linux/drivers/media/rc/imon_raw.c
Sean Young 8d023a5787 media: rc: imon_raw: use fls rather than loop per bit
Previously, the code would loop for each of the 40 bits. Now it will
branch for each edge in the IR, which will be much less.

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-11-22 13:29:27 -05:00

199 lines
4.4 KiB
C

// 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);