hwmon: Versatile Express hwmon driver

hwmon framework driver for Versatile Express sensors, providing
information about board level voltage (only when regulator driver
is not configured), currents, temperature and power/energy usage.
Labels for the values can be defined as DT properties.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Pawel Moll 2012-09-17 18:40:09 +01:00
parent ddffeb8c4d
commit 48ed887724
5 changed files with 295 additions and 0 deletions

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Versatile Express hwmon sensors
-------------------------------
Requires node properties:
- "compatible" value : one of
"arm,vexpress-volt"
"arm,vexpress-amp"
"arm,vexpress-temp"
"arm,vexpress-power"
"arm,vexpress-energy"
- "arm,vexpress-sysreg,func" when controlled via vexpress-sysreg
(see Documentation/devicetree/bindings/arm/vexpress-sysreg.txt
for more details)
Optional node properties:
- label : string describing the monitored value
Example:
energy@0 {
compatible = "arm,vexpress-energy";
arm,vexpress-sysreg,func = <13 0>;
label = "A15 Jcore";
};

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Kernel driver vexpress
======================
Supported systems:
* ARM Ltd. Versatile Express platform
Prefix: 'vexpress'
Datasheets:
* "Hardware Description" sections of the Technical Reference Manuals
for the Versatile Express boards:
http://infocenter.arm.com/help/topic/com.arm.doc.subset.boards.express/index.html
* Section "4.4.14. System Configuration registers" of the V2M-P1 TRM:
http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0447-/index.html
Author: Pawel Moll
Description
-----------
Versatile Express platform (http://www.arm.com/versatileexpress/) is a
reference & prototyping system for ARM Ltd. processors. It can be set up
from a wide range of boards, each of them containing (apart of the main
chip/FPGA) a number of microcontrollers responsible for platform
configuration and control. Theses microcontrollers can also monitor the
board and its environment by a number of internal and external sensors,
providing information about power lines voltages and currents, board
temperature and power usage. Some of them also calculate consumed energy
and provide a cumulative use counter.
The configuration devices are _not_ memory mapped and must be accessed
via a custom interface, abstracted by the "vexpress_config" API.
As these devices are non-discoverable, they must be described in a Device
Tree passed to the kernel. Details of the DT binding for them can be found
in Documentation/devicetree/bindings/hwmon/vexpress.txt.

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@ -1197,6 +1197,14 @@ config SENSORS_TWL4030_MADC
This driver can also be built as a module. If so it will be called
twl4030-madc-hwmon.
config SENSORS_VEXPRESS
tristate "Versatile Express"
depends on VEXPRESS_CONFIG
help
This driver provides support for hardware sensors available on
the ARM Ltd's Versatile Express platform. It can provide wide
range of information like temperature, power, energy.
config SENSORS_VIA_CPUTEMP
tristate "VIA CPU temperature sensor"
depends on X86

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@ -121,6 +121,7 @@ obj-$(CONFIG_SENSORS_TMP102) += tmp102.o
obj-$(CONFIG_SENSORS_TMP401) += tmp401.o
obj-$(CONFIG_SENSORS_TMP421) += tmp421.o
obj-$(CONFIG_SENSORS_TWL4030_MADC)+= twl4030-madc-hwmon.o
obj-$(CONFIG_SENSORS_VEXPRESS) += vexpress.o
obj-$(CONFIG_SENSORS_VIA_CPUTEMP)+= via-cputemp.o
obj-$(CONFIG_SENSORS_VIA686A) += via686a.o
obj-$(CONFIG_SENSORS_VT1211) += vt1211.o

229
drivers/hwmon/vexpress.c Normal file
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/*
* 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 in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* Copyright (C) 2012 ARM Limited
*/
#define DRVNAME "vexpress-hwmon"
#define pr_fmt(fmt) DRVNAME ": " fmt
#include <linux/device.h>
#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/vexpress.h>
struct vexpress_hwmon_data {
struct device *hwmon_dev;
struct vexpress_config_func *func;
};
static ssize_t vexpress_hwmon_name_show(struct device *dev,
struct device_attribute *dev_attr, char *buffer)
{
const char *compatible = of_get_property(dev->of_node, "compatible",
NULL);
return sprintf(buffer, "%s\n", compatible);
}
static ssize_t vexpress_hwmon_label_show(struct device *dev,
struct device_attribute *dev_attr, char *buffer)
{
const char *label = of_get_property(dev->of_node, "label", NULL);
if (!label)
return -ENOENT;
return snprintf(buffer, PAGE_SIZE, "%s\n", label);
}
static ssize_t vexpress_hwmon_u32_show(struct device *dev,
struct device_attribute *dev_attr, char *buffer)
{
struct vexpress_hwmon_data *data = dev_get_drvdata(dev);
int err;
u32 value;
err = vexpress_config_read(data->func, 0, &value);
if (err)
return err;
return snprintf(buffer, PAGE_SIZE, "%u\n", value /
to_sensor_dev_attr(dev_attr)->index);
}
static ssize_t vexpress_hwmon_u64_show(struct device *dev,
struct device_attribute *dev_attr, char *buffer)
{
struct vexpress_hwmon_data *data = dev_get_drvdata(dev);
int err;
u32 value_hi, value_lo;
err = vexpress_config_read(data->func, 0, &value_lo);
if (err)
return err;
err = vexpress_config_read(data->func, 1, &value_hi);
if (err)
return err;
return snprintf(buffer, PAGE_SIZE, "%llu\n",
div_u64(((u64)value_hi << 32) | value_lo,
to_sensor_dev_attr(dev_attr)->index));
}
static DEVICE_ATTR(name, S_IRUGO, vexpress_hwmon_name_show, NULL);
#define VEXPRESS_HWMON_ATTRS(_name, _label_attr, _input_attr) \
struct attribute *vexpress_hwmon_attrs_##_name[] = { \
&dev_attr_name.attr, \
&dev_attr_##_label_attr.attr, \
&sensor_dev_attr_##_input_attr.dev_attr.attr, \
NULL \
}
#if !defined(CONFIG_REGULATOR_VEXPRESS)
static DEVICE_ATTR(in1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, vexpress_hwmon_u32_show,
NULL, 1000);
static VEXPRESS_HWMON_ATTRS(volt, in1_label, in1_input);
static struct attribute_group vexpress_hwmon_group_volt = {
.attrs = vexpress_hwmon_attrs_volt,
};
#endif
static DEVICE_ATTR(curr1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, vexpress_hwmon_u32_show,
NULL, 1000);
static VEXPRESS_HWMON_ATTRS(amp, curr1_label, curr1_input);
static struct attribute_group vexpress_hwmon_group_amp = {
.attrs = vexpress_hwmon_attrs_amp,
};
static DEVICE_ATTR(temp1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, vexpress_hwmon_u32_show,
NULL, 1000);
static VEXPRESS_HWMON_ATTRS(temp, temp1_label, temp1_input);
static struct attribute_group vexpress_hwmon_group_temp = {
.attrs = vexpress_hwmon_attrs_temp,
};
static DEVICE_ATTR(power1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, vexpress_hwmon_u32_show,
NULL, 1);
static VEXPRESS_HWMON_ATTRS(power, power1_label, power1_input);
static struct attribute_group vexpress_hwmon_group_power = {
.attrs = vexpress_hwmon_attrs_power,
};
static DEVICE_ATTR(energy1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
static SENSOR_DEVICE_ATTR(energy1_input, S_IRUGO, vexpress_hwmon_u64_show,
NULL, 1);
static VEXPRESS_HWMON_ATTRS(energy, energy1_label, energy1_input);
static struct attribute_group vexpress_hwmon_group_energy = {
.attrs = vexpress_hwmon_attrs_energy,
};
static struct of_device_id vexpress_hwmon_of_match[] = {
#if !defined(CONFIG_REGULATOR_VEXPRESS)
{
.compatible = "arm,vexpress-volt",
.data = &vexpress_hwmon_group_volt,
},
#endif
{
.compatible = "arm,vexpress-amp",
.data = &vexpress_hwmon_group_amp,
}, {
.compatible = "arm,vexpress-temp",
.data = &vexpress_hwmon_group_temp,
}, {
.compatible = "arm,vexpress-power",
.data = &vexpress_hwmon_group_power,
}, {
.compatible = "arm,vexpress-energy",
.data = &vexpress_hwmon_group_energy,
},
{}
};
MODULE_DEVICE_TABLE(of, vexpress_hwmon_of_match);
static int vexpress_hwmon_probe(struct platform_device *pdev)
{
int err;
const struct of_device_id *match;
struct vexpress_hwmon_data *data;
data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
platform_set_drvdata(pdev, data);
match = of_match_device(vexpress_hwmon_of_match, &pdev->dev);
if (!match)
return -ENODEV;
data->func = vexpress_config_func_get_by_dev(&pdev->dev);
if (!data->func)
return -ENODEV;
err = sysfs_create_group(&pdev->dev.kobj, match->data);
if (err)
goto error;
data->hwmon_dev = hwmon_device_register(&pdev->dev);
if (IS_ERR(data->hwmon_dev)) {
err = PTR_ERR(data->hwmon_dev);
goto error;
}
return 0;
error:
sysfs_remove_group(&pdev->dev.kobj, match->data);
vexpress_config_func_put(data->func);
return err;
}
static int __devexit vexpress_hwmon_remove(struct platform_device *pdev)
{
struct vexpress_hwmon_data *data = platform_get_drvdata(pdev);
const struct of_device_id *match;
hwmon_device_unregister(data->hwmon_dev);
match = of_match_device(vexpress_hwmon_of_match, &pdev->dev);
sysfs_remove_group(&pdev->dev.kobj, match->data);
vexpress_config_func_put(data->func);
return 0;
}
static struct platform_driver vexpress_hwmon_driver = {
.probe = vexpress_hwmon_probe,
.remove = __devexit_p(vexpress_hwmon_remove),
.driver = {
.name = DRVNAME,
.owner = THIS_MODULE,
.of_match_table = vexpress_hwmon_of_match,
},
};
module_platform_driver(vexpress_hwmon_driver);
MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
MODULE_DESCRIPTION("Versatile Express hwmon sensors driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:vexpress-hwmon");