From dee81110a4888cf8eb419434c0ad687129c7d0fd Mon Sep 17 00:00:00 2001 From: Dragos Bogdan Date: Wed, 29 Apr 2020 10:21:29 +0300 Subject: [PATCH] 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 Signed-off-by: Alexandru Ardelean Cc: Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/staging/iio/resolver/ad2s1210.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/drivers/staging/iio/resolver/ad2s1210.c b/drivers/staging/iio/resolver/ad2s1210.c index 4b25a3a..ed40435 100644 --- a/drivers/staging/iio/resolver/ad2s1210.c +++ b/drivers/staging/iio/resolver/ad2s1210.c @@ -130,17 +130,24 @@ 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; -- 2.7.4