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hwmon: Add Gateworks System Controller support

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The Gateworks System Controller has a hwmon sub-component that exposes
up to 16 ADC's, some of which are temperature sensors, others which are
voltage inputs. The ADC configuration (register mapping and name) is
configured via device-tree and varies board to board.

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
This commit is contained in:
Tim Harvey 2020-05-15 10:57:08 -07:00 committed by Lee Jones
parent d85234994b
commit 3bce5377ef
7 changed files with 501 additions and 0 deletions
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53
Documentation/hwmon/gsc-hwmon.rst Normal file
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@ -0,0 +1,53 @@
.. SPDX-License-Identifier: GPL-2.0
Kernel driver gsc-hwmon
=======================
Supported chips: Gateworks GSC
Datasheet: http://trac.gateworks.com/wiki/gsc
Author: Tim Harvey <tharvey@gateworks.com>
Description:
------------
This driver supports hardware monitoring for the temperature sensor,
various ADC's connected to the GSC, and optional FAN controller available
on some boards.
Voltage Monitoring
------------------
The voltage inputs are scaled either internally or by the driver depending
on the GSC version and firmware. The values returned by the driver do not need
further scaling. The voltage input labels provide the voltage rail name:
inX_input Measured voltage (mV).
inX_label Name of voltage rail.
Temperature Monitoring
----------------------
Temperatures are measured with 12-bit or 10-bit resolution and are scaled
either internally or by the driver depending on the GSC version and firmware.
The values returned by the driver reflect millidegree Celcius:
tempX_input Measured temperature.
tempX_label Name of temperature input.
PWM Output Control
------------------
The GSC features 1 PWM output that operates in automatic mode where the
PWM value will be scalled depending on 6 temperature boundaries.
The tempeature boundaries are read-write and in millidegree Celcius and the
read-only PWM values range from 0 (off) to 255 (full speed).
Fan speed will be set to minimum (off) when the temperature sensor reads
less than pwm1_auto_point1_temp and maximum when the temperature sensor
equals or exceeds pwm1_auto_point6_temp.
pwm1_auto_point[1-6]_pwm PWM value.
pwm1_auto_point[1-6]_temp Temperature boundary.

1
Documentation/hwmon/index.rst
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@ -60,6 +60,7 @@ Hardware Monitoring Kernel Drivers
ftsteutates
g760a
g762
gsc-hwmon
gl518sm
hih6130
ibmaem

3
MAINTAINERS
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@ -7035,6 +7035,9 @@ S: Maintained
F: Documentation/devicetree/bindings/mfd/gateworks-gsc.yaml
F: drivers/mfd/gateworks-gsc.c
F: include/linux/mfd/gsc.h
F: Documentation/hwmon/gsc-hwmon.rst
F: drivers/hwmon/gsc-hwmon.c
F: include/linux/platform_data/gsc_hwmon.h
GASKET DRIVER FRAMEWORK
M: Rob Springer <rspringer@google.com>

9
drivers/hwmon/Kconfig
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@ -523,6 +523,15 @@ config SENSORS_F75375S
This driver can also be built as a module. If so, the module
will be called f75375s.
config SENSORS_GSC
tristate "Gateworks System Controller ADC"
depends on MFD_GATEWORKS_GSC
help
Support for the Gateworks System Controller A/D converters.
To compile this driver as a module, choose M here:
the module will be called gsc-hwmon.
config SENSORS_MC13783_ADC
tristate "Freescale MC13783/MC13892 ADC"
depends on MFD_MC13XXX

1
drivers/hwmon/Makefile
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@ -74,6 +74,7 @@ obj-$(CONFIG_SENSORS_G760A) += g760a.o
obj-$(CONFIG_SENSORS_G762) += g762.o
obj-$(CONFIG_SENSORS_GL518SM) += gl518sm.o
obj-$(CONFIG_SENSORS_GL520SM) += gl520sm.o
obj-$(CONFIG_SENSORS_GSC) += gsc-hwmon.o
obj-$(CONFIG_SENSORS_GPIO_FAN) += gpio-fan.o
obj-$(CONFIG_SENSORS_HIH6130) += hih6130.o
obj-$(CONFIG_SENSORS_ULTRA45) += ultra45_env.o

390
drivers/hwmon/gsc-hwmon.c Normal file
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@ -0,0 +1,390 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Driver for Gateworks System Controller Hardware Monitor module
*
* Copyright (C) 2020 Gateworks Corporation
*/
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/mfd/gsc.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/platform_data/gsc_hwmon.h>
#define GSC_HWMON_MAX_TEMP_CH 16
#define GSC_HWMON_MAX_IN_CH 16
#define GSC_HWMON_RESOLUTION 12
#define GSC_HWMON_VREF 2500
struct gsc_hwmon_data {
struct gsc_dev *gsc;
struct gsc_hwmon_platform_data *pdata;
struct regmap *regmap;
const struct gsc_hwmon_channel *temp_ch[GSC_HWMON_MAX_TEMP_CH];
const struct gsc_hwmon_channel *in_ch[GSC_HWMON_MAX_IN_CH];
u32 temp_config[GSC_HWMON_MAX_TEMP_CH + 1];
u32 in_config[GSC_HWMON_MAX_IN_CH + 1];
struct hwmon_channel_info temp_info;
struct hwmon_channel_info in_info;
const struct hwmon_channel_info *info[3];
struct hwmon_chip_info chip;
};
static struct regmap_bus gsc_hwmon_regmap_bus = {
.reg_read = gsc_read,
.reg_write = gsc_write,
};
static const struct regmap_config gsc_hwmon_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.cache_type = REGCACHE_NONE,
};
static ssize_t pwm_auto_point_temp_show(struct device *dev,
struct device_attribute *devattr,
char *buf)
{
struct gsc_hwmon_data *hwmon = dev_get_drvdata(dev);
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
u8 reg = hwmon->pdata->fan_base + (2 * attr->index);
u8 regs[2];
int ret;
ret = regmap_bulk_read(hwmon->regmap, reg, regs, 2);
if (ret)
return ret;
ret = regs[0] | regs[1] << 8;
return sprintf(buf, "%d\n", ret * 10);
}
static ssize_t pwm_auto_point_temp_store(struct device *dev,
struct device_attribute *devattr,
const char *buf, size_t count)
{
struct gsc_hwmon_data *hwmon = dev_get_drvdata(dev);
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
u8 reg = hwmon->pdata->fan_base + (2 * attr->index);
u8 regs[2];
long temp;
int err;
if (kstrtol(buf, 10, &temp))
return -EINVAL;
temp = clamp_val(temp, 0, 10000);
temp = DIV_ROUND_CLOSEST(temp, 10);
regs[0] = temp & 0xff;
regs[1] = (temp >> 8) & 0xff;
err = regmap_bulk_write(hwmon->regmap, reg, regs, 2);
if (err)
return err;
return count;
}
static ssize_t pwm_auto_point_pwm_show(struct device *dev,
struct device_attribute *devattr,
char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
return sprintf(buf, "%d\n", 255 * (50 + (attr->index * 10)) / 100);
}
static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point1_pwm, pwm_auto_point_pwm, 0);
static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point1_temp, pwm_auto_point_temp, 0);
static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point2_pwm, pwm_auto_point_pwm, 1);
static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point2_temp, pwm_auto_point_temp, 1);
static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point3_pwm, pwm_auto_point_pwm, 2);
static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point3_temp, pwm_auto_point_temp, 2);
static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point4_pwm, pwm_auto_point_pwm, 3);
static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point4_temp, pwm_auto_point_temp, 3);
static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point5_pwm, pwm_auto_point_pwm, 4);
static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point5_temp, pwm_auto_point_temp, 4);
static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point6_pwm, pwm_auto_point_pwm, 5);
static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point6_temp, pwm_auto_point_temp, 5);
static struct attribute *gsc_hwmon_attributes[] = {
&sensor_dev_attr_pwm1_auto_point1_pwm.dev_attr.attr,
&sensor_dev_attr_pwm1_auto_point1_temp.dev_attr.attr,
&sensor_dev_attr_pwm1_auto_point2_pwm.dev_attr.attr,
&sensor_dev_attr_pwm1_auto_point2_temp.dev_attr.attr,
&sensor_dev_attr_pwm1_auto_point3_pwm.dev_attr.attr,
&sensor_dev_attr_pwm1_auto_point3_temp.dev_attr.attr,
&sensor_dev_attr_pwm1_auto_point4_pwm.dev_attr.attr,
&sensor_dev_attr_pwm1_auto_point4_temp.dev_attr.attr,
&sensor_dev_attr_pwm1_auto_point5_pwm.dev_attr.attr,
&sensor_dev_attr_pwm1_auto_point5_temp.dev_attr.attr,
&sensor_dev_attr_pwm1_auto_point6_pwm.dev_attr.attr,
&sensor_dev_attr_pwm1_auto_point6_temp.dev_attr.attr,
NULL
};
static const struct attribute_group gsc_hwmon_group = {
.attrs = gsc_hwmon_attributes,
};
__ATTRIBUTE_GROUPS(gsc_hwmon);
static int
gsc_hwmon_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
int channel, long *val)
{
struct gsc_hwmon_data *hwmon = dev_get_drvdata(dev);
const struct gsc_hwmon_channel *ch;
int sz, ret;
long tmp;
u8 buf[3];
switch (type) {
case hwmon_in:
ch = hwmon->in_ch[channel];
break;
case hwmon_temp:
ch = hwmon->temp_ch[channel];
break;
default:
return -EOPNOTSUPP;
}
sz = (ch->mode == mode_voltage) ? 3 : 2;
ret = regmap_bulk_read(hwmon->regmap, ch->reg, buf, sz);
if (ret)
return ret;
tmp = 0;
while (sz-- > 0)
tmp |= (buf[sz] << (8 * sz));
switch (ch->mode) {
case mode_temperature:
if (tmp > 0x8000)
tmp -= 0xffff;
break;
case mode_voltage_raw:
tmp = clamp_val(tmp, 0, BIT(GSC_HWMON_RESOLUTION));
/* scale based on ref voltage and ADC resolution */
tmp *= GSC_HWMON_VREF;
tmp >>= GSC_HWMON_RESOLUTION;
/* scale based on optional voltage divider */
if (ch->vdiv[0] && ch->vdiv[1]) {
tmp *= (ch->vdiv[0] + ch->vdiv[1]);
tmp /= ch->vdiv[1];
}
/* adjust by uV offset */
tmp += ch->mvoffset;
break;
case mode_voltage:
/* no adjustment needed */
break;
}
*val = tmp;
return 0;
}
static int
gsc_hwmon_read_string(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, const char **buf)
{
struct gsc_hwmon_data *hwmon = dev_get_drvdata(dev);
switch (type) {
case hwmon_in:
*buf = hwmon->in_ch[channel]->name;
break;
case hwmon_temp:
*buf = hwmon->temp_ch[channel]->name;
break;
default:
return -ENOTSUPP;
}
return 0;
}
static umode_t
gsc_hwmon_is_visible(const void *_data, enum hwmon_sensor_types type, u32 attr,
int ch)
{
return 0444;
}
static const struct hwmon_ops gsc_hwmon_ops = {
.is_visible = gsc_hwmon_is_visible,
.read = gsc_hwmon_read,
.read_string = gsc_hwmon_read_string,
};
static struct gsc_hwmon_platform_data *
gsc_hwmon_get_devtree_pdata(struct device *dev)
{
struct gsc_hwmon_platform_data *pdata;
struct gsc_hwmon_channel *ch;
struct fwnode_handle *child;
struct device_node *fan;
int nchannels;
nchannels = device_get_child_node_count(dev);
if (nchannels == 0)
return ERR_PTR(-ENODEV);
pdata = devm_kzalloc(dev,
sizeof(*pdata) + nchannels * sizeof(*ch),
GFP_KERNEL);
if (!pdata)
return ERR_PTR(-ENOMEM);
ch = (struct gsc_hwmon_channel *)(pdata + 1);
pdata->channels = ch;
pdata->nchannels = nchannels;
/* fan controller base address */
fan = of_find_compatible_node(dev->parent->of_node, NULL, "gw,gsc-fan");
if (fan && of_property_read_u32(fan, "reg", &pdata->fan_base)) {
dev_err(dev, "fan node without base\n");
return ERR_PTR(-EINVAL);
}
/* allocate structures for channels and count instances of each type */
device_for_each_child_node(dev, child) {
if (fwnode_property_read_string(child, "label", &ch->name)) {
dev_err(dev, "channel without label\n");
fwnode_handle_put(child);
return ERR_PTR(-EINVAL);
}
if (fwnode_property_read_u32(child, "reg", &ch->reg)) {
dev_err(dev, "channel without reg\n");
fwnode_handle_put(child);
return ERR_PTR(-EINVAL);
}
if (fwnode_property_read_u32(child, "gw,mode", &ch->mode)) {
dev_err(dev, "channel without mode\n");
fwnode_handle_put(child);
return ERR_PTR(-EINVAL);
}
if (ch->mode > mode_max) {
dev_err(dev, "invalid channel mode\n");
fwnode_handle_put(child);
return ERR_PTR(-EINVAL);
}
if (!fwnode_property_read_u32(child,
"gw,voltage-offset-microvolt",
&ch->mvoffset))
ch->mvoffset /= 1000;
fwnode_property_read_u32_array(child,
"gw,voltage-divider-ohms",
ch->vdiv, ARRAY_SIZE(ch->vdiv));
ch++;
}
return pdata;
}
static int gsc_hwmon_probe(struct platform_device *pdev)
{
struct gsc_dev *gsc = dev_get_drvdata(pdev->dev.parent);
struct device *dev = &pdev->dev;
struct device *hwmon_dev;
struct gsc_hwmon_platform_data *pdata = dev_get_platdata(dev);
struct gsc_hwmon_data *hwmon;
const struct attribute_group **groups;
int i, i_in, i_temp;
if (!pdata) {
pdata = gsc_hwmon_get_devtree_pdata(dev);
if (IS_ERR(pdata))
return PTR_ERR(pdata);
}
hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL);
if (!hwmon)
return -ENOMEM;
hwmon->gsc = gsc;
hwmon->pdata = pdata;
hwmon->regmap = devm_regmap_init(dev, &gsc_hwmon_regmap_bus,
gsc->i2c_hwmon,
&gsc_hwmon_regmap_config);
if (IS_ERR(hwmon->regmap))
return PTR_ERR(hwmon->regmap);
for (i = 0, i_in = 0, i_temp = 0; i < hwmon->pdata->nchannels; i++) {
const struct gsc_hwmon_channel *ch = &pdata->channels[i];
switch (ch->mode) {
case mode_temperature:
if (i_temp == GSC_HWMON_MAX_TEMP_CH) {
dev_err(gsc->dev, "too many temp channels\n");
return -EINVAL;
}
hwmon->temp_ch[i_temp] = ch;
hwmon->temp_config[i_temp] = HWMON_T_INPUT |
HWMON_T_LABEL;
i_temp++;
break;
case mode_voltage:
case mode_voltage_raw:
if (i_in == GSC_HWMON_MAX_IN_CH) {
dev_err(gsc->dev, "too many input channels\n");
return -EINVAL;
}
hwmon->in_ch[i_in] = ch;
hwmon->in_config[i_in] =
HWMON_I_INPUT | HWMON_I_LABEL;
i_in++;
break;
default:
dev_err(gsc->dev, "invalid mode: %d\n", ch->mode);
return -EINVAL;
}
}
/* setup config structures */
hwmon->chip.ops = &gsc_hwmon_ops;
hwmon->chip.info = hwmon->info;
hwmon->info[0] = &hwmon->temp_info;
hwmon->info[1] = &hwmon->in_info;
hwmon->temp_info.type = hwmon_temp;
hwmon->temp_info.config = hwmon->temp_config;
hwmon->in_info.type = hwmon_in;
hwmon->in_info.config = hwmon->in_config;
groups = pdata->fan_base ? gsc_hwmon_groups : NULL;
hwmon_dev = devm_hwmon_device_register_with_info(dev,
KBUILD_MODNAME, hwmon,
&hwmon->chip, groups);
return PTR_ERR_OR_ZERO(hwmon_dev);
}
static const struct of_device_id gsc_hwmon_of_match[] = {
{ .compatible = "gw,gsc-adc", },
{}
};
static struct platform_driver gsc_hwmon_driver = {
.driver = {
.name = "gsc-hwmon",
.of_match_table = gsc_hwmon_of_match,
},
.probe = gsc_hwmon_probe,
};
module_platform_driver(gsc_hwmon_driver);
MODULE_AUTHOR("Tim Harvey <tharvey@gateworks.com>");
MODULE_DESCRIPTION("GSC hardware monitor driver");
MODULE_LICENSE("GPL v2");

44
include/linux/platform_data/gsc_hwmon.h Normal file
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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _GSC_HWMON_H
#define _GSC_HWMON_H
enum gsc_hwmon_mode {
mode_temperature,
mode_voltage,
mode_voltage_raw,
mode_max,
};
/**
* struct gsc_hwmon_channel - configuration parameters
* @reg: I2C register offset
* @mode: channel mode
* @name: channel name
* @mvoffset: voltage offset
* @vdiv: voltage divider array (2 resistor values in milli-ohms)
*/
struct gsc_hwmon_channel {
unsigned int reg;
unsigned int mode;
const char *name;
unsigned int mvoffset;
unsigned int vdiv[2];
};
/**
* struct gsc_hwmon_platform_data - platform data for gsc_hwmon driver
* @channels: pointer to array of gsc_hwmon_channel structures
* describing channels
* @nchannels: number of elements in @channels array
* @vreference: voltage reference (mV)
* @resolution: ADC bit resolution
* @fan_base: register base for FAN controller
*/
struct gsc_hwmon_platform_data {
const struct gsc_hwmon_channel *channels;
int nchannels;
unsigned int resolution;
unsigned int vreference;
unsigned int fan_base;
};
#endif