[U-Boot] [PATCH 157/172] ddr: altera: Clean up rw_mgr_mem_calibrate_writes_center() part 2

Marek Vasut
2015-07-27T20:52:00Z

Factor out common code for searching best DM/DQS window.

Signed-off-by: Marek Vasut <marex@denx.de>
---
drivers/ddr/altera/sequencer.c | 167 ++++++++++++++++++++++-------------------
1 file changed, 88 insertions(+), 79 deletions(-)

diff --git a/drivers/ddr/altera/sequencer.c b/drivers/ddr/altera/sequencer.c
index e99ecb4..cc5db16 100644
--- a/drivers/ddr/altera/sequencer.c
+++ b/drivers/ddr/altera/sequencer.c
@@ -2883,6 +2883,89 @@ static uint32_t rw_mgr_mem_calibrate_write_test(uint32_t rank_bgn,
}
}

+/**
+ * search_window() - Search for the/part of the window with DM/DQS shift
+ * @search_dm: If 1, search for the DM shift, if 0, search for DQS shift
+ * @rank_bgn: Rank number
+ * @write_group: Write Group
+ * @bgn_curr: Current window begin
+ * @end_curr: Current window end
+ * @bgn_best: Current best window begin
+ * @end_best: Current best window end
+ * @win_best: Size of the best window
+ * @new_dqs: New DQS value (only applicable if search_dm = 0).
+ *
+ * Search for the/part of the window with DM/DQS shift.
+ */
+static void search_window(const int search_dm,
+ const u32 rank_bgn, const u32 write_group,
+ int *bgn_curr, int *end_curr, int *bgn_best,
+ int *end_best, int *win_best, int new_dqs)
+{
+ u32 bit_chk;
+ const int max = IO_IO_OUT1_DELAY_MAX - new_dqs;
+ int d, di;
+
+ /* Search for the/part of the window with DM/DQS shift. */
+ for (di = max; di >= 0; di -= DELTA_D) {
+ if (search_dm) {
+ d = di;
+ scc_mgr_apply_group_dm_out1_delay(d);
+ } else {
+ /* For DQS, we go from 0...max */
+ d = max - di;
+ /*
+ * Note: This only shifts DQS, so are we limiting ourselve to
+ * width of DQ unnecessarily.
+ */
+ scc_mgr_apply_group_dqs_io_and_oct_out1(write_group,
+ d + new_dqs);
+ }
+
+ writel(0, &sdr_scc_mgr->update);
+
+ if (rw_mgr_mem_calibrate_write_test(rank_bgn, write_group, 1,
+ PASS_ALL_BITS, &bit_chk,
+ 0)) {
+ /* Set current end of the window. */
+ *end_curr = search_dm ? -d : d;
+
+ /*
+ * If a starting edge of our window has not been seen
+ * this is our current start of the DM window.
+ */
+ if (*bgn_curr == IO_IO_OUT1_DELAY_MAX + 1)
+ *bgn_curr = search_dm ? -d : d;
+
+ /*
+ * If current window is bigger than best seen.
+ * Set best seen to be current window.
+ */
+ if ((*end_curr - *bgn_curr + 1) > *win_best) {
+ *win_best = *end_curr - *bgn_curr + 1;
+ *bgn_best = *bgn_curr;
+ *end_best = *end_curr;
+ }
+ } else {
+ /* We just saw a failing test. Reset temp edge. */
+ *bgn_curr = IO_IO_OUT1_DELAY_MAX + 1;
+ *end_curr = IO_IO_OUT1_DELAY_MAX + 1;
+
+ /* Early exit is only applicable to DQS. */
+ if (search_dm)
+ continue;
+
+ /*
+ * Early exit optimization: if the remaining delay
+ * chain space is less than already seen largest
+ * window we can exit.
+ */
+ if (*win_best - 1 > IO_IO_OUT1_DELAY_MAX - new_dqs - d)
+ break;
+ }
+ }
+}
+
/*
* center all windows. do per-bit-deskew to possibly increase size of
* certain windows.
@@ -2891,8 +2974,7 @@ static int
rw_mgr_mem_calibrate_writes_center(const u32 rank_bgn, const u32 write_group,
const u32 test_bgn)
{
- int i, d;
- u32 bit_chk;
+ int i;
u32 sticky_bit_chk;
u32 min_index;
u32 addr;
@@ -2975,37 +3057,8 @@ rw_mgr_mem_calibrate_writes_center(const u32 rank_bgn, const u32 write_group,
right_edge[0] = IO_IO_OUT1_DELAY_MAX + 1;

/* Search for the/part of the window with DM shift. */
- for (d = IO_IO_OUT1_DELAY_MAX; d >= 0; d -= DELTA_D) {
- scc_mgr_apply_group_dm_out1_delay(d);
- writel(0, &sdr_scc_mgr->update);
-
- if (rw_mgr_mem_calibrate_write_test(rank_bgn, write_group, 1,
- PASS_ALL_BITS, &bit_chk,
- 0)) {
- /* Set current end of the window. */
- end_curr = -d;
- /*
- * If a starting edge of our window has not been seen
- * this is our current start of the DM window.
- */
- if (bgn_curr == IO_IO_OUT1_DELAY_MAX + 1)
- bgn_curr = -d;
-
- /*
- * If current window is bigger than best seen.
- * Set best seen to be current window.
- */
- if ((end_curr-bgn_curr+1) > win_best) {
- win_best = end_curr-bgn_curr+1;
- bgn_best = bgn_curr;
- end_best = end_curr;
- }
- } else {
- /* We just saw a failing test. Reset temp edge. */
- bgn_curr = IO_IO_OUT1_DELAY_MAX + 1;
- end_curr = IO_IO_OUT1_DELAY_MAX + 1;
- }
- }
+ search_window(1, rank_bgn, write_group, &bgn_curr, &end_curr,
+ &bgn_best, &end_best, &win_best, 0);

/* Reset DM delay chains to 0. */
scc_mgr_apply_group_dm_out1_delay(0);
@@ -3021,52 +3074,8 @@ rw_mgr_mem_calibrate_writes_center(const u32 rank_bgn, const u32 write_group,
}

/* Search for the/part of the window with DQS shifts. */
- for (d = 0; d <= IO_IO_OUT1_DELAY_MAX - new_dqs; d += DELTA_D) {
- /*
- * Note: This only shifts DQS, so are we limiting ourselve to
- * width of DQ unnecessarily.
- */
- scc_mgr_apply_group_dqs_io_and_oct_out1(write_group,
- d + new_dqs);
-
- writel(0, &sdr_scc_mgr->update);
- if (rw_mgr_mem_calibrate_write_test(rank_bgn, write_group, 1,
- PASS_ALL_BITS, &bit_chk,
- 0)) {
- /* Set current end of the window. */
- end_curr = d;
- /*
- * If a beginning edge of our window has not been seen
- * this is our current begin of the DM window.
- */
- if (bgn_curr == IO_IO_OUT1_DELAY_MAX + 1)
- bgn_curr = d;
-
- /*
- * If current window is bigger than best seen. Set best
- * seen to be current window.
- */
- if ((end_curr-bgn_curr+1) > win_best) {
- win_best = end_curr-bgn_curr+1;
- bgn_best = bgn_curr;
- end_best = end_curr;
- }
- } else {
- /* We just saw a failing test. Reset temp edge. */
- bgn_curr = IO_IO_OUT1_DELAY_MAX + 1;
- end_curr = IO_IO_OUT1_DELAY_MAX + 1;
-
- /*
- * Early exit optimization: if the remaining delay
- * chain space is less than already seen largest
- * window we can exit.
- */
- if ((win_best-1) >
- (IO_IO_OUT1_DELAY_MAX - new_dqs - d)) {
- break;
- }
- }
- }
+ search_window(0, rank_bgn, write_group, &bgn_curr, &end_curr,
+ &bgn_best, &end_best, &win_best, new_dqs);

/* Assign left and right edge for cal and reporting. */
left_edge[0] = -1 * bgn_best;
--
2.1.4