From b17dc40155a973d0da68b54184dd9c237426c426 Mon Sep 17 00:00:00 2001 From: Marc Titinger Date: Fri, 11 Dec 2015 17:49:15 +0100 Subject: iio: ina2xx: re-instate a sysfs show/store for the shunt resistor value Different probe modules use different resistor values. The front-end application may read a probe ID (from eeprom) and set the shunt value accordingly. Signed-off-by: Marc Titinger Signed-off-by: Jonathan Cameron --- drivers/iio/adc/ina2xx-adc.c | 52 +++++++++++++++++++++++++++++++++++++++----- 1 file changed, 46 insertions(+), 6 deletions(-) (limited to 'drivers/iio') diff --git a/drivers/iio/adc/ina2xx-adc.c b/drivers/iio/adc/ina2xx-adc.c index ff31f5b49a41..dd4ff08d7b62 100644 --- a/drivers/iio/adc/ina2xx-adc.c +++ b/drivers/iio/adc/ina2xx-adc.c @@ -111,7 +111,7 @@ struct ina2xx_chip_info { struct task_struct *task; const struct ina2xx_config *config; struct mutex state_lock; - long rshunt; + unsigned int shunt_resistor; int avg; s64 prev_ns; /* track buffer capture time, check for underruns*/ int int_time_vbus; /* Bus voltage integration time uS */ @@ -349,6 +349,42 @@ static ssize_t ina2xx_allow_async_readout_store(struct device *dev, return len; } +static int set_shunt_resistor(struct ina2xx_chip_info *chip, unsigned int val) +{ + if (val <= 0 || val > chip->config->calibration_factor) + return -EINVAL; + + chip->shunt_resistor = val; + return 0; +} + +static ssize_t ina2xx_shunt_resistor_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev)); + + return sprintf(buf, "%d\n", chip->shunt_resistor); +} + +static ssize_t ina2xx_shunt_resistor_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev)); + unsigned long val; + int ret; + + ret = kstrtoul((const char *) buf, 10, &val); + if (ret) + return ret; + + ret = set_shunt_resistor(chip, val); + if (ret) + return ret; + + return len; +} #define INA2XX_CHAN(_type, _index, _address) { \ .type = (_type), \ @@ -545,9 +581,14 @@ static IIO_DEVICE_ATTR(in_allow_async_readout, S_IRUGO | S_IWUSR, ina2xx_allow_async_readout_show, ina2xx_allow_async_readout_store, 0); +static IIO_DEVICE_ATTR(in_shunt_resistor, S_IRUGO | S_IWUSR, + ina2xx_shunt_resistor_show, + ina2xx_shunt_resistor_store, 0); + static struct attribute *ina2xx_attributes[] = { &iio_dev_attr_in_allow_async_readout.dev_attr.attr, &iio_const_attr_integration_time_available.dev_attr.attr, + &iio_dev_attr_in_shunt_resistor.dev_attr.attr, NULL, }; @@ -579,7 +620,7 @@ static int ina2xx_init(struct ina2xx_chip_info *chip, unsigned int config) * to the user for now. */ regval = DIV_ROUND_CLOSEST(chip->config->calibration_factor, - chip->rshunt); + chip->shunt_resistor); return regmap_write(chip->regmap, INA2XX_CALIBRATION, regval); } @@ -612,10 +653,9 @@ static int ina2xx_probe(struct i2c_client *client, val = INA2XX_RSHUNT_DEFAULT; } - if (val <= 0 || val > chip->config->calibration_factor) - return -ENODEV; - - chip->rshunt = val; + ret = set_shunt_resistor(chip, val); + if (ret) + return ret; mutex_init(&chip->state_lock); -- cgit v1.2.3