/*
 * Jeilinj subdriver
 *
 * Supports some Jeilin dual-mode cameras which use bulk transport and
 * download raw JPEG data.
 *
 * Copyright (C) 2009 Theodore Kilgore
 *
 * 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 MODULE_NAME "jeilinj"

#include <linux/workqueue.h>
#include "gspca.h"
#include "jpeg.h"

MODULE_AUTHOR("Theodore Kilgore <kilgota@auburn.edu>");
MODULE_DESCRIPTION("GSPCA/JEILINJ USB Camera Driver");
MODULE_LICENSE("GPL");

/* Default timeouts, in ms */
#define JEILINJ_CMD_TIMEOUT 500
#define JEILINJ_DATA_TIMEOUT 1000

/* Maximum transfer size to use. */
#define JEILINJ_MAX_TRANSFER 0x200

#define FRAME_HEADER_LEN 0x10

/* Structure to hold all of our device specific stuff */
struct sd {
        struct gspca_dev gspca_dev;     /* !! must be the first item */
        const struct v4l2_pix_format *cap_mode;
        /* Driver stuff */
        struct work_struct work_struct;
        struct workqueue_struct *work_thread;
        u8 quality;                              /* image quality */
        u8 jpegqual;                            /* webcam quality */
        u8 *jpeg_hdr;
};

        struct jlj_command {
                unsigned char instruction[2];
                unsigned char ack_wanted;
        };

/* AFAICT these cameras will only do 320x240. */
static struct v4l2_pix_format jlj_mode[] = {
        { 320, 240, V4L2_PIX_FMT_JPEG, V4L2_FIELD_NONE,
                .bytesperline = 320,
                .sizeimage = 320 * 240,
                .colorspace = V4L2_COLORSPACE_JPEG,
                .priv = 0}
};

/*
 * cam uses endpoint 0x03 to send commands, 0x84 for read commands,
 * and 0x82 for bulk transfer.
 */

/* All commands are two bytes only */
static int jlj_write2(struct gspca_dev *gspca_dev, unsigned char *command)
{
        int retval;

        memcpy(gspca_dev->usb_buf, command, 2);
        retval = usb_bulk_msg(gspca_dev->dev,
                        usb_sndbulkpipe(gspca_dev->dev, 3),
                        gspca_dev->usb_buf, 2, NULL, 500);
        if (retval < 0)
                PDEBUG(D_ERR, "command write [%02x] error %d",
                                gspca_dev->usb_buf[0], retval);
        return retval;
}

/* Responses are one byte only */
static int jlj_read1(struct gspca_dev *gspca_dev, unsigned char response)
{
        int retval;

        retval = usb_bulk_msg(gspca_dev->dev,
        usb_rcvbulkpipe(gspca_dev->dev, 0x84),
                                gspca_dev->usb_buf, 1, NULL, 500);
        response = gspca_dev->usb_buf[0];
        if (retval < 0)
                PDEBUG(D_ERR, "read command [%02x] error %d",
                                gspca_dev->usb_buf[0], retval);
        return retval;
}

static int jlj_start(struct gspca_dev *gspca_dev)
{
        int i;
        int retval = -1;
        u8 response = 0xff;
        struct jlj_command start_commands[] = {
                {{0x71, 0x81}, 0},
                {{0x70, 0x05}, 0},
                {{0x95, 0x70}, 1},
                {{0x71, 0x81}, 0},
                {{0x70, 0x04}, 0},
                {{0x95, 0x70}, 1},
                {{0x71, 0x00}, 0},
                {{0x70, 0x08}, 0},
                {{0x95, 0x70}, 1},
                {{0x94, 0x02}, 0},
                {{0xde, 0x24}, 0},
                {{0x94, 0x02}, 0},
                {{0xdd, 0xf0}, 0},
                {{0x94, 0x02}, 0},
                {{0xe3, 0x2c}, 0},
                {{0x94, 0x02}, 0},
                {{0xe4, 0x00}, 0},
                {{0x94, 0x02}, 0},
                {{0xe5, 0x00}, 0},
                {{0x94, 0x02}, 0},
                {{0xe6, 0x2c}, 0},
                {{0x94, 0x03}, 0},
                {{0xaa, 0x00}, 0},
                {{0x71, 0x1e}, 0},
                {{0x70, 0x06}, 0},
                {{0x71, 0x80}, 0},
                {{0x70, 0x07}, 0}
        };
        for (i = 0; i < ARRAY_SIZE(start_commands); i++) {
                retval = jlj_write2(gspca_dev, start_commands[i].instruction);
                if (retval < 0)
                        return retval;
                if (start_commands[i].ack_wanted)
                        retval = jlj_read1(gspca_dev, response);
                if (retval < 0)
                        return retval;
        }
        PDEBUG(D_ERR, "jlj_start retval is %d", retval);
        return retval;
}

static int jlj_stop(struct gspca_dev *gspca_dev)
{
        int i;
        int retval;
        struct jlj_command stop_commands[] = {
                {{0x71, 0x00}, 0},
                {{0x70, 0x09}, 0},
                {{0x71, 0x80}, 0},
                {{0x70, 0x05}, 0}
        };
        for (i = 0; i < ARRAY_SIZE(stop_commands); i++) {
                retval = jlj_write2(gspca_dev, stop_commands[i].instruction);
                if (retval < 0)
                        return retval;
        }
        return retval;
}

/* This function is called as a workqueue function and runs whenever the camera
 * is streaming data. Because it is a workqueue function it is allowed to sleep
 * so we can use synchronous USB calls. To avoid possible collisions with other
 * threads attempting to use the camera's USB interface the gspca usb_lock is
 * used when performing the one USB control operation inside the workqueue,
 * which tells the camera to close the stream. In practice the only thing
 * which needs to be protected against is the usb_set_interface call that
 * gspca makes during stream_off. Otherwise the camera doesn't provide any
 * controls that the user could try to change.
 */

static void jlj_dostream(struct work_struct *work)
{
        struct sd *dev = container_of(work, struct sd, work_struct);
        struct gspca_dev *gspca_dev = &dev->gspca_dev;
        struct gspca_frame *frame;
        int blocks_left; /* 0x200-sized blocks remaining in current frame. */
        int size_in_blocks;
        int act_len;
        int discarding = 0; /* true if we failed to get space for frame. */
        int packet_type;
        int ret;
        u8 *buffer;

        buffer = kmalloc(JEILINJ_MAX_TRANSFER, GFP_KERNEL | GFP_DMA);
        if (!buffer) {
                PDEBUG(D_ERR, "Couldn't allocate USB buffer");
                goto quit_stream;
        }
        while (gspca_dev->present && gspca_dev->streaming) {
                if (!gspca_dev->present)
                        goto quit_stream;
                /* Start a new frame, and add the JPEG header, first thing */
                frame = gspca_get_i_frame(gspca_dev);
                if (frame && !discarding)
                        gspca_frame_add(gspca_dev, FIRST_PACKET, frame,
                                        dev->jpeg_hdr, JPEG_HDR_SZ);
                 else
                        discarding = 1;
                /*
                 * Now request data block 0. Line 0 reports the size
                 * to download, in blocks of size 0x200, and also tells the
                 * "actual" data size, in bytes, which seems best to ignore.
                 */
                ret = usb_bulk_msg(gspca_dev->dev,
                                usb_rcvbulkpipe(gspca_dev->dev, 0x82),
                                buffer, JEILINJ_MAX_TRANSFER, &act_len,
                                JEILINJ_DATA_TIMEOUT);
                PDEBUG(D_STREAM,
                        "Got %d bytes out of %d for Block 0",
                        act_len, JEILINJ_MAX_TRANSFER);
                if (ret < 0 || act_len < FRAME_HEADER_LEN)
                        goto quit_stream;
                size_in_blocks = buffer[0x0a];
                blocks_left = buffer[0x0a] - 1;
                PDEBUG(D_STREAM, "blocks_left = 0x%x", blocks_left);
                packet_type = INTER_PACKET;
                if (frame && !discarding)
                        /* Toss line 0 of data block 0, keep the rest. */
                        gspca_frame_add(gspca_dev, packet_type,
                                frame, buffer + FRAME_HEADER_LEN,
                                JEILINJ_MAX_TRANSFER - FRAME_HEADER_LEN);
                        else
                                discarding = 1;
                while (blocks_left > 0) {
                        if (!gspca_dev->present)
                                goto quit_stream;
                        ret = usb_bulk_msg(gspca_dev->dev,
                                usb_rcvbulkpipe(gspca_dev->dev, 0x82),
                                buffer, JEILINJ_MAX_TRANSFER, &act_len,
                                JEILINJ_DATA_TIMEOUT);
                        if (ret < 0 || act_len < JEILINJ_MAX_TRANSFER)
                                goto quit_stream;
                        PDEBUG(D_STREAM,
                                "%d blocks remaining for frame", blocks_left);
                        blocks_left -= 1;
                        if (blocks_left == 0)
                                packet_type = LAST_PACKET;
                        else
                                packet_type = INTER_PACKET;
                        if (frame && !discarding)
                                gspca_frame_add(gspca_dev, packet_type,
                                                frame, buffer,
                                                JEILINJ_MAX_TRANSFER);
                        else
                                discarding = 1;
                }
        }
quit_stream:
        mutex_lock(&gspca_dev->usb_lock);
        if (gspca_dev->present)
                jlj_stop(gspca_dev);
        mutex_unlock(&gspca_dev->usb_lock);
        kfree(buffer);
}

/* This function is called at probe time just before sd_init */
static int sd_config(struct gspca_dev *gspca_dev,
                const struct usb_device_id *id)
{
        struct cam *cam = &gspca_dev->cam;
        struct sd *dev  = (struct sd *) gspca_dev;

        dev->quality  = 85;
        dev->jpegqual = 85;
        PDEBUG(D_PROBE,
                "JEILINJ camera detected"
                " (vid/pid 0x%04X:0x%04X)", id->idVendor, id->idProduct);
        cam->cam_mode = jlj_mode;
        cam->nmodes = 1;
        cam->bulk = 1;
        /* We don't use the buffer gspca allocates so make it small. */
        cam->bulk_size = 32;
        INIT_WORK(&dev->work_struct, jlj_dostream);
        return 0;
}

/* called on streamoff with alt==0 and on disconnect */
/* the usb_lock is held at entry - restore on exit */
static void sd_stop0(struct gspca_dev *gspca_dev)
{
        struct sd *dev = (struct sd *) gspca_dev;

        /* wait for the work queue to terminate */
        mutex_unlock(&gspca_dev->usb_lock);
        /* This waits for jlj_dostream to finish */
        destroy_workqueue(dev->work_thread);
        dev->work_thread = NULL;
        mutex_lock(&gspca_dev->usb_lock);
        kfree(dev->jpeg_hdr);
}

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

/* Set up for getting frames. */
static int sd_start(struct gspca_dev *gspca_dev)
{
        struct sd *dev = (struct sd *) gspca_dev;
        int ret;

        /* create the JPEG header */
        dev->jpeg_hdr = kmalloc(JPEG_HDR_SZ, GFP_KERNEL);
        if (dev->jpeg_hdr == NULL)
                return -ENOMEM;
        jpeg_define(dev->jpeg_hdr, gspca_dev->height, gspca_dev->width,
                        0x21);          /* JPEG 422 */
        jpeg_set_qual(dev->jpeg_hdr, dev->quality);
        PDEBUG(D_STREAM, "Start streaming at 320x240");
        ret = jlj_start(gspca_dev);
        if (ret < 0) {
                PDEBUG(D_ERR, "Start streaming command failed");
                return ret;
        }
        /* Start the workqueue function to do the streaming */
        dev->work_thread = create_singlethread_workqueue(MODULE_NAME);
        queue_work(dev->work_thread, &dev->work_struct);

        return 0;
}

/* Table of supported USB devices */
static const __devinitdata struct usb_device_id device_table[] = {
        {USB_DEVICE(0x0979, 0x0280)},
        {}
};

MODULE_DEVICE_TABLE(usb, device_table);

/* sub-driver description */
static const struct sd_desc sd_desc = {
        .name   = MODULE_NAME,
        .config = sd_config,
        .init   = sd_init,
        .start  = sd_start,
        .stop0  = sd_stop0,
};

/* -- 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,
#endif
};

/* -- module insert / remove -- */
static int __init sd_mod_init(void)
{
        int ret;

        ret = usb_register(&sd_driver);
        if (ret < 0)
                return ret;
        PDEBUG(D_PROBE, "registered");
        return 0;
}

static void __exit sd_mod_exit(void)
{
        usb_deregister(&sd_driver);
        PDEBUG(D_PROBE, "deregistered");
}

module_init(sd_mod_init);
module_exit(sd_mod_exit);