[PATCH 1/2] cpufreq: mediatek: Enter system sleep at the suspend OPP

[Ryan Brue]

cpufreq_suspend() stops the governors at the start of system suspend, and
this driver has no .suspend callback, so each cluster sleeps at whatever
OPP it was last left at. On an MT8173 tablet (Amazon Fire HD 10, 2017),
entering suspend-to-RAM with both clusters at their highest OPP measured
63.5 mA. With this change and the lowest OPP marked, the same entry
measured 52.0 mA.

Use the generic suspend-frequency support, as cpufreq-dt does. Tables
without an opp-suspend entry leave suspend_freq at 0, which makes
cpufreq_generic_suspend() a no-op, so they are unaffected.

Assisted-by: LLM
---
 drivers/cpufreq/mediatek-cpufreq.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/cpufreq/mediatek-cpufreq.c b/drivers/cpufreq/mediatek-cpufreq.c
index 052ca7cd2f4f..f9b1eca176eb 100644
--- a/drivers/cpufreq/mediatek-cpufreq.c
+++ b/drivers/cpufreq/mediatek-cpufreq.c
@@ -603,6 +603,7 @@ static int mtk_cpufreq_init(struct cpufreq_policy *policy)
 	policy->freq_table = freq_table;
 	policy->driver_data = info;
 	policy->clk = info->cpu_clk;
+	policy->suspend_freq = dev_pm_opp_get_suspend_opp_freq(info->cpu_dev) / 1000;
 
 	return 0;
 }
@@ -624,6 +625,7 @@ static struct cpufreq_driver mtk_cpufreq_driver = {
 	.init = mtk_cpufreq_init,
 	.exit = mtk_cpufreq_exit,
 	.register_em = cpufreq_register_em_with_opp,
+	.suspend = cpufreq_generic_suspend,
 	.name = "mtk-cpufreq",
 };
 

-- 
2.55.0