[PATCH v3 0/2] PM / Domains: Add support for 'required-opps' to set default perf state

[PATCH v3 0/2] PM / Domains: Add support for 'required-opps' to set default perf state

[Rajendra Nayak]

This is a re-spin of the series [1] which was adding support for a new
DT binding (assigned-performance-state) and based on the discussions on
that thread [2] it was concluded that we could achieve the same with the
existing 'required-opps' binding instead.

So this series, just drops the new binding and uses required-opps to achieve
the default perf state setting thats needed by some devices.

---
Some devics within power-domains with performance states do not
support DVFS, but still need to vote on a default/static state
while they are active. Add support for this using the 'required-opps'
property in device tree.

[1] https://lore.kernel.org/patchwork/project/lkml/list/?series=501336&state=%2A&archive=both
[2] https://lore.kernel.org/patchwork/patch/1436886/

Rajendra Nayak (2):
  PM / Domains: Add support for 'required-opps' to set default perf
    state
  arm64: dts: sc7180: Add required-opps for i2c

 arch/arm64/boot/dts/qcom/sc7180.dtsi | 24 ++++++++++++++++++++++++
 drivers/base/power/domain.c          | 27 +++++++++++++++++++++++++++
 include/linux/pm_domain.h            |  1 +
 3 files changed, 52 insertions(+)

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[PATCH v3 1/2] PM / Domains: Add support for 'required-opps' to set default perf state

[Rajendra Nayak]

Some devics within power domains with performance states do not
support DVFS, but still need to vote on a default/static state
while they are active. They can express this using the 'required-opps'
property in device tree, which points to the phandle of the OPP
supported by the corresponding power-domains.

Add support to parse this information from DT and then set the
specified performance state during attach and drop it on detach.
Also drop/set as part of runtime suspend/resume callbacks.

Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
---
 drivers/base/power/domain.c | 29 ++++++++++++++++++++++++++++-
 include/linux/pm_domain.h   |  1 +
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index a934c67..eef5507 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -917,6 +917,10 @@ static int genpd_runtime_suspend(struct device *dev)
 	if (irq_safe_dev_in_no_sleep_domain(dev, genpd))
 		return 0;
 
+	/* Drop the default performance state */
+	if (dev_gpd_data(dev)->default_pstate)
+		dev_pm_genpd_set_performance_state(dev, 0);
+
 	genpd_lock(genpd);
 	gpd_data->rpm_pstate = genpd_drop_performance_state(dev);
 	genpd_power_off(genpd, true, 0);
@@ -937,6 +941,7 @@ static int genpd_runtime_resume(struct device *dev)
 {
 	struct generic_pm_domain *genpd;
 	struct generic_pm_domain_data *gpd_data = dev_gpd_data(dev);
+	unsigned int default_pstate = gpd_data->default_pstate;
 	struct gpd_timing_data *td = &gpd_data->td;
 	bool runtime_pm = pm_runtime_enabled(dev);
 	ktime_t time_start;
@@ -968,6 +973,9 @@ static int genpd_runtime_resume(struct device *dev)
 	if (ret)
 		return ret;
 
+	/* Set the default performance state */
+	if (default_pstate)
+		dev_pm_genpd_set_performance_state(dev, default_pstate);
  out:
 	/* Measure resume latency. */
 	time_start = 0;
@@ -1000,6 +1008,8 @@ static int genpd_runtime_resume(struct device *dev)
 	genpd_stop_dev(genpd, dev);
 err_poweroff:
 	if (!pm_runtime_is_irq_safe(dev) || genpd_is_irq_safe(genpd)) {
+		if (default_pstate)
+			dev_pm_genpd_set_performance_state(dev, 0);
 		genpd_lock(genpd);
 		gpd_data->rpm_pstate = genpd_drop_performance_state(dev);
 		genpd_power_off(genpd, true, 0);
@@ -2598,6 +2608,12 @@ static void genpd_dev_pm_detach(struct device *dev, bool power_off)
 
 	dev_dbg(dev, "removing from PM domain %s\n", pd->name);
 
+	/* Drop the default performance state */
+	if (dev_gpd_data(dev)->default_pstate) {
+		dev_pm_genpd_set_performance_state(dev, 0);
+		dev_gpd_data(dev)->default_pstate = 0;
+	}
+
 	for (i = 1; i < GENPD_RETRY_MAX_MS; i <<= 1) {
 		ret = genpd_remove_device(pd, dev);
 		if (ret != -EAGAIN)
@@ -2635,9 +2651,10 @@ static void genpd_dev_pm_sync(struct device *dev)
 static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,
 				 unsigned int index, bool power_on)
 {
+	struct device_node *np;
 	struct of_phandle_args pd_args;
 	struct generic_pm_domain *pd;
-	int ret;
+	int ret, pstate;
 
 	ret = of_parse_phandle_with_args(dev->of_node, "power-domains",
 				"#power-domain-cells", index, &pd_args);
@@ -2678,6 +2695,16 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,
 	if (ret)
 		genpd_remove_device(pd, dev);
 
+	/* Set the default performance state */
+	np = base_dev->of_node;
+	if (of_parse_phandle(np, "required-opps", index)) {
+		pstate = of_get_required_opp_performance_state(np, index);
+		if (pstate > 0) {
+			dev_pm_genpd_set_performance_state(dev, pstate);
+			dev_gpd_data(dev)->default_pstate = pstate;
+		}
+	}
+
 	return ret ? -EPROBE_DEFER : 1;
 }
 
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 21a0577..67017c9 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -198,6 +198,7 @@ struct generic_pm_domain_data {
 	struct notifier_block *power_nb;
 	int cpu;
 	unsigned int performance_state;
+	unsigned int default_pstate;
 	unsigned int rpm_pstate;
 	ktime_t	next_wakeup;
 	void *data;
-- 
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of Code Aurora Forum, hosted by The Linux Foundation

[PATCH v3 2/2] arm64: dts: sc7180: Add required-opps for i2c

[Rajendra Nayak]

qup-i2c devices on sc7180 are clocked with a fixed clock (19.2 MHz)
Though qup-i2c does not support DVFS, it still needs to vote for a
performance state on 'CX' to satisfy the 19.2 Mhz clock frequency
requirement.

Use 'required-opps' to pass this information from
device tree, and also add the power-domains property to specify
the CX power-domain.

Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
---
 arch/arm64/boot/dts/qcom/sc7180.dtsi | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/sc7180.dtsi b/arch/arm64/boot/dts/qcom/sc7180.dtsi
index a5d58eb..cd30185 100644
--- a/arch/arm64/boot/dts/qcom/sc7180.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7180.dtsi
@@ -785,8 +785,10 @@
 						<&gem_noc MASTER_APPSS_PROC 0 &config_noc SLAVE_QUP_0 0>,
 						<&aggre1_noc MASTER_QUP_0 0 &mc_virt SLAVE_EBI1 0>;
 				interconnect-names = "qup-core", "qup-config",
 							"qup-memory";
+				power-domains = <&rpmhpd SC7180_CX>;
+				required-opps = <&rpmhpd_opp_low_svs>;
 				status = "disabled";
 			};
 
 			spi0: spi@880000 {
@@ -837,8 +839,10 @@
 						<&gem_noc MASTER_APPSS_PROC 0 &config_noc SLAVE_QUP_0 0>,
 						<&aggre1_noc MASTER_QUP_0 0 &mc_virt SLAVE_EBI1 0>;
 				interconnect-names = "qup-core", "qup-config",
 							"qup-memory";
+				power-domains = <&rpmhpd SC7180_CX>;
+				required-opps = <&rpmhpd_opp_low_svs>;
 				status = "disabled";
 			};
 
 			spi1: spi@884000 {
@@ -889,8 +893,10 @@
 						<&gem_noc MASTER_APPSS_PROC 0 &config_noc SLAVE_QUP_0 0>,
 						<&aggre1_noc MASTER_QUP_0 0 &mc_virt SLAVE_EBI1 0>;
 				interconnect-names = "qup-core", "qup-config",
 							"qup-memory";
+				power-domains = <&rpmhpd SC7180_CX>;
+				required-opps = <&rpmhpd_opp_low_svs>;
 				status = "disabled";
 			};
 
 			uart2: serial@888000 {
@@ -923,8 +929,10 @@
 						<&gem_noc MASTER_APPSS_PROC 0 &config_noc SLAVE_QUP_0 0>,
 						<&aggre1_noc MASTER_QUP_0 0 &mc_virt SLAVE_EBI1 0>;
 				interconnect-names = "qup-core", "qup-config",
 							"qup-memory";
+				power-domains = <&rpmhpd SC7180_CX>;
+				required-opps = <&rpmhpd_opp_low_svs>;
 				status = "disabled";
 			};
 
 			spi3: spi@88c000 {
@@ -975,8 +983,10 @@
 						<&gem_noc MASTER_APPSS_PROC 0 &config_noc SLAVE_QUP_0 0>,
 						<&aggre1_noc MASTER_QUP_0 0 &mc_virt SLAVE_EBI1 0>;
 				interconnect-names = "qup-core", "qup-config",
 							"qup-memory";
+				power-domains = <&rpmhpd SC7180_CX>;
+				required-opps = <&rpmhpd_opp_low_svs>;
 				status = "disabled";
 			};
 
 			uart4: serial@890000 {
@@ -1009,8 +1019,10 @@
 						<&gem_noc MASTER_APPSS_PROC 0 &config_noc SLAVE_QUP_0 0>,
 						<&aggre1_noc MASTER_QUP_0 0 &mc_virt SLAVE_EBI1 0>;
 				interconnect-names = "qup-core", "qup-config",
 							"qup-memory";
+				power-domains = <&rpmhpd SC7180_CX>;
+				required-opps = <&rpmhpd_opp_low_svs>;
 				status = "disabled";
 			};
 
 			spi5: spi@894000 {
@@ -1074,8 +1086,10 @@
 						<&gem_noc MASTER_APPSS_PROC 0 &config_noc SLAVE_QUP_1 0>,
 						<&aggre2_noc MASTER_QUP_1 0 &mc_virt SLAVE_EBI1 0>;
 				interconnect-names = "qup-core", "qup-config",
 							"qup-memory";
+				power-domains = <&rpmhpd SC7180_CX>;
+				required-opps = <&rpmhpd_opp_low_svs>;
 				status = "disabled";
 			};
 
 			spi6: spi@a80000 {
@@ -1126,8 +1140,10 @@
 						<&gem_noc MASTER_APPSS_PROC 0 &config_noc SLAVE_QUP_1 0>,
 						<&aggre2_noc MASTER_QUP_1 0 &mc_virt SLAVE_EBI1 0>;
 				interconnect-names = "qup-core", "qup-config",
 							"qup-memory";
+				power-domains = <&rpmhpd SC7180_CX>;
+				required-opps = <&rpmhpd_opp_low_svs>;
 				status = "disabled";
 			};
 
 			uart7: serial@a84000 {
@@ -1160,8 +1176,10 @@
 						<&gem_noc MASTER_APPSS_PROC 0 &config_noc SLAVE_QUP_1 0>,
 						<&aggre2_noc MASTER_QUP_1 0 &mc_virt SLAVE_EBI1 0>;
 				interconnect-names = "qup-core", "qup-config",
 							"qup-memory";
+				power-domains = <&rpmhpd SC7180_CX>;
+				required-opps = <&rpmhpd_opp_low_svs>;
 				status = "disabled";
 			};
 
 			spi8: spi@a88000 {
@@ -1212,8 +1230,10 @@
 						<&gem_noc MASTER_APPSS_PROC 0 &config_noc SLAVE_QUP_1 0>,
 						<&aggre2_noc MASTER_QUP_1 0 &mc_virt SLAVE_EBI1 0>;
 				interconnect-names = "qup-core", "qup-config",
 							"qup-memory";
+				power-domains = <&rpmhpd SC7180_CX>;
+				required-opps = <&rpmhpd_opp_low_svs>;
 				status = "disabled";
 			};
 
 			uart9: serial@a8c000 {
@@ -1246,8 +1266,10 @@
 						<&gem_noc MASTER_APPSS_PROC 0 &config_noc SLAVE_QUP_1 0>,
 						<&aggre2_noc MASTER_QUP_1 0 &mc_virt SLAVE_EBI1 0>;
 				interconnect-names = "qup-core", "qup-config",
 							"qup-memory";
+				power-domains = <&rpmhpd SC7180_CX>;
+				required-opps = <&rpmhpd_opp_low_svs>;
 				status = "disabled";
 			};
 
 			spi10: spi@a90000 {
@@ -1298,8 +1320,10 @@
 						<&gem_noc MASTER_APPSS_PROC 0 &config_noc SLAVE_QUP_1 0>,
 						<&aggre2_noc MASTER_QUP_1 0 &mc_virt SLAVE_EBI1 0>;
 				interconnect-names = "qup-core", "qup-config",
 							"qup-memory";
+				power-domains = <&rpmhpd SC7180_CX>;
+				required-opps = <&rpmhpd_opp_low_svs>;
 				status = "disabled";
 			};
 
 			spi11: spi@a94000 {
-- 
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of Code Aurora Forum, hosted by The Linux Foundation

Re: [PATCH v3 1/2] PM / Domains: Add support for 'required-opps' to set default perf state

[Rajendra Nayak]

On 7/16/2021 10:43 AM, Rajendra Nayak wrote:
> Some devics within power domains with performance states do not
> support DVFS, but still need to vote on a default/static state
> while they are active. They can express this using the 'required-opps'
> property in device tree, which points to the phandle of the OPP
> supported by the corresponding power-domains.
> 
> Add support to parse this information from DT and then set the
> specified performance state during attach and drop it on detach.
> Also drop/set as part of runtime suspend/resume callbacks.
> 
> Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
> ---
>   drivers/base/power/domain.c | 29 ++++++++++++++++++++++++++++-
>   include/linux/pm_domain.h   |  1 +
>   2 files changed, 29 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> index a934c67..eef5507 100644
> --- a/drivers/base/power/domain.c
> +++ b/drivers/base/power/domain.c
> @@ -917,6 +917,10 @@ static int genpd_runtime_suspend(struct device *dev)
>   	if (irq_safe_dev_in_no_sleep_domain(dev, genpd))
>   		return 0;
>   
> +	/* Drop the default performance state */
> +	if (dev_gpd_data(dev)->default_pstate)
> +		dev_pm_genpd_set_performance_state(dev, 0);
> +
>   	genpd_lock(genpd);
>   	gpd_data->rpm_pstate = genpd_drop_performance_state(dev);
>   	genpd_power_off(genpd, true, 0);
> @@ -937,6 +941,7 @@ static int genpd_runtime_resume(struct device *dev)
>   {
>   	struct generic_pm_domain *genpd;
>   	struct generic_pm_domain_data *gpd_data = dev_gpd_data(dev);
> +	unsigned int default_pstate = gpd_data->default_pstate;
>   	struct gpd_timing_data *td = &gpd_data->td;
>   	bool runtime_pm = pm_runtime_enabled(dev);
>   	ktime_t time_start;
> @@ -968,6 +973,9 @@ static int genpd_runtime_resume(struct device *dev)
>   	if (ret)
>   		return ret;
>   
> +	/* Set the default performance state */
> +	if (default_pstate)
> +		dev_pm_genpd_set_performance_state(dev, default_pstate);
>    out:
>   	/* Measure resume latency. */
>   	time_start = 0;
> @@ -1000,6 +1008,8 @@ static int genpd_runtime_resume(struct device *dev)
>   	genpd_stop_dev(genpd, dev);
>   err_poweroff:
>   	if (!pm_runtime_is_irq_safe(dev) || genpd_is_irq_safe(genpd)) {
> +		if (default_pstate)
> +			dev_pm_genpd_set_performance_state(dev, 0);
>   		genpd_lock(genpd);
>   		gpd_data->rpm_pstate = genpd_drop_performance_state(dev);
>   		genpd_power_off(genpd, true, 0);
> @@ -2598,6 +2608,12 @@ static void genpd_dev_pm_detach(struct device *dev, bool power_off)
>   
>   	dev_dbg(dev, "removing from PM domain %s\n", pd->name);
>   
> +	/* Drop the default performance state */
> +	if (dev_gpd_data(dev)->default_pstate) {
> +		dev_pm_genpd_set_performance_state(dev, 0);
> +		dev_gpd_data(dev)->default_pstate = 0;
> +	}
> +
>   	for (i = 1; i < GENPD_RETRY_MAX_MS; i <<= 1) {
>   		ret = genpd_remove_device(pd, dev);
>   		if (ret != -EAGAIN)
> @@ -2635,9 +2651,10 @@ static void genpd_dev_pm_sync(struct device *dev)
>   static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,
>   				 unsigned int index, bool power_on)
>   {
> +	struct device_node *np;
>   	struct of_phandle_args pd_args;
>   	struct generic_pm_domain *pd;
> -	int ret;
> +	int ret, pstate;
>   
>   	ret = of_parse_phandle_with_args(dev->of_node, "power-domains",
>   				"#power-domain-cells", index, &pd_args);
> @@ -2678,6 +2695,16 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,
>   	if (ret)
>   		genpd_remove_device(pd, dev);
>   
> +	/* Set the default performance state */
> +	np = base_dev->of_node;
> +	if (of_parse_phandle(np, "required-opps", index)) {
> +		pstate = of_get_required_opp_performance_state(np, index);
> +		if (pstate > 0) {
> +			dev_pm_genpd_set_performance_state(dev, pstate);
> +			dev_gpd_data(dev)->default_pstate = pstate;
> +		}
> +	}

I realized this needs better error handling after I sent it out,
I'll fix and respin.

> +
>   	return ret ? -EPROBE_DEFER : 1;
>   }
>   
> diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
> index 21a0577..67017c9 100644
> --- a/include/linux/pm_domain.h
> +++ b/include/linux/pm_domain.h
> @@ -198,6 +198,7 @@ struct generic_pm_domain_data {
>   	struct notifier_block *power_nb;
>   	int cpu;
>   	unsigned int performance_state;
> +	unsigned int default_pstate;
>   	unsigned int rpm_pstate;
>   	ktime_t	next_wakeup;
>   	void *data;
> 

-- 
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of Code Aurora Forum, hosted by The Linux Foundation