cpufreq: amd-pstate: Add resume and suspend callbacks

When system resumes from S3, the CPPC enable register will be
cleared and reset to 0.

So enable the CPPC interface by writing 1 to this register on
system resume and disable it during system suspend.

Signed-off-by: Jinzhou Su <Jinzhou.Su@amd.com>
Signed-off-by: Jinzhou Su <Jinzhou.Su@amd.com>
Acked-by: Huang Rui <ray.huang@amd.com>
[ rjw: Subject and changelog edits ]
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 7be38bc6a673b09c90d578413b38c731a135dc84..9ac75c1cde9c22fc3bcee6885521477ea1352625 100644 (file)
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -566,6 +566,28 @@ static int amd_pstate_cpu_exit(struct cpufreq_policy *policy)
        return 0;
 }
 
+static int amd_pstate_cpu_resume(struct cpufreq_policy *policy)
+{
+       int ret;
+
+       ret = amd_pstate_enable(true);
+       if (ret)
+               pr_err("failed to enable amd-pstate during resume, return %d\n", ret);
+
+       return ret;
+}
+
+static int amd_pstate_cpu_suspend(struct cpufreq_policy *policy)
+{
+       int ret;
+
+       ret = amd_pstate_enable(false);
+       if (ret)
+               pr_err("failed to disable amd-pstate during suspend, return %d\n", ret);
+
+       return ret;
+}
+
 /* Sysfs attributes */
 
 /*
@@ -636,6 +658,8 @@ static struct cpufreq_driver amd_pstate_driver = {
        .target         = amd_pstate_target,
        .init           = amd_pstate_cpu_init,
        .exit           = amd_pstate_cpu_exit,
+       .suspend        = amd_pstate_cpu_suspend,
+       .resume         = amd_pstate_cpu_resume,
        .set_boost      = amd_pstate_set_boost,
        .name           = "amd-pstate",
        .attr           = amd_pstate_attr,