From b376471fb47d4905e72fe73e9eeed228f8f2f230 Mon Sep 17 00:00:00 2001
From: Jinzhou Su <Jinzhou.Su@amd.com>
Date: Thu, 23 Jun 2022 11:15:09 +0800
Subject: [PATCH] cpufreq: amd-pstate: Add resume and suspend callbacks
Git-commit: b376471fb47d4905e72fe73e9eeed228f8f2f230
Patch-mainline: v5.19-rc5
References: bsc#1212445

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>
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>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/cpufreq/amd-pstate.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 7be38bc6a673..9ac75c1cde9c 100644
--- 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,
-- 
2.35.3