In some APIs we would like to assign the special value to iotype
and compare against it in another places. Introduce UPIO_UNKNOWN
for this purpose.
Note, we can't use 0, because it's a valid value for IO port access.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
include/linux/serial_core.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 2d2ec99eca93..c2cf9484014c 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -470,6 +470,7 @@ struct uart_port {
unsigned char iotype; /* io access style */
+#define UPIO_UNKNOWN ((unsigned char)~0U) /* UCHAR_MAX */
#define UPIO_PORT (SERIAL_IO_PORT) /* 8b I/O port access */
#define UPIO_HUB6 (SERIAL_IO_HUB6) /* Hub6 ISA card */
#define UPIO_MEM (SERIAL_IO_MEM) /* driver-specific */
--
2.43.0.rc1.1.gbec44491f096
