| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <cd7c72e3ee00f279d3381873f54e0c5b75b5ad11.1754901948.git.mazziesaccount@gmail.com>
Date: Mon, 11 Aug 2025 11:51:28 +0300
From: Matti Vaittinen <mazziesaccount@...il.com>
To: Matti Vaittinen <mazziesaccount@...il.com>,
Matti Vaittinen <matti.vaittinen@...rohmeurope.com>
Cc: Lars-Peter Clausen <lars@...afoo.de>,
Michael Hennerich <Michael.Hennerich@...log.com>,
Jonathan Cameron <jic23@...nel.org>,
David Lechner <dlechner@...libre.com>,
Nuno Sá <nuno.sa@...log.com>,
Andy Shevchenko <andy@...nel.org>, Rob Herring <robh@...nel.org>,
Krzysztof Kozlowski <krzk+dt@...nel.org>,
Conor Dooley <conor+dt@...nel.org>,
Matti Vaittinen <mazziesaccount@...il.com>,
Liam Girdwood <lgirdwood@...il.com>,
Mark Brown <broonie@...nel.org>, linux-iio@...r.kernel.org,
devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v4 06/11] iio: adc: ad7476: Drop convstart chan_spec
The ad7476 driver defines separate chan_spec structures for operation
with and without convstart GPIO. At quick glance this may seem as if the
driver did provide more than 1 data-channel to users - one for the
regular data, other for the data obtained with the convstart GPIO.
The only difference between the 'convstart' and 'non convstart'
-channels is presence / absence of the BIT(IIO_CHAN_INFO_RAW) in
channel's flags.
We can drop the convstart channel spec, and related convstart macro, by
allocating a mutable per driver instance channel spec and adding the flag
in probe if needed. This will simplify the driver with the cost of added
memory consumption.
Assuming there aren't systems with very many ADCs and very few
resources, this tradeoff seems worth making.
Simplify the driver by dropping the 'convstart' channel spec and
allocating the channel spec for each driver instance.
Signed-off-by: Matti Vaittinen <mazziesaccount@...il.com>
Reviewed-by: Nuno Sá <nuno.sa@...log.com>
Reviewed-by: Andy Shevchenko <andy@...nel.org>
---
Revision history:
v3 => :
- No changes
v2 => v3:
- Use __set_bit() instead of |=
- Swicth BUILD_BUG_ON to static_assert
- Clarify a comment
- Improve commit message
v1 => v2:
- New patch
---
drivers/iio/adc/ad7476.c | 31 +++++++++++++++++++------------
1 file changed, 19 insertions(+), 12 deletions(-)
diff --git a/drivers/iio/adc/ad7476.c b/drivers/iio/adc/ad7476.c
index 1445f0f599d9..ad9e629f0cbd 100644
--- a/drivers/iio/adc/ad7476.c
+++ b/drivers/iio/adc/ad7476.c
@@ -6,6 +6,7 @@
* Copyright 2010 Analog Devices Inc.
*/
+#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/slab.h>
@@ -29,8 +30,6 @@ struct ad7476_state;
struct ad7476_chip_info {
unsigned int int_vref_mv;
struct iio_chan_spec channel[2];
- /* channels used when convst gpio is defined */
- struct iio_chan_spec convst_channel[2];
void (*reset)(struct ad7476_state *);
bool has_vref;
bool has_vdrive;
@@ -42,6 +41,7 @@ struct ad7476_state {
struct gpio_desc *convst_gpio;
struct spi_transfer xfer;
struct spi_message msg;
+ struct iio_chan_spec channel[2];
int scale_mv;
/*
* DMA (thus cache coherency maintenance) may require the
@@ -154,24 +154,18 @@ static int ad7476_read_raw(struct iio_dev *indio_dev,
#define AD7940_CHAN(bits) _AD7476_CHAN((bits), 15 - (bits), \
BIT(IIO_CHAN_INFO_RAW))
#define AD7091R_CHAN(bits) _AD7476_CHAN((bits), 16 - (bits), 0)
-#define AD7091R_CONVST_CHAN(bits) _AD7476_CHAN((bits), 16 - (bits), \
- BIT(IIO_CHAN_INFO_RAW))
#define ADS786X_CHAN(bits) _AD7476_CHAN((bits), 12 - (bits), \
BIT(IIO_CHAN_INFO_RAW))
static const struct ad7476_chip_info ad7091_chip_info = {
.channel[0] = AD7091R_CHAN(12),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
- .convst_channel[0] = AD7091R_CONVST_CHAN(12),
- .convst_channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
.reset = ad7091_reset,
};
static const struct ad7476_chip_info ad7091r_chip_info = {
.channel[0] = AD7091R_CHAN(12),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
- .convst_channel[0] = AD7091R_CONVST_CHAN(12),
- .convst_channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
.int_vref_mv = 2500,
.has_vref = true,
.reset = ad7091_reset,
@@ -282,6 +276,7 @@ static int ad7476_probe(struct spi_device *spi)
{
struct ad7476_state *st;
struct iio_dev *indio_dev;
+ unsigned int i;
int ret;
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
@@ -332,16 +327,28 @@ static int ad7476_probe(struct spi_device *spi)
if (IS_ERR(st->convst_gpio))
return PTR_ERR(st->convst_gpio);
+ /*
+ * This will never happen. Unless someone changes the channel specs
+ * in this driver. And if someone does, without changing the loop
+ * below, then we'd better immediately produce a big fat error, before
+ * the change proceeds from that developer's table.
+ */
+ static_assert(ARRAY_SIZE(st->channel) == ARRAY_SIZE(st->chip_info->channel));
+ for (i = 0; i < ARRAY_SIZE(st->channel); i++) {
+ st->channel[i] = st->chip_info->channel[i];
+ if (st->convst_gpio)
+ __set_bit(IIO_CHAN_INFO_RAW,
+ &st->channel[i].info_mask_separate);
+ }
+
st->spi = spi;
indio_dev->name = spi_get_device_id(spi)->name;
indio_dev->modes = INDIO_DIRECT_MODE;
- indio_dev->channels = st->chip_info->channel;
- indio_dev->num_channels = 2;
+ indio_dev->channels = st->channel;
+ indio_dev->num_channels = ARRAY_SIZE(st->channel);
indio_dev->info = &ad7476_info;
- if (st->convst_gpio)
- indio_dev->channels = st->chip_info->convst_channel;
/* Setup default message */
st->xfer.rx_buf = &st->data;
--
2.50.1
Download attachment "signature.asc" of type "application/pgp-signature" (489 bytes)
Powered by blists - more mailing lists