| Message ID | 1432886754-30115-4-git-send-email-bhuvanchandra.dv@toradex.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, 29 May 2015 13:35:54 +0530, Bhuvanchandra DV wrote: > Enable Vybrid's build-in support for RS-485 auto RTS for > controlling line direction of RS-485 transceiver driver. > > Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com> > --- > drivers/tty/serial/fsl_lpuart.c | 60 +++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 60 insertions(+) > > diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c > index 357f623..c553b14 100644 > --- a/drivers/tty/serial/fsl_lpuart.c > +++ b/drivers/tty/serial/fsl_lpuart.c > @@ -820,6 +820,50 @@ static unsigned int lpuart32_tx_empty(struct uart_port *port) > TIOCSER_TEMT : 0; > } > > +static int lpuart_config_rs485(struct uart_port *port, > + struct serial_rs485 *rs485) > +{ > + struct lpuart_port *sport = container_of(port, > + struct lpuart_port, port); > + u8 modem = readb(sport->port.membase + UARTMODEM) & > + ~(UARTMODEM_TXRTSPOL | UARTMODEM_TXRTSE); Please put empty line between variables and code. > + writeb(modem, sport->port.membase + UARTMODEM); > + > + if (rs485->flags & SER_RS485_ENABLED) { > + /* Enable auto RS-485 RTS mode */ > + modem |= UARTMODEM_TXRTSE; > + > + /* > + * RTS needs to be logic HIGH either during transer _or_ after > + * transfer, other variants are not supported by the hardware. > + */ Indentation is off here. '*' should be aligned. > + if (!(rs485->flags & (SER_RS485_RTS_ON_SEND | > + SER_RS485_RTS_AFTER_SEND))) and here - things should be aligned on the containing bracket (SER_ under SER_ here). > + rs485->flags |= SER_RS485_RTS_ON_SEND; > + > + if (rs485->flags & SER_RS485_RTS_ON_SEND && > + rs485->flags & SER_RS485_RTS_AFTER_SEND) and here - same bracket rule (rs485-> under rs485->) > + rs485->flags &= ~SER_RS485_RTS_AFTER_SEND; > + > + /* > + * The hardware defaults to RTS logic HIGH while transfer. > + * Switch polarity in case RTS shall be logic HIGH > + * after transfer. > + * Note: UART is assumed to be active high. > + */ > + if (rs485->flags & SER_RS485_RTS_ON_SEND) > + modem &= ~UARTMODEM_TXRTSPOL; UARTMODEM_TXRTSPOL was already clear when you read modem. > + else if (rs485->flags & SER_RS485_RTS_AFTER_SEND) > + modem |= UARTMODEM_TXRTSPOL; > + } > + > + /* Store the new configuration */ > + sport->port.rs485 = *rs485; > + > + writeb(modem, sport->port.membase + UARTMODEM); > + return 0; > +} > + > static unsigned int lpuart_get_mctrl(struct uart_port *port) > { > return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR; [...] > @@ -1802,6 +1854,14 @@ static int lpuart_probe(struct platform_device *pdev) > dev_info(sport->port.dev, "DMA rx channel request failed, " > "operating without rx DMA\n"); > > + if (of_property_read_bool(np, "linux,rs485-enabled-at-boot-time")) { > + sport->port.rs485.flags |= SER_RS485_ENABLED; > + sport->port.rs485.flags |= SER_RS485_RTS_ON_SEND; > + writeb(UARTMODEM_TXRTSE, sport->port.membase + UARTMODEM); > + } else { > + sport->port.rs485.flags &= ~SER_RS485_ENABLED; Why the need to clear the flag? sport was kzalloc'ed.
On 05/29/2015 03:48 PM, Jakub Kici?ski wrote: > On Fri, 29 May 2015 13:35:54 +0530, Bhuvanchandra DV wrote: >> Enable Vybrid's build-in support for RS-485 auto RTS for >> controlling line direction of RS-485 transceiver driver. >> >> Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com> >> --- >> drivers/tty/serial/fsl_lpuart.c | 60 +++++++++++++++++++++++++++++++++++++++++ >> 1 file changed, 60 insertions(+) >> >> diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c >> index 357f623..c553b14 100644 >> --- a/drivers/tty/serial/fsl_lpuart.c >> +++ b/drivers/tty/serial/fsl_lpuart.c >> @@ -820,6 +820,50 @@ static unsigned int lpuart32_tx_empty(struct uart_port *port) >> TIOCSER_TEMT : 0; >> } >> >> +static int lpuart_config_rs485(struct uart_port *port, >> + struct serial_rs485 *rs485) >> +{ >> + struct lpuart_port *sport = container_of(port, >> + struct lpuart_port, port); >> + u8 modem = readb(sport->port.membase + UARTMODEM) & >> + ~(UARTMODEM_TXRTSPOL | UARTMODEM_TXRTSE); > > Please put empty line between variables and code. Ok > >> + writeb(modem, sport->port.membase + UARTMODEM); >> + >> + if (rs485->flags & SER_RS485_ENABLED) { >> + /* Enable auto RS-485 RTS mode */ >> + modem |= UARTMODEM_TXRTSE; >> + >> + /* >> + * RTS needs to be logic HIGH either during transer _or_ after >> + * transfer, other variants are not supported by the hardware. >> + */ > > Indentation is off here. '*' should be aligned. Ok > >> + if (!(rs485->flags & (SER_RS485_RTS_ON_SEND | >> + SER_RS485_RTS_AFTER_SEND))) > > and here - things should be aligned on the containing bracket (SER_ > under SER_ here). Ok > >> + rs485->flags |= SER_RS485_RTS_ON_SEND; >> + >> + if (rs485->flags & SER_RS485_RTS_ON_SEND && >> + rs485->flags & SER_RS485_RTS_AFTER_SEND) > > and here - same bracket rule (rs485-> under rs485->) Ok > >> + rs485->flags &= ~SER_RS485_RTS_AFTER_SEND; >> + >> + /* >> + * The hardware defaults to RTS logic HIGH while transfer. >> + * Switch polarity in case RTS shall be logic HIGH >> + * after transfer. >> + * Note: UART is assumed to be active high. >> + */ >> + if (rs485->flags & SER_RS485_RTS_ON_SEND) >> + modem &= ~UARTMODEM_TXRTSPOL; > > UARTMODEM_TXRTSPOL was already clear when you read modem. Ok > >> + else if (rs485->flags & SER_RS485_RTS_AFTER_SEND) >> + modem |= UARTMODEM_TXRTSPOL; >> + } >> + >> + /* Store the new configuration */ >> + sport->port.rs485 = *rs485; >> + >> + writeb(modem, sport->port.membase + UARTMODEM); >> + return 0; >> +} >> + >> static unsigned int lpuart_get_mctrl(struct uart_port *port) >> { >> return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR; > [...] >> @@ -1802,6 +1854,14 @@ static int lpuart_probe(struct platform_device *pdev) >> dev_info(sport->port.dev, "DMA rx channel request failed, " >> "operating without rx DMA\n"); >> >> + if (of_property_read_bool(np, "linux,rs485-enabled-at-boot-time")) { >> + sport->port.rs485.flags |= SER_RS485_ENABLED; >> + sport->port.rs485.flags |= SER_RS485_RTS_ON_SEND; >> + writeb(UARTMODEM_TXRTSE, sport->port.membase + UARTMODEM); >> + } else { >> + sport->port.rs485.flags &= ~SER_RS485_ENABLED; > > Why the need to clear the flag? sport was kzalloc'ed. Will remove it. > Best Regards, Bhuvan
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index 357f623..c553b14 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -820,6 +820,50 @@ static unsigned int lpuart32_tx_empty(struct uart_port *port) TIOCSER_TEMT : 0; } +static int lpuart_config_rs485(struct uart_port *port, + struct serial_rs485 *rs485) +{ + struct lpuart_port *sport = container_of(port, + struct lpuart_port, port); + u8 modem = readb(sport->port.membase + UARTMODEM) & + ~(UARTMODEM_TXRTSPOL | UARTMODEM_TXRTSE); + writeb(modem, sport->port.membase + UARTMODEM); + + if (rs485->flags & SER_RS485_ENABLED) { + /* Enable auto RS-485 RTS mode */ + modem |= UARTMODEM_TXRTSE; + + /* + * RTS needs to be logic HIGH either during transer _or_ after + * transfer, other variants are not supported by the hardware. + */ + if (!(rs485->flags & (SER_RS485_RTS_ON_SEND | + SER_RS485_RTS_AFTER_SEND))) + rs485->flags |= SER_RS485_RTS_ON_SEND; + + if (rs485->flags & SER_RS485_RTS_ON_SEND && + rs485->flags & SER_RS485_RTS_AFTER_SEND) + rs485->flags &= ~SER_RS485_RTS_AFTER_SEND; + + /* + * The hardware defaults to RTS logic HIGH while transfer. + * Switch polarity in case RTS shall be logic HIGH + * after transfer. + * Note: UART is assumed to be active high. + */ + if (rs485->flags & SER_RS485_RTS_ON_SEND) + modem &= ~UARTMODEM_TXRTSPOL; + else if (rs485->flags & SER_RS485_RTS_AFTER_SEND) + modem |= UARTMODEM_TXRTSPOL; + } + + /* Store the new configuration */ + sport->port.rs485 = *rs485; + + writeb(modem, sport->port.membase + UARTMODEM); + return 0; +} + static unsigned int lpuart_get_mctrl(struct uart_port *port) { return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR; @@ -1204,6 +1248,12 @@ lpuart_set_termios(struct uart_port *port, struct ktermios *termios, cr1 |= UARTCR1_M; } + /* When auto RS-485 RTS mode is enabled, + * hardware flow control need to be disabled. + */ + if (sport->port.rs485.flags & SER_RS485_ENABLED) + termios->c_cflag &= ~CRTSCTS; + if (termios->c_cflag & CRTSCTS) { modem |= (UARTMODEM_RXRTSE | UARTMODEM_TXCTSE); } else { @@ -1762,6 +1812,8 @@ static int lpuart_probe(struct platform_device *pdev) sport->port.ops = &lpuart_pops; sport->port.flags = UPF_BOOT_AUTOCONF; + sport->port.rs485_config = lpuart_config_rs485; + sport->clk = devm_clk_get(&pdev->dev, "ipg"); if (IS_ERR(sport->clk)) { ret = PTR_ERR(sport->clk); @@ -1802,6 +1854,14 @@ static int lpuart_probe(struct platform_device *pdev) dev_info(sport->port.dev, "DMA rx channel request failed, " "operating without rx DMA\n"); + if (of_property_read_bool(np, "linux,rs485-enabled-at-boot-time")) { + sport->port.rs485.flags |= SER_RS485_ENABLED; + sport->port.rs485.flags |= SER_RS485_RTS_ON_SEND; + writeb(UARTMODEM_TXRTSE, sport->port.membase + UARTMODEM); + } else { + sport->port.rs485.flags &= ~SER_RS485_ENABLED; + } + return 0; }
Enable Vybrid's build-in support for RS-485 auto RTS for controlling line direction of RS-485 transceiver driver. Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com> --- drivers/tty/serial/fsl_lpuart.c | 60 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 60 insertions(+)