Messages in this thread Patch in this message | | | Date | Tue, 23 Aug 2011 10:30:46 +0200 | From | Claudio Scordino <> | Subject | Re: [PATCH] atmel_serial: RS485: receiving enabled when sending data |
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Il 22/08/2011 23:18, Greg KH ha scritto: > On Mon, Aug 15, 2011 at 04:28:15PM +0200, Bernhard Roth wrote: >> Hello! >> >> By default the atmel_serial driver in RS485 mode disables receiving >> data until all data in the send buffer has been sent. This flag >> allows to receive data even whilst sending data. This is very useful >> to >> >> - check if the data has been sent correctly over the RS485 bus >> - assure that no collision happened >> - check for short circuits/termination issues on the RS485 bus >> >> Usually this functionality is realized by hardware, wether >> controlling the RX-Enable pin of the RS485 transceiver with RTS >> (driver control signal) or pulling it LOW permanently. The present >> atmel_serial driver makes this impossible, thus requiring following >> patch. >> >> Usage example: >> >> struct serial_rs485 rs485; >> >> memset(&rs485, 0, sizeof(rs485)); >> rs485.flags = SER_RS485_ENABLED | SER_RS485_RX_DURING_TX; >> ioctl(fd, TIOCSRS485,&rs485); >> >> >> >> >> atmel_serial: RS485: receiving enabled when sending data >> >> By default the atmel_serial driver in RS485 mode disables receiving >> data until >> all data in the send buffer has been sent. This flag allows to receive data >> even whilst sending data. >> >> Signed-off-by: Bernhard Roth<br@pwrnet.de> >> Signed-off-by: Claudio Scordino<claudio@evidence.eu.com> >> --- >> drivers/tty/serial/atmel_serial.c | 17 ++++++++++------- >> include/linux/serial.h | 1 + >> 2 files changed, 11 insertions(+), 7 deletions(-) >> >> diff --git a/drivers/tty/serial/atmel_serial.c >> b/drivers/tty/serial/atmel_serial.c >> index af9b781..5f6c745 100644 >> --- a/drivers/tty/serial/atmel_serial.c >> +++ b/drivers/tty/serial/atmel_serial.c >> @@ -339,8 +339,9 @@ static void atmel_stop_tx(struct uart_port *port) >> /* Disable interrupts */ >> UART_PUT_IDR(port, atmel_port->tx_done_mask); >> >> - if (atmel_port->rs485.flags& SER_RS485_ENABLED) >> - atmel_start_rx(port); >> + if ((atmel_port->rs485.flags& SER_RS485_ENABLED)&& >> + !(atmel_port->rs485.flags& SER_RS485_RX_DURING_TX)) >> + atmel_start_rx(port); > > Can you fix your email client to not strip patches of tabs and resend > this so that I can apply it? > > thanks, > > greg k-h
Hi Greg,
please find below the patch with the right tabs.
Remind however that the main author of the patch is Bernhard, not me.
Best regards,
Claudio
atmel_serial: RS485: receiving enabled when sending data
By default the atmel_serial driver in RS485 mode disables receiving data until all data in the send buffer has been sent. This flag allows to receive data even whilst sending data.
Signed-off-by: Bernhard Roth <br@pwrnet.de> Signed-off-by: Claudio Scordino <claudio@evidence.eu.com> --- drivers/tty/serial/atmel_serial.c | 17 ++++++++++------- include/linux/serial.h | 1 + 2 files changed, 11 insertions(+), 7 deletions(-)
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index af9b781..5f6c745 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -339,8 +339,9 @@ static void atmel_stop_tx(struct uart_port *port) /* Disable interrupts */ UART_PUT_IDR(port, atmel_port->tx_done_mask); - if (atmel_port->rs485.flags & SER_RS485_ENABLED) - atmel_start_rx(port); + if ((atmel_port->rs485.flags & SER_RS485_ENABLED) && + !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX)) + atmel_start_rx(port); } /* @@ -356,8 +357,9 @@ static void atmel_start_tx(struct uart_port *port) really need this.*/ return; - if (atmel_port->rs485.flags & SER_RS485_ENABLED) - atmel_stop_rx(port); + if ((atmel_port->rs485.flags & SER_RS485_ENABLED) && + !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX)) + atmel_stop_rx(port); /* re-enable PDC transmit */ UART_PUT_PTCR(port, ATMEL_PDC_TXTEN); @@ -680,9 +682,10 @@ static void atmel_tx_dma(struct uart_port *port) /* Enable interrupts */ UART_PUT_IER(port, atmel_port->tx_done_mask); } else { - if (atmel_port->rs485.flags & SER_RS485_ENABLED) { - /* DMA done, stop TX, start RX for RS485 */ - atmel_start_rx(port); + if ((atmel_port->rs485.flags & SER_RS485_ENABLED) && + !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX)) { + /* DMA done, stop TX, start RX for RS485 */ + atmel_start_rx(port); } } diff --git a/include/linux/serial.h b/include/linux/serial.h index ef91406..97ff8e2 100644 --- a/include/linux/serial.h +++ b/include/linux/serial.h @@ -211,6 +211,7 @@ struct serial_rs485 { #define SER_RS485_RTS_ON_SEND (1 << 1) #define SER_RS485_RTS_AFTER_SEND (1 << 2) #define SER_RS485_RTS_BEFORE_SEND (1 << 3) +#define SER_RS485_RX_DURING_TX (1 << 4) __u32 delay_rts_before_send; /* Milliseconds */ __u32 delay_rts_after_send; /* Milliseconds */ __u32 padding[5]; /* Memory is cheap, new structs -- 1.7.1
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