V4L/DVB (10099): soc-camera: add support for MT9T031 CMOS camera sensor from Micron

This camera is rather similar to MT9M001, but also has a couple of
enhanced features, like pixel binning.

 create mode 100644 drivers/media/video/mt9t031.c

Signed-off-by: Guennadi Liakhovetski <lg@denx.de>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

3 files changed, 743 insertions, 0 deletions

diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
index 9785eeb1ed44..19cf3b8f67c4 100644
--- a/drivers/media/video/Kconfig
+++ b/drivers/media/video/Kconfig
@@ -741,6 +741,12 @@ config SOC_CAMERA_MT9M111
         help
           This driver supports MT9M111 and MT9M112 cameras from Micron
 
+config SOC_CAMERA_MT9T031
+        tristate "mt9t031 support"
+        depends on SOC_CAMERA && I2C
+        help
+          This driver supports MT9T031 cameras from Micron.
+
 config SOC_CAMERA_MT9V022
         tristate "mt9v022 support"
         depends on SOC_CAMERA && I2C
diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
index 40c69afcde7a..1611c33b1aee 100644
--- a/drivers/media/video/Makefile
+++ b/drivers/media/video/Makefile
@@ -137,6 +137,7 @@ obj-$(CONFIG_VIDEO_OMAP2)		+= omap2cam.o
 obj-$(CONFIG_SOC_CAMERA)        += soc_camera.o
 obj-$(CONFIG_SOC_CAMERA_MT9M001)        += mt9m001.o
 obj-$(CONFIG_SOC_CAMERA_MT9M111)        += mt9m111.o
+obj-$(CONFIG_SOC_CAMERA_MT9T031)        += mt9t031.o
 obj-$(CONFIG_SOC_CAMERA_MT9V022)        += mt9v022.o
 obj-$(CONFIG_SOC_CAMERA_OV772X)         += ov772x.o
 obj-$(CONFIG_SOC_CAMERA_PLATFORM)       += soc_camera_platform.o
diff --git a/drivers/media/video/mt9t031.c b/drivers/media/video/mt9t031.c
new file mode 100644
index 000000000000..1a9d53966d06
--- /dev/null
+++ b/drivers/media/video/mt9t031.c
@@ -0,0 +1,736 @@
+/*
+ * 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/videodev2.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/log2.h>
+
+#include <media/v4l2-common.h>
+#include <media/v4l2-chip-ident.h>
+#include <media/soc_camera.h>
+
+/* mt9t031 i2c address 0x5d
+ * The platform has to define i2c_board_info
+ * and call i2c_register_board_info() */
+
+/* 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               2
+#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)
+
+static const struct soc_camera_data_format mt9t031_colour_formats[] = {
+        {
+                .name           = "Bayer (sRGB) 10 bit",
+                .depth          = 10,
+                .fourcc         = V4L2_PIX_FMT_SGRBG10,
+                .colorspace     = V4L2_COLORSPACE_SRGB,
+        }
+};
+
+struct mt9t031 {
+        struct i2c_client *client;
+        struct soc_camera_device icd;
+        int model;      /* V4L2_IDENT_MT9T031* codes from v4l2-chip-ident.h */
+        unsigned char autoexposure;
+        u16 xskip;
+        u16 yskip;
+};
+
+static int reg_read(struct soc_camera_device *icd, const u8 reg)
+{
+        struct mt9t031 *mt9t031 = container_of(icd, struct mt9t031, icd);
+        struct i2c_client *client = mt9t031->client;
+        s32 data = i2c_smbus_read_word_data(client, reg);
+        return data < 0 ? data : swab16(data);
+}
+
+static int reg_write(struct soc_camera_device *icd, const u8 reg,
+                     const u16 data)
+{
+        struct mt9t031 *mt9t031 = container_of(icd, struct mt9t031, icd);
+        return i2c_smbus_write_word_data(mt9t031->client, reg, swab16(data));
+}
+
+static int reg_set(struct soc_camera_device *icd, const u8 reg,
+                   const u16 data)
+{
+        int ret;
+
+        ret = reg_read(icd, reg);
+        if (ret < 0)
+                return ret;
+        return reg_write(icd, reg, ret | data);
+}
+
+static int reg_clear(struct soc_camera_device *icd, const u8 reg,
+                     const u16 data)
+{
+        int ret;
+
+        ret = reg_read(icd, reg);
+        if (ret < 0)
+                return ret;
+        return reg_write(icd, reg, ret & ~data);
+}
+
+static int set_shutter(struct soc_camera_device *icd, const u32 data)
+{
+        int ret;
+
+        ret = reg_write(icd, MT9T031_SHUTTER_WIDTH_UPPER, data >> 16);
+
+        if (ret >= 0)
+                ret = reg_write(icd, MT9T031_SHUTTER_WIDTH, data & 0xffff);
+
+        return ret;
+}
+
+static int get_shutter(struct soc_camera_device *icd, u32 *data)
+{
+        int ret;
+
+        ret = reg_read(icd, MT9T031_SHUTTER_WIDTH_UPPER);
+        *data = ret << 16;
+
+        if (ret >= 0)
+                ret = reg_read(icd, MT9T031_SHUTTER_WIDTH);
+        *data |= ret & 0xffff;
+
+        return ret < 0 ? ret : 0;
+}
+
+static int mt9t031_init(struct soc_camera_device *icd)
+{
+        int ret;
+
+        /* Disable chip output, synchronous option update */
+        dev_dbg(icd->vdev->parent, "%s\n", __func__);
+
+        ret = reg_write(icd, MT9T031_RESET, 1);
+        if (ret >= 0)
+                ret = reg_write(icd, MT9T031_RESET, 0);
+        if (ret >= 0)
+                ret = reg_clear(icd, MT9T031_OUTPUT_CONTROL, 3);
+
+        return ret >= 0 ? 0 : -EIO;
+}
+
+static int mt9t031_release(struct soc_camera_device *icd)
+{
+        /* Disable the chip */
+        reg_clear(icd, MT9T031_OUTPUT_CONTROL, 3);
+        return 0;
+}
+
+static int mt9t031_start_capture(struct soc_camera_device *icd)
+{
+        /* Switch to master "normal" mode */
+        if (reg_set(icd, MT9T031_OUTPUT_CONTROL, 3) < 0)
+                return -EIO;
+        return 0;
+}
+
+static int mt9t031_stop_capture(struct soc_camera_device *icd)
+{
+        /* Stop sensor readout */
+        if (reg_clear(icd, MT9T031_OUTPUT_CONTROL, 3) < 0)
+                return -EIO;
+        return 0;
+}
+
+static int mt9t031_set_bus_param(struct soc_camera_device *icd,
+                                 unsigned long flags)
+{
+        /* The caller should have queried our parameters, check anyway */
+        if (flags & ~MT9T031_BUS_PARAM)
+                return -EINVAL;
+
+        if (flags & SOCAM_PCLK_SAMPLE_FALLING)
+                reg_set(icd, MT9T031_PIXEL_CLOCK_CONTROL, 0x8000);
+        else
+                reg_clear(icd, MT9T031_PIXEL_CLOCK_CONTROL, 0x8000);
+
+        return 0;
+}
+
+static unsigned long mt9t031_query_bus_param(struct soc_camera_device *icd)
+{
+        struct mt9t031 *mt9t031 = container_of(icd, struct mt9t031, icd);
+        struct soc_camera_link *icl = mt9t031->client->dev.platform_data;
+
+        return soc_camera_apply_sensor_flags(icl, MT9T031_BUS_PARAM);
+}
+
+static int mt9t031_set_fmt(struct soc_camera_device *icd,
+                           __u32 pixfmt, struct v4l2_rect *rect)
+{
+        struct mt9t031 *mt9t031 = container_of(icd, struct mt9t031, icd);
+        int ret;
+        const u16 hblank = MT9T031_HORIZONTAL_BLANK,
+                vblank = MT9T031_VERTICAL_BLANK;
+        u16 xbin, xskip = mt9t031->xskip, ybin, yskip = mt9t031->yskip,
+                width = rect->width * xskip, height = rect->height * yskip;
+
+        if (pixfmt) {
+                /* S_FMT - use binning and skipping for scaling, recalculate */
+                /* Is this more optimal than just a division? */
+                for (xskip = 8; xskip > 1; xskip--)
+                        if (rect->width * xskip <= icd->width_max)
+                                break;
+
+                for (yskip = 8; yskip > 1; yskip--)
+                        if (rect->height * yskip <= icd->height_max)
+                                break;
+
+                width = rect->width * xskip;
+                height = rect->height * yskip;
+
+                dev_dbg(&icd->dev, "xskip %u, width %u, yskip %u, height %u\n",
+                        xskip, width, yskip, height);
+        }
+
+        xbin = min(xskip, (u16)3);
+        ybin = min(yskip, (u16)3);
+
+        /* Make sure we don't exceed frame limits */
+        if (rect->left + width > icd->width_max)
+                rect->left = (icd->width_max - width) / 2;
+
+        if (rect->top + height > icd->height_max)
+                rect->top = (icd->height_max - height) / 2;
+
+        /* Could just do roundup(rect->left, [xy]bin); but this is cheaper */
+        switch (xbin) {
+        case 2:
+                rect->left = (rect->left + 1) & ~1;
+                break;
+        case 3:
+                rect->left = roundup(rect->left, 3);
+        }
+
+        switch (ybin) {
+        case 2:
+                rect->top = (rect->top + 1) & ~1;
+                break;
+        case 3:
+                rect->top = roundup(rect->top, 3);
+        }
+
+        /* Blanking and start values - default... */
+        ret = reg_write(icd, MT9T031_HORIZONTAL_BLANKING, hblank);
+        if (ret >= 0)
+                ret = reg_write(icd, MT9T031_VERTICAL_BLANKING, vblank);
+
+        if (pixfmt) {
+                /* Binning, skipping */
+                if (ret >= 0)
+                        ret = reg_write(icd, MT9T031_COLUMN_ADDRESS_MODE,
+                                        ((xbin - 1) << 4) | (xskip - 1));
+                if (ret >= 0)
+                        ret = reg_write(icd, MT9T031_ROW_ADDRESS_MODE,
+                                        ((ybin - 1) << 4) | (yskip - 1));
+        }
+        dev_dbg(&icd->dev, "new 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(icd, MT9T031_COLUMN_START, rect->left);
+        if (ret >= 0)
+                ret = reg_write(icd, MT9T031_ROW_START, rect->top);
+        if (ret >= 0)
+                ret = reg_write(icd, MT9T031_WINDOW_WIDTH, width - 1);
+        if (ret >= 0)
+                ret = reg_write(icd, MT9T031_WINDOW_HEIGHT,
+                                height + icd->y_skip_top - 1);
+        if (ret >= 0 && mt9t031->autoexposure) {
+                ret = set_shutter(icd, height + icd->y_skip_top + vblank);
+                if (ret >= 0) {
+                        const u32 shutter_max = MT9T031_MAX_HEIGHT + vblank;
+                        const struct v4l2_queryctrl *qctrl =
+                                soc_camera_find_qctrl(icd->ops,
+                                                      V4L2_CID_EXPOSURE);
+                        icd->exposure = (shutter_max / 2 + (height +
+                                         icd->y_skip_top + vblank - 1) *
+                                         (qctrl->maximum - qctrl->minimum)) /
+                                shutter_max + qctrl->minimum;
+                }
+        }
+
+        if (!ret && pixfmt) {
+                mt9t031->xskip = xskip;
+                mt9t031->yskip = yskip;
+        }
+
+        return ret < 0 ? ret : 0;
+}
+
+static int mt9t031_try_fmt(struct soc_camera_device *icd,
+                           struct v4l2_format *f)
+{
+        struct v4l2_pix_format *pix = &f->fmt.pix;
+
+        if (pix->height < icd->height_min)
+                pix->height = icd->height_min;
+        if (pix->height > icd->height_max)
+                pix->height = icd->height_max;
+        if (pix->width < icd->width_min)
+                pix->width = icd->width_min;
+        if (pix->width > icd->width_max)
+                pix->width = icd->width_max;
+
+        pix->width &= ~0x01; /* has to be even */
+        pix->height &= ~0x01; /* has to be even */
+
+        return 0;
+}
+
+static int mt9t031_get_chip_id(struct soc_camera_device *icd,
+                               struct v4l2_chip_ident *id)
+{
+        struct mt9t031 *mt9t031 = container_of(icd, struct mt9t031, icd);
+
+        if (id->match_type != V4L2_CHIP_MATCH_I2C_ADDR)
+                return -EINVAL;
+
+        if (id->match_chip != mt9t031->client->addr)
+                return -ENODEV;
+
+        id->ident       = mt9t031->model;
+        id->revision    = 0;
+
+        return 0;
+}
+
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+static int mt9t031_get_register(struct soc_camera_device *icd,
+                                struct v4l2_register *reg)
+{
+        struct mt9t031 *mt9t031 = container_of(icd, struct mt9t031, icd);
+
+        if (reg->match_type != V4L2_CHIP_MATCH_I2C_ADDR || reg->reg > 0xff)
+                return -EINVAL;
+
+        if (reg->match_chip != mt9t031->client->addr)
+                return -ENODEV;
+
+        reg->val = reg_read(icd, reg->reg);
+
+        if (reg->val > 0xffff)
+                return -EIO;
+
+        return 0;
+}
+
+static int mt9t031_set_register(struct soc_camera_device *icd,
+                                struct v4l2_register *reg)
+{
+        struct mt9t031 *mt9t031 = container_of(icd, struct mt9t031, icd);
+
+        if (reg->match_type != V4L2_CHIP_MATCH_I2C_ADDR || reg->reg > 0xff)
+                return -EINVAL;
+
+        if (reg->match_chip != mt9t031->client->addr)
+                return -ENODEV;
+
+        if (reg_write(icd, reg->reg, reg->val) < 0)
+                return -EIO;
+
+        return 0;
+}
+#endif
+
+static const struct v4l2_queryctrl mt9t031_controls[] = {
+        {
+                .id             = V4L2_CID_VFLIP,
+                .type           = V4L2_CTRL_TYPE_BOOLEAN,
+                .name           = "Flip Vertically",
+                .minimum        = 0,
+                .maximum        = 1,
+                .step           = 1,
+                .default_value  = 0,
+        }, {
+                .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,
+        }, {
+                .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,
+        }, {
+                .id             = V4L2_CID_EXPOSURE_AUTO,
+                .type           = V4L2_CTRL_TYPE_BOOLEAN,
+                .name           = "Automatic Exposure",
+                .minimum        = 0,
+                .maximum        = 1,
+                .step           = 1,
+                .default_value  = 1,
+        }
+};
+
+static int mt9t031_video_probe(struct soc_camera_device *);
+static void mt9t031_video_remove(struct soc_camera_device *);
+static int mt9t031_get_control(struct soc_camera_device *, struct v4l2_control *);
+static int mt9t031_set_control(struct soc_camera_device *, struct v4l2_control *);
+
+static struct soc_camera_ops mt9t031_ops = {
+        .owner                  = THIS_MODULE,
+        .probe                  = mt9t031_video_probe,
+        .remove                 = mt9t031_video_remove,
+        .init                   = mt9t031_init,
+        .release                = mt9t031_release,
+        .start_capture          = mt9t031_start_capture,
+        .stop_capture           = mt9t031_stop_capture,
+        .set_fmt                = mt9t031_set_fmt,
+        .try_fmt                = mt9t031_try_fmt,
+        .set_bus_param          = mt9t031_set_bus_param,
+        .query_bus_param        = mt9t031_query_bus_param,
+        .controls               = mt9t031_controls,
+        .num_controls           = ARRAY_SIZE(mt9t031_controls),
+        .get_control            = mt9t031_get_control,
+        .set_control            = mt9t031_set_control,
+        .get_chip_id            = mt9t031_get_chip_id,
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+        .get_register           = mt9t031_get_register,
+        .set_register           = mt9t031_set_register,
+#endif
+};
+
+static int mt9t031_get_control(struct soc_camera_device *icd, struct v4l2_control *ctrl)
+{
+        struct mt9t031 *mt9t031 = container_of(icd, struct mt9t031, icd);
+        int data;
+
+        switch (ctrl->id) {
+        case V4L2_CID_VFLIP:
+                data = reg_read(icd, MT9T031_READ_MODE_2);
+                if (data < 0)
+                        return -EIO;
+                ctrl->value = !!(data & 0x8000);
+                break;
+        case V4L2_CID_HFLIP:
+                data = reg_read(icd, MT9T031_READ_MODE_2);
+                if (data < 0)
+                        return -EIO;
+                ctrl->value = !!(data & 0x4000);
+                break;
+        case V4L2_CID_EXPOSURE_AUTO:
+                ctrl->value = mt9t031->autoexposure;
+                break;
+        }
+        return 0;
+}
+
+static int mt9t031_set_control(struct soc_camera_device *icd, struct v4l2_control *ctrl)
+{
+        struct mt9t031 *mt9t031 = container_of(icd, struct mt9t031, icd);
+        const struct v4l2_queryctrl *qctrl;
+        int data;
+
+        qctrl = soc_camera_find_qctrl(&mt9t031_ops, ctrl->id);
+
+        if (!qctrl)
+                return -EINVAL;
+
+        switch (ctrl->id) {
+        case V4L2_CID_VFLIP:
+                if (ctrl->value)
+                        data = reg_set(icd, MT9T031_READ_MODE_2, 0x8000);
+                else
+                        data = reg_clear(icd, MT9T031_READ_MODE_2, 0x8000);
+                if (data < 0)
+                        return -EIO;
+                break;
+        case V4L2_CID_HFLIP:
+                if (ctrl->value)
+                        data = reg_set(icd, MT9T031_READ_MODE_2, 0x4000);
+                else
+                        data = reg_clear(icd, MT9T031_READ_MODE_2, 0x4000);
+                if (data < 0)
+                        return -EIO;
+                break;
+        case V4L2_CID_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(&icd->dev, "Setting gain %d\n", data);
+                        data = reg_write(icd, MT9T031_GLOBAL_GAIN, data);
+                        if (data < 0)
+                                return -EIO;
+                } else {
+                        /* Pack it into 1.125..15 variable step, register values 9..67 */
+                        /* We assume qctrl->maximum - qctrl->default_value - 1 > 0 */
+                        unsigned long range = qctrl->maximum - qctrl->default_value - 1;
+                        unsigned long gain = ((ctrl->value - qctrl->default_value - 1) *
+                                               111 + range / 2) / range + 9;
+
+                        if (gain <= 32)
+                                data = gain;
+                        else if (gain <= 64)
+                                data = ((gain - 32) * 16 + 16) / 32 + 80;
+                        else
+                                data = ((gain - 64) * 7 + 28) / 56 + 96;
+
+                        dev_dbg(&icd->dev, "Setting gain from %d to %d\n",
+                                 reg_read(icd, MT9T031_GLOBAL_GAIN), data);
+                        data = reg_write(icd, MT9T031_GLOBAL_GAIN, data);
+                        if (data < 0)
+                                return -EIO;
+                }
+
+                /* Success */
+                icd->gain = ctrl->value;
+                break;
+        case V4L2_CID_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(icd, &old);
+                        dev_dbg(&icd->dev, "Setting shutter width from %u to %u\n",
+                                old, shutter);
+                        if (set_shutter(icd, shutter) < 0)
+                                return -EIO;
+                        icd->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;
+                        if (set_shutter(icd, icd->height +
+                                        icd->y_skip_top + vblank) < 0)
+                                return -EIO;
+                        qctrl = soc_camera_find_qctrl(icd->ops, V4L2_CID_EXPOSURE);
+                        icd->exposure = (shutter_max / 2 + (icd->height +
+                                         icd->y_skip_top + vblank - 1) *
+                                         (qctrl->maximum - qctrl->minimum)) /
+                                shutter_max + qctrl->minimum;
+                        mt9t031->autoexposure = 1;
+                } else
+                        mt9t031->autoexposure = 0;
+                break;
+        }
+        return 0;
+}
+
+/* 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 soc_camera_device *icd)
+{
+        struct mt9t031 *mt9t031 = container_of(icd, struct mt9t031, icd);
+        s32 data;
+        int ret;
+
+        /* We must have a parent by now. And it cannot be a wrong one.
+         * So this entire test is completely redundant. */
+        if (!icd->dev.parent ||
+            to_soc_camera_host(icd->dev.parent)->nr != icd->iface)
+                return -ENODEV;
+
+        /* Enable the chip */
+        data = reg_write(icd, MT9T031_CHIP_ENABLE, 1);
+        dev_dbg(&icd->dev, "write: %d\n", data);
+
+        /* Read out the chip version register */
+        data = reg_read(icd, MT9T031_CHIP_VERSION);
+
+        switch (data) {
+        case 0x1621:
+                mt9t031->model = V4L2_IDENT_MT9T031;
+                icd->formats = mt9t031_colour_formats;
+                icd->num_formats = ARRAY_SIZE(mt9t031_colour_formats);
+                break;
+        default:
+                ret = -ENODEV;
+                dev_err(&icd->dev,
+                        "No MT9T031 chip detected, register read %x\n", data);
+                goto ei2c;
+        }
+
+        dev_info(&icd->dev, "Detected a MT9T031 chip ID %x\n", data);
+
+        /* Now that we know the model, we can start video */
+        ret = soc_camera_video_start(icd);
+        if (ret)
+                goto evstart;
+
+        return 0;
+
+evstart:
+ei2c:
+        return ret;
+}
+
+static void mt9t031_video_remove(struct soc_camera_device *icd)
+{
+        struct mt9t031 *mt9t031 = container_of(icd, struct mt9t031, icd);
+
+        dev_dbg(&icd->dev, "Video %x removed: %p, %p\n", mt9t031->client->addr,
+                icd->dev.parent, icd->vdev);
+        soc_camera_video_stop(icd);
+}
+
+static int mt9t031_probe(struct i2c_client *client,
+                         const struct i2c_device_id *did)
+{
+        struct mt9t031 *mt9t031;
+        struct soc_camera_device *icd;
+        struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
+        struct soc_camera_link *icl = client->dev.platform_data;
+        int ret;
+
+        if (!icl) {
+                dev_err(&client->dev, "MT9T031 driver needs platform data\n");
+                return -EINVAL;
+        }
+
+        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;
+
+        mt9t031->client = client;
+        i2c_set_clientdata(client, mt9t031);
+
+        /* Second stage probe - when a capture adapter is there */
+        icd = &mt9t031->icd;
+        icd->ops        = &mt9t031_ops;
+        icd->control    = &client->dev;
+        icd->x_min      = MT9T031_COLUMN_SKIP;
+        icd->y_min      = MT9T031_ROW_SKIP;
+        icd->x_current  = icd->x_min;
+        icd->y_current  = icd->y_min;
+        icd->width_min  = MT9T031_MIN_WIDTH;
+        icd->width_max  = MT9T031_MAX_WIDTH;
+        icd->height_min = MT9T031_MIN_HEIGHT;
+        icd->height_max = MT9T031_MAX_HEIGHT;
+        icd->y_skip_top = 0;
+        icd->iface      = icl->bus_id;
+        /* 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;
+
+        ret = soc_camera_device_register(icd);
+        if (ret)
+                goto eisdr;
+
+        return 0;
+
+eisdr:
+        i2c_set_clientdata(client, NULL);
+        kfree(mt9t031);
+        return ret;
+}
+
+static int mt9t031_remove(struct i2c_client *client)
+{
+        struct mt9t031 *mt9t031 = i2c_get_clientdata(client);
+
+        soc_camera_device_unregister(&mt9t031->icd);
+        i2c_set_clientdata(client, 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");