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| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-04-17 16:34:13 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-11-04 11:25:54 +0000 |
| commit | 2cbacafd7af0f1cc7a433668c662a91ba6aabc1b (patch) | |
| tree | be2e5735b395cba0bfcaf89c312a3fbdce7b05c3 | |
| parent | dec94e70e12c39440e63159e0050d46795dfcf09 (diff) | |
| download | linux-2cbacafd7af0f1cc7a433668c662a91ba6aabc1b.tar.gz linux-2cbacafd7af0f1cc7a433668c662a91ba6aabc1b.tar.bz2 linux-2cbacafd7af0f1cc7a433668c662a91ba6aabc1b.zip | |
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>
| -rw-r--r-- | drivers/tty/serial/serial_core.c | 16 | ||||
| -rw-r--r-- | include/linux/serial_core.h | 2 |
2 files changed, 16 insertions, 2 deletions
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index bc2065d323b9..bd10bbd56446 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -1213,7 +1213,19 @@ static void uart_set_termios(struct tty_struct *tty, struct uart_port *uport = state->uart_port; unsigned long flags; unsigned int cflag = tty->termios.c_cflag; + unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK; + bool sw_changed = false; + /* + * Drivers doing software flow control also need to know + * about changes to these input settings. + */ + if (uport->flags & UPF_SOFT_FLOW) { + iflag_mask |= IXANY|IXON|IXOFF; + sw_changed = + tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] || + tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP]; + } /* * These are the bits that are used to setup various @@ -1221,11 +1233,11 @@ static void uart_set_termios(struct tty_struct *tty, * bits in c_cflag; c_[io]speed will always be set * appropriately by set_termios() in tty_ioctl.c */ -#define RELEVANT_IFLAG(iflag) ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK)) if ((cflag ^ old_termios->c_cflag) == 0 && tty->termios.c_ospeed == old_termios->c_ospeed && tty->termios.c_ispeed == old_termios->c_ispeed && - RELEVANT_IFLAG(tty->termios.c_iflag ^ old_termios->c_iflag) == 0) { + ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 && + !sw_changed) { return; } 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)) |