[PATCH 2/4] OPP: change parameter to device pointer in dev_pm_opp_of_register_em()

[lukasz.luba@arm.com]

From: Lukasz Luba <lukasz.luba@arm.com>

Drop the CPU specific interface with cpumask and switch to struct device.
The Energy Model framework supports both: CPUs and devfreq devices. The new
interface provides easy way to create a Energy Model (EM), which then might
be used in i.e. thermal subsystem.

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/opp/of.c                   | 38 +++++++++++++++---------------
 include/linux/pm_opp.h             | 13 ++++++++--
 8 files changed, 36 insertions(+), 27 deletions(-)

diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c
index d2b5f062a07b..a0db2c4c922a 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);
 
 	return 0;
 
diff --git a/drivers/cpufreq/imx6q-cpufreq.c b/drivers/cpufreq/imx6q-cpufreq.c
index 648a09a1778a..e89a277ea385 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);
 
 	return 0;
 }
diff --git a/drivers/cpufreq/mediatek-cpufreq.c b/drivers/cpufreq/mediatek-cpufreq.c
index 0c98dd08273d..946415f52c50 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);
 
 	return 0;
 }
diff --git a/drivers/cpufreq/omap-cpufreq.c b/drivers/cpufreq/omap-cpufreq.c
index 8d14b42a8c6f..d606b6f9296b 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);
 
 	return 0;
 }
diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
index fc92a8842e25..3810c2aed7a9 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->fast_switch_possible = true;
 
diff --git a/drivers/cpufreq/scpi-cpufreq.c b/drivers/cpufreq/scpi-cpufreq.c
index 20d1f85d5f5a..8e7da2098b73 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);
 
 	return 0;
 
diff --git a/drivers/opp/of.c b/drivers/opp/of.c
index eb2c599ca434..32f522028327 100644
--- a/drivers/opp/of.c
+++ b/drivers/opp/of.c
@@ -1031,18 +1031,18 @@ 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;
@@ -1051,7 +1051,7 @@ 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;
 
@@ -1061,7 +1061,7 @@ 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;
 
@@ -1081,28 +1081,28 @@ 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
  *
  * 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)
+void dev_pm_opp_of_register_em(struct device *dev)
 {
-	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)
+	if (!dev)
 		return;
 
-	nr_opp = dev_pm_opp_get_opp_count(cpu_dev);
+	nr_opp = dev_pm_opp_get_opp_count(dev);
 	if (nr_opp <= 0)
 		return;
 
-	np = of_node_get(cpu_dev->of_node);
+	np = of_node_get(dev->of_node);
 	if (!np)
 		return;
 
@@ -1118,6 +1118,6 @@ void dev_pm_opp_of_register_em(struct cpumask *cpus)
 	if (ret || !cap)
 		return;
 
-	em_register_perf_domain(cpu_dev, nr_opp, &em_cb);
+	em_register_perf_domain(dev, nr_opp, &em_cb);
 }
 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..adf93c484d7c 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);
+void dev_pm_opp_of_register_em(struct device *dev);
+static inline void dev_pm_opp_of_unregister_em(struct device *dev)
+{
+	em_unregister_perf_domain(dev);
+}
 #else
 static inline int dev_pm_opp_of_add_table(struct device *dev)
 {
@@ -400,7 +405,11 @@ 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 void dev_pm_opp_of_register_em(struct device *dev)
+{
+}
+
+static inline void dev_pm_opp_of_unregister_em(struct device *dev)
 {
 }
 
-- 
2.17.1