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Release 4.11 drivers/hwmon/ltc4261.c

Directory: drivers/hwmon
/*
 * 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 <iws@ovro.caltech.edu>
 *
 * Datasheet: http://cds.linear.com/docs/Datasheet/42612fb.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/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	0x00	
/* readonly */

#define LTC4261_FAULT	0x01

#define LTC4261_ALERT	0x02

#define LTC4261_CONTROL	0x03

#define LTC4261_SENSE_H	0x04

#define LTC4261_SENSE_L	0x05

#define LTC4261_ADIN2_H	0x06

#define LTC4261_ADIN2_L	0x07

#define LTC4261_ADIN_H	0x08

#define LTC4261_ADIN_L	0x09

/*
 * Fault register bits
 */

#define FAULT_OV	(1<<0)

#define FAULT_UV	(1<<1)

#define FAULT_OC	(1<<2)


struct ltc4261_data {
	
struct i2c_client *client;

	
struct mutex update_lock;
	
bool valid;
	
unsigned long last_updated;	/* in jiffies */

	/* Registers */
	
u8 regs[10];
};


static struct ltc4261_data *ltc4261_update_device(struct device *dev) { struct ltc4261_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; struct ltc4261_data *ret = data; mutex_lock(&data->update_lock); if (time_after(jiffies, data->last_updated + HZ / 4) || !data->valid) { int i; /* Read registers -- 0x00 to 0x09 */ 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); data->valid = 0; goto abort; } data->regs[i] = val; } data->last_updated = jiffies; data->valid = 1; } abort: mutex_unlock(&data->update_lock); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Guenter Roeck16996.57%375.00%
Frans Meulenbroeks63.43%125.00%
Total175100.00%4100.00%

/* Return the voltage from the given register in mV or mA */
static int ltc4261_get_value(struct ltc4261_data *data, u8 reg) { u32 val; val = (data->regs[reg] << 2) + (data->regs[reg + 1] >> 6); switch (reg) { case LTC4261_ADIN_H: case LTC4261_ADIN2_H: /* 2.5mV resolution. Convert to mV. */ val = val * 25 / 10; break; case LTC4261_SENSE_H: /* * 62.5uV 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 = val * 625 / 10; break; default: /* If we get here, the developer messed up */ WARN_ON_ONCE(1); val = 0; break; } return val; }

Contributors

PersonTokensPropCommitsCommitProp
Guenter Roeck93100.00%1100.00%
Total93100.00%1100.00%


static ssize_t ltc4261_show_value(struct device *dev, struct device_attribute *da, char *buf) { struct sensor_device_attribute *attr = to_sensor_dev_attr(da); struct ltc4261_data *data = ltc4261_update_device(dev); int value; if (IS_ERR(data)) return PTR_ERR(data); value = ltc4261_get_value(data, attr->index); return snprintf(buf, PAGE_SIZE, "%d\n", value); }

Contributors

PersonTokensPropCommitsCommitProp
Guenter Roeck79100.00%1100.00%
Total79100.00%1100.00%


static ssize_t ltc4261_show_bool(struct device *dev, struct device_attribute *da, char *buf) { struct sensor_device_attribute *attr = to_sensor_dev_attr(da); struct ltc4261_data *data = ltc4261_update_device(dev); u8 fault; if (IS_ERR(data)) return PTR_ERR(data); fault = data->regs[LTC4261_FAULT] & attr->index; if (fault) /* Clear reported faults in chip register */ i2c_smbus_write_byte_data(data->client, LTC4261_FAULT, ~fault); return snprintf(buf, PAGE_SIZE, "%d\n", fault ? 1 : 0); }

Contributors

PersonTokensPropCommitsCommitProp
Guenter Roeck102100.00%2100.00%
Total102100.00%2100.00%

/* * Input voltages. */ static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ltc4261_show_value, NULL, LTC4261_ADIN_H); static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, ltc4261_show_value, NULL, 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(in1_min_alarm, S_IRUGO, ltc4261_show_bool, NULL, FAULT_UV); static SENSOR_DEVICE_ATTR(in1_max_alarm, S_IRUGO, ltc4261_show_bool, NULL, FAULT_OV); static SENSOR_DEVICE_ATTR(in2_min_alarm, S_IRUGO, ltc4261_show_bool, NULL, FAULT_UV); static SENSOR_DEVICE_ATTR(in2_max_alarm, S_IRUGO, ltc4261_show_bool, NULL, FAULT_OV); /* Currents (via sense resistor) */ static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ltc4261_show_value, NULL, LTC4261_SENSE_H); /* Overcurrent alarm */ static SENSOR_DEVICE_ATTR(curr1_max_alarm, S_IRUGO, ltc4261_show_bool, NULL, FAULT_OC); static struct attribute *ltc4261_attrs[] = { &sensor_dev_attr_in1_input.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_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_max_alarm.dev_attr.attr, NULL, }; ATTRIBUTE_GROUPS(ltc4261);
static int ltc4261_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct i2c_adapter *adapter = client->adapter; struct device *dev = &client->dev; struct ltc4261_data *data; struct device *hwmon_dev; if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) return -ENODEV; if (i2c_smbus_read_byte_data(client, LTC4261_STATUS) < 0) { dev_err(dev, "Failed to read status register\n"); return -ENODEV; } data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); if (!data) return -ENOMEM; data->client = client; mutex_init(&data->update_lock); /* Clear faults */ i2c_smbus_write_byte_data(client, LTC4261_FAULT, 0x00); hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, data, ltc4261_groups); return PTR_ERR_OR_ZERO(hwmon_dev); }

Contributors

PersonTokensPropCommitsCommitProp
Guenter Roeck15198.69%360.00%
Fengguang Wu10.65%120.00%
Jean Delvare10.65%120.00%
Total153100.00%5100.00%

static const struct i2c_device_id ltc4261_id[] = { {"ltc4261", 0}, {} }; MODULE_DEVICE_TABLE(i2c, ltc4261_id); /* This is the driver that will be inserted */ static struct i2c_driver ltc4261_driver = { .driver = { .name = "ltc4261", }, .probe = ltc4261_probe, .id_table = ltc4261_id, }; module_i2c_driver(ltc4261_driver); MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>"); MODULE_DESCRIPTION("LTC4261 driver"); MODULE_LICENSE("GPL");

Overall Contributors

PersonTokensPropCommitsCommitProp
Guenter Roeck96398.77%654.55%
Frans Meulenbroeks60.62%19.09%
Jean Delvare40.41%218.18%
Axel Lin10.10%19.09%
Fengguang Wu10.10%19.09%
Total975100.00%11100.00%
Directory: drivers/hwmon
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