Skip to content
Permalink
Branch: master
Find file Copy path
Find file Copy path
Fetching contributors…
Cannot retrieve contributors at this time
224 lines (183 sloc) 5 KB
// 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;
__be64 ir_buf;
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 data = be64_to_cpu(imon->ir_buf);
u8 packet_no = data & 0xff;
int offset = 40;
int bit;
if (packet_no == 0xff)
return;
dev_dbg(imon->dev, "data: %*ph", 8, &imon->ir_buf);
/*
* Only the first 5 bytes contain IR data. Right shift so we move
* the IR bits to the lower 40 bits.
*/
data >>= 24;
do {
/*
* Find highest set bit which is less or equal to offset
*
* offset is the bit above (base 0) where we start looking.
*
* data & (BIT_ULL(offset) - 1) masks off any unwanted bits,
* so we have just bits less than offset.
*
* fls will tell us the highest bit set plus 1 (or 0 if no
* bits are set).
*/
bit = fls64(data & (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;
}
/*
* Find highest clear bit which is less than offset.
*
* Just invert the data and use same trick as above.
*/
bit = fls64(~data & (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 (packet_no == 0x0a && !imon->rcdev->idle) {
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:
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);
You can’t perform that action at this time.