diff options
Diffstat (limited to 'drivers/iio/temperature')
| -rw-r--r-- | drivers/iio/temperature/max31856.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/drivers/iio/temperature/max31856.c b/drivers/iio/temperature/max31856.c index d97ba9ee1598..8457ca9ae326 100644 --- a/drivers/iio/temperature/max31856.c +++ b/drivers/iio/temperature/max31856.c @@ -12,6 +12,7 @@ #include <linux/spi/spi.h> #include <linux/iio/iio.h> #include <linux/iio/sysfs.h> +#include <linux/util_macros.h> #include <dt-bindings/iio/temperature/thermocouple.h> /* * The MSB of the register value determines whether the following byte will @@ -24,6 +25,8 @@ #define MAX31856_CR0_OCFAULT BIT(4) #define MAX31856_CR0_OCFAULT_MASK GENMASK(5, 4) #define MAX31856_CR0_FILTER_50HZ BIT(0) +#define MAX31856_AVERAGING_MASK GENMASK(6, 4) +#define MAX31856_AVERAGING_SHIFT 4 #define MAX31856_TC_TYPE_MASK GENMASK(3, 0) #define MAX31856_FAULT_OVUV BIT(1) #define MAX31856_FAULT_OPEN BIT(0) @@ -51,6 +54,8 @@ static const struct iio_chan_spec max31856_channels[] = { .type = IIO_TEMP, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), + .info_mask_shared_by_type = + BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO) }, { /* Cold Junction Temperature */ .type = IIO_TEMP, @@ -58,6 +63,8 @@ static const struct iio_chan_spec max31856_channels[] = { .modified = 1, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), + .info_mask_shared_by_type = + BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO) }, }; @@ -65,6 +72,7 @@ struct max31856_data { struct spi_device *spi; u32 thermocouple_type; bool filter_50hz; + int averaging; }; static int max31856_read(struct max31856_data *data, u8 reg, @@ -109,6 +117,10 @@ static int max31856_init(struct max31856_data *data) reg_cr1_val &= ~MAX31856_TC_TYPE_MASK; reg_cr1_val |= data->thermocouple_type; + + reg_cr1_val &= ~MAX31856_AVERAGING_MASK; + reg_cr1_val |= data->averaging << MAX31856_AVERAGING_SHIFT; + ret = max31856_write(data, MAX31856_CR1_REG, reg_cr1_val); if (ret) return ret; @@ -217,6 +229,9 @@ static int max31856_read_raw(struct iio_dev *indio_dev, return IIO_VAL_INT_PLUS_MICRO; } break; + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: + *val = 1 << data->averaging; + return IIO_VAL_INT; default: ret = -EINVAL; break; @@ -225,6 +240,33 @@ static int max31856_read_raw(struct iio_dev *indio_dev, return ret; } +static int max31856_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct max31856_data *data = iio_priv(indio_dev); + int msb; + + switch (mask) { + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: + if (val > 16 || val < 1) + return -EINVAL; + msb = fls(val) - 1; + /* Round up to next 2pow if needed */ + if (BIT(msb) < val) + msb++; + + data->averaging = msb; + max31856_init(data); + break; + + default: + return -EINVAL; + } + + return 0; +} + static ssize_t show_fault(struct device *dev, u8 faultbit, char *buf) { struct iio_dev *indio_dev = dev_to_iio_dev(dev); @@ -313,6 +355,7 @@ static const struct attribute_group max31856_group = { static const struct iio_info max31856_info = { .read_raw = max31856_read_raw, + .write_raw = max31856_write_raw, .attrs = &max31856_group, }; |