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From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Jonathan Cameron <jic23@kernel.org>,
	Lars-Peter Clausen <lars@metafoo.de>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
	linux-iio@vger.kernel.org, <linux-kernel@vger.kernel.org>,
	Miquel Raynal <miquel.raynal@bootlin.com>
Subject: [PATCH 03/16] iio: adc: max1027: Push only the requested samples
Date: Wed, 18 Aug 2021 13:11:26 +0200	[thread overview]
Message-ID: <20210818111139.330636-4-miquel.raynal@bootlin.com> (raw)
In-Reply-To: <20210818111139.330636-1-miquel.raynal@bootlin.com>

When a triggered scan occurs, the identity of the desired channels is
known in indio_dev->active_scan_mask. Instead of reading and pushing to
the IIO buffers all channels each time, scan the minimum amount of
channels (0 to maximum requested chan, to be exact) and only provide the
samples requested by the user.

For example, if the user wants channels 1, 4 and 5, all channels from
0 to 5 will be scanned but only the desired channels will be pushed to
the IIO buffers.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/iio/adc/max1027.c | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/adc/max1027.c b/drivers/iio/adc/max1027.c
index b753658bb41e..8ab660f596b5 100644
--- a/drivers/iio/adc/max1027.c
+++ b/drivers/iio/adc/max1027.c
@@ -360,6 +360,9 @@ static int max1027_set_trigger_state(struct iio_trigger *trig, bool state)
 	struct max1027_state *st = iio_priv(indio_dev);
 	int ret;
 
+	if (bitmap_empty(indio_dev->active_scan_mask, indio_dev->masklength))
+		return -EINVAL;
+
 	if (state) {
 		/* Start acquisition on cnvst */
 		st->reg = MAX1027_SETUP_REG | MAX1027_CKS_MODE0 |
@@ -368,9 +371,12 @@ static int max1027_set_trigger_state(struct iio_trigger *trig, bool state)
 		if (ret < 0)
 			return ret;
 
-		/* Scan from 0 to max */
-		st->reg = MAX1027_CONV_REG | MAX1027_CHAN(0) |
-			  MAX1027_SCAN_N_M | MAX1027_TEMP;
+		/*
+		 * Scan from 0 to the highest requested channel. The temperature
+		 * could be avoided but it simplifies a bit the logic.
+		 */
+		st->reg = MAX1027_CONV_REG | MAX1027_SCAN_0_N | MAX1027_TEMP;
+		st->reg |= MAX1027_CHAN(fls(*indio_dev->active_scan_mask) - 2);
 		ret = spi_write(st->spi, &st->reg, 1);
 		if (ret < 0)
 			return ret;
@@ -391,11 +397,22 @@ static irqreturn_t max1027_trigger_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);
+	unsigned int scanned_chans = fls(*indio_dev->active_scan_mask);
+	u16 *buf = st->buffer;
+	unsigned int bit;
 
 	pr_debug("%s(irq=%d, private=0x%p)\n", __func__, irq, private);
 
 	/* fill buffer with all channel */
-	spi_read(st->spi, st->buffer, indio_dev->masklength * 2);
+	spi_read(st->spi, st->buffer, scanned_chans * 2);
+
+	/* Only keep the channels selected by the user */
+	for_each_set_bit(bit, indio_dev->active_scan_mask,
+			 indio_dev->masklength) {
+		if (buf[0] != st->buffer[bit])
+			buf[0] = st->buffer[bit];
+		buf++;
+	}
 
 	iio_push_to_buffers(indio_dev, st->buffer);
 
-- 
2.27.0


  parent reply	other threads:[~2021-08-18 11:12 UTC|newest]

Thread overview: 71+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-18 11:11 [PATCH 00/16] Bring software triggers support to MAX1027-like ADCs Miquel Raynal
2021-08-18 11:11 ` [PATCH 01/16] iio: adc: max1027: Fix wrong shift with 12-bit devices Miquel Raynal
2021-08-20  7:02   ` Sa, Nuno
2021-08-30  9:57     ` Jonathan Cameron
2021-08-18 11:11 ` [PATCH 02/16] iio: adc: max1027: Fix the number of max1X31 channels Miquel Raynal
2021-08-20  7:03   ` Sa, Nuno
2021-08-30 10:00     ` Jonathan Cameron
2021-08-18 11:11 ` Miquel Raynal [this message]
2021-08-20  7:10   ` [PATCH 03/16] iio: adc: max1027: Push only the requested samples Sa, Nuno
2021-08-30 10:07     ` Jonathan Cameron
2021-08-30 10:49       ` Sa, Nuno
2021-08-30 14:29         ` Jonathan Cameron
2021-08-30 15:02           ` Sa, Nuno
2021-09-01  8:12             ` Miquel Raynal
2021-09-04 14:06               ` Jonathan Cameron
2021-09-06  8:59               ` Sa, Nuno
2021-09-06 16:56                 ` Jonathan Cameron
2021-09-06 17:34                   ` Miquel Raynal
2021-08-30 10:06   ` Jonathan Cameron
2021-08-18 11:11 ` [PATCH 04/16] iio: adc: max1027: Lower conversion time Miquel Raynal
2021-08-20  7:12   ` Sa, Nuno
2021-08-30 10:10   ` Jonathan Cameron
2021-08-18 11:11 ` [PATCH 05/16] iio: adc: max1027: Drop extra warning message Miquel Raynal
2021-08-20  7:12   ` Sa, Nuno
2021-08-30 10:12   ` Jonathan Cameron
2021-08-18 11:11 ` [PATCH 06/16] iio: adc: max1027: Rename a helper Miquel Raynal
2021-08-20  7:13   ` Sa, Nuno
2021-08-18 11:11 ` [PATCH 07/16] iio: adc: max1027: Create a helper to configure the trigger Miquel Raynal
2021-08-20  7:16   ` Sa, Nuno
2021-08-30 10:16   ` Jonathan Cameron
2021-08-18 11:11 ` [PATCH 08/16] iio: adc: max1027: Explain better how the trigger state gets changed Miquel Raynal
2021-08-20  7:17   ` Sa, Nuno
2021-08-18 11:11 ` [PATCH 09/16] iio: adc: max1027: Create a helper to configure the channels to scan Miquel Raynal
2021-08-20  7:18   ` Sa, Nuno
2021-08-18 11:11 ` [PATCH 10/16] iio: adc: max1027: Prevent single channel accesses during buffer reads Miquel Raynal
2021-08-20  7:20   ` Sa, Nuno
2021-08-20  7:30     ` Sa, Nuno
2021-08-30 10:20       ` Jonathan Cameron
2021-09-02  8:56         ` Miquel Raynal
2021-08-18 11:11 ` [PATCH 11/16] iio: adc: max1027: Separate the IRQ handler from the read logic Miquel Raynal
2021-08-20  7:23   ` Sa, Nuno
2021-09-02  8:55     ` Miquel Raynal
2021-09-04 14:08       ` Jonathan Cameron
2021-08-18 11:11 ` [PATCH 12/16] iio: adc: max1027: Introduce an end of conversion helper Miquel Raynal
2021-08-20  7:28   ` Sa, Nuno
2021-09-02  9:26     ` Miquel Raynal
2021-08-30 10:34   ` Jonathan Cameron
2021-08-18 11:11 ` [PATCH 13/16] iio: adc: max1027: Prepare re-using the EOC interrupt Miquel Raynal
2021-08-20  7:31   ` Sa, Nuno
2021-08-30 10:30   ` Jonathan Cameron
2021-08-30 10:47   ` Jonathan Cameron
2021-08-18 11:11 ` [PATCH 14/16] iio: adc: max1027: Consolidate the end of conversion helper Miquel Raynal
2021-08-20  7:45   ` Sa, Nuno
2021-08-30 10:37   ` Jonathan Cameron
2021-08-30 12:44     ` Sa, Nuno
2021-08-30 14:32       ` Jonathan Cameron
2021-09-02 15:12       ` Miquel Raynal
2021-09-03 14:28         ` Sa, Nuno
2021-09-03 14:46           ` Miquel Raynal
2021-09-05  9:41             ` Jonathan Cameron
2021-09-06  9:12               ` Sa, Nuno
2021-09-06  9:30                 ` Sa, Nuno
2021-08-18 11:11 ` [PATCH 15/16] iio: adc: max1027: Support software triggers Miquel Raynal
2021-08-20  7:58   ` Sa, Nuno
2021-09-02 12:25     ` Miquel Raynal
2021-09-03 14:20       ` Sa, Nuno
2021-08-30 10:50   ` Jonathan Cameron
2021-09-02 15:21     ` Miquel Raynal
2021-09-05  9:43       ` Jonathan Cameron
2021-08-18 11:11 ` [PATCH 16/16] iio: adc: max1027: Enable software triggers to be used without IRQ Miquel Raynal
2021-08-30 10:54   ` Jonathan Cameron

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