media: i2c: imx290: Convert V4L2_CID_VBLANK to read/write

The driver exposed V4L2_CID_VBLANK as a read only control to allow
for exposure calculations and determination of the frame rate.

Convert to a read/write control so that the frame rate can be
controlled.
V4L2_CID_VBLANK also sets the limits for the exposure control,
therefore exposure ranges have to be updated when vblank changes
(either via s_ctrl, or via changing mode).

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

diff --git a/drivers/media/i2c/imx290.c b/drivers/media/i2c/imx290.c
index ca5fdc5..09d2687 100644 (file)
--- a/drivers/media/i2c/imx290.c
+++ b/drivers/media/i2c/imx290.c
@@ -49,6 +49,7 @@
 #define IMX290_BLKLEVEL                                        IMX290_REG_16BIT(0x300a)
 #define IMX290_GAIN                                    IMX290_REG_8BIT(0x3014)
 #define IMX290_VMAX                                    IMX290_REG_24BIT(0x3018)
+#define IMX290_VMAX_MAX                                        0x3ffff
 #define IMX290_HMAX                                    IMX290_REG_16BIT(0x301c)
 #define IMX290_HMAX_MAX                                        0xffff
 #define IMX290_SHS1                                    IMX290_REG_24BIT(0x3020)
@@ -109,6 +110,9 @@
 #define IMX290_PGCTRL_THRU                             BIT(1)
 #define IMX290_PGCTRL_MODE(n)                          ((n) << 4)
 
+/* Number of lines by which exposure must be less than VMAX */
+#define IMX290_EXPOSURE_OFFSET                         2
+
 #define IMX290_VMAX_DEFAULT                            1125
 
 #define IMX290_PIXEL_RATE                              148500000
@@ -225,6 +229,7 @@ struct imx290 {
        struct v4l2_ctrl *link_freq;
        struct v4l2_ctrl *hblank;
        struct v4l2_ctrl *vblank;
+       struct v4l2_ctrl *exposure;
 };
 
 static inline struct imx290 *to_imx290(struct v4l2_subdev *_sd)
@@ -238,7 +243,6 @@ static inline struct imx290 *to_imx290(struct v4l2_subdev *_sd)
 
 static const struct imx290_regval imx290_global_init_settings[] = {
        { IMX290_CTRL_07, IMX290_WINMODE_1080P },
-       { IMX290_VMAX, IMX290_VMAX_DEFAULT },
        { IMX290_EXTCK_FREQ, 0x2520 },
        { IMX290_WINWV_OB, 12 },
        { IMX290_WINPH, 0 },
@@ -664,6 +668,16 @@ static int imx290_setup_format(struct imx290 *imx290,
 /* ----------------------------------------------------------------------------
  * Controls
  */
+static void imx290_exposure_update(struct imx290 *imx290,
+                                  const struct imx290_mode *mode)
+{
+       unsigned int exposure_max;
+
+       exposure_max = imx290->vblank->val + mode->height -
+                      IMX290_EXPOSURE_OFFSET;
+       __v4l2_ctrl_modify_range(imx290->exposure, 1, exposure_max, 1,
+                                exposure_max);
+}
 
 static int imx290_set_ctrl(struct v4l2_ctrl *ctrl)
 {
@@ -671,7 +685,7 @@ static int imx290_set_ctrl(struct v4l2_ctrl *ctrl)
                                             struct imx290, ctrls);
        const struct v4l2_mbus_framefmt *format;
        struct v4l2_subdev_state *state;
-       int ret = 0;
+       int ret = 0, vmax;
 
        /*
         * Return immediately for controls that don't need to be applied to the
@@ -680,6 +694,11 @@ static int imx290_set_ctrl(struct v4l2_ctrl *ctrl)
        if (ctrl->flags & V4L2_CTRL_FLAG_READ_ONLY)
                return 0;
 
+       if (ctrl->id == V4L2_CID_VBLANK) {
+               /* Changing vblank changes the allowed range for exposure. */
+               imx290_exposure_update(imx290, imx290->current_mode);
+       }
+
        /* V4L2 controls values will be applied only when power is already up */
        if (!pm_runtime_get_if_in_use(imx290->dev))
                return 0;
@@ -692,9 +711,23 @@ static int imx290_set_ctrl(struct v4l2_ctrl *ctrl)
                ret = imx290_write(imx290, IMX290_GAIN, ctrl->val, NULL);
                break;
 
+       case V4L2_CID_VBLANK:
+               ret = imx290_write(imx290, IMX290_VMAX,
+                                  ctrl->val + imx290->current_mode->height,
+                                  NULL);
+               /*
+                * Due to the way that exposure is programmed in this sensor in
+                * relation to VMAX, we have to reprogramme it whenever VMAX is
+                * changed.
+                * Update ctrl so that the V4L2_CID_EXPOSURE case can refer to
+                * it.
+                */
+               ctrl = imx290->exposure;
+               fallthrough;
        case V4L2_CID_EXPOSURE:
+               vmax = imx290->vblank->val + imx290->current_mode->height;
                ret = imx290_write(imx290, IMX290_SHS1,
-                                  IMX290_VMAX_DEFAULT - ctrl->val - 1, NULL);
+                                  vmax - ctrl->val - 1, NULL);
                break;
 
        case V4L2_CID_TEST_PATTERN:
@@ -751,13 +784,15 @@ static void imx290_ctrl_update(struct imx290 *imx290,
 {
        unsigned int hblank_min = mode->hmax_min - mode->width;
        unsigned int hblank_max = IMX290_HMAX_MAX - mode->width;
-       unsigned int vblank = IMX290_VMAX_DEFAULT - mode->height;
+       unsigned int vblank_min = IMX290_VMAX_DEFAULT - mode->height;
+       unsigned int vblank_max = IMX290_VMAX_MAX - mode->height;
 
        __v4l2_ctrl_s_ctrl(imx290->link_freq, mode->link_freq_index);
 
        __v4l2_ctrl_modify_range(imx290->hblank, hblank_min, hblank_max, 1,
                                 hblank_min);
-       __v4l2_ctrl_modify_range(imx290->vblank, vblank, vblank, 1, vblank);
+       __v4l2_ctrl_modify_range(imx290->vblank, vblank_min, vblank_max, 1,
+                                vblank_min);
 }
 
 static int imx290_ctrl_init(struct imx290 *imx290)
@@ -787,9 +822,13 @@ static int imx290_ctrl_init(struct imx290 *imx290)
        v4l2_ctrl_new_std(&imx290->ctrls, &imx290_ctrl_ops,
                          V4L2_CID_ANALOGUE_GAIN, 0, 100, 1, 0);
 
-       v4l2_ctrl_new_std(&imx290->ctrls, &imx290_ctrl_ops,
-                         V4L2_CID_EXPOSURE, 1, IMX290_VMAX_DEFAULT - 2, 1,
-                         IMX290_VMAX_DEFAULT - 2);
+       /*
+        * Correct range will be determined through imx290_ctrl_update setting
+        * V4L2_CID_VBLANK.
+        */
+       imx290->exposure = v4l2_ctrl_new_std(&imx290->ctrls, &imx290_ctrl_ops,
+                                            V4L2_CID_EXPOSURE, 1, 65535, 1,
+                                            65535);
 
        /*
         * Set the link frequency, pixel rate, horizontal blanking and vertical
@@ -821,8 +860,6 @@ static int imx290_ctrl_init(struct imx290 *imx290)
 
        imx290->vblank = v4l2_ctrl_new_std(&imx290->ctrls, &imx290_ctrl_ops,
                                           V4L2_CID_VBLANK, 1, 1, 1, 1);
-       if (imx290->vblank)
-               imx290->vblank->flags |= V4L2_CTRL_FLAG_READ_ONLY;
 
        v4l2_ctrl_new_fwnode_properties(&imx290->ctrls, &imx290_ctrl_ops,
                                        &props);
@@ -1008,6 +1045,7 @@ static int imx290_set_fmt(struct v4l2_subdev *sd,
                imx290->current_mode = mode;
 
                imx290_ctrl_update(imx290, &fmt->format, mode);
+               imx290_exposure_update(imx290, mode);
        }
 
        *format = fmt->format;