releases/4.16.14/iio-adc-stm32-dfsdm-fix-sample-rate-for-div2-spi-clock.patch

   1 From d58109dcf37fc9baec354385ec9fdcd8878d174d Mon Sep 17 00:00:00 2001
   2 From: Fabrice Gasnier <fabrice.gasnier@st.com>
   3 Date: Tue, 13 Mar 2018 15:23:06 +0100
   4 Subject: iio: adc: stm32-dfsdm: fix sample rate for div2 spi clock
   5
   6 From: Fabrice Gasnier <fabrice.gasnier@st.com>
   7
   8 commit d58109dcf37fc9baec354385ec9fdcd8878d174d upstream.
   9
  10 When channel clk source is set to "CLKOUT_F" or "CLKOUT_R" (e.g. div2),
  11 sample rate is currently set to half the requested value.
  12
  13 Fixes: eca949800d2d ("IIO: ADC: add stm32 DFSDM support for PDM
  14 microphone")
  15
  16 Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
  17 Acked-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
  18 Cc: <Stable@vger.kernel.org>
  19 Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
  20 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  21
  22 ---
  23  drivers/iio/adc/stm32-dfsdm-adc.c |   14 ++++++++++++--
  24  1 file changed, 12 insertions(+), 2 deletions(-)
  25
  26 --- a/drivers/iio/adc/stm32-dfsdm-adc.c
  27 +++ b/drivers/iio/adc/stm32-dfsdm-adc.c
  28 @@ -771,7 +771,7 @@ static int stm32_dfsdm_write_raw(struct
  29         struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
  30         struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id];
  31         struct stm32_dfsdm_channel *ch = &adc->dfsdm->ch_list[chan->channel];
  32 -       unsigned int spi_freq = adc->spi_freq;
  33 +       unsigned int spi_freq;
  34         int ret = -EINVAL;
  35
  36         switch (mask) {
  37 @@ -785,8 +785,18 @@ static int stm32_dfsdm_write_raw(struct
  38         case IIO_CHAN_INFO_SAMP_FREQ:
  39                 if (!val)
  40                         return -EINVAL;
  41 -               if (ch->src != DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL)
  42 +
  43 +               switch (ch->src) {
  44 +               case DFSDM_CHANNEL_SPI_CLOCK_INTERNAL:
  45                         spi_freq = adc->dfsdm->spi_master_freq;
  46 +                       break;
  47 +               case DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_FALLING:
  48 +               case DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_RISING:
  49 +                       spi_freq = adc->dfsdm->spi_master_freq / 2;
  50 +                       break;
  51 +               default:
  52 +                       spi_freq = adc->spi_freq;
  53 +               }
  54
  55                 if (spi_freq % val)
  56                         dev_warn(&indio_dev->dev,