From 4cfcb2bfdd07b130f05a3fb39edd6bfa2a59bf7a Mon Sep 17 00:00:00 2001 From: Fabrice Gasnier Date: Fri, 23 Feb 2018 13:51:01 +0100 Subject: [PATCH] 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 Signed-off-by: Jonathan Cameron --- drivers/iio/adc/stm32-dfsdm-core.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/iio/adc/stm32-dfsdm-core.c b/drivers/iio/adc/stm32-dfsdm-core.c index 6290332cfd3f..540d42cf6f4c 100644 --- a/drivers/iio/adc/stm32-dfsdm-core.c +++ b/drivers/iio/adc/stm32-dfsdm-core.c @@ -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) { -- 2.30.2