From f09da11e6bf52ace14cd10d5222aab649e74a9ac Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Sat, 18 Jul 2015 02:57:32 +0200 Subject: ddr: altera: Extract DQS enable calibration from rw_mgr_mem_calibrate_vfifo() 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 --- drivers/ddr/altera/sequencer.c | 32 +++++++++++++++++++++++++++++--- 1 file changed, 29 insertions(+), 3 deletions(-) (limited to 'drivers/ddr/altera/sequencer.c') diff --git a/drivers/ddr/altera/sequencer.c b/drivers/ddr/altera/sequencer.c index 57557d3948..6fa07cf7cb 100644 --- a/drivers/ddr/altera/sequencer.c +++ b/drivers/ddr/altera/sequencer.c @@ -2234,6 +2234,31 @@ static int rw_mgr_mem_calibrate_guaranteed_write(const u32 rw_group, return 0; } +/** + * 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 @@ -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; } -- cgit v1.2.1