ddr: altera: Clean up rw_mgr_mem_calibrate_vfifo_center() part 5

Factor out the get_window_mid_index() for finding the best DQ
window centering. This is again code common to two stages, so
pull it out.

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

diff --git a/drivers/ddr/altera/sequencer.c b/drivers/ddr/altera/sequencer.c
index 3db226d7a8cacaafe1862f9773ee7fd9bf84e0b1..d6b96f4caad214896e07241605555e1ab02d3cff 100644 (file)
--- a/drivers/ddr/altera/sequencer.c
+++ b/drivers/ddr/altera/sequencer.c
@@ -2073,6 +2073,48 @@ static int search_right_edge(const int write, const int rank_bgn,
        return 0;
 }
 
+/**
+ * get_window_mid_index() - Find the best middle setting of DQ/DQS phase
+ * @write:             Perform read (Stage 2) or write (Stage 3) calibration
+ * @left_edge:         Left edge of the DQ/DQS phase
+ * @right_edge:                Right edge of the DQ/DQS phase
+ * @mid_min:           Best DQ/DQS phase middle setting
+ *
+ * Find index and value of the middle of the DQ/DQS working phase.
+ */
+static int get_window_mid_index(const int write, int *left_edge,
+                               int *right_edge, int *mid_min)
+{
+       const u32 per_dqs = write ? RW_MGR_MEM_DQ_PER_WRITE_DQS :
+                                   RW_MGR_MEM_DQ_PER_READ_DQS;
+       int i, mid, min_index;
+
+       /* Find middle of window for each DQ bit */
+       *mid_min = left_edge[0] - right_edge[0];
+       min_index = 0;
+       for (i = 1; i < per_dqs; i++) {
+               mid = left_edge[i] - right_edge[i];
+               if (mid < *mid_min) {
+                       *mid_min = mid;
+                       min_index = i;
+               }
+       }
+
+       /*
+        * -mid_min/2 represents the amount that we need to move DQS.
+        * If mid_min is odd and positive we'll need to add one to make
+        * sure the rounding in further calculations is correct (always
+        * bias to the right), so just add 1 for all positive values.
+        */
+       if (*mid_min > 0)
+               (*mid_min)++;
+       *mid_min = *mid_min / 2;
+
+       debug_cond(DLEVEL == 1, "%s:%d vfifo_center: *mid_min=%d (index=%u)\n",
+                  __func__, __LINE__, *mid_min, min_index);
+       return min_index;
+}
+
 /* per-bit deskew DQ and center */
 static uint32_t rw_mgr_mem_calibrate_vfifo_center(uint32_t rank_bgn,
        uint32_t write_group, uint32_t read_group, uint32_t test_bgn,
@@ -2155,30 +2197,7 @@ static uint32_t rw_mgr_mem_calibrate_vfifo_center(uint32_t rank_bgn,
                return 0;
        }
 
-       /* Find middle of window for each DQ bit */
-       mid_min = left_edge[0] - right_edge[0];
-       min_index = 0;
-       for (i = 1; i < RW_MGR_MEM_DQ_PER_READ_DQS; i++) {
-               mid = left_edge[i] - right_edge[i];
-               if (mid < mid_min) {
-                       mid_min = mid;
-                       min_index = i;
-               }
-       }
-
-       /*
-        * -mid_min/2 represents the amount that we need to move DQS.
-        * If mid_min is odd and positive we'll need to add one to
-        * make sure the rounding in further calculations is correct
-        * (always bias to the right), so just add 1 for all positive values.
-        */
-       if (mid_min > 0)
-               mid_min++;
-
-       mid_min = mid_min / 2;
-
-       debug_cond(DLEVEL == 1, "%s:%d vfifo_center: mid_min=%d (index=%u)\n",
-                  __func__, __LINE__, mid_min, min_index);
+       min_index = get_window_mid_index(0, left_edge, right_edge, &mid_min);
 
        /* Determine the amount we can change DQS (which is -mid_min) */
        orig_mid_min = mid_min;
@@ -2888,28 +2907,7 @@ static uint32_t rw_mgr_mem_calibrate_writes_center(uint32_t rank_bgn,
                return 0;
        }
 
-       /* Find middle of window for each DQ bit */
-       mid_min = left_edge[0] - right_edge[0];
-       min_index = 0;
-       for (i = 1; i < RW_MGR_MEM_DQ_PER_WRITE_DQS; i++) {
-               mid = left_edge[i] - right_edge[i];
-               if (mid < mid_min) {
-                       mid_min = mid;
-                       min_index = i;
-               }
-       }
-
-       /*
-        * -mid_min/2 represents the amount that we need to move DQS.
-        * If mid_min is odd and positive we'll need to add one to
-        * make sure the rounding in further calculations is correct
-        * (always bias to the right), so just add 1 for all positive values.
-        */
-       if (mid_min > 0)
-               mid_min++;
-       mid_min = mid_min / 2;
-       debug_cond(DLEVEL == 1, "%s:%d write_center: mid_min=%d\n", __func__,
-                  __LINE__, mid_min);
+       min_index = get_window_mid_index(1, left_edge, right_edge, &mid_min);
 
        /* Determine the amount we can change DQS (which is -mid_min) */
        orig_mid_min = mid_min;