Added missing tegra files.HEADmaster

1 files changed, 933 insertions, 0 deletions

diff --git a/drivers/media/video/mt9t031.c b/drivers/media/video/mt9t031.c
new file mode 100644
index 00000000000..30547cc3f89
--- /dev/null
+++ b/drivers/media/video/mt9t031.c
@@ -0,0 +1,933 @@
+/*
+ * Driver for MT9T031 CMOS Image Sensor from Micron
+ *
+ * Copyright (C) 2008, Guennadi Liakhovetski, DENX Software Engineering <lg@denx.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/log2.h>
+#include <linux/pm.h>
+#include <linux/slab.h>
+#include <linux/videodev2.h>
+
+#include <media/soc_camera.h>
+#include <media/v4l2-chip-ident.h>
+#include <media/v4l2-subdev.h>
+
+/*
+ * mt9t031 i2c address 0x5d
+ * The platform has to define i2c_board_info and link to it from
+ * struct soc_camera_link
+ */
+
+/* mt9t031 selected register addresses */
+#define MT9T031_CHIP_VERSION            0x00
+#define MT9T031_ROW_START               0x01
+#define MT9T031_COLUMN_START            0x02
+#define MT9T031_WINDOW_HEIGHT           0x03
+#define MT9T031_WINDOW_WIDTH            0x04
+#define MT9T031_HORIZONTAL_BLANKING     0x05
+#define MT9T031_VERTICAL_BLANKING       0x06
+#define MT9T031_OUTPUT_CONTROL          0x07
+#define MT9T031_SHUTTER_WIDTH_UPPER     0x08
+#define MT9T031_SHUTTER_WIDTH           0x09
+#define MT9T031_PIXEL_CLOCK_CONTROL     0x0a
+#define MT9T031_FRAME_RESTART           0x0b
+#define MT9T031_SHUTTER_DELAY           0x0c
+#define MT9T031_RESET                   0x0d
+#define MT9T031_READ_MODE_1             0x1e
+#define MT9T031_READ_MODE_2             0x20
+#define MT9T031_READ_MODE_3             0x21
+#define MT9T031_ROW_ADDRESS_MODE        0x22
+#define MT9T031_COLUMN_ADDRESS_MODE     0x23
+#define MT9T031_GLOBAL_GAIN             0x35
+#define MT9T031_CHIP_ENABLE             0xF8
+
+#define MT9T031_MAX_HEIGHT              1536
+#define MT9T031_MAX_WIDTH               2048
+#define MT9T031_MIN_HEIGHT              2
+#define MT9T031_MIN_WIDTH               18
+#define MT9T031_HORIZONTAL_BLANK        142
+#define MT9T031_VERTICAL_BLANK          25
+#define MT9T031_COLUMN_SKIP             32
+#define MT9T031_ROW_SKIP                20
+
+#define MT9T031_BUS_PARAM       (SOCAM_PCLK_SAMPLE_RISING |     \
+        SOCAM_PCLK_SAMPLE_FALLING | SOCAM_HSYNC_ACTIVE_HIGH |   \
+        SOCAM_VSYNC_ACTIVE_HIGH | SOCAM_DATA_ACTIVE_HIGH |      \
+        SOCAM_MASTER | SOCAM_DATAWIDTH_10)
+
+struct mt9t031 {
+        struct v4l2_subdev subdev;
+        struct v4l2_rect rect;  /* Sensor window */
+        int model;      /* V4L2_IDENT_MT9T031* codes from v4l2-chip-ident.h */
+        u16 xskip;
+        u16 yskip;
+        unsigned int gain;
+        unsigned short y_skip_top;      /* Lines to skip at the top */
+        unsigned int exposure;
+        unsigned char autoexposure;
+};
+
+static struct mt9t031 *to_mt9t031(const struct i2c_client *client)
+{
+        return container_of(i2c_get_clientdata(client), struct mt9t031, subdev);
+}
+
+static int reg_read(struct i2c_client *client, const u8 reg)
+{
+        s32 data = i2c_smbus_read_word_data(client, reg);
+        return data < 0 ? data : swab16(data);
+}
+
+static int reg_write(struct i2c_client *client, const u8 reg,
+                     const u16 data)
+{
+        return i2c_smbus_write_word_data(client, reg, swab16(data));
+}
+
+static int reg_set(struct i2c_client *client, const u8 reg,
+                   const u16 data)
+{
+        int ret;
+
+        ret = reg_read(client, reg);
+        if (ret < 0)
+                return ret;
+        return reg_write(client, reg, ret | data);
+}
+
+static int reg_clear(struct i2c_client *client, const u8 reg,
+                     const u16 data)
+{
+        int ret;
+
+        ret = reg_read(client, reg);
+        if (ret < 0)
+                return ret;
+        return reg_write(client, reg, ret & ~data);
+}
+
+static int set_shutter(struct i2c_client *client, const u32 data)
+{
+        int ret;
+
+        ret = reg_write(client, MT9T031_SHUTTER_WIDTH_UPPER, data >> 16);
+
+        if (ret >= 0)
+                ret = reg_write(client, MT9T031_SHUTTER_WIDTH, data & 0xffff);
+
+        return ret;
+}
+
+static int get_shutter(struct i2c_client *client, u32 *data)
+{
+        int ret;
+
+        ret = reg_read(client, MT9T031_SHUTTER_WIDTH_UPPER);
+        *data = ret << 16;
+
+        if (ret >= 0)
+                ret = reg_read(client, MT9T031_SHUTTER_WIDTH);
+        *data |= ret & 0xffff;
+
+        return ret < 0 ? ret : 0;
+}
+
+static int mt9t031_idle(struct i2c_client *client)
+{
+        int ret;
+
+        /* Disable chip output, synchronous option update */
+        ret = reg_write(client, MT9T031_RESET, 1);
+        if (ret >= 0)
+                ret = reg_write(client, MT9T031_RESET, 0);
+        if (ret >= 0)
+                ret = reg_clear(client, MT9T031_OUTPUT_CONTROL, 2);
+
+        return ret >= 0 ? 0 : -EIO;
+}
+
+static int mt9t031_disable(struct i2c_client *client)
+{
+        /* Disable the chip */
+        reg_clear(client, MT9T031_OUTPUT_CONTROL, 2);
+
+        return 0;
+}
+
+static int mt9t031_s_stream(struct v4l2_subdev *sd, int enable)
+{
+        struct i2c_client *client = v4l2_get_subdevdata(sd);
+        int ret;
+
+        if (enable)
+                /* Switch to master "normal" mode */
+                ret = reg_set(client, MT9T031_OUTPUT_CONTROL, 2);
+        else
+                /* Stop sensor readout */
+                ret = reg_clear(client, MT9T031_OUTPUT_CONTROL, 2);
+
+        if (ret < 0)
+                return -EIO;
+
+        return 0;
+}
+
+static int mt9t031_set_bus_param(struct soc_camera_device *icd,
+                                 unsigned long flags)
+{
+        struct i2c_client *client = to_i2c_client(to_soc_camera_control(icd));
+
+        /* The caller should have queried our parameters, check anyway */
+        if (flags & ~MT9T031_BUS_PARAM)
+                return -EINVAL;
+
+        if (flags & SOCAM_PCLK_SAMPLE_FALLING)
+                reg_clear(client, MT9T031_PIXEL_CLOCK_CONTROL, 0x8000);
+        else
+                reg_set(client, MT9T031_PIXEL_CLOCK_CONTROL, 0x8000);
+
+        return 0;
+}
+
+static unsigned long mt9t031_query_bus_param(struct soc_camera_device *icd)
+{
+        struct soc_camera_link *icl = to_soc_camera_link(icd);
+
+        return soc_camera_apply_sensor_flags(icl, MT9T031_BUS_PARAM);
+}
+
+enum {
+        MT9T031_CTRL_VFLIP,
+        MT9T031_CTRL_HFLIP,
+        MT9T031_CTRL_GAIN,
+        MT9T031_CTRL_EXPOSURE,
+        MT9T031_CTRL_EXPOSURE_AUTO,
+};
+
+static const struct v4l2_queryctrl mt9t031_controls[] = {
+        [MT9T031_CTRL_VFLIP] = {
+                .id             = V4L2_CID_VFLIP,
+                .type           = V4L2_CTRL_TYPE_BOOLEAN,
+                .name           = "Flip Vertically",
+                .minimum        = 0,
+                .maximum        = 1,
+                .step           = 1,
+                .default_value  = 0,
+        },
+        [MT9T031_CTRL_HFLIP] = {
+                .id             = V4L2_CID_HFLIP,
+                .type           = V4L2_CTRL_TYPE_BOOLEAN,
+                .name           = "Flip Horizontally",
+                .minimum        = 0,
+                .maximum        = 1,
+                .step           = 1,
+                .default_value  = 0,
+        },
+        [MT9T031_CTRL_GAIN] = {
+                .id             = V4L2_CID_GAIN,
+                .type           = V4L2_CTRL_TYPE_INTEGER,
+                .name           = "Gain",
+                .minimum        = 0,
+                .maximum        = 127,
+                .step           = 1,
+                .default_value  = 64,
+                .flags          = V4L2_CTRL_FLAG_SLIDER,
+        },
+        [MT9T031_CTRL_EXPOSURE] = {
+                .id             = V4L2_CID_EXPOSURE,
+                .type           = V4L2_CTRL_TYPE_INTEGER,
+                .name           = "Exposure",
+                .minimum        = 1,
+                .maximum        = 255,
+                .step           = 1,
+                .default_value  = 255,
+                .flags          = V4L2_CTRL_FLAG_SLIDER,
+        },
+        [MT9T031_CTRL_EXPOSURE_AUTO] = {
+                .id             = V4L2_CID_EXPOSURE_AUTO,
+                .type           = V4L2_CTRL_TYPE_BOOLEAN,
+                .name           = "Automatic Exposure",
+                .minimum        = 0,
+                .maximum        = 1,
+                .step           = 1,
+                .default_value  = 1,
+        }
+};
+
+static struct soc_camera_ops mt9t031_ops = {
+        .set_bus_param          = mt9t031_set_bus_param,
+        .query_bus_param        = mt9t031_query_bus_param,
+        .controls               = mt9t031_controls,
+        .num_controls           = ARRAY_SIZE(mt9t031_controls),
+};
+
+/* target must be _even_ */
+static u16 mt9t031_skip(s32 *source, s32 target, s32 max)
+{
+        unsigned int skip;
+
+        if (*source < target + target / 2) {
+                *source = target;
+                return 1;
+        }
+
+        skip = min(max, *source + target / 2) / target;
+        if (skip > 8)
+                skip = 8;
+        *source = target * skip;
+
+        return skip;
+}
+
+/* rect is the sensor rectangle, the caller guarantees parameter validity */
+static int mt9t031_set_params(struct i2c_client *client,
+                              struct v4l2_rect *rect, u16 xskip, u16 yskip)
+{
+        struct mt9t031 *mt9t031 = to_mt9t031(client);
+        int ret;
+        u16 xbin, ybin;
+        const u16 hblank = MT9T031_HORIZONTAL_BLANK,
+                vblank = MT9T031_VERTICAL_BLANK;
+
+        xbin = min(xskip, (u16)3);
+        ybin = min(yskip, (u16)3);
+
+        /*
+         * Could just do roundup(rect->left, [xy]bin * 2); but this is cheaper.
+         * There is always a valid suitably aligned value. The worst case is
+         * xbin = 3, width = 2048. Then we will start at 36, the last read out
+         * pixel will be 2083, which is < 2085 - first black pixel.
+         *
+         * MT9T031 datasheet imposes window left border alignment, depending on
+         * the selected xskip. Failing to conform to this requirement produces
+         * dark horizontal stripes in the image. However, even obeying to this
+         * requirement doesn't eliminate the stripes in all configurations. They
+         * appear "locally reproducibly," but can differ between tests under
+         * different lighting conditions.
+         */
+        switch (xbin) {
+        case 1:
+                rect->left &= ~1;
+                break;
+        case 2:
+                rect->left &= ~3;
+                break;
+        case 3:
+                rect->left = rect->left > roundup(MT9T031_COLUMN_SKIP, 6) ?
+                        (rect->left / 6) * 6 : roundup(MT9T031_COLUMN_SKIP, 6);
+        }
+
+        rect->top &= ~1;
+
+        dev_dbg(&client->dev, "skip %u:%u, rect %ux%u@%u:%u\n",
+                xskip, yskip, rect->width, rect->height, rect->left, rect->top);
+
+        /* Disable register update, reconfigure atomically */
+        ret = reg_set(client, MT9T031_OUTPUT_CONTROL, 1);
+        if (ret < 0)
+                return ret;
+
+        /* Blanking and start values - default... */
+        ret = reg_write(client, MT9T031_HORIZONTAL_BLANKING, hblank);
+        if (ret >= 0)
+                ret = reg_write(client, MT9T031_VERTICAL_BLANKING, vblank);
+
+        if (yskip != mt9t031->yskip || xskip != mt9t031->xskip) {
+                /* Binning, skipping */
+                if (ret >= 0)
+                        ret = reg_write(client, MT9T031_COLUMN_ADDRESS_MODE,
+                                        ((xbin - 1) << 4) | (xskip - 1));
+                if (ret >= 0)
+                        ret = reg_write(client, MT9T031_ROW_ADDRESS_MODE,
+                                        ((ybin - 1) << 4) | (yskip - 1));
+        }
+        dev_dbg(&client->dev, "new physical left %u, top %u\n",
+                rect->left, rect->top);
+
+        /*
+         * The caller provides a supported format, as guaranteed by
+         * icd->try_fmt_cap(), soc_camera_s_crop() and soc_camera_cropcap()
+         */
+        if (ret >= 0)
+                ret = reg_write(client, MT9T031_COLUMN_START, rect->left);
+        if (ret >= 0)
+                ret = reg_write(client, MT9T031_ROW_START, rect->top);
+        if (ret >= 0)
+                ret = reg_write(client, MT9T031_WINDOW_WIDTH, rect->width - 1);
+        if (ret >= 0)
+                ret = reg_write(client, MT9T031_WINDOW_HEIGHT,
+                                rect->height + mt9t031->y_skip_top - 1);
+        if (ret >= 0 && mt9t031->autoexposure) {
+                unsigned int total_h = rect->height + mt9t031->y_skip_top + vblank;
+                ret = set_shutter(client, total_h);
+                if (ret >= 0) {
+                        const u32 shutter_max = MT9T031_MAX_HEIGHT + vblank;
+                        const struct v4l2_queryctrl *qctrl =
+                                &mt9t031_controls[MT9T031_CTRL_EXPOSURE];
+                        mt9t031->exposure = (shutter_max / 2 + (total_h - 1) *
+                                 (qctrl->maximum - qctrl->minimum)) /
+                                shutter_max + qctrl->minimum;
+                }
+        }
+
+        /* Re-enable register update, commit all changes */
+        if (ret >= 0)
+                ret = reg_clear(client, MT9T031_OUTPUT_CONTROL, 1);
+
+        if (ret >= 0) {
+                mt9t031->rect = *rect;
+                mt9t031->xskip = xskip;
+                mt9t031->yskip = yskip;
+        }
+
+        return ret < 0 ? ret : 0;
+}
+
+static int mt9t031_s_crop(struct v4l2_subdev *sd, struct v4l2_crop *a)
+{
+        struct v4l2_rect rect = a->c;
+        struct i2c_client *client = v4l2_get_subdevdata(sd);
+        struct mt9t031 *mt9t031 = to_mt9t031(client);
+
+        rect.width = ALIGN(rect.width, 2);
+        rect.height = ALIGN(rect.height, 2);
+
+        soc_camera_limit_side(&rect.left, &rect.width,
+                     MT9T031_COLUMN_SKIP, MT9T031_MIN_WIDTH, MT9T031_MAX_WIDTH);
+
+        soc_camera_limit_side(&rect.top, &rect.height,
+                     MT9T031_ROW_SKIP, MT9T031_MIN_HEIGHT, MT9T031_MAX_HEIGHT);
+
+        return mt9t031_set_params(client, &rect, mt9t031->xskip, mt9t031->yskip);
+}
+
+static int mt9t031_g_crop(struct v4l2_subdev *sd, struct v4l2_crop *a)
+{
+        struct i2c_client *client = v4l2_get_subdevdata(sd);
+        struct mt9t031 *mt9t031 = to_mt9t031(client);
+
+        a->c    = mt9t031->rect;
+        a->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+
+        return 0;
+}
+
+static int mt9t031_cropcap(struct v4l2_subdev *sd, struct v4l2_cropcap *a)
+{
+        a->bounds.left                  = MT9T031_COLUMN_SKIP;
+        a->bounds.top                   = MT9T031_ROW_SKIP;
+        a->bounds.width                 = MT9T031_MAX_WIDTH;
+        a->bounds.height                = MT9T031_MAX_HEIGHT;
+        a->defrect                      = a->bounds;
+        a->type                         = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+        a->pixelaspect.numerator        = 1;
+        a->pixelaspect.denominator      = 1;
+
+        return 0;
+}
+
+static int mt9t031_g_fmt(struct v4l2_subdev *sd,
+                         struct v4l2_mbus_framefmt *mf)
+{
+        struct i2c_client *client = v4l2_get_subdevdata(sd);
+        struct mt9t031 *mt9t031 = to_mt9t031(client);
+
+        mf->width       = mt9t031->rect.width / mt9t031->xskip;
+        mf->height      = mt9t031->rect.height / mt9t031->yskip;
+        mf->code        = V4L2_MBUS_FMT_SBGGR10_1X10;
+        mf->colorspace  = V4L2_COLORSPACE_SRGB;
+        mf->field       = V4L2_FIELD_NONE;
+
+        return 0;
+}
+
+static int mt9t031_s_fmt(struct v4l2_subdev *sd,
+                         struct v4l2_mbus_framefmt *mf)
+{
+        struct i2c_client *client = v4l2_get_subdevdata(sd);
+        struct mt9t031 *mt9t031 = to_mt9t031(client);
+        u16 xskip, yskip;
+        struct v4l2_rect rect = mt9t031->rect;
+
+        /*
+         * try_fmt has put width and height within limits.
+         * S_FMT: use binning and skipping for scaling
+         */
+        xskip = mt9t031_skip(&rect.width, mf->width, MT9T031_MAX_WIDTH);
+        yskip = mt9t031_skip(&rect.height, mf->height, MT9T031_MAX_HEIGHT);
+
+        mf->code        = V4L2_MBUS_FMT_SBGGR10_1X10;
+        mf->colorspace  = V4L2_COLORSPACE_SRGB;
+
+        /* mt9t031_set_params() doesn't change width and height */
+        return mt9t031_set_params(client, &rect, xskip, yskip);
+}
+
+/*
+ * If a user window larger than sensor window is requested, we'll increase the
+ * sensor window.
+ */
+static int mt9t031_try_fmt(struct v4l2_subdev *sd,
+                           struct v4l2_mbus_framefmt *mf)
+{
+        v4l_bound_align_image(
+                &mf->width, MT9T031_MIN_WIDTH, MT9T031_MAX_WIDTH, 1,
+                &mf->height, MT9T031_MIN_HEIGHT, MT9T031_MAX_HEIGHT, 1, 0);
+
+        mf->code        = V4L2_MBUS_FMT_SBGGR10_1X10;
+        mf->colorspace  = V4L2_COLORSPACE_SRGB;
+
+        return 0;
+}
+
+static int mt9t031_g_chip_ident(struct v4l2_subdev *sd,
+                                struct v4l2_dbg_chip_ident *id)
+{
+        struct i2c_client *client = v4l2_get_subdevdata(sd);
+        struct mt9t031 *mt9t031 = to_mt9t031(client);
+
+        if (id->match.type != V4L2_CHIP_MATCH_I2C_ADDR)
+                return -EINVAL;
+
+        if (id->match.addr != client->addr)
+                return -ENODEV;
+
+        id->ident       = mt9t031->model;
+        id->revision    = 0;
+
+        return 0;
+}
+
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+static int mt9t031_g_register(struct v4l2_subdev *sd,
+                              struct v4l2_dbg_register *reg)
+{
+        struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+        if (reg->match.type != V4L2_CHIP_MATCH_I2C_ADDR || reg->reg > 0xff)
+                return -EINVAL;
+
+        if (reg->match.addr != client->addr)
+                return -ENODEV;
+
+        reg->val = reg_read(client, reg->reg);
+
+        if (reg->val > 0xffff)
+                return -EIO;
+
+        return 0;
+}
+
+static int mt9t031_s_register(struct v4l2_subdev *sd,
+                              struct v4l2_dbg_register *reg)
+{
+        struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+        if (reg->match.type != V4L2_CHIP_MATCH_I2C_ADDR || reg->reg > 0xff)
+                return -EINVAL;
+
+        if (reg->match.addr != client->addr)
+                return -ENODEV;
+
+        if (reg_write(client, reg->reg, reg->val) < 0)
+                return -EIO;
+
+        return 0;
+}
+#endif
+
+static int mt9t031_g_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl)
+{
+        struct i2c_client *client = v4l2_get_subdevdata(sd);
+        struct mt9t031 *mt9t031 = to_mt9t031(client);
+        int data;
+
+        switch (ctrl->id) {
+        case V4L2_CID_VFLIP:
+                data = reg_read(client, MT9T031_READ_MODE_2);
+                if (data < 0)
+                        return -EIO;
+                ctrl->value = !!(data & 0x8000);
+                break;
+        case V4L2_CID_HFLIP:
+                data = reg_read(client, MT9T031_READ_MODE_2);
+                if (data < 0)
+                        return -EIO;
+                ctrl->value = !!(data & 0x4000);
+                break;
+        case V4L2_CID_EXPOSURE_AUTO:
+                ctrl->value = mt9t031->autoexposure;
+                break;
+        case V4L2_CID_GAIN:
+                ctrl->value = mt9t031->gain;
+                break;
+        case V4L2_CID_EXPOSURE:
+                ctrl->value = mt9t031->exposure;
+                break;
+        }
+        return 0;
+}
+
+static int mt9t031_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl)
+{
+        struct i2c_client *client = v4l2_get_subdevdata(sd);
+        struct mt9t031 *mt9t031 = to_mt9t031(client);
+        const struct v4l2_queryctrl *qctrl;
+        int data;
+
+        switch (ctrl->id) {
+        case V4L2_CID_VFLIP:
+                if (ctrl->value)
+                        data = reg_set(client, MT9T031_READ_MODE_2, 0x8000);
+                else
+                        data = reg_clear(client, MT9T031_READ_MODE_2, 0x8000);
+                if (data < 0)
+                        return -EIO;
+                break;
+        case V4L2_CID_HFLIP:
+                if (ctrl->value)
+                        data = reg_set(client, MT9T031_READ_MODE_2, 0x4000);
+                else
+                        data = reg_clear(client, MT9T031_READ_MODE_2, 0x4000);
+                if (data < 0)
+                        return -EIO;
+                break;
+        case V4L2_CID_GAIN:
+                qctrl = &mt9t031_controls[MT9T031_CTRL_GAIN];
+                if (ctrl->value > qctrl->maximum || ctrl->value < qctrl->minimum)
+                        return -EINVAL;
+                /* See Datasheet Table 7, Gain settings. */
+                if (ctrl->value <= qctrl->default_value) {
+                        /* Pack it into 0..1 step 0.125, register values 0..8 */
+                        unsigned long range = qctrl->default_value - qctrl->minimum;
+                        data = ((ctrl->value - qctrl->minimum) * 8 + range / 2) / range;
+
+                        dev_dbg(&client->dev, "Setting gain %d\n", data);
+                        data = reg_write(client, MT9T031_GLOBAL_GAIN, data);
+                        if (data < 0)
+                                return -EIO;
+                } else {
+                        /* Pack it into 1.125..128 variable step, register values 9..0x7860 */
+                        /* We assume qctrl->maximum - qctrl->default_value - 1 > 0 */
+                        unsigned long range = qctrl->maximum - qctrl->default_value - 1;
+                        /* calculated gain: map 65..127 to 9..1024 step 0.125 */
+                        unsigned long gain = ((ctrl->value - qctrl->default_value - 1) *
+                                               1015 + range / 2) / range + 9;
+
+                        if (gain <= 32)         /* calculated gain 9..32 -> 9..32 */
+                                data = gain;
+                        else if (gain <= 64)    /* calculated gain 33..64 -> 0x51..0x60 */
+                                data = ((gain - 32) * 16 + 16) / 32 + 80;
+                        else
+                                /* calculated gain 65..1024 -> (1..120) << 8 + 0x60 */
+                                data = (((gain - 64 + 7) * 32) & 0xff00) | 0x60;
+
+                        dev_dbg(&client->dev, "Set gain from 0x%x to 0x%x\n",
+                                reg_read(client, MT9T031_GLOBAL_GAIN), data);
+                        data = reg_write(client, MT9T031_GLOBAL_GAIN, data);
+                        if (data < 0)
+                                return -EIO;
+                }
+
+                /* Success */
+                mt9t031->gain = ctrl->value;
+                break;
+        case V4L2_CID_EXPOSURE:
+                qctrl = &mt9t031_controls[MT9T031_CTRL_EXPOSURE];
+                /* mt9t031 has maximum == default */
+                if (ctrl->value > qctrl->maximum || ctrl->value < qctrl->minimum)
+                        return -EINVAL;
+                else {
+                        const unsigned long range = qctrl->maximum - qctrl->minimum;
+                        const u32 shutter = ((ctrl->value - qctrl->minimum) * 1048 +
+                                             range / 2) / range + 1;
+                        u32 old;
+
+                        get_shutter(client, &old);
+                        dev_dbg(&client->dev, "Set shutter from %u to %u\n",
+                                old, shutter);
+                        if (set_shutter(client, shutter) < 0)
+                                return -EIO;
+                        mt9t031->exposure = ctrl->value;
+                        mt9t031->autoexposure = 0;
+                }
+                break;
+        case V4L2_CID_EXPOSURE_AUTO:
+                if (ctrl->value) {
+                        const u16 vblank = MT9T031_VERTICAL_BLANK;
+                        const u32 shutter_max = MT9T031_MAX_HEIGHT + vblank;
+                        unsigned int total_h = mt9t031->rect.height +
+                                mt9t031->y_skip_top + vblank;
+
+                        if (set_shutter(client, total_h) < 0)
+                                return -EIO;
+                        qctrl = &mt9t031_controls[MT9T031_CTRL_EXPOSURE];
+                        mt9t031->exposure = (shutter_max / 2 + (total_h - 1) *
+                                 (qctrl->maximum - qctrl->minimum)) /
+                                shutter_max + qctrl->minimum;
+                        mt9t031->autoexposure = 1;
+                } else
+                        mt9t031->autoexposure = 0;
+                break;
+        default:
+                return -EINVAL;
+        }
+        return 0;
+}
+
+/*
+ * Power Management:
+ * This function does nothing for now but must be present for pm to work
+ */
+static int mt9t031_runtime_suspend(struct device *dev)
+{
+        return 0;
+}
+
+/*
+ * Power Management:
+ * COLUMN_ADDRESS_MODE and ROW_ADDRESS_MODE are not rewritten if unchanged
+ * they are however changed at reset if the platform hook is present
+ * thus we rewrite them with the values stored by the driver
+ */
+static int mt9t031_runtime_resume(struct device *dev)
+{
+        struct video_device *vdev = to_video_device(dev);
+        struct soc_camera_device *icd = dev_get_drvdata(vdev->parent);
+        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
+        struct i2c_client *client = v4l2_get_subdevdata(sd);
+        struct mt9t031 *mt9t031 = to_mt9t031(client);
+
+        int ret;
+        u16 xbin, ybin;
+
+        xbin = min(mt9t031->xskip, (u16)3);
+        ybin = min(mt9t031->yskip, (u16)3);
+
+        ret = reg_write(client, MT9T031_COLUMN_ADDRESS_MODE,
+                ((xbin - 1) << 4) | (mt9t031->xskip - 1));
+        if (ret < 0)
+                return ret;
+
+        ret = reg_write(client, MT9T031_ROW_ADDRESS_MODE,
+                ((ybin - 1) << 4) | (mt9t031->yskip - 1));
+        if (ret < 0)
+                return ret;
+
+        return 0;
+}
+
+static struct dev_pm_ops mt9t031_dev_pm_ops = {
+        .runtime_suspend        = mt9t031_runtime_suspend,
+        .runtime_resume         = mt9t031_runtime_resume,
+};
+
+static struct device_type mt9t031_dev_type = {
+        .name   = "MT9T031",
+        .pm     = &mt9t031_dev_pm_ops,
+};
+
+/*
+ * Interface active, can use i2c. If it fails, it can indeed mean, that
+ * this wasn't our capture interface, so, we wait for the right one
+ */
+static int mt9t031_video_probe(struct i2c_client *client)
+{
+        struct mt9t031 *mt9t031 = to_mt9t031(client);
+        struct video_device *vdev = soc_camera_i2c_to_vdev(client);
+        s32 data;
+        int ret;
+
+        /* Enable the chip */
+        data = reg_write(client, MT9T031_CHIP_ENABLE, 1);
+        dev_dbg(&client->dev, "write: %d\n", data);
+
+        /* Read out the chip version register */
+        data = reg_read(client, MT9T031_CHIP_VERSION);
+
+        switch (data) {
+        case 0x1621:
+                mt9t031->model = V4L2_IDENT_MT9T031;
+                break;
+        default:
+                dev_err(&client->dev,
+                        "No MT9T031 chip detected, register read %x\n", data);
+                return -ENODEV;
+        }
+
+        dev_info(&client->dev, "Detected a MT9T031 chip ID %x\n", data);
+
+        ret = mt9t031_idle(client);
+        if (ret < 0)
+                dev_err(&client->dev, "Failed to initialise the camera\n");
+        else
+                vdev->dev.type = &mt9t031_dev_type;
+
+        /* mt9t031_idle() has reset the chip to default. */
+        mt9t031->exposure = 255;
+        mt9t031->gain = 64;
+
+        return ret;
+}
+
+static int mt9t031_g_skip_top_lines(struct v4l2_subdev *sd, u32 *lines)
+{
+        struct i2c_client *client = v4l2_get_subdevdata(sd);
+        struct mt9t031 *mt9t031 = to_mt9t031(client);
+
+        *lines = mt9t031->y_skip_top;
+
+        return 0;
+}
+
+static struct v4l2_subdev_core_ops mt9t031_subdev_core_ops = {
+        .g_ctrl         = mt9t031_g_ctrl,
+        .s_ctrl         = mt9t031_s_ctrl,
+        .g_chip_ident   = mt9t031_g_chip_ident,
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+        .g_register     = mt9t031_g_register,
+        .s_register     = mt9t031_s_register,
+#endif
+};
+
+static int mt9t031_enum_fmt(struct v4l2_subdev *sd, unsigned int index,
+                            enum v4l2_mbus_pixelcode *code)
+{
+        if (index)
+                return -EINVAL;
+
+        *code = V4L2_MBUS_FMT_SBGGR10_1X10;
+        return 0;
+}
+
+static struct v4l2_subdev_video_ops mt9t031_subdev_video_ops = {
+        .s_stream       = mt9t031_s_stream,
+        .s_mbus_fmt     = mt9t031_s_fmt,
+        .g_mbus_fmt     = mt9t031_g_fmt,
+        .try_mbus_fmt   = mt9t031_try_fmt,
+        .s_crop         = mt9t031_s_crop,
+        .g_crop         = mt9t031_g_crop,
+        .cropcap        = mt9t031_cropcap,
+        .enum_mbus_fmt  = mt9t031_enum_fmt,
+};
+
+static struct v4l2_subdev_sensor_ops mt9t031_subdev_sensor_ops = {
+        .g_skip_top_lines       = mt9t031_g_skip_top_lines,
+};
+
+static struct v4l2_subdev_ops mt9t031_subdev_ops = {
+        .core   = &mt9t031_subdev_core_ops,
+        .video  = &mt9t031_subdev_video_ops,
+        .sensor = &mt9t031_subdev_sensor_ops,
+};
+
+static int mt9t031_probe(struct i2c_client *client,
+                         const struct i2c_device_id *did)
+{
+        struct mt9t031 *mt9t031;
+        struct soc_camera_device *icd = client->dev.platform_data;
+        struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
+        int ret;
+
+        if (icd) {
+                struct soc_camera_link *icl = to_soc_camera_link(icd);
+                if (!icl) {
+                        dev_err(&client->dev, "MT9T031 driver needs platform data\n");
+                        return -EINVAL;
+                }
+
+                icd->ops = &mt9t031_ops;
+        }
+
+        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) {
+                dev_warn(&adapter->dev,
+                         "I2C-Adapter doesn't support I2C_FUNC_SMBUS_WORD\n");
+                return -EIO;
+        }
+
+        mt9t031 = kzalloc(sizeof(struct mt9t031), GFP_KERNEL);
+        if (!mt9t031)
+                return -ENOMEM;
+
+        v4l2_i2c_subdev_init(&mt9t031->subdev, client, &mt9t031_subdev_ops);
+
+        mt9t031->y_skip_top     = 0;
+        mt9t031->rect.left      = MT9T031_COLUMN_SKIP;
+        mt9t031->rect.top       = MT9T031_ROW_SKIP;
+        mt9t031->rect.width     = MT9T031_MAX_WIDTH;
+        mt9t031->rect.height    = MT9T031_MAX_HEIGHT;
+
+        /*
+         * Simulated autoexposure. If enabled, we calculate shutter width
+         * ourselves in the driver based on vertical blanking and frame width
+         */
+        mt9t031->autoexposure = 1;
+
+        mt9t031->xskip = 1;
+        mt9t031->yskip = 1;
+
+        mt9t031_idle(client);
+
+        ret = mt9t031_video_probe(client);
+
+        mt9t031_disable(client);
+
+        if (ret) {
+                if (icd)
+                        icd->ops = NULL;
+                kfree(mt9t031);
+        }
+
+        return ret;
+}
+
+static int mt9t031_remove(struct i2c_client *client)
+{
+        struct mt9t031 *mt9t031 = to_mt9t031(client);
+        struct soc_camera_device *icd = client->dev.platform_data;
+
+        if (icd)
+                icd->ops = NULL;
+        kfree(mt9t031);
+
+        return 0;
+}
+
+static const struct i2c_device_id mt9t031_id[] = {
+        { "mt9t031", 0 },
+        { }
+};
+MODULE_DEVICE_TABLE(i2c, mt9t031_id);
+
+static struct i2c_driver mt9t031_i2c_driver = {
+        .driver = {
+                .name = "mt9t031",
+        },
+        .probe          = mt9t031_probe,
+        .remove         = mt9t031_remove,
+        .id_table       = mt9t031_id,
+};
+
+static int __init mt9t031_mod_init(void)
+{
+        return i2c_add_driver(&mt9t031_i2c_driver);
+}
+
+static void __exit mt9t031_mod_exit(void)
+{
+        i2c_del_driver(&mt9t031_i2c_driver);
+}
+
+module_init(mt9t031_mod_init);
+module_exit(mt9t031_mod_exit);
+
+MODULE_DESCRIPTION("Micron MT9T031 Camera driver");
+MODULE_AUTHOR("Guennadi Liakhovetski <lg@denx.de>");
+MODULE_LICENSE("GPL v2");