thermal: imx: fix for dependency on cpu-freq

The thermal driver is a standalone driver for monitoring SoC temperature
by enabling thermal sensor, so it can be enabled even when CONFIG_CPU_FREQ
is NOT set. So remove the dependency with CPU_THERMAL.

Introduce dummy function of legacy cooling register/unregister to make
thermal driver probe successfully when CONFIG_CPU_FREQ is NOT set.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

drivers/thermal/Kconfig

@@ -212,7 +212,7 @@ config HISI_THERMAL
 
 config IMX_THERMAL
 	tristate "Temperature sensor driver for Freescale i.MX SoCs"
-	depends on (ARCH_MXC && CPU_THERMAL) || COMPILE_TEST
+	depends on ARCH_MXC || COMPILE_TEST
 	depends on NVMEM || !NVMEM
 	depends on MFD_SYSCON
 	depends on OF

drivers/thermal/imx_thermal.c

@@ -648,15 +648,24 @@ static const struct of_device_id of_imx_thermal_match[] = {
 };
 MODULE_DEVICE_TABLE(of, of_imx_thermal_match);
 
+#ifdef CONFIG_CPU_FREQ
 /*
  * Create cooling device in case no #cooling-cells property is available in
  * CPU node
  */
 static int imx_thermal_register_legacy_cooling(struct imx_thermal_data *data)
 {
-	struct device_node *np = of_get_cpu_node(data->policy->cpu, NULL);
+	struct device_node *np;
 	int ret;
 
+	data->policy = cpufreq_cpu_get(0);
+	if (!data->policy) {
+		pr_debug("%s: CPUFreq policy not found\n", __func__);
+		return -EPROBE_DEFER;
+	}
+
+	np = of_get_cpu_node(data->policy->cpu, NULL);
+
 	if (!np || !of_find_property(np, "#cooling-cells", NULL)) {
 		data->cdev = cpufreq_cooling_register(data->policy);
 		if (IS_ERR(data->cdev)) {
@@ -669,6 +678,24 @@ static int imx_thermal_register_legacy_cooling(struct imx_thermal_data *data)
 	return 0;
 }
 
+static void imx_thermal_unregister_legacy_cooling(struct imx_thermal_data *data)
+{
+	cpufreq_cooling_unregister(data->cdev);
+	cpufreq_cpu_put(data->policy);
+}
+
+#else
+
+static inline int imx_thermal_register_legacy_cooling(struct imx_thermal_data *data)
+{
+	return 0;
+}
+
+static inline void imx_thermal_unregister_legacy_cooling(struct imx_thermal_data *data)
+{
+}
+#endif
+
 static int imx_thermal_probe(struct platform_device *pdev)
 {
 	struct imx_thermal_data *data;
@@ -743,14 +770,11 @@ static int imx_thermal_probe(struct platform_device *pdev)
 	regmap_write(map, data->socdata->sensor_ctrl + REG_SET,
 		     data->socdata->power_down_mask);
 
-	data->policy = cpufreq_cpu_get(0);
-	if (!data->policy) {
-		pr_debug("%s: CPUFreq policy not found\n", __func__);
-		return -EPROBE_DEFER;
-	}
-
 	ret = imx_thermal_register_legacy_cooling(data);
 	if (ret) {
+		if (ret == -EPROBE_DEFER)
+			return ret;
+
 		dev_err(&pdev->dev,
 			"failed to register cpufreq cooling device: %d\n", ret);
 		return ret;
@@ -762,7 +786,7 @@ static int imx_thermal_probe(struct platform_device *pdev)
 		if (ret != -EPROBE_DEFER)
 			dev_err(&pdev->dev,
 				"failed to get thermal clk: %d\n", ret);
-		goto cpufreq_put;
+		goto legacy_cleanup;
 	}
 
 	/*
@@ -775,7 +799,7 @@ static int imx_thermal_probe(struct platform_device *pdev)
 	ret = clk_prepare_enable(data->thermal_clk);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to enable thermal clk: %d\n", ret);
-		goto cpufreq_put;
+		goto legacy_cleanup;
 	}
 
 	data->tz = thermal_zone_device_register("imx_thermal_zone",
@@ -829,9 +853,8 @@ static int imx_thermal_probe(struct platform_device *pdev)
 	thermal_zone_device_unregister(data->tz);
 clk_disable:
 	clk_disable_unprepare(data->thermal_clk);
-cpufreq_put:
+legacy_cleanup:
-	cpufreq_cooling_unregister(data->cdev);
+	imx_thermal_unregister_legacy_cooling(data);
-	cpufreq_cpu_put(data->policy);
 
 	return ret;
 }