SERIAL: core: add hardware assisted s/w flow control support

Ports which are capable of handling s/w flow control in hardware to
know when the s/w flow control termios settings are changed.  Add a
flag to allow the low level serial drivers to indicate that they
support this, and these changes should be propagated to them.

Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 3c430228d232..00051388de3c 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -163,6 +163,8 @@ struct uart_port {
 #define UPF_BUGGY_UART          ((__force upf_t) (1 << 14))
 #define UPF_NO_TXEN_TEST        ((__force upf_t) (1 << 15))
 #define UPF_MAGIC_MULTIPLIER    ((__force upf_t) (1 << 16))
+/* Port has hardware-assisted s/w flow control */
+#define UPF_SOFT_FLOW           ((__force upf_t) (1 << 22))
 #define UPF_CONS_FLOW           ((__force upf_t) (1 << 23))
 #define UPF_SHARE_IRQ           ((__force upf_t) (1 << 24))
 #define UPF_EXAR_EFR            ((__force upf_t) (1 << 25))