This driver adds support for Linear Technology LTC4261 I2C Negative Voltage Hot Swap Controller. Signed-off-by: Guenter Roeck <guenter.roeck@xxxxxxxxxxxx> --- drivers/hwmon/Kconfig | 11 ++ drivers/hwmon/Makefile | 1 + drivers/hwmon/ltc4261.c | 301 +++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 313 insertions(+), 0 deletions(-) create mode 100644 drivers/hwmon/ltc4261.c diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index e19cf8e..dfb300b 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -625,6 +625,17 @@ config SENSORS_LTC4245 This driver can also be built as a module. If so, the module will be called ltc4245. +config SENSORS_LTC4261 + tristate "Linear Technology LTC4261" + depends on I2C && EXPERIMENTAL + default n + help + If you say yes here you get support for Linear Technology LTC4261 + Negative Voltage Hot Swap Controller I2C interface. + + This driver can also be built as a module. If so, the module will + be called ltc4261. + config SENSORS_LM95241 tristate "National Semiconductor LM95241 sensor chip" depends on I2C diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile index 2138ceb..795c805 100644 --- a/drivers/hwmon/Makefile +++ b/drivers/hwmon/Makefile @@ -76,6 +76,7 @@ obj-$(CONFIG_SENSORS_LM93) += lm93.o obj-$(CONFIG_SENSORS_LM95241) += lm95241.o obj-$(CONFIG_SENSORS_LTC4215) += ltc4215.o obj-$(CONFIG_SENSORS_LTC4245) += ltc4245.o +obj-$(CONFIG_SENSORS_LTC4261) += ltc4261.o obj-$(CONFIG_SENSORS_MAX1111) += max1111.o obj-$(CONFIG_SENSORS_MAX1619) += max1619.o obj-$(CONFIG_SENSORS_MAX6650) += max6650.o diff --git a/drivers/hwmon/ltc4261.c b/drivers/hwmon/ltc4261.c new file mode 100644 index 0000000..859019a --- /dev/null +++ b/drivers/hwmon/ltc4261.c @@ -0,0 +1,301 @@ +/* + * Driver for Linear Technology LTC4261 I2C Negative Voltage Hot Swap Controller + * + * Copyright (C) 2010 Ericsson AB. + * + * 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; version 2 of the License. + * + * This driver is based on the ltc4245 driver. + * + * 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> + +/* 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 device *hwmon_dev; + + 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 i2c_client *client = to_i2c_client(dev); + struct ltc4261_data *data = i2c_get_clientdata(client); + struct ltc4261_data *ret = data; + + mutex_lock(&data->update_lock); + + if (time_after(jiffies, data->last_updated + HZ) || !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", + 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; +} + +/* 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) & 0x03); + + 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; +} + +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); +} + +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 i2c_client *client = to_i2c_client(dev); + struct ltc4261_data *data = ltc4261_update_device(dev); + u8 fault; + + if (IS_ERR(data)) + return PTR_ERR(data); + + fault = data->regs[LTC4261_FAULT]; + if (fault & attr->index) /* Clear reported faults in chip register */ + i2c_smbus_write_byte_data(client, LTC4261_FAULT, + fault & ~attr->index); + + return snprintf(buf, PAGE_SIZE, "%d\n", (fault & attr->index) ? 1 : 0); +} + +/* + * 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. + */ + +#define LTC4261_VALUE(name, ltc4261_cmd_idx) \ + static SENSOR_DEVICE_ATTR(name, S_IRUGO, \ + ltc4261_show_value, NULL, ltc4261_cmd_idx) + +#define LTC4261_BOOL(name, mask) \ + static SENSOR_DEVICE_ATTR(name, S_IRUGO, \ + ltc4261_show_bool, NULL, (mask)) + +/* Construct a sensor_device_attribute structure for each register */ + +/* Input voltages */ +LTC4261_VALUE(in1_input, LTC4261_ADIN_H); +LTC4261_VALUE(in2_input, LTC4261_ADIN2_H); + +/* + * Voltage alarms. The chip has only one set of voltage alarm input pins. + * This set of pins is normally used to detect problems with the first (primary) + * voltage, so associate alarms with the first sensor. + */ +LTC4261_BOOL(in1_min_alarm, FAULT_UV); +LTC4261_BOOL(in1_max_alarm, FAULT_OV); + +/* Currents (via sense resistor) */ +LTC4261_VALUE(curr1_input, LTC4261_SENSE_H); + +/* Overcurrent alarm */ +LTC4261_BOOL(curr1_alarm, FAULT_OC); + +/* Finally, construct an array of pointers to members of the above objects, + * as required for sysfs_create_group() + */ +static struct attribute *ltc4261_attributes[] = { + &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_curr1_input.dev_attr.attr, + &sensor_dev_attr_curr1_alarm.dev_attr.attr, + + NULL, +}; + +static const struct attribute_group ltc4261_group = { + .attrs = ltc4261_attributes, +}; + +static int ltc4261_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct i2c_adapter *adapter = client->adapter; + struct ltc4261_data *data; + int ret; + + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) + return -ENODEV; + + if (i2c_smbus_read_byte_data(client, LTC4261_STATUS) < 0) { + dev_err(&client->dev, "Failed to read register %d:%02x:%02x\n", + adapter->id, client->addr, LTC4261_STATUS); + return -ENODEV; + } + + data = kzalloc(sizeof(*data), GFP_KERNEL); + if (!data) { + ret = -ENOMEM; + goto out_kzalloc; + } + + i2c_set_clientdata(client, data); + mutex_init(&data->update_lock); + + /* Clear faults */ + i2c_smbus_write_byte_data(client, LTC4261_FAULT, 0x00); + + /* Register sysfs hooks */ + ret = sysfs_create_group(&client->dev.kobj, <c4261_group); + if (ret) + goto out_sysfs_create_group; + + data->hwmon_dev = hwmon_device_register(&client->dev); + if (IS_ERR(data->hwmon_dev)) { + ret = PTR_ERR(data->hwmon_dev); + goto out_hwmon_device_register; + } + + return 0; + +out_hwmon_device_register: + sysfs_remove_group(&client->dev.kobj, <c4261_group); +out_sysfs_create_group: + kfree(data); +out_kzalloc: + return ret; +} + +static int ltc4261_remove(struct i2c_client *client) +{ + struct ltc4261_data *data = i2c_get_clientdata(client); + + hwmon_device_unregister(data->hwmon_dev); + sysfs_remove_group(&client->dev.kobj, <c4261_group); + + kfree(data); + + return 0; +} + +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, + .remove = ltc4261_remove, + .id_table = ltc4261_id, +}; + +static int __init ltc4261_init(void) +{ + return i2c_add_driver(<c4261_driver); +} + +static void __exit ltc4261_exit(void) +{ + i2c_del_driver(<c4261_driver); +} + +MODULE_AUTHOR("Guenter Roeck>"); +MODULE_DESCRIPTION("LTC4261 driver"); +MODULE_LICENSE("GPL"); + +module_init(ltc4261_init); +module_exit(ltc4261_exit); -- 1.7.0.87.g0901d _______________________________________________ lm-sensors mailing list lm-sensors@xxxxxxxxxxxxxx http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
