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Release 4.14 drivers/hwmon/ltc4151.c

Directory: drivers/hwmon
/*
 * Driver for Linear Technology LTC4151 High Voltage I2C Current
 * and Voltage Monitor
 *
 * Copyright (C) 2011 AppearTV AS
 *
 * Derived from:
 *
 *  Driver for Linear Technology LTC4261 I2C Negative Voltage Hot
 *  Swap Controller
 *  Copyright (C) 2010 Ericsson AB.
 *
 * Datasheet: http://www.linear.com/docs/Datasheet/4151fc.pdf
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.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 LTC4151_SENSE_H	0x00

#define LTC4151_SENSE_L	0x01

#define LTC4151_VIN_H	0x02

#define LTC4151_VIN_L	0x03

#define LTC4151_ADIN_H	0x04

#define LTC4151_ADIN_L	0x05


struct ltc4151_data {
	
struct i2c_client *client;

	
struct mutex update_lock;
	
bool valid;
	
unsigned long last_updated; /* in jiffies */
	
unsigned int shunt; /* in micro ohms */

	/* Registers */
	
u8 regs[6];
};


static struct ltc4151_data *ltc4151_update_device(struct device *dev) { struct ltc4151_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; struct ltc4151_data *ret = data; mutex_lock(&data->update_lock); /* * The chip's A/D updates 6 times per second * (Conversion Rate 6 - 9 Hz) */ if (time_after(jiffies, data->last_updated + HZ / 6) || !data->valid) { int i; dev_dbg(&client->dev, "Starting ltc4151 update\n"); /* Read all registers */ for (i = 0; i < ARRAY_SIZE(data->regs); i++) { int val; val = i2c_smbus_read_byte_data(client, i); if (unlikely(val < 0)) { dev_dbg(dev, "Failed to read ADC value: error %d\n", val); ret = ERR_PTR(val); goto abort; } data->regs[i] = val; } data->last_updated = jiffies; data->valid = 1; } abort: mutex_unlock(&data->update_lock); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Per Dalén17396.11%150.00%
Axel Lin73.89%150.00%
Total180100.00%2100.00%

/* Return the voltage from the given register in mV */
static int ltc4151_get_value(struct ltc4151_data *data, u8 reg) { u32 val; val = (data->regs[reg] << 4) + (data->regs[reg + 1] >> 4); switch (reg) { case LTC4151_ADIN_H: /* 500uV resolution. Convert to mV. */ val = val * 500 / 1000; break; case LTC4151_SENSE_H: /* * 20uV resolution. Convert to current as measured with * a given sense resistor, in mA. */ val = val * 20 * 1000 / data->shunt; break; case LTC4151_VIN_H: /* 25 mV per increment */ val = val * 25; break; default: /* If we get here, the developer messed up */ WARN_ON_ONCE(1); val = 0; break; } return val; }

Contributors

PersonTokensPropCommitsCommitProp
Per Dalén9893.33%150.00%
Daniel Golle76.67%150.00%
Total105100.00%2100.00%


static ssize_t ltc4151_show_value(struct device *dev, struct device_attribute *da, char *buf) { struct sensor_device_attribute *attr = to_sensor_dev_attr(da); struct ltc4151_data *data = ltc4151_update_device(dev); int value; if (IS_ERR(data)) return PTR_ERR(data); value = ltc4151_get_value(data, attr->index); return snprintf(buf, PAGE_SIZE, "%d\n", value); }

Contributors

PersonTokensPropCommitsCommitProp
Per Dalén79100.00%1100.00%
Total79100.00%1100.00%

/* * Input voltages. */ static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ltc4151_show_value, NULL, LTC4151_VIN_H); static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, ltc4151_show_value, NULL, LTC4151_ADIN_H); /* Currents (via sense resistor) */ static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ltc4151_show_value, NULL, LTC4151_SENSE_H); /* * Finally, construct an array of pointers to members of the above objects, * as required for sysfs_create_group() */ static struct attribute *ltc4151_attrs[] = { &sensor_dev_attr_in1_input.dev_attr.attr, &sensor_dev_attr_in2_input.dev_attr.attr, &sensor_dev_attr_curr1_input.dev_attr.attr, NULL, }; ATTRIBUTE_GROUPS(ltc4151);
static int ltc4151_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct i2c_adapter *adapter = client->adapter; struct device *dev = &client->dev; struct ltc4151_data *data; struct device *hwmon_dev; u32 shunt; if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) return -ENODEV; data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); if (!data) return -ENOMEM; if (of_property_read_u32(client->dev.of_node, "shunt-resistor-micro-ohms", &shunt)) shunt = 1000; /* 1 mOhm if not set via DT */ if (shunt == 0) return -EINVAL; data->shunt = shunt; data->client = client; mutex_init(&data->update_lock); hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, data, ltc4151_groups); return PTR_ERR_OR_ZERO(hwmon_dev); }

Contributors

PersonTokensPropCommitsCommitProp
Per Dalén9056.60%125.00%
Daniel Golle4025.16%125.00%
Axel Lin2415.09%125.00%
Guenter Roeck53.14%125.00%
Total159100.00%4100.00%

static const struct i2c_device_id ltc4151_id[] = { { "ltc4151", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, ltc4151_id); static const struct of_device_id ltc4151_match[] = { { .compatible = "lltc,ltc4151" }, {}, }; MODULE_DEVICE_TABLE(of, ltc4151_match); /* This is the driver that will be inserted */ static struct i2c_driver ltc4151_driver = { .driver = { .name = "ltc4151", .of_match_table = of_match_ptr(ltc4151_match), }, .probe = ltc4151_probe, .id_table = ltc4151_id, }; module_i2c_driver(ltc4151_driver); MODULE_AUTHOR("Per Dalen <per.dalen@appeartv.com>"); MODULE_DESCRIPTION("LTC4151 driver"); MODULE_LICENSE("GPL");

Overall Contributors

PersonTokensPropCommitsCommitProp
Per Dalén66182.52%111.11%
Daniel Golle8110.11%111.11%
Axel Lin404.99%222.22%
Guenter Roeck91.12%333.33%
Javier Martinez Canillas70.87%111.11%
Jean Delvare30.37%111.11%
Total801100.00%9100.00%
Directory: drivers/hwmon
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