On 22/03/16 16:08, Ludovic Desroches wrote: > Do not erase previous configuration of the mode register when setting > the sampling frequency. > > Signed-off-by: Ludovic Desroches <[email protected]> Applied. > --- > drivers/iio/adc/at91-sama5d2_adc.c | 15 ++++++++++----- > 1 file changed, 10 insertions(+), 5 deletions(-) > > diff --git a/drivers/iio/adc/at91-sama5d2_adc.c > b/drivers/iio/adc/at91-sama5d2_adc.c > index 5bc038f..01ba106 100644 > --- a/drivers/iio/adc/at91-sama5d2_adc.c > +++ b/drivers/iio/adc/at91-sama5d2_adc.c > @@ -66,8 +66,10 @@ > #define AT91_SAMA5D2_MR_PRESCAL(v) ((v) << > AT91_SAMA5D2_MR_PRESCAL_OFFSET) > #define AT91_SAMA5D2_MR_PRESCAL_OFFSET 8 > #define AT91_SAMA5D2_MR_PRESCAL_MAX 0xff > +#define AT91_SAMA5D2_MR_PRESCAL_MASK GENMASK(15, 8) > /* Startup Time */ > #define AT91_SAMA5D2_MR_STARTUP(v) ((v) << 16) > +#define AT91_SAMA5D2_MR_STARTUP_MASK GENMASK(19, 16) > /* Analog Change */ > #define AT91_SAMA5D2_MR_ANACH BIT(23) > /* Tracking Time */ > @@ -226,7 +228,7 @@ static unsigned at91_adc_startup_time(unsigned > startup_time_min, > static void at91_adc_setup_samp_freq(struct at91_adc_state *st, unsigned > freq) > { > struct iio_dev *indio_dev = iio_priv_to_dev(st); > - unsigned f_per, prescal, startup; > + unsigned f_per, prescal, startup, mr; > > f_per = clk_get_rate(st->per_clk); > prescal = (f_per / (2 * freq)) - 1; > @@ -234,10 +236,11 @@ static void at91_adc_setup_samp_freq(struct > at91_adc_state *st, unsigned freq) > startup = at91_adc_startup_time(st->soc_info.startup_time, > freq / 1000); > > - at91_adc_writel(st, AT91_SAMA5D2_MR, > - AT91_SAMA5D2_MR_TRANSFER(2) > - | AT91_SAMA5D2_MR_STARTUP(startup) > - | AT91_SAMA5D2_MR_PRESCAL(prescal)); > + mr = at91_adc_readl(st, AT91_SAMA5D2_MR); > + mr &= ~(AT91_SAMA5D2_MR_STARTUP_MASK | AT91_SAMA5D2_MR_PRESCAL_MASK); > + mr |= AT91_SAMA5D2_MR_STARTUP(startup); > + mr |= AT91_SAMA5D2_MR_PRESCAL(prescal); > + at91_adc_writel(st, AT91_SAMA5D2_MR, mr); > > dev_dbg(&indio_dev->dev, "freq: %u, startup: %u, prescal: %u\n", > freq, startup, prescal); > @@ -444,6 +447,8 @@ static int at91_adc_probe(struct platform_device *pdev) > > at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_SWRST); > at91_adc_writel(st, AT91_SAMA5D2_IDR, 0xffffffff); > + /* Transfer field must be set to 2 according to the datasheet. */ > + at91_adc_writel(st, AT91_SAMA5D2_MR, AT91_SAMA5D2_MR_TRANSFER(2)); > > at91_adc_setup_samp_freq(st, st->soc_info.min_sample_rate); > >
