fpga: xilinx: Check if fpga operations are defined

Ensure that operations are correctly setup.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/fpga/xilinx.c b/drivers/fpga/xilinx.c
index adb4b8c..9c95148 100644
--- a/drivers/fpga/xilinx.c
+++ b/drivers/fpga/xilinx.c
@@ -139,6 +139,11 @@
 		return FPGA_FAIL;
 	}
 
+	if (!desc->operations || !desc->operations->load) {
+		printf("%s: Missing load operation\n", __func__);
+		return FPGA_FAIL;
+	}
+
 	return desc->operations->load(desc, buf, bsize, bstype);
 }
 
@@ -151,8 +156,10 @@
 		return FPGA_FAIL;
 	}
 
-	if (!desc->operations->loadfs)
+	if (!desc->operations || !desc->operations->loadfs) {
+		printf("%s: Missing loadfs operation\n", __func__);
 		return FPGA_FAIL;
+	}
 
 	return desc->operations->loadfs(desc, buf, bsize, fpga_fsinfo);
 }
@@ -165,6 +172,11 @@
 		return FPGA_FAIL;
 	}
 
+	if (!desc->operations || !desc->operations->dump) {
+		printf("%s: Missing dump operation\n", __func__);
+		return FPGA_FAIL;
+	}
+
 	return desc->operations->dump(desc, buf, bsize);
 }
 
@@ -228,7 +240,8 @@
 
 		if (desc->iface_fns) {
 			printf ("Device Function Table @ 0x%p\n", desc->iface_fns);
-			desc->operations->info(desc);
+			if (desc->operations && desc->operations->info)
+				desc->operations->info(desc);
 		} else
 			printf ("No Device Function Table.\n");