Commit d11cc8c3 authored by Jiri Slaby (SUSE)'s avatar Jiri Slaby (SUSE) Committed by Greg Kroah-Hartman
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tty: serial: use uart_port_tx_limited() 



uart_port_tx_limited() is a new helper to send characters to the device.
Use it in these drivers.

mux.c also needs to define tx_done(). But I'm not sure if the driver
really wants to wait for all the characters to dismiss from the HW fifo
at this code point. Hence I marked this as FIXME.

Cc: Russell King <linux@armlinux.org.uk>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: "Pali Rohár" <pali@kernel.org>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Orson Zhai <orsonzhai@gmail.com>
Cc: Baolin Wang <baolin.wang7@gmail.com>
Cc: Chunyan Zhang <zhang.lyra@gmail.com>
Cc: Patrice Chotard <patrice.chotard@foss.st.com>
Cc: linux-riscv@lists.infradead.org
Reviewed-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: default avatarJiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20221004104927.14361-4-jirislaby@kernel.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 2d141e68

drivers/tty/serial/21285.c

+5 −27
Original line number Diff line number Diff line
@@ -154,35 +154,13 @@ static irqreturn_t serial21285_rx_chars(int irq, void *dev_id) 
static irqreturn_t serial21285_tx_chars(int irq, void *dev_id)

{

	struct uart_port *port = dev_id;

	struct circ_buf *xmit = &port->state->xmit;

	int count = 256;

	u8 ch;



	if (port->x_char) {

		*CSR_UARTDR = port->x_char;

		port->icount.tx++;

		port->x_char = 0;

		goto out;

	}

	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {

		serial21285_stop_tx(port);

		goto out;

	}



	do {

		*CSR_UARTDR = xmit->buf[xmit->tail];

		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);

		port->icount.tx++;

		if (uart_circ_empty(xmit))

			break;

	} while (--count > 0 && !(*CSR_UARTFLG & 0x20));



	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)

		uart_write_wakeup(port);



	if (uart_circ_empty(xmit))

		serial21285_stop_tx(port);

	uart_port_tx_limited(port, ch, 256,

		!(*CSR_UARTFLG & 0x20),

		*CSR_UARTDR = ch,

		({}));



 out:

	return IRQ_HANDLED;

}

drivers/tty/serial/altera_jtaguart.c

+7 −29
Original line number Diff line number Diff line
@@ -146,37 +146,15 @@ static void altera_jtaguart_rx_chars(struct altera_jtaguart *pp) 
static void altera_jtaguart_tx_chars(struct altera_jtaguart *pp)

{

	struct uart_port *port = &pp->port;

	struct circ_buf *xmit = &port->state->xmit;

	unsigned int pending, count;

	unsigned int count;

	u8 ch;



	if (port->x_char) {

		/* Send special char - probably flow control */

		writel(port->x_char, port->membase + ALTERA_JTAGUART_DATA_REG);

		port->x_char = 0;

		port->icount.tx++;

		return;

	}



	pending = uart_circ_chars_pending(xmit);

	if (pending > 0) {

	count = altera_jtaguart_tx_space(port, NULL);

		if (count > pending)

			count = pending;

		if (count > 0) {

			pending -= count;

			while (count--) {

				writel(xmit->buf[xmit->tail],

				       port->membase + ALTERA_JTAGUART_DATA_REG);

				xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);

				port->icount.tx++;

			}

			if (pending < WAKEUP_CHARS)

				uart_write_wakeup(port);

		}

	}



	if (pending == 0)

		altera_jtaguart_stop_tx(port);

	uart_port_tx_limited(port, ch, count,

		true,

		writel(ch, port->membase + ALTERA_JTAGUART_DATA_REG),

		({}));

}



static irqreturn_t altera_jtaguart_interrupt(int irq, void *data)

drivers/tty/serial/amba-pl010.c

+5 −27
Original line number Diff line number Diff line
@@ -164,34 +164,12 @@ static void pl010_rx_chars(struct uart_port *port) 


static void pl010_tx_chars(struct uart_port *port)

{

	struct circ_buf *xmit = &port->state->xmit;

	int count;

	u8 ch;



	if (port->x_char) {

		writel(port->x_char, port->membase + UART01x_DR);

		port->icount.tx++;

		port->x_char = 0;

		return;

	}

	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {

		pl010_stop_tx(port);

		return;

	}



	count = port->fifosize >> 1;

	do {

		writel(xmit->buf[xmit->tail], port->membase + UART01x_DR);

		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);

		port->icount.tx++;

		if (uart_circ_empty(xmit))

			break;

	} while (--count > 0);



	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)

		uart_write_wakeup(port);



	if (uart_circ_empty(xmit))

		pl010_stop_tx(port);

	uart_port_tx_limited(port, ch, port->fifosize >> 1,

		true,

		writel(ch, port->membase + UART01x_DR),

		({}));

}



static void pl010_modem_status(struct uart_amba_port *uap)

drivers/tty/serial/apbuart.c

+5 −29
Original line number Diff line number Diff line
@@ -122,36 +122,12 @@ static void apbuart_rx_chars(struct uart_port *port) 


static void apbuart_tx_chars(struct uart_port *port)

{

	struct circ_buf *xmit = &port->state->xmit;

	int count;

	u8 ch;



	if (port->x_char) {

		UART_PUT_CHAR(port, port->x_char);

		port->icount.tx++;

		port->x_char = 0;

		return;

	}



	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {

		apbuart_stop_tx(port);

		return;

	}



	/* amba: fill FIFO */

	count = port->fifosize >> 1;

	do {

		UART_PUT_CHAR(port, xmit->buf[xmit->tail]);

		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);

		port->icount.tx++;

		if (uart_circ_empty(xmit))

			break;

	} while (--count > 0);



	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)

		uart_write_wakeup(port);



	if (uart_circ_empty(xmit))

		apbuart_stop_tx(port);

	uart_port_tx_limited(port, ch, port->fifosize >> 1,

		true,

		UART_PUT_CHAR(port, ch),

		({}));

}



static irqreturn_t apbuart_int(int irq, void *dev_id)

drivers/tty/serial/bcm63xx_uart.c

+9 −38
Original line number Diff line number Diff line
@@ -303,53 +303,24 @@ static void bcm_uart_do_rx(struct uart_port *port) 
 */

static void bcm_uart_do_tx(struct uart_port *port)

{

	struct circ_buf *xmit;

	unsigned int val, max_count;



	if (port->x_char) {

		bcm_uart_writel(port, port->x_char, UART_FIFO_REG);

		port->icount.tx++;

		port->x_char = 0;

		return;

	}



	if (uart_tx_stopped(port)) {

		bcm_uart_stop_tx(port);

		return;

	}



	xmit = &port->state->xmit;

	if (uart_circ_empty(xmit))

		goto txq_empty;

	unsigned int val;

	bool pending;

	u8 ch;



	val = bcm_uart_readl(port, UART_MCTL_REG);

	val = (val & UART_MCTL_TXFIFOFILL_MASK) >> UART_MCTL_TXFIFOFILL_SHIFT;

	max_count = port->fifosize - val;



	while (max_count--) {

		unsigned int c;



		c = xmit->buf[xmit->tail];

		bcm_uart_writel(port, c, UART_FIFO_REG);

		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);

		port->icount.tx++;

		if (uart_circ_empty(xmit))

			break;

	}



	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)

		uart_write_wakeup(port);



	if (uart_circ_empty(xmit))

		goto txq_empty;

	pending = uart_port_tx_limited(port, ch, port->fifosize - val,

		true,

		bcm_uart_writel(port, ch, UART_FIFO_REG),

		({}));

	if (pending)

		return;



txq_empty:

	/* nothing to send, disable transmit interrupt */

	val = bcm_uart_readl(port, UART_IR_REG);

	val &= ~UART_TX_INT_MASK;

	bcm_uart_writel(port, val, UART_IR_REG);

	return;

}



/*