From 750ac07eb2c85617b5522402a99b4b408cd0b1b3 Mon Sep 17 00:00:00 2001
From: Freeman Liu <freeman.liu@unisoc.com>
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 <freeman.liu@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
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 7940b23dcad90..f7f7a18904b45 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,
--
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