/*
 * 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
 * Copyright (c) 2008 Chia-I Wu
 *
 * 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.
 *
 * 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
 *
 * 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 "stv06xx_hdcs.h"

static struct v4l2_pix_format hdcs1x00_mode[] = {
        {
                HDCS_1X00_DEF_WIDTH,
                HDCS_1X00_DEF_HEIGHT,
                V4L2_PIX_FMT_SGRBG8,
                V4L2_FIELD_NONE,
                .sizeimage =
                        HDCS_1X00_DEF_WIDTH * HDCS_1X00_DEF_HEIGHT,
                .bytesperline = HDCS_1X00_DEF_WIDTH,
                .colorspace = V4L2_COLORSPACE_SRGB,
                .priv = 1
        }
};

static struct v4l2_pix_format hdcs1020_mode[] = {
        {
                HDCS_1020_DEF_WIDTH,
                HDCS_1020_DEF_HEIGHT,
                V4L2_PIX_FMT_SGRBG8,
                V4L2_FIELD_NONE,
                .sizeimage =
                        HDCS_1020_DEF_WIDTH * HDCS_1020_DEF_HEIGHT,
                .bytesperline = HDCS_1020_DEF_WIDTH,
                .colorspace = V4L2_COLORSPACE_SRGB,
                .priv = 1
        }
};

enum hdcs_power_state {
        HDCS_STATE_SLEEP,
        HDCS_STATE_IDLE,
        HDCS_STATE_RUN
};

/* no lock? */
struct hdcs {
        enum hdcs_power_state state;
        int w, h;

        /* visible area of the sensor array */
        struct {
                int left, top;
                int width, height;
                int border;
        } array;

        struct {
                /* Column timing overhead */
                u8 cto;
                /* Column processing overhead */
                u8 cpo;
                /* Row sample period constant */
                u16 rs;
                /* Exposure reset duration */
                u16 er;
        } exp;

        int psmp;
};

static int hdcs_reg_write_seq(struct sd *sd, u8 reg, u8 *vals, u8 len)
{
        u8 regs[I2C_MAX_BYTES * 2];
        int i;

        if (unlikely((len <= 0) || (len >= I2C_MAX_BYTES) ||
                     (reg + len > 0xff)))
                return -EINVAL;

        for (i = 0; i < len; i++) {
                regs[2 * i] = reg;
                regs[2 * i + 1] = vals[i];
                /* All addresses are shifted left one bit
                 * as bit 0 toggles r/w */
                reg += 2;
        }

        return stv06xx_write_sensor_bytes(sd, regs, len);
}

static int hdcs_set_state(struct sd *sd, enum hdcs_power_state state)
{
        struct hdcs *hdcs = sd->sensor_priv;
        u8 val;
        int ret;

        if (hdcs->state == state)
                return 0;

        /* we need to go idle before running or sleeping */
        if (hdcs->state != HDCS_STATE_IDLE) {
                ret = stv06xx_write_sensor(sd, HDCS_REG_CONTROL(sd), 0);
                if (ret)
                        return ret;
        }

        hdcs->state = HDCS_STATE_IDLE;

        if (state == HDCS_STATE_IDLE)
                return 0;

        switch (state) {
        case HDCS_STATE_SLEEP:
                val = HDCS_SLEEP_MODE;
                break;

        case HDCS_STATE_RUN:
                val = HDCS_RUN_ENABLE;
                break;

        default:
                return -EINVAL;
        }

        ret = stv06xx_write_sensor(sd, HDCS_REG_CONTROL(sd), val);

        /* Update the state if the write succeeded */
        if (!ret)
                hdcs->state = state;

        return ret;
}

static int hdcs_reset(struct sd *sd)
{
        struct hdcs *hdcs = sd->sensor_priv;
        int err;

        err = stv06xx_write_sensor(sd, HDCS_REG_CONTROL(sd), 1);
        if (err < 0)
                return err;

        err = stv06xx_write_sensor(sd, HDCS_REG_CONTROL(sd), 0);
        if (err < 0)
                hdcs->state = HDCS_STATE_IDLE;

        return err;
}

static int hdcs_set_exposure(struct gspca_dev *gspca_dev, __s32 val)
{
        struct sd *sd = (struct sd *) gspca_dev;
        struct hdcs *hdcs = sd->sensor_priv;
        int rowexp, srowexp;
        int max_srowexp;
        /* Column time period */
        int ct;
        /* Column processing period */
        int cp;
        /* Row processing period */
        int rp;
        /* Minimum number of column timing periods
           within the column processing period */
        int mnct;
        int cycles, err;
        u8 exp[14];

        cycles = val * HDCS_CLK_FREQ_MHZ * 257;

        ct = hdcs->exp.cto + hdcs->psmp + (HDCS_ADC_START_SIG_DUR + 2);
        cp = hdcs->exp.cto + (hdcs->w * ct / 2);

        /* the cycles one row takes */
        rp = hdcs->exp.rs + cp;

        rowexp = cycles / rp;

        /* the remaining cycles */
        cycles -= rowexp * rp;

        /* calculate sub-row exposure */
        if (IS_1020(sd)) {
                /* see HDCS-1020 datasheet 3.5.6.4, p. 63 */
                srowexp = hdcs->w - (cycles + hdcs->exp.er + 13) / ct;

                mnct = (hdcs->exp.er + 12 + ct - 1) / ct;
                max_srowexp = hdcs->w - mnct;
        } else {
                /* see HDCS-1000 datasheet 3.4.5.5, p. 61 */
                srowexp = cp - hdcs->exp.er - 6 - cycles;

                mnct = (hdcs->exp.er + 5 + ct - 1) / ct;
                max_srowexp = cp - mnct * ct - 1;
        }

        if (srowexp < 0)
                srowexp = 0;
        else if (srowexp > max_srowexp)
                srowexp = max_srowexp;

        if (IS_1020(sd)) {
                exp[0] = HDCS20_CONTROL;
                exp[1] = 0x00;          /* Stop streaming */
                exp[2] = HDCS_ROWEXPL;
                exp[3] = rowexp & 0xff;
                exp[4] = HDCS_ROWEXPH;
                exp[5] = rowexp >> 8;
                exp[6] = HDCS20_SROWEXP;
                exp[7] = (srowexp >> 2) & 0xff;
                exp[8] = HDCS20_ERROR;
                exp[9] = 0x10;          /* Clear exposure error flag*/
                exp[10] = HDCS20_CONTROL;
                exp[11] = 0x04;         /* Restart streaming */
                err = stv06xx_write_sensor_bytes(sd, exp, 6);
        } else {
                exp[0] = HDCS00_CONTROL;
                exp[1] = 0x00;         /* Stop streaming */
                exp[2] = HDCS_ROWEXPL;
                exp[3] = rowexp & 0xff;
                exp[4] = HDCS_ROWEXPH;
                exp[5] = rowexp >> 8;
                exp[6] = HDCS00_SROWEXPL;
                exp[7] = srowexp & 0xff;
                exp[8] = HDCS00_SROWEXPH;
                exp[9] = srowexp >> 8;
                exp[10] = HDCS_STATUS;
                exp[11] = 0x10;         /* Clear exposure error flag*/
                exp[12] = HDCS00_CONTROL;
                exp[13] = 0x04;         /* Restart streaming */
                err = stv06xx_write_sensor_bytes(sd, exp, 7);
                if (err < 0)
                        return err;
        }
        PDEBUG(D_CONF, "Writing exposure %d, rowexp %d, srowexp %d",
               val, rowexp, srowexp);
        return err;
}

static int hdcs_set_gains(struct sd *sd, u8 g)
{
        int err;
        u8 gains[4];

        /* the voltage gain Av = (1 + 19 * val / 127) * (1 + bit7) */
        if (g > 127)
                g = 0x80 | (g / 2);

        gains[0] = g;
        gains[1] = g;
        gains[2] = g;
        gains[3] = g;

        err = hdcs_reg_write_seq(sd, HDCS_ERECPGA, gains, 4);
        return err;
}

static int hdcs_set_gain(struct gspca_dev *gspca_dev, __s32 val)
{
        PDEBUG(D_CONF, "Writing gain %d", val);
        return hdcs_set_gains((struct sd *) gspca_dev,
                               val & 0xff);
}

static int hdcs_set_size(struct sd *sd,
                unsigned int width, unsigned int height)
{
        struct hdcs *hdcs = sd->sensor_priv;
        u8 win[4];
        unsigned int x, y;
        int err;

        /* must be multiple of 4 */
        width = (width + 3) & ~0x3;
        height = (height + 3) & ~0x3;

        if (width > hdcs->array.width)
                width = hdcs->array.width;

        if (IS_1020(sd)) {
                /* the borders are also invalid */
                if (height + 2 * hdcs->array.border + HDCS_1020_BOTTOM_Y_SKIP
                                  > hdcs->array.height)
                        height = hdcs->array.height - 2 * hdcs->array.border -
                                HDCS_1020_BOTTOM_Y_SKIP;

                y = (hdcs->array.height - HDCS_1020_BOTTOM_Y_SKIP - height) / 2
                                + hdcs->array.top;
        } else {
                if (height > hdcs->array.height)
                        height = hdcs->array.height;

                y = hdcs->array.top + (hdcs->array.height - height) / 2;
        }

        x = hdcs->array.left + (hdcs->array.width - width) / 2;

        win[0] = y / 4;
        win[1] = x / 4;
        win[2] = (y + height) / 4 - 1;
        win[3] = (x + width) / 4 - 1;

        err = hdcs_reg_write_seq(sd, HDCS_FWROW, win, 4);
        if (err < 0)
                return err;

        /* Update the current width and height */
        hdcs->w = width;
        hdcs->h = height;
        return err;
}

static int hdcs_s_ctrl(struct v4l2_ctrl *ctrl)
{
        struct gspca_dev *gspca_dev =
                container_of(ctrl->handler, struct gspca_dev, ctrl_handler);
        int err = -EINVAL;

        switch (ctrl->id) {
        case V4L2_CID_GAIN:
                err = hdcs_set_gain(gspca_dev, ctrl->val);
                break;
        case V4L2_CID_EXPOSURE:
                err = hdcs_set_exposure(gspca_dev, ctrl->val);
                break;
        }
        return err;
}

static const struct v4l2_ctrl_ops hdcs_ctrl_ops = {
        .s_ctrl = hdcs_s_ctrl,
};

static int hdcs_init_controls(struct sd *sd)
{
        struct v4l2_ctrl_handler *hdl = &sd->gspca_dev.ctrl_handler;

        v4l2_ctrl_handler_init(hdl, 2);
        v4l2_ctrl_new_std(hdl, &hdcs_ctrl_ops,
                        V4L2_CID_EXPOSURE, 0, 0xff, 1, HDCS_DEFAULT_EXPOSURE);
        v4l2_ctrl_new_std(hdl, &hdcs_ctrl_ops,
                        V4L2_CID_GAIN, 0, 0xff, 1, HDCS_DEFAULT_GAIN);
        return hdl->error;
}

static int hdcs_probe_1x00(struct sd *sd)
{
        struct hdcs *hdcs;
        u16 sensor;
        int ret;

        ret = stv06xx_read_sensor(sd, HDCS_IDENT, &sensor);
        if (ret < 0 || sensor != 0x08)
                return -ENODEV;

        pr_info("HDCS-1000/1100 sensor detected\n");

        sd->gspca_dev.cam.cam_mode = hdcs1x00_mode;
        sd->gspca_dev.cam.nmodes = ARRAY_SIZE(hdcs1x00_mode);

        hdcs = kmalloc(sizeof(struct hdcs), GFP_KERNEL);
        if (!hdcs)
                return -ENOMEM;

        hdcs->array.left = 8;
        hdcs->array.top = 8;
        hdcs->array.width = HDCS_1X00_DEF_WIDTH;
        hdcs->array.height = HDCS_1X00_DEF_HEIGHT;
        hdcs->array.border = 4;

        hdcs->exp.cto = 4;
        hdcs->exp.cpo = 2;
        hdcs->exp.rs = 186;
        hdcs->exp.er = 100;

        /*
         * Frame rate on HDCS-1000 with STV600 depends on PSMP:
         *  4 = doesn't work at all
         *  5 = 7.8 fps,
         *  6 = 6.9 fps,
         *  8 = 6.3 fps,
         * 10 = 5.5 fps,
         * 15 = 4.4 fps,
         * 31 = 2.8 fps
         *
         * Frame rate on HDCS-1000 with STV602 depends on PSMP:
         * 15 = doesn't work at all
         * 18 = doesn't work at all
         * 19 = 7.3 fps
         * 20 = 7.4 fps
         * 21 = 7.4 fps
         * 22 = 7.4 fps
         * 24 = 6.3 fps
         * 30 = 5.4 fps
         */
        hdcs->psmp = (sd->bridge == BRIDGE_STV602) ? 20 : 5;

        sd->sensor_priv = hdcs;

        return 0;
}

static int hdcs_probe_1020(struct sd *sd)
{
        struct hdcs *hdcs;
        u16 sensor;
        int ret;

        ret = stv06xx_read_sensor(sd, HDCS_IDENT, &sensor);
        if (ret < 0 || sensor != 0x10)
                return -ENODEV;

        pr_info("HDCS-1020 sensor detected\n");

        sd->gspca_dev.cam.cam_mode = hdcs1020_mode;
        sd->gspca_dev.cam.nmodes = ARRAY_SIZE(hdcs1020_mode);

        hdcs = kmalloc(sizeof(struct hdcs), GFP_KERNEL);
        if (!hdcs)
                return -ENOMEM;

        /*
         * From Andrey's test image: looks like HDCS-1020 upper-left
         * visible pixel is at 24,8 (y maybe even smaller?) and lower-right
         * visible pixel at 375,299 (x maybe even larger?)
         */
        hdcs->array.left = 24;
        hdcs->array.top  = 4;
        hdcs->array.width = HDCS_1020_DEF_WIDTH;
        hdcs->array.height = 304;
        hdcs->array.border = 4;

        hdcs->psmp = 6;

        hdcs->exp.cto = 3;
        hdcs->exp.cpo = 3;
        hdcs->exp.rs = 155;
        hdcs->exp.er = 96;

        sd->sensor_priv = hdcs;

        return 0;
}

static int hdcs_start(struct sd *sd)
{
        struct gspca_dev *gspca_dev = (struct gspca_dev *)sd;

        PDEBUG(D_STREAM, "Starting stream");

        return hdcs_set_state(sd, HDCS_STATE_RUN);
}

static int hdcs_stop(struct sd *sd)
{
        struct gspca_dev *gspca_dev = (struct gspca_dev *)sd;

        PDEBUG(D_STREAM, "Halting stream");

        return hdcs_set_state(sd, HDCS_STATE_SLEEP);
}

static int hdcs_init(struct sd *sd)
{
        struct hdcs *hdcs = sd->sensor_priv;
        int i, err = 0;

        /* Set the STV0602AA in STV0600 emulation mode */
        if (sd->bridge == BRIDGE_STV602)
                stv06xx_write_bridge(sd, STV_STV0600_EMULATION, 1);

        /* Execute the bridge init */
        for (i = 0; i < ARRAY_SIZE(stv_bridge_init) && !err; i++) {
                err = stv06xx_write_bridge(sd, stv_bridge_init[i][0],
                                           stv_bridge_init[i][1]);
        }
        if (err < 0)
                return err;

        /* sensor soft reset */
        hdcs_reset(sd);

        /* Execute the sensor init */
        for (i = 0; i < ARRAY_SIZE(stv_sensor_init) && !err; i++) {
                err = stv06xx_write_sensor(sd, stv_sensor_init[i][0],
                                             stv_sensor_init[i][1]);
        }
        if (err < 0)
                return err;

        /* Enable continuous frame capture, bit 2: stop when frame complete */
        err = stv06xx_write_sensor(sd, HDCS_REG_CONFIG(sd), BIT(3));
        if (err < 0)
                return err;

        /* Set PGA sample duration
        (was 0x7E for the STV602, but caused slow framerate with HDCS-1020) */
        if (IS_1020(sd))
                err = stv06xx_write_sensor(sd, HDCS_TCTRL,
                                (HDCS_ADC_START_SIG_DUR << 6) | hdcs->psmp);
        else
                err = stv06xx_write_sensor(sd, HDCS_TCTRL,
                                (HDCS_ADC_START_SIG_DUR << 5) | hdcs->psmp);
        if (err < 0)
                return err;

        return hdcs_set_size(sd, hdcs->array.width, hdcs->array.height);
}

static int hdcs_dump(struct sd *sd)
{
        u16 reg, val;

        pr_info("Dumping sensor registers:\n");

        for (reg = HDCS_IDENT; reg <= HDCS_ROWEXPH; reg++) {
                stv06xx_read_sensor(sd, reg, &val);
                pr_info("reg 0x%02x = 0x%02x\n", reg, val);
        }
        return 0;
}