Fix two bugs for MPC83xx DDR2 controller SPD Init
There are a few bugs in the cpu/mpc83xx/spd_sdram.c
the first bug is that the picos_to_clk routine introduces a huge
rounding error in 83xx.
the second bug is that the mode register write recovery field is
tWR-1, not tWR >> 1.
diff --git a/cpu/mpc83xx/spd_sdram.c b/cpu/mpc83xx/spd_sdram.c
index d9b8753..41a1f1f 100644
--- a/cpu/mpc83xx/spd_sdram.c
+++ b/cpu/mpc83xx/spd_sdram.c
@@ -58,8 +58,8 @@
int clks;
ddr_bus_clk = gd->ddr_clk >> 1;
- clks = picos / ((1000000000 / ddr_bus_clk) * 1000);
- if (picos % ((1000000000 / ddr_bus_clk) * 1000) != 0)
+ clks = picos / (1000000000 / (ddr_bus_clk / 1000));
+ if (picos % (1000000000 / (ddr_bus_clk / 1000)) != 0)
clks++;
return clks;
@@ -624,7 +624,7 @@
| (1 << (16 + 10)) /* DQS Differential disable */
| (add_lat << (16 + 3)) /* Additive Latency in EMRS1 */
| (mode_odt_enable << 16) /* ODT Enable in EMRS1 */
- | ((twr_clk >> 1) << 9) /* Write Recovery Autopre */
+ | ((twr_clk - 1) << 9) /* Write Recovery Autopre */
| (caslat << 4) /* caslat */
| (burstlen << 0) /* Burst length */
);