diff options
Diffstat (limited to 'drivers/iio/adc')
| -rw-r--r-- | drivers/iio/adc/ad7124.c | 69 |
1 files changed, 68 insertions, 1 deletions
diff --git a/drivers/iio/adc/ad7124.c b/drivers/iio/adc/ad7124.c index d9915dc71d1e..f0206d819fda 100644 --- a/drivers/iio/adc/ad7124.c +++ b/drivers/iio/adc/ad7124.c @@ -70,6 +70,11 @@ /* AD7124_FILTER_X */ #define AD7124_FILTER_FS_MSK GENMASK(10, 0) #define AD7124_FILTER_FS(x) FIELD_PREP(AD7124_FILTER_FS_MSK, x) +#define AD7124_FILTER_TYPE_MSK GENMASK(23, 21) +#define AD7124_FILTER_TYPE_SEL(x) FIELD_PREP(AD7124_FILTER_TYPE_MSK, x) + +#define AD7124_SINC3_FILTER 2 +#define AD7124_SINC4_FILTER 0 enum ad7124_ids { ID_AD7124_4, @@ -119,6 +124,7 @@ struct ad7124_channel_config { unsigned int vref_mv; unsigned int pga_bits; unsigned int odr; + unsigned int filter_type; }; struct ad7124_state { @@ -138,7 +144,8 @@ static const struct iio_chan_spec ad7124_channel_template = { .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET) | - BIT(IIO_CHAN_INFO_SAMP_FREQ), + BIT(IIO_CHAN_INFO_SAMP_FREQ) | + BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY), .scan_type = { .sign = 'u', .realbits = 24, @@ -281,6 +288,58 @@ static int ad7124_set_channel_gain(struct ad7124_state *st, return 0; } +static int ad7124_get_3db_filter_freq(struct ad7124_state *st, + unsigned int channel) +{ + unsigned int fadc; + + fadc = st->channel_config[channel].odr; + + switch (st->channel_config[channel].filter_type) { + case AD7124_SINC3_FILTER: + return DIV_ROUND_CLOSEST(fadc * 230, 1000); + case AD7124_SINC4_FILTER: + return DIV_ROUND_CLOSEST(fadc * 262, 1000); + default: + return -EINVAL; + } +} + +static int ad7124_set_3db_filter_freq(struct ad7124_state *st, + unsigned int channel, + unsigned int freq) +{ + unsigned int sinc4_3db_odr; + unsigned int sinc3_3db_odr; + unsigned int new_filter; + unsigned int new_odr; + + sinc4_3db_odr = DIV_ROUND_CLOSEST(freq * 1000, 230); + sinc3_3db_odr = DIV_ROUND_CLOSEST(freq * 1000, 262); + + if (sinc4_3db_odr > sinc3_3db_odr) { + new_filter = AD7124_SINC3_FILTER; + new_odr = sinc4_3db_odr; + } else { + new_filter = AD7124_SINC4_FILTER; + new_odr = sinc3_3db_odr; + } + + if (st->channel_config[channel].filter_type != new_filter) { + int ret; + + st->channel_config[channel].filter_type = new_filter; + ret = ad7124_spi_write_mask(st, AD7124_FILTER(channel), + AD7124_FILTER_TYPE_MSK, + AD7124_FILTER_TYPE_SEL(new_filter), + 3); + if (ret < 0) + return ret; + } + + return ad7124_set_channel_odr(st, channel, new_odr); +} + static int ad7124_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long info) @@ -323,6 +382,9 @@ static int ad7124_read_raw(struct iio_dev *indio_dev, *val = st->channel_config[chan->address].odr; return IIO_VAL_INT; + case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: + *val = ad7124_get_3db_filter_freq(st, chan->scan_index); + return IIO_VAL_INT; default: return -EINVAL; } @@ -355,6 +417,11 @@ static int ad7124_write_raw(struct iio_dev *indio_dev, gain = DIV_ROUND_CLOSEST(res, val2); return ad7124_set_channel_gain(st, chan->address, gain); + case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: + if (val2 != 0) + return -EINVAL; + + return ad7124_set_3db_filter_freq(st, chan->address, val); default: return -EINVAL; } |