On Fri, Aug 20, 2021 at 9:53 AM Nuno Sá <nuno.sa@xxxxxxxxxx> wrote:
>
> Check if an optional reset gpio is present and if so, make sure to reset
> the device.
>
Just one note/question inline.
> Signed-off-by: Nuno Sá <nuno.sa@xxxxxxxxxx>
> ---
> drivers/iio/temperature/ltc2983.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/drivers/iio/temperature/ltc2983.c b/drivers/iio/temperature/ltc2983.c
> index 3b4a0e60e605..37903e9fb90f 100644
> --- a/drivers/iio/temperature/ltc2983.c
> +++ b/drivers/iio/temperature/ltc2983.c
> @@ -1470,6 +1470,7 @@ static int ltc2983_probe(struct spi_device *spi)
> {
> struct ltc2983_data *st;
> struct iio_dev *indio_dev;
> + struct gpio_desc *gpio;
> const char *name = spi_get_device_id(spi)->name;
> int ret;
>
> @@ -1494,6 +1495,16 @@ static int ltc2983_probe(struct spi_device *spi)
> if (ret)
> return ret;
>
> + gpio = devm_gpiod_get_optional(&st->spi->dev, "reset", GPIOD_OUT_HIGH);
> + if (IS_ERR(gpio))
> + return PTR_ERR(gpio);
> +
> + if (gpio) {
> + /* bring device out of reset */
> + usleep_range(1000, 1005);
> + gpiod_set_value_cansleep(gpio, 0);
Datasheet mentions that it takes up to 100 ms for the device to fully start-up.
It also mentions that the (command) status register will be
unavailable to the user before this point.
Page 16, Conversion State Details section, second paragraph.
I think there should probably be a sleep here of 100 ms.
Other than that change looks good.
> + }
> +
> ret = ltc2983_setup(st, true);
> if (ret)
> return ret;
> --
> 2.33.0
>
