--- /dev/null
+/*
+ * Driver for Linear Technology LTC2945 I2C Power Monitor
+ *
+ * Copyright (c) 2014 Guenter Roeck
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/jiffies.h>
+#include <linux/regmap.h>
+
+/* chip registers */
+#define LTC2945_CONTROL 0x00
+#define LTC2945_ALERT 0x01
+#define LTC2945_STATUS 0x02
+#define LTC2945_FAULT 0x03
+#define LTC2945_POWER_H 0x05
+#define LTC2945_MAX_POWER_H 0x08
+#define LTC2945_MIN_POWER_H 0x0b
+#define LTC2945_MAX_POWER_THRES_H 0x0e
+#define LTC2945_MIN_POWER_THRES_H 0x11
+#define LTC2945_SENSE_H 0x14
+#define LTC2945_MAX_SENSE_H 0x16
+#define LTC2945_MIN_SENSE_H 0x18
+#define LTC2945_MAX_SENSE_THRES_H 0x1a
+#define LTC2945_MIN_SENSE_THRES_H 0x1c
+#define LTC2945_VIN_H 0x1e
+#define LTC2945_MAX_VIN_H 0x20
+#define LTC2945_MIN_VIN_H 0x22
+#define LTC2945_MAX_VIN_THRES_H 0x24
+#define LTC2945_MIN_VIN_THRES_H 0x26
+#define LTC2945_ADIN_H 0x28
+#define LTC2945_MAX_ADIN_H 0x2a
+#define LTC2945_MIN_ADIN_H 0x2c
+#define LTC2945_MAX_ADIN_THRES_H 0x2e
+#define LTC2945_MIN_ADIN_THRES_H 0x30
+#define LTC2945_MIN_ADIN_THRES_L 0x31
+
+/* Fault register bits */
+
+#define FAULT_ADIN_UV (1 << 0)
+#define FAULT_ADIN_OV (1 << 1)
+#define FAULT_VIN_UV (1 << 2)
+#define FAULT_VIN_OV (1 << 3)
+#define FAULT_SENSE_UV (1 << 4)
+#define FAULT_SENSE_OV (1 << 5)
+#define FAULT_POWER_UV (1 << 6)
+#define FAULT_POWER_OV (1 << 7)
+
+/* Control register bits */
+
+#define CONTROL_MULT_SELECT (1 << 0)
+#define CONTROL_TEST_MODE (1 << 4)
+
+static inline bool is_power_reg(u8 reg)
+{
+ return reg < LTC2945_SENSE_H;
+}
+
+/* Return the value from the given register in uW, mV, or mA */
+static long long ltc2945_reg_to_val(struct device *dev, u8 reg)
+{
+ struct regmap *regmap = dev_get_drvdata(dev);
+ unsigned int control;
+ u8 buf[3];
+ long long val;
+ int ret;
+
+ ret = regmap_bulk_read(regmap, reg, buf,
+ is_power_reg(reg) ? 3 : 2);
+ if (ret < 0)
+ return ret;
+
+ if (is_power_reg(reg)) {
+ /* power */
+ val = (buf[0] << 16) + (buf[1] << 8) + buf[2];
+ } else {
+ /* current, voltage */
+ val = (buf[0] << 4) + (buf[1] >> 4);
+ }
+
+ switch (reg) {
+ case LTC2945_POWER_H:
+ case LTC2945_MAX_POWER_H:
+ case LTC2945_MIN_POWER_H:
+ case LTC2945_MAX_POWER_THRES_H:
+ case LTC2945_MIN_POWER_THRES_H:
+ /*
+ * Convert to uW by assuming current is measured with
+ * an 1mOhm sense resistor, similar to current
+ * measurements.
+ * Control register bit 0 selects if voltage at SENSE+/VDD
+ * or voltage at ADIN is used to measure power.
+ */
+ ret = regmap_read(regmap, LTC2945_CONTROL, &control);
+ if (ret < 0)
+ return ret;
+ if (control & CONTROL_MULT_SELECT) {
+ /* 25 mV * 25 uV = 0.625 uV resolution. */
+ val *= 625LL;
+ } else {
+ /* 0.5 mV * 25 uV = 0.0125 uV resolution. */
+ val = (val * 25LL) >> 1;
+ }
+ break;
+ case LTC2945_VIN_H:
+ case LTC2945_MAX_VIN_H:
+ case LTC2945_MIN_VIN_H:
+ case LTC2945_MAX_VIN_THRES_H:
+ case LTC2945_MIN_VIN_THRES_H:
+ /* 25 mV resolution. Convert to mV. */
+ val *= 25;
+ break;
+ case LTC2945_ADIN_H:
+ case LTC2945_MAX_ADIN_H:
+ case LTC2945_MIN_ADIN_THRES_H:
+ case LTC2945_MAX_ADIN_THRES_H:
+ case LTC2945_MIN_ADIN_H:
+ /* 0.5mV resolution. Convert to mV. */
+ val = val >> 1;
+ break;
+ case LTC2945_SENSE_H:
+ case LTC2945_MAX_SENSE_H:
+ case LTC2945_MIN_SENSE_H:
+ case LTC2945_MAX_SENSE_THRES_H:
+ case LTC2945_MIN_SENSE_THRES_H:
+ /*
+ * 25 uV resolution. Convert to current as measured with
+ * an 1 mOhm sense resistor, in mA. If a different sense
+ * resistor is installed, calculate the actual current by
+ * dividing the reported current by the sense resistor value
+ * in mOhm.
+ */
+ val *= 25;
+ break;
+ default:
+ return -EINVAL;
+ }
+ return val;
+}
+
+static int ltc2945_val_to_reg(struct device *dev, u8 reg,
+ unsigned long val)
+{
+ struct regmap *regmap = dev_get_drvdata(dev);
+ unsigned int control;
+ int ret;
+
+ switch (reg) {
+ case LTC2945_POWER_H:
+ case LTC2945_MAX_POWER_H:
+ case LTC2945_MIN_POWER_H:
+ case LTC2945_MAX_POWER_THRES_H:
+ case LTC2945_MIN_POWER_THRES_H:
+ /*
+ * Convert to register value by assuming current is measured
+ * with an 1mOhm sense resistor, similar to current
+ * measurements.
+ * Control register bit 0 selects if voltage at SENSE+/VDD
+ * or voltage at ADIN is used to measure power, which in turn
+ * determines register calculations.
+ */
+ ret = regmap_read(regmap, LTC2945_CONTROL, &control);
+ if (ret < 0)
+ return ret;
+ if (control & CONTROL_MULT_SELECT) {
+ /* 25 mV * 25 uV = 0.625 uV resolution. */
+ val = DIV_ROUND_CLOSEST(val, 625);
+ } else {
+ /*
+ * 0.5 mV * 25 uV = 0.0125 uV resolution.
+ * Divide first to avoid overflow;
+ * accept loss of accuracy.
+ */
+ val = DIV_ROUND_CLOSEST(val, 25) * 2;
+ }
+ break;
+ case LTC2945_VIN_H:
+ case LTC2945_MAX_VIN_H:
+ case LTC2945_MIN_VIN_H:
+ case LTC2945_MAX_VIN_THRES_H:
+ case LTC2945_MIN_VIN_THRES_H:
+ /* 25 mV resolution. */
+ val /= 25;
+ break;
+ case LTC2945_ADIN_H:
+ case LTC2945_MAX_ADIN_H:
+ case LTC2945_MIN_ADIN_THRES_H:
+ case LTC2945_MAX_ADIN_THRES_H:
+ case LTC2945_MIN_ADIN_H:
+ /* 0.5mV resolution. */
+ val *= 2;
+ break;
+ case LTC2945_SENSE_H:
+ case LTC2945_MAX_SENSE_H:
+ case LTC2945_MIN_SENSE_H:
+ case LTC2945_MAX_SENSE_THRES_H:
+ case LTC2945_MIN_SENSE_THRES_H:
+ /*
+ * 25 uV resolution. Convert to current as measured with
+ * an 1 mOhm sense resistor, in mA. If a different sense
+ * resistor is installed, calculate the actual current by
+ * dividing the reported current by the sense resistor value
+ * in mOhm.
+ */
+ val = DIV_ROUND_CLOSEST(val, 25);
+ break;
+ default:
+ return -EINVAL;
+ }
+ return val;
+}
+
+static ssize_t ltc2945_show_value(struct device *dev,
+ struct device_attribute *da, char *buf)
+{
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+ long long value;
+
+ value = ltc2945_reg_to_val(dev, attr->index);
+ if (value < 0)
+ return value;
+ return snprintf(buf, PAGE_SIZE, "%lld\n", value);
+}
+
+static ssize_t ltc2945_set_value(struct device *dev,
+ struct device_attribute *da,
+ const char *buf, size_t count)
+{
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+ struct regmap *regmap = dev_get_drvdata(dev);
+ u8 reg = attr->index;
+ unsigned long val;
+ u8 regbuf[3];
+ int num_regs;
+ int regval;
+ int ret;
+
+ ret = kstrtoul(buf, 10, &val);
+ if (ret)
+ return ret;
+
+ /* convert to register value, then clamp and write result */
+ regval = ltc2945_val_to_reg(dev, reg, val);
+ if (is_power_reg(reg)) {
+ regval = clamp_val(regval, 0, 0xffffff);
+ regbuf[0] = regval >> 16;
+ regbuf[1] = (regval >> 8) & 0xff;
+ regbuf[2] = regval;
+ num_regs = 3;
+ } else {
+ regval = clamp_val(regval, 0, 0xfff) << 4;
+ regbuf[0] = regval >> 8;
+ regbuf[1] = regval & 0xff;
+ num_regs = 2;
+ }
+ ret = regmap_bulk_write(regmap, reg, regbuf, num_regs);
+ return ret < 0 ? ret : count;
+}
+
+static ssize_t ltc2945_reset_history(struct device *dev,
+ struct device_attribute *da,
+ const char *buf, size_t count)
+{
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+ struct regmap *regmap = dev_get_drvdata(dev);
+ u8 reg = attr->index;
+ int num_regs = is_power_reg(reg) ? 3 : 2;
+ u8 buf_min[3] = { 0xff, 0xff, 0xff };
+ u8 buf_max[3] = { 0, 0, 0 };
+ unsigned long val;
+ int ret;
+
+ ret = kstrtoul(buf, 10, &val);
+ if (ret)
+ return ret;
+ if (val != 1)
+ return -EINVAL;
+
+ ret = regmap_update_bits(regmap, LTC2945_CONTROL, CONTROL_TEST_MODE,
+ CONTROL_TEST_MODE);
+
+ /* Reset minimum */
+ ret = regmap_bulk_write(regmap, reg, buf_min, num_regs);
+ if (ret)
+ return ret;
+
+ switch (reg) {
+ case LTC2945_MIN_POWER_H:
+ reg = LTC2945_MAX_POWER_H;
+ break;
+ case LTC2945_MIN_SENSE_H:
+ reg = LTC2945_MAX_SENSE_H;
+ break;
+ case LTC2945_MIN_VIN_H:
+ reg = LTC2945_MAX_VIN_H;
+ break;
+ case LTC2945_MIN_ADIN_H:
+ reg = LTC2945_MAX_ADIN_H;
+ break;
+ default:
+ WARN_ONCE(1, "Bad register: 0x%x\n", reg);
+ return -EINVAL;
+ }
+ /* Reset maximum */
+ ret = regmap_bulk_write(regmap, reg, buf_max, num_regs);
+
+ /* Try resetting test mode even if there was an error */
+ regmap_update_bits(regmap, LTC2945_CONTROL, CONTROL_TEST_MODE, 0);
+
+ return ret ? : count;
+}
+
+static ssize_t ltc2945_show_bool(struct device *dev,
+ struct device_attribute *da, char *buf)
+{
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+ struct regmap *regmap = dev_get_drvdata(dev);
+ unsigned int fault;
+ int ret;
+
+ ret = regmap_read(regmap, LTC2945_FAULT, &fault);
+ if (ret < 0)
+ return ret;
+
+ fault &= attr->index;
+ if (fault) /* Clear reported faults in chip register */
+ regmap_update_bits(regmap, LTC2945_FAULT, attr->index, 0);
+
+ return snprintf(buf, PAGE_SIZE, "%d\n", !!fault);
+}
+
+/* Input voltages */
+
+static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ltc2945_show_value, NULL,
+ LTC2945_VIN_H);
+static SENSOR_DEVICE_ATTR(in1_min, S_IRUGO | S_IWUSR, ltc2945_show_value,
+ ltc2945_set_value, LTC2945_MIN_VIN_THRES_H);
+static SENSOR_DEVICE_ATTR(in1_max, S_IRUGO | S_IWUSR, ltc2945_show_value,
+ ltc2945_set_value, LTC2945_MAX_VIN_THRES_H);
+static SENSOR_DEVICE_ATTR(in1_lowest, S_IRUGO, ltc2945_show_value, NULL,
+ LTC2945_MIN_VIN_H);
+static SENSOR_DEVICE_ATTR(in1_highest, S_IRUGO, ltc2945_show_value, NULL,
+ LTC2945_MAX_VIN_H);
+static SENSOR_DEVICE_ATTR(in1_reset_history, S_IWUSR, NULL,
+ ltc2945_reset_history, LTC2945_MIN_VIN_H);
+
+static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, ltc2945_show_value, NULL,
+ LTC2945_ADIN_H);
+static SENSOR_DEVICE_ATTR(in2_min, S_IRUGO | S_IWUSR, ltc2945_show_value,
+ ltc2945_set_value, LTC2945_MIN_ADIN_THRES_H);
+static SENSOR_DEVICE_ATTR(in2_max, S_IRUGO | S_IWUSR, ltc2945_show_value,
+ ltc2945_set_value, LTC2945_MAX_ADIN_THRES_H);
+static SENSOR_DEVICE_ATTR(in2_lowest, S_IRUGO, ltc2945_show_value, NULL,
+ LTC2945_MIN_ADIN_H);
+static SENSOR_DEVICE_ATTR(in2_highest, S_IRUGO, ltc2945_show_value, NULL,
+ LTC2945_MAX_ADIN_H);
+static SENSOR_DEVICE_ATTR(in2_reset_history, S_IWUSR, NULL,
+ ltc2945_reset_history, LTC2945_MIN_ADIN_H);
+
+/* Voltage alarms */
+
+static SENSOR_DEVICE_ATTR(in1_min_alarm, S_IRUGO, ltc2945_show_bool, NULL,
+ FAULT_VIN_UV);
+static SENSOR_DEVICE_ATTR(in1_max_alarm, S_IRUGO, ltc2945_show_bool, NULL,
+ FAULT_VIN_OV);
+static SENSOR_DEVICE_ATTR(in2_min_alarm, S_IRUGO, ltc2945_show_bool, NULL,
+ FAULT_ADIN_UV);
+static SENSOR_DEVICE_ATTR(in2_max_alarm, S_IRUGO, ltc2945_show_bool, NULL,
+ FAULT_ADIN_OV);
+
+/* Currents (via sense resistor) */
+
+static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ltc2945_show_value, NULL,
+ LTC2945_SENSE_H);
+static SENSOR_DEVICE_ATTR(curr1_min, S_IRUGO | S_IWUSR, ltc2945_show_value,
+ ltc2945_set_value, LTC2945_MIN_SENSE_THRES_H);
+static SENSOR_DEVICE_ATTR(curr1_max, S_IRUGO | S_IWUSR, ltc2945_show_value,
+ ltc2945_set_value, LTC2945_MAX_SENSE_THRES_H);
+static SENSOR_DEVICE_ATTR(curr1_lowest, S_IRUGO, ltc2945_show_value, NULL,
+ LTC2945_MIN_SENSE_H);
+static SENSOR_DEVICE_ATTR(curr1_highest, S_IRUGO, ltc2945_show_value, NULL,
+ LTC2945_MAX_SENSE_H);
+static SENSOR_DEVICE_ATTR(curr1_reset_history, S_IWUSR, NULL,
+ ltc2945_reset_history, LTC2945_MIN_SENSE_H);
+
+/* Current alarms */
+
+static SENSOR_DEVICE_ATTR(curr1_min_alarm, S_IRUGO, ltc2945_show_bool, NULL,
+ FAULT_SENSE_UV);
+static SENSOR_DEVICE_ATTR(curr1_max_alarm, S_IRUGO, ltc2945_show_bool, NULL,
+ FAULT_SENSE_OV);
+
+/* Power */
+
+static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, ltc2945_show_value, NULL,
+ LTC2945_POWER_H);
+static SENSOR_DEVICE_ATTR(power1_min, S_IRUGO | S_IWUSR, ltc2945_show_value,
+ ltc2945_set_value, LTC2945_MIN_POWER_THRES_H);
+static SENSOR_DEVICE_ATTR(power1_max, S_IRUGO | S_IWUSR, ltc2945_show_value,
+ ltc2945_set_value, LTC2945_MAX_POWER_THRES_H);
+static SENSOR_DEVICE_ATTR(power1_input_lowest, S_IRUGO, ltc2945_show_value,
+ NULL, LTC2945_MIN_POWER_H);
+static SENSOR_DEVICE_ATTR(power1_input_highest, S_IRUGO, ltc2945_show_value,
+ NULL, LTC2945_MAX_POWER_H);
+static SENSOR_DEVICE_ATTR(power1_reset_history, S_IWUSR, NULL,
+ ltc2945_reset_history, LTC2945_MIN_POWER_H);
+
+/* Power alarms */
+
+static SENSOR_DEVICE_ATTR(power1_min_alarm, S_IRUGO, ltc2945_show_bool, NULL,
+ FAULT_POWER_UV);
+static SENSOR_DEVICE_ATTR(power1_max_alarm, S_IRUGO, ltc2945_show_bool, NULL,
+ FAULT_POWER_OV);
+
+static struct attribute *ltc2945_attrs[] = {
+ &sensor_dev_attr_in1_input.dev_attr.attr,
+ &sensor_dev_attr_in1_min.dev_attr.attr,
+ &sensor_dev_attr_in1_max.dev_attr.attr,
+ &sensor_dev_attr_in1_lowest.dev_attr.attr,
+ &sensor_dev_attr_in1_highest.dev_attr.attr,
+ &sensor_dev_attr_in1_reset_history.dev_attr.attr,
+ &sensor_dev_attr_in1_min_alarm.dev_attr.attr,
+ &sensor_dev_attr_in1_max_alarm.dev_attr.attr,
+
+ &sensor_dev_attr_in2_input.dev_attr.attr,
+ &sensor_dev_attr_in2_min.dev_attr.attr,
+ &sensor_dev_attr_in2_max.dev_attr.attr,
+ &sensor_dev_attr_in2_lowest.dev_attr.attr,
+ &sensor_dev_attr_in2_highest.dev_attr.attr,
+ &sensor_dev_attr_in2_reset_history.dev_attr.attr,
+ &sensor_dev_attr_in2_min_alarm.dev_attr.attr,
+ &sensor_dev_attr_in2_max_alarm.dev_attr.attr,
+
+ &sensor_dev_attr_curr1_input.dev_attr.attr,
+ &sensor_dev_attr_curr1_min.dev_attr.attr,
+ &sensor_dev_attr_curr1_max.dev_attr.attr,
+ &sensor_dev_attr_curr1_lowest.dev_attr.attr,
+ &sensor_dev_attr_curr1_highest.dev_attr.attr,
+ &sensor_dev_attr_curr1_reset_history.dev_attr.attr,
+ &sensor_dev_attr_curr1_min_alarm.dev_attr.attr,
+ &sensor_dev_attr_curr1_max_alarm.dev_attr.attr,
+
+ &sensor_dev_attr_power1_input.dev_attr.attr,
+ &sensor_dev_attr_power1_min.dev_attr.attr,
+ &sensor_dev_attr_power1_max.dev_attr.attr,
+ &sensor_dev_attr_power1_input_lowest.dev_attr.attr,
+ &sensor_dev_attr_power1_input_highest.dev_attr.attr,
+ &sensor_dev_attr_power1_reset_history.dev_attr.attr,
+ &sensor_dev_attr_power1_min_alarm.dev_attr.attr,
+ &sensor_dev_attr_power1_max_alarm.dev_attr.attr,
+
+ NULL,
+};
+ATTRIBUTE_GROUPS(ltc2945);
+
+static const struct regmap_config ltc2945_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = LTC2945_MIN_ADIN_THRES_L,
+};
+
+static int ltc2945_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct device *dev = &client->dev;
+ struct device *hwmon_dev;
+ struct regmap *regmap;
+
+ regmap = devm_regmap_init_i2c(client, <c2945_regmap_config);
+ if (IS_ERR(regmap)) {
+ dev_err(dev, "failed to allocate register map\n");
+ return PTR_ERR(regmap);
+ }
+
+ /* Clear faults */
+ regmap_write(regmap, LTC2945_FAULT, 0x00);
+
+ hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
+ regmap,
+ ltc2945_groups);
+ return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const struct i2c_device_id ltc2945_id[] = {
+ {"ltc2945", 0},
+ { }
+};
+
+MODULE_DEVICE_TABLE(i2c, ltc2945_id);
+
+static struct i2c_driver ltc2945_driver = {
+ .driver = {
+ .name = "ltc2945",
+ },
+ .probe = ltc2945_probe,
+ .id_table = ltc2945_id,
+};
+
+module_i2c_driver(ltc2945_driver);
+
+MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
+MODULE_DESCRIPTION("LTC2945 driver");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff