cpufreq: cpufreq-dt: Improve debug about matching OPP

During test of new DT OPPs it's very helpful to print the matching
OPP in case of frequency change. So it will be easier to find frequency
rounding issues in the dts file.
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/cpufreq-dt.c

@@ -58,6 +58,8 @@ static int set_target(struct cpufreq_policy *policy, unsigned int index)
 	old_freq = clk_get_rate(cpu_clk) / 1000;
 
 	if (!IS_ERR(cpu_reg)) {
+		unsigned long opp_freq;
+
 		rcu_read_lock();
 		opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_Hz);
 		if (IS_ERR(opp)) {
@@ -67,9 +69,12 @@ static int set_target(struct cpufreq_policy *policy, unsigned int index)
 			return PTR_ERR(opp);
 		}
 		volt = dev_pm_opp_get_voltage(opp);
+		opp_freq = dev_pm_opp_get_freq(opp);
 		rcu_read_unlock();
 		tol = volt * priv->voltage_tolerance / 100;
 		volt_old = regulator_get_voltage(cpu_reg);
+		dev_dbg(cpu_dev, "Found OPP: %ld kHz, %ld uV\n",
+			opp_freq / 1000, volt);
 	}
 
 	dev_dbg(cpu_dev, "%u MHz, %ld mV --> %u MHz, %ld mV\n",