| /* |
| * 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/of_device.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 { |
| unsigned int scale; |
| 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 { |
| int sensor_id; |
| struct scpi_sensors *scpi_sensors; |
| }; |
| |
| 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 const u32 gxbb_scpi_scale[] = { |
| [TEMPERATURE] = 1, /* (celsius) */ |
| [VOLTAGE] = 1000, /* (millivolts) */ |
| [CURRENT] = 1000, /* (milliamperes) */ |
| [POWER] = 1000000, /* (microwatts) */ |
| [ENERGY] = 1000000, /* (microjoules) */ |
| }; |
| |
| static const u32 scpi_scale[] = { |
| [TEMPERATURE] = 1000, /* (millicelsius) */ |
| [VOLTAGE] = 1000, /* (millivolts) */ |
| [CURRENT] = 1000, /* (milliamperes) */ |
| [POWER] = 1000000, /* (microwatts) */ |
| [ENERGY] = 1000000, /* (microjoules) */ |
| }; |
| |
| static void scpi_scale_reading(u64 *value, struct sensor_data *sensor) |
| { |
| if (scpi_scale[sensor->info.class] != sensor->scale) { |
| *value *= scpi_scale[sensor->info.class]; |
| do_div(*value, sensor->scale); |
| } |
| } |
| |
| 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]; |
| u64 value; |
| int ret; |
| |
| ret = scpi_ops->sensor_get_value(sensor->info.sensor_id, &value); |
| if (ret) |
| return ret; |
| |
| scpi_scale_reading(&value, sensor); |
| |
| *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; |
| u64 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; |
| |
| scpi_scale_reading(&value, sensor); |
| |
| return sprintf(buf, "%llu\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 struct thermal_zone_of_device_ops scpi_sensor_ops = { |
| .get_temp = scpi_read_temp, |
| }; |
| |
| static const struct of_device_id scpi_of_match[] = { |
| {.compatible = "arm,scpi-sensors", .data = &scpi_scale}, |
| {.compatible = "amlogic,meson-gxbb-scpi-sensors", .data = &gxbb_scpi_scale}, |
| {}, |
| }; |
| MODULE_DEVICE_TABLE(of, scpi_of_match); |
| |
| static int scpi_hwmon_probe(struct platform_device *pdev) |
| { |
| u16 nr_sensors, i; |
| const u32 *scale; |
| int num_temp = 0, num_volt = 0, num_current = 0, num_power = 0; |
| int num_energy = 0; |
| struct scpi_ops *scpi_ops; |
| struct device *hwdev, *dev = &pdev->dev; |
| struct scpi_sensors *scpi_sensors; |
| const struct of_device_id *of_id; |
| int idx, ret; |
| |
| 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; |
| |
| of_id = of_match_device(scpi_of_match, &pdev->dev); |
| if (!of_id) { |
| dev_err(&pdev->dev, "Unable to initialize scpi-hwmon data\n"); |
| return -ENODEV; |
| } |
| scale = of_id->data; |
| |
| 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; |
| case ENERGY: |
| snprintf(sensor->input, sizeof(sensor->input), |
| "energy%d_input", num_energy + 1); |
| snprintf(sensor->label, sizeof(sensor->input), |
| "energy%d_label", num_energy + 1); |
| num_energy++; |
| break; |
| default: |
| continue; |
| } |
| |
| sensor->scale = scale[sensor->info.class]; |
| |
| 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 thermal_zone_device *z; |
| struct scpi_thermal_zone *zone; |
| |
| if (sensor->info.class != TEMPERATURE) |
| continue; |
| |
| zone = devm_kzalloc(dev, sizeof(*zone), GFP_KERNEL); |
| if (!zone) |
| return -ENOMEM; |
| |
| zone->sensor_id = i; |
| zone->scpi_sensors = scpi_sensors; |
| z = devm_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(z)) { |
| devm_kfree(dev, zone); |
| continue; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static struct platform_driver scpi_hwmon_platdrv = { |
| .driver = { |
| .name = "scpi-hwmon", |
| .of_match_table = scpi_of_match, |
| }, |
| .probe = scpi_hwmon_probe, |
| }; |
| 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"); |