uvc_status.c

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/*
 *      uvc_status.c  --  USB Video Class driver - Status endpoint
 *
 *      Copyright (C) 2005-2009
 *          Laurent Pinchart ([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.
 *
 */

#include <linux/kernel.h>
#include <linux/input.h>
#include <linux/slab.h>
#include <linux/usb.h>
#include <linux/usb/input.h>

#include "uvcvideo.h"

/* --------------------------------------------------------------------------
 * Input device
 */
#ifdef CONFIG_USB_VIDEO_CLASS_INPUT_EVDEV
static int uvc_input_init(struct uvc_device *dev)
{
    struct input_dev *input;
    int ret;

    input = input_allocate_device();
    if (input == NULL)
        return -ENOMEM;

    usb_make_path(dev->udev, dev->input_phys, sizeof(dev->input_phys));
    strlcat(dev->input_phys, "/button", sizeof(dev->input_phys));

    input->name = dev->name;
    input->phys = dev->input_phys;
    usb_to_input_id(dev->udev, &input->id);
    input->dev.parent = &dev->intf->dev;

    __set_bit(EV_KEY, input->evbit);
    __set_bit(KEY_CAMERA, input->keybit);

    if ((ret = input_register_device(input)) < 0)
        goto error;

    dev->input = input;
    return 0;

error:
    input_free_device(input);
    return ret;
}

static void uvc_input_cleanup(struct uvc_device *dev)
{
    if (dev->input)
        input_unregister_device(dev->input);
}

static void uvc_input_report_key(struct uvc_device *dev, unsigned int code,
    int value)
{
    if (dev->input) {
        input_report_key(dev->input, code, value);
        input_sync(dev->input);
    }
}

#else
#define uvc_input_init(dev)
#define uvc_input_cleanup(dev)
#define uvc_input_report_key(dev, code, value)
#endif /* CONFIG_USB_VIDEO_CLASS_INPUT_EVDEV */

/* --------------------------------------------------------------------------
 * Status interrupt endpoint
 */
static void uvc_event_streaming(struct uvc_device *dev, __u8 *data, int len)
{
    if (len < 3) {
        uvc_trace(UVC_TRACE_STATUS, "Invalid streaming status event "
                "received.\n");
        return;
    }

    if (data[2] == 0) {
        if (len < 4)
            return;
        uvc_trace(UVC_TRACE_STATUS, "Button (intf %u) %s len %d\n",
            data[1], data[3] ? "pressed" : "released", len);
        uvc_input_report_key(dev, KEY_CAMERA, data[3]);
    } else {
        uvc_trace(UVC_TRACE_STATUS, "Stream %u error event %02x %02x "
            "len %d.\n", data[1], data[2], data[3], len);
    }
}

static void uvc_event_control(struct uvc_device *dev, __u8 *data, int len)
{
    char *attrs[3] = { "value", "info", "failure" };

    if (len < 6 || data[2] != 0 || data[4] > 2) {
        uvc_trace(UVC_TRACE_STATUS, "Invalid control status event "
                "received.\n");
        return;
    }

    uvc_trace(UVC_TRACE_STATUS, "Control %u/%u %s change len %d.\n",
        data[1], data[3], attrs[data[4]], len);
}

static void uvc_status_complete(struct urb *urb)
{
    struct uvc_device *dev = urb->context;
    int len, ret;

    switch (urb->status) {
    case 0:
        break;

    case -ENOENT:       /* usb_kill_urb() called. */
    case -ECONNRESET:   /* usb_unlink_urb() called. */
    case -ESHUTDOWN:    /* The endpoint is being disabled. */
    case -EPROTO:       /* Device is disconnected (reported by some
                 * host controller). */
        return;

    default:
        uvc_printk(KERN_WARNING, "Non-zero status (%d) in status "
            "completion handler.\n", urb->status);
        return;
    }

    len = urb->actual_length;
    if (len > 0) {
        switch (dev->status[0] & 0x0f) {
        case UVC_STATUS_TYPE_CONTROL:
            uvc_event_control(dev, dev->status, len);
            break;

        case UVC_STATUS_TYPE_STREAMING:
            uvc_event_streaming(dev, dev->status, len);
            break;

        default:
            uvc_trace(UVC_TRACE_STATUS, "Unknown status event "
                "type %u.\n", dev->status[0]);
            break;
        }
    }

    /* Resubmit the URB. */
    urb->interval = dev->int_ep->desc.bInterval;
    if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
        uvc_printk(KERN_ERR, "Failed to resubmit status URB (%d).\n",
            ret);
    }
}

int uvc_status_init(struct uvc_device *dev)
{
    struct usb_host_endpoint *ep = dev->int_ep;
    unsigned int pipe;
    int interval;

    if (ep == NULL)
        return 0;

    uvc_input_init(dev);

    dev->status = kzalloc(UVC_MAX_STATUS_SIZE, GFP_KERNEL);
    if (dev->status == NULL)
        return -ENOMEM;

    dev->int_urb = usb_alloc_urb(0, GFP_KERNEL);
    if (dev->int_urb == NULL) {
        kfree(dev->status);
        return -ENOMEM;
    }

    pipe = usb_rcvintpipe(dev->udev, ep->desc.bEndpointAddress);

    /* For high-speed interrupt endpoints, the bInterval value is used as
     * an exponent of two. Some developers forgot about it.
     */
    interval = ep->desc.bInterval;
    if (interval > 16 && dev->udev->speed == USB_SPEED_HIGH &&
        (dev->quirks & UVC_QUIRK_STATUS_INTERVAL))
        interval = fls(interval) - 1;

    usb_fill_int_urb(dev->int_urb, dev->udev, pipe,
        dev->status, UVC_MAX_STATUS_SIZE, uvc_status_complete,
        dev, interval);

    return 0;
}

void uvc_status_cleanup(struct uvc_device *dev)
{
    usb_kill_urb(dev->int_urb);
    usb_free_urb(dev->int_urb);
    kfree(dev->status);
    uvc_input_cleanup(dev);
}

int uvc_status_start(struct uvc_device *dev)
{
    if (dev->int_urb == NULL)
        return 0;

    return usb_submit_urb(dev->int_urb, GFP_KERNEL);
}

void uvc_status_stop(struct uvc_device *dev)
{
    usb_kill_urb(dev->int_urb);
}

int uvc_status_suspend(struct uvc_device *dev)
{
    if (atomic_read(&dev->users))
        usb_kill_urb(dev->int_urb);

    return 0;
}

int uvc_status_resume(struct uvc_device *dev)
{
    if (dev->int_urb == NULL || atomic_read(&dev->users) == 0)
        return 0;

    return usb_submit_urb(dev->int_urb, GFP_NOIO);
}