Peter Meerwald schrieb am 06.11.2014 17:54: >> Use iio: ms5637: Add Measurement Specialties MS5637 support instead of >> iio: (ms5637) Add Measurement Specialties MS5637 support for subject. >> >> If available please add a link to the datasheet here. > > some more comments below... Just one comment for now. > >> On Thu, Nov 6, 2014 at 11:46 AM, Markezana, William >> <William.Markezana@xxxxxxxxxxxxx> wrote: >>> Signed-off-by: Ludovic <ludovic.tancerel@xxxxxxxxxxxxxxxxx> >>> --- >>> drivers/iio/pressure/Kconfig | 10 + >>> drivers/iio/pressure/Makefile | 1 + >>> drivers/iio/pressure/ms5637.c | 488 +++++++++++++++++++++ >>> drivers/staging/iio/Documentation/pressure/ms5637 | 25 ++ > > don't add documentation to staging > >>> 4 files changed, 524 insertions(+) >>> create mode 100644 drivers/iio/pressure/ms5637.c >>> create mode 100644 drivers/staging/iio/Documentation/pressure/ms5637 >>> >>> diff --git a/drivers/iio/pressure/Kconfig b/drivers/iio/pressure/Kconfig >>> index ffac8ac..4ba9bd5 100644 >>> --- a/drivers/iio/pressure/Kconfig >>> +++ b/drivers/iio/pressure/Kconfig >>> @@ -41,6 +41,16 @@ config MPL3115 >>> To compile this driver as a module, choose M here: the module >>> will be called mpl3115. >>> >>> +config MS5637 >>> + tristate "MS5637 pressure & temperature sensor" >>> + depends on I2C >>> + help >>> + If you say yes here you get support for the Measurement Specialties >>> + MS5637 pressure and temperature sensor. >>> + >>> + This driver can also be built as a module. If so, the module will >>> + be called ms5637. >>> + >>> config IIO_ST_PRESS >>> tristate "STMicroelectronics pressure sensor Driver" >>> depends on (I2C || SPI_MASTER) && SYSFS >>> diff --git a/drivers/iio/pressure/Makefile b/drivers/iio/pressure/Makefile >>> index c53d250..50fe66e 100644 >>> --- a/drivers/iio/pressure/Makefile >>> +++ b/drivers/iio/pressure/Makefile >>> @@ -6,6 +6,7 @@ >>> obj-$(CONFIG_HID_SENSOR_PRESS) += hid-sensor-press.o >>> obj-$(CONFIG_MPL115) += mpl115.o >>> obj-$(CONFIG_MPL3115) += mpl3115.o >>> +obj-$(CONFIG_MS5637) += ms5637.o >>> obj-$(CONFIG_IIO_ST_PRESS) += st_pressure.o >>> st_pressure-y := st_pressure_core.o >>> st_pressure-$(CONFIG_IIO_BUFFER) += st_pressure_buffer.o >>> diff --git a/drivers/iio/pressure/ms5637.c b/drivers/iio/pressure/ms5637.c >>> new file mode 100644 >>> index 0000000..ea74636 >>> --- /dev/null >>> +++ b/drivers/iio/pressure/ms5637.c >>> @@ -0,0 +1,488 @@ >>> +/* >>> + * ms5637.c - Support for Measurement Specialties MS5637 temperature sensor > > pressure & temperature > >>> + * >>> + * Copyright (c) 2014 Measurement Specialties >>> + * >>> + * Licensed under the GPL-2. >>> + * >>> + * (7-bit I2C slave address 0x77) >>> + * >>> + */ >>> + >>> +#include <linux/init.h> >>> +#include <linux/device.h> >>> +#include <linux/kernel.h> >>> +#include <linux/stat.h> >>> +#include <linux/module.h> >>> +#include <linux/i2c.h> >>> +#include <linux/iio/iio.h> >>> +#include <linux/iio/sysfs.h> >>> +#include <linux/jiffies.h> >>> +#include <linux/delay.h> >>> +#include <linux/mutex.h> >>> + >>> +/* MS5637 Commands */ >>> +#define MS5637_RESET (0x1E) >>> +#define MS5637_TEMPERATURE_CONVERSION_START (0x50) >>> +#define MS5637_PRESSURE_CONVERSION_START (0x40) >>> +#define MS5637_ADC_READ (0x00) >>> +#define MS5637_PROM_READ (0xA0) >>> +#define MS5637_PROM_ELEMENTS_NB (7) >> >> I would prefer to remove "()" around hexa/decimal values. >> >>> + >>> +#define ATTR_RESET 0 >>> +#define ATTR_RESOLUTION 1 > > MS5637_ prefix please > >>> + >>> +static const u16 conversion_time[] = { 1000, 2000, 3000, 5000, 9000, 17000 }; > > ms5637_ prefix please > >>> + >>> +struct ms5637_dev { >>> + struct i2c_client *client; >>> + struct mutex lock; /* mutex protecting this data structure */ >>> + u16 calibration_coeffs[MS5637_PROM_ELEMENTS_NB]; >>> + bool got_calibration_words; >>> + unsigned long last_update; >>> + bool valid; >>> + int temperature; >>> + unsigned int pressure; >>> + u8 resolution_index; >>> +}; >>> + >>> +static int ms5637_get_calibration_coeffs(struct ms5637_dev *dev_data, >>> + unsigned char index, u16 *word) >>> +{ >>> + int ret = 0; >>> + >>> + ret = i2c_smbus_read_word_swapped(dev_data->client, >>> + MS5637_PROM_READ + (index << 1)); >>> + if (ret < 0) >>> + return ret; >>> + *word = (u16) ret & 0xFFFF; >>> + return 0; >>> +} >>> + >>> +static bool ms5637_crc_check(u16 *n_prom, u8 crc) >>> +{ >>> + u8 cnt, n_bit; > > cnt should be unsigned int, it's just a counter should have the CPUs > native size > >>> + u16 n_rem, crc_read; >>> + >>> + n_rem = 0x00; > > should be 0 or 0x0000 as n_rem is u16 > >>> + crc_read = n_prom[0]; >>> + n_prom[MS5637_PROM_ELEMENTS_NB] = 0; >>> + n_prom[0] = (0x0FFF & (n_prom[0])); /* Clear the CRC byte */ > > remove extra parenthesis Actually, it should be as simple as this: n_prom[0] &= 0x0FFF; > >>> + >>> + for (cnt = 0; cnt < (MS5637_PROM_ELEMENTS_NB + 1) * 2; cnt++) { >>> + if (cnt % 2 == 1) >>> + n_rem ^= n_prom[cnt >> 1] & 0x00FF; >>> + else >>> + n_rem ^= n_prom[cnt >> 1] >> 8; >>> + >>> + for (n_bit = 8; n_bit > 0; n_bit--) { >>> + if (n_rem & 0x8000) >>> + n_rem = (n_rem << 1) ^ 0x3000; >>> + else >>> + n_rem <<= 1; >>> + } >>> + } >>> + n_rem >>= 12; >>> + n_prom[0] = crc_read; >>> + return (n_rem == crc); >>> +} >>> + >>> +static int ms5637_fill_calibration_coeffs(struct ms5637_dev *dev_data) >>> +{ >>> + int i, ret = 0; >>> + >>> + for (i = 0; i < MS5637_PROM_ELEMENTS_NB; i++) { >>> + ret = ms5637_get_calibration_coeffs(dev_data, i, >>> + &dev_data->calibration_coeffs >>> + [i]); > > linebreak looks weird before [i] > >>> + >>> + dev_dbg(&dev_data->client->dev, "Coeff %d : %d", i, >>> + dev_data->calibration_coeffs[i]); > > debug output should be after validity check > >>> + >>> + if (ret < 0) { >>> + dev_err(&dev_data->client->dev, >>> + "unable to get calibration coefficients at address %d\n", > > Unable probably (uppercase all all other messages > >>> + i + 1); >>> + return ret; >>> + } >>> + } >>> + >>> + if (!ms5637_crc_check(dev_data->calibration_coeffs, >>> + (dev_data-> >>> + calibration_coeffs[0] & 0xF000) >> 12)) { >>> + dev_err(&dev_data->client->dev, >>> + "Calibration coefficients crc check error\n"); >>> + return -1; >>> + } >>> + >>> + return 0; >>> +} >>> + >>> +static int ms5637_read_adc_value(struct ms5637_dev *dev_data, u32 *adc_value) >>> +{ >>> + int ret = 0; > > no need to initialize ret > >>> + u8 buf[3]; >>> + >>> + ret = >>> + i2c_smbus_read_i2c_block_data(dev_data->client, MS5637_ADC_READ, 3, >>> + buf); >>> + if (ret < 0) >>> + return ret; >>> + dev_dbg(&dev_data->client->dev, "ADC raw value : %x %x %x\n", buf[0], >>> + buf[1], buf[2]); >>> + *adc_value = (buf[0] << 16) + (buf[1] << 8) + buf[0]; >>> + return 0; >>> +} >>> + >>> +static int ms5637_conversion_and_read_adc(struct ms5637_dev *dev_data, >>> + u32 *t_adc, u32 *p_adc) >>> +{ >>> + int ret; >>> + >>> + /* Trigger Temperature conversion */ >>> + ret = i2c_smbus_write_byte(dev_data->client, >>> + MS5637_TEMPERATURE_CONVERSION_START >>> + + dev_data->resolution_index * 2); >>> + if (ret < 0) >>> + return ret; >>> + usleep_range(conversion_time[dev_data->resolution_index], >>> + conversion_time[dev_data->resolution_index]+3000); >>> + /* Retrieve ADC value */ >>> + ret = ms5637_read_adc_value(dev_data, t_adc); >>> + >> No check for ret here? If this is not needed then you can remove >> the above assignment. >> >>> + /* Trigger Pressure conversion */ >>> + ret = i2c_smbus_write_byte(dev_data->client, >>> + MS5637_PRESSURE_CONVERSION_START >>> + + dev_data->resolution_index * 2); >>> + if (ret < 0) >>> + return ret; >>> + usleep_range(conversion_time[dev_data->resolution_index], >>> + conversion_time[dev_data->resolution_index]+3000); >>> + /* Retrieve ADC value */ >>> + ret = ms5637_read_adc_value(dev_data, p_adc); >>> + >> No new line here. >>> + if (ret < 0) >>> + return ret; >>> + return 0; >>> +} >>> + >>> +static int ms5637_read_temperature_and_pressure(struct ms5637_dev *dev_data) >>> +{ >>> + int ret = 0; >>> + u32 t_adc, p_adc; >>> + s32 dt, temp; >>> + s64 off, sens, t2, off2, sens2; >>> + >>> + mutex_lock(&dev_data->lock); >>> + >>> + if (time_after(jiffies, dev_data->last_update + HZ / 2) || >>> + !dev_data->valid) { >>> + if (!dev_data->got_calibration_words) { >>> + ret = ms5637_fill_calibration_coeffs(dev_data); >>> + if (ret < 0) >>> + goto out; >>> + >>> + dev_data->got_calibration_words = true; >>> + } >>> + >>> + ret = ms5637_conversion_and_read_adc(dev_data, &t_adc, &p_adc); >>> + > remove blank line > >>> + if (ret < 0) { >>> + dev_data->got_calibration_words = false; >>> + dev_err(&dev_data->client->dev, >>> + "unable to make sensor adc conversion\n"); >>> + goto out; >>> + } >>> + >>> + dt = (s32) t_adc - (dev_data->calibration_coeffs[5] << 8); >>> + >>> + /* Actual temperature = 2000 + dT * TEMPSENS */ >>> + temp = >>> + 2000 + (((s64) dt * dev_data->calibration_coeffs[6]) >> 23); >>> + >>> + /* Second order temperature compensation */ >>> + if (temp < 2000) { >>> + s64 tmp = (s64) temp - 2000; >>> + >>> + t2 = (3 * ((s64) dt * (s64) dt)) >> 33; >>> + off2 = (61 * tmp * tmp) >> 4; >>> + sens2 = (29 * tmp * tmp) >> 4; >>> + >>> + if (temp < -1500) { >>> + s64 tmp = (s64) temp + 1500; >>> + >>> + off2 += 17 * tmp * tmp; >>> + sens2 += 9 * tmp * tmp; >>> + } >>> + } else { >>> + t2 = (5 * ((s64) dt * (s64) dt)) >> 38; >>> + off2 = 0; >>> + sens2 = 0; >>> + } >>> + >>> + /* OFF = OFF_T1 + TCO * dT */ >>> + off = (((s64) dev_data->calibration_coeffs[2]) << 17) >>> + + >>> + ((((s64) dev_data->calibration_coeffs[4]) * (s64) dt) >> 6); >>> + off -= off2; >>> + >>> + /* Sensitivity at actual temperature = SENS_T1 + TCS * dT */ >>> + sens = (((s64) dev_data->calibration_coeffs[1]) << 16) >>> + + (((s64) dev_data->calibration_coeffs[3] * dt) >> 7); >>> + sens -= sens2; >>> + >>> + /* Temperature compensated pressure = D1 * SENS - OFF */ >>> + dev_data->temperature = (temp - t2) * 10; >>> + dev_data->pressure = (u32) (((((s64) p_adc * sens) >> 21) >>> + - off) >> 15) / 100; >>> + >>> + dev_data->last_update = jiffies; >>> + dev_data->valid = true; >>> + } >>> + out: >>> + mutex_unlock(&dev_data->lock); >>> + >>> + return ret >= 0 ? 0 : ret; >>> +} >>> + >>> +static int ms5637_read_raw(struct iio_dev *indio_dev, >>> + struct iio_chan_spec const *channel, int *val, >>> + int *val2, long mask) >>> +{ >>> + int ret; >>> + struct ms5637_dev *dev_data = iio_priv(indio_dev); >>> + >>> + switch (mask) { >>> + case IIO_CHAN_INFO_PROCESSED: >>> + switch (channel->type) { >>> + case IIO_TEMP: /* in 0.001 °C */ >>> + ret = ms5637_read_temperature_and_pressure(dev_data); >>> + if (ret) >>> + goto t_err; >>> + *val = dev_data->temperature; >>> + break; >>> + case IIO_PRESSURE: /* in mB */ > > IIO wants kilopoascal > >>> + ret = ms5637_read_temperature_and_pressure(dev_data); >>> + if (ret) >>> + goto p_err; >>> + *val = dev_data->pressure; >>> + break; >>> + default: >>> + return -EINVAL; >>> + } >>> + ret = IIO_VAL_INT; >>> + break; >>> + default: >>> + return -EINVAL; >>> + } >>> + >>> + return ret; > > should simplify control flow a bit, just return instead of breaking, > jumping > > is it really necesary to have two different error messages? > could just code the call to ms5637_read_temperature_and_pressure() once > >>> + t_err: >>> + dev_err(&indio_dev->dev, "Temperature read error\n"); >>> + return ret; >>> + p_err: >>> + dev_err(&indio_dev->dev, "Pressure read error\n"); >>> + return ret; >>> +} >>> + >>> +static const struct iio_chan_spec ms5637_channels[] = { >>> + { >>> + .type = IIO_TEMP, >>> + .output = 1, >>> + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), >>> + .scan_index = 0, >>> + }, >>> + { >>> + .type = IIO_PRESSURE, >>> + .output = 1, > > output is for output channels, I guess the ms5637 cannot change the > weather :) > >>> + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), >>> + .scan_index = 0, > > no need set the scan_index > >>> + } >>> +}; >>> + >>> +static ssize_t ms5637_read_attr(struct device *dev, >>> + struct device_attribute *attr, char *buf) >>> +{ >>> + struct iio_dev *indio_dev = dev_to_iio_dev(dev); >>> + struct ms5637_dev *dev_data = iio_priv(indio_dev); >>> + struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); >>> + int ret = 0; >>> + >>> + switch (this_attr->address) { >>> + case ATTR_RESET: >>> + ret = sprintf(buf, "0\n"); >>> + break; >>> + case ATTR_RESOLUTION: > > uhuh, private ABI > maybe this could be modelled by IIO's integration time? > >>> + ret = sprintf(buf, "%d\n", dev_data->resolution_index + 8); >>> + break; >>> + default: >>> + return -EINVAL; >>> + } >>> + >>> + return ret; >>> +} >>> + >>> +static ssize_t ms5637_write_attr(struct device *dev, >>> + struct device_attribute *attr, >>> + const char *buf, size_t len) >>> +{ >>> + struct iio_dev *indio_dev = dev_to_iio_dev(dev); >>> + struct ms5637_dev *dev_data = iio_priv(indio_dev); >>> + struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); >>> + u8 val; >>> + int ret; >>> + >>> + ret = kstrtou8(buf, 10, &val); >>> + if (ret) >>> + return ret; >>> + >>> + mutex_lock(&dev_data->lock); >>> + switch (this_attr->address) { >>> + case ATTR_RESET: >>> + if (val != 1) >>> + goto einval; >>> + >>> + ret = i2c_smbus_write_byte(dev_data->client, MS5637_RESET); >>> + if (ret < 0) >>> + goto out; >>> + usleep_range(3000, 6000); >>> + >>> + break; >>> + case ATTR_RESOLUTION: >>> + if ((val < 8) || (val > 13)) >>> + goto einval; >>> + dev_data->resolution_index = val - 8; >>> + break; >>> + default: >>> + goto einval; >>> + } >>> + >>> + dev_data->valid = false; >>> + goto out; >>> + einval: >>> + ret = -EINVAL; >>> + out: >>> + mutex_unlock(&dev_data->lock); >>> + >>> + return ret ? ret : len; >>> +} >>> + >>> +static IIO_DEVICE_ATTR(in_reset, >>> + S_IRUGO | S_IWUSR, >>> + ms5637_read_attr, ms5637_write_attr, ATTR_RESET); >>> +static IIO_DEVICE_ATTR(in_resolution, >>> + S_IRUGO | S_IWUSR, >>> + ms5637_read_attr, ms5637_write_attr, ATTR_RESOLUTION); >>> +static IIO_CONST_ATTR(resolution_available, "8 9 10 11 12 13"); >>> + >>> +static struct attribute *ms5637_attributes[] = { >>> + &iio_dev_attr_in_reset.dev_attr.attr, >>> + &iio_dev_attr_in_resolution.dev_attr.attr, >>> + &iio_const_attr_resolution_available.dev_attr.attr, >>> + NULL, >>> +}; >>> + >>> +static const struct attribute_group ms5637_attribute_group = { >>> + .attrs = ms5637_attributes, >>> +}; >>> + >>> +static const struct iio_info ms5637_info = { >>> + .read_raw = ms5637_read_raw, >>> + .attrs = &ms5637_attribute_group, >>> + .driver_module = THIS_MODULE, >>> +}; >>> + >>> +static int ms5637_probe(struct i2c_client *client, >>> + const struct i2c_device_id *id) >>> +{ >>> + struct ms5637_dev *dev_data; >>> + struct iio_dev *indio_dev; >>> + int ret; >>> + >>> + if (!i2c_check_functionality(client->adapter, >>> + I2C_FUNC_SMBUS_READ_WORD_DATA)) { >>> + dev_err(&client->dev, >>> + "adapter does not support SMBus read word transactions\n"); >>> + return -ENODEV; >>> + } >>> + >>> + if (!i2c_check_functionality(client->adapter, >>> + I2C_FUNC_SMBUS_WRITE_BYTE)) { >>> + dev_err(&client->dev, >>> + "adapter does not support SMBus write byte transactions\n"); >>> + return -ENODEV; >>> + } >>> + >>> + if (!i2c_check_functionality(client->adapter, >>> + I2C_FUNC_SMBUS_READ_I2C_BLOCK)) { >>> + dev_err(&client->dev, >>> + "adapter does not support SMBus read block transactions\n"); >>> + return -ENODEV; >>> + } >>> + >>> + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*dev_data)); >>> + if (!indio_dev) >>> + return -ENOMEM; >>> + >>> + dev_data = iio_priv(indio_dev); >>> + dev_data->client = client; >>> + mutex_init(&dev_data->lock); >>> + >>> + indio_dev->info = &ms5637_info; >>> + indio_dev->name = id->name; >>> + indio_dev->dev.parent = &client->dev; >>> + indio_dev->modes = INDIO_DIRECT_MODE; >>> + indio_dev->channels = ms5637_channels; >>> + indio_dev->num_channels = ARRAY_SIZE(ms5637_channels); >>> + >>> + i2c_set_clientdata(client, indio_dev); >>> + ret = iio_device_register(indio_dev); >>> + if (ret < 0) >>> + return ret; >>> + >>> + ret = i2c_smbus_write_byte(client, MS5637_RESET); > > I'd rather do this before iio_device_register() -- what happens when it > fails? there is no unregister() > >>> + if (ret < 0) >>> + return ret; >>> + usleep_range(3000, 6000); >>> + >>> + ret = ms5637_fill_calibration_coeffs(dev_data); >>> + if (ret == 0) >>> + dev_data->got_calibration_words = true; >>> + >>> + if (ret < 0) >>> + return ret; >>> + >>> + dev_dbg(&client->dev, "Driver initialization done"); >>> + return 0; >>> +} >>> + >>> +static int ms5637_remove(struct i2c_client *client) >>> +{ >>> + struct iio_dev *indio_dev = i2c_get_clientdata(client); >>> + >>> + iio_device_unregister(indio_dev); >>> + >>> + return 0; >>> +} >>> + >>> +static const struct i2c_device_id ms5637_id[] = { >>> + {"ms5637", 0}, >>> + {} >>> +}; >>> + >>> +static struct i2c_driver ms5637_driver = { >>> + .probe = ms5637_probe, >>> + .remove = ms5637_remove, >>> + .id_table = ms5637_id, >>> + .driver = { >>> + .name = "ms5637", >>> + .owner = THIS_MODULE, >>> + }, >>> +}; >>> + >>> +module_i2c_driver(ms5637_driver); >>> + >>> +MODULE_LICENSE("GPL"); >>> +MODULE_DESCRIPTION("Measurement Specialties MS5637 temperature driver"); >>> +MODULE_AUTHOR("William Markezana <william.markezana@xxxxxxxxxxxxx>"); >>> +MODULE_AUTHOR("Ludovic Tancerel <ludovic.tancerel@xxxxxxxxxxxxxxxxx>"); >>> diff --git a/drivers/staging/iio/Documentation/pressure/ms5637 b/drivers/staging/iio/Documentation/pressure/ms5637 >>> new file mode 100644 >>> index 0000000..d0d64f3 >>> --- /dev/null >>> +++ b/drivers/staging/iio/Documentation/pressure/ms5637 >>> @@ -0,0 +1,25 @@ >>> +Kernel driver ms5637 >>> +==================== >>> + >>> +Supported chips: >>> + * Measurement Specialties MS5637 >>> + Prefix: 'ms5637' >>> + Addresses scanned: I2C 0x76 > > 0x77 is claimed at the top of ms5637.c > >>> + Datasheet: Available for download on meas-spec.com >>> + >>> +Authors: >>> + William Markezana (Meas-Spec) <william.markezana@xxxxxxxxxxxxx> >>> + Ludovic Tancerel <ludovic.tancerel@xxxxxxxxxxxxxxxxx> >>> + >>> +Description >>> +----------- >>> + >>> +The MS5637 is a single chip pressure & temperature sensor. >>> +The driver returns a milli-bar pressure value and a milli-degre celius value using the iio framework > > degree; the information so far is redundant > >>> + >>> +Via the iio sysfs interface, there are several attributes available. >>> +in_reset - Reset ms5637 device by writing a 1 in it. >>> +in_resolution - Set the number of bits for ADC resolution. >>> +out_pressure_input - Current pressure from ms5637 sensor (milli-bar) >>> +out_temp_input - Current temperature from htu21 sensor (milli-°C value) >>> +resolution_available - List of resolutions supported > > in_, not out_ > > regular IIO channels (integration time?) could/should be used > > I don't know about reset, needed? > > private ABI should go to documentation/ABI/testing/sysfs-bus-iio-* > >>> -- >>> 1.7.9.5 >>> >>> -- >>> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >>> the body of a message to majordomo@xxxxxxxxxxxxxxx >>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>> Please read the FAQ at http://www.tux.org/lkml/ >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> Please read the FAQ at http://www.tux.org/lkml/ >> > -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html