--- /dev/null
+// 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");
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