From: Ladislav Michl ladis@linux-mips.org
[ Upstream commit fe895ac88b9fbdf2026f0bfd56c82747bb9d7c48 ]
As user's guide "ADS1015EVM, ADS1115EVM, ADS1015EVM-PDK, ADS1115EVM-PDK User Guide (Rev. B)" (http://www.ti.com/lit/ug/sbau157b/sbau157b.pdf) states at page 16: "Note that both the ADS1115 and ADS1015 have internal clocks with a ±10% accuracy. If performing FFT tests, frequencies may appear to be incorrect as a result of this tolerance range.", add those 10% to converion wait time.
Cc: Daniel Baluta daniel.baluta@gmail.com Cc: Jonathan Cameron jic23@kernel.org Signed-off-by: Ladislav Michl ladis@linux-mips.org Reviewed-by: Akinobu Mita akinobu.mita@gmail.com Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Sasha Levin alexander.levin@verizon.com --- drivers/iio/adc/ti-ads1015.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/iio/adc/ti-ads1015.c b/drivers/iio/adc/ti-ads1015.c index e0dc20488335..9ac2fb032df6 100644 --- a/drivers/iio/adc/ti-ads1015.c +++ b/drivers/iio/adc/ti-ads1015.c @@ -369,6 +369,7 @@ int ads1015_get_adc_result(struct ads1015_data *data, int chan, int *val)
conv_time = DIV_ROUND_UP(USEC_PER_SEC, data->data_rate[dr_old]); conv_time += DIV_ROUND_UP(USEC_PER_SEC, data->data_rate[dr]); + conv_time += conv_time / 10; /* 10% internal clock inaccuracy */ usleep_range(conv_time, conv_time + 1); data->conv_invalid = false; }