thermal/drivers/tegra-bpmp: Check if BPMP supports trip points

Check if BPMP supports thermal trip points, and if not,
do not expose the .set_trips callback to the thermal core
framework. This can happen in virtualized environments
where asynchronous communication with VM BPMP drivers is not
available.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20221129153914.2699041-1-cyndis@kapsi.fi

diff --git a/drivers/thermal/tegra/tegra-bpmp-thermal.c b/drivers/thermal/tegra/tegra-bpmp-thermal.c
index a2879d6..4ffc3bb 100644 (file)
--- a/drivers/thermal/tegra/tegra-bpmp-thermal.c
+++ b/drivers/thermal/tegra/tegra-bpmp-thermal.c
@@ -167,19 +167,69 @@ static int tegra_bpmp_thermal_get_num_zones(struct tegra_bpmp *bpmp,
        return 0;
 }
 
+static int tegra_bpmp_thermal_trips_supported(struct tegra_bpmp *bpmp, bool *supported)
+{
+       struct mrq_thermal_host_to_bpmp_request req;
+       union mrq_thermal_bpmp_to_host_response reply;
+       struct tegra_bpmp_message msg;
+       int err;
+
+       memset(&req, 0, sizeof(req));
+       req.type = CMD_THERMAL_QUERY_ABI;
+       req.query_abi.type = CMD_THERMAL_SET_TRIP;
+
+       memset(&msg, 0, sizeof(msg));
+       msg.mrq = MRQ_THERMAL;
+       msg.tx.data = &req;
+       msg.tx.size = sizeof(req);
+       msg.rx.data = &reply;
+       msg.rx.size = sizeof(reply);
+
+       err = tegra_bpmp_transfer(bpmp, &msg);
+       if (err)
+               return err;
+
+       if (msg.rx.ret == 0) {
+               *supported = true;
+               return 0;
+       } else if (msg.rx.ret == -BPMP_ENODEV) {
+               *supported = false;
+               return 0;
+       } else {
+               return -EINVAL;
+       }
+}
+
 static const struct thermal_zone_device_ops tegra_bpmp_of_thermal_ops = {
        .get_temp = tegra_bpmp_thermal_get_temp,
        .set_trips = tegra_bpmp_thermal_set_trips,
 };
 
+static const struct thermal_zone_device_ops tegra_bpmp_of_thermal_ops_notrips = {
+       .get_temp = tegra_bpmp_thermal_get_temp,
+};
+
 static int tegra_bpmp_thermal_probe(struct platform_device *pdev)
 {
        struct tegra_bpmp *bpmp = dev_get_drvdata(pdev->dev.parent);
+       const struct thermal_zone_device_ops *thermal_ops;
        struct tegra_bpmp_thermal *tegra;
        struct thermal_zone_device *tzd;
        unsigned int i, max_num_zones;
+       bool supported;
        int err;
 
+       err = tegra_bpmp_thermal_trips_supported(bpmp, &supported);
+       if (err) {
+               dev_err(&pdev->dev, "failed to determine if trip points are supported\n");
+               return err;
+       }
+
+       if (supported)
+               thermal_ops = &tegra_bpmp_of_thermal_ops;
+       else
+               thermal_ops = &tegra_bpmp_of_thermal_ops_notrips;
+
        tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
        if (!tegra)
                return -ENOMEM;
@@ -222,7 +272,7 @@ static int tegra_bpmp_thermal_probe(struct platform_device *pdev)
                }
 
                tzd = devm_thermal_of_zone_register(
-                       &pdev->dev, i, zone, &tegra_bpmp_of_thermal_ops);
+                       &pdev->dev, i, zone, thermal_ops);
                if (IS_ERR(tzd)) {
                        if (PTR_ERR(tzd) == -EPROBE_DEFER)
                                return -EPROBE_DEFER;