[coreboot-gerrit] New patch to review for coreboot: 0e63e0c tegra124: fix and fine tune the warm boot code

[Marc Jones]

Marc Jones ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/8151

-gerrit

commit 0e63e0c8faa8603212776ae6e4ed7be6e2ad55ec
Author: Joseph Lo 
Date:   Fri Jun 27 11:22:41 2014 +0800

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 
    Original-Reviewed-on: https://chromium-review.googlesource.com/205901
    Original-Reviewed-by: Julius Werner 
    Original-Reviewed-by: Jimmy Zhang 
    Original-Commit-Queue: Jimmy Zhang 
    (cherry picked from commit 4194a9af3999da4b061584cda9649944ec0fdfb1)
    Signed-off-by: Marc Jones

Change-Id: If21d17dc888b2c289970163e4f695423173ca03d
---
 src/soc/nvidia/tegra124/lp0/tegra_lp0_resume.c | 27 +++++++++++++-------------
 1 file 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 0b519d6..9b1a4b5 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,