diff options
| author | David Lechner <dlechner@baylibre.com> | 2023-09-29 20:23:12 +0300 |
|---|---|---|
| committer | Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2023-09-30 17:40:43 +0300 |
| commit | 1b6eba71cae261d504d5826897a22a9a45f200d2 (patch) | |
| tree | ba150bfe8f82cc26c0474b7bd134191cffbde003 /drivers/staging/iio | |
| parent | acbfaee17014811d96d9094ce2fb723384dfc009 (diff) | |
| download | linux-1b6eba71cae261d504d5826897a22a9a45f200d2.tar.xz | |
staging: iio: resolver: ad2s1210: always use 16-bit value for raw read
This removes the special handling for resolutions lower than 16 bits.
This will allow us to use a fixed scale independent of the resolution.
A new sample field is added to store the raw data instead of reusing
the config mode rx buffer so that we don't have to do a cast or worry
about unaligned access.
Also, for the record, according to the datasheet, the logic for the
special handling based on hysteresis that was removed was incorrect.
Signed-off-by: David Lechner <dlechner@baylibre.com>
Link: https://lore.kernel.org/r/20230929-ad2s1210-mainline-v3-7-fa4364281745@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'drivers/staging/iio')
| -rw-r--r-- | drivers/staging/iio/resolver/ad2s1210.c | 24 |
1 files changed, 8 insertions, 16 deletions
diff --git a/drivers/staging/iio/resolver/ad2s1210.c b/drivers/staging/iio/resolver/ad2s1210.c index 832f86bf15e5..f9774dff2df4 100644 --- a/drivers/staging/iio/resolver/ad2s1210.c +++ b/drivers/staging/iio/resolver/ad2s1210.c @@ -95,7 +95,11 @@ struct ad2s1210_state { bool hysteresis; u8 resolution; enum ad2s1210_mode mode; - u8 rx[2] __aligned(IIO_DMA_MINALIGN); + /** For reading raw sample value via SPI. */ + __be16 sample __aligned(IIO_DMA_MINALIGN); + /** SPI transmit buffer. */ + u8 rx[2]; + /** SPI receive buffer. */ u8 tx[2]; }; @@ -464,10 +468,7 @@ static int ad2s1210_read_raw(struct iio_dev *indio_dev, long m) { struct ad2s1210_state *st = iio_priv(indio_dev); - u16 negative; int ret = 0; - u16 pos; - s16 vel; mutex_lock(&st->lock); gpiod_set_value(st->gpios[AD2S1210_SAMPLE], 0); @@ -487,26 +488,17 @@ static int ad2s1210_read_raw(struct iio_dev *indio_dev, } if (ret < 0) goto error_ret; - ret = spi_read(st->sdev, st->rx, 2); + ret = spi_read(st->sdev, &st->sample, 2); if (ret < 0) goto error_ret; switch (chan->type) { case IIO_ANGL: - pos = be16_to_cpup((__be16 *)st->rx); - if (st->hysteresis) - pos >>= 16 - st->resolution; - *val = pos; + *val = be16_to_cpu(st->sample); ret = IIO_VAL_INT; break; case IIO_ANGL_VEL: - vel = be16_to_cpup((__be16 *)st->rx); - vel >>= 16 - st->resolution; - if (vel & 0x8000) { - negative = (0xffff >> st->resolution) << st->resolution; - vel |= negative; - } - *val = vel; + *val = (s16)be16_to_cpu(st->sample); ret = IIO_VAL_INT; break; default: |