V4L/DVB (10673): mt9t031: fix gain and hflip controls, register update, and scaling

Multiple fixes:
1. allow register update by setting the Output Control register to 2 and not 3
2. fix scaling factor calculations
3. recover lost HFLIP control
4. fix Global Gain calculation

Signed-off-by: Guennadi Liakhovetski <lg@denx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/video/mt9t031.c b/drivers/media/video/mt9t031.c
index 349d8e3..acc1fa9 100644 (file)
--- a/drivers/media/video/mt9t031.c
+++ b/drivers/media/video/mt9t031.c
@@ -150,7 +150,7 @@ static int mt9t031_init(struct soc_camera_device *icd)
        if (ret >= 0)
                ret = reg_write(icd, MT9T031_RESET, 0);
        if (ret >= 0)
-               ret = reg_clear(icd, MT9T031_OUTPUT_CONTROL, 3);
+               ret = reg_clear(icd, MT9T031_OUTPUT_CONTROL, 2);
 
        return ret >= 0 ? 0 : -EIO;
 }
@@ -158,14 +158,14 @@ static int mt9t031_init(struct soc_camera_device *icd)
 static int mt9t031_release(struct soc_camera_device *icd)
 {
        /* Disable the chip */
-       reg_clear(icd, MT9T031_OUTPUT_CONTROL, 3);
+       reg_clear(icd, MT9T031_OUTPUT_CONTROL, 2);
        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)
+       if (reg_set(icd, MT9T031_OUTPUT_CONTROL, 2) < 0)
                return -EIO;
        return 0;
 }
@@ -173,7 +173,7 @@ static int mt9t031_start_capture(struct soc_camera_device *icd)
 static int mt9t031_stop_capture(struct soc_camera_device *icd)
 {
        /* Stop sensor readout */
-       if (reg_clear(icd, MT9T031_OUTPUT_CONTROL, 3) < 0)
+       if (reg_clear(icd, MT9T031_OUTPUT_CONTROL, 2) < 0)
                return -EIO;
        return 0;
 }
@@ -201,6 +201,18 @@ static unsigned long mt9t031_query_bus_param(struct soc_camera_device *icd)
        return soc_camera_apply_sensor_flags(icl, MT9T031_BUS_PARAM);
 }
 
+/* Round up minima and round down maxima */
+static void recalculate_limits(struct soc_camera_device *icd,
+                              u16 xskip, u16 yskip)
+{
+       icd->x_min = (MT9T031_COLUMN_SKIP + xskip - 1) / xskip;
+       icd->y_min = (MT9T031_ROW_SKIP + yskip - 1) / yskip;
+       icd->width_min = (MT9T031_MIN_WIDTH + xskip - 1) / xskip;
+       icd->height_min = (MT9T031_MIN_HEIGHT + yskip - 1) / yskip;
+       icd->width_max = MT9T031_MAX_WIDTH / xskip;
+       icd->height_max = MT9T031_MAX_HEIGHT / yskip;
+}
+
 static int mt9t031_set_fmt(struct soc_camera_device *icd,
                           __u32 pixfmt, struct v4l2_rect *rect)
 {
@@ -208,54 +220,70 @@ static int mt9t031_set_fmt(struct soc_camera_device *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;
+       u16 xbin, xskip, ybin, yskip, width, height, left, top;
 
        if (pixfmt) {
-               /* S_FMT - use binning and skipping for scaling, recalculate */
+               /*
+                * try_fmt has put rectangle within limits.
+                * S_FMT - use binning and skipping for scaling, recalculate
+                * limits, used for cropping
+                */
                /* Is this more optimal than just a division? */
                for (xskip = 8; xskip > 1; xskip--)
-                       if (rect->width * xskip <= icd->width_max)
+                       if (rect->width * xskip <= MT9T031_MAX_WIDTH)
                                break;
 
                for (yskip = 8; yskip > 1; yskip--)
-                       if (rect->height * yskip <= icd->height_max)
+                       if (rect->height * yskip <= MT9T031_MAX_HEIGHT)
                                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);
+               recalculate_limits(icd, xskip, yskip);
+       } else {
+               /* CROP - no change in scaling, or in limits */
+               xskip = mt9t031->xskip;
+               yskip = mt9t031->yskip;
        }
 
+       /* Make sure we don't exceed sensor limits */
+       if (rect->left + rect->width > icd->width_max)
+               rect->left = (icd->width_max - rect->width) / 2 + icd->x_min;
+
+       if (rect->top + rect->height > icd->height_max)
+               rect->top = (icd->height_max - rect->height) / 2 + icd->y_min;
+
+       width = rect->width * xskip;
+       height = rect->height * yskip;
+       left = rect->left * xskip;
+       top = rect->top * yskip;
+
        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;
+       dev_dbg(&icd->dev, "xskip %u, width %u/%u, yskip %u, height %u/%u\n",
+               xskip, width, rect->width, yskip, height, rect->height);
 
-       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 */
+       /* Could just do roundup(rect->left, [xy]bin * 2); but this is cheaper */
        switch (xbin) {
        case 2:
-               rect->left = (rect->left + 1) & ~1;
+               left = (left + 3) & ~3;
                break;
        case 3:
-               rect->left = roundup(rect->left, 3);
+               left = roundup(left, 6);
        }
 
        switch (ybin) {
        case 2:
-               rect->top = (rect->top + 1) & ~1;
+               top = (top + 3) & ~3;
                break;
        case 3:
-               rect->top = roundup(rect->top, 3);
+               top = roundup(top, 6);
        }
 
+       /* Disable register update, reconfigure atomically */
+       ret = reg_set(icd, MT9T031_OUTPUT_CONTROL, 1);
+       if (ret < 0)
+               return ret;
+
        /* Blanking and start values - default... */
        ret = reg_write(icd, MT9T031_HORIZONTAL_BLANKING, hblank);
        if (ret >= 0)
@@ -270,14 +298,14 @@ static int mt9t031_set_fmt(struct soc_camera_device *icd,
                        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);
+       dev_dbg(&icd->dev, "new physical left %u, top %u\n", left, 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);
+               ret = reg_write(icd, MT9T031_COLUMN_START, left);
        if (ret >= 0)
-               ret = reg_write(icd, MT9T031_ROW_START, rect->top);
+               ret = reg_write(icd, MT9T031_ROW_START, top);
        if (ret >= 0)
                ret = reg_write(icd, MT9T031_WINDOW_WIDTH, width - 1);
        if (ret >= 0)
@@ -302,6 +330,9 @@ static int mt9t031_set_fmt(struct soc_camera_device *icd,
                mt9t031->yskip = yskip;
        }
 
+       /* Re-enable register update, commit all changes */
+       reg_clear(icd, MT9T031_OUTPUT_CONTROL, 1);
+
        return ret < 0 ? ret : 0;
 }
 
@@ -310,14 +341,14 @@ static int mt9t031_try_fmt(struct soc_camera_device *icd,
 {
        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;
+       if (pix->height < MT9T031_MIN_HEIGHT)
+               pix->height = MT9T031_MIN_HEIGHT;
+       if (pix->height > MT9T031_MAX_HEIGHT)
+               pix->height = MT9T031_MAX_HEIGHT;
+       if (pix->width < MT9T031_MIN_WIDTH)
+               pix->width = MT9T031_MIN_WIDTH;
+       if (pix->width > MT9T031_MAX_WIDTH)
+               pix->width = MT9T031_MAX_WIDTH;
 
        pix->width &= ~0x01; /* has to be even */
        pix->height &= ~0x01; /* has to be even */
@@ -390,6 +421,14 @@ static const struct v4l2_queryctrl mt9t031_controls[] = {
                .step           = 1,
                .default_value  = 0,
        }, {
+               .id             = V4L2_CID_HFLIP,
+               .type           = V4L2_CTRL_TYPE_BOOLEAN,
+               .name           = "Flip Horizontally",
+               .minimum        = 0,
+               .maximum        = 1,
+               .step           = 1,
+               .default_value  = 0,
+       }, {
                .id             = V4L2_CID_GAIN,
                .type           = V4L2_CTRL_TYPE_INTEGER,
                .name           = "Gain",
@@ -513,21 +552,23 @@ static int mt9t031_set_control(struct soc_camera_device *icd, struct v4l2_contro
                        if (data < 0)
                                return -EIO;
                } else {
-                       /* Pack it into 1.125..15 variable step, register values 9..67 */
+                       /* 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) *
-                                              111 + range / 2) / range + 9;
+                                              1015 + range / 2) / range + 9;
 
-                       if (gain <= 32)
+                       if (gain <= 32)         /* calculated gain 9..32 -> 9..32 */
                                data = gain;
-                       else if (gain <= 64)
+                       else if (gain <= 64)    /* calculated gain 33..64 -> 0x51..0x60 */
                                data = ((gain - 32) * 16 + 16) / 32 + 80;
                        else
-                               data = ((gain - 64) * 7 + 28) / 56 + 96;
+                               /* calculated gain 65..1024 -> (1..120) << 8 + 0x60 */
+                               data = (((gain - 64 + 7) * 32) & 0xff00) | 0x60;
 
-                       dev_dbg(&icd->dev, "Setting gain from %d to %d\n",
-                                reg_read(icd, MT9T031_GLOBAL_GAIN), data);
+                       dev_dbg(&icd->dev, "Setting gain from 0x%x to 0x%x\n",
+                               reg_read(icd, MT9T031_GLOBAL_GAIN), data);
                        data = reg_write(icd, MT9T031_GLOBAL_GAIN, data);
                        if (data < 0)
                                return -EIO;