diff options
| author | Nikita Yushchenko <nikita.yoush@cogentembedded.com> | 2017-05-19 17:48:02 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-04-13 19:50:08 +0200 |
| commit | a091f8aba517114ddf4922492b6e110d580cadbd (patch) | |
| tree | abf7124aae66a6f482f5f02830301ec702f86c6d /drivers/iio | |
| parent | ce839ed8186ca60a95373df042f806a64284f2e7 (diff) | |
iio: hi8435: cleanup reset gpio
[ Upstream commit 61305664a542f874283f74bf0b27ddb31f5045d7 ]
Reset GPIO is active low.
Currently driver uses gpiod_set_value(1) to clean reset, which depends
on device tree to contain GPIO_ACTIVE_HIGH - that does not match reality.
This fixes driver to use _raw version of gpiod_set_value() to enforce
active-low semantics despite of what's written in device tree. Allowing
device tree to override that only opens possibility for errors and does
not add any value.
Additionally, use _cansleep version to make things work with i2c-gpio
and other sleeping gpio drivers.
Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/iio')
| -rw-r--r-- | drivers/iio/adc/hi8435.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/drivers/iio/adc/hi8435.c b/drivers/iio/adc/hi8435.c index ba9e8fc747b8..7401f102dff4 100644 --- a/drivers/iio/adc/hi8435.c +++ b/drivers/iio/adc/hi8435.c @@ -453,13 +453,15 @@ static int hi8435_probe(struct spi_device *spi) priv->spi = spi; reset_gpio = devm_gpiod_get(&spi->dev, NULL, GPIOD_OUT_LOW); - if (IS_ERR(reset_gpio)) { - /* chip s/w reset if h/w reset failed */ + if (!IS_ERR(reset_gpio)) { + /* need >=100ns low pulse to reset chip */ + gpiod_set_raw_value_cansleep(reset_gpio, 0); + udelay(1); + gpiod_set_raw_value_cansleep(reset_gpio, 1); + } else { + /* s/w reset chip if h/w reset is not available */ hi8435_writeb(priv, HI8435_CTRL_REG, HI8435_CTRL_SRST); hi8435_writeb(priv, HI8435_CTRL_REG, 0); - } else { - udelay(5); - gpiod_set_value(reset_gpio, 1); } spi_set_drvdata(spi, idev); |