Add an else-if condition in the probe function to check whether ngpios is multiple of 8. Per AST datasheet, numbers of available serial GPIO pins in Serial GPIO Configuration Register must be n bytes. For instance, if n = 1, it means AST SoC supports 8 GPIO pins. Signed-off-by: Steven Lee <steven_lee@xxxxxxxxxxxxxx> --- drivers/gpio/gpio-aspeed-sgpio.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpio/gpio-aspeed-sgpio.c b/drivers/gpio/gpio-aspeed-sgpio.c index f1e40486d401..1a3fcc721664 100644 --- a/drivers/gpio/gpio-aspeed-sgpio.c +++ b/drivers/gpio/gpio-aspeed-sgpio.c @@ -572,6 +572,10 @@ static int __init aspeed_sgpio_probe(struct platform_device *pdev) dev_err(&pdev->dev, "Number of GPIOs exceeds the maximum of %d: %d\n", gpio->max_ngpios, nr_gpios); return -EINVAL; + } else if (nr_gpios % 8) { + dev_err(&pdev->dev, "Number of GPIOs not multiple of 8: %d\n", + nr_gpios); + return -EINVAL; } gpio->n_sgpio = nr_gpios; -- 2.17.1