Commit 3ee07964 authored by Jiri Slaby (SUSE)'s avatar Jiri Slaby (SUSE) Committed by Greg Kroah-Hartman
Browse files

serial: core: introduce uart_port_tx_flags() 



And an enum with a flag: UART_TX_NOSTOP. To NOT call
__port->ops->stop_tx() when the circular buffer is empty. mxs-uart needs
this (see the next patch).

Signed-off-by: default avatar"Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: stable <stable@kernel.org>
Tested-by: default avatarEmil Kronborg <emil.kronborg@protonmail.com>
Link: https://lore.kernel.org/r/20240201105557.28043-1-jirislaby@kernel.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 720e78d7

include/linux/serial_core.h

+27 −5
Original line number Diff line number Diff line
@@ -748,8 +748,17 @@ struct uart_driver { 


void uart_write_wakeup(struct uart_port *port);



#define __uart_port_tx(uport, ch, tx_ready, put_char, tx_done, for_test,      \

		for_post)						      \

/**

 * enum UART_TX_FLAGS -- flags for uart_port_tx_flags()

 *

 * @UART_TX_NOSTOP: don't call port->ops->stop_tx() on empty buffer

 */

enum UART_TX_FLAGS {

	UART_TX_NOSTOP = BIT(0),

};



#define __uart_port_tx(uport, ch, flags, tx_ready, put_char, tx_done,	      \

		       for_test, for_post)				      \

({									      \

	struct uart_port *__port = (uport);				      \

	struct circ_buf *xmit = &__port->state->xmit;			      \
@@ -777,7 +786,7 @@ void uart_write_wakeup(struct uart_port *port); 
	if (pending < WAKEUP_CHARS) {					      \

		uart_write_wakeup(__port);				      \

									      \

		if (pending == 0)					      \

		if (!((flags) & UART_TX_NOSTOP) && pending == 0)	      \

			__port->ops->stop_tx(__port);			      \

	}								      \

									      \
@@ -812,7 +821,7 @@ void uart_write_wakeup(struct uart_port *port); 
 */

#define uart_port_tx_limited(port, ch, count, tx_ready, put_char, tx_done) ({ \

	unsigned int __count = (count);					      \

	__uart_port_tx(port, ch, tx_ready, put_char, tx_done, __count,	      \

	__uart_port_tx(port, ch, 0, tx_ready, put_char, tx_done, __count,     \

			__count--);					      \

})
@@ -826,8 +835,21 @@ void uart_write_wakeup(struct uart_port *port); 
 * See uart_port_tx_limited() for more details.

 */

#define uart_port_tx(port, ch, tx_ready, put_char)			\

	__uart_port_tx(port, ch, tx_ready, put_char, ({}), true, ({}))

	__uart_port_tx(port, ch, 0, tx_ready, put_char, ({}), true, ({}))





/**

 * uart_port_tx_flags -- transmit helper for uart_port with flags

 * @port: uart port

 * @ch: variable to store a character to be written to the HW

 * @flags: %UART_TX_NOSTOP or similar

 * @tx_ready: can HW accept more data function

 * @put_char: function to write a character

 *

 * See uart_port_tx_limited() for more details.

 */

#define uart_port_tx_flags(port, ch, flags, tx_ready, put_char)		\

	__uart_port_tx(port, ch, flags, tx_ready, put_char, ({}), true, ({}))

/*

 * Baud rate helpers.

 */