From 750ac07eb2c85617b5522402a99b4b408cd0b1b3 Mon Sep 17 00:00:00 2001 From: Freeman Liu Date: Fri, 9 Nov 2018 11:25:31 +0800 Subject: [PATCH] iio: adc: sc27xx: Add ADC data conversion timeout Sometimes the ADC controller met some problems, and it will not complete the data conversion, that will can not wake up the read process any more to block users. So we should add one maximum conversion time to avoid this issue. Signed-off-by: Freeman Liu Signed-off-by: Baolin Wang Signed-off-by: Jonathan Cameron --- drivers/iio/adc/sc27xx_adc.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/iio/adc/sc27xx_adc.c b/drivers/iio/adc/sc27xx_adc.c index 7940b23..f7f7a189 100644 --- a/drivers/iio/adc/sc27xx_adc.c +++ b/drivers/iio/adc/sc27xx_adc.c @@ -52,6 +52,9 @@ /* Timeout (ms) for the trylock of hardware spinlocks */ #define SC27XX_ADC_HWLOCK_TIMEOUT 5000 +/* Timeout (ms) for ADC data conversion according to ADC datasheet */ +#define SC27XX_ADC_RDY_TIMEOUT 100 + /* Maximum ADC channel number */ #define SC27XX_ADC_CHANNEL_MAX 32 @@ -223,7 +226,14 @@ static int sc27xx_adc_read(struct sc27xx_adc_data *data, int channel, if (ret) goto disable_adc; - wait_for_completion(&data->completion); + ret = wait_for_completion_timeout(&data->completion, + msecs_to_jiffies(SC27XX_ADC_RDY_TIMEOUT)); + if (!ret) { + dev_err(data->dev, "read ADC data timeout\n"); + ret = -ETIMEDOUT; + } else { + ret = 0; + } disable_adc: regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL, -- 2.7.4