This adds an implementation of IIO_CHAN_INFO_SCALE to the ad2s1210 resolver driver. This allows userspace to get the scale factor for the raw values. Signed-off-by: David Lechner <dlechner@xxxxxxxxxxxx> --- drivers/staging/iio/resolver/ad2s1210.c | 107 ++++++++++++++++-------- 1 file changed, 72 insertions(+), 35 deletions(-) diff --git a/drivers/staging/iio/resolver/ad2s1210.c b/drivers/staging/iio/resolver/ad2s1210.c index 985b8fecd65a..95d43b241a75 100644 --- a/drivers/staging/iio/resolver/ad2s1210.c +++ b/drivers/staging/iio/resolver/ad2s1210.c @@ -458,56 +458,91 @@ static ssize_t ad2s1210_store_reg(struct device *dev, return ret < 0 ? ret : len; } +static const int ad2s1210_velocity_scale[] = { + 17089132, /* 8.192MHz / (2*pi * 2500 / 2^15) */ + 42722830, /* 8.192MHz / (2*pi * 1000 / 2^15) */ + 85445659, /* 8.192MHz / (2*pi * 500 / 2^15) */ + 341782638, /* 8.192MHz / (2*pi * 125 / 2^15) */ +}; + static int ad2s1210_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, - long m) + long mask) { struct ad2s1210_state *st = iio_priv(indio_dev); int ret = 0; - mutex_lock(&st->lock); - gpiod_set_value(st->gpios[AD2S1210_SAMPLE], 0); - /* delay (6 * tck + 20) nano seconds */ - udelay(1); + switch (mask) { + case IIO_CHAN_INFO_RAW: + mutex_lock(&st->lock); + gpiod_set_value(st->gpios[AD2S1210_SAMPLE], 0); + /* delay (6 * tck + 20) nano seconds */ + udelay(1); + + switch (chan->type) { + case IIO_ANGL: + ad2s1210_set_mode(MOD_POS, st); + break; + case IIO_ANGL_VEL: + ad2s1210_set_mode(MOD_VEL, st); + break; + default: + ret = -EINVAL; + break; + } + if (ret < 0) + goto error_info_raw; + ret = spi_read(st->sdev, st->rx, 2); + if (ret < 0) + goto error_info_raw; + + switch (chan->type) { + case IIO_ANGL: + *val = be16_to_cpup((__be16 *)st->rx); + ret = IIO_VAL_INT; + break; + case IIO_ANGL_VEL: + *val = (s16)be16_to_cpup((__be16 *)st->rx); + ret = IIO_VAL_INT; + break; + default: + ret = -EINVAL; + break; + } - switch (chan->type) { - case IIO_ANGL: - ad2s1210_set_mode(MOD_POS, st); - break; - case IIO_ANGL_VEL: - ad2s1210_set_mode(MOD_VEL, st); - break; - default: - ret = -EINVAL; +error_info_raw: + gpiod_set_value(st->gpios[AD2S1210_SAMPLE], 1); + /* delay (2 * tck + 20) nano seconds */ + udelay(1); + mutex_unlock(&st->lock); break; - } - if (ret < 0) - goto error_ret; - ret = spi_read(st->sdev, st->rx, 2); - if (ret < 0) - goto error_ret; - switch (chan->type) { - case IIO_ANGL: - *val = be16_to_cpup((__be16 *)st->rx); - ret = IIO_VAL_INT; - break; - case IIO_ANGL_VEL: - *val = (s16)be16_to_cpup((__be16 *)st->rx); - ret = IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + switch (chan->type) { + case IIO_ANGL: + /* approx 0.3 arc min converted to radians */ + *val = 0; + *val2 = 95874; + ret = IIO_VAL_INT_PLUS_NANO; + break; + case IIO_ANGL_VEL: + *val = st->fclkin; + *val2 = ad2s1210_velocity_scale[st->resolution]; + ret = IIO_VAL_FRACTIONAL; + break; + default: + ret = -EINVAL; + break; + } break; + default: ret = -EINVAL; break; } -error_ret: - gpiod_set_value(st->gpios[AD2S1210_SAMPLE], 1); - /* delay (2 * tck + 20) nano seconds */ - udelay(1); - mutex_unlock(&st->lock); return ret; } @@ -549,12 +584,14 @@ static const struct iio_chan_spec ad2s1210_channels[] = { .type = IIO_ANGL, .indexed = 1, .channel = 0, - .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), }, { .type = IIO_ANGL_VEL, .indexed = 1, .channel = 0, - .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), } }; -- 2.34.1