nb/intel/sandybridge: Clean up program_timings
Clarify the clock, command and control programming sequence.
Tested on Asus P8Z77-V LX2, still boots.
Change-Id: I1aa4144197dc25dc8d6ef1d23e465280bddd95a3
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/47770
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/northbridge/intel/sandybridge/raminit_common.c b/src/northbridge/intel/sandybridge/raminit_common.c
index 80c5186..7252574 100644
--- a/src/northbridge/intel/sandybridge/raminit_common.c
+++ b/src/northbridge/intel/sandybridge/raminit_common.c
@@ -934,71 +934,88 @@
void program_timings(ramctr_timing *ctrl, int channel)
{
- u32 reg_roundtrip_latency, reg_pi_code, reg_logic_delay, reg_io_latency;
+ u32 reg_roundtrip_latency, reg_io_latency;
int lane;
int slotrank, slot;
- int full_shift = 0;
- u16 pi_coding_ctrl[NUM_SLOTS];
+ u32 ctl_delay[NUM_SLOTS] = { 0 };
+ int cmd_delay = 0;
+
+ /* Enable CLK XOVER */
+ u32 clk_pi_coding = get_XOVER_CLK(ctrl->rankmap[channel]);
+ u32 clk_logic_dly = 0;
+
+ /*
+ * Apply command delay if desired setting is negative. Find the
+ * most negative value: 'cmd_delay' will be the absolute value.
+ */
FOR_ALL_POPULATED_RANKS {
- if (full_shift < -ctrl->timings[channel][slotrank].pi_coding)
- full_shift = -ctrl->timings[channel][slotrank].pi_coding;
+ if (cmd_delay < -ctrl->timings[channel][slotrank].pi_coding)
+ cmd_delay = -ctrl->timings[channel][slotrank].pi_coding;
+ }
+ if (cmd_delay < 0) {
+ printk(BIOS_ERR, "C%d command delay underflow: %d\n", channel, cmd_delay);
+ cmd_delay = 0;
+ }
+ if (cmd_delay >= 128) {
+ printk(BIOS_ERR, "C%d command delay overflow: %d\n", channel, cmd_delay);
+ cmd_delay = 127;
}
- for (slot = 0; slot < NUM_SLOTS; slot++)
- switch ((ctrl->rankmap[channel] >> (2 * slot)) & 3) {
- case 0:
- default:
- pi_coding_ctrl[slot] = 0x7f;
- break;
- case 1:
- pi_coding_ctrl[slot] =
- ctrl->timings[channel][2 * slot + 0].pi_coding + full_shift;
- break;
- case 2:
- pi_coding_ctrl[slot] =
- ctrl->timings[channel][2 * slot + 1].pi_coding + full_shift;
- break;
- case 3:
- pi_coding_ctrl[slot] =
- (ctrl->timings[channel][2 * slot].pi_coding +
- ctrl->timings[channel][2 * slot + 1].pi_coding) / 2 + full_shift;
- break;
+ /* Apply control and clock delay if desired setting is positive */
+ if (cmd_delay == 0) {
+ for (slot = 0; slot < NUM_SLOTS; slot++) {
+ const int pi_coding_0 = ctrl->timings[channel][2 * slot + 0].pi_coding;
+ const int pi_coding_1 = ctrl->timings[channel][2 * slot + 1].pi_coding;
+
+ const u8 slot_map = (ctrl->rankmap[channel] >> (2 * slot)) & 3;
+
+ if (slot_map & 1)
+ ctl_delay[slot] += pi_coding_0 + cmd_delay;
+
+ if (slot_map & 2)
+ ctl_delay[slot] += pi_coding_1 + cmd_delay;
+
+ /* If both ranks in a slot are populated, use the average */
+ if (slot_map == 3)
+ ctl_delay[slot] /= 2;
+
+ if (ctl_delay[slot] >= 128) {
+ printk(BIOS_ERR, "C%dS%d control delay overflow: %d\n",
+ channel, slot, ctl_delay[slot]);
+ ctl_delay[slot] = 127;
+ }
}
+ FOR_ALL_POPULATED_RANKS {
+ u32 clk_delay = ctrl->timings[channel][slotrank].pi_coding + cmd_delay;
+
+ if (clk_delay >= 128) {
+ printk(BIOS_ERR, "C%dR%d clock delay overflow: %d\n",
+ channel, slotrank, clk_delay);
+ clk_delay = 127;
+ }
+
+ clk_pi_coding |= (clk_delay % 64) << (6 * slotrank);
+ clk_logic_dly |= (clk_delay / 64) << slotrank;
+ }
+ }
/* Enable CMD XOVER */
union gdcr_cmd_pi_coding_reg cmd_pi_coding = {
.raw = get_XOVER_CMD(ctrl->rankmap[channel]),
};
- cmd_pi_coding.cmd_pi_code = full_shift & 0x3f;
- cmd_pi_coding.cmd_logic_delay = !!(full_shift & 0x40);
+ cmd_pi_coding.cmd_pi_code = cmd_delay % 64;
+ cmd_pi_coding.cmd_logic_delay = cmd_delay / 64;
- cmd_pi_coding.ctl_pi_code_d0 = pi_coding_ctrl[0] & 0x3f;
- cmd_pi_coding.ctl_pi_code_d1 = pi_coding_ctrl[1] & 0x3f;
- cmd_pi_coding.ctl_logic_delay_d0 = !!(pi_coding_ctrl[0] & 0x40);
- cmd_pi_coding.ctl_logic_delay_d1 = !!(pi_coding_ctrl[1] & 0x40);
+ cmd_pi_coding.ctl_pi_code_d0 = ctl_delay[0] % 64;
+ cmd_pi_coding.ctl_pi_code_d1 = ctl_delay[1] % 64;
+ cmd_pi_coding.ctl_logic_delay_d0 = ctl_delay[0] / 64;
+ cmd_pi_coding.ctl_logic_delay_d1 = ctl_delay[1] / 64;
MCHBAR32(GDCRCMDPICODING_ch(channel)) = cmd_pi_coding.raw;
- /* Enable CLK XOVER */
- reg_pi_code = get_XOVER_CLK(ctrl->rankmap[channel]);
- reg_logic_delay = 0;
-
- FOR_ALL_POPULATED_RANKS {
- int shift = ctrl->timings[channel][slotrank].pi_coding + full_shift;
- int offset_pi_code;
- if (shift < 0)
- shift = 0;
-
- offset_pi_code = ctrl->pi_code_offset + shift;
-
- /* Set CLK phase shift */
- reg_pi_code |= (offset_pi_code & 0x3f) << (6 * slotrank);
- reg_logic_delay |= ((offset_pi_code >> 6) & 1) << slotrank;
- }
-
- MCHBAR32(GDCRCKPICODE_ch(channel)) = reg_pi_code;
- MCHBAR32(GDCRCKLOGICDELAY_ch(channel)) = reg_logic_delay;
+ MCHBAR32(GDCRCKPICODE_ch(channel)) = clk_pi_coding;
+ MCHBAR32(GDCRCKLOGICDELAY_ch(channel)) = clk_logic_dly;
reg_io_latency = MCHBAR32(SC_IO_LATENCY_ch(channel));
reg_io_latency &= ~0xffff;
@@ -1009,7 +1026,7 @@
int post_timA_min_high = 7, pre_timA_min_high = 7;
int post_timA_max_high = 0, pre_timA_max_high = 0;
int shift_402x = 0;
- int shift = ctrl->timings[channel][slotrank].pi_coding + full_shift;
+ int shift = ctrl->timings[channel][slotrank].pi_coding + cmd_delay;
if (shift < 0)
shift = 0;