// SPDX-License-Identifier: GPL-2.0-or-later /* * Driver for Linear Technology LTC4261 I2C Negative Voltage Hot Swap Controller * * Copyright (C) 2010 Ericsson AB. * * Derived from: * * Driver for Linear Technology LTC4245 I2C Multiple Supply Hot Swap Controller * Copyright (C) 2008 Ira W. Snyder <[email protected]> * * Datasheet: http://cds.linear.com/docs/Datasheet/42612fb.pdf */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.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> /* chip registers */ #define LTC4261_STATUS … #define LTC4261_FAULT … #define LTC4261_ALERT … #define LTC4261_CONTROL … #define LTC4261_SENSE_H … #define LTC4261_SENSE_L … #define LTC4261_ADIN2_H … #define LTC4261_ADIN2_L … #define LTC4261_ADIN_H … #define LTC4261_ADIN_L … /* * Fault register bits */ #define FAULT_OV … #define FAULT_UV … #define FAULT_OC … struct ltc4261_data { … }; static struct ltc4261_data *ltc4261_update_device(struct device *dev) { … } /* Return the voltage from the given register in mV or mA */ static int ltc4261_get_value(struct ltc4261_data *data, u8 reg) { … } static ssize_t ltc4261_value_show(struct device *dev, struct device_attribute *da, char *buf) { … } static ssize_t ltc4261_bool_show(struct device *dev, struct device_attribute *da, char *buf) { … } /* * Input voltages. */ static SENSOR_DEVICE_ATTR_RO(in1_input, ltc4261_value, LTC4261_ADIN_H); static SENSOR_DEVICE_ATTR_RO(in2_input, ltc4261_value, LTC4261_ADIN2_H); /* * Voltage alarms. The chip has only one set of voltage alarm status bits, * triggered by input voltage alarms. In many designs, those alarms are * associated with the ADIN2 sensor, due to the proximity of the ADIN2 pin * to the OV pin. ADIN2 is, however, not available on all chip variants. * To ensure that the alarm condition is reported to the user, report it * with both voltage sensors. */ static SENSOR_DEVICE_ATTR_RO(in1_min_alarm, ltc4261_bool, FAULT_UV); static SENSOR_DEVICE_ATTR_RO(in1_max_alarm, ltc4261_bool, FAULT_OV); static SENSOR_DEVICE_ATTR_RO(in2_min_alarm, ltc4261_bool, FAULT_UV); static SENSOR_DEVICE_ATTR_RO(in2_max_alarm, ltc4261_bool, FAULT_OV); /* Currents (via sense resistor) */ static SENSOR_DEVICE_ATTR_RO(curr1_input, ltc4261_value, LTC4261_SENSE_H); /* Overcurrent alarm */ static SENSOR_DEVICE_ATTR_RO(curr1_max_alarm, ltc4261_bool, FAULT_OC); static struct attribute *ltc4261_attrs[] = …; ATTRIBUTE_GROUPS(…); static int ltc4261_probe(struct i2c_client *client) { … } static const struct i2c_device_id ltc4261_id[] = …; MODULE_DEVICE_TABLE(i2c, ltc4261_id); /* This is the driver that will be inserted */ static struct i2c_driver ltc4261_driver = …; module_i2c_driver(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …;
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