benq.c

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/*
 * Benq DC E300 subdriver
 *
 * Copyright (C) 2009 Jean-Francois Moine (http://moinejf.free.fr)
 *
 * 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
 * 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
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#define MODULE_NAME "benq"

#include "gspca.h"

MODULE_AUTHOR("Jean-Francois Moine <http://moinejf.free.fr>");
MODULE_DESCRIPTION("Benq DC E300 USB Camera Driver");
MODULE_LICENSE("GPL");

/* specific webcam descriptor */
struct sd {
    struct gspca_dev gspca_dev; /* !! must be the first item */
};

static const struct v4l2_pix_format vga_mode[] = {
    {320, 240, V4L2_PIX_FMT_JPEG, V4L2_FIELD_NONE,
        .bytesperline = 320,
        .sizeimage = 320 * 240 * 3 / 8 + 590,
        .colorspace = V4L2_COLORSPACE_JPEG},
};

static void sd_isoc_irq(struct urb *urb);

/* -- write a register -- */
static void reg_w(struct gspca_dev *gspca_dev,
            u16 value, u16 index)
{
    struct usb_device *dev = gspca_dev->dev;
    int ret;

    if (gspca_dev->usb_err < 0)
        return;
    ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
            0x02,
            USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
            value,
            index,
            NULL,
            0,
            500);
    if (ret < 0) {
        pr_err("reg_w err %d\n", ret);
        gspca_dev->usb_err = ret;
    }
}

/* this function is called at probe time */
static int sd_config(struct gspca_dev *gspca_dev,
            const struct usb_device_id *id)
{
    gspca_dev->cam.cam_mode = vga_mode;
    gspca_dev->cam.nmodes = ARRAY_SIZE(vga_mode);
    gspca_dev->cam.no_urb_create = 1;
    return 0;
}

/* this function is called at probe and resume time */
static int sd_init(struct gspca_dev *gspca_dev)
{
    return 0;
}

/* -- start the camera -- */
static int sd_start(struct gspca_dev *gspca_dev)
{
    struct urb *urb;
    int i, n;

    /* create 4 URBs - 2 on endpoint 0x83 and 2 on 0x082 */
#if MAX_NURBS < 4
#error "Not enough URBs in the gspca table"
#endif
#define SD_PKT_SZ 64
#define SD_NPKT 32
    for (n = 0; n < 4; n++) {
        urb = usb_alloc_urb(SD_NPKT, GFP_KERNEL);
        if (!urb) {
            pr_err("usb_alloc_urb failed\n");
            return -ENOMEM;
        }
        gspca_dev->urb[n] = urb;
        urb->transfer_buffer = usb_alloc_coherent(gspca_dev->dev,
                        SD_PKT_SZ * SD_NPKT,
                        GFP_KERNEL,
                        &urb->transfer_dma);

        if (urb->transfer_buffer == NULL) {
            pr_err("usb_alloc_coherent failed\n");
            return -ENOMEM;
        }
        urb->dev = gspca_dev->dev;
        urb->context = gspca_dev;
        urb->transfer_buffer_length = SD_PKT_SZ * SD_NPKT;
        urb->pipe = usb_rcvisocpipe(gspca_dev->dev,
                    n & 1 ? 0x82 : 0x83);
        urb->transfer_flags = URB_ISO_ASAP
                    | URB_NO_TRANSFER_DMA_MAP;
        urb->interval = 1;
        urb->complete = sd_isoc_irq;
        urb->number_of_packets = SD_NPKT;
        for (i = 0; i < SD_NPKT; i++) {
            urb->iso_frame_desc[i].length = SD_PKT_SZ;
            urb->iso_frame_desc[i].offset = SD_PKT_SZ * i;
        }
    }

    return gspca_dev->usb_err;
}

static void sd_stopN(struct gspca_dev *gspca_dev)
{
    struct usb_interface *intf;

    reg_w(gspca_dev, 0x003c, 0x0003);
    reg_w(gspca_dev, 0x003c, 0x0004);
    reg_w(gspca_dev, 0x003c, 0x0005);
    reg_w(gspca_dev, 0x003c, 0x0006);
    reg_w(gspca_dev, 0x003c, 0x0007);

    intf = usb_ifnum_to_if(gspca_dev->dev, gspca_dev->iface);
    usb_set_interface(gspca_dev->dev, gspca_dev->iface,
                    intf->num_altsetting - 1);
}

static void sd_pkt_scan(struct gspca_dev *gspca_dev,
            u8 *data,       /* isoc packet */
            int len)        /* iso packet length */
{
    /* unused */
}

/* reception of an URB */
static void sd_isoc_irq(struct urb *urb)
{
    struct gspca_dev *gspca_dev = (struct gspca_dev *) urb->context;
    struct urb *urb0;
    u8 *data;
    int i, st;

    PDEBUG(D_PACK, "sd isoc irq");
    if (!gspca_dev->streaming)
        return;
    if (urb->status != 0) {
        if (urb->status == -ESHUTDOWN)
            return;     /* disconnection */
#ifdef CONFIG_PM
        if (gspca_dev->frozen)
            return;
#endif
        pr_err("urb status: %d\n", urb->status);
        return;
    }

    /* if this is a control URN (ep 0x83), wait */
    if (urb == gspca_dev->urb[0] || urb == gspca_dev->urb[2])
        return;

    /* scan both received URBs */
    if (urb == gspca_dev->urb[1])
        urb0 = gspca_dev->urb[0];
    else
        urb0 = gspca_dev->urb[2];
    for (i = 0; i < urb->number_of_packets; i++) {

        /* check the packet status and length */
        if (urb0->iso_frame_desc[i].actual_length != SD_PKT_SZ
            || urb->iso_frame_desc[i].actual_length != SD_PKT_SZ) {
            PDEBUG(D_ERR, "ISOC bad lengths %d / %d",
                urb0->iso_frame_desc[i].actual_length,
                urb->iso_frame_desc[i].actual_length);
            gspca_dev->last_packet_type = DISCARD_PACKET;
            continue;
        }
        st = urb0->iso_frame_desc[i].status;
        if (st == 0)
            st = urb->iso_frame_desc[i].status;
        if (st) {
            pr_err("ISOC data error: [%d] status=%d\n",
                i, st);
            gspca_dev->last_packet_type = DISCARD_PACKET;
            continue;
        }

        /*
         * The images are received in URBs of different endpoints
         * (0x83 and 0x82).
         * Image pieces in URBs of ep 0x83 are continuated in URBs of
         * ep 0x82 of the same index.
         * The packets in the URBs of endpoint 0x83 start with:
         *  - 80 ba/bb 00 00 = start of image followed by 'ff d8'
         *  - 04 ba/bb oo oo = image piece
         *      where 'oo oo' is the image offset
                        (not cheked)
         *  - (other -> bad frame)
         * The images are JPEG encoded with full header and
         * normal ff escape.
         * The end of image ('ff d9') may occur in any URB.
         * (not cheked)
         */
        data = (u8 *) urb0->transfer_buffer
                    + urb0->iso_frame_desc[i].offset;
        if (data[0] == 0x80 && (data[1] & 0xfe) == 0xba) {

            /* new image */
            gspca_frame_add(gspca_dev, LAST_PACKET,
                    NULL, 0);
            gspca_frame_add(gspca_dev, FIRST_PACKET,
                    data + 4, SD_PKT_SZ - 4);
        } else if (data[0] == 0x04 && (data[1] & 0xfe) == 0xba) {
            gspca_frame_add(gspca_dev, INTER_PACKET,
                    data + 4, SD_PKT_SZ - 4);
        } else {
            gspca_dev->last_packet_type = DISCARD_PACKET;
            continue;
        }
        data = (u8 *) urb->transfer_buffer
                    + urb->iso_frame_desc[i].offset;
            gspca_frame_add(gspca_dev, INTER_PACKET,
                    data, SD_PKT_SZ);
    }

    /* resubmit the URBs */
    st = usb_submit_urb(urb0, GFP_ATOMIC);
    if (st < 0)
        pr_err("usb_submit_urb(0) ret %d\n", st);
    st = usb_submit_urb(urb, GFP_ATOMIC);
    if (st < 0)
        pr_err("usb_submit_urb() ret %d\n", st);
}

/* sub-driver description */
static const struct sd_desc sd_desc = {
    .name = MODULE_NAME,
    .config = sd_config,
    .init = sd_init,
    .start = sd_start,
    .stopN = sd_stopN,
    .pkt_scan = sd_pkt_scan,
};

/* -- module initialisation -- */
static const struct usb_device_id device_table[] = {
    {USB_DEVICE(0x04a5, 0x3035)},
    {}
};
MODULE_DEVICE_TABLE(usb, device_table);

/* -- device connect -- */
static int sd_probe(struct usb_interface *intf,
            const struct usb_device_id *id)
{
    return gspca_dev_probe(intf, id, &sd_desc, sizeof(struct sd),
                THIS_MODULE);
}

static struct usb_driver sd_driver = {
    .name = MODULE_NAME,
    .id_table = device_table,
    .probe = sd_probe,
    .disconnect = gspca_disconnect,
#ifdef CONFIG_PM
    .suspend = gspca_suspend,
    .resume = gspca_resume,
    .reset_resume = gspca_resume,
#endif
};

module_usb_driver(sd_driver);