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Message-ID: <1544705183-13288-4-git-send-email-stefan.popa@analog.com>
Date: Thu, 13 Dec 2018 14:46:15 +0200
From: Stefan Popa <stefan.popa@...log.com>
To: <jic23@...nel.org>, <robh+dt@...nel.org>, <mark.rutland@....com>
CC: Stefan Popa <stefan.popa@...log.com>,
<Michael.Hennerich@...log.com>, <knaack.h@....de>,
<lars@...afoo.de>, <pmeerw@...erw.net>,
<gregkh@...uxfoundation.org>, <linux-kernel@...r.kernel.org>,
<linux-iio@...r.kernel.org>, <devel@...verdev.osuosl.org>,
<stefan.popa@...log.co>
Subject: [PATCH 03/11] staging: iio: adc: ad7606: Use wait-for-completion handler
This patch replaces the use of wait_event_interruptible() with
wait_for_completion_timeout() when reading the result of a single
conversion. In this way, if the interrupt never occurs, the program will
not remain blocked.
Signed-off-by: Stefan Popa <stefan.popa@...log.com>
---
drivers/staging/iio/adc/ad7606.c | 14 +++++++-------
drivers/staging/iio/adc/ad7606.h | 6 ++----
2 files changed, 9 insertions(+), 11 deletions(-)
diff --git a/drivers/staging/iio/adc/ad7606.c b/drivers/staging/iio/adc/ad7606.c
index aa5ab1e..4b1bc20 100644
--- a/drivers/staging/iio/adc/ad7606.c
+++ b/drivers/staging/iio/adc/ad7606.c
@@ -118,12 +118,13 @@ static int ad7606_scan_direct(struct iio_dev *indio_dev, unsigned int ch)
struct ad7606_state *st = iio_priv(indio_dev);
int ret;
- st->done = false;
gpiod_set_value(st->gpio_convst, 1);
-
- ret = wait_event_interruptible(st->wq_data_avail, st->done);
- if (ret)
+ ret = wait_for_completion_timeout(&st->completion,
+ msecs_to_jiffies(1000));
+ if (!ret) {
+ ret = -ETIMEDOUT;
goto error_ret;
+ }
ret = ad7606_read_samples(st);
if (ret == 0)
@@ -388,8 +389,7 @@ static irqreturn_t ad7606_interrupt(int irq, void *dev_id)
if (iio_buffer_enabled(indio_dev)) {
schedule_work(&st->poll_work);
} else {
- st->done = true;
- wake_up_interruptible(&st->wq_data_avail);
+ complete(&st->completion);
}
return IRQ_HANDLED;
@@ -473,7 +473,7 @@ int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
indio_dev->channels = st->chip_info->channels;
indio_dev->num_channels = st->chip_info->num_channels;
- init_waitqueue_head(&st->wq_data_avail);
+ init_completion(&st->completion);
ret = ad7606_reset(st);
if (ret)
diff --git a/drivers/staging/iio/adc/ad7606.h b/drivers/staging/iio/adc/ad7606.h
index e365fa0..cf20ca2 100644
--- a/drivers/staging/iio/adc/ad7606.h
+++ b/drivers/staging/iio/adc/ad7606.h
@@ -28,11 +28,9 @@ struct ad7606_chip_info {
* @reg regulator info for the the power supply of the device
* @poll_work work struct for continuously reading data from the device
* into an IIO triggered buffer
- * @wq_data_avail wait queue struct for buffer mode
* @bops bus operations (SPI or parallel)
* @range voltage range selection, selects which scale to apply
* @oversampling oversampling selection
- * @done marks whether reading data is done
* @base_address address from where to read data in parallel operation
* @lock protect sensor state from concurrent accesses to GPIOs
* @gpio_convst GPIO descriptor for conversion start signal (CONVST)
@@ -43,6 +41,7 @@ struct ad7606_chip_info {
* @gpio_frstdata GPIO descriptor for reading from device when data
* is being read on the first channel
* @gpio_os GPIO descriptors to control oversampling on the device
+ * @complete completion to indicate end of conversion
* @data buffer for reading data from the device
*/
@@ -51,11 +50,9 @@ struct ad7606_state {
const struct ad7606_chip_info *chip_info;
struct regulator *reg;
struct work_struct poll_work;
- wait_queue_head_t wq_data_avail;
const struct ad7606_bus_ops *bops;
unsigned int range;
unsigned int oversampling;
- bool done;
void __iomem *base_address;
struct mutex lock; /* protect sensor state */
@@ -65,6 +62,7 @@ struct ad7606_state {
struct gpio_desc *gpio_standby;
struct gpio_desc *gpio_frstdata;
struct gpio_descs *gpio_os;
+ struct completion completion;
/*
* DMA (thus cache coherency maintenance) requires the
--
2.7.4
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