diff options
| author | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2014-03-03 19:07:00 +0100 |
|---|---|---|
| committer | Jonathan Cameron <jic23@kernel.org> | 2014-03-15 17:32:44 +0100 |
| commit | 8f32b6ba56ef8c8434635b9f08ff6a23510960a5 (patch) | |
| tree | 78c32af0f5b53021173824512be68f77fd6ebb9d /drivers/iio/adc/at91_adc.c | |
| parent | ARM: at91: at91sam9260: change at91_adc name (diff) | |
| download | linux-8f32b6ba56ef8c8434635b9f08ff6a23510960a5.tar.xz linux-8f32b6ba56ef8c8434635b9f08ff6a23510960a5.zip | |
iio: adc: at91_adc: correct default shtim value
When sample_hold_time is zero (this is the case when DT is not used or if
atmel,adc-sample-hold-time is omitted), then the calculated shtim is large.
Make that 0, which is the default for that register and the ADC will then use a
sane value of 2/ADCCLK or 1/ADCCLK depending on the version.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Josh Wu <josh.wu@atmel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Diffstat (limited to 'drivers/iio/adc/at91_adc.c')
| -rw-r--r-- | drivers/iio/adc/at91_adc.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c index bbba014c9939..89777ed9abd8 100644 --- a/drivers/iio/adc/at91_adc.c +++ b/drivers/iio/adc/at91_adc.c @@ -1007,8 +1007,11 @@ static int at91_adc_probe(struct platform_device *pdev) * the best converted final value between two channels selection * The formula thus is : Sample and Hold Time = (shtim + 1) / ADCClock */ - shtim = round_up((st->sample_hold_time * adc_clk_khz / - 1000) - 1, 1); + if (st->sample_hold_time > 0) + shtim = round_up((st->sample_hold_time * adc_clk_khz / 1000) + - 1, 1); + else + shtim = 0; reg = AT91_ADC_PRESCAL_(prsc) & st->registers->mr_prescal_mask; reg |= AT91_ADC_STARTUP_(ticks) & st->registers->mr_startup_mask; |