Hi Wolfram,
On Wed, Jul 12, 2023 at 1:40 PM Wolfram Sang
<wsa+renesas@xxxxxxxxxxxxxxxxxxxx> wrote:
> 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>
Thanks for your patch!
> --- a/drivers/gnss/ubx.c
> +++ b/drivers/gnss/ubx.c
> @@ -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);
Please assert reset before disabling the regulator, for symmetry
with ubx_set_active().
> +
> 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!) */
Does it have to be active low?
The description in your DT bindings suggest both active low and active
high are possible.
I think you just wanted to express that GPIOD_OUT_HIGH means asserted,
i.e. low for the common case of an active-low reset?
> + 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;
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
