diff mbox series

[V3,05/15] cpufreq: mediatek: Add opp notification support

Message ID 20220415055916.28350-6-rex-bc.chen@mediatek.com (mailing list archive)
State New, archived
Headers show
Series cpufreq: mediatek: Cleanup and support MT8183 and MT8186 | expand

Commit Message

Rex-BC Chen (陳柏辰) April 15, 2022, 5:59 a.m. UTC
From: "Andrew-sh.Cheng" <andrew-sh.cheng@mediatek.com>

From this opp notifier, cpufreq should listen to opp notification and do
proper actions when receiving events of disable and voltage adjustment.

One of the user for this opp notifier is MediaTek SVS.
The MediaTek Smart Voltage Scaling (SVS) is a hardware which calculates
suitable SVS bank voltages to OPP voltage table.

Signed-off-by: Andrew-sh.Cheng <andrew-sh.cheng@mediatek.com>
Signed-off-by: Jia-Wei Chang <jia-wei.chang@mediatek.com>
Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
---
 drivers/cpufreq/mediatek-cpufreq.c | 93 +++++++++++++++++++++++++++---
 1 file changed, 85 insertions(+), 8 deletions(-)

Comments

AngeloGioacchino Del Regno April 15, 2022, 12:24 p.m. UTC | #1
Il 15/04/22 07:59, Rex-BC Chen ha scritto:
> From: "Andrew-sh.Cheng" <andrew-sh.cheng@mediatek.com>
> 
>  From this opp notifier, cpufreq should listen to opp notification and do
> proper actions when receiving events of disable and voltage adjustment.
> 
> One of the user for this opp notifier is MediaTek SVS.
> The MediaTek Smart Voltage Scaling (SVS) is a hardware which calculates
> suitable SVS bank voltages to OPP voltage table.
> 
> Signed-off-by: Andrew-sh.Cheng <andrew-sh.cheng@mediatek.com>
> Signed-off-by: Jia-Wei Chang <jia-wei.chang@mediatek.com>
> Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
> ---
>   drivers/cpufreq/mediatek-cpufreq.c | 93 +++++++++++++++++++++++++++---
>   1 file changed, 85 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/cpufreq/mediatek-cpufreq.c b/drivers/cpufreq/mediatek-cpufreq.c
> index fa8b193bf27b..221f249f8d21 100644
> --- a/drivers/cpufreq/mediatek-cpufreq.c
> +++ b/drivers/cpufreq/mediatek-cpufreq.c
> @@ -41,6 +41,11 @@ struct mtk_cpu_dvfs_info {
>   	int intermediate_voltage;
>   	bool need_voltage_tracking;
>   	int pre_vproc;
> +	/* Avoid race condition for regulators between notify and policy */
> +	struct mutex reg_lock;
> +	struct notifier_block opp_nb;
> +	int opp_cpu;

This should be unsigned int because:
1. A negative CPU number is impossible;
2. The only usage is as a parameter of cpufreq_cpu_get(unsigned int cpu).

Please change this to unsigned int, after which:

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Rex-BC Chen (陳柏辰) April 18, 2022, 1:38 a.m. UTC | #2
On Fri, 2022-04-15 at 14:24 +0200, AngeloGioacchino Del Regno wrote:
> Il 15/04/22 07:59, Rex-BC Chen ha scritto:
> > From: "Andrew-sh.Cheng" <andrew-sh.cheng@mediatek.com>
> > 
> >  From this opp notifier, cpufreq should listen to opp notification
> > and do
> > proper actions when receiving events of disable and voltage
> > adjustment.
> > 
> > One of the user for this opp notifier is MediaTek SVS.
> > The MediaTek Smart Voltage Scaling (SVS) is a hardware which
> > calculates
> > suitable SVS bank voltages to OPP voltage table.
> > 
> > Signed-off-by: Andrew-sh.Cheng <andrew-sh.cheng@mediatek.com>
> > Signed-off-by: Jia-Wei Chang <jia-wei.chang@mediatek.com>
> > Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
> > ---
> >   drivers/cpufreq/mediatek-cpufreq.c | 93
> > +++++++++++++++++++++++++++---
> >   1 file changed, 85 insertions(+), 8 deletions(-)
> > 
> > diff --git a/drivers/cpufreq/mediatek-cpufreq.c
> > b/drivers/cpufreq/mediatek-cpufreq.c
> > index fa8b193bf27b..221f249f8d21 100644
> > --- a/drivers/cpufreq/mediatek-cpufreq.c
> > +++ b/drivers/cpufreq/mediatek-cpufreq.c
> > @@ -41,6 +41,11 @@ struct mtk_cpu_dvfs_info {
> >   	int intermediate_voltage;
> >   	bool need_voltage_tracking;
> >   	int pre_vproc;
> > +	/* Avoid race condition for regulators between notify and
> > policy */
> > +	struct mutex reg_lock;
> > +	struct notifier_block opp_nb;
> > +	int opp_cpu;
> 
> This should be unsigned int because:
> 1. A negative CPU number is impossible;
> 2. The only usage is as a parameter of cpufreq_cpu_get(unsigned int
> cpu).
> 
> Please change this to unsigned int, after which:
> 
> Reviewed-by: AngeloGioacchino Del Regno <
> angelogioacchino.delregno@collabora.com>
> 

Hello Angelo, 

OK, I will do this in next version.
Thanks!

BRs,
Rex
diff mbox series

Patch

diff --git a/drivers/cpufreq/mediatek-cpufreq.c b/drivers/cpufreq/mediatek-cpufreq.c
index fa8b193bf27b..221f249f8d21 100644
--- a/drivers/cpufreq/mediatek-cpufreq.c
+++ b/drivers/cpufreq/mediatek-cpufreq.c
@@ -41,6 +41,11 @@  struct mtk_cpu_dvfs_info {
 	int intermediate_voltage;
 	bool need_voltage_tracking;
 	int pre_vproc;
+	/* Avoid race condition for regulators between notify and policy */
+	struct mutex reg_lock;
+	struct notifier_block opp_nb;
+	int opp_cpu;
+	unsigned long opp_freq;
 };
 
 static LIST_HEAD(dvfs_info_list);
@@ -220,6 +225,9 @@  static int mtk_cpufreq_set_target(struct cpufreq_policy *policy,
 	inter_vproc = info->intermediate_voltage;
 
 	pre_freq_hz = clk_get_rate(cpu_clk);
+
+	mutex_lock(&info->reg_lock);
+
 	pre_vproc = info->pre_vproc;
 	if (pre_vproc <= 0)
 		pre_vproc = regulator_get_voltage(info->proc_reg);
@@ -250,7 +258,7 @@  static int mtk_cpufreq_set_target(struct cpufreq_policy *policy,
 			dev_err(cpu_dev,
 				"cpu%d: failed to scale up voltage!\n", policy->cpu);
 			mtk_cpufreq_set_voltage(info, pre_vproc);
-			return ret;
+			goto out;
 		}
 	}
 
@@ -260,8 +268,7 @@  static int mtk_cpufreq_set_target(struct cpufreq_policy *policy,
 		dev_err(cpu_dev,
 			"cpu%d: failed to re-parent cpu clock!\n", policy->cpu);
 		mtk_cpufreq_set_voltage(info, pre_vproc);
-		WARN_ON(1);
-		return ret;
+		goto out;
 	}
 
 	/* Set the original PLL to target rate. */
@@ -271,7 +278,7 @@  static int mtk_cpufreq_set_target(struct cpufreq_policy *policy,
 			"cpu%d: failed to scale cpu clock rate!\n", policy->cpu);
 		clk_set_parent(cpu_clk, armpll);
 		mtk_cpufreq_set_voltage(info, pre_vproc);
-		return ret;
+		goto out;
 	}
 
 	/* Set parent of CPU clock back to the original PLL. */
@@ -280,8 +287,7 @@  static int mtk_cpufreq_set_target(struct cpufreq_policy *policy,
 		dev_err(cpu_dev,
 			"cpu%d: failed to re-parent cpu clock!\n", policy->cpu);
 		mtk_cpufreq_set_voltage(info, inter_vproc);
-		WARN_ON(1);
-		return ret;
+		goto out;
 	}
 
 	/*
@@ -296,15 +302,72 @@  static int mtk_cpufreq_set_target(struct cpufreq_policy *policy,
 			clk_set_parent(cpu_clk, info->inter_clk);
 			clk_set_rate(armpll, pre_freq_hz);
 			clk_set_parent(cpu_clk, armpll);
-			return ret;
+			goto out;
 		}
 	}
 
-	return 0;
+	info->opp_freq = freq_hz;
+
+out:
+	mutex_unlock(&info->reg_lock);
+
+	return ret;
 }
 
 #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->reg_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->reg_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_err(info->cpu_dev,
+					"all opp items are disabled\n");
+				ret = PTR_ERR(new_opp);
+				return notifier_from_errno(ret);
+			}
+
+			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);
+			}
+		}
+	}
+
+	return notifier_from_errno(ret);
+}
+
 static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu)
 {
 	struct device *cpu_dev;
@@ -393,6 +456,17 @@  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) {
+		dev_err(cpu_dev, "cpu%d: failed to register opp notifier\n", cpu);
+		goto out_disable_inter_clock;
+	}
+
+	mutex_init(&info->reg_lock);
+	info->opp_freq = clk_get_rate(info->cpu_clk);
+
 	/*
 	 * If SRAM regulator is present, software "voltage tracking" is needed
 	 * for this CPU power domain.
@@ -448,6 +522,9 @@  static void mtk_cpu_dvfs_info_release(struct mtk_cpu_dvfs_info *info)
 	}
 
 	dev_pm_opp_of_cpumask_remove_table(&info->cpus);
+
+	if (!IS_ERR_OR_NULL(info->cpu_dev))
+		dev_pm_opp_unregister_notifier(info->cpu_dev, &info->opp_nb);
 }
 
 static int mtk_cpufreq_init(struct cpufreq_policy *policy)