// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Syntek STK1135 subdriver
 *
 * Copyright (c) 2013 Ondrej Zary
 *
 * Based on Syntekdriver (stk11xx) by Nicolas VIVIEN:
 *   http://syntekdriver.sourceforge.net
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#define MODULE_NAME "stk1135"

#include "gspca.h"
#include "stk1135.h"

MODULE_AUTHOR("Ondrej Zary");
MODULE_DESCRIPTION("Syntek STK1135 USB Camera Driver");
MODULE_LICENSE("GPL");


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

        u8 pkt_seq;
        u8 sensor_page;

        bool flip_status;
        u8 flip_debounce;

        struct v4l2_ctrl *hflip;
        struct v4l2_ctrl *vflip;
};

static const struct v4l2_pix_format stk1135_modes[] = {
        /* default mode (this driver supports variable resolution) */
        {640, 480, V4L2_PIX_FMT_SBGGR8, V4L2_FIELD_NONE,
                .bytesperline = 640,
                .sizeimage = 640 * 480,
                .colorspace = V4L2_COLORSPACE_SRGB},
};

/* -- read a register -- */
static u8 reg_r(struct gspca_dev *gspca_dev, u16 index)
{
        struct usb_device *dev = gspca_dev->dev;
        int ret;

        if (gspca_dev->usb_err < 0)
                return 0;
        ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
                        0x00,
                        USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                        0x00,
                        index,
                        gspca_dev->usb_buf, 1,
                        500);

        gspca_dbg(gspca_dev, D_USBI, "reg_r 0x%x=0x%02x\n",
                  index, gspca_dev->usb_buf[0]);
        if (ret < 0) {
                pr_err("reg_r 0x%x err %d\n", index, ret);
                gspca_dev->usb_err = ret;
                return 0;
        }

        return gspca_dev->usb_buf[0];
}

/* -- write a register -- */
static void reg_w(struct gspca_dev *gspca_dev, u16 index, u8 val)
{
        int ret;
        struct usb_device *dev = gspca_dev->dev;

        if (gspca_dev->usb_err < 0)
                return;
        ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
                        0x01,
                        USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                        val,
                        index,
                        NULL,
                        0,
                        500);
        gspca_dbg(gspca_dev, D_USBO, "reg_w 0x%x:=0x%02x\n", index, val);
        if (ret < 0) {
                pr_err("reg_w 0x%x err %d\n", index, ret);
                gspca_dev->usb_err = ret;
        }
}

static void reg_w_mask(struct gspca_dev *gspca_dev, u16 index, u8 val, u8 mask)
{
        val = (reg_r(gspca_dev, index) & ~mask) | (val & mask);
        reg_w(gspca_dev, index, val);
}

/* 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 = stk1135_modes;
        gspca_dev->cam.nmodes = ARRAY_SIZE(stk1135_modes);
        return 0;
}

static int stk1135_serial_wait_ready(struct gspca_dev *gspca_dev)
{
        int i = 0;
        u8 val;

        do {
                val = reg_r(gspca_dev, STK1135_REG_SICTL + 1);
                if (i++ > 500) { /* maximum retry count */
                        pr_err("serial bus timeout: status=0x%02x\n", val);
                        return -1;
                }
        /* repeat if BUSY or WRITE/READ not finished */
        } while ((val & 0x10) || !(val & 0x05));

        return 0;
}

static u8 sensor_read_8(struct gspca_dev *gspca_dev, u8 addr)
{
        reg_w(gspca_dev, STK1135_REG_SBUSR, addr);
        /* begin read */
        reg_w(gspca_dev, STK1135_REG_SICTL, 0x20);
        /* wait until finished */
        if (stk1135_serial_wait_ready(gspca_dev)) {
                pr_err("Sensor read failed\n");
                return 0;
        }

        return reg_r(gspca_dev, STK1135_REG_SBUSR + 1);
}

static u16 sensor_read_16(struct gspca_dev *gspca_dev, u8 addr)
{
        return (sensor_read_8(gspca_dev, addr) << 8) |
                sensor_read_8(gspca_dev, 0xf1);
}

static void sensor_write_8(struct gspca_dev *gspca_dev, u8 addr, u8 data)
{
        /* load address and data registers */
        reg_w(gspca_dev, STK1135_REG_SBUSW, addr);
        reg_w(gspca_dev, STK1135_REG_SBUSW + 1, data);
        /* begin write */
        reg_w(gspca_dev, STK1135_REG_SICTL, 0x01);
        /* wait until finished */
        if (stk1135_serial_wait_ready(gspca_dev)) {
                pr_err("Sensor write failed\n");
                return;
        }
}

static void sensor_write_16(struct gspca_dev *gspca_dev, u8 addr, u16 data)
{
        sensor_write_8(gspca_dev, addr, data >> 8);
        sensor_write_8(gspca_dev, 0xf1, data & 0xff);
}

static void sensor_set_page(struct gspca_dev *gspca_dev, u8 page)
{
        struct sd *sd = (struct sd *) gspca_dev;

        if (page != sd->sensor_page) {
                sensor_write_16(gspca_dev, 0xf0, page);
                sd->sensor_page = page;
        }
}

static u16 sensor_read(struct gspca_dev *gspca_dev, u16 reg)
{
        sensor_set_page(gspca_dev, reg >> 8);
        return sensor_read_16(gspca_dev, reg & 0xff);
}

static void sensor_write(struct gspca_dev *gspca_dev, u16 reg, u16 val)
{
        sensor_set_page(gspca_dev, reg >> 8);
        sensor_write_16(gspca_dev, reg & 0xff, val);
}

static void sensor_write_mask(struct gspca_dev *gspca_dev,
                        u16 reg, u16 val, u16 mask)
{
        val = (sensor_read(gspca_dev, reg) & ~mask) | (val & mask);
        sensor_write(gspca_dev, reg, val);
}

struct sensor_val {
        u16 reg;
        u16 val;
};

/* configure MT9M112 sensor */
static void stk1135_configure_mt9m112(struct gspca_dev *gspca_dev)
{
        static const struct sensor_val cfg[] = {
                /* restart&reset, chip enable, reserved */
                { 0x00d, 0x000b }, { 0x00d, 0x0008 }, { 0x035, 0x0022 },
                /* mode ctl: AWB on, AE both, clip aper corr, defect corr, AE */
                { 0x106, 0x700e },

                { 0x2dd, 0x18e0 }, /* B-R thresholds, */

                /* AWB */
                { 0x21f, 0x0180 }, /* Cb and Cr limits */
                { 0x220, 0xc814 }, { 0x221, 0x8080 }, /* lum limits, RGB gain */
                { 0x222, 0xa078 }, { 0x223, 0xa078 }, /* R, B limit */
                { 0x224, 0x5f20 }, { 0x228, 0xea02 }, /* mtx adj lim, adv ctl */
                { 0x229, 0x867a }, /* wide gates */

                /* Color correction */
                /* imager gains base, delta, delta signs */
                { 0x25e, 0x594c }, { 0x25f, 0x4d51 }, { 0x260, 0x0002 },
                /* AWB adv ctl 2, gain offs */
                { 0x2ef, 0x0008 }, { 0x2f2, 0x0000 },
                /* base matrix signs, scale K1-5, K6-9 */
                { 0x202, 0x00ee }, { 0x203, 0x3923 }, { 0x204, 0x0724 },
                /* base matrix coef */
                { 0x209, 0x00cd }, { 0x20a, 0x0093 }, { 0x20b, 0x0004 },/*K1-3*/
                { 0x20c, 0x005c }, { 0x20d, 0x00d9 }, { 0x20e, 0x0053 },/*K4-6*/
                { 0x20f, 0x0008 }, { 0x210, 0x0091 }, { 0x211, 0x00cf },/*K7-9*/
                { 0x215, 0x0000 }, /* delta mtx signs */
                /* delta matrix coef */
                { 0x216, 0x0000 }, { 0x217, 0x0000 }, { 0x218, 0x0000 },/*D1-3*/
                { 0x219, 0x0000 }, { 0x21a, 0x0000 }, { 0x21b, 0x0000 },/*D4-6*/
                { 0x21c, 0x0000 }, { 0x21d, 0x0000 }, { 0x21e, 0x0000 },/*D7-9*/
                /* enable & disable manual WB to apply color corr. settings */
                { 0x106, 0xf00e }, { 0x106, 0x700e },

                /* Lens shading correction */
                { 0x180, 0x0007 }, /* control */
                /* vertical knee 0, 2+1, 4+3 */
                { 0x181, 0xde13 }, { 0x182, 0xebe2 }, { 0x183, 0x00f6 }, /* R */
                { 0x184, 0xe114 }, { 0x185, 0xeadd }, { 0x186, 0xfdf6 }, /* G */
                { 0x187, 0xe511 }, { 0x188, 0xede6 }, { 0x189, 0xfbf7 }, /* B */
                /* horizontal knee 0, 2+1, 4+3, 5 */
                { 0x18a, 0xd613 }, { 0x18b, 0xedec }, /* R .. */
                { 0x18c, 0xf9f2 }, { 0x18d, 0x0000 }, /* .. R */
                { 0x18e, 0xd815 }, { 0x18f, 0xe9ea }, /* G .. */
                { 0x190, 0xf9f1 }, { 0x191, 0x0002 }, /* .. G */
                { 0x192, 0xde10 }, { 0x193, 0xefef }, /* B .. */
                { 0x194, 0xfbf4 }, { 0x195, 0x0002 }, /* .. B */
                /* vertical knee 6+5, 8+7 */
                { 0x1b6, 0x0e06 }, { 0x1b7, 0x2713 }, /* R */
                { 0x1b8, 0x1106 }, { 0x1b9, 0x2713 }, /* G */
                { 0x1ba, 0x0c03 }, { 0x1bb, 0x2a0f }, /* B */
                /* horizontal knee 7+6, 9+8, 10 */
                { 0x1bc, 0x1208 }, { 0x1bd, 0x1a16 }, { 0x1be, 0x0022 }, /* R */
                { 0x1bf, 0x150a }, { 0x1c0, 0x1c1a }, { 0x1c1, 0x002d }, /* G */
                { 0x1c2, 0x1109 }, { 0x1c3, 0x1414 }, { 0x1c4, 0x002a }, /* B */
                { 0x106, 0x740e }, /* enable lens shading correction */

                /* Gamma correction - context A */
                { 0x153, 0x0b03 }, { 0x154, 0x4722 }, { 0x155, 0xac82 },
                { 0x156, 0xdac7 }, { 0x157, 0xf5e9 }, { 0x158, 0xff00 },
                /* Gamma correction - context B */
                { 0x1dc, 0x0b03 }, { 0x1dd, 0x4722 }, { 0x1de, 0xac82 },
                { 0x1df, 0xdac7 }, { 0x1e0, 0xf5e9 }, { 0x1e1, 0xff00 },

                /* output format: RGB, invert output pixclock, output bayer */
                { 0x13a, 0x4300 }, { 0x19b, 0x4300 }, /* for context A, B */
                { 0x108, 0x0180 }, /* format control - enable bayer row flip */

                { 0x22f, 0xd100 }, { 0x29c, 0xd100 }, /* AE A, B */

                /* default prg conf, prg ctl - by 0x2d2, prg advance - PA1 */
                { 0x2d2, 0x0000 }, { 0x2cc, 0x0004 }, { 0x2cb, 0x0001 },

                { 0x22e, 0x0c3c }, { 0x267, 0x1010 }, /* AE tgt ctl, gain lim */

                /* PLL */
                { 0x065, 0xa000 }, /* clk ctl - enable PLL (clear bit 14) */
                { 0x066, 0x2003 }, { 0x067, 0x0501 }, /* PLL M=128, N=3, P=1 */
                { 0x065, 0x2000 }, /* disable PLL bypass (clear bit 15) */

                { 0x005, 0x01b8 }, { 0x007, 0x00d8 }, /* horiz blanking B, A */

                /* AE line size, shutter delay limit */
                { 0x239, 0x06c0 }, { 0x23b, 0x040e }, /* for context A */
                { 0x23a, 0x06c0 }, { 0x23c, 0x0564 }, /* for context B */
                /* shutter width basis 60Hz, 50Hz */
                { 0x257, 0x0208 }, { 0x258, 0x0271 }, /* for context A */
                { 0x259, 0x0209 }, { 0x25a, 0x0271 }, /* for context B */

                { 0x25c, 0x120d }, { 0x25d, 0x1712 }, /* flicker 60Hz, 50Hz */
                { 0x264, 0x5e1c }, /* reserved */
                /* flicker, AE gain limits, gain zone limits */
                { 0x25b, 0x0003 }, { 0x236, 0x7810 }, { 0x237, 0x8304 },

                { 0x008, 0x0021 }, /* vert blanking A */
        };
        int i;
        u16 width, height;

        for (i = 0; i < ARRAY_SIZE(cfg); i++)
                sensor_write(gspca_dev, cfg[i].reg, cfg[i].val);

        /* set output size */
        width = gspca_dev->pixfmt.width;
        height = gspca_dev->pixfmt.height;
        if (width <= 640 && height <= 512) { /* context A (half readout speed)*/
                sensor_write(gspca_dev, 0x1a7, width);
                sensor_write(gspca_dev, 0x1aa, height);
                /* set read mode context A */
                sensor_write(gspca_dev, 0x0c8, 0x0000);
                /* set resize, read mode, vblank, hblank context A */
                sensor_write(gspca_dev, 0x2c8, 0x0000);
        } else { /* context B (full readout speed) */
                sensor_write(gspca_dev, 0x1a1, width);
                sensor_write(gspca_dev, 0x1a4, height);
                /* set read mode context B */
                sensor_write(gspca_dev, 0x0c8, 0x0008);
                /* set resize, read mode, vblank, hblank context B */
                sensor_write(gspca_dev, 0x2c8, 0x040b);
        }
}

static void stk1135_configure_clock(struct gspca_dev *gspca_dev)
{
        /* configure SCLKOUT */
        reg_w(gspca_dev, STK1135_REG_TMGEN, 0x12);
        /* set 1 clock per pixel */
        /* and positive edge clocked pulse high when pixel counter = 0 */
        reg_w(gspca_dev, STK1135_REG_TCP1 + 0, 0x41);
        reg_w(gspca_dev, STK1135_REG_TCP1 + 1, 0x00);
        reg_w(gspca_dev, STK1135_REG_TCP1 + 2, 0x00);
        reg_w(gspca_dev, STK1135_REG_TCP1 + 3, 0x00);

        /* enable CLKOUT for sensor */
        reg_w(gspca_dev, STK1135_REG_SENSO + 0, 0x10);
        /* disable STOP clock */
        reg_w(gspca_dev, STK1135_REG_SENSO + 1, 0x00);
        /* set lower 8 bits of PLL feedback divider */
        reg_w(gspca_dev, STK1135_REG_SENSO + 3, 0x07);
        /* set other PLL parameters */
        reg_w(gspca_dev, STK1135_REG_PLLFD, 0x06);
        /* enable timing generator */
        reg_w(gspca_dev, STK1135_REG_TMGEN, 0x80);
        /* enable PLL */
        reg_w(gspca_dev, STK1135_REG_SENSO + 2, 0x04);

        /* set serial interface clock divider (30MHz/0x1f*16+2) = 60240 kHz) */
        reg_w(gspca_dev, STK1135_REG_SICTL + 2, 0x1f);

        /* wait a while for sensor to catch up */
        udelay(1000);
}

static void stk1135_camera_disable(struct gspca_dev *gspca_dev)
{
        /* set capture end Y position to 0 */
        reg_w(gspca_dev, STK1135_REG_CIEPO + 2, 0x00);
        reg_w(gspca_dev, STK1135_REG_CIEPO + 3, 0x00);
        /* disable capture */
        reg_w_mask(gspca_dev, STK1135_REG_SCTRL, 0x00, 0x80);

        /* enable sensor standby and diasble chip enable */
        sensor_write_mask(gspca_dev, 0x00d, 0x0004, 0x000c);

        /* disable PLL */
        reg_w_mask(gspca_dev, STK1135_REG_SENSO + 2, 0x00, 0x01);
        /* disable timing generator */
        reg_w(gspca_dev, STK1135_REG_TMGEN, 0x00);
        /* enable STOP clock */
        reg_w(gspca_dev, STK1135_REG_SENSO + 1, 0x20);
        /* disable CLKOUT for sensor */
        reg_w(gspca_dev, STK1135_REG_SENSO, 0x00);

        /* disable sensor (GPIO5) and enable GPIO0,3,6 (?) - sensor standby? */
        reg_w(gspca_dev, STK1135_REG_GCTRL, 0x49);
}

/* this function is called at probe and resume time */
static int sd_init(struct gspca_dev *gspca_dev)
{
        u16 sensor_id;
        char *sensor_name;
        struct sd *sd = (struct sd *) gspca_dev;

        /* set GPIO3,4,5,6 direction to output */
        reg_w(gspca_dev, STK1135_REG_GCTRL + 2, 0x78);
        /* enable sensor (GPIO5) */
        reg_w(gspca_dev, STK1135_REG_GCTRL, (1 << 5));
        /* disable ROM interface */
        reg_w(gspca_dev, STK1135_REG_GCTRL + 3, 0x80);
        /* enable interrupts from GPIO8 (flip sensor) and GPIO9 (???) */
        reg_w(gspca_dev, STK1135_REG_ICTRL + 1, 0x00);
        reg_w(gspca_dev, STK1135_REG_ICTRL + 3, 0x03);
        /* enable remote wakeup from GPIO9 (???) */
        reg_w(gspca_dev, STK1135_REG_RMCTL + 1, 0x00);
        reg_w(gspca_dev, STK1135_REG_RMCTL + 3, 0x02);

        /* reset serial interface */
        reg_w(gspca_dev, STK1135_REG_SICTL, 0x80);
        reg_w(gspca_dev, STK1135_REG_SICTL, 0x00);
        /* set sensor address */
        reg_w(gspca_dev, STK1135_REG_SICTL + 3, 0xba);
        /* disable alt 2-wire serial interface */
        reg_w(gspca_dev, STK1135_REG_ASIC + 3, 0x00);

        stk1135_configure_clock(gspca_dev);

        /* read sensor ID */
        sd->sensor_page = 0xff;
        sensor_id = sensor_read(gspca_dev, 0x000);

        switch (sensor_id) {
        case 0x148c:
                sensor_name = "MT9M112";
                break;
        default:
                sensor_name = "unknown";
        }
        pr_info("Detected sensor type %s (0x%x)\n", sensor_name, sensor_id);

        stk1135_camera_disable(gspca_dev);

        return gspca_dev->usb_err;
}

/* -- start the camera -- */
static int sd_start(struct gspca_dev *gspca_dev)
{
        struct sd *sd = (struct sd *) gspca_dev;
        u16 width, height;

        /* enable sensor (GPIO5) */
        reg_w(gspca_dev, STK1135_REG_GCTRL, (1 << 5));

        stk1135_configure_clock(gspca_dev);

        /* set capture start position X = 0, Y = 0 */
        reg_w(gspca_dev, STK1135_REG_CISPO + 0, 0x00);
        reg_w(gspca_dev, STK1135_REG_CISPO + 1, 0x00);
        reg_w(gspca_dev, STK1135_REG_CISPO + 2, 0x00);
        reg_w(gspca_dev, STK1135_REG_CISPO + 3, 0x00);

        /* set capture end position */
        width = gspca_dev->pixfmt.width;
        height = gspca_dev->pixfmt.height;
        reg_w(gspca_dev, STK1135_REG_CIEPO + 0, width & 0xff);
        reg_w(gspca_dev, STK1135_REG_CIEPO + 1, width >> 8);
        reg_w(gspca_dev, STK1135_REG_CIEPO + 2, height & 0xff);
        reg_w(gspca_dev, STK1135_REG_CIEPO + 3, height >> 8);

        /* set 8-bit mode */
        reg_w(gspca_dev, STK1135_REG_SCTRL, 0x20);

        stk1135_configure_mt9m112(gspca_dev);

        /* enable capture */
        reg_w_mask(gspca_dev, STK1135_REG_SCTRL, 0x80, 0x80);

        if (gspca_dev->usb_err >= 0)
                gspca_dbg(gspca_dev, D_STREAM, "camera started alt: 0x%02x\n",
                          gspca_dev->alt);

        sd->pkt_seq = 0;

        return gspca_dev->usb_err;
}

static void sd_stopN(struct gspca_dev *gspca_dev)
{
        struct usb_device *dev = gspca_dev->dev;

        usb_set_interface(dev, gspca_dev->iface, 0);

        stk1135_camera_disable(gspca_dev);

        gspca_dbg(gspca_dev, D_STREAM, "camera stopped\n");
}

static void sd_pkt_scan(struct gspca_dev *gspca_dev,
                        u8 *data,                       /* isoc packet */
                        int len)                        /* iso packet length */
{
        struct sd *sd = (struct sd *) gspca_dev;
        int skip = sizeof(struct stk1135_pkt_header);
        bool flip;
        enum gspca_packet_type pkt_type = INTER_PACKET;
        struct stk1135_pkt_header *hdr = (void *)data;
        u8 seq;

        if (len < 4) {
                gspca_dbg(gspca_dev, D_PACK, "received short packet (less than 4 bytes)\n");
                return;
        }

        /* GPIO 8 is flip sensor (1 = normal position, 0 = flipped to back) */
        flip = !(le16_to_cpu(hdr->gpio) & (1 << 8));
        /* it's a switch, needs software debounce */
        if (sd->flip_status != flip)
                sd->flip_debounce++;
        else
                sd->flip_debounce = 0;

        /* check sequence number (not present in new frame packets) */
        if (!(hdr->flags & STK1135_HDR_FRAME_START)) {
                seq = hdr->seq & STK1135_HDR_SEQ_MASK;
                if (seq != sd->pkt_seq) {
                        gspca_dbg(gspca_dev, D_PACK, "received out-of-sequence packet\n");
                        /* resync sequence and discard packet */
                        sd->pkt_seq = seq;
                        gspca_dev->last_packet_type = DISCARD_PACKET;
                        return;
                }
        }
        sd->pkt_seq++;
        if (sd->pkt_seq > STK1135_HDR_SEQ_MASK)
                sd->pkt_seq = 0;

        if (len == sizeof(struct stk1135_pkt_header))
                return;

        if (hdr->flags & STK1135_HDR_FRAME_START) { /* new frame */
                skip = 8;       /* the header is longer */
                gspca_frame_add(gspca_dev, LAST_PACKET, data, 0);
                pkt_type = FIRST_PACKET;
        }
        gspca_frame_add(gspca_dev, pkt_type, data + skip, len - skip);
}

static void sethflip(struct gspca_dev *gspca_dev, s32 val)
{
        struct sd *sd = (struct sd *) gspca_dev;

        if (sd->flip_status)
                val = !val;
        sensor_write_mask(gspca_dev, 0x020, val ? 0x0002 : 0x0000 , 0x0002);
}

static void setvflip(struct gspca_dev *gspca_dev, s32 val)
{
        struct sd *sd = (struct sd *) gspca_dev;

        if (sd->flip_status)
                val = !val;
        sensor_write_mask(gspca_dev, 0x020, val ? 0x0001 : 0x0000 , 0x0001);
}

static void stk1135_dq_callback(struct gspca_dev *gspca_dev)
{
        struct sd *sd = (struct sd *) gspca_dev;

        if (sd->flip_debounce > 100) {
                sd->flip_status = !sd->flip_status;
                sethflip(gspca_dev, v4l2_ctrl_g_ctrl(sd->hflip));
                setvflip(gspca_dev, v4l2_ctrl_g_ctrl(sd->vflip));
        }
}

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

        gspca_dev->usb_err = 0;

        if (!gspca_dev->streaming)
                return 0;

        switch (ctrl->id) {
        case V4L2_CID_HFLIP:
                sethflip(gspca_dev, ctrl->val);
                break;
        case V4L2_CID_VFLIP:
                setvflip(gspca_dev, ctrl->val);
                break;
        }

        return gspca_dev->usb_err;
}

static const struct v4l2_ctrl_ops sd_ctrl_ops = {
        .s_ctrl = sd_s_ctrl,
};

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

        gspca_dev->vdev.ctrl_handler = hdl;
        v4l2_ctrl_handler_init(hdl, 2);
        sd->hflip = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
                        V4L2_CID_HFLIP, 0, 1, 1, 0);
        sd->vflip = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
                        V4L2_CID_VFLIP, 0, 1, 1, 0);

        if (hdl->error) {
                pr_err("Could not initialize controls\n");
                return hdl->error;
        }
        return 0;
}

static void stk1135_try_fmt(struct gspca_dev *gspca_dev, struct v4l2_format *fmt)
{
        fmt->fmt.pix.width = clamp(fmt->fmt.pix.width, 32U, 1280U);
        fmt->fmt.pix.height = clamp(fmt->fmt.pix.height, 32U, 1024U);
        /* round up to even numbers */
        fmt->fmt.pix.width += (fmt->fmt.pix.width & 1);
        fmt->fmt.pix.height += (fmt->fmt.pix.height & 1);

        fmt->fmt.pix.bytesperline = fmt->fmt.pix.width;
        fmt->fmt.pix.sizeimage = fmt->fmt.pix.width * fmt->fmt.pix.height;
}

static int stk1135_enum_framesizes(struct gspca_dev *gspca_dev,
                        struct v4l2_frmsizeenum *fsize)
{
        if (fsize->index != 0 || fsize->pixel_format != V4L2_PIX_FMT_SBGGR8)
                return -EINVAL;

        fsize->type = V4L2_FRMSIZE_TYPE_STEPWISE;
        fsize->stepwise.min_width = 32;
        fsize->stepwise.min_height = 32;
        fsize->stepwise.max_width = 1280;
        fsize->stepwise.max_height = 1024;
        fsize->stepwise.step_width = 2;
        fsize->stepwise.step_height = 2;

        return 0;
}

/* sub-driver description */
static const struct sd_desc sd_desc = {
        .name = MODULE_NAME,
        .config = sd_config,
        .init = sd_init,
        .init_controls = sd_init_controls,
        .start = sd_start,
        .stopN = sd_stopN,
        .pkt_scan = sd_pkt_scan,
        .dq_callback = stk1135_dq_callback,
        .try_fmt = stk1135_try_fmt,
        .enum_framesizes = stk1135_enum_framesizes,
};

/* -- module initialisation -- */
static const struct usb_device_id device_table[] = {
        {USB_DEVICE(0x174f, 0x6a31)},   /* ASUS laptop, MT9M112 sensor */
        {}
};
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);