ttusbir.c

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/*
 * TechnoTrend USB IR Receiver
 *
 * Copyright (C) 2012 Sean Young <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <linux/module.h>
#include <linux/usb.h>
#include <linux/usb/input.h>
#include <linux/slab.h>
#include <linux/leds.h>
#include <media/rc-core.h>

#define DRIVER_NAME "ttusbir"
#define DRIVER_DESC "TechnoTrend USB IR Receiver"
/*
 * The Windows driver uses 8 URBS, the original lirc drivers has a
 * configurable amount (2 default, 4 max). This device generates about 125
 * messages per second (!), whether IR is idle or not.
 */
#define NUM_URBS    4
#define NS_PER_BYTE 62500
#define NS_PER_BIT  (NS_PER_BYTE/8)

struct ttusbir {
    struct rc_dev *rc;
    struct device *dev;
    struct usb_device *udev;

    struct urb *urb[NUM_URBS];

    struct led_classdev led;
    struct urb *bulk_urb;
    uint8_t bulk_buffer[5];
    int bulk_out_endp, iso_in_endp;
    bool led_on, is_led_on;
    atomic_t led_complete;

    char phys[64];
};

static enum led_brightness ttusbir_brightness_get(struct led_classdev *led_dev)
{
    struct ttusbir *tt = container_of(led_dev, struct ttusbir, led);

    return tt->led_on ? LED_FULL : LED_OFF;
}

static void ttusbir_set_led(struct ttusbir *tt)
{
    int ret;

    smp_mb();

    if (tt->led_on != tt->is_led_on && tt->udev &&
                atomic_add_unless(&tt->led_complete, 1, 1)) {
        tt->bulk_buffer[4] = tt->is_led_on = tt->led_on;
        ret = usb_submit_urb(tt->bulk_urb, GFP_ATOMIC);
        if (ret) {
            dev_warn(tt->dev, "failed to submit bulk urb: %d\n",
                                    ret);
            atomic_dec(&tt->led_complete);
        }
    }
}

static void ttusbir_brightness_set(struct led_classdev *led_dev, enum
                        led_brightness brightness)
{
    struct ttusbir *tt = container_of(led_dev, struct ttusbir, led);

    tt->led_on = brightness != LED_OFF;

    ttusbir_set_led(tt);
}

/*
 * The urb cannot be reused until the urb completes
 */
static void ttusbir_bulk_complete(struct urb *urb)
{
    struct ttusbir *tt = urb->context;

    atomic_dec(&tt->led_complete);

    switch (urb->status) {
    case 0:
        break;
    case -ECONNRESET:
    case -ENOENT:
    case -ESHUTDOWN:
        usb_unlink_urb(urb);
        return;
    case -EPIPE:
    default:
        dev_dbg(tt->dev, "Error: urb status = %d\n", urb->status);
        break;
    }

    ttusbir_set_led(tt);
}

/*
 * The data is one bit per sample, a set bit signifying silence and samples
 * being MSB first. Bit 0 can contain garbage so take it to be whatever
 * bit 1 is, so we don't have unexpected edges.
 */
static void ttusbir_process_ir_data(struct ttusbir *tt, uint8_t *buf)
{
    struct ir_raw_event rawir;
    unsigned i, v, b;
    bool event = false;

    init_ir_raw_event(&rawir);

    for (i = 0; i < 128; i++) {
        v = buf[i] & 0xfe;
        switch (v) {
        case 0xfe:
            rawir.pulse = false;
            rawir.duration = NS_PER_BYTE;
            if (ir_raw_event_store_with_filter(tt->rc, &rawir))
                event = true;
            break;
        case 0:
            rawir.pulse = true;
            rawir.duration = NS_PER_BYTE;
            if (ir_raw_event_store_with_filter(tt->rc, &rawir))
                event = true;
            break;
        default:
            /* one edge per byte */
            if (v & 2) {
                b = ffz(v | 1);
                rawir.pulse = true;
            } else {
                b = ffs(v) - 1;
                rawir.pulse = false;
            }

            rawir.duration = NS_PER_BIT * (8 - b);
            if (ir_raw_event_store_with_filter(tt->rc, &rawir))
                event = true;

            rawir.pulse = !rawir.pulse;
            rawir.duration = NS_PER_BIT * b;
            if (ir_raw_event_store_with_filter(tt->rc, &rawir))
                event = true;
            break;
        }
    }

    /* don't wakeup when there's nothing to do */
    if (event)
        ir_raw_event_handle(tt->rc);
}

static void ttusbir_urb_complete(struct urb *urb)
{
    struct ttusbir *tt = urb->context;
    int rc;

    switch (urb->status) {
    case 0:
        ttusbir_process_ir_data(tt, urb->transfer_buffer);
        break;
    case -ECONNRESET:
    case -ENOENT:
    case -ESHUTDOWN:
        usb_unlink_urb(urb);
        return;
    case -EPIPE:
    default:
        dev_dbg(tt->dev, "Error: urb status = %d\n", urb->status);
        break;
    }

    rc = usb_submit_urb(urb, GFP_ATOMIC);
    if (rc && rc != -ENODEV)
        dev_warn(tt->dev, "failed to resubmit urb: %d\n", rc);
}

static int __devinit ttusbir_probe(struct usb_interface *intf,
                        const struct usb_device_id *id)
{
    struct ttusbir *tt;
    struct usb_interface_descriptor *idesc;
    struct usb_endpoint_descriptor *desc;
    struct rc_dev *rc;
    int i, j, ret;
    int altsetting = -1;

    tt = kzalloc(sizeof(*tt), GFP_KERNEL);
    rc = rc_allocate_device();
    if (!tt || !rc) {
        ret = -ENOMEM;
        goto out;
    }

    /* find the correct alt setting */
    for (i = 0; i < intf->num_altsetting && altsetting == -1; i++) {
        int bulk_out_endp = -1, iso_in_endp = -1;

        idesc = &intf->altsetting[i].desc;

        for (j = 0; j < idesc->bNumEndpoints; j++) {
            desc = &intf->altsetting[i].endpoint[j].desc;
            if (usb_endpoint_dir_in(desc) &&
                    usb_endpoint_xfer_isoc(desc) &&
                    desc->wMaxPacketSize == 0x10)
                iso_in_endp = j;
            else if (usb_endpoint_dir_out(desc) &&
                    usb_endpoint_xfer_bulk(desc) &&
                    desc->wMaxPacketSize == 0x20)
                bulk_out_endp = j;

            if (bulk_out_endp != -1 && iso_in_endp != -1) {
                tt->bulk_out_endp = bulk_out_endp;
                tt->iso_in_endp = iso_in_endp;
                altsetting = i;
                break;
            }
        }
    }

    if (altsetting == -1) {
        dev_err(&intf->dev, "cannot find expected altsetting\n");
        ret = -ENODEV;
        goto out;
    }

    tt->dev = &intf->dev;
    tt->udev = interface_to_usbdev(intf);
    tt->rc = rc;

    ret = usb_set_interface(tt->udev, 0, altsetting);
    if (ret)
        goto out;

    for (i = 0; i < NUM_URBS; i++) {
        struct urb *urb = usb_alloc_urb(8, GFP_KERNEL);
        void *buffer;

        if (!urb) {
            ret = -ENOMEM;
            goto out;
        }

        urb->dev = tt->udev;
        urb->context = tt;
        urb->pipe = usb_rcvisocpipe(tt->udev, tt->iso_in_endp);
        urb->interval = 1;
        buffer = usb_alloc_coherent(tt->udev, 128, GFP_KERNEL,
                        &urb->transfer_dma);
        if (!buffer) {
            usb_free_urb(urb);
            ret = -ENOMEM;
            goto out;
        }
        urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP | URB_ISO_ASAP;
        urb->transfer_buffer = buffer;
        urb->complete = ttusbir_urb_complete;
        urb->number_of_packets = 8;
        urb->transfer_buffer_length = 128;

        for (j = 0; j < 8; j++) {
            urb->iso_frame_desc[j].offset = j * 16;
            urb->iso_frame_desc[j].length = 16;
        }

        tt->urb[i] = urb;
    }

    tt->bulk_urb = usb_alloc_urb(0, GFP_KERNEL);
    if (!tt->bulk_urb) {
        ret = -ENOMEM;
        goto out;
    }

    tt->bulk_buffer[0] = 0xaa;
    tt->bulk_buffer[1] = 0x01;
    tt->bulk_buffer[2] = 0x05;
    tt->bulk_buffer[3] = 0x01;

    usb_fill_bulk_urb(tt->bulk_urb, tt->udev, usb_sndbulkpipe(tt->udev,
        tt->bulk_out_endp), tt->bulk_buffer, sizeof(tt->bulk_buffer),
                        ttusbir_bulk_complete, tt);

    tt->led.name = "ttusbir:green:power";
    tt->led.brightness_set = ttusbir_brightness_set;
    tt->led.brightness_get = ttusbir_brightness_get;
    tt->is_led_on = tt->led_on = true;
    atomic_set(&tt->led_complete, 0);
    ret = led_classdev_register(&intf->dev, &tt->led);
    if (ret)
        goto out;

    usb_make_path(tt->udev, tt->phys, sizeof(tt->phys));

    rc->input_name = DRIVER_DESC;
    rc->input_phys = tt->phys;
    usb_to_input_id(tt->udev, &rc->input_id);
    rc->dev.parent = &intf->dev;
    rc->driver_type = RC_DRIVER_IR_RAW;
    rc->allowed_protos = RC_TYPE_ALL;
    rc->priv = tt;
    rc->driver_name = DRIVER_NAME;
    rc->map_name = RC_MAP_TT_1500;
    rc->timeout = MS_TO_NS(100);
    /*
     * The precision is NS_PER_BIT, but since every 8th bit can be
     * overwritten with garbage the accuracy is at best 2 * NS_PER_BIT.
     */
    rc->rx_resolution = NS_PER_BIT;

    ret = rc_register_device(rc);
    if (ret) {
        dev_err(&intf->dev, "failed to register rc device %d\n", ret);
        goto out2;
    }

    usb_set_intfdata(intf, tt);

    for (i = 0; i < NUM_URBS; i++) {
        ret = usb_submit_urb(tt->urb[i], GFP_KERNEL);
        if (ret) {
            dev_err(tt->dev, "failed to submit urb %d\n", ret);
            goto out3;
        }
    }

    return 0;
out3:
    rc_unregister_device(rc);
out2:
    led_classdev_unregister(&tt->led);
out:
    if (tt) {
        for (i = 0; i < NUM_URBS && tt->urb[i]; i++) {
            struct urb *urb = tt->urb[i];

            usb_kill_urb(urb);
            usb_free_coherent(tt->udev, 128, urb->transfer_buffer,
                            urb->transfer_dma);
            usb_free_urb(urb);
        }
        usb_kill_urb(tt->bulk_urb);
        usb_free_urb(tt->bulk_urb);
        kfree(tt);
    }
    rc_free_device(rc);

    return ret;
}

static void __devexit ttusbir_disconnect(struct usb_interface *intf)
{
    struct ttusbir *tt = usb_get_intfdata(intf);
    struct usb_device *udev = tt->udev;
    int i;

    tt->udev = NULL;

    rc_unregister_device(tt->rc);
    led_classdev_unregister(&tt->led);
    for (i = 0; i < NUM_URBS; i++) {
        usb_kill_urb(tt->urb[i]);
        usb_free_coherent(udev, 128, tt->urb[i]->transfer_buffer,
                        tt->urb[i]->transfer_dma);
        usb_free_urb(tt->urb[i]);
    }
    usb_kill_urb(tt->bulk_urb);
    usb_free_urb(tt->bulk_urb);
    usb_set_intfdata(intf, NULL);
    kfree(tt);
}

static int ttusbir_suspend(struct usb_interface *intf, pm_message_t message)
{
    struct ttusbir *tt = usb_get_intfdata(intf);
    int i;

    for (i = 0; i < NUM_URBS; i++)
        usb_kill_urb(tt->urb[i]);

    led_classdev_suspend(&tt->led);
    usb_kill_urb(tt->bulk_urb);

    return 0;
}

static int ttusbir_resume(struct usb_interface *intf)
{
    struct ttusbir *tt = usb_get_intfdata(intf);
    int i, rc;

    led_classdev_resume(&tt->led);
    tt->is_led_on = true;
    ttusbir_set_led(tt);

    for (i = 0; i < NUM_URBS; i++) {
        rc = usb_submit_urb(tt->urb[i], GFP_KERNEL);
        if (rc) {
            dev_warn(tt->dev, "failed to submit urb: %d\n", rc);
            break;
        }
    }

    return rc;
}

static const struct usb_device_id ttusbir_table[] = {
    { USB_DEVICE(0x0b48, 0x2003) },
    { }
};

static struct usb_driver ttusbir_driver = {
    .name = DRIVER_NAME,
    .id_table = ttusbir_table,
    .probe = ttusbir_probe,
    .suspend = ttusbir_suspend,
    .resume = ttusbir_resume,
    .reset_resume = ttusbir_resume,
    .disconnect = __devexit_p(ttusbir_disconnect)
};

module_usb_driver(ttusbir_driver);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR("Sean Young <[email protected]>");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(usb, ttusbir_table);