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From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Jonathan Cameron <jic23@kernel.org>,
	Lars-Peter Clausen <lars@metafoo.de>,
	linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
	Nuno Sa <Nuno.Sa@analog.com>,
	Miquel Raynal <miquel.raynal@bootlin.com>
Subject: [PATCH v2 14/16] iio: adc: max1027: Don't just sleep when the EOC interrupt is available
Date: Thu,  2 Sep 2021 23:14:35 +0200	[thread overview]
Message-ID: <20210902211437.503623-15-miquel.raynal@bootlin.com> (raw)
In-Reply-To: <20210902211437.503623-1-miquel.raynal@bootlin.com>

The interrupt will fire upon end of conversion. This currently can
happen in two situations: either the cnvst trigger was enabled and
toggled, or a single read was requested and the data is ready. The first
situation is already covered while the second is not. Instead, a waiting
delay is applied. Let's handle these interrupts more properly by adding
second path in our EOC helper.

Rename the interrupt handler to a more generic name as it won't only
handle triggered situations.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/iio/adc/max1027.c | 31 ++++++++++++++++++++++++++++---
 1 file changed, 28 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/adc/max1027.c b/drivers/iio/adc/max1027.c
index b85fe0a48ff9..e734d32a5507 100644
--- a/drivers/iio/adc/max1027.c
+++ b/drivers/iio/adc/max1027.c
@@ -256,15 +256,27 @@ struct max1027_state {
 	struct iio_trigger		*trig;
 	__be16				*buffer;
 	struct mutex			lock;
+	struct completion		complete;
 
 	u8				reg ____cacheline_aligned;
 };
 
 static int max1027_wait_eoc(struct iio_dev *indio_dev)
 {
+	struct max1027_state *st = iio_priv(indio_dev);
 	unsigned int conversion_time = MAX1027_CONVERSION_UDELAY;
+	int ret;
 
-	usleep_range(conversion_time, conversion_time * 2);
+	if (st->spi->irq) {
+		ret = wait_for_completion_timeout(&st->complete,
+						  msecs_to_jiffies(1000));
+		if (!ret)
+			return ret;
+
+		reinit_completion(&st->complete);
+	} else {
+		usleep_range(conversion_time, conversion_time * 2);
+	}
 
 	return 0;
 }
@@ -457,12 +469,24 @@ static int max1027_read_scan(struct iio_dev *indio_dev)
 	return 0;
 }
 
-static irqreturn_t max1027_trigger_handler(int irq, void *private)
+static irqreturn_t max1027_threaded_handler(int irq, void *private)
 {
 	struct iio_poll_func *pf = private;
 	struct iio_dev *indio_dev = pf->indio_dev;
+	struct max1027_state *st = iio_priv(indio_dev);
 	int ret;
 
+	/*
+	 * When buffers are disabled, no trigger is in use but if we are here it
+	 * means that the device IRQ is enabled:
+	 * this is a single read EOC interrupt, we only need to call complete()
+	 * and return.
+	 */
+	if (!iio_buffer_enabled(indio_dev)) {
+		complete(&st->complete);
+		return IRQ_HANDLED;
+	}
+
 	ret = max1027_read_scan(indio_dev);
 	if (ret)
 		dev_err(&indio_dev->dev,
@@ -501,6 +525,7 @@ static int max1027_probe(struct spi_device *spi)
 	st->info = &max1027_chip_info_tbl[spi_get_device_id(spi)->driver_data];
 
 	mutex_init(&st->lock);
+	init_completion(&st->complete);
 
 	indio_dev->name = spi_get_device_id(spi)->name;
 	indio_dev->info = &max1027_info;
@@ -516,7 +541,7 @@ static int max1027_probe(struct spi_device *spi)
 	if (spi->irq) {
 		ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
 						      &iio_pollfunc_store_time,
-						      &max1027_trigger_handler,
+						      &max1027_threaded_handler,
 						      NULL);
 		if (ret < 0) {
 			dev_err(&indio_dev->dev, "Failed to setup buffer\n");
-- 
2.27.0


  parent reply	other threads:[~2021-09-02 21:15 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-02 21:14 [PATCH v2 00/16] Bring external triggers support to MAX1027-like ADCs Miquel Raynal
2021-09-02 21:14 ` [PATCH v2 01/16] iio: adc: max1027: Fix style Miquel Raynal
2021-09-02 21:14 ` [PATCH v2 02/16] iio: adc: max1027: Drop extra warning message Miquel Raynal
2021-09-02 21:14 ` [PATCH v2 03/16] iio: adc: max1027: Drop useless debug messages Miquel Raynal
2021-09-02 21:14 ` [PATCH v2 04/16] iio: adc: max1027: Avoid device managed allocators for DMA purposes Miquel Raynal
2021-09-05 15:26   ` Jonathan Cameron
2021-09-02 21:14 ` [PATCH v2 05/16] iio: adc: max1027: Minimize the number of converted channels Miquel Raynal
2021-09-05 15:34   ` Jonathan Cameron
2021-09-15  9:46     ` Miquel Raynal
2021-09-02 21:14 ` [PATCH v2 06/16] iio: adc: max1027: Rename a helper Miquel Raynal
2021-09-02 21:14 ` [PATCH v2 07/16] iio: adc: max1027: Create a helper to enable/disable the cnvst trigger Miquel Raynal
2021-09-02 21:14 ` [PATCH v2 08/16] iio: adc: max1027: Simplify the _set_trigger_state() helper Miquel Raynal
2021-09-02 21:14 ` [PATCH v2 09/16] iio: adc: max1027: Ensure a default cnvst trigger configuration Miquel Raynal
2021-09-02 21:14 ` [PATCH v2 10/16] iio: adc: max1027: Create a helper to configure the channels to scan Miquel Raynal
2021-09-02 21:14 ` [PATCH v2 11/16] iio: adc: max1027: Prevent single channel accesses during buffer reads Miquel Raynal
2021-09-05 15:38   ` Jonathan Cameron
2021-09-02 21:14 ` [PATCH v2 12/16] iio: adc: max1027: Separate the IRQ handler from the read logic Miquel Raynal
2021-09-02 21:14 ` [PATCH v2 13/16] iio: adc: max1027: Introduce an end of conversion helper Miquel Raynal
2021-09-02 21:14 ` Miquel Raynal [this message]
2021-09-06  9:38   ` [PATCH v2 14/16] iio: adc: max1027: Don't just sleep when the EOC interrupt is available Sa, Nuno
2021-09-15  9:55     ` Miquel Raynal
2021-09-02 21:14 ` [PATCH v2 15/16] iio: adc: max1027: Add support for external triggers Miquel Raynal
2021-09-05 16:10   ` Jonathan Cameron
2021-09-06  9:53     ` Sa, Nuno
2021-09-15 15:45       ` Miquel Raynal
2021-09-18 17:39         ` Jonathan Cameron
2021-09-20 10:47           ` Miquel Raynal
2021-09-15 10:18     ` Miquel Raynal
2021-09-18 17:13       ` Jonathan Cameron
2021-09-20  8:37         ` Miquel Raynal
2021-09-20 17:43           ` Jonathan Cameron
2021-09-21  8:11             ` Miquel Raynal
2021-09-02 21:14 ` [PATCH v2 16/16] iio: adc: max1027: Don't reject external triggers when there is no IRQ Miquel Raynal

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