diff options
| author | Marek Vasut <marex@denx.de> | 2015-07-19 04:04:33 +0200 |
|---|---|---|
| committer | Marek Vasut <marex@denx.de> | 2015-08-08 14:14:18 +0200 |
| commit | cbb0b7e03641bbeea558b7d0497d0267578459a2 (patch) | |
| tree | fe1dc9785ba0284a662268c23a48b08f050a4528 /drivers | |
| parent | 28fd242a18f78ea9f3c208e9180ecaed76cfb83d (diff) | |
ddr: altera: Clean up sdr_find_window_centre() part 2
This function is a treasure trove of ad-hoc iterative
implementations of mathematical functions. Replace all
of those with their non-iterative counterpart.
Signed-off-by: Marek Vasut <marex@denx.de>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/ddr/altera/sequencer.c | 31 |
1 files changed, 15 insertions, 16 deletions
diff --git a/drivers/ddr/altera/sequencer.c b/drivers/ddr/altera/sequencer.c index 4c4b36ce50..eb246cc89d 100644 --- a/drivers/ddr/altera/sequencer.c +++ b/drivers/ddr/altera/sequencer.c @@ -1492,28 +1492,27 @@ static int sdr_find_window_centre(const u32 grp, const u32 work_bgn, debug_cond(DLEVEL == 2, "work_bgn=%d work_end=%d work_mid=%d\n", work_bgn, work_end, work_mid); /* Get the middle delay to be less than a VFIFO delay */ - for (p = 0; p <= IO_DQS_EN_PHASE_MAX; - p++, tmp_delay += IO_DELAY_PER_OPA_TAP) - ; + tmp_delay = (IO_DQS_EN_PHASE_MAX + 1) * IO_DELAY_PER_OPA_TAP; debug_cond(DLEVEL == 2, "vfifo ptap delay %d\n", tmp_delay); - while (work_mid > tmp_delay) - work_mid -= tmp_delay; + work_mid %= tmp_delay; debug_cond(DLEVEL == 2, "new work_mid %d\n", work_mid); - tmp_delay = 0; - for (p = 0; p <= IO_DQS_EN_PHASE_MAX && tmp_delay < work_mid; - p++, tmp_delay += IO_DELAY_PER_OPA_TAP) - ; - tmp_delay -= IO_DELAY_PER_OPA_TAP; - debug_cond(DLEVEL == 2, "new p %d, tmp_delay=%d\n", p - 1, tmp_delay); + tmp_delay = rounddown(work_mid, IO_DELAY_PER_OPA_TAP); + if (tmp_delay > IO_DQS_EN_PHASE_MAX * IO_DELAY_PER_OPA_TAP) + tmp_delay = IO_DQS_EN_PHASE_MAX * IO_DELAY_PER_OPA_TAP; + p = tmp_delay / IO_DELAY_PER_OPA_TAP; + + debug_cond(DLEVEL == 2, "new p %d, tmp_delay=%d\n", p, tmp_delay); + + d = DIV_ROUND_UP(work_mid - tmp_delay, IO_DELAY_PER_DQS_EN_DCHAIN_TAP); + if (d > IO_DQS_EN_DELAY_MAX) + d = IO_DQS_EN_DELAY_MAX; + tmp_delay += d * IO_DELAY_PER_DQS_EN_DCHAIN_TAP; - for (d = 0; d <= IO_DQS_EN_DELAY_MAX && tmp_delay < work_mid; - d++, tmp_delay += IO_DELAY_PER_DQS_EN_DCHAIN_TAP) - ; debug_cond(DLEVEL == 2, "new d %d, tmp_delay=%d\n", d, tmp_delay); - scc_mgr_set_dqs_en_phase_all_ranks(grp, p - 1); + scc_mgr_set_dqs_en_phase_all_ranks(grp, p); scc_mgr_set_dqs_en_delay_all_ranks(grp, d); /* @@ -1540,7 +1539,7 @@ static int sdr_find_window_centre(const u32 grp, const u32 work_bgn, } else { debug_cond(DLEVEL == 2, "%s:%d center: found: vfifo=%u ptap=%u dtap=%u\n", - __func__, __LINE__, v, p - 1, d); + __func__, __LINE__, v, p, d); return 1; } } |