intel_pstate: Add support for Baytrail turbo P states

A documentation update exposed the existance of the turbo ratio
register. Update baytrail support to use the turbo range.
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Cc: 3.13+ <stable@vger.kernel.org> # 3.13+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/intel_pstate.c

@@ -36,6 +36,8 @@
 
 #define BYT_RATIOS		0x66a
 #define BYT_VIDS		0x66b
+#define BYT_TURBO_RATIOS	0x66c
+
 
 #define FRAC_BITS 8
 #define int_tofp(X) ((int64_t)(X) << FRAC_BITS)
@@ -367,6 +369,13 @@ static int byt_get_max_pstate(void)
 	return (value >> 16) & 0xFF;
 }
 
+static int byt_get_turbo_pstate(void)
+{
+	u64 value;
+	rdmsrl(BYT_TURBO_RATIOS, value);
+	return value & 0x3F;
+}
+
 static void byt_set_pstate(struct cpudata *cpudata, int pstate)
 {
 	u64 val;
@@ -469,7 +478,7 @@ static struct cpu_defaults byt_params = {
 	.funcs = {
 		.get_max = byt_get_max_pstate,
 		.get_min = byt_get_min_pstate,
-		.get_turbo = byt_get_max_pstate,
+		.get_turbo = byt_get_turbo_pstate,
 		.set = byt_set_pstate,
 		.get_vid = byt_get_vid,
 	},