gpu: ipu-csi: Check for field type alternate

When the CSI is receiving from a bt.656 bus, include a check for
field type 'alternate' when determining whether to set CSI clock
mode to CCIR656_INTERLACED or CCIR656_PROGRESSIVE.

Signed-off-by: Steve Longerbeam <steve_longerbeam@mentor.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

drivers/gpu/ipu-v3/ipu-csi.c

@@ -339,7 +339,8 @@ static void fill_csi_bus_cfg(struct ipu_csi_bus_config *csicfg,
 		break;
 	case V4L2_MBUS_BT656:
 		csicfg->ext_vsync = 0;
-		if (V4L2_FIELD_HAS_BOTH(mbus_fmt->field))
+		if (V4L2_FIELD_HAS_BOTH(mbus_fmt->field) ||
+		    mbus_fmt->field == V4L2_FIELD_ALTERNATE)
 			csicfg->clk_mode = IPU_CSI_CLK_MODE_CCIR656_INTERLACED;
 		else
 			csicfg->clk_mode = IPU_CSI_CLK_MODE_CCIR656_PROGRESSIVE;