diff options
| author | Dragos Bogdan <dragos.bogdan@analog.com> | 2020-04-29 10:21:29 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-05-27 16:43:10 +0200 |
| commit | 03e79b6c34e698da9c17da95f2db76e6a2f2578c (patch) | |
| tree | 55fd1f762d7ec5e7eef83d8420773f1c70e67255 | |
| parent | 33448dc95224b861f2478d42f5bf83c1a695f09e (diff) | |
staging: iio: ad2s1210: Fix SPI reading
commit 5e4f99a6b788047b0b8a7496c2e0c8f372f6edf2 upstream.
If the serial interface is used, the 8-bit address should be latched using
the rising edge of the WR/FSYNC signal.
This basically means that a CS change is required between the first byte
sent, and the second one.
This change splits the single-transfer transfer of 2 bytes into 2 transfers
with a single byte, and CS change in-between.
Note fixes tag is not accurate, but reflects a point beyond which there
are too many refactors to make backporting straight forward.
Fixes: b19e9ad5e2cb ("staging:iio:resolver:ad2s1210 general driver cleanup.")
Signed-off-by: Dragos Bogdan <dragos.bogdan@analog.com>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/staging/iio/resolver/ad2s1210.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/drivers/staging/iio/resolver/ad2s1210.c b/drivers/staging/iio/resolver/ad2s1210.c index 3e00df74b18c..989d5eca8861 100644 --- a/drivers/staging/iio/resolver/ad2s1210.c +++ b/drivers/staging/iio/resolver/ad2s1210.c @@ -126,17 +126,24 @@ static int ad2s1210_config_write(struct ad2s1210_state *st, u8 data) static int ad2s1210_config_read(struct ad2s1210_state *st, unsigned char address) { - struct spi_transfer xfer = { - .len = 2, - .rx_buf = st->rx, - .tx_buf = st->tx, + struct spi_transfer xfers[] = { + { + .len = 1, + .rx_buf = &st->rx[0], + .tx_buf = &st->tx[0], + .cs_change = 1, + }, { + .len = 1, + .rx_buf = &st->rx[1], + .tx_buf = &st->tx[1], + }, }; int ret = 0; ad2s1210_set_mode(MOD_CONFIG, st); st->tx[0] = address | AD2S1210_MSB_IS_HIGH; st->tx[1] = AD2S1210_REG_FAULT; - ret = spi_sync_transfer(st->sdev, &xfer, 1); + ret = spi_sync_transfer(st->sdev, xfers, 2); if (ret < 0) return ret; st->old_data = true; |