[U-Boot] [PATCH 106/172] ddr: altera: Extract DQS enable calibration from rw_mgr_mem_calibrate_vfifo()

Marek Vasut
2015-07-27T20:51:09Z

Just extract this piece of functionality into separate function
to make the code better separated. This matches the division in
Altera documentation, Altera EMI_RM 2015.05.04 , section 1, the
UniPHY Calibration Stages.

Signed-off-by: Marek Vasut <marex@denx.de>
---
drivers/ddr/altera/sequencer.c | 32 +++++++++++++++++++++++++++++---
1 file changed, 29 insertions(+), 3 deletions(-)

diff --git a/drivers/ddr/altera/sequencer.c b/drivers/ddr/altera/sequencer.c
index 57557d3..6fa07cf 100644
--- a/drivers/ddr/altera/sequencer.c
+++ b/drivers/ddr/altera/sequencer.c
@@ -2235,6 +2235,31 @@ static int rw_mgr_mem_calibrate_guaranteed_write(const u32 rw_group,
}

/**
+ * rw_mgr_mem_calibrate_dqs_enable_calibration() - DQS Enable Calibration
+ * @rw_group: Read/Write Group
+ * @test_bgn: Rank at which the test begins
+ *
+ * DQS enable calibration ensures reliable capture of the DQ signal without
+ * glitches on the DQS line.
+ */
+static int rw_mgr_mem_calibrate_dqs_enable_calibration(const u32 rw_group,
+ const u32 test_bgn)
+{
+ int ret;
+
+ /*
+ * Altera EMI_RM 2015.05.04 :: Figure 1-27
+ * DQS and DQS Eanble Signal Relationships.
+ */
+ ret = rw_mgr_mem_calibrate_vfifo_find_dqs_en_phase_sweep_dq_in_delay(
+ rw_group, rw_group, test_bgn);
+ if (!ret) /* FIXME: 0 means failure in this old code :-( */
+ return -EIO;
+
+ return 0;
+}
+
+/**
* rw_mgr_mem_calibrate_vfifo() - Calibrate the read valid prediction FIFO
* @rw_group: Read/Write Group
* @test_bgn: Rank at which the test begins
@@ -2289,9 +2314,10 @@ static int rw_mgr_mem_calibrate_vfifo(const u32 rw_group, const u32 test_bgn)
if (ret)
break;

- /* case:56390 */
- if (!rw_mgr_mem_calibrate_vfifo_find_dqs_en_phase_sweep_dq_in_delay
- (rw_group, rw_group, test_bgn)) {
+ /* 2) DQS Enable Calibration */
+ ret = rw_mgr_mem_calibrate_dqs_enable_calibration(rw_group,
+ test_bgn);
+ if (ret) {
failed_substage = CAL_SUBSTAGE_DQS_EN_PHASE;
continue;
}
--
2.1.4