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 v3 12/14] iio: adc: max1027: Introduce an end of conversion helper
Date: Wed, 15 Sep 2021 17:51:15 +0200 [thread overview]
Message-ID: <20210915155117.475962-13-miquel.raynal@bootlin.com> (raw)
In-Reply-To: <20210915155117.475962-1-miquel.raynal@bootlin.com>
For now this helper only waits for the maximum duration of a single
conversion (even though a temperature measurement will take twice this
time, we only care about the temperature which happens first, so we will
still only wait for a single sample).
This helper will soon be improved to properly handle the end of
conversion interrupt as well as a higher number of samples.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
drivers/iio/adc/max1027.c | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/drivers/iio/adc/max1027.c b/drivers/iio/adc/max1027.c
index a044f4b598e0..e0175448c899 100644
--- a/drivers/iio/adc/max1027.c
+++ b/drivers/iio/adc/max1027.c
@@ -60,6 +60,9 @@
#define MAX1027_NAVG_32 (0x03 << 2)
#define MAX1027_AVG_EN BIT(4)
+/* Device can achieve 300ksps so we assume a 3.33us conversion delay */
+#define MAX1027_CONVERSION_UDELAY 4
+
enum max1027_id {
max1027,
max1029,
@@ -271,6 +274,15 @@ struct max1027_state {
u8 reg ____cacheline_aligned;
};
+static int max1027_wait_eoc(struct iio_dev *indio_dev)
+{
+ unsigned int conversion_time = MAX1027_CONVERSION_UDELAY;
+
+ usleep_range(conversion_time, conversion_time * 2);
+
+ return 0;
+}
+
/* Scan from chan 0 to the highest requested channel. Include temperature on demand. */
static int max1027_configure_chans_and_start(struct iio_dev *indio_dev)
{
@@ -330,9 +342,11 @@ static int max1027_read_single_value(struct iio_dev *indio_dev,
/*
* For an unknown reason, when we use the mode "10" (write
* conversion register), the interrupt doesn't occur every time.
- * So we just wait 1 ms.
+ * So we just wait the maximum conversion time and deliver the value.
*/
- mdelay(1);
+ ret = max1027_wait_eoc(indio_dev);
+ if (ret)
+ return ret;
/* Read result */
ret = spi_read(st->spi, st->buffer, (chan->type == IIO_TEMP) ? 4 : 2);
--
2.27.0
next prev parent reply other threads:[~2021-09-15 15:52 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-15 15:51 [PATCH v3 00/14] Bring external triggers support to MAX1027-like ADCs Miquel Raynal
2021-09-15 15:51 ` [PATCH v3 01/14] iio: adc: max1027: Fix style Miquel Raynal
2021-09-15 15:51 ` [PATCH v3 02/14] iio: adc: max1027: Drop extra warning message Miquel Raynal
2021-09-15 15:51 ` [PATCH v3 03/14] iio: adc: max1027: Drop useless debug messages Miquel Raynal
2021-09-15 15:51 ` [PATCH v3 04/14] iio: adc: max1027: Minimize the number of converted channels Miquel Raynal
2021-09-15 15:51 ` [PATCH v3 05/14] iio: adc: max1027: Rename a helper Miquel Raynal
2021-09-15 15:51 ` [PATCH v3 06/14] iio: adc: max1027: Create a helper to enable/disable the cnvst trigger Miquel Raynal
2021-09-15 15:51 ` [PATCH v3 07/14] iio: adc: max1027: Simplify the _set_trigger_state() helper Miquel Raynal
2021-09-15 15:51 ` [PATCH v3 08/14] iio: adc: max1027: Ensure a default cnvst trigger configuration Miquel Raynal
2021-09-15 15:51 ` [PATCH v3 09/14] iio: adc: max1027: Create a helper to configure the channels to scan Miquel Raynal
2021-09-15 15:51 ` [PATCH v3 10/14] iio: adc: max1027: Prevent single channel accesses during buffer reads Miquel Raynal
2021-09-15 15:51 ` [PATCH v3 11/14] iio: adc: max1027: Separate the IRQ handler from the read logic Miquel Raynal
2021-09-15 15:51 ` Miquel Raynal [this message]
2021-09-15 15:51 ` [PATCH v3 13/14] iio: adc: max1027: Deeply rework interrupt handling Miquel Raynal
2021-09-18 17:09 ` Jonathan Cameron
2021-09-15 15:51 ` [PATCH v3 14/14] iio: adc: max1027: Don't reject external triggers when there is no IRQ Miquel Raynal
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