cpufreq: qcom-cpufreq-hw: Fix throttle frequency value on EPSS platforms

On QCOM platforms with EPSS flavour of cpufreq IP a throttled frequency is
obtained from another register REG_DOMAIN_STATE, thus the helper function
qcom_lmh_get_throttle_freq() should be modified accordingly, as for now
it returns gibberish since .reg_current_vote is unset for EPSS hardware.

To exclude a hardcoded magic number 19200 it is replaced by "xo" clock rate
in KHz.

Fixes: 275157b3 ("cpufreq: qcom-cpufreq-hw: Add dcvs interrupt support")
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

drivers/cpufreq/qcom-cpufreq-hw.c

@@ -28,6 +28,7 @@
 
 struct qcom_cpufreq_soc_data {
 	u32 reg_enable;
+	u32 reg_domain_state;
 	u32 reg_dcvs_ctrl;
 	u32 reg_freq_lut;
 	u32 reg_volt_lut;
@@ -280,11 +281,16 @@ static void qcom_get_related_cpus(int index, struct cpumask *m)
 	}
 }
 
-static unsigned int qcom_lmh_get_throttle_freq(struct qcom_cpufreq_data *data)
+static unsigned long qcom_lmh_get_throttle_freq(struct qcom_cpufreq_data *data)
 {
-	unsigned int val = readl_relaxed(data->base + data->soc_data->reg_current_vote);
+	unsigned int lval;
 
-	return (val & 0x3FF) * 19200;
+	if (data->soc_data->reg_current_vote)
+		lval = readl_relaxed(data->base + data->soc_data->reg_current_vote) & 0x3ff;
+	else
+		lval = readl_relaxed(data->base + data->soc_data->reg_domain_state) & 0xff;
+
+	return lval * xo_rate;
 }
 
 static void qcom_lmh_dcvs_notify(struct qcom_cpufreq_data *data)
@@ -294,14 +300,12 @@ static void qcom_lmh_dcvs_notify(struct qcom_cpufreq_data *data)
 	struct device *dev = get_cpu_device(cpu);
 	unsigned long freq_hz, throttled_freq;
 	struct dev_pm_opp *opp;
-	unsigned int freq;
 
 	/*
 	 * Get the h/w throttled frequency, normalize it using the
 	 * registered opp table and use it to calculate thermal pressure.
 	 */
-	freq = qcom_lmh_get_throttle_freq(data);
-	freq_hz = freq * HZ_PER_KHZ;
+	freq_hz = qcom_lmh_get_throttle_freq(data);
 
 	opp = dev_pm_opp_find_freq_floor(dev, &freq_hz);
 	if (IS_ERR(opp) && PTR_ERR(opp) == -ERANGE)
@@ -371,6 +375,7 @@ static const struct qcom_cpufreq_soc_data qcom_soc_data = {
 
 static const struct qcom_cpufreq_soc_data epss_soc_data = {
 	.reg_enable = 0x0,
+	.reg_domain_state = 0x20,
 	.reg_dcvs_ctrl = 0xb0,
 	.reg_freq_lut = 0x100,
 	.reg_volt_lut = 0x200,