000
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.
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.
29 static void imon_ir_data(struct imon *imon)
31 struct ir_raw_event rawir = {};
32 u64 data = be64_to_cpu(imon->ir_buf);
33 u8 packet_no = data & 0xff;
37 if (packet_no == 0xff)
40 dev_dbg(imon->dev, "data: %*ph", 8, &imon->ir_buf);
43 * Only the first 5 bytes contain IR data. Right shift so we move
44 * the IR bits to the lower 40 bits.
50 * Find highest set bit which is less or equal to offset
52 * offset is the bit above (base 0) where we start looking.
54 * data & (BIT_ULL(offset) - 1) masks off any unwanted bits,
55 * so we have just bits less than offset.
57 * fls will tell us the highest bit set plus 1 (or 0 if no
60 bit = fls64(data & (BIT_ULL(offset) - 1));
62 dev_dbg(imon->dev, "pulse: %d bits", offset - bit);
64 rawir.duration = (offset - bit) * BIT_DURATION;
65 ir_raw_event_store_with_filter(imon->rcdev, &rawir);
74 * Find highest clear bit which is less than offset.
76 * Just invert the data and use same trick as above.
78 bit = fls64(~data & (BIT_ULL(offset) - 1));
79 dev_dbg(imon->dev, "space: %d bits", offset - bit);
82 rawir.duration = (offset - bit) * BIT_DURATION;
83 ir_raw_event_store_with_filter(imon->rcdev, &rawir);
88 if (packet_no == 0x0a && !imon->rcdev->idle) {
89 ir_raw_event_set_idle(imon->rcdev, true);
90 ir_raw_event_handle(imon->rcdev);
94 static void imon_ir_rx(struct urb *urb)
96 struct imon *imon = urb->context;
99 switch (urb->status) {
110 dev_dbg(imon->dev, "error: urb status = %d", urb->status);
114 ret = usb_submit_urb(urb, GFP_ATOMIC);
115 if (ret && ret != -ENODEV)
116 dev_warn(imon->dev, "failed to resubmit urb: %d", ret);
119 static int imon_probe(struct usb_interface *intf,
120 const struct usb_device_id *id)
122 struct usb_endpoint_descriptor *ir_ep = NULL;
123 struct usb_host_interface *idesc;
124 struct usb_device *udev;
125 struct rc_dev *rcdev;
129 udev = interface_to_usbdev(intf);
130 idesc = intf->cur_altsetting;
132 for (i = 0; i < idesc->desc.bNumEndpoints; i++) {
133 struct usb_endpoint_descriptor *ep = &idesc->endpoint[i].desc;
135 if (usb_endpoint_is_int_in(ep)) {
142 dev_err(&intf->dev, "IR endpoint missing");
146 imon = devm_kmalloc(&intf->dev, sizeof(*imon), GFP_KERNEL);
150 imon->ir_urb = usb_alloc_urb(0, GFP_KERNEL);
154 imon->dev = &intf->dev;
155 usb_fill_int_urb(imon->ir_urb, udev,
156 usb_rcvintpipe(udev, ir_ep->bEndpointAddress),
157 &imon->ir_buf, sizeof(imon->ir_buf),
158 imon_ir_rx, imon, ir_ep->bInterval);
160 rcdev = devm_rc_allocate_device(&intf->dev, RC_DRIVER_IR_RAW);
166 usb_make_path(udev, imon->phys, sizeof(imon->phys));
168 rcdev->device_name = "iMON Station";
169 rcdev->driver_name = KBUILD_MODNAME;
170 rcdev->input_phys = imon->phys;
171 usb_to_input_id(udev, &rcdev->input_id);
172 rcdev->dev.parent = &intf->dev;
173 rcdev->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
174 rcdev->map_name = RC_MAP_IMON_RSC;
175 rcdev->rx_resolution = BIT_DURATION;
178 ret = devm_rc_register_device(&intf->dev, rcdev);
184 ret = usb_submit_urb(imon->ir_urb, GFP_KERNEL);
188 usb_set_intfdata(intf, imon);
193 usb_free_urb(imon->ir_urb);
197 static void imon_disconnect(struct usb_interface *intf)
199 struct imon *imon = usb_get_intfdata(intf);
201 usb_kill_urb(imon->ir_urb);
202 usb_free_urb(imon->ir_urb);
205 static const struct usb_device_id imon_table[] = {
206 /* SoundGraph iMON (IR only) -- sg_imon.inf */
207 { USB_DEVICE(0x04e8, 0xff30) },
211 static struct usb_driver imon_driver = {
212 .name = KBUILD_MODNAME,
214 .disconnect = imon_disconnect,
215 .id_table = imon_table
218 module_usb_driver(imon_driver);
220 MODULE_DESCRIPTION("Early raw iMON IR devices");
221 MODULE_AUTHOR("Sean Young <sean@mess.org>");
222 MODULE_LICENSE("GPL");
223 MODULE_DEVICE_TABLE(usb, imon_table);