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author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-12-12 07:45:16 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-12-12 07:45:16 -0800 |
commit | d07e43d70eef15a44a2c328a913d8d633a90e088 (patch) | |
tree | 7a7cac7c90f4b8f19edfb2aecfa27d77e266eafc /drivers/tty/serial/serial_core.c | |
parent | 1ebaf4f4e6912199f8a4e30ba3ab55da2b71bcdf (diff) | |
parent | 3af08bd7adb09b0806c51c06b87db08cc7075568 (diff) | |
download | lwn-d07e43d70eef15a44a2c328a913d8d633a90e088.tar.gz lwn-d07e43d70eef15a44a2c328a913d8d633a90e088.zip |
Merge branch 'omap-serial' of git://git.linaro.org/people/rmk/linux-arm
Pull ARM OMAP serial updates from Russell King:
"This series is a major reworking of the OMAP serial driver code fixing
various bugs in the hardware-assisted flow control, extending up into
serial_core for a couple of issues. These fixes have been done as a
set of progressive changes and transformations in the hope that no new
bugs will be introduced by this series.
The problems are many-fold, from the driver not being informed about
updated settings, to the driver not knowing what the intentions of the
upper layers are.
The first four patches tackle the serial_core layer, allowing it to
provide the necessary information to drivers, and the remaining
patches allow the OMAP serial driver to take advantage of this.
This brings hardware assisted RTS/CTS and XON/OFF flow control into a
useful state.
These patches have been in linux-next for most of the last cycle;
indeed they predate the previous merge window. They've also been
posted to the OMAP people."
* 'omap-serial' of git://git.linaro.org/people/rmk/linux-arm: (21 commits)
SERIAL: omap: fix hardware assisted flow control
SERIAL: omap: simplify (2)
SERIAL: omap: move xon/xoff setting earlier
SERIAL: omap: always set TCR
SERIAL: omap: simplify
SERIAL: omap: don't read back LCR/MCR/EFR
SERIAL: omap: serial_omap_configure_xonxoff() contents into set_termios
SERIAL: omap: configure xon/xoff before setting modem control lines
SERIAL: omap: remove OMAP_UART_SYSC_RESET and OMAP_UART_FIFO_CLR
SERIAL: omap: move driver private definitions and structures to driver
SERIAL: omap: remove 'irq_pending' bitfield
SERIAL: omap: fix MCR TCRTLR bit handling
SERIAL: omap: fix set_mctrl() breakage
SERIAL: omap: no need to re-read EFR
SERIAL: omap: remove setting of EFR SCD bit
SERIAL: omap: allow hardware assisted IXANY mode to be disabled
SERIAL: omap: allow hardware assisted rts/cts modes to be disabled
SERIAL: core: add throttle/unthrottle callbacks for hardware assisted flow control
SERIAL: core: add hardware assisted h/w flow control support
SERIAL: core: add hardware assisted s/w flow control support
...
Conflicts:
drivers/tty/serial/omap-serial.c
Diffstat (limited to 'drivers/tty/serial/serial_core.c')
-rw-r--r-- | drivers/tty/serial/serial_core.c | 71 |
1 files changed, 57 insertions, 14 deletions
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index fb5aa42fde7e..2c7230aaefd4 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -610,27 +610,50 @@ static void uart_send_xchar(struct tty_struct *tty, char ch) static void uart_throttle(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; + struct uart_port *port = state->uart_port; + uint32_t mask = 0; if (I_IXOFF(tty)) + mask |= UPF_SOFT_FLOW; + if (tty->termios.c_cflag & CRTSCTS) + mask |= UPF_HARD_FLOW; + + if (port->flags & mask) { + port->ops->throttle(port); + mask &= ~port->flags; + } + + if (mask & UPF_SOFT_FLOW) uart_send_xchar(tty, STOP_CHAR(tty)); - if (tty->termios.c_cflag & CRTSCTS) - uart_clear_mctrl(state->uart_port, TIOCM_RTS); + if (mask & UPF_HARD_FLOW) + uart_clear_mctrl(port, TIOCM_RTS); } static void uart_unthrottle(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; struct uart_port *port = state->uart_port; + uint32_t mask = 0; - if (I_IXOFF(tty)) { + if (I_IXOFF(tty)) + mask |= UPF_SOFT_FLOW; + if (tty->termios.c_cflag & CRTSCTS) + mask |= UPF_HARD_FLOW; + + if (port->flags & mask) { + port->ops->unthrottle(port); + mask &= ~port->flags; + } + + if (mask & UPF_SOFT_FLOW) { if (port->x_char) port->x_char = 0; else uart_send_xchar(tty, START_CHAR(tty)); } - if (tty->termios.c_cflag & CRTSCTS) + if (mask & UPF_HARD_FLOW) uart_set_mctrl(port, TIOCM_RTS); } @@ -1214,9 +1237,22 @@ static void uart_set_termios(struct tty_struct *tty, struct ktermios *old_termios) { struct uart_state *state = tty->driver_data; + 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 @@ -1224,11 +1260,11 @@ 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; } @@ -1236,31 +1272,38 @@ static void uart_set_termios(struct tty_struct *tty, /* Handle transition to B0 status */ if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD)) - uart_clear_mctrl(state->uart_port, TIOCM_RTS | TIOCM_DTR); + uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR); /* Handle transition away from B0 status */ else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) { unsigned int mask = TIOCM_DTR; if (!(cflag & CRTSCTS) || !test_bit(TTY_THROTTLED, &tty->flags)) mask |= TIOCM_RTS; - uart_set_mctrl(state->uart_port, mask); + uart_set_mctrl(uport, mask); } + /* + * If the port is doing h/w assisted flow control, do nothing. + * We assume that tty->hw_stopped has never been set. + */ + if (uport->flags & UPF_HARD_FLOW) + return; + /* Handle turning off CRTSCTS */ if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) { - spin_lock_irqsave(&state->uart_port->lock, flags); + spin_lock_irqsave(&uport->lock, flags); tty->hw_stopped = 0; __uart_start(tty); - spin_unlock_irqrestore(&state->uart_port->lock, flags); + spin_unlock_irqrestore(&uport->lock, flags); } /* Handle turning on CRTSCTS */ else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) { - spin_lock_irqsave(&state->uart_port->lock, flags); - if (!(state->uart_port->ops->get_mctrl(state->uart_port) & TIOCM_CTS)) { + spin_lock_irqsave(&uport->lock, flags); + if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS)) { tty->hw_stopped = 1; - state->uart_port->ops->stop_tx(state->uart_port); + uport->ops->stop_tx(uport); } - spin_unlock_irqrestore(&state->uart_port->lock, flags); + spin_unlock_irqrestore(&uport->lock, flags); } } |