staging: ti-soc-thermal: defer probe if cpufreq is not ready

When builtin compiled, there is a chance for this driver
be probed before cpufreq driver is up and running. In this
case, the cpucooling device can be wrong initialized.

Thus, this patch makes sure this driver is probed only
when cpufreq driver is ready. Whenever there is no
cpufreq driver registered, the probe will return -EPROBE_DEFER.
Tested-by: NJ Keerthy <j-keerthy@ti.com>
Signed-off-by: NEduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/ti-soc-thermal/ti-bandgap.c

@@ -1305,12 +1305,18 @@ int ti_bandgap_probe(struct platform_device *pdev)
 	for (i = 0; i < bgp->conf->sensor_count; i++) {
 		char *domain;
 
-		if (bgp->conf->sensors[i].register_cooling)
-			bgp->conf->sensors[i].register_cooling(bgp, i);
+		if (bgp->conf->sensors[i].register_cooling) {
+			ret = bgp->conf->sensors[i].register_cooling(bgp, i);
+			if (ret)
+				goto remove_sensors;
+		}
 
-		domain = bgp->conf->sensors[i].domain;
-		if (bgp->conf->expose_sensor)
-			bgp->conf->expose_sensor(bgp, i, domain);
+		if (bgp->conf->expose_sensor) {
+			domain = bgp->conf->sensors[i].domain;
+			ret = bgp->conf->expose_sensor(bgp, i, domain);
+			if (ret)
+				goto remove_last_cooling;
+		}
 	}
 
 	/*
@@ -1329,6 +1335,17 @@ int ti_bandgap_probe(struct platform_device *pdev)
 
 	return 0;
 
+remove_last_cooling:
+	if (bgp->conf->sensors[i].unregister_cooling)
+		bgp->conf->sensors[i].unregister_cooling(bgp, i);
+remove_sensors:
+	for (i--; i >= 0; i--) {
+		if (bgp->conf->sensors[i].unregister_cooling)
+			bgp->conf->sensors[i].unregister_cooling(bgp, i);
+		if (bgp->conf->remove_sensor)
+			bgp->conf->remove_sensor(bgp, i);
+	}
+	ti_bandgap_power(bgp, false);
 disable_clk:
 	if (TI_BANDGAP_HAS(bgp, CLK_CTRL))
 		clk_disable_unprepare(bgp->fclock);

drivers/staging/ti-soc-thermal/ti-thermal-common.c

@@ -339,6 +339,11 @@ int ti_thermal_register_cpu_cooling(struct ti_bandgap *bgp, int id)
 	if (!data)
 		return -EINVAL;
 
+	if (!cpufreq_get_current_driver()) {
+		dev_dbg(bgp->dev, "no cpufreq driver yet\n");
+		return -EPROBE_DEFER;
+	}
+
 	/* Register cooling device */
 	data->cool_dev = cpufreq_cooling_register(cpu_present_mask);
 	if (IS_ERR_OR_NULL(data->cool_dev)) {