[PATCH v8 8/8] OPP: refactor dev_pm_opp_of_register_em() and update related drivers

Lukasz Luba
2020-05-27T10:01:55Z

The Energy Model framework supports not only CPU devices. Drop the CPU
specific interface with cpumask and add struct device. Add also a return
value, user might use it. This new interface provides easy way to create
a simple Energy Model, which then might be used by e.g. thermal subsystem.

Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
---
drivers/cpufreq/cpufreq-dt.c | 2 +-
drivers/cpufreq/imx6q-cpufreq.c | 2 +-
drivers/cpufreq/mediatek-cpufreq.c | 2 +-
drivers/cpufreq/omap-cpufreq.c | 2 +-
drivers/cpufreq/qcom-cpufreq-hw.c | 2 +-
drivers/cpufreq/scpi-cpufreq.c | 2 +-
drivers/cpufreq/vexpress-spc-cpufreq.c | 2 +-
drivers/opp/of.c | 71 ++++++++++++++++----------
include/linux/pm_opp.h | 15 +++++-
9 files changed, 65 insertions(+), 35 deletions(-)

diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c
index 26fe8dfb9ce6..f9f03fd49b83 100644
--- a/drivers/cpufreq/cpufreq-dt.c
+++ b/drivers/cpufreq/cpufreq-dt.c
@@ -275,7 +275,7 @@ static int cpufreq_init(struct cpufreq_policy *policy)
policy->cpuinfo.transition_latency = transition_latency;
policy->dvfs_possible_from_any_cpu = true;

- dev_pm_opp_of_register_em(policy->cpus);
+ dev_pm_opp_of_register_em(cpu_dev, policy->cpus);

return 0;

diff --git a/drivers/cpufreq/imx6q-cpufreq.c b/drivers/cpufreq/imx6q-cpufreq.c
index fdb2ffffbd15..ef7b34c1fd2b 100644
--- a/drivers/cpufreq/imx6q-cpufreq.c
+++ b/drivers/cpufreq/imx6q-cpufreq.c
@@ -193,7 +193,7 @@ static int imx6q_cpufreq_init(struct cpufreq_policy *policy)
policy->clk = clks[ARM].clk;
cpufreq_generic_init(policy, freq_table, transition_latency);
policy->suspend_freq = max_freq;
- dev_pm_opp_of_register_em(policy->cpus);
+ dev_pm_opp_of_register_em(cpu_dev, policy->cpus);

return 0;
}
diff --git a/drivers/cpufreq/mediatek-cpufreq.c b/drivers/cpufreq/mediatek-cpufreq.c
index 0c98dd08273d..7d1212c9b7c8 100644
--- a/drivers/cpufreq/mediatek-cpufreq.c
+++ b/drivers/cpufreq/mediatek-cpufreq.c
@@ -448,7 +448,7 @@ static int mtk_cpufreq_init(struct cpufreq_policy *policy)
policy->driver_data = info;
policy->clk = info->cpu_clk;

- dev_pm_opp_of_register_em(policy->cpus);
+ dev_pm_opp_of_register_em(info->cpu_dev, policy->cpus);

return 0;
}
diff --git a/drivers/cpufreq/omap-cpufreq.c b/drivers/cpufreq/omap-cpufreq.c
index 8d14b42a8c6f..3694bb030df3 100644
--- a/drivers/cpufreq/omap-cpufreq.c
+++ b/drivers/cpufreq/omap-cpufreq.c
@@ -131,7 +131,7 @@ static int omap_cpu_init(struct cpufreq_policy *policy)

/* FIXME: what's the actual transition time? */
cpufreq_generic_init(policy, freq_table, 300 * 1000);
- dev_pm_opp_of_register_em(policy->cpus);
+ dev_pm_opp_of_register_em(mpu_dev, policy->cpus);

return 0;
}
diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
index fc92a8842e25..0a04b6f03b9a 100644
--- a/drivers/cpufreq/qcom-cpufreq-hw.c
+++ b/drivers/cpufreq/qcom-cpufreq-hw.c
@@ -238,7 +238,7 @@ static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
goto error;
}

- dev_pm_opp_of_register_em(policy->cpus);
+ dev_pm_opp_of_register_em(cpu_dev, policy->cpus);

policy->fast_switch_possible = true;

diff --git a/drivers/cpufreq/scpi-cpufreq.c b/drivers/cpufreq/scpi-cpufreq.c
index 20d1f85d5f5a..b0f5388b8854 100644
--- a/drivers/cpufreq/scpi-cpufreq.c
+++ b/drivers/cpufreq/scpi-cpufreq.c
@@ -167,7 +167,7 @@ static int scpi_cpufreq_init(struct cpufreq_policy *policy)

policy->fast_switch_possible = false;

- dev_pm_opp_of_register_em(policy->cpus);
+ dev_pm_opp_of_register_em(cpu_dev, policy->cpus);

return 0;

diff --git a/drivers/cpufreq/vexpress-spc-cpufreq.c b/drivers/cpufreq/vexpress-spc-cpufreq.c
index 83c85d3d67e3..4e8b1dee7c9a 100644
--- a/drivers/cpufreq/vexpress-spc-cpufreq.c
+++ b/drivers/cpufreq/vexpress-spc-cpufreq.c
@@ -450,7 +450,7 @@ static int ve_spc_cpufreq_init(struct cpufreq_policy *policy)
policy->freq_table = freq_table[cur_cluster];
policy->cpuinfo.transition_latency = 1000000; /* 1 ms */

- dev_pm_opp_of_register_em(policy->cpus);
+ dev_pm_opp_of_register_em(cpu_dev, policy->cpus);

if (is_bL_switching_enabled())
per_cpu(cpu_last_req_freq, policy->cpu) =
diff --git a/drivers/opp/of.c b/drivers/opp/of.c
index 5b75829a915d..4500ce46d476 100644
--- a/drivers/opp/of.c
+++ b/drivers/opp/of.c
@@ -1036,18 +1036,18 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_get_of_node);

/*
* Callback function provided to the Energy Model framework upon registration.
- * This computes the power estimated by @CPU at @kHz if it is the frequency
+ * This computes the power estimated by @dev at @kHz if it is the frequency
* of an existing OPP, or at the frequency of the first OPP above @kHz otherwise
* (see dev_pm_opp_find_freq_ceil()). This function updates @kHz to the ceiled
* frequency and @mW to the associated power. The power is estimated as
- * P = C * V^2 * f with C being the CPU's capacitance and V and f respectively
- * the voltage and frequency of the OPP.
+ * P = C * V^2 * f with C being the device's capacitance and V and f
+ * respectively the voltage and frequency of the OPP.
*
- * Returns -ENODEV if the CPU device cannot be found, -EINVAL if the power
- * calculation failed because of missing parameters, 0 otherwise.
+ * Returns -EINVAL if the power calculation failed because of missing
+ * parameters, 0 otherwise.
*/
-static int __maybe_unused _get_cpu_power(unsigned long *mW, unsigned long *kHz,
- struct device *cpu_dev)
+static int __maybe_unused _get_power(unsigned long *mW, unsigned long *kHz,
+ struct device *dev)
{
struct dev_pm_opp *opp;
struct device_node *np;
@@ -1056,7 +1056,7 @@ static int __maybe_unused _get_cpu_power(unsigned long *mW, unsigned long *kHz,
u64 tmp;
int ret;

- np = of_node_get(cpu_dev->of_node);
+ np = of_node_get(dev->of_node);
if (!np)
return -EINVAL;

@@ -1066,7 +1066,7 @@ static int __maybe_unused _get_cpu_power(unsigned long *mW, unsigned long *kHz,
return -EINVAL;

Hz = *kHz * 1000;
- opp = dev_pm_opp_find_freq_ceil(cpu_dev, &Hz);
+ opp = dev_pm_opp_find_freq_ceil(dev, &Hz);
if (IS_ERR(opp))
return -EINVAL;

@@ -1086,30 +1086,38 @@ static int __maybe_unused _get_cpu_power(unsigned long *mW, unsigned long *kHz,

/**
* dev_pm_opp_of_register_em() - Attempt to register an Energy Model
- * @cpus : CPUs for which an Energy Model has to be registered
+ * @dev : Device for which an Energy Model has to be registered
+ * @cpus : CPUs for which an Energy Model has to be registered. For
+ * other type of devices it should be set to NULL.
*
* This checks whether the "dynamic-power-coefficient" devicetree property has
* been specified, and tries to register an Energy Model with it if it has.
+ * Having this property means the voltages are known for OPPs and the EM
+ * might be calculated.
*/
-void dev_pm_opp_of_register_em(struct cpumask *cpus)
+int dev_pm_opp_of_register_em(struct device *dev, struct cpumask *cpus)
{
- struct em_data_callback em_cb = EM_DATA_CB(_get_cpu_power);
- int ret, nr_opp, cpu = cpumask_first(cpus);
- struct device *cpu_dev;
+ struct em_data_callback em_cb = EM_DATA_CB(_get_power);
struct device_node *np;
+ int ret, nr_opp;
u32 cap;

- cpu_dev = get_cpu_device(cpu);
- if (!cpu_dev)
- return;
+ if (IS_ERR_OR_NULL(dev)) {
+ ret = -EINVAL;
+ goto failed;
+ }

- nr_opp = dev_pm_opp_get_opp_count(cpu_dev);
- if (nr_opp <= 0)
- return;
+ nr_opp = dev_pm_opp_get_opp_count(dev);
+ if (nr_opp <= 0) {
+ ret = -EINVAL;
+ goto failed;
+ }

- np = of_node_get(cpu_dev->of_node);
- if (!np)
- return;
+ np = of_node_get(dev->of_node);
+ if (!np) {
+ ret = -EINVAL;
+ goto failed;
+ }

/*
* Register an EM only if the 'dynamic-power-coefficient' property is
@@ -1120,9 +1128,20 @@ void dev_pm_opp_of_register_em(struct cpumask *cpus)
*/
ret = of_property_read_u32(np, "dynamic-power-coefficient", &cap);
of_node_put(np);
- if (ret || !cap)
- return;
+ if (ret || !cap) {
+ dev_dbg(dev, "Couldn't find proper 'dynamic-power-coefficient' in DT\n");
+ ret = -EINVAL;
+ goto failed;
+ }

- em_dev_register_perf_domain(cpu_dev, nr_opp, &em_cb, cpus);
+ ret = em_dev_register_perf_domain(dev, nr_opp, &em_cb, cpus);
+ if (ret)
+ goto failed;
+
+ return 0;
+
+failed:
+ dev_dbg(dev, "Couldn't register Energy Model %d\n", ret);
+ return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_of_register_em);
diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h
index 747861816f4f..8df8b82054e5 100644
--- a/include/linux/pm_opp.h
+++ b/include/linux/pm_opp.h
@@ -11,6 +11,7 @@
#ifndef __LINUX_OPP_H__
#define __LINUX_OPP_H__

+#include <linux/energy_model.h>
#include <linux/err.h>
#include <linux/notifier.h>

@@ -360,7 +361,11 @@ int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpuma
struct device_node *dev_pm_opp_of_get_opp_desc_node(struct device *dev);
struct device_node *dev_pm_opp_get_of_node(struct dev_pm_opp *opp);
int of_get_required_opp_performance_state(struct device_node *np, int index);
-void dev_pm_opp_of_register_em(struct cpumask *cpus);
+int dev_pm_opp_of_register_em(struct device *dev, struct cpumask *cpus);
+static inline void dev_pm_opp_of_unregister_em(struct device *dev)
+{
+ em_dev_unregister_perf_domain(dev);
+}
#else
static inline int dev_pm_opp_of_add_table(struct device *dev)
{
@@ -400,7 +405,13 @@ static inline struct device_node *dev_pm_opp_get_of_node(struct dev_pm_opp *opp)
return NULL;
}

-static inline void dev_pm_opp_of_register_em(struct cpumask *cpus)
+static inline int dev_pm_opp_of_register_em(struct device *dev,
+ struct cpumask *cpus)
+{
+ return -ENOTSUPP;
+}
+
+static inline void dev_pm_opp_of_unregister_em(struct device *dev)
{
}

--
2.17.1