On Tue, Oct 11, 2016 at 10:26:31AM +1300, Chris Packham wrote: > Add support for the tc654 and tc655 fan controllers from Microchip. > > http://ww1.microchip.com/downloads/en/DeviceDoc/20001734C.pdf > > Signed-off-by: Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx> > Acked-by: Rob Herring <robh@xxxxxxxxxx> Applied to -next (after fixing continuation line alignments). Guenter > --- > Changes in v4: > - tab-align values in #defines > - ensure locking in set_pwm covers updating cached values > - populate the cached value for the config register in tc654_probe() > > Changes in v3: > - typofix in documentation > - add missing value to tc654_pwm_map, re-generate based on datasheet. > - remove unnecessary hwmon_dev member from struct tc654_data > - bug fixes in set_fan_min() and show_pwm_mode() > - miscellaneous style fixes > > Changes in v2: > - Add Documentation/hwmon/tc654 > - Incorporate most of the review comments from Guenter. Additional error > handling is added. Unused/unnecessary code is removed. I decided not > to go down the regmap path yet. I may circle back to it when I look at > using regmap in the adm9240 driver. > > .../devicetree/bindings/i2c/trivial-devices.txt | 2 + > Documentation/hwmon/tc654 | 31 ++ > drivers/hwmon/Kconfig | 11 + > drivers/hwmon/Makefile | 1 + > drivers/hwmon/tc654.c | 514 +++++++++++++++++++++ > 5 files changed, 559 insertions(+) > create mode 100644 Documentation/hwmon/tc654 > create mode 100644 drivers/hwmon/tc654.c > > diff --git a/Documentation/devicetree/bindings/i2c/trivial-devices.txt b/Documentation/devicetree/bindings/i2c/trivial-devices.txt > index 1416c6a0d2cd..833fb9f133d3 100644 > --- a/Documentation/devicetree/bindings/i2c/trivial-devices.txt > +++ b/Documentation/devicetree/bindings/i2c/trivial-devices.txt > @@ -122,6 +122,8 @@ microchip,mcp4662-502 Microchip 8-bit Dual I2C Digital Potentiometer with NV Mem > microchip,mcp4662-103 Microchip 8-bit Dual I2C Digital Potentiometer with NV Memory (10k) > microchip,mcp4662-503 Microchip 8-bit Dual I2C Digital Potentiometer with NV Memory (50k) > microchip,mcp4662-104 Microchip 8-bit Dual I2C Digital Potentiometer with NV Memory (100k) > +microchip,tc654 PWM Fan Speed Controller With Fan Fault Detection > +microchip,tc655 PWM Fan Speed Controller With Fan Fault Detection > national,lm63 Temperature sensor with integrated fan control > national,lm75 I2C TEMP SENSOR > national,lm80 Serial Interface ACPI-Compatible Microprocessor System Hardware Monitor > diff --git a/Documentation/hwmon/tc654 b/Documentation/hwmon/tc654 > new file mode 100644 > index 000000000000..91a2843f5f98 > --- /dev/null > +++ b/Documentation/hwmon/tc654 > @@ -0,0 +1,31 @@ > +Kernel driver tc654 > +=================== > + > +Supported chips: > + * Microship TC654 and TC655 > + Prefix: 'tc654' > + Datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/20001734C.pdf > + > +Authors: > + Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx> > + Masahiko Iwamoto <iwamoto@xxxxxxxxxxxxxxxxxxxx> > + > +Description > +----------- > +This driver implements support for the Microchip TC654 and TC655. > + > +The TC654 uses the 2-wire interface compatible with the SMBUS 2.0 > +specification. The TC654 has two (2) inputs for measuring fan RPM and > +one (1) PWM output which can be used for fan control. > + > +Configuration Notes > +------------------- > +Ordinarily the pwm1_mode ABI is used for controlling the pwm output > +mode. However, for this chip the output is always pwm, and the > +pwm1_mode determines if the pwm output is controlled via the pwm1 value > +or via the Vin analog input. > + > + > +Setting pwm1_mode to 1 will cause the pwm output to be driven based on > +the pwm1 value. Setting pwm1_mode to 0 will cause the pwm output to be > +driven based on the Vin input. > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig > index 45cef3d2c75c..8681bc65cde5 100644 > --- a/drivers/hwmon/Kconfig > +++ b/drivers/hwmon/Kconfig > @@ -907,6 +907,17 @@ config SENSORS_MCP3021 > This driver can also be built as a module. If so, the module > will be called mcp3021. > > +config SENSORS_TC654 > + tristate "Microchip TC654/TC655 and compatibles" > + depends on I2C > + help > + If you say yes here you get support for TC654 and TC655. > + The TC654 and TC655 are PWM mode fan speed controllers with > + FanSense technology for use with brushless DC fans. > + > + This driver can also be built as a module. If so, the module > + will be called tc654. > + > config SENSORS_MENF21BMC_HWMON > tristate "MEN 14F021P00 BMC Hardware Monitoring" > depends on MFD_MENF21BMC > diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile > index aecf4ba17460..c651f0f1d047 100644 > --- a/drivers/hwmon/Makefile > +++ b/drivers/hwmon/Makefile > @@ -122,6 +122,7 @@ obj-$(CONFIG_SENSORS_MAX6697) += max6697.o > obj-$(CONFIG_SENSORS_MAX31790) += max31790.o > obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o > obj-$(CONFIG_SENSORS_MCP3021) += mcp3021.o > +obj-$(CONFIG_SENSORS_TC654) += tc654.o > obj-$(CONFIG_SENSORS_MENF21BMC_HWMON) += menf21bmc_hwmon.o > obj-$(CONFIG_SENSORS_NCT6683) += nct6683.o > obj-$(CONFIG_SENSORS_NCT6775) += nct6775.o > diff --git a/drivers/hwmon/tc654.c b/drivers/hwmon/tc654.c > new file mode 100644 > index 000000000000..04485f6d6983 > --- /dev/null > +++ b/drivers/hwmon/tc654.c > @@ -0,0 +1,514 @@ > +/* > + * tc654.c - Linux kernel modules for fan speed controller > + * > + * Copyright (C) 2016 Allied Telesis Labs NZ > + * > + * 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. > + */ > + > +#include <linux/bitops.h> > +#include <linux/err.h> > +#include <linux/hwmon.h> > +#include <linux/hwmon-sysfs.h> > +#include <linux/i2c.h> > +#include <linux/init.h> > +#include <linux/jiffies.h> > +#include <linux/module.h> > +#include <linux/mutex.h> > +#include <linux/slab.h> > +#include <linux/util_macros.h> > + > +enum tc654_regs { > + TC654_REG_RPM1 = 0x00, /* RPM Output 1 */ > + TC654_REG_RPM2 = 0x01, /* RPM Output 2 */ > + TC654_REG_FAN_FAULT1 = 0x02, /* Fan Fault 1 Threshold */ > + TC654_REG_FAN_FAULT2 = 0x03, /* Fan Fault 2 Threshold */ > + TC654_REG_CONFIG = 0x04, /* Configuration */ > + TC654_REG_STATUS = 0x05, /* Status */ > + TC654_REG_DUTY_CYCLE = 0x06, /* Fan Speed Duty Cycle */ > + TC654_REG_MFR_ID = 0x07, /* Manufacturer Identification */ > + TC654_REG_VER_ID = 0x08, /* Version Identification */ > +}; > + > +/* Macros to easily index the registers */ > +#define TC654_REG_RPM(idx) (TC654_REG_RPM1 + (idx)) > +#define TC654_REG_FAN_FAULT(idx) (TC654_REG_FAN_FAULT1 + (idx)) > + > +/* Config register bits */ > +#define TC654_REG_CONFIG_RES BIT(6) /* Resolution Selection */ > +#define TC654_REG_CONFIG_DUTYC BIT(5) /* Duty Cycle Control */ > +#define TC654_REG_CONFIG_SDM BIT(0) /* Shutdown Mode */ > + > +/* Status register bits */ > +#define TC654_REG_STATUS_F2F BIT(1) /* Fan 2 Fault */ > +#define TC654_REG_STATUS_F1F BIT(0) /* Fan 1 Fault */ > + > +/* RPM resolution for RPM Output registers */ > +#define TC654_HIGH_RPM_RESOLUTION 25 /* 25 RPM resolution */ > +#define TC654_LOW_RPM_RESOLUTION 50 /* 50 RPM resolution */ > + > +/* Convert to the fan fault RPM threshold from register value */ > +#define TC654_FAN_FAULT_FROM_REG(val) ((val) * 50) /* 50 RPM resolution */ > + > +/* Convert to register value from the fan fault RPM threshold */ > +#define TC654_FAN_FAULT_TO_REG(val) (((val) / 50) & 0xff) > + > +/* Register data is read (and cached) at most once per second. */ > +#define TC654_UPDATE_INTERVAL HZ > + > +struct tc654_data { > + struct i2c_client *client; > + > + /* update mutex */ > + struct mutex update_lock; > + > + /* tc654 register cache */ > + bool valid; > + unsigned long last_updated; /* in jiffies */ > + > + u8 rpm_output[2]; /* The fan RPM data for fans 1 and 2 is then > + * written to registers RPM1 and RPM2 > + */ > + u8 fan_fault[2]; /* The Fan Fault Threshold Registers are used to > + * set the fan fault threshold levels for fan 1 > + * and fan 2 > + */ > + u8 config; /* The Configuration Register is an 8-bit read/ > + * writable multi-function control register > + * 7: Fan Fault Clear > + * 1 = Clear Fan Fault > + * 0 = Normal Operation (default) > + * 6: Resolution Selection for RPM Output Registers > + * RPM Output Registers (RPM1 and RPM2) will be > + * set for > + * 1 = 25 RPM (9-bit) resolution > + * 0 = 50 RPM (8-bit) resolution (default) > + * 5: Duty Cycle Control Method > + * The V OUT duty cycle will be controlled via > + * 1 = the SMBus interface. > + * 0 = via the V IN analog input pin. (default) > + * 4,3: Fan 2 Pulses Per Rotation > + * 00 = 1 > + * 01 = 2 (default) > + * 10 = 4 > + * 11 = 8 > + * 2,1: Fan 1 Pulses Per Rotation > + * 00 = 1 > + * 01 = 2 (default) > + * 10 = 4 > + * 11 = 8 > + * 0: Shutdown Mode > + * 1 = Shutdown mode. > + * 0 = Normal operation. (default) > + */ > + u8 status; /* The Status register provides all the information > + * about what is going on within the TC654/TC655 > + * devices. > + * 7,6: Unimplemented, Read as '0' > + * 5: Over-Temperature Fault Condition > + * 1 = Over-Temperature condition has occurred > + * 0 = Normal operation. V IN is less than 2.6V > + * 4: RPM2 Counter Overflow > + * 1 = Fault condition > + * 0 = Normal operation > + * 3: RPM1 Counter Overflow > + * 1 = Fault condition > + * 0 = Normal operation > + * 2: V IN Input Status > + * 1 = V IN is open > + * 0 = Normal operation. voltage present at V IN > + * 1: Fan 2 Fault > + * 1 = Fault condition > + * 0 = Normal operation > + * 0: Fan 1 Fault > + * 1 = Fault condition > + * 0 = Normal operation > + */ > + u8 duty_cycle; /* The DUTY_CYCLE register is a 4-bit read/ > + * writable register used to control the duty > + * cycle of the V OUT output. > + */ > +}; > + > +/* helper to grab and cache data, at most one time per second */ > +static struct tc654_data *tc654_update_client(struct device *dev) > +{ > + struct tc654_data *data = dev_get_drvdata(dev); > + struct i2c_client *client = data->client; > + int ret = 0; > + > + mutex_lock(&data->update_lock); > + if (time_before(jiffies, data->last_updated + TC654_UPDATE_INTERVAL) && > + likely(data->valid)) > + goto out; > + > + ret = i2c_smbus_read_byte_data(client, TC654_REG_RPM(0)); > + if (ret < 0) > + goto out; > + data->rpm_output[0] = ret; > + > + ret = i2c_smbus_read_byte_data(client, TC654_REG_RPM(1)); > + if (ret < 0) > + goto out; > + data->rpm_output[1] = ret; > + > + ret = i2c_smbus_read_byte_data(client, TC654_REG_FAN_FAULT(0)); > + if (ret < 0) > + goto out; > + data->fan_fault[0] = ret; > + > + ret = i2c_smbus_read_byte_data(client, TC654_REG_FAN_FAULT(1)); > + if (ret < 0) > + goto out; > + data->fan_fault[1] = ret; > + > + ret = i2c_smbus_read_byte_data(client, TC654_REG_CONFIG); > + if (ret < 0) > + goto out; > + data->config = ret; > + > + ret = i2c_smbus_read_byte_data(client, TC654_REG_STATUS); > + if (ret < 0) > + goto out; > + data->status = ret; > + > + ret = i2c_smbus_read_byte_data(client, TC654_REG_DUTY_CYCLE); > + if (ret < 0) > + goto out; > + data->duty_cycle = ret & 0x0f; > + > + data->last_updated = jiffies; > + data->valid = true; > +out: > + mutex_unlock(&data->update_lock); > + > + if (ret < 0) /* upon error, encode it in return value */ > + data = ERR_PTR(ret); > + > + return data; > +} > + > +/* > + * sysfs attributes > + */ > + > +static ssize_t show_fan(struct device *dev, struct device_attribute *da, > + char *buf) > +{ > + int nr = to_sensor_dev_attr(da)->index; > + struct tc654_data *data = tc654_update_client(dev); > + int val; > + > + if (IS_ERR(data)) > + return PTR_ERR(data); > + > + if (data->config & TC654_REG_CONFIG_RES) > + val = data->rpm_output[nr] * TC654_HIGH_RPM_RESOLUTION; > + else > + val = data->rpm_output[nr] * TC654_LOW_RPM_RESOLUTION; > + > + return sprintf(buf, "%d\n", val); > +} > + > +static ssize_t show_fan_min(struct device *dev, struct device_attribute *da, > + char *buf) > +{ > + int nr = to_sensor_dev_attr(da)->index; > + struct tc654_data *data = tc654_update_client(dev); > + > + if (IS_ERR(data)) > + return PTR_ERR(data); > + > + return sprintf(buf, "%d\n", > + TC654_FAN_FAULT_FROM_REG(data->fan_fault[nr])); > +} > + > +static ssize_t set_fan_min(struct device *dev, struct device_attribute *da, > + const char *buf, size_t count) > +{ > + int nr = to_sensor_dev_attr(da)->index; > + struct tc654_data *data = dev_get_drvdata(dev); > + struct i2c_client *client = data->client; > + unsigned long val; > + int ret; > + > + if (kstrtoul(buf, 10, &val)) > + return -EINVAL; > + > + val = clamp_val(val, 0, 12750); > + > + mutex_lock(&data->update_lock); > + > + data->fan_fault[nr] = TC654_FAN_FAULT_TO_REG(val); > + ret = i2c_smbus_write_byte_data(client, TC654_REG_FAN_FAULT(nr), > + data->fan_fault[nr]); > + > + mutex_unlock(&data->update_lock); > + return ret < 0 ? ret : count; > +} > + > +static ssize_t show_fan_alarm(struct device *dev, struct device_attribute *da, > + char *buf) > +{ > + int nr = to_sensor_dev_attr(da)->index; > + struct tc654_data *data = tc654_update_client(dev); > + int val; > + > + if (IS_ERR(data)) > + return PTR_ERR(data); > + > + if (nr == 0) > + val = !!(data->status & TC654_REG_STATUS_F1F); > + else > + val = !!(data->status & TC654_REG_STATUS_F2F); > + > + return sprintf(buf, "%d\n", val); > +} > + > +static const u8 TC654_FAN_PULSE_SHIFT[] = { 1, 3 }; > + > +static ssize_t show_fan_pulses(struct device *dev, struct device_attribute *da, > + char *buf) > +{ > + int nr = to_sensor_dev_attr(da)->index; > + struct tc654_data *data = tc654_update_client(dev); > + u8 val; > + > + if (IS_ERR(data)) > + return PTR_ERR(data); > + > + val = BIT((data->config >> TC654_FAN_PULSE_SHIFT[nr]) & 0x03); > + return sprintf(buf, "%d\n", val); > +} > + > +static ssize_t set_fan_pulses(struct device *dev, struct device_attribute *da, > + const char *buf, size_t count) > +{ > + int nr = to_sensor_dev_attr(da)->index; > + struct tc654_data *data = dev_get_drvdata(dev); > + struct i2c_client *client = data->client; > + u8 config; > + unsigned long val; > + int ret; > + > + if (kstrtoul(buf, 10, &val)) > + return -EINVAL; > + > + switch (val) { > + case 1: > + config = 0; > + break; > + case 2: > + config = 1; > + break; > + case 4: > + config = 2; > + break; > + case 8: > + config = 3; > + break; > + default: > + return -EINVAL; > + } > + > + mutex_lock(&data->update_lock); > + > + data->config &= ~(0x03 << TC654_FAN_PULSE_SHIFT[nr]); > + data->config |= (config << TC654_FAN_PULSE_SHIFT[nr]); > + ret = i2c_smbus_write_byte_data(client, TC654_REG_CONFIG, data->config); > + > + mutex_unlock(&data->update_lock); > + return ret < 0 ? ret : count; > +} > + > +static ssize_t show_pwm_mode(struct device *dev, > + struct device_attribute *da, char *buf) > +{ > + struct tc654_data *data = tc654_update_client(dev); > + > + if (IS_ERR(data)) > + return PTR_ERR(data); > + > + return sprintf(buf, "%d\n", !!(data->config & TC654_REG_CONFIG_DUTYC)); > +} > + > +static ssize_t set_pwm_mode(struct device *dev, > + struct device_attribute *da, > + const char *buf, size_t count) > +{ > + struct tc654_data *data = dev_get_drvdata(dev); > + struct i2c_client *client = data->client; > + unsigned long val; > + int ret; > + > + if (kstrtoul(buf, 10, &val)) > + return -EINVAL; > + > + if (val != 0 && val != 1) > + return -EINVAL; > + > + mutex_lock(&data->update_lock); > + > + if (val) > + data->config |= TC654_REG_CONFIG_DUTYC; > + else > + data->config &= ~TC654_REG_CONFIG_DUTYC; > + > + ret = i2c_smbus_write_byte_data(client, TC654_REG_CONFIG, data->config); > + > + mutex_unlock(&data->update_lock); > + return ret < 0 ? ret : count; > +} > + > +static const int tc654_pwm_map[16] = { 77, 88, 102, 112, 124, 136, 148, 160, > + 172, 184, 196, 207, 219, 231, 243, 255}; > + > +static ssize_t show_pwm(struct device *dev, struct device_attribute *da, > + char *buf) > +{ > + struct tc654_data *data = tc654_update_client(dev); > + int pwm; > + > + if (IS_ERR(data)) > + return PTR_ERR(data); > + > + if (data->config & TC654_REG_CONFIG_SDM) > + pwm = 0; > + else > + pwm = tc654_pwm_map[data->duty_cycle]; > + > + return sprintf(buf, "%d\n", pwm); > +} > + > +static ssize_t set_pwm(struct device *dev, struct device_attribute *da, > + const char *buf, size_t count) > +{ > + struct tc654_data *data = dev_get_drvdata(dev); > + struct i2c_client *client = data->client; > + unsigned long val; > + int ret; > + > + if (kstrtoul(buf, 10, &val)) > + return -EINVAL; > + if (val > 255) > + return -EINVAL; > + > + mutex_lock(&data->update_lock); > + > + if (val == 0) > + data->config |= TC654_REG_CONFIG_SDM; > + else > + data->config &= ~TC654_REG_CONFIG_SDM; > + > + data->duty_cycle = find_closest(val, tc654_pwm_map, > + ARRAY_SIZE(tc654_pwm_map)); > + > + ret = i2c_smbus_write_byte_data(client, TC654_REG_CONFIG, data->config); > + if (ret < 0) > + goto out; > + > + ret = i2c_smbus_write_byte_data(client, TC654_REG_DUTY_CYCLE, > + data->duty_cycle); > + > +out: > + mutex_unlock(&data->update_lock); > + return ret < 0 ? ret : count; > +} > + > +static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, show_fan, NULL, 0); > +static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, show_fan, NULL, 1); > +static SENSOR_DEVICE_ATTR(fan1_min, S_IWUSR | S_IRUGO, show_fan_min, > + set_fan_min, 0); > +static SENSOR_DEVICE_ATTR(fan2_min, S_IWUSR | S_IRUGO, show_fan_min, > + set_fan_min, 1); > +static SENSOR_DEVICE_ATTR(fan1_alarm, S_IRUGO, show_fan_alarm, NULL, 0); > +static SENSOR_DEVICE_ATTR(fan2_alarm, S_IRUGO, show_fan_alarm, NULL, 1); > +static SENSOR_DEVICE_ATTR(fan1_pulses, S_IWUSR | S_IRUGO, show_fan_pulses, > + set_fan_pulses, 0); > +static SENSOR_DEVICE_ATTR(fan2_pulses, S_IWUSR | S_IRUGO, show_fan_pulses, > + set_fan_pulses, 1); > +static SENSOR_DEVICE_ATTR(pwm1_mode, S_IWUSR | S_IRUGO, > + show_pwm_mode, set_pwm_mode, 0); > +static SENSOR_DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, show_pwm, > + set_pwm, 0); > + > +/* Driver data */ > +static struct attribute *tc654_attrs[] = { > + &sensor_dev_attr_fan1_input.dev_attr.attr, > + &sensor_dev_attr_fan2_input.dev_attr.attr, > + &sensor_dev_attr_fan1_min.dev_attr.attr, > + &sensor_dev_attr_fan2_min.dev_attr.attr, > + &sensor_dev_attr_fan1_alarm.dev_attr.attr, > + &sensor_dev_attr_fan2_alarm.dev_attr.attr, > + &sensor_dev_attr_fan1_pulses.dev_attr.attr, > + &sensor_dev_attr_fan2_pulses.dev_attr.attr, > + &sensor_dev_attr_pwm1_mode.dev_attr.attr, > + &sensor_dev_attr_pwm1.dev_attr.attr, > + NULL > +}; > + > +ATTRIBUTE_GROUPS(tc654); > + > +/* > + * device probe and removal > + */ > + > +static int tc654_probe(struct i2c_client *client, > + const struct i2c_device_id *id) > +{ > + struct device *dev = &client->dev; > + struct tc654_data *data; > + struct device *hwmon_dev; > + int ret; > + > + if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA)) > + return -ENODEV; > + > + data = devm_kzalloc(dev, sizeof(struct tc654_data), GFP_KERNEL); > + if (!data) > + return -ENOMEM; > + > + data->client = client; > + mutex_init(&data->update_lock); > + > + ret = i2c_smbus_read_byte_data(client, TC654_REG_CONFIG); > + if (ret < 0) > + return ret; > + > + data->config = ret; > + > + hwmon_dev = > + devm_hwmon_device_register_with_groups(dev, client->name, data, > + tc654_groups); > + return PTR_ERR_OR_ZERO(hwmon_dev); > +} > + > +static const struct i2c_device_id tc654_id[] = { > + {"tc654", 0}, > + {"tc655", 0}, > + {} > +}; > + > +MODULE_DEVICE_TABLE(i2c, tc654_id); > + > +static struct i2c_driver tc654_driver = { > + .driver = { > + .name = "tc654", > + }, > + .probe = tc654_probe, > + .id_table = tc654_id, > +}; > + > +module_i2c_driver(tc654_driver); > + > +MODULE_AUTHOR("Allied Telesis Labs"); > +MODULE_DESCRIPTION("Microchip TC654/TC655 driver"); > +MODULE_LICENSE("GPL"); -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html