thermal: tegra-bpmp: Handle errors in BPMP response

The return value from tegra_bpmp_transfer indicates the success or
failure of the IPC transaction with BPMP. If the transaction
succeeded, we also need to check the actual command's result code.
Add code to do this.
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20210915085517.1669675-1-mperttunen@nvidia.comSigned-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

drivers/thermal/tegra/tegra-bpmp-thermal.c

@@ -52,6 +52,8 @@ static int tegra_bpmp_thermal_get_temp(void *data, int *out_temp)
 	err = tegra_bpmp_transfer(zone->tegra->bpmp, &msg);
 	if (err)
 		return err;
+	if (msg.rx.ret)
+		return -EINVAL;
 
 	*out_temp = reply.get_temp.temp;
 
@@ -63,6 +65,7 @@ static int tegra_bpmp_thermal_set_trips(void *data, int low, int high)
 	struct tegra_bpmp_thermal_zone *zone = data;
 	struct mrq_thermal_host_to_bpmp_request req;
 	struct tegra_bpmp_message msg;
+	int err;
 
 	memset(&req, 0, sizeof(req));
 	req.type = CMD_THERMAL_SET_TRIP;
@@ -76,7 +79,13 @@ static int tegra_bpmp_thermal_set_trips(void *data, int low, int high)
 	msg.tx.data = &req;
 	msg.tx.size = sizeof(req);
 
-	return tegra_bpmp_transfer(zone->tegra->bpmp, &msg);
+	err = tegra_bpmp_transfer(zone->tegra->bpmp, &msg);
+	if (err)
+		return err;
+	if (msg.rx.ret)
+		return -EINVAL;
+
+	return 0;
 }
 
 static void tz_device_update_work_fn(struct work_struct *work)
@@ -140,6 +149,8 @@ static int tegra_bpmp_thermal_get_num_zones(struct tegra_bpmp *bpmp,
 	err = tegra_bpmp_transfer(bpmp, &msg);
 	if (err)
 		return err;
+	if (msg.rx.ret)
+		return -EINVAL;
 
 	*num_zones = reply.get_num_zones.num;