Hi, On 20 September 2018 at 08:36, Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx> wrote: > Hi, > > On Mon, Sep 17, 2018 at 12:01:51PM +0800, Baolin Wang wrote: > [...] >> >> +static int sc27xx_fgu_parse_dt(struct sc27xx_fgu_data *data, >> >> + struct device_node *np) >> >> +{ >> >> + const __be32 *list; >> >> + int i, len, size, ret; >> >> + >> >> + ret = of_property_read_u32(np, "reg", &data->base); >> >> + if (ret) { >> >> + dev_err(data->dev, "failed to get fgu address\n"); >> >> + return ret; >> >> + } >> >> + >> >> + data->gpiod = devm_gpiod_get_optional(data->dev, "bat-detect", GPIOD_IN); >> >> + if (IS_ERR(data->gpiod)) { >> >> + dev_err(data->dev, "failed to get battery detection GPIO\n"); >> >> + return PTR_ERR(data->gpiod); >> >> + } >> > >> > According to the binding (and the remaining code!) this gpio is not >> > optional. >> >> Yes, they are not optional. If we can not get the detection GPIO, we >> will return errors. So am I missing something else? >> >> Thanks for your comments. > > devm_gpiod_get_optional => devm_gpiod_get > > The _optional variant will return NULL if the GPIO is not specified in DT. > The variant without _optional will return an error instead. Ah, you are definitely correct. I missed _optional and thanks for pointing this out. -- Baolin Wang Best Regards