6.12-stable review patch. If anyone has any objections, please let me know.
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From: Jonathan Santos Jonathan.Santos@analog.com
[ 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... Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/iio/adc/ad7768-1.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)
diff --git a/drivers/iio/adc/ad7768-1.c b/drivers/iio/adc/ad7768-1.c index 113703fb72454..6f8816483f1a0 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");