From daf2cb7d396e711da5e172b856be253e8f0eb139 Mon Sep 17 00:00:00 2001
From: Florent Kermarrec <florent@enjoy-digital.fr>
Date: Thu, 8 Jul 2021 09:02:13 +0200
Subject: [PATCH] phy/model: Integrate
 sdram_module_nphases/get_sdram_phy_settings from litex_sim.

---
 litedram/phy/model.py | 71 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 70 insertions(+), 1 deletion(-)

diff --git a/litedram/phy/model.py b/litedram/phy/model.py
index 93000bd..9796c9e 100644
--- a/litedram/phy/model.py
+++ b/litedram/phy/model.py
@@ -11,7 +11,7 @@
 
 from migen import *
 
-from litedram.common import burst_lengths
+from litedram.common import burst_lengths, PhySettings
 from litedram.phy.dfi import *
 from litedram.modules import _speedgrade_timings, _technology_timings
 
@@ -376,6 +376,75 @@ class DFITimingsChecker(Module):
                 )
             ]
 
+# SDRAM PHY Settings -------------------------------------------------------------------------------
+
+sdram_module_nphases = {
+    "SDR":   1,
+    "DDR":   2,
+    "LPDDR": 2,
+    "DDR2":  2,
+    "DDR3":  4,
+    "DDR4":  4,
+}
+
+def get_sdram_phy_settings(memtype, data_width, clk_freq):
+    nphases = sdram_module_nphases[memtype]
+
+    if memtype == "SDR":
+        # Settings from gensdrphy
+        rdphase       = 0
+        wrphase       = 0
+        cl            = 2
+        cwl           = None
+        read_latency  = 4
+        write_latency = 0
+    elif memtype in ["DDR", "LPDDR"]:
+        # Settings from s6ddrphy
+        rdphase       = 0
+        wrphase       = 1
+        cl            = 3
+        cwl           = None
+        read_latency  = 5
+        write_latency = 0
+    elif memtype in ["DDR2", "DDR3"]:
+        # Settings from s7ddrphy
+        tck             = 2/(2*nphases*clk_freq)
+        cl, cwl         = get_default_cl_cwl(memtype, tck)
+        cl_sys_latency  = get_sys_latency(nphases, cl)
+        cwl_sys_latency = get_sys_latency(nphases, cwl)
+        rdphase         = get_sys_phase(nphases, cl_sys_latency, cl)
+        wrphase         = get_sys_phase(nphases, cwl_sys_latency, cwl)
+        read_latency    = cl_sys_latency + 6
+        write_latency   = cwl_sys_latency - 1
+    elif memtype == "DDR4":
+        # Settings from usddrphy
+        tck             = 2/(2*nphases*clk_freq)
+        cl, cwl         = get_default_cl_cwl(memtype, tck)
+        cl_sys_latency  = get_sys_latency(nphases, cl)
+        cwl_sys_latency = get_sys_latency(nphases, cwl)
+        rdphase         = get_sys_phase(nphases, cl_sys_latency, cl)
+        wrphase         = get_sys_phase(nphases, cwl_sys_latency, cwl)
+        read_latency    = cl_sys_latency + 5
+        write_latency   = cwl_sys_latency - 1
+
+    sdram_phy_settings = {
+        "nphases":       nphases,
+        "rdphase":       rdphase,
+        "wrphase":       wrphase,
+        "cl":            cl,
+        "cwl":           cwl,
+        "read_latency":  read_latency,
+        "write_latency": write_latency,
+    }
+
+    return PhySettings(
+        phytype      = "SDRAMPHYModel",
+        memtype      = memtype,
+        databits     = data_width,
+        dfi_databits = data_width if memtype == "SDR" else 2*data_width,
+        **sdram_phy_settings,
+    )
+
 # SDRAM PHY Model ----------------------------------------------------------------------------------
 
 class SDRAMPHYModel(Module):