This is a note to let you know that I've just added the patch titled
iio: adc: ad9467: fix reset gpio handling
to the 6.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iio-adc-ad9467-fix-reset-gpio-handling.patch
and it can be found in the queue-6.7 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 0eb72eb81ed5c89d306d0050b4a3004be08acb85
Author: Nuno Sa <nuno.sa@xxxxxxxxxx>
Date: Thu Dec 7 13:39:24 2023 +0100
iio: adc: ad9467: fix reset gpio handling
[ Upstream commit 76f028539cf360f750efd8cde560edda298e4c6b ]
The reset gpio was being handled with inverted polarity. This means that
as far as gpiolib is concerned we were actually leaving the pin asserted
(in theory, this would mean reset). However, inverting the polarity in
devicetree made things work. Fix it by doing it the proper way and how
gpiolib expects it to be done.
While at it, moved the handling to it's own function and dropped
'reset_gpio' from the 'struct ad9467_state' as we only need it during
probe. On top of that, refactored things so that we now request the gpio
asserted (i.e in reset) and then de-assert it. Also note that we now use
gpiod_set_value_cansleep() instead of gpiod_direction_output() as we
already request the pin as output.
Fixes: ad6797120238 ("iio: adc: ad9467: add support AD9467 ADC")
Reviewed-by: David Lechner <dlechner@xxxxxxxxxxxx>
Signed-off-by: Nuno Sa <nuno.sa@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20231207-iio-backend-prep-v2-1-a4a33bc4d70e@xxxxxxxxxx
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/iio/adc/ad9467.c b/drivers/iio/adc/ad9467.c
index 39eccc28debe..4fb9e48dc782 100644
--- a/drivers/iio/adc/ad9467.c
+++ b/drivers/iio/adc/ad9467.c
@@ -121,7 +121,6 @@ struct ad9467_state {
unsigned int output_mode;
struct gpio_desc *pwrdown_gpio;
- struct gpio_desc *reset_gpio;
};
static int ad9467_spi_read(struct spi_device *spi, unsigned int reg)
@@ -378,6 +377,21 @@ static int ad9467_preenable_setup(struct adi_axi_adc_conv *conv)
return ad9467_outputmode_set(st->spi, st->output_mode);
}
+static int ad9467_reset(struct device *dev)
+{
+ struct gpio_desc *gpio;
+
+ gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
+ if (IS_ERR_OR_NULL(gpio))
+ return PTR_ERR_OR_ZERO(gpio);
+
+ fsleep(1);
+ gpiod_set_value_cansleep(gpio, 0);
+ fsleep(10 * USEC_PER_MSEC);
+
+ return 0;
+}
+
static int ad9467_probe(struct spi_device *spi)
{
const struct ad9467_chip_info *info;
@@ -408,18 +422,9 @@ static int ad9467_probe(struct spi_device *spi)
if (IS_ERR(st->pwrdown_gpio))
return PTR_ERR(st->pwrdown_gpio);
- st->reset_gpio = devm_gpiod_get_optional(&spi->dev, "reset",
- GPIOD_OUT_LOW);
- if (IS_ERR(st->reset_gpio))
- return PTR_ERR(st->reset_gpio);
-
- if (st->reset_gpio) {
- udelay(1);
- ret = gpiod_direction_output(st->reset_gpio, 1);
- if (ret)
- return ret;
- mdelay(10);
- }
+ ret = ad9467_reset(&spi->dev);
+ if (ret)
+ return ret;
conv->chip_info = &info->axi_adc_info;
