/*
 * Jeilin JL2005B/C/D library
 *
 * Copyright (C) 2011 Theodore Kilgore <kilgota@auburn.edu>
 *
 * 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.
 */

#define MODULE_NAME "jl2005bcd"

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


MODULE_AUTHOR("Theodore Kilgore <kilgota@auburn.edu>");
MODULE_DESCRIPTION("JL2005B/C/D USB Camera Driver");
MODULE_LICENSE("GPL");

/* Default timeouts, in ms */
#define JL2005C_CMD_TIMEOUT 500
#define JL2005C_DATA_TIMEOUT 1000

/* Maximum transfer size to use. */
#define JL2005C_MAX_TRANSFER 0x200
#define FRAME_HEADER_LEN 16


/* specific webcam descriptor */
struct sd {
        struct gspca_dev gspca_dev;  /* !! must be the first item */
        unsigned char firmware_id[6];
        const struct v4l2_pix_format *cap_mode;
        /* Driver stuff */
        struct work_struct work_struct;
        u8 frame_brightness;
        int block_size; /* block size of camera */
        int vga;        /* 1 if vga cam, 0 if cif cam */
};


/* Camera has two resolution settings. What they are depends on model. */
static const struct v4l2_pix_format cif_mode[] = {
        {176, 144, V4L2_PIX_FMT_JL2005BCD, V4L2_FIELD_NONE,
                .bytesperline = 176,
                .sizeimage = 176 * 144,
                .colorspace = V4L2_COLORSPACE_SRGB,
                .priv = 0},
        {352, 288, V4L2_PIX_FMT_JL2005BCD, V4L2_FIELD_NONE,
                .bytesperline = 352,
                .sizeimage = 352 * 288,
                .colorspace = V4L2_COLORSPACE_SRGB,
                .priv = 0},
};

static const struct v4l2_pix_format vga_mode[] = {
        {320, 240, V4L2_PIX_FMT_JL2005BCD, V4L2_FIELD_NONE,
                .bytesperline = 320,
                .sizeimage = 320 * 240,
                .colorspace = V4L2_COLORSPACE_SRGB,
                .priv = 0},
        {640, 480, V4L2_PIX_FMT_JL2005BCD, V4L2_FIELD_NONE,
                .bytesperline = 640,
                .sizeimage = 640 * 480,
                .colorspace = V4L2_COLORSPACE_SRGB,
                .priv = 0},
};

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

/* All commands are two bytes only */
static int jl2005c_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)
                pr_err("command write [%02x] error %d\n",
                       gspca_dev->usb_buf[0], retval);
        return retval;
}

/* Response to a command is one byte in usb_buf[0], only if requested. */
static int jl2005c_read1(struct gspca_dev *gspca_dev)
{
        int retval;

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

/* Response appears in gspca_dev->usb_buf[0] */
static int jl2005c_read_reg(struct gspca_dev *gspca_dev, unsigned char reg)
{
        int retval;

        static u8 instruction[2] = {0x95, 0x00};
        /* put register to read in byte 1 */
        instruction[1] = reg;
        /* Send the read request */
        retval = jl2005c_write2(gspca_dev, instruction);
        if (retval < 0)
                return retval;
        retval = jl2005c_read1(gspca_dev);

        return retval;
}

static int jl2005c_start_new_frame(struct gspca_dev *gspca_dev)
{
        int i;
        int retval;
        int frame_brightness = 0;

        static u8 instruction[2] = {0x7f, 0x01};

        retval = jl2005c_write2(gspca_dev, instruction);
        if (retval < 0)
                return retval;

        i = 0;
        while (i < 20 && !frame_brightness) {
                /* If we tried 20 times, give up. */
                retval = jl2005c_read_reg(gspca_dev, 0x7e);
                if (retval < 0)
                        return retval;
                frame_brightness = gspca_dev->usb_buf[0];
                retval = jl2005c_read_reg(gspca_dev, 0x7d);
                if (retval < 0)
                        return retval;
                i++;
        }
        gspca_dbg(gspca_dev, D_FRAM, "frame_brightness is 0x%02x\n",
                  gspca_dev->usb_buf[0]);
        return retval;
}

static int jl2005c_write_reg(struct gspca_dev *gspca_dev, unsigned char reg,
                                                    unsigned char value)
{
        int retval;
        u8 instruction[2];

        instruction[0] = reg;
        instruction[1] = value;

        retval = jl2005c_write2(gspca_dev, instruction);
        if (retval < 0)
                        return retval;

        return retval;
}

static int jl2005c_get_firmware_id(struct gspca_dev *gspca_dev)
{
        struct sd *sd = (struct sd *)gspca_dev;
        int i = 0;
        int retval = -1;
        unsigned char regs_to_read[] = {0x57, 0x02, 0x03, 0x5d, 0x5e, 0x5f};

        gspca_dbg(gspca_dev, D_PROBE, "Running jl2005c_get_firmware_id\n");
        /* Read the first ID byte once for warmup */
        retval = jl2005c_read_reg(gspca_dev, regs_to_read[0]);
        gspca_dbg(gspca_dev, D_PROBE, "response is %02x\n",
                  gspca_dev->usb_buf[0]);
        if (retval < 0)
                return retval;
        /* Now actually get the ID string */
        for (i = 0; i < 6; i++) {
                retval = jl2005c_read_reg(gspca_dev, regs_to_read[i]);
                if (retval < 0)
                        return retval;
                sd->firmware_id[i] = gspca_dev->usb_buf[0];
        }
        gspca_dbg(gspca_dev, D_PROBE, "firmware ID is %02x%02x%02x%02x%02x%02x\n",
                  sd->firmware_id[0],
                  sd->firmware_id[1],
                  sd->firmware_id[2],
                  sd->firmware_id[3],
                  sd->firmware_id[4],
                  sd->firmware_id[5]);
        return 0;
}

static int jl2005c_stream_start_vga_lg
                    (struct gspca_dev *gspca_dev)
{
        int i;
        int retval = -1;
        static u8 instruction[][2] = {
                {0x05, 0x00},
                {0x7c, 0x00},
                {0x7d, 0x18},
                {0x02, 0x00},
                {0x01, 0x00},
                {0x04, 0x52},
        };

        for (i = 0; i < ARRAY_SIZE(instruction); i++) {
                msleep(60);
                retval = jl2005c_write2(gspca_dev, instruction[i]);
                if (retval < 0)
                        return retval;
        }
        msleep(60);
        return retval;
}

static int jl2005c_stream_start_vga_small(struct gspca_dev *gspca_dev)
{
        int i;
        int retval = -1;
        static u8 instruction[][2] = {
                {0x06, 0x00},
                {0x7c, 0x00},
                {0x7d, 0x1a},
                {0x02, 0x00},
                {0x01, 0x00},
                {0x04, 0x52},
        };

        for (i = 0; i < ARRAY_SIZE(instruction); i++) {
                msleep(60);
                retval = jl2005c_write2(gspca_dev, instruction[i]);
                if (retval < 0)
                        return retval;
        }
        msleep(60);
        return retval;
}

static int jl2005c_stream_start_cif_lg(struct gspca_dev *gspca_dev)
{
        int i;
        int retval = -1;
        static u8 instruction[][2] = {
                {0x05, 0x00},
                {0x7c, 0x00},
                {0x7d, 0x30},
                {0x02, 0x00},
                {0x01, 0x00},
                {0x04, 0x42},
        };

        for (i = 0; i < ARRAY_SIZE(instruction); i++) {
                msleep(60);
                retval = jl2005c_write2(gspca_dev, instruction[i]);
                if (retval < 0)
                        return retval;
        }
        msleep(60);
        return retval;
}

static int jl2005c_stream_start_cif_small(struct gspca_dev *gspca_dev)
{
        int i;
        int retval = -1;
        static u8 instruction[][2] = {
                {0x06, 0x00},
                {0x7c, 0x00},
                {0x7d, 0x32},
                {0x02, 0x00},
                {0x01, 0x00},
                {0x04, 0x42},
        };

        for (i = 0; i < ARRAY_SIZE(instruction); i++) {
                msleep(60);
                retval = jl2005c_write2(gspca_dev, instruction[i]);
                if (retval < 0)
                        return retval;
        }
        msleep(60);
        return retval;
}


static int jl2005c_stop(struct gspca_dev *gspca_dev)
{
        return jl2005c_write_reg(gspca_dev, 0x07, 0x00);
}

/*
 * 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 gspca_dev->usb_buf we take the usb_lock when
 * performing USB operations using it. In practice we don't really need this
 * as the camera doesn't provide any controls.
 */
static void jl2005c_dostream(struct work_struct *work)
{
        struct sd *dev = container_of(work, struct sd, work_struct);
        struct gspca_dev *gspca_dev = &dev->gspca_dev;
        int bytes_left = 0; /* bytes remaining in current frame. */
        int data_len;   /* size to use for the next read. */
        int header_read = 0;
        unsigned char header_sig[2] = {0x4a, 0x4c};
        int act_len;
        int packet_type;
        int ret;
        u8 *buffer;

        buffer = kmalloc(JL2005C_MAX_TRANSFER, GFP_KERNEL | GFP_DMA);
        if (!buffer) {
                pr_err("Couldn't allocate USB buffer\n");
                goto quit_stream;
        }

        while (gspca_dev->present && gspca_dev->streaming) {
#ifdef CONFIG_PM
                if (gspca_dev->frozen)
                        break;
#endif
                /* Check if this is a new frame. If so, start the frame first */
                if (!header_read) {
                        mutex_lock(&gspca_dev->usb_lock);
                        ret = jl2005c_start_new_frame(gspca_dev);
                        mutex_unlock(&gspca_dev->usb_lock);
                        if (ret < 0)
                                goto quit_stream;
                        ret = usb_bulk_msg(gspca_dev->dev,
                                usb_rcvbulkpipe(gspca_dev->dev, 0x82),
                                buffer, JL2005C_MAX_TRANSFER, &act_len,
                                JL2005C_DATA_TIMEOUT);
                        gspca_dbg(gspca_dev, D_PACK,
                                  "Got %d bytes out of %d for header\n",
                                  act_len, JL2005C_MAX_TRANSFER);
                        if (ret < 0 || act_len < JL2005C_MAX_TRANSFER)
                                goto quit_stream;
                        /* Check whether we actually got the first blodk */
                        if (memcmp(header_sig, buffer, 2) != 0) {
                                pr_err("First block is not the first block\n");
                                goto quit_stream;
                        }
                        /* total size to fetch is byte 7, times blocksize
                         * of which we already got act_len */
                        bytes_left = buffer[0x07] * dev->block_size - act_len;
                        gspca_dbg(gspca_dev, D_PACK, "bytes_left = 0x%x\n",
                                  bytes_left);
                        /* We keep the header. It has other information, too.*/
                        packet_type = FIRST_PACKET;
                        gspca_frame_add(gspca_dev, packet_type,
                                        buffer, act_len);
                        header_read = 1;
                }
                while (bytes_left > 0 && gspca_dev->present) {
                        data_len = bytes_left > JL2005C_MAX_TRANSFER ?
                                JL2005C_MAX_TRANSFER : bytes_left;
                        ret = usb_bulk_msg(gspca_dev->dev,
                                usb_rcvbulkpipe(gspca_dev->dev, 0x82),
                                buffer, data_len, &act_len,
                                JL2005C_DATA_TIMEOUT);
                        if (ret < 0 || act_len < data_len)
                                goto quit_stream;
                        gspca_dbg(gspca_dev, D_PACK,
                                  "Got %d bytes out of %d for frame\n",
                                  data_len, bytes_left);
                        bytes_left -= data_len;
                        if (bytes_left == 0) {
                                packet_type = LAST_PACKET;
                                header_read = 0;
                        } else
                                packet_type = INTER_PACKET;
                        gspca_frame_add(gspca_dev, packet_type,
                                        buffer, data_len);
                }
        }
quit_stream:
        if (gspca_dev->present) {
                mutex_lock(&gspca_dev->usb_lock);
                jl2005c_stop(gspca_dev);
                mutex_unlock(&gspca_dev->usb_lock);
        }
        kfree(buffer);
}




/* This function is called at probe time */
static int sd_config(struct gspca_dev *gspca_dev,
                        const struct usb_device_id *id)
{
        struct cam *cam;
        struct sd *sd = (struct sd *) gspca_dev;

        cam = &gspca_dev->cam;
        /* We don't use the buffer gspca allocates so make it small. */
        cam->bulk_size = 64;
        cam->bulk = 1;
        /* For the rest, the camera needs to be detected */
        jl2005c_get_firmware_id(gspca_dev);
        /* Here are some known firmware IDs
         * First some JL2005B cameras
         * {0x41, 0x07, 0x04, 0x2c, 0xe8, 0xf2} Sakar KidzCam
         * {0x45, 0x02, 0x08, 0xb9, 0x00, 0xd2} No-name JL2005B
         * JL2005C cameras
         * {0x01, 0x0c, 0x16, 0x10, 0xf8, 0xc8} Argus DC-1512
         * {0x12, 0x04, 0x03, 0xc0, 0x00, 0xd8} ICarly
         * {0x86, 0x08, 0x05, 0x02, 0x00, 0xd4} Jazz
         *
         * Based upon this scanty evidence, we can detect a CIF camera by
         * testing byte 0 for 0x4x.
         */
        if ((sd->firmware_id[0] & 0xf0) == 0x40) {
                cam->cam_mode   = cif_mode;
                cam->nmodes     = ARRAY_SIZE(cif_mode);
                sd->block_size  = 0x80;
        } else {
                cam->cam_mode   = vga_mode;
                cam->nmodes     = ARRAY_SIZE(vga_mode);
                sd->block_size  = 0x200;
        }

        INIT_WORK(&sd->work_struct, jl2005c_dostream);

        return 0;
}

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

static int sd_start(struct gspca_dev *gspca_dev)
{

        struct sd *sd = (struct sd *) gspca_dev;
        sd->cap_mode = gspca_dev->cam.cam_mode;

        switch (gspca_dev->pixfmt.width) {
        case 640:
                gspca_dbg(gspca_dev, D_STREAM, "Start streaming at vga resolution\n");
                jl2005c_stream_start_vga_lg(gspca_dev);
                break;
        case 320:
                gspca_dbg(gspca_dev, D_STREAM, "Start streaming at qvga resolution\n");
                jl2005c_stream_start_vga_small(gspca_dev);
                break;
        case 352:
                gspca_dbg(gspca_dev, D_STREAM, "Start streaming at cif resolution\n");
                jl2005c_stream_start_cif_lg(gspca_dev);
                break;
        case 176:
                gspca_dbg(gspca_dev, D_STREAM, "Start streaming at qcif resolution\n");
                jl2005c_stream_start_cif_small(gspca_dev);
                break;
        default:
                pr_err("Unknown resolution specified\n");
                return -1;
        }

        schedule_work(&sd->work_struct);

        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 sq905c_dostream to finish */
        flush_work(&dev->work_struct);
        mutex_lock(&gspca_dev->usb_lock);
}



/* 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,
};

/* -- module initialisation -- */
static const struct usb_device_id device_table[] = {
        {USB_DEVICE(0x0979, 0x0227)},
        {}
};
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);