Re: [PATCH 4/4] cpufreq: scmi: Support the power scale in micro-Watts in SCMI v3.1

The SCMI v3.1 adds support for power values in micro-Watts. They are not
always in milli-Watts anymore (ignoring the bogo-Watts). Thus, the power
must be converted conditionally before sending to Energy Model. Add the
logic which handles the needed checks and conversions.

Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
---
  drivers/cpufreq/scmi-cpufreq.c | 15 ++++++++++-----
  1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c
index bfd35583d653..513a071845c2 100644
--- a/drivers/cpufreq/scmi-cpufreq.c
+++ b/drivers/cpufreq/scmi-cpufreq.c

@@ -100,7 +100,7 @@ static int __maybe_unused
  scmi_get_cpu_power(struct device *cpu_dev, unsigned long *power,
  		   unsigned long *KHz)
  {
-	bool power_scale_mw = perf_ops->power_scale_mw_get(ph);
+	enum scmi_power_scale power_scale = perf_ops->power_scale_get(ph);
  	unsigned long Hz;
  	int ret, domain;
  

@@ -114,8 +114,8 @@ scmi_get_cpu_power(struct device *cpu_dev, unsigned long *power,
  	if (ret)
  		return ret;
  
-	/* Provide bigger resolution power to the Energy Model */
-	if (power_scale_mw)
+	/* Convert the power to uW if it is mW (ignore bogoW) */
+	if (power_scale == SCMI_POWER_MILLIWATTS)
  		*power *= MICROWATT_PER_MILLIWATT;
  
  	/* The EM framework specifies the frequency in KHz. */

@@ -255,8 +255,9 @@ static int scmi_cpufreq_exit(struct cpufreq_policy *policy)
  static void scmi_cpufreq_register_em(struct cpufreq_policy *policy)
  {
  	struct em_data_callback em_cb = EM_DATA_CB(scmi_get_cpu_power);
-	bool power_scale_mw = perf_ops->power_scale_mw_get(ph);
+	enum scmi_power_scale power_scale = perf_ops->power_scale_get(ph);
  	struct scmi_data *priv = policy->driver_data;
+	bool em_power_scale = false;

  	/*
  	 * This callback will be called for each policy, but we don't need to

@@ -268,9 +269,13 @@ static void scmi_cpufreq_register_em(struct cpufreq_policy *policy)
  	if (!priv->nr_opp)
  		return;
  
+	if (power_scale == SCMI_POWER_MILLIWATTS
+	    || power_scale == SCMI_POWER_MICROWATTS)
+		em_power_scale = true;
+
  	em_dev_register_perf_domain(get_cpu_device(policy->cpu), priv->nr_opp,
  				    &em_cb, priv->opp_shared_cpus,
-				    power_scale_mw);
+				    em_power_scale);
  }
  
  static struct cpufreq_driver scmi_cpufreq_driver = {