Tested with a Renesas KingFisher board. Because my GNSS device is hooked up via UART and I2C simultaneously, I could verify functionality by opening/closing the GNSS device using UART and see if the corresponding I2C device was visible on the bus. Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx> --- Changes since RFC v1: * rebased because of patches dropped * bail out correctly when requesting GPIO fails (Thanks, Dan!) drivers/gnss/ubx.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/gnss/ubx.c b/drivers/gnss/ubx.c index 9b76b101ba5e..cb0612100644 100644 --- a/drivers/gnss/ubx.c +++ b/drivers/gnss/ubx.c @@ -7,6 +7,7 @@ #include <linux/errno.h> #include <linux/gnss.h> +#include <linux/gpio/consumer.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/module.h> @@ -18,6 +19,7 @@ struct ubx_data { struct regulator *vcc; + struct gpio_desc *reset_gpio; }; static int ubx_set_active(struct gnss_serial *gserial) @@ -29,6 +31,8 @@ static int ubx_set_active(struct gnss_serial *gserial) if (ret) return ret; + gpiod_set_value_cansleep(data->reset_gpio, 0); + return 0; } @@ -41,6 +45,8 @@ static int ubx_set_standby(struct gnss_serial *gserial) if (ret) return ret; + gpiod_set_value_cansleep(data->reset_gpio, 1); + return 0; } @@ -90,6 +96,13 @@ static int ubx_probe(struct serdev_device *serdev) if (ret < 0 && ret != -ENODEV) goto err_free_gserial; + /* Start with reset asserted (GPIO must be active low!) */ + data->reset_gpio = devm_gpiod_get_optional(&serdev->dev, "reset", GPIOD_OUT_HIGH); + if (IS_ERR(data->reset_gpio)) { + ret = PTR_ERR(data->reset_gpio); + goto err_free_gserial; + } + ret = gnss_serial_register(gserial); if (ret) goto err_free_gserial; -- 2.30.2