tegra124: fix and fine tune the warm boot code

We assume that the clock rate of SCLK/HCLK/PCLK was 408MHz which was same
as PLLP. But that is incorrect, BootROM had switched it to pllp_out2
with the rate 204MHz. So actually the warm boot procedure was running at
the condition of SCLK=HCLK=PCLK=pllp_out2 with the rate 204MHz.

And the CPU complex power on sequences were different with what we used
in kernel and Coreboot. Fix up the sequence as below.
* enable CPU clk
* power on CPU complex
* remove I/O clamps
* remove CPU reset

Update the time of the CPU complex power on function for record.
* power_on_partition(PARTID_CRAIL): 528 uSec
* power_on_partition(PARTID_CONC): 0 uSec
* power_on_partition(PARTID_CE0): 4 uSec

Finally, removing the redundant routine of a flow controller event with
(20 | MSEC_EVENT | MODE_STOP).

BUG=chrome-os-partner:29394
BRANCH=none
TEST=manually test LP0 with lid switch quickly and make sure the last
write to restore register successfully

Original-Change-Id: Ifb99ed239eb5572351b8d896535a7c451c17b8f8
Original-Signed-off-by: Joseph Lo <josephl@nvidia.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/205901
Original-Reviewed-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-by: Jimmy Zhang <jimmzhang@nvidia.com>
Original-Commit-Queue: Jimmy Zhang <jimmzhang@nvidia.com>
(cherry picked from commit 4194a9af3999da4b061584cda9649944ec0fdfb1)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: If21d17dc888b2c289970163e4f695423173ca03d
Reviewed-on: http://review.coreboot.org/8151
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
Tested-by: build bot (Jenkins)

1 files changed, 14 insertions, 13 deletions

diff --git a/src/soc/nvidia/tegra124/lp0/tegra_lp0_resume.c b/src/soc/nvidia/tegra124/lp0/tegra_lp0_resume.c
index 0b519d6794..9b1a4b5562 100644
--- a/src/soc/nvidia/tegra124/lp0/tegra_lp0_resume.c
+++ b/src/soc/nvidia/tegra124/lp0/tegra_lp0_resume.c
@@ -419,6 +419,13 @@ static void config_tsc(void)
 	setbits32(TSC_CNTCR_ENABLE | TSC_CNTCR_HDBG, sysctr_cntcr_ptr);
 }
 
+static void enable_cpu_clocks(void)
+{
+	// Enable the CPU complex clock.
+	write32(CLK_ENB_CPU, clk_rst_clk_enb_l_set_ptr);
+	write32(CLK_ENB_CPUG | CLK_ENB_CPULP, clk_rst_clk_enb_v_set_ptr);
+}
+
 
 
 /* Function unit configuration. */
@@ -505,15 +512,15 @@ static void power_on_main_cpu(void)
 	 * Note that PMC_CPUPWRGOOD_TIMER is running at pclk.
 	 *
 	 * We need to reprogram PMC_CPUPWRGOOD_TIMER based on the current pclk
-	 * which is at 408Mhz (pclk = sclk = pllp_out0) after reset. Multiply
-	 * PMC_CPUPWRGOOD_TIMER by 408M / 32K.
+	 * which is at 204Mhz (pclk = sclk = pllp_out2) after BootROM. Multiply
+	 * PMC_CPUPWRGOOD_TIMER by 204M / 32K.
 	 *
 	 * Save the original PMC_CPUPWRGOOD_TIMER register which we need to
 	 * restore after the CPU is powered up.
 	 */
 	uint32_t orig_timer = read32(pmc_ctlr_cpupwrgood_timer_ptr);
 
-	write32(orig_timer * (408000000 / 32768),
+	write32(orig_timer * (204000000 / 32768),
 		pmc_ctlr_cpupwrgood_timer_ptr);
 
 	if (wakeup_on_lp()) {
@@ -525,10 +532,6 @@ static void power_on_main_cpu(void)
 		power_on_partition(PARTID_CE0);
 	}
 
-	// Give I/O signals time to stablize.
-	write32(20 | EVENT_MSEC | FLOW_MODE_STOP,
-		flow_ctlr_halt_cop_events_ptr);
-
 	// Restore the original PMC_CPUPWRGOOD_TIMER.
 	write32(orig_timer, pmc_ctlr_cpupwrgood_timer_ptr);
 }
@@ -575,12 +578,6 @@ void lp0_resume(void)
 	ack_width |= 408 << CAR2PMC_CPU_ACK_WIDTH_SHIFT;
 	write32(ack_width, clk_rst_cpu_softrst_ctrl2_ptr);
 
-	// Enable the CPU complex clock.
-	write32(CLK_ENB_CPU, clk_rst_clk_enb_l_set_ptr);
-	write32(CLK_ENB_CPUG | CLK_ENB_CPULP, clk_rst_clk_enb_v_set_ptr);
-
-	clear_cpu_resets();
-
 	config_tsc();
 
 	// Disable VPR.
@@ -588,8 +585,12 @@ void lp0_resume(void)
 	write32(VIDEO_PROTECT_WRITE_ACCESS_DISABLE,
 		mc_video_protect_reg_ctrl_ptr);
 
+	enable_cpu_clocks();
+
 	power_on_main_cpu();
 
+	clear_cpu_resets();
+
 	// Halt the AVP.
 	while (1)
 		write32(FLOW_MODE_STOP | EVENT_JTAG,