diff options
author | Nuno Sá <nuno.sa@analog.com> | 2020-02-10 15:26:03 +0200 |
---|---|---|
committer | Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2020-03-08 17:28:30 +0000 |
commit | ecb010d441088c447785a1249e69003437f96c9c (patch) | |
tree | 07e6220f1d868601cb3ac5dad4db8e6de8ee22b5 /drivers/iio | |
parent | fdcf6bbb4ed388844e74810e117ac87db1347f3a (diff) | |
download | linux-ecb010d441088c447785a1249e69003437f96c9c.tar.bz2 |
iio: imu: adis: Refactor adis_initial_startup
All the ADIS devices perform, at the beginning, a self test to make sure
the device is in a sane state. Previously, the logic was that the self-test
was performed in adis_initial_startup() and if that failed a reset was done
and then a self-test was attempted again.
This change unifies the reset mechanism under the adis_initial_startup()
call. A HW reset will be done if GPIO is configured, or a SW reset
otherwise. This should make sure that the chip is in a sane state for
self-test. Once the reset is done, the self-test operation will be
performed. If anything goes wrong with self-test, the driver should just
bail/error-out (i.e. no second attempt). The chip would likely not be a in
a sane state state if the self-test fails after a reset.
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'drivers/iio')
-rw-r--r-- | drivers/iio/imu/adis.c | 29 |
1 files changed, 22 insertions, 7 deletions
diff --git a/drivers/iio/imu/adis.c b/drivers/iio/imu/adis.c index f7845a90f376..0bd6e32cf577 100644 --- a/drivers/iio/imu/adis.c +++ b/drivers/iio/imu/adis.c @@ -7,6 +7,7 @@ */ #include <linux/delay.h> +#include <linux/gpio/consumer.h> #include <linux/mutex.h> #include <linux/device.h> #include <linux/kernel.h> @@ -368,6 +369,10 @@ static int adis_self_test(struct adis *adis) * __adis_initial_startup() - Device initial setup * @adis: The adis device * + * The function performs a HW reset via a reset pin that should be specified + * via GPIOLIB. If no pin is configured a SW reset will be performed. + * The RST pin for the ADIS devices should be configured as ACTIVE_LOW. + * * Returns 0 if the device is operational, a negative error code otherwise. * * This function should be called early on in the device initialization sequence @@ -375,18 +380,28 @@ static int adis_self_test(struct adis *adis) */ int __adis_initial_startup(struct adis *adis) { + const struct adis_timeout *timeouts = adis->data->timeouts; + struct gpio_desc *gpio; int ret; - ret = adis_self_test(adis); - if (ret) { - dev_err(&adis->spi->dev, "Self-test failed, trying reset.\n"); - __adis_reset(adis); - ret = adis_self_test(adis); + /* check if the device has rst pin low */ + gpio = devm_gpiod_get_optional(&adis->spi->dev, "reset", GPIOD_ASIS); + if (IS_ERR(gpio)) + return PTR_ERR(gpio); + + if (gpio) { + gpiod_set_value_cansleep(gpio, 1); + msleep(10); + /* bring device out of reset */ + gpiod_set_value_cansleep(gpio, 0); + msleep(timeouts->reset_ms); + } else { + ret = __adis_reset(adis); if (ret) - dev_err(&adis->spi->dev, "Second self-test failed, giving up.\n"); + return ret; } - return ret; + return adis_self_test(adis); } EXPORT_SYMBOL_GPL(__adis_initial_startup); |