From: Fabrice Gasnier Date: Fri, 23 Feb 2018 12:51:01 +0000 (+0100) Subject: iio: adc: stm32-dfsdm: add check on spi-max-frequency X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=4cfcb2bfdd07b130f05a3fb39edd6bfa2a59bf7a;p=linux.git 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 --- diff --git a/drivers/iio/adc/stm32-dfsdm-core.c b/drivers/iio/adc/stm32-dfsdm-core.c index 6290332cfd3f8..540d42cf6f4ce 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) {