This makes sense. I did have to fix up my user space app to set SER_RS485_RTS_ON_SEND after applying this patch.
On Mon, 16 Mar 2015, Jakub Kicinski wrote: > From: Jakub Kicinski <[email protected]> > > Hardware is capable of inverting RTS signal when working > in RS-485 mode. Expose this functionality to user space. > Relay on a matching combination of standard flags > (SER_RS485_RTS_ON_SEND and SER_RS485_RTS_AFTER_SEND) to > detect when user space is requesting inverted RTS mode. > > Signed-off-by: Jakub Kicinski <[email protected]> Signed-off-by: Jon Ringle <[email protected]> > --- > drivers/tty/serial/sc16is7xx.c | 32 +++++++++++++++++++++++--------- > 1 file changed, 23 insertions(+), 9 deletions(-) > > diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c > index e6b396e584f3..24902d589b07 100644 > --- a/drivers/tty/serial/sc16is7xx.c > +++ b/drivers/tty/serial/sc16is7xx.c > @@ -829,16 +829,30 @@ static void sc16is7xx_set_termios(struct uart_port > *port, > } > > static int sc16is7xx_config_rs485(struct uart_port *port, > - struct serial_rs485 *rs485) > + struct serial_rs485 *rs485) > { > - if (port->rs485.flags & SER_RS485_ENABLED) > - sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, > - SC16IS7XX_EFCR_AUTO_RS485_BIT, > - SC16IS7XX_EFCR_AUTO_RS485_BIT); > - else > - sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, > - SC16IS7XX_EFCR_AUTO_RS485_BIT, > - 0); > + const u32 mask = SC16IS7XX_EFCR_AUTO_RS485_BIT | > + SC16IS7XX_EFCR_RTS_INVERT_BIT; > + u32 efcr = 0; > + > + if (rs485->flags & SER_RS485_ENABLED) { > + bool rts_during_rx, rts_during_tx; > + > + rts_during_rx = rs485->flags & SER_RS485_RTS_AFTER_SEND; > + rts_during_tx = rs485->flags & SER_RS485_RTS_ON_SEND; > + > + efcr |= SC16IS7XX_EFCR_AUTO_RS485_BIT; > + > + if (!rts_during_rx && rts_during_tx) > + /* default */; > + else if (rts_during_rx && !rts_during_tx) > + efcr |= SC16IS7XX_EFCR_RTS_INVERT_BIT; > + else > + return -EINVAL; > + } > + > + sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, mask, efcr); > + > port->rs485 = *rs485; > > return 0; > -- > 2.1.0 > > -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
