[PATCH v2] media: ov5640: add support of V4L2_CID_LINK_FREQ

[Hugues Fruchet]

Add support of V4L2_CID_LINK_FREQ, this is needed
by some CSI-2 receivers.

384MHz is exposed for the time being, corresponding
to 96MHz pixel clock with 2 bytes per pixel on 2 data lanes.

This setup has been tested successfully with ST MIPID02
CSI-2 to parallel bridge.

Signed-off-by: Hugues Fruchet <hugues.fruc...@st.com>
---
version 2:
  - do not set control read only as per Hans' comment:
    See https://www.mail-archive.com/linux-media@vger.kernel.org/msg147910.html

 drivers/media/i2c/ov5640.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
index 82d4ce9..e6307f3 100644
--- a/drivers/media/i2c/ov5640.c
+++ b/drivers/media/i2c/ov5640.c
@@ -218,6 +218,7 @@ struct ov5640_ctrls {
        struct v4l2_ctrl *test_pattern;
        struct v4l2_ctrl *hflip;
        struct v4l2_ctrl *vflip;
+       struct v4l2_ctrl *link_freq;
 };
 
 struct ov5640_dev {
@@ -2198,6 +2199,10 @@ static int ov5640_try_fmt_internal(struct v4l2_subdev 
*sd,
        return 0;
 }
 
+static const s64 link_freq_menu_items[] = {
+       384000000,
+};
+
 static int ov5640_set_fmt(struct v4l2_subdev *sd,
                          struct v4l2_subdev_pad_config *cfg,
                          struct v4l2_subdev_format *format)
@@ -2636,6 +2641,8 @@ static int ov5640_s_ctrl(struct v4l2_ctrl *ctrl)
        case V4L2_CID_VFLIP:
                ret = ov5640_set_ctrl_vflip(sensor, ctrl->val);
                break;
+       case V4L2_CID_LINK_FREQ:
+               return 0;
        default:
                ret = -EINVAL;
                break;
@@ -2703,6 +2710,9 @@ static int ov5640_init_controls(struct ov5640_dev *sensor)
                                       V4L2_CID_POWER_LINE_FREQUENCY_AUTO, 0,
                                       V4L2_CID_POWER_LINE_FREQUENCY_50HZ);
 
+       ctrls->link_freq = v4l2_ctrl_new_int_menu(hdl, ops, V4L2_CID_LINK_FREQ,
+                                                 0, 0, link_freq_menu_items);
+
        if (hdl->error) {
                ret = hdl->error;
                goto free_ctrls;
-- 
2.7.4