cpu/intel/haswell: Add fast ramp voltage for Broadwell

Backport commit 55228ba4b4 (broadwell: Changes from 2.2.0 ref code) to
Haswell, to eventually migrate Broadwell to use the same Haswell code.

Change-Id: I03d9ff16bcaab9091bd723ce933aa3f2d71e29b9
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/46921
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/cpu/intel/haswell/haswell.h

@@ -3,6 +3,7 @@
 #ifndef _CPU_INTEL_HASWELL_H
 #define _CPU_INTEL_HASWELL_H
 
+#include <arch/cpu.h>
 #include <stdint.h>
 
 /* CPU types without stepping */
@@ -168,6 +169,11 @@ void set_power_limits(u8 power_limit_1_time);
 int cpu_config_tdp_levels(void);
 
 /* CPU identification */
+static inline u32 cpu_family_model(void)
+{
+	return cpuid_eax(1) & 0x0fff0ff0;
+}
+
 static inline int haswell_is_ult(void)
 {
 	return CONFIG(INTEL_LYNXPOINT_LP);

src/cpu/intel/haswell/haswell_init.c

@@ -294,8 +294,11 @@ static void initialize_vr_config(void)
 	msr = rdmsr(MSR_VR_MISC_CONFIG2);
 	msr.lo &= ~0xffff;
 	/* Allow CPU to control minimum voltage completely (15:8) and
-	 * set the fast ramp voltage to 1110mV (0x6f in 10mV steps). */
-	msr.lo |= 0x006f;
+	   set the fast ramp voltage in 10mV steps. */
+	if (cpu_family_model() == BROADWELL_FAMILY_ULT)
+		msr.lo |= 0x006a; /* 1.56V */
+	else
+		msr.lo |= 0x006f; /* 1.60V */
 	wrmsr(MSR_VR_MISC_CONFIG2, msr);
 }