diff options
| author | Jonathan Santos <Jonathan.Santos@analog.com> | 2025-03-06 18:00:43 -0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-04-10 14:39:24 +0200 |
| commit | 967570b52826741f51d5ebdbeff264e425c426ce (patch) | |
| tree | ef47564aa2ea702f8d82cfa05eb4dc963bfde8dd | |
| parent | dd6391006379d7c3ff42936dfa28bb76555b70d4 (diff) | |
iio: adc: ad7768-1: set MOSI idle state to prevent accidental reset
[ Upstream commit 2416cec859299be04d021b4cf98eff814f345af7 ]
Datasheet recommends Setting the MOSI idle state to high in order to
prevent accidental reset of the device when SCLK is free running.
This happens when the controller clocks out a 1 followed by 63 zeros
while the CS is held low.
Check if SPI controller supports SPI_MOSI_IDLE_HIGH flag and set it.
Fixes: a5f8c7da3dbe ("iio: adc: Add AD7768-1 ADC basic support")
Signed-off-by: Jonathan Santos <Jonathan.Santos@analog.com>
Reviewed-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
Link: https://patch.msgid.link/c2a2b0f3d54829079763a5511359a1fa80516cfb.1741268122.git.Jonathan.Santos@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/iio/adc/ad7768-1.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/iio/adc/ad7768-1.c b/drivers/iio/adc/ad7768-1.c index 113703fb7245..6f8816483f1a 100644 --- a/drivers/iio/adc/ad7768-1.c +++ b/drivers/iio/adc/ad7768-1.c @@ -574,6 +574,21 @@ static int ad7768_probe(struct spi_device *spi) return -ENOMEM; st = iio_priv(indio_dev); + /* + * Datasheet recommends SDI line to be kept high when data is not being + * clocked out of the controller and the spi clock is free running, + * to prevent accidental reset. + * Since many controllers do not support the SPI_MOSI_IDLE_HIGH flag + * yet, only request the MOSI idle state to enable if the controller + * supports it. + */ + if (spi->controller->mode_bits & SPI_MOSI_IDLE_HIGH) { + spi->mode |= SPI_MOSI_IDLE_HIGH; + ret = spi_setup(spi); + if (ret < 0) + return ret; + } + st->spi = spi; st->vref = devm_regulator_get(&spi->dev, "vref"); |