| Message ID | 20240118074003.2334348-3-manikanta.guntupalli@amd.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add rs485 support to uartps driver | expand |
> -----Original Message----- > From: Manikanta Guntupalli <manikanta.guntupalli@amd.com> > Sent: Thursday, 18 January 2024 08:40 > Subject: [PATCH V9 2/3] tty: serial: uartps: Relocate cdns_uart_tx_empty to > facilitate rs485 > > Relocate cdns_uart_tx_empty function to avoid prototype statement in > rs485 changes. > Update return check with uart_tx_stopped() in cdns_uart_handle_tx(). > > Signed-off-by: Manikanta Guntupalli <manikanta.guntupalli@amd.com> > --- > Changes for V9: > Update return check with uart_tx_stopped() in cdns_uart_handle_tx(). > Update description of cdns_uart_handle_tx() and add clear TX Empty interrupt > comment cdns_uart_start_tx(). > --- > drivers/tty/serial/xilinx_uartps.c | 35 +++++++++++++++--------------- > 1 file changed, 18 insertions(+), 17 deletions(-) > > diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c > index 920762d7b4a4..787c7cbc6600 100644 > --- a/drivers/tty/serial/xilinx_uartps.c > +++ b/drivers/tty/serial/xilinx_uartps.c > @@ -316,7 +331,7 @@ static void cdns_uart_handle_tx(void *dev_id) > struct circ_buf *xmit = &port->state->xmit; > unsigned int numbytes; > > - if (uart_circ_empty(xmit)) { > + if (uart_circ_empty(xmit) || uart_tx_stopped(port)) { Can you please also insert a comment here? + /* Disable the TX Empty interrupt */ > writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_IDR); > return; > } Kind regards, Maarten Brock
> -----Original Message----- > From: Manikanta Guntupalli <manikanta.guntupalli@amd.com> > Sent: Thursday, 18 January 2024 08:40 > Subject: [PATCH V9 2/3] tty: serial: uartps: Relocate cdns_uart_tx_empty to > facilitate rs485 > > Relocate cdns_uart_tx_empty function to avoid prototype statement in > rs485 changes. > Update return check with uart_tx_stopped() in cdns_uart_handle_tx(). > > Signed-off-by: Manikanta Guntupalli <manikanta.guntupalli@amd.com> > --- > --- a/drivers/tty/serial/xilinx_uartps.c > +++ b/drivers/tty/serial/xilinx_uartps.c > @@ -316,7 +331,7 @@ static void cdns_uart_handle_tx(void *dev_id) > struct circ_buf *xmit = &port->state->xmit; > unsigned int numbytes; > > - if (uart_circ_empty(xmit)) { > + if (uart_circ_empty(xmit) || uart_tx_stopped(port)) { Can you please also insert a comment here? + /* Disable the TX Empty interrupt */ > writel(CDNS_UART_IXR_TXEMPTY, port->membase + > CDNS_UART_IDR); > return; > } Kind regards, Maarten Brock
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index 920762d7b4a4..787c7cbc6600 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -306,7 +306,22 @@ static void cdns_uart_handle_rx(void *dev_id, unsigned int isrstatus) } /** - * cdns_uart_handle_tx - Handle the bytes to be Txed. + * cdns_uart_tx_empty - Check whether TX is empty + * @port: Handle to the uart port structure + * + * Return: TIOCSER_TEMT on success, 0 otherwise + */ +static unsigned int cdns_uart_tx_empty(struct uart_port *port) +{ + unsigned int status; + + status = readl(port->membase + CDNS_UART_SR); + status &= (CDNS_UART_SR_TXEMPTY | CDNS_UART_SR_TACTIVE); + return (status == CDNS_UART_SR_TXEMPTY) ? TIOCSER_TEMT : 0; +} + +/** + * cdns_uart_handle_tx - Handle the bytes to be transmitted. * @dev_id: Id of the UART port * Return: None */ @@ -316,7 +331,7 @@ static void cdns_uart_handle_tx(void *dev_id) struct circ_buf *xmit = &port->state->xmit; unsigned int numbytes; - if (uart_circ_empty(xmit)) { + if (uart_circ_empty(xmit) || uart_tx_stopped(port)) { writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_IDR); return; } @@ -587,6 +602,7 @@ static void cdns_uart_start_tx(struct uart_port *port) if (uart_circ_empty(&port->state->xmit)) return; + /* Clear the TX Empty interrupt */ writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_ISR); cdns_uart_handle_tx(port); @@ -626,21 +642,6 @@ static void cdns_uart_stop_rx(struct uart_port *port) writel(regval, port->membase + CDNS_UART_CR); } -/** - * cdns_uart_tx_empty - Check whether TX is empty - * @port: Handle to the uart port structure - * - * Return: TIOCSER_TEMT on success, 0 otherwise - */ -static unsigned int cdns_uart_tx_empty(struct uart_port *port) -{ - unsigned int status; - - status = readl(port->membase + CDNS_UART_SR) & - (CDNS_UART_SR_TXEMPTY | CDNS_UART_SR_TACTIVE); - return (status == CDNS_UART_SR_TXEMPTY) ? TIOCSER_TEMT : 0; -} - /** * cdns_uart_break_ctl - Based on the input ctl we have to start or stop * transmitting char breaks
Relocate cdns_uart_tx_empty function to avoid prototype statement in rs485 changes. Update return check with uart_tx_stopped() in cdns_uart_handle_tx(). Signed-off-by: Manikanta Guntupalli <manikanta.guntupalli@amd.com> --- Changes since V4: This patch introduced in V4. Changes for V5: None. Changes for V6: None. Changes for V7: None. Changes for V8: None. Changes for V9: Update return check with uart_tx_stopped() in cdns_uart_handle_tx(). Update description of cdns_uart_handle_tx() and add clear TX Empty interrupt comment cdns_uart_start_tx(). --- drivers/tty/serial/xilinx_uartps.c | 35 +++++++++++++++--------------- 1 file changed, 18 insertions(+), 17 deletions(-)