diff options
| author | Ludovic Desroches <ludovic.desroches@atmel.com> | 2016-03-22 17:08:45 +0100 |
|---|---|---|
| committer | Jonathan Cameron <jic23@kernel.org> | 2016-04-03 11:13:58 +0100 |
| commit | 94b24230196da3cd6bd58235137f9a7438983c73 (patch) | |
| tree | 1b6926aa70d2d1e7a258afe975599c034b9161d0 /drivers/iio/adc/at91-sama5d2_adc.c | |
| parent | 22d199a53910e2b1666bf873f10779a66844c126 (diff) | |
iio:adc:at91-sama5d2: cleanup mode register use
Do not erase previous configuration of the mode register when setting
the sampling frequency.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Diffstat (limited to 'drivers/iio/adc/at91-sama5d2_adc.c')
| -rw-r--r-- | drivers/iio/adc/at91-sama5d2_adc.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c index 5bc038f23609..01ba1068613e 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); |