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]> --- 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
