ddr: altera: Clean up find_vfifo_read()

Fix data types, constify where applicable, fix comments and debug
strings. In case enough failing reads are detected, just return
right away instead of breaking from the loop. This lets us make
the error handling at the end much simpler.

Signed-off-by: Marek Vasut <marex@denx.de>

drivers/ddr/altera/sequencer.c

@@ -1311,36 +1311,35 @@ static void rw_mgr_decr_vfifo(const u32 grp)
 		rw_mgr_incr_vfifo(grp);
 }
 
-static int find_vfifo_read(uint32_t grp, uint32_t *bit_chk)
+/**
+ * find_vfifo_failing_read() - Push VFIFO to get a failing read
+ * @grp:	Read/Write group
+ *
+ * Push VFIFO until a failing read happens.
+ */
+static int find_vfifo_failing_read(const u32 grp)
 {
-	uint32_t v;
-	uint32_t fail_cnt = 0;
-	uint32_t test_status;
+	u32 v, ret, bit_chk, fail_cnt = 0;
 
 	for (v = 0; v < VFIFO_SIZE; v++) {
-		debug_cond(DLEVEL == 2, "%s:%d find_dqs_en_phase: vfifo %u\n",
+		debug_cond(DLEVEL == 2, "%s:%d: vfifo %u\n",
 			   __func__, __LINE__, v);
-		test_status = rw_mgr_mem_calibrate_read_test_all_ranks
-			(grp, 1, PASS_ONE_BIT, bit_chk, 0);
-		if (!test_status) {
+		ret = rw_mgr_mem_calibrate_read_test_all_ranks(grp, 1,
+						PASS_ONE_BIT, &bit_chk, 0);
+		if (!ret) {
 			fail_cnt++;
 
 			if (fail_cnt == 2)
-				break;
+				return v;
 		}
 
-		/* fiddle with FIFO */
+		/* Fiddle with FIFO. */
 		rw_mgr_incr_vfifo(grp);
 	}
 
-	if (v >= VFIFO_SIZE) {
-		/* no failing read found!! Something must have gone wrong */
-		debug_cond(DLEVEL == 2, "%s:%d find_dqs_en_phase: vfifo failed\n",
-			   __func__, __LINE__);
-		return 0;
-	} else {
-		return v;
-	}
+	/* No failing read found! Something must have gone wrong. */
+	debug_cond(DLEVEL == 2, "%s:%d: vfifo failed\n", __func__, __LINE__);
+	return 0;
 }
 
 /**
@@ -1588,7 +1587,7 @@ static uint32_t rw_mgr_mem_calibrate_vfifo_find_dqs_en_phase(uint32_t grp)
 
 	/* ********************************************************* */
 	/* * Step 1 : First push vfifo until we get a failing read * */
-	find_vfifo_read(grp, &bit_chk);
+	find_vfifo_failing_read(grp);
 
 	/* ******************************************************** */
 	/* * step 2: find first working phase, increment in ptaps * */