--- /dev/null
+/*
+ * System Control and Power Interface(SCPI) based hwmon sensor driver
+ *
+ * Copyright (C) 2015 ARM Ltd.
+ * Punit Agrawal <punit.agrawal@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/hwmon.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/scpi_protocol.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/thermal.h>
+
+struct sensor_data {
+ struct scpi_sensor_info info;
+ struct device_attribute dev_attr_input;
+ struct device_attribute dev_attr_label;
+ char input[20];
+ char label[20];
+};
+
+struct scpi_thermal_zone {
+ struct list_head list;
+ int sensor_id;
+ struct scpi_sensors *scpi_sensors;
+ struct thermal_zone_device *tzd;
+};
+
+struct scpi_sensors {
+ struct scpi_ops *scpi_ops;
+ struct sensor_data *data;
+ struct list_head thermal_zones;
+ struct attribute **attrs;
+ struct attribute_group group;
+ const struct attribute_group *groups[2];
+};
+
+static int scpi_read_temp(void *dev, int *temp)
+{
+ struct scpi_thermal_zone *zone = dev;
+ struct scpi_sensors *scpi_sensors = zone->scpi_sensors;
+ struct scpi_ops *scpi_ops = scpi_sensors->scpi_ops;
+ struct sensor_data *sensor = &scpi_sensors->data[zone->sensor_id];
+ u32 value;
+ int ret;
+
+ ret = scpi_ops->sensor_get_value(sensor->info.sensor_id, &value);
+ if (ret)
+ return ret;
+
+ *temp = value;
+ return 0;
+}
+
+/* hwmon callback functions */
+static ssize_t
+scpi_show_sensor(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct scpi_sensors *scpi_sensors = dev_get_drvdata(dev);
+ struct scpi_ops *scpi_ops = scpi_sensors->scpi_ops;
+ struct sensor_data *sensor;
+ u32 value;
+ int ret;
+
+ sensor = container_of(attr, struct sensor_data, dev_attr_input);
+
+ ret = scpi_ops->sensor_get_value(sensor->info.sensor_id, &value);
+ if (ret)
+ return ret;
+
+ return sprintf(buf, "%u\n", value);
+}
+
+static ssize_t
+scpi_show_label(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct sensor_data *sensor;
+
+ sensor = container_of(attr, struct sensor_data, dev_attr_label);
+
+ return sprintf(buf, "%s\n", sensor->info.name);
+}
+
+static void
+unregister_thermal_zones(struct platform_device *pdev,
+ struct scpi_sensors *scpi_sensors)
+{
+ struct list_head *pos;
+
+ list_for_each(pos, &scpi_sensors->thermal_zones) {
+ struct scpi_thermal_zone *zone;
+
+ zone = list_entry(pos, struct scpi_thermal_zone, list);
+ thermal_zone_of_sensor_unregister(&pdev->dev, zone->tzd);
+ }
+}
+
+static struct thermal_zone_of_device_ops scpi_sensor_ops = {
+ .get_temp = scpi_read_temp,
+};
+
+static int scpi_hwmon_probe(struct platform_device *pdev)
+{
+ u16 nr_sensors, i;
+ int num_temp = 0, num_volt = 0, num_current = 0, num_power = 0;
+ struct scpi_ops *scpi_ops;
+ struct device *hwdev, *dev = &pdev->dev;
+ struct scpi_sensors *scpi_sensors;
+ int ret, idx;
+
+ scpi_ops = get_scpi_ops();
+ if (!scpi_ops)
+ return -EPROBE_DEFER;
+
+ ret = scpi_ops->sensor_get_capability(&nr_sensors);
+ if (ret)
+ return ret;
+
+ if (!nr_sensors)
+ return -ENODEV;
+
+ scpi_sensors = devm_kzalloc(dev, sizeof(*scpi_sensors), GFP_KERNEL);
+ if (!scpi_sensors)
+ return -ENOMEM;
+
+ scpi_sensors->data = devm_kcalloc(dev, nr_sensors,
+ sizeof(*scpi_sensors->data), GFP_KERNEL);
+ if (!scpi_sensors->data)
+ return -ENOMEM;
+
+ scpi_sensors->attrs = devm_kcalloc(dev, (nr_sensors * 2) + 1,
+ sizeof(*scpi_sensors->attrs), GFP_KERNEL);
+ if (!scpi_sensors->attrs)
+ return -ENOMEM;
+
+ scpi_sensors->scpi_ops = scpi_ops;
+
+ for (i = 0, idx = 0; i < nr_sensors; i++) {
+ struct sensor_data *sensor = &scpi_sensors->data[idx];
+
+ ret = scpi_ops->sensor_get_info(i, &sensor->info);
+ if (ret)
+ return ret;
+
+ switch (sensor->info.class) {
+ case TEMPERATURE:
+ snprintf(sensor->input, sizeof(sensor->input),
+ "temp%d_input", num_temp + 1);
+ snprintf(sensor->label, sizeof(sensor->input),
+ "temp%d_label", num_temp + 1);
+ num_temp++;
+ break;
+ case VOLTAGE:
+ snprintf(sensor->input, sizeof(sensor->input),
+ "in%d_input", num_volt);
+ snprintf(sensor->label, sizeof(sensor->input),
+ "in%d_label", num_volt);
+ num_volt++;
+ break;
+ case CURRENT:
+ snprintf(sensor->input, sizeof(sensor->input),
+ "curr%d_input", num_current + 1);
+ snprintf(sensor->label, sizeof(sensor->input),
+ "curr%d_label", num_current + 1);
+ num_current++;
+ break;
+ case POWER:
+ snprintf(sensor->input, sizeof(sensor->input),
+ "power%d_input", num_power + 1);
+ snprintf(sensor->label, sizeof(sensor->input),
+ "power%d_label", num_power + 1);
+ num_power++;
+ break;
+ default:
+ continue;
+ }
+
+ sensor->dev_attr_input.attr.mode = S_IRUGO;
+ sensor->dev_attr_input.show = scpi_show_sensor;
+ sensor->dev_attr_input.attr.name = sensor->input;
+
+ sensor->dev_attr_label.attr.mode = S_IRUGO;
+ sensor->dev_attr_label.show = scpi_show_label;
+ sensor->dev_attr_label.attr.name = sensor->label;
+
+ scpi_sensors->attrs[idx << 1] = &sensor->dev_attr_input.attr;
+ scpi_sensors->attrs[(idx << 1) + 1] = &sensor->dev_attr_label.attr;
+
+ sysfs_attr_init(scpi_sensors->attrs[idx << 1]);
+ sysfs_attr_init(scpi_sensors->attrs[(idx << 1) + 1]);
+ idx++;
+ }
+
+ scpi_sensors->group.attrs = scpi_sensors->attrs;
+ scpi_sensors->groups[0] = &scpi_sensors->group;
+
+ platform_set_drvdata(pdev, scpi_sensors);
+
+ hwdev = devm_hwmon_device_register_with_groups(dev,
+ "scpi_sensors", scpi_sensors, scpi_sensors->groups);
+
+ if (IS_ERR(hwdev))
+ return PTR_ERR(hwdev);
+
+ /*
+ * Register the temperature sensors with the thermal framework
+ * to allow their usage in setting up the thermal zones from
+ * device tree.
+ *
+ * NOTE: Not all temperature sensors maybe used for thermal
+ * control
+ */
+ INIT_LIST_HEAD(&scpi_sensors->thermal_zones);
+ for (i = 0; i < nr_sensors; i++) {
+ struct sensor_data *sensor = &scpi_sensors->data[i];
+ struct scpi_thermal_zone *zone;
+
+ if (sensor->info.class != TEMPERATURE)
+ continue;
+
+ zone = devm_kzalloc(dev, sizeof(*zone), GFP_KERNEL);
+ if (!zone) {
+ ret = -ENOMEM;
+ goto unregister_tzd;
+ }
+
+ zone->sensor_id = i;
+ zone->scpi_sensors = scpi_sensors;
+ zone->tzd = thermal_zone_of_sensor_register(dev,
+ sensor->info.sensor_id, zone, &scpi_sensor_ops);
+ /*
+ * The call to thermal_zone_of_sensor_register returns
+ * an error for sensors that are not associated with
+ * any thermal zones or if the thermal subsystem is
+ * not configured.
+ */
+ if (IS_ERR(zone->tzd)) {
+ devm_kfree(dev, zone);
+ continue;
+ }
+ list_add(&zone->list, &scpi_sensors->thermal_zones);
+ }
+
+ return 0;
+
+unregister_tzd:
+ unregister_thermal_zones(pdev, scpi_sensors);
+ return ret;
+}
+
+static int scpi_hwmon_remove(struct platform_device *pdev)
+{
+ struct scpi_sensors *scpi_sensors = platform_get_drvdata(pdev);
+
+ unregister_thermal_zones(pdev, scpi_sensors);
+
+ return 0;
+}
+
+static const struct of_device_id scpi_of_match[] = {
+ {.compatible = "arm,scpi-sensors"},
+ {},
+};
+
+static struct platform_driver scpi_hwmon_platdrv = {
+ .driver = {
+ .name = "scpi-hwmon",
+ .owner = THIS_MODULE,
+ .of_match_table = scpi_of_match,
+ },
+ .probe = scpi_hwmon_probe,
+ .remove = scpi_hwmon_remove,
+};
+module_platform_driver(scpi_hwmon_platdrv);
+
+MODULE_AUTHOR("Punit Agrawal <punit.agrawal@arm.com>");
+MODULE_DESCRIPTION("ARM SCPI HWMON interface driver");
+MODULE_LICENSE("GPL v2");
Code Review / kvmfornfv.git / blobdiff