From ea98b29a05e9c70dbe159cbc6254d111059a2bb9 Mon Sep 17 00:00:00 2001 From: Punit Agrawal Date: Thu, 21 May 2015 15:08:45 +0100 Subject: [PATCH] hwmon: Support sensors exported via ARM SCP interface Create a driver to add support for SoC sensors exported by the System Control Processor (SCP) via the System Control and Power Interface (SCPI). The supported sensor types is one of voltage, temperature, current, and power. The sensor labels and values provided by the SCP are exported via the hwmon sysfs interface. Signed-off-by: Punit Agrawal Acked-by: Guenter Roeck Cc: Sudeep Holla --- Documentation/hwmon/scpi-hwmon | 33 ++++++ drivers/hwmon/Kconfig | 8 ++ drivers/hwmon/Makefile | 1 + drivers/hwmon/scpi-hwmon.c | 186 +++++++++++++++++++++++++++++++++ 4 files changed, 228 insertions(+) create mode 100644 Documentation/hwmon/scpi-hwmon create mode 100644 drivers/hwmon/scpi-hwmon.c diff --git a/Documentation/hwmon/scpi-hwmon b/Documentation/hwmon/scpi-hwmon new file mode 100644 index 000000000000..4cfcdf2d5eab --- /dev/null +++ b/Documentation/hwmon/scpi-hwmon @@ -0,0 +1,33 @@ +Kernel driver scpi-hwmon +======================== + +Supported chips: + * Chips based on ARM System Control Processor Interface + Addresses scanned: - + Datasheet: http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0922b/index.html + +Author: Punit Agrawal + +Description +----------- + +This driver supports hardware monitoring for SoC's based on the ARM +System Control Processor (SCP) implementing the System Control +Processor Interface (SCPI). The following sensor types are supported +by the SCP - + + * temperature + * voltage + * current + * power + +The SCP interface provides an API to query the available sensors and +their values which are then exported to userspace by this driver. + +Usage Notes +----------- + +The driver relies on device tree node to indicate the presence of SCPI +support in the kernel. See +Documentation/devicetree/bindings/arm/arm,scpi.txt for details of the +devicetree node. \ No newline at end of file diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index 500b262b89bb..4663693b58f6 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -321,6 +321,14 @@ config SENSORS_APPLESMC Say Y here if you have an applicable laptop and want to experience the awesome power of applesmc. +config SENSORS_ARM_SCPI + tristate "ARM SCPI Sensors" + depends on ARM_SCPI_PROTOCOL + help + This driver provides support for temperature, voltage, current + and power sensors available on ARM Ltd's SCP based platforms. The + actual number and type of sensors exported depend on the platform. + config SENSORS_ASB100 tristate "Asus ASB100 Bach" depends on X86 && I2C diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile index 9e0f3dd2841d..66e7a4715da7 100644 --- a/drivers/hwmon/Makefile +++ b/drivers/hwmon/Makefile @@ -44,6 +44,7 @@ obj-$(CONFIG_SENSORS_ADT7462) += adt7462.o obj-$(CONFIG_SENSORS_ADT7470) += adt7470.o obj-$(CONFIG_SENSORS_ADT7475) += adt7475.o obj-$(CONFIG_SENSORS_APPLESMC) += applesmc.o +obj-$(CONFIG_SENSORS_ARM_SCPI) += scpi-hwmon.o obj-$(CONFIG_SENSORS_ASC7621) += asc7621.o obj-$(CONFIG_SENSORS_ATXP1) += atxp1.o obj-$(CONFIG_SENSORS_CORETEMP) += coretemp.o diff --git a/drivers/hwmon/scpi-hwmon.c b/drivers/hwmon/scpi-hwmon.c new file mode 100644 index 000000000000..c7d1d1423427 --- /dev/null +++ b/drivers/hwmon/scpi-hwmon.c @@ -0,0 +1,186 @@ +/* + * System Control and Power Interface(SCPI) based hwmon sensor driver + * + * Copyright (C) 2015 ARM Ltd. + * Punit Agrawal + * + * 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 +#include +#include +#include +#include +#include + +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_sensors { + struct scpi_ops *scpi_ops; + struct sensor_data *data; + struct attribute **attrs; + struct attribute_group group; + const struct attribute_group *groups[2]; +}; + +/* 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 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; + + 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; i < nr_sensors; i++) { + struct sensor_data *sensor = &scpi_sensors->data[i]; + + 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: + break; + } + + 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[i << 1] = &sensor->dev_attr_input.attr; + scpi_sensors->attrs[(i << 1) + 1] = &sensor->dev_attr_label.attr; + + sysfs_attr_init(scpi_sensors->attrs[i << 1]); + sysfs_attr_init(scpi_sensors->attrs[(i << 1) + 1]); + } + + scpi_sensors->group.attrs = scpi_sensors->attrs; + scpi_sensors->groups[0] = &scpi_sensors->group; + + hwdev = devm_hwmon_device_register_with_groups(dev, + "scpi_sensors", scpi_sensors, scpi_sensors->groups); + + return PTR_ERR_OR_ZERO(hwdev); +} + +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, +}; +module_platform_driver(scpi_hwmon_platdrv); + +MODULE_AUTHOR("Punit Agrawal "); +MODULE_DESCRIPTION("ARM SCPI HWMON interface driver"); +MODULE_LICENSE("GPL v2"); -- 2.39.5