[U-Boot] [PATCH 149/172] ddr: altera: Clean up rw_mgr_mem_calibrate_vfifo_center() part 5

Marek Vasut
2015-07-27T20:51:52Z

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>
---
drivers/ddr/altera/sequencer.c | 90 +++++++++++++++++++++---------------------
1 file changed, 44 insertions(+), 46 deletions(-)

diff --git a/drivers/ddr/altera/sequencer.c b/drivers/ddr/altera/sequencer.c
index 3db226d..d6b96f4 100644
--- 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;
--
2.1.4