diff options
Diffstat (limited to 'drivers/staging/iio/resolver/ad2s1210.c')
| -rw-r--r-- | drivers/staging/iio/resolver/ad2s1210.c | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/drivers/staging/iio/resolver/ad2s1210.c b/drivers/staging/iio/resolver/ad2s1210.c index 59c273a4b6a9..cf4018434447 100644 --- a/drivers/staging/iio/resolver/ad2s1210.c +++ b/drivers/staging/iio/resolver/ad2s1210.c @@ -314,6 +314,9 @@ static void ad2s1210_toggle_sample_line(struct ad2s1210_state *st) static int ad2s1210_reinit_excitation_frequency(struct ad2s1210_state *st, u16 fexcit) { + /* Map resolution to settle time in milliseconds. */ + static const int track_time_ms[] = { 10, 20, 25, 60 }; + unsigned int ignored; int ret; u8 fcw; @@ -329,7 +332,27 @@ static int ad2s1210_reinit_excitation_frequency(struct ad2s1210_state *st, * Software reset reinitializes the excitation frequency output. * It does not reset any of the configuration registers. */ - return regmap_write(st->regmap, AD2S1210_REG_SOFT_RESET, 0); + ret = regmap_write(st->regmap, AD2S1210_REG_SOFT_RESET, 0); + if (ret < 0) + return ret; + + /* + * Soft reset always triggers some faults due the change in the output + * signal so clear the faults too. We need to delay for some time + * (what datasheet calls t[track]) to allow things to settle before + * clearing the faults. + */ + msleep(track_time_ms[st->resolution] * 8192000 / st->clkin_hz); + + /* Reading the fault register clears the faults. */ + ret = regmap_read(st->regmap, AD2S1210_REG_FAULT, &ignored); + if (ret < 0) + return ret; + + /* Have to toggle sample line to get fault output pins to reset. */ + ad2s1210_toggle_sample_line(st); + + return 0; } static void ad2s1210_push_events(struct iio_dev *indio_dev, |