[PATCH 11/12] cpufreq: mediatek: add opp notification for SVS support

Andrew-sh.Cheng
2020-05-20T03:52:19Z

cpufreq should listen opp notification and do proper actions
when receiving disable and voltage adjustment events,
which are triggered when SVS is enabled.

Signed-off-by: Andrew-sh.Cheng <andrew-sh.cheng@mediatek.com>
---
drivers/cpufreq/mediatek-cpufreq.c | 89 ++++++++++++++++++++++++++++++++++++--
1 file changed, 85 insertions(+), 4 deletions(-)

diff --git a/drivers/cpufreq/mediatek-cpufreq.c b/drivers/cpufreq/mediatek-cpufreq.c
index 4b479c110cc9..71395ab87ac7 100644
--- a/drivers/cpufreq/mediatek-cpufreq.c
+++ b/drivers/cpufreq/mediatek-cpufreq.c
@@ -42,6 +42,11 @@ struct mtk_cpu_dvfs_info {
struct list_head list_head;
int intermediate_voltage;
bool need_voltage_tracking;
+ struct mutex lock; /* avoid notify and policy race condition */
+ struct notifier_block opp_nb;
+ int opp_cpu;
+ unsigned long opp_freq;
+ int old_vproc;
};

static LIST_HEAD(dvfs_info_list);
@@ -192,11 +197,16 @@ static int mtk_cpufreq_voltage_tracking(struct mtk_cpu_dvfs_info *info,

static int mtk_cpufreq_set_voltage(struct mtk_cpu_dvfs_info *info, int vproc)
{
+ int ret;
+
if (info->need_voltage_tracking)
- return mtk_cpufreq_voltage_tracking(info, vproc);
+ ret = mtk_cpufreq_voltage_tracking(info, vproc);
else
- return regulator_set_voltage(info->proc_reg, vproc,
- vproc + VOLT_TOL);
+ ret = regulator_set_voltage(info->proc_reg, vproc,
+ MAX_VOLT_LIMIT);
+ if (!ret)
+ info->old_vproc = vproc;
+ return ret;
}

static int mtk_cpufreq_set_target(struct cpufreq_policy *policy,
@@ -214,7 +224,9 @@ static int mtk_cpufreq_set_target(struct cpufreq_policy *policy,
inter_vproc = info->intermediate_voltage;

old_freq_hz = clk_get_rate(cpu_clk);
- old_vproc = regulator_get_voltage(info->proc_reg);
+ old_vproc = info->old_vproc;
+ if (old_vproc == 0)
+ old_vproc = regulator_get_voltage(info->proc_reg);
if (old_vproc < 0) {
pr_err("%s: invalid Vproc value: %d\n", __func__, old_vproc);
return old_vproc;
@@ -231,6 +243,7 @@ static int mtk_cpufreq_set_target(struct cpufreq_policy *policy,
vproc = dev_pm_opp_get_voltage(opp);
dev_pm_opp_put(opp);

+ mutex_lock(&info->lock);
/*
* If the new voltage or the intermediate voltage is higher than the
* current voltage, scale up voltage first.
@@ -242,6 +255,7 @@ static int mtk_cpufreq_set_target(struct cpufreq_policy *policy,
pr_err("cpu%d: failed to scale up voltage!\n",
policy->cpu);
mtk_cpufreq_set_voltage(info, old_vproc);
+ mutex_unlock(&info->lock);
return ret;
}
}
@@ -253,6 +267,7 @@ static int mtk_cpufreq_set_target(struct cpufreq_policy *policy,
policy->cpu);
mtk_cpufreq_set_voltage(info, old_vproc);
WARN_ON(1);
+ mutex_unlock(&info->lock);
return ret;
}

@@ -263,6 +278,7 @@ static int mtk_cpufreq_set_target(struct cpufreq_policy *policy,
policy->cpu);
clk_set_parent(cpu_clk, armpll);
mtk_cpufreq_set_voltage(info, old_vproc);
+ mutex_unlock(&info->lock);
return ret;
}

@@ -273,6 +289,7 @@ static int mtk_cpufreq_set_target(struct cpufreq_policy *policy,
policy->cpu);
mtk_cpufreq_set_voltage(info, inter_vproc);
WARN_ON(1);
+ mutex_unlock(&info->lock);
return ret;
}

@@ -288,15 +305,69 @@ static int mtk_cpufreq_set_target(struct cpufreq_policy *policy,
clk_set_parent(cpu_clk, info->inter_clk);
clk_set_rate(armpll, old_freq_hz);
clk_set_parent(cpu_clk, armpll);
+ mutex_unlock(&info->lock);
return ret;
}
}

+ info->opp_freq = freq_hz;
+ mutex_unlock(&info->lock);
+
return 0;
}

#define DYNAMIC_POWER "dynamic-power-coefficient"

+static int mtk_cpufreq_opp_notifier(struct notifier_block *nb,
+ unsigned long event, void *data)
+{
+ struct dev_pm_opp *opp = data;
+ struct dev_pm_opp *new_opp;
+ struct mtk_cpu_dvfs_info *info;
+ unsigned long freq, volt;
+ struct cpufreq_policy *policy;
+ int ret = 0;
+
+ info = container_of(nb, struct mtk_cpu_dvfs_info, opp_nb);
+
+ if (event == OPP_EVENT_ADJUST_VOLTAGE) {
+ freq = dev_pm_opp_get_freq(opp);
+
+ mutex_lock(&info->lock);
+ if (info->opp_freq == freq) {
+ volt = dev_pm_opp_get_voltage(opp);
+ ret = mtk_cpufreq_set_voltage(info, volt);
+ if (ret)
+ dev_err(info->cpu_dev, "failed to scale voltage: %d\n",
+ ret);
+ }
+ mutex_unlock(&info->lock);
+ } else if (event == OPP_EVENT_DISABLE) {
+ freq = dev_pm_opp_get_freq(opp);
+ /* case of current opp item is disabled */
+ if (info->opp_freq == freq) {
+ freq = 1;
+ new_opp = dev_pm_opp_find_freq_ceil(info->cpu_dev,
+ &freq);
+ if (!IS_ERR(new_opp)) {
+ dev_pm_opp_put(new_opp);
+ policy = cpufreq_cpu_get(info->opp_cpu);
+ if (policy) {
+ cpufreq_driver_target(policy,
+ freq / 1000,
+ CPUFREQ_RELATION_L);
+ cpufreq_cpu_put(policy);
+ }
+ } else {
+ pr_err("%s: all opp items are disabled\n",
+ __func__);
+ }
+ }
+ }
+
+ return notifier_from_errno(ret);
+}
+
static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu)
{
struct device *cpu_dev;
@@ -392,11 +463,21 @@ static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu)
info->intermediate_voltage = dev_pm_opp_get_voltage(opp);
dev_pm_opp_put(opp);

+ info->opp_cpu = cpu;
+ info->opp_nb.notifier_call = mtk_cpufreq_opp_notifier;
+ ret = dev_pm_opp_register_notifier(cpu_dev, &info->opp_nb);
+ if (ret) {
+ pr_warn("cannot register opp notification\n");
+ goto out_disable_inter_clock;
+ }
+
+ mutex_init(&info->lock);
info->cpu_dev = cpu_dev;
info->proc_reg = proc_reg;
info->sram_reg = IS_ERR(sram_reg) ? NULL : sram_reg;
info->cpu_clk = cpu_clk;
info->inter_clk = inter_clk;
+ info->opp_freq = clk_get_rate(cpu_clk);

/*
* If SRAM regulator is present, software "voltage tracking" is needed
--
2.12.5