linux/drivers/hwmon/ltc4215.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Driver for Linear Technology LTC4215 I2C Hot Swap Controller
 *
 * Copyright (C) 2009 Ira W. Snyder <[email protected]>
 *
 * Datasheet:
 * http://www.linear.com/pc/downloadDocument.do?navId=H0,C1,C1003,C1006,C1163,P17572,D12697
 */

#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>

/* Here are names of the chip's registers (a.k.a. commands) */
enum ltc4215_cmd { … };

struct ltc4215_data { … };

static struct ltc4215_data *ltc4215_update_device(struct device *dev)
{ … }

/* Return the voltage from the given register in millivolts */
static int ltc4215_get_voltage(struct device *dev, u8 reg)
{ … }

/* Return the current from the sense resistor in mA */
static unsigned int ltc4215_get_current(struct device *dev)
{ … }

static ssize_t ltc4215_voltage_show(struct device *dev,
				    struct device_attribute *da, char *buf)
{ … }

static ssize_t ltc4215_current_show(struct device *dev,
				    struct device_attribute *da, char *buf)
{ … }

static ssize_t ltc4215_power_show(struct device *dev,
				  struct device_attribute *da, char *buf)
{ … }

static ssize_t ltc4215_alarm_show(struct device *dev,
				  struct device_attribute *da, char *buf)
{ … }

/*
 * These macros are used below in constructing device attribute objects
 * for use with sysfs_create_group() to make a sysfs device file
 * for each register.
 */

/* Construct a sensor_device_attribute structure for each register */

/* Current */
static SENSOR_DEVICE_ATTR_RO(curr1_input, ltc4215_current, 0);
static SENSOR_DEVICE_ATTR_RO(curr1_max_alarm, ltc4215_alarm, 1 << 2);

/* Power (virtual) */
static SENSOR_DEVICE_ATTR_RO(power1_input, ltc4215_power, 0);

/* Input Voltage */
static SENSOR_DEVICE_ATTR_RO(in1_input, ltc4215_voltage, LTC4215_ADIN);
static SENSOR_DEVICE_ATTR_RO(in1_max_alarm, ltc4215_alarm, 1 << 0);
static SENSOR_DEVICE_ATTR_RO(in1_min_alarm, ltc4215_alarm, 1 << 1);

/* Output Voltage */
static SENSOR_DEVICE_ATTR_RO(in2_input, ltc4215_voltage, LTC4215_SOURCE);
static SENSOR_DEVICE_ATTR_RO(in2_min_alarm, ltc4215_alarm, 1 << 3);

/*
 * Finally, construct an array of pointers to members of the above objects,
 * as required for sysfs_create_group()
 */
static struct attribute *ltc4215_attrs[] = …;
ATTRIBUTE_GROUPS(…);

static int ltc4215_probe(struct i2c_client *client)
{ … }

static const struct i2c_device_id ltc4215_id[] = …;
MODULE_DEVICE_TABLE(i2c, ltc4215_id);

/* This is the driver that will be inserted */
static struct i2c_driver ltc4215_driver = …;

module_i2c_driver(…) …;

MODULE_AUTHOR(…) …;
MODULE_DESCRIPTION(…) …;
MODULE_LICENSE(…) …;