iio: adc: stm32-dfsdm: add check on spi-max-frequency

spi-max-frequency is requested for SPI master mode (only), to tune output
clock. It may happen requested frequency isn't reachable.
Add explicit check, so probe fails with error in this case. Otherwise,
output clock may simply be silently turned off (conversions fail).

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Fabrice Gasnier 2018-02-23 13:51:01 +01:00 committed by Jonathan Cameron
parent dfa105b1f6
commit 4cfcb2bfdd

View File

@ -219,6 +219,11 @@ static int stm32_dfsdm_parse_of(struct platform_device *pdev,
}
priv->spi_clk_out_div = div_u64_rem(clk_freq, spi_freq, &rem) - 1;
if (!priv->spi_clk_out_div) {
/* spi_clk_out_div == 0 means ckout is OFF */
dev_err(&pdev->dev, "spi-max-frequency not achievable\n");
return -EINVAL;
}
priv->dfsdm.spi_master_freq = spi_freq;
if (rem) {