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.
Cc: Guenter Roeck <***@roeck-us.net>
Signed-off-by: Tim Harvey <***@gateworks.com>
---
v6:
- fix size of info field
- improve pwm output control documentation
- include unit suffix in divider and offset
- change adc subnode name to gsc-adc
- change fan base to fan subnode
- change adc type to mode
- fix voltage offset scaling
v5:
- fix various checkpatch issues
- correct gsc-hwmon.rst in MAINTAINERS
- encorporate Gunter's feedback:
- switch to SENSOR_DEVICE_ATTR_{RW,RO}
- use tmp value to avoid excessive pointer deference
- simplify shift operation
- scale voffset once
- simplify is_visible function
- remove empty line at end of file
v4:
- adjust for uV offset from device-tree
- remove unnecessary optional write function
- remove register range check
- change dev_err prints to use gsc dev
- hard-code resolution/scaling for raw adcs
- describe units of ADC resolution
- move to using pwm<n>_auto_point<m>_{pwm,temp} for FAN PWM
- ensure space before/after operators
- remove unnecessary parens
- remove more debugging
- add default case and comment for type_voltage
- remove unnecessary index bounds checks for channel
- remove unnecessary clearing of struct fields
- added Documentation/hwmon/gsc-hwmon.rst
v3:
- add voltage_raw input type and supporting fields
- add channel validation to is_visible function
- remove unnecessary channel validation from read/write functions
v2:
- change license comment style
- remove DEBUG
- simplify regmap_bulk_read err check
- remove break after returns in switch statement
- fix fan setpoint buffer address
- remove unnecessary parens
- consistently use struct device *dev pointer
- change license/comment block
- add validation for hwmon child node props
- move parsing of of to own function
- use strlcpy to ensure null termination
- fix static array sizes and removed unnecessary initializers
- dynamically allocate channels
- fix fan input label
- support platform data
- fixed whitespace issues
---
Documentation/hwmon/gsc-hwmon.rst | 53 +++++
Documentation/hwmon/index.rst | 1 +
MAINTAINERS | 3 +
drivers/hwmon/Kconfig | 9 +
drivers/hwmon/Makefile | 1 +
drivers/hwmon/gsc-hwmon.c | 372 ++++++++++++++++++++++++++++++++
include/linux/platform_data/gsc_hwmon.h | 44 ++++
7 files changed, 483 insertions(+)
create mode 100644 Documentation/hwmon/gsc-hwmon.rst
create mode 100644 drivers/hwmon/gsc-hwmon.c
create mode 100644 include/linux/platform_data/gsc_hwmon.h
diff --git a/Documentation/hwmon/gsc-hwmon.rst b/Documentation/hwmon/gsc-hwmon.rst
new file mode 100644
index 00000000..ffac392
--- /dev/null
+++ b/Documentation/hwmon/gsc-hwmon.rst
@@ -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 <***@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.
+
diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index 43cc605..a4fab69 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -58,6 +58,7 @@ Hardware Monitoring Kernel Drivers
ftsteutates
g760a
g762
+ gsc-hwmon
gl518sm
hih6130
ibmaem
diff --git a/MAINTAINERS b/MAINTAINERS
index bb79b60..3f15542 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6846,6 +6846,9 @@ 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
GCC PLUGINS
M: Kees Cook <***@chromium.org>
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 23dfe84..99dae13 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -494,6 +494,15 @@ 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
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 6db5db9..259cba7 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -71,6 +71,7 @@ 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
diff --git a/drivers/hwmon/gsc-hwmon.c b/drivers/hwmon/gsc-hwmon.c
new file mode 100644
index 00000000..c498786
--- /dev/null
+++ b/drivers/hwmon/gsc-hwmon.c
@@ -0,0 +1,372 @@
+// 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 device *dev;
+ struct gsc_hwmon_platform_data *pdata;
+ 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 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->gsc->regmap_hwmon, 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->gsc->regmap_hwmon, 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->gsc->regmap_hwmon, 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, "base", &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-milli-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 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;
+
+ 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 <***@gateworks.com>");
+MODULE_DESCRIPTION("GSC hardware monitor driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/platform_data/gsc_hwmon.h b/include/linux/platform_data/gsc_hwmon.h
new file mode 100644
index 00000000..ec1611a
--- /dev/null
+++ b/include/linux/platform_data/gsc_hwmon.h
@@ -0,0 +1,44 @@
+/* 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
--
2.7.4