/*
 * Copyright (c) 2001 Jean-Fredric Clere, Nikolas Zimmermann, Georg Acher
 *                    Mark Cave-Ayland, Carlo E Prelz, Dick Streefland
 * Copyright (c) 2002, 2003 Tuukka Toivonen
 * Copyright (c) 2008 Erik Andrén
 *
 * 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.
 *
 * P/N 861037:      Sensor HDCS1000        ASIC STV0600
 * P/N 861050-0010: Sensor HDCS1000        ASIC STV0600
 * P/N 861050-0020: Sensor Photobit PB100  ASIC STV0600-1 - QuickCam Express
 * P/N 861055:      Sensor ST VV6410       ASIC STV0610   - LEGO cam
 * P/N 861075-0040: Sensor HDCS1000        ASIC
 * P/N 961179-0700: Sensor ST VV6410       ASIC STV0602   - Dexxa WebCam USB
 * P/N 861040-0000: Sensor ST VV6410       ASIC STV0610   - QuickCam Web
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/input.h>
#include "stv06xx_sensor.h"

MODULE_AUTHOR("Erik Andrén");
MODULE_DESCRIPTION("STV06XX USB Camera Driver");
MODULE_LICENSE("GPL");

static bool dump_bridge;
static bool dump_sensor;

int stv06xx_write_bridge(struct sd *sd, u16 address, u16 i2c_data)
{
        int err;
        struct gspca_dev *gspca_dev = (struct gspca_dev *)sd;
        struct usb_device *udev = sd->gspca_dev.dev;
        __u8 *buf = sd->gspca_dev.usb_buf;

        u8 len = (i2c_data > 0xff) ? 2 : 1;

        buf[0] = i2c_data & 0xff;
        buf[1] = (i2c_data >> 8) & 0xff;

        err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
                              0x04, 0x40, address, 0, buf, len,
                              STV06XX_URB_MSG_TIMEOUT);

        gspca_dbg(gspca_dev, D_CONF, "Written 0x%x to address 0x%x, status: %d\n",
                  i2c_data, address, err);

        return (err < 0) ? err : 0;
}

int stv06xx_read_bridge(struct sd *sd, u16 address, u8 *i2c_data)
{
        int err;
        struct gspca_dev *gspca_dev = (struct gspca_dev *)sd;
        struct usb_device *udev = sd->gspca_dev.dev;
        __u8 *buf = sd->gspca_dev.usb_buf;

        err = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
                              0x04, 0xc0, address, 0, buf, 1,
                              STV06XX_URB_MSG_TIMEOUT);

        *i2c_data = buf[0];

        gspca_dbg(gspca_dev, D_CONF, "Reading 0x%x from address 0x%x, status %d\n",
                  *i2c_data, address, err);

        return (err < 0) ? err : 0;
}

/* Wraps the normal write sensor bytes / words functions for writing a
   single value */
int stv06xx_write_sensor(struct sd *sd, u8 address, u16 value)
{
        if (sd->sensor->i2c_len == 2) {
                u16 data[2] = { address, value };
                return stv06xx_write_sensor_words(sd, data, 1);
        } else {
                u8 data[2] = { address, value };
                return stv06xx_write_sensor_bytes(sd, data, 1);
        }
}

static int stv06xx_write_sensor_finish(struct sd *sd)
{
        int err = 0;

        if (sd->bridge == BRIDGE_STV610) {
                struct usb_device *udev = sd->gspca_dev.dev;
                __u8 *buf = sd->gspca_dev.usb_buf;

                buf[0] = 0;
                err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
                                      0x04, 0x40, 0x1704, 0, buf, 1,
                                      STV06XX_URB_MSG_TIMEOUT);
        }

        return (err < 0) ? err : 0;
}

int stv06xx_write_sensor_bytes(struct sd *sd, const u8 *data, u8 len)
{
        int err, i, j;
        struct gspca_dev *gspca_dev = (struct gspca_dev *)sd;
        struct usb_device *udev = sd->gspca_dev.dev;
        __u8 *buf = sd->gspca_dev.usb_buf;

        gspca_dbg(gspca_dev, D_CONF, "I2C: Command buffer contains %d entries\n",
                  len);
        for (i = 0; i < len;) {
                /* Build the command buffer */
                memset(buf, 0, I2C_BUFFER_LENGTH);
                for (j = 0; j < I2C_MAX_BYTES && i < len; j++, i++) {
                        buf[j] = data[2*i];
                        buf[0x10 + j] = data[2*i+1];
                        gspca_dbg(gspca_dev, D_CONF, "I2C: Writing 0x%02x to reg 0x%02x\n",
                                  data[2*i+1], data[2*i]);
                }
                buf[0x20] = sd->sensor->i2c_addr;
                buf[0x21] = j - 1; /* Number of commands to send - 1 */
                buf[0x22] = I2C_WRITE_CMD;
                err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
                                      0x04, 0x40, 0x0400, 0, buf,
                                      I2C_BUFFER_LENGTH,
                                      STV06XX_URB_MSG_TIMEOUT);
                if (err < 0)
                        return err;
        }
        return stv06xx_write_sensor_finish(sd);
}

int stv06xx_write_sensor_words(struct sd *sd, const u16 *data, u8 len)
{
        int err, i, j;
        struct gspca_dev *gspca_dev = (struct gspca_dev *)sd;
        struct usb_device *udev = sd->gspca_dev.dev;
        __u8 *buf = sd->gspca_dev.usb_buf;

        gspca_dbg(gspca_dev, D_CONF, "I2C: Command buffer contains %d entries\n",
                  len);

        for (i = 0; i < len;) {
                /* Build the command buffer */
                memset(buf, 0, I2C_BUFFER_LENGTH);
                for (j = 0; j < I2C_MAX_WORDS && i < len; j++, i++) {
                        buf[j] = data[2*i];
                        buf[0x10 + j * 2] = data[2*i+1];
                        buf[0x10 + j * 2 + 1] = data[2*i+1] >> 8;
                        gspca_dbg(gspca_dev, D_CONF, "I2C: Writing 0x%04x to reg 0x%02x\n",
                                  data[2*i+1], data[2*i]);
                }
                buf[0x20] = sd->sensor->i2c_addr;
                buf[0x21] = j - 1; /* Number of commands to send - 1 */
                buf[0x22] = I2C_WRITE_CMD;
                err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
                                0x04, 0x40, 0x0400, 0, buf,
                                I2C_BUFFER_LENGTH,
                                STV06XX_URB_MSG_TIMEOUT);
                if (err < 0)
                        return err;
        }
        return stv06xx_write_sensor_finish(sd);
}

int stv06xx_read_sensor(struct sd *sd, const u8 address, u16 *value)
{
        int err;
        struct gspca_dev *gspca_dev = (struct gspca_dev *)sd;
        struct usb_device *udev = sd->gspca_dev.dev;
        __u8 *buf = sd->gspca_dev.usb_buf;

        err = stv06xx_write_bridge(sd, STV_I2C_FLUSH, sd->sensor->i2c_flush);
        if (err < 0)
                return err;

        /* Clear mem */
        memset(buf, 0, I2C_BUFFER_LENGTH);

        buf[0] = address;
        buf[0x20] = sd->sensor->i2c_addr;
        buf[0x21] = 0;

        /* Read I2C register */
        buf[0x22] = I2C_READ_CMD;

        err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
                              0x04, 0x40, 0x1400, 0, buf, I2C_BUFFER_LENGTH,
                              STV06XX_URB_MSG_TIMEOUT);
        if (err < 0) {
                pr_err("I2C: Read error writing address: %d\n", err);
                return err;
        }

        err = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
                              0x04, 0xc0, 0x1410, 0, buf, sd->sensor->i2c_len,
                              STV06XX_URB_MSG_TIMEOUT);
        if (sd->sensor->i2c_len == 2)
                *value = buf[0] | (buf[1] << 8);
        else
                *value = buf[0];

        gspca_dbg(gspca_dev, D_CONF, "I2C: Read 0x%x from address 0x%x, status: %d\n",
                  *value, address, err);

        return (err < 0) ? err : 0;
}

/* Dumps all bridge registers */
static void stv06xx_dump_bridge(struct sd *sd)
{
        int i;
        u8 data, buf;

        pr_info("Dumping all stv06xx bridge registers\n");
        for (i = 0x1400; i < 0x160f; i++) {
                stv06xx_read_bridge(sd, i, &data);

                pr_info("Read 0x%x from address 0x%x\n", data, i);
        }

        pr_info("Testing stv06xx bridge registers for writability\n");
        for (i = 0x1400; i < 0x160f; i++) {
                stv06xx_read_bridge(sd, i, &data);
                buf = data;

                stv06xx_write_bridge(sd, i, 0xff);
                stv06xx_read_bridge(sd, i, &data);
                if (data == 0xff)
                        pr_info("Register 0x%x is read/write\n", i);
                else if (data != buf)
                        pr_info("Register 0x%x is read/write, but only partially\n",
                                i);
                else
                        pr_info("Register 0x%x is read-only\n", i);

                stv06xx_write_bridge(sd, i, buf);
        }
}

/* this function is called at probe and resume time */
static int stv06xx_init(struct gspca_dev *gspca_dev)
{
        struct sd *sd = (struct sd *) gspca_dev;
        int err;

        gspca_dbg(gspca_dev, D_PROBE, "Initializing camera\n");

        /* Let the usb init settle for a bit
           before performing the initialization */
        msleep(250);

        err = sd->sensor->init(sd);

        if (dump_sensor && sd->sensor->dump)
                sd->sensor->dump(sd);

        return (err < 0) ? err : 0;
}

/* this function is called at probe time */
static int stv06xx_init_controls(struct gspca_dev *gspca_dev)
{
        struct sd *sd = (struct sd *) gspca_dev;

        gspca_dbg(gspca_dev, D_PROBE, "Initializing controls\n");

        gspca_dev->vdev.ctrl_handler = &gspca_dev->ctrl_handler;
        return sd->sensor->init_controls(sd);
}

/* Start the camera */
static int stv06xx_start(struct gspca_dev *gspca_dev)
{
        struct sd *sd = (struct sd *) gspca_dev;
        struct usb_host_interface *alt;
        struct usb_interface *intf;
        int err, packet_size;

        intf = usb_ifnum_to_if(sd->gspca_dev.dev, sd->gspca_dev.iface);
        alt = usb_altnum_to_altsetting(intf, sd->gspca_dev.alt);
        if (!alt) {
                gspca_err(gspca_dev, "Couldn't get altsetting\n");
                return -EIO;
        }

        packet_size = le16_to_cpu(alt->endpoint[0].desc.wMaxPacketSize);
        err = stv06xx_write_bridge(sd, STV_ISO_SIZE_L, packet_size);
        if (err < 0)
                return err;

        /* Prepare the sensor for start */
        err = sd->sensor->start(sd);
        if (err < 0)
                goto out;

        /* Start isochronous streaming */
        err = stv06xx_write_bridge(sd, STV_ISO_ENABLE, 1);

out:
        if (err < 0)
                gspca_dbg(gspca_dev, D_STREAM, "Starting stream failed\n");
        else
                gspca_dbg(gspca_dev, D_STREAM, "Started streaming\n");

        return (err < 0) ? err : 0;
}

static int stv06xx_isoc_init(struct gspca_dev *gspca_dev)
{
        struct usb_host_interface *alt;
        struct sd *sd = (struct sd *) gspca_dev;

        /* Start isoc bandwidth "negotiation" at max isoc bandwidth */
        alt = &gspca_dev->dev->actconfig->intf_cache[0]->altsetting[1];
        alt->endpoint[0].desc.wMaxPacketSize =
                cpu_to_le16(sd->sensor->max_packet_size[gspca_dev->curr_mode]);

        return 0;
}

static int stv06xx_isoc_nego(struct gspca_dev *gspca_dev)
{
        int ret, packet_size, min_packet_size;
        struct usb_host_interface *alt;
        struct sd *sd = (struct sd *) gspca_dev;

        alt = &gspca_dev->dev->actconfig->intf_cache[0]->altsetting[1];
        packet_size = le16_to_cpu(alt->endpoint[0].desc.wMaxPacketSize);
        min_packet_size = sd->sensor->min_packet_size[gspca_dev->curr_mode];
        if (packet_size <= min_packet_size)
                return -EIO;

        packet_size -= 100;
        if (packet_size < min_packet_size)
                packet_size = min_packet_size;
        alt->endpoint[0].desc.wMaxPacketSize = cpu_to_le16(packet_size);

        ret = usb_set_interface(gspca_dev->dev, gspca_dev->iface, 1);
        if (ret < 0)
                gspca_err(gspca_dev, "set alt 1 err %d\n", ret);

        return ret;
}

static void stv06xx_stopN(struct gspca_dev *gspca_dev)
{
        int err;
        struct sd *sd = (struct sd *) gspca_dev;

        /* stop ISO-streaming */
        err = stv06xx_write_bridge(sd, STV_ISO_ENABLE, 0);
        if (err < 0)
                goto out;

        err = sd->sensor->stop(sd);

out:
        if (err < 0)
                gspca_dbg(gspca_dev, D_STREAM, "Failed to stop stream\n");
        else
                gspca_dbg(gspca_dev, D_STREAM, "Stopped streaming\n");
}

/*
 * Analyse an USB packet of the data stream and store it appropriately.
 * Each packet contains an integral number of chunks. Each chunk has
 * 2-bytes identification, followed by 2-bytes that describe the chunk
 * length. Known/guessed chunk identifications are:
 * 8001/8005/C001/C005 - Begin new frame
 * 8002/8006/C002/C006 - End frame
 * 0200/4200           - Contains actual image data, bayer or compressed
 * 0005                - 11 bytes of unknown data
 * 0100                - 2 bytes of unknown data
 * The 0005 and 0100 chunks seem to appear only in compressed stream.
 */
static void stv06xx_pkt_scan(struct gspca_dev *gspca_dev,
                        u8 *data,                       /* isoc packet */
                        int len)                        /* iso packet length */
{
        struct sd *sd = (struct sd *) gspca_dev;

        gspca_dbg(gspca_dev, D_PACK, "Packet of length %d arrived\n", len);

        /* A packet may contain several frames
           loop until the whole packet is reached */
        while (len) {
                int id, chunk_len;

                if (len < 4) {
                        gspca_dbg(gspca_dev, D_PACK, "Packet is smaller than 4 bytes\n");
                        return;
                }

                /* Capture the id */
                id = (data[0] << 8) | data[1];

                /* Capture the chunk length */
                chunk_len = (data[2] << 8) | data[3];
                gspca_dbg(gspca_dev, D_PACK, "Chunk id: %x, length: %d\n",
                          id, chunk_len);

                data += 4;
                len -= 4;

                if (len < chunk_len) {
                        gspca_err(gspca_dev, "URB packet length is smaller than the specified chunk length\n");
                        gspca_dev->last_packet_type = DISCARD_PACKET;
                        return;
                }

                /* First byte seem to be 02=data 2nd byte is unknown??? */
                if (sd->bridge == BRIDGE_ST6422 && (id & 0xff00) == 0x0200)
                        goto frame_data;

                switch (id) {
                case 0x0200:
                case 0x4200:
frame_data:
                        gspca_dbg(gspca_dev, D_PACK, "Frame data packet detected\n");

                        if (sd->to_skip) {
                                int skip = (sd->to_skip < chunk_len) ?
                                            sd->to_skip : chunk_len;
                                data += skip;
                                len -= skip;
                                chunk_len -= skip;
                                sd->to_skip -= skip;
                        }

                        gspca_frame_add(gspca_dev, INTER_PACKET,
                                        data, chunk_len);
                        break;

                case 0x8001:
                case 0x8005:
                case 0xc001:
                case 0xc005:
                        gspca_dbg(gspca_dev, D_PACK, "Starting new frame\n");

                        /* Create a new frame, chunk length should be zero */
                        gspca_frame_add(gspca_dev, FIRST_PACKET,
                                        NULL, 0);

                        if (sd->bridge == BRIDGE_ST6422)
                                sd->to_skip = gspca_dev->pixfmt.width * 4;

                        if (chunk_len)
                                gspca_err(gspca_dev, "Chunk length is non-zero on a SOF\n");
                        break;

                case 0x8002:
                case 0x8006:
                case 0xc002:
                        gspca_dbg(gspca_dev, D_PACK, "End of frame detected\n");

                        /* Complete the last frame (if any) */
                        gspca_frame_add(gspca_dev, LAST_PACKET,
                                        NULL, 0);

                        if (chunk_len)
                                gspca_err(gspca_dev, "Chunk length is non-zero on a EOF\n");
                        break;

                case 0x0005:
                        gspca_dbg(gspca_dev, D_PACK, "Chunk 0x005 detected\n");
                        /* Unknown chunk with 11 bytes of data,
                           occurs just before end of each frame
                           in compressed mode */
                        break;

                case 0x0100:
                        gspca_dbg(gspca_dev, D_PACK, "Chunk 0x0100 detected\n");
                        /* Unknown chunk with 2 bytes of data,
                           occurs 2-3 times per USB interrupt */
                        break;
                case 0x42ff:
                        gspca_dbg(gspca_dev, D_PACK, "Chunk 0x42ff detected\n");
                        /* Special chunk seen sometimes on the ST6422 */
                        break;
                default:
                        gspca_dbg(gspca_dev, D_PACK, "Unknown chunk 0x%04x detected\n",
                                  id);
                        /* Unknown chunk */
                }
                data    += chunk_len;
                len     -= chunk_len;
        }
}

#if IS_ENABLED(CONFIG_INPUT)
static int sd_int_pkt_scan(struct gspca_dev *gspca_dev,
                        u8 *data,               /* interrupt packet data */
                        int len)                /* interrupt packet length */
{
        int ret = -EINVAL;

        if (len == 1 && (data[0] == 0x80 || data[0] == 0x10)) {
                input_report_key(gspca_dev->input_dev, KEY_CAMERA, 1);
                input_sync(gspca_dev->input_dev);
                ret = 0;
        }

        if (len == 1 && (data[0] == 0x88 || data[0] == 0x11)) {
                input_report_key(gspca_dev->input_dev, KEY_CAMERA, 0);
                input_sync(gspca_dev->input_dev);
                ret = 0;
        }

        return ret;
}
#endif

static int stv06xx_config(struct gspca_dev *gspca_dev,
                          const struct usb_device_id *id);

/* sub-driver description */
static const struct sd_desc sd_desc = {
        .name = MODULE_NAME,
        .config = stv06xx_config,
        .init = stv06xx_init,
        .init_controls = stv06xx_init_controls,
        .start = stv06xx_start,
        .stopN = stv06xx_stopN,
        .pkt_scan = stv06xx_pkt_scan,
        .isoc_init = stv06xx_isoc_init,
        .isoc_nego = stv06xx_isoc_nego,
#if IS_ENABLED(CONFIG_INPUT)
        .int_pkt_scan = sd_int_pkt_scan,
#endif
};

/* This function is called at probe time */
static int stv06xx_config(struct gspca_dev *gspca_dev,
                          const struct usb_device_id *id)
{
        struct sd *sd = (struct sd *) gspca_dev;

        gspca_dbg(gspca_dev, D_PROBE, "Configuring camera\n");

        sd->bridge = id->driver_info;
        gspca_dev->sd_desc = &sd_desc;

        if (dump_bridge)
                stv06xx_dump_bridge(sd);

        sd->sensor = &stv06xx_sensor_st6422;
        if (!sd->sensor->probe(sd))
                return 0;

        sd->sensor = &stv06xx_sensor_vv6410;
        if (!sd->sensor->probe(sd))
                return 0;

        sd->sensor = &stv06xx_sensor_hdcs1x00;
        if (!sd->sensor->probe(sd))
                return 0;

        sd->sensor = &stv06xx_sensor_hdcs1020;
        if (!sd->sensor->probe(sd))
                return 0;

        sd->sensor = &stv06xx_sensor_pb0100;
        if (!sd->sensor->probe(sd))
                return 0;

        sd->sensor = NULL;
        return -ENODEV;
}



/* -- module initialisation -- */
static const struct usb_device_id device_table[] = {
        {USB_DEVICE(0x046d, 0x0840), .driver_info = BRIDGE_STV600 },    /* QuickCam Express */
        {USB_DEVICE(0x046d, 0x0850), .driver_info = BRIDGE_STV610 },    /* LEGO cam / QuickCam Web */
        {USB_DEVICE(0x046d, 0x0870), .driver_info = BRIDGE_STV602 },    /* Dexxa WebCam USB */
        {USB_DEVICE(0x046D, 0x08F0), .driver_info = BRIDGE_ST6422 },    /* QuickCam Messenger */
        {USB_DEVICE(0x046D, 0x08F5), .driver_info = BRIDGE_ST6422 },    /* QuickCam Communicate */
        {USB_DEVICE(0x046D, 0x08F6), .driver_info = BRIDGE_ST6422 },    /* QuickCam Messenger (new) */
        {}
};
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 void sd_disconnect(struct usb_interface *intf)
{
        struct gspca_dev *gspca_dev = usb_get_intfdata(intf);
        struct sd *sd = (struct sd *) gspca_dev;
        void *priv = sd->sensor_priv;
        gspca_dbg(gspca_dev, D_PROBE, "Disconnecting the stv06xx device\n");

        sd->sensor = NULL;
        gspca_disconnect(intf);
        kfree(priv);
}

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

module_usb_driver(sd_driver);

module_param(dump_bridge, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(dump_bridge, "Dumps all usb bridge registers at startup");

module_param(dump_sensor, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(dump_sensor, "Dumps all sensor registers at startup");