Skylake: remove the out-dated VR config and un-needed 24mhz calibration

On Skylake, mailbox interface is used to configure VRs, dropping direct msr
writing. With current fsp, svid/vr programming seems to be functional - no
errors are given in the svid transactions in boot, and hw engineer verified
the VRs on Kunimitsu. Additional tunnings might be needed later with power
testing.
24mhz calibration is no longer needed on Skylake due to bclk archtecture
change.

BRANCH=none
BUG=chrome-os-partner:45387
TEST=Built and boot on kunimitsu/glados, reboot, S3/resume verified.
Signed-off-by: robbie zhang <robbie.zhang@intel.com>

Original-Change-Id: If99b5758fcdba8604139c761a07403d4a5d2eb4c
Original-Reviewed-on: https://chromium-review.googlesource.com/301470
Original-Commit-Ready: Robbie Zhang <robbie.zhang@intel.com>
Original-Tested-by: Robbie Zhang <robbie.zhang@intel.com>
Original-Tested-by: Wenkai Du <wenkai.du@intel.com>
Original-Reviewed-by: Duncan Laurie <dlaurie@chromium.org>

Change-Id: I98acf78aac9c705614fb200f8c3313a89296fbf2
Signed-off-by: robbie zhang <robbie.zhang@intel.com>
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/11811
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>

2 files changed, 0 insertions, 121 deletions

diff --git a/src/soc/intel/skylake/cpu.c b/src/soc/intel/skylake/cpu.c
index 1f26093794..0cc9bcaeed 100644
--- a/src/soc/intel/skylake/cpu.c
+++ b/src/soc/intel/skylake/cpu.c
@@ -102,118 +102,6 @@ static const u8 power_limit_time_msr_to_sec[] = {
 	[0x11] = 128,
 };
 
-/*
- * The core 100MHz BLCK is disabled in deeper c-states. One needs to calibrate
- * the 100MHz BCLCK against the 24MHz BLCK to restore the clocks properly
- * when a core is woken up.
- */
-static int pcode_ready(void)
-{
-	int wait_count;
-	const int delay_step = 10;
-
-	wait_count = 0;
-	do {
-		if (!(MCHBAR32(BIOS_MAILBOX_INTERFACE) & MAILBOX_RUN_BUSY))
-			return 0;
-		wait_count += delay_step;
-		udelay(delay_step);
-	} while (wait_count < 1000);
-
-	return -1;
-}
-
-static void calibrate_24mhz_bclk(void)
-{
-	int err_code;
-
-	if (pcode_ready() < 0) {
-		printk(BIOS_ERR, "PCODE: mailbox timeout on wait ready.\n");
-		return;
-	}
-
-	/* A non-zero value initiates the PCODE calibration. */
-	MCHBAR32(BIOS_MAILBOX_DATA) = ~0;
-	MCHBAR32(BIOS_MAILBOX_INTERFACE) =
-		MAILBOX_RUN_BUSY | MAILBOX_BIOS_CMD_FSM_MEASURE_INTVL;
-
-	if (pcode_ready() < 0) {
-		printk(BIOS_ERR, "PCODE: mailbox timeout on completion.\n");
-		return;
-	}
-
-	err_code = MCHBAR32(BIOS_MAILBOX_INTERFACE) & 0xff;
-
-	printk(BIOS_DEBUG, "PCODE: 24MHz BLCK calibration response: %d\n",
-	       err_code);
-
-	/* Read the calibrated value. */
-	MCHBAR32(BIOS_MAILBOX_INTERFACE) =
-		MAILBOX_RUN_BUSY | MAILBOX_BIOS_CMD_READ_CALIBRATION;
-
-	if (pcode_ready() < 0) {
-		printk(BIOS_ERR, "PCODE: mailbox timeout on read.\n");
-		return;
-	}
-
-	printk(BIOS_DEBUG, "PCODE: 24MHz BLCK calibration value: 0x%08x\n",
-	       MCHBAR32(BIOS_MAILBOX_DATA));
-}
-
-static void initialize_vr_config(void)
-{
-	msr_t msr;
-
-	printk(BIOS_DEBUG, "Initializing VR config.\n");
-
-	/*  Configure VR_CURRENT_CONFIG. */
-	msr = rdmsr(MSR_VR_CURRENT_CONFIG);
-	/*
-	 * Preserve bits 63 and 62. Bit 62 is PSI4 enable, but it is only valid
-	 * on ULT systems.
-	 */
-	msr.hi &= 0xc0000000;
-	msr.hi |= (0x01 << (52 - 32)); /* PSI3 threshold -  1A. */
-	msr.hi |= (0x05 << (42 - 32)); /* PSI2 threshold -  5A. */
-	msr.hi |= (0x14 << (32 - 32)); /* PSI1 threshold - 20A. */
-	msr.hi |= (1 <<  (62 - 32)); /* Enable PSI4 */
-	/* Leave the max instantaneous current limit (12:0) to default. */
-	wrmsr(MSR_VR_CURRENT_CONFIG, msr);
-
-	/*  Configure VR_MISC_CONFIG MSR. */
-	msr = rdmsr(MSR_VR_MISC_CONFIG);
-	/* Set the IOUT_SLOPE scalar applied to dIout in U10.1.9 format. */
-	msr.hi &= ~(0x3ff << (40 - 32));
-	msr.hi |= (0x200 << (40 - 32)); /* 1.0 */
-	/* Set IOUT_OFFSET to 0. */
-	msr.hi &= ~0xff;
-	/* Set exit ramp rate to fast. */
-	msr.hi |= (1 << (50 - 32));
-	/* Set entry ramp rate to slow. */
-	msr.hi &= ~(1 << (51 - 32));
-	/* Enable decay mode on C-state entry. */
-	msr.hi |= (1 << (52 - 32));
-	/* Set the slow ramp rate to be fast ramp rate / 4 */
-	msr.hi &= ~(0x3 << (53 - 32));
-	msr.hi |= (0x01 << (53 - 32));
-	/* Set MIN_VID (31:24) to allow CPU to have full control. */
-	msr.lo &= ~0xff000000;
-	wrmsr(MSR_VR_MISC_CONFIG, msr);
-
-	/*  Configure VR_MISC_CONFIG2 MSR. */
-	msr = rdmsr(MSR_VR_MISC_CONFIG2);
-	msr.lo &= ~0xffff;
-	/*
-	 * Allow CPU to control minimum voltage completely (15:8) and
-	 * set the fast ramp voltage in 10mV steps.
-	 */
-	if (cpu_family_model() == SKYLAKE_FAMILY_ULT)
-		msr.lo |= 0x006a; /* 1.56V */
-	else
-		msr.lo |= 0x006f; /* 1.60V */
-	wrmsr(MSR_VR_MISC_CONFIG2, msr);
-}
-
 int cpu_config_tdp_levels(void)
 {
 	msr_t platform_info;
@@ -427,9 +315,6 @@ static void bsp_init_before_ap_bringup(struct bus *cpu_bus)
 	x86_setup_fixed_mtrrs();
 	x86_setup_var_mtrrs(cpuid_eax(0x80000008) & 0xff, 2);
 	x86_mtrr_check();
-
-	initialize_vr_config();
-	calibrate_24mhz_bclk();
 }
 
 /* All CPUs including BSP will run the following function. */
diff --git a/src/soc/intel/skylake/include/soc/systemagent.h b/src/soc/intel/skylake/include/soc/systemagent.h
index 59221c7754..19d752822f 100644
--- a/src/soc/intel/skylake/include/soc/systemagent.h
+++ b/src/soc/intel/skylake/include/soc/systemagent.h
@@ -102,12 +102,6 @@
 /* PCODE MMIO communications live in the MCHBAR. */
 #define BIOS_MAILBOX_INTERFACE			0x5da4
 #define  MAILBOX_RUN_BUSY			(1 << 31)
-#define  MAILBOX_BIOS_CMD_READ_PCS		1
-#define  MAILBOX_BIOS_CMD_WRITE_PCS		2
-#define  MAILBOX_BIOS_CMD_READ_CALIBRATION	0x509
-#define  MAILBOX_BIOS_CMD_FSM_MEASURE_INTVL	0x909
-#define  MAILBOX_BIOS_CMD_READ_PCH_POWER	0xa
-#define  MAILBOX_BIOS_CMD_READ_PCH_POWER_EXT	0xb
 /* Errors are returned back in bits 7:0. */
 #define  MAILBOX_BIOS_ERROR_NONE		0
 #define  MAILBOX_BIOS_ERROR_INVALID_COMMAND	1