summaryrefslogtreecommitdiffstats
path: root/drivers/iio/adc/hi8435.c
diff options
context:
space:
mode:
authorNikita Yushchenko <nikita.yoush@cogentembedded.com>2017-05-19 17:48:02 +0300
committerJonathan Cameron <jic23@kernel.org>2017-05-20 17:35:52 +0100
commit61305664a542f874283f74bf0b27ddb31f5045d7 (patch)
tree2fa42a17780b8a4370ff5f484546e5ce083ae261 /drivers/iio/adc/hi8435.c
parentbd7026992f203d7a0b7e26d53b0b05739454f1df (diff)
downloadlinux-61305664a542f874283f74bf0b27ddb31f5045d7.tar.bz2
iio: hi8435: cleanup reset gpio
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>
Diffstat (limited to 'drivers/iio/adc/hi8435.c')
-rw-r--r--drivers/iio/adc/hi8435.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/drivers/iio/adc/hi8435.c b/drivers/iio/adc/hi8435.c
index d09cb6ff8044..ab59969b7c49 100644
--- a/drivers/iio/adc/hi8435.c
+++ b/drivers/iio/adc/hi8435.c
@@ -476,13 +476,15 @@ 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);