It's possible that PCI device can provide an IO port resource for the device. regmap MMIO currently uses MMIO by default. With an additional flag we enable support for IO port accesses. Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> --- drivers/gpio/gpio-exar.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpio/gpio-exar.c b/drivers/gpio/gpio-exar.c index 482f678c893e..df1bdaae441c 100644 --- a/drivers/gpio/gpio-exar.c +++ b/drivers/gpio/gpio-exar.c @@ -141,6 +141,7 @@ static const struct regmap_config exar_regmap_config = { .name = "exar-gpio", .reg_bits = 16, .val_bits = 8, + .io_port = true, }; static int gpio_exar_probe(struct platform_device *pdev) -- 2.35.1