Hi, On Tue, Mar 01, 2011 at 07:24:24AM -0500, per.dalen@xxxxxxxxxxxx wrote: > LTC4151 is High Voltage I2C Current and Voltage Monitor from > Linear Technology. > > Signed-off-by: per.dalen@xxxxxxxxxxxx Please provide your full name in addition to your e-mail address. Please also provide Documentation/hwmon/ltc4151. > --- > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig > index 004ff55..619a9da 100644 > --- a/drivers/hwmon/Kconfig > +++ b/drivers/hwmon/Kconfig > @@ -615,6 +615,17 @@ config SENSORS_LM93 > This driver can also be built as a module. If so, the module > will be called lm93. > > +config SENSORS_LTC4151 > + tristate "Linear Technology LTC4151" > + depends on I2C > + default n > + help > + If you say yes here you get support for Linear Technology LTC4151 > + High Voltage and Voltage Monitor I2C interface. > + Datasheet says "High Voltage I2C Current and Voltage Monitor". Please use something similar here, eg "High Voltage Current and Voltage Monitor". > + This driver can also be built as a module. If so, the module will > + be called ltc4151. > + > config SENSORS_LTC4215 > tristate "Linear Technology LTC4215" > depends on I2C && EXPERIMENTAL > diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile > index 2479b3d..42bd7af 100644 > --- a/drivers/hwmon/Makefile > +++ b/drivers/hwmon/Makefile > @@ -78,6 +78,7 @@ obj-$(CONFIG_SENSORS_LM90) += lm90.o > obj-$(CONFIG_SENSORS_LM92) += lm92.o > obj-$(CONFIG_SENSORS_LM93) += lm93.o > obj-$(CONFIG_SENSORS_LM95241) += lm95241.o > +obj-$(CONFIG_SENSORS_LTC4151) += ltc4151.o > obj-$(CONFIG_SENSORS_LTC4215) += ltc4215.o > obj-$(CONFIG_SENSORS_LTC4245) += ltc4245.o > obj-$(CONFIG_SENSORS_LTC4261) += ltc4261.o > diff --git a/drivers/hwmon/ltc4151.c b/drivers/hwmon/ltc4151.c > new file mode 100644 > index 0000000..bf5f031 > --- /dev/null > +++ b/drivers/hwmon/ltc4151.c > @@ -0,0 +1,263 @@ > +/* > + * 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/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 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 > +#define LTC4151_CONTROL 0x06 > + > +struct ltc4151_data { > + struct device *hwmon_dev; > + > + struct mutex update_lock; > + bool valid; > + unsigned long last_updated; /* in jiffies */ > + > + /* Registers */ > + u8 regs[7]; There are 6 relevant registers, not 7. You don't need to read the control register (and you don't use it). > +}; > + > +static struct ltc4151_data *ltc4151_update_device(struct device *dev) > +{ > + struct i2c_client *client = to_i2c_client(dev); > + struct ltc4151_data *data = i2c_get_clientdata(client); > + struct ltc4151_data *ret = data; > + > + mutex_lock(&data->update_lock); > + > + /* The chip's A/D updates 4 times per second */ Datasheet says 6..9 times per second, typical 7.5 times per second. That doesn't mean you have to change the update interval below, but the comment is wrong. > + if (time_after(jiffies, data->last_updated + HZ / 4) || !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; > +} > + > +/* 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 > + * an 20 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. The suggested calculation is not correct, since you assume a 20 mOhm sense resistor. Either assume a 1 mOhm sense resistor, or fix the comment to reflect the assumed 20 mOhm sense resistor (ie the reported value has to be multiplied with 20 before dividing it by the actual sense resistor value in mOhm). > + */ > + val = val; This doesn't really make sense. Add a note saying that no conversion is necessary. > + 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; > +} > + > +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); > +} > + > +/* 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 LTC4151_VALUE(name, ltc4151_cmd_idx) \ > + static SENSOR_DEVICE_ATTR(name, S_IRUGO, \ > + ltc4151_show_value, NULL, ltc4151_cmd_idx) > + I stopped using those macros after noticing that it doesn't add much value and only obfuscates the code. Better use "static SENSOR_DEVICE_ATTR" declarations directly. You won't need the comment describing what you are doing, and the LOC are the same. > +/* > + * Input voltages. > + */ > +LTC4151_VALUE(in1_input, LTC4151_VIN_H); > +LTC4151_VALUE(in2_input, LTC4151_ADIN_H); > + > +/* Currents (via sense resistor) */ > +LTC4151_VALUE(curr1_input, 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_attributes[] = { > + &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, > +}; > + > +static const struct attribute_group ltc4151_group = { > + .attrs = ltc4151_attributes, > +}; > + > +static int ltc4151_probe(struct i2c_client *client, > + const struct i2c_device_id *id) > +{ > + struct i2c_adapter *adapter = client->adapter; > + struct ltc4151_data *data; > + int ret; > + > + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) > + 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); > + > + /* Register sysfs hooks */ > + ret = sysfs_create_group(&client->dev.kobj, <c4151_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, <c4151_group); > +out_sysfs_create_group: > + kfree(data); > +out_kzalloc: > + return ret; > +} > + > +static int ltc4151_remove(struct i2c_client *client) > +{ > + struct ltc4151_data *data = i2c_get_clientdata(client); > + > + hwmon_device_unregister(data->hwmon_dev); > + sysfs_remove_group(&client->dev.kobj, <c4151_group); > + > + kfree(data); > + > + return 0; > +} > + > +static const struct i2c_device_id ltc4151_id[] = { > + { "ltc4151", 0 }, > + { } > +}; > +MODULE_DEVICE_TABLE(i2c, ltc4151_id); > + > +/* This is the driver that will be inserted */ > +static struct i2c_driver ltc4151_driver = { > + .driver = { > + .name = "ltc4151", > + }, > + .probe = ltc4151_probe, > + .remove = ltc4151_remove, > + .id_table = ltc4151_id, > +}; > + > +static int __init ltc4151_init(void) > +{ > + return i2c_add_driver(<c4151_driver); > +} > + > +static void __exit ltc4151_exit(void) > +{ > + i2c_del_driver(<c4151_driver); > +} > + > +MODULE_AUTHOR("AppearTV AS"); MODULE_AUTHOR should be a name (and possibly an e-mail address), not a company. > +MODULE_DESCRIPTION("LTC4151 driver"); > +MODULE_LICENSE("GPL"); > + > +module_init(ltc4151_init); > +module_exit(ltc4151_exit); > > > > _______________________________________________ > lm-sensors mailing list > lm-sensors@xxxxxxxxxxxxxx > http://lists.lm-sensors.org/mailman/listinfo/lm-sensors _______________________________________________ lm-sensors mailing list lm-sensors@xxxxxxxxxxxxxx http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
