intel_pstate: Add Baytrail support

Add support for the Baytrail processor.

Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 35 insertions, 0 deletions

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 6b37c9ff1d64..27c2753909fe 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -33,6 +33,8 @@
 
 #define SAMPLE_COUNT            3
 
+#define BYT_RATIOS      0x66a
+
 #define FRAC_BITS 8
 #define int_tofp(X) ((int64_t)(X) << FRAC_BITS)
 #define fp_toint(X) ((X) >> FRAC_BITS)
@@ -342,6 +344,20 @@ static void intel_pstate_sysfs_expose_params(void)
 }
 
 /************************** sysfs end ************************/
+static int byt_get_min_pstate(void)
+{
+        u64 value;
+        rdmsrl(BYT_RATIOS, value);
+        return value & 0xFF;
+}
+
+static int byt_get_max_pstate(void)
+{
+        u64 value;
+        rdmsrl(BYT_RATIOS, value);
+        return (value >> 16) & 0xFF;
+}
+
 static int core_get_min_pstate(void)
 {
         u64 value;
@@ -396,6 +412,24 @@ static struct cpu_defaults core_params = {
         },
 };
 
+static struct cpu_defaults byt_params = {
+        .pid_policy = {
+                .sample_rate_ms = 10,
+                .deadband = 0,
+                .setpoint = 97,
+                .p_gain_pct = 14,
+                .d_gain_pct = 0,
+                .i_gain_pct = 4,
+        },
+        .funcs = {
+                .get_max = byt_get_max_pstate,
+                .get_min = byt_get_min_pstate,
+                .get_turbo = byt_get_max_pstate,
+                .set = core_set_pstate,
+        },
+};
+
+
 static void intel_pstate_get_min_max(struct cpudata *cpu, int *min, int *max)
 {
         int max_perf = cpu->pstate.turbo_pstate;
@@ -553,6 +587,7 @@ static void intel_pstate_timer_func(unsigned long __data)
 static const struct x86_cpu_id intel_pstate_cpu_ids[] = {
         ICPU(0x2a, core_params),
         ICPU(0x2d, core_params),
+        ICPU(0x37, byt_params),
         ICPU(0x3a, core_params),
         ICPU(0x3c, core_params),
         ICPU(0x3e, core_params),