[PATCH v4 09/10] tty: serial: use uart_port_tx() helper

From: Jiri Slaby
Date: Tue Sep 20 2022 - 01:21:42 EST

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

Cc: Tobias Klauser <tklauser@xxxxxxxxxx>
Cc: Richard Genoud <richard.genoud@xxxxxxxxx>
Cc: Nicolas Ferre <nicolas.ferre@xxxxxxxxxxxxx>
Cc: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
Cc: Claudiu Beznea <claudiu.beznea@xxxxxxxxxxxxx>
Cc: Vladimir Zapolskiy <vz@xxxxxxxxx>
Cc: Liviu Dudau <liviu.dudau@xxxxxxx>
Cc: Sudeep Holla <sudeep.holla@xxxxxxx>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Cc: Shawn Guo <shawnguo@xxxxxxxxxx>
Cc: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
Cc: Pengutronix Kernel Team <kernel@xxxxxxxxxxxxxx>
Cc: Fabio Estevam <festevam@xxxxxxxxx>
Cc: NXP Linux Team <linux-imx@xxxxxxx>
Cc: "Andreas Färber" <afaerber@xxxxxxx>
Cc: Manivannan Sadhasivam <mani@xxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---

Notes:
[v4] switch from DEFINE_UART_PORT_TX_HELPER() (helper generator) to
uart_port_tx() (akin to wait_event())

[v3] remove stray \n removal (Ilpo)

drivers/tty/serial/altera_uart.c | 29 ++++------------------
drivers/tty/serial/atmel_serial.c | 28 +++++----------------
drivers/tty/serial/fsl_lpuart.c | 30 ++++-------------------
drivers/tty/serial/lantiq.c | 36 +++------------------------
drivers/tty/serial/lpc32xx_hs.c | 33 +++----------------------
drivers/tty/serial/mcf.c | 28 +++++----------------
drivers/tty/serial/mpc52xx_uart.c | 39 +++---------------------------
drivers/tty/serial/mps2-uart.c | 26 +++-----------------
drivers/tty/serial/mxs-auart.c | 32 ++++++------------------
drivers/tty/serial/owl-uart.c | 32 +++---------------------
drivers/tty/serial/sa1100.c | 34 +++-----------------------
drivers/tty/serial/vt8500_serial.c | 30 +++--------------------
12 files changed, 58 insertions(+), 319 deletions(-)

diff --git a/drivers/tty/serial/altera_uart.c b/drivers/tty/serial/altera_uart.c
index 82f2790de28d..316074bb23e9 100644
--- a/drivers/tty/serial/altera_uart.c
+++ b/drivers/tty/serial/altera_uart.c
@@ -247,31 +247,12 @@ static void altera_uart_rx_chars(struct uart_port *port)

static void altera_uart_tx_chars(struct uart_port *port)
{
- struct circ_buf *xmit = &port->state->xmit;
-
- if (port->x_char) {
- /* Send special char - probably flow control */
- altera_uart_writel(port, port->x_char, ALTERA_UART_TXDATA_REG);
- port->x_char = 0;
- port->icount.tx++;
- return;
- }
-
- while (altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
- ALTERA_UART_STATUS_TRDY_MSK) {
- if (xmit->head == xmit->tail)
- break;
- altera_uart_writel(port, xmit->buf[xmit->tail],
- ALTERA_UART_TXDATA_REG);
- xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
- port->icount.tx++;
- }
-
- if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
- uart_write_wakeup(port);
+ u8 ch;

- if (uart_circ_empty(xmit))
- altera_uart_stop_tx(port);
+ uart_port_tx(port, ch,
+ altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
+ ALTERA_UART_STATUS_TRDY_MSK,
+ altera_uart_writel(port, ch, ALTERA_UART_TXDATA_REG));
}

static irqreturn_t altera_uart_interrupt(int irq, void *data)
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index ab4a9dfae07d..0e2b59bec6ce 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -816,30 +816,14 @@ static void atmel_rx_chars(struct uart_port *port)
*/
static void atmel_tx_chars(struct uart_port *port)
{
- struct circ_buf *xmit = &port->state->xmit;
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+ bool pending;
+ u8 ch;

- if (port->x_char &&
- (atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_TXRDY)) {
- atmel_uart_write_char(port, port->x_char);
- port->icount.tx++;
- port->x_char = 0;
- }
- if (uart_circ_empty(xmit) || uart_tx_stopped(port))
- return;
-
- while (atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_TXRDY) {
- atmel_uart_write_char(port, xmit->buf[xmit->tail]);
- 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)) {
+ pending = uart_port_tx(port, ch,
+ atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_TXRDY,
+ atmel_uart_write_char(port, ch));
+ if (pending) {
/* we still have characters to transmit, so we should continue
* transmitting them when TX is ready, regardless of
* mode or duplexity
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index f21915015d67..e8a8c11b10a8 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -742,32 +742,12 @@ static int lpuart32_poll_get_char(struct uart_port *port)

static inline void lpuart_transmit_buffer(struct lpuart_port *sport)
{
- struct circ_buf *xmit = &sport->port.state->xmit;
-
- if (sport->port.x_char) {
- writeb(sport->port.x_char, sport->port.membase + UARTDR);
- sport->port.icount.tx++;
- sport->port.x_char = 0;
- return;
- }
-
- if (lpuart_stopped_or_empty(&sport->port)) {
- lpuart_stop_tx(&sport->port);
- return;
- }
-
- while (!uart_circ_empty(xmit) &&
- (readb(sport->port.membase + UARTTCFIFO) < sport->txfifo_size)) {
- writeb(xmit->buf[xmit->tail], sport->port.membase + UARTDR);
- xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
- sport->port.icount.tx++;
- }
-
- if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
- uart_write_wakeup(&sport->port);
+ struct uart_port *port = &sport->port;
+ u8 ch;

- if (uart_circ_empty(xmit))
- lpuart_stop_tx(&sport->port);
+ uart_port_tx(port, ch,
+ readb(port->membase + UARTTCFIFO) < sport->txfifo_size,
+ writeb(ch, port->membase + UARTDR));
}

static inline void lpuart32_transmit_buffer(struct lpuart_port *sport)
diff --git a/drivers/tty/serial/lantiq.c b/drivers/tty/serial/lantiq.c
index 6da1b7496c6c..06e813a232c5 100644
--- a/drivers/tty/serial/lantiq.c
+++ b/drivers/tty/serial/lantiq.c
@@ -95,7 +95,6 @@
#define ASCFSTAT_TXFREEMASK 0x3F000000
#define ASCFSTAT_TXFREEOFF 24

-static void lqasc_tx_chars(struct uart_port *port);
static struct ltq_uart_port *lqasc_port[MAXPORTS];
static struct uart_driver lqasc_reg;

@@ -151,9 +150,12 @@ lqasc_start_tx(struct uart_port *port)
{
unsigned long flags;
struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+ u8 ch;

spin_lock_irqsave(&ltq_port->lock, flags);
- lqasc_tx_chars(port);
+ uart_port_tx(port, ch,
+ lqasc_tx_ready(port),
+ writeb(ch, port->membase + LTQ_ASC_TBUF));
spin_unlock_irqrestore(&ltq_port->lock, flags);
return;
}
@@ -226,36 +228,6 @@ lqasc_rx_chars(struct uart_port *port)
return 0;
}

-static void
-lqasc_tx_chars(struct uart_port *port)
-{
- struct circ_buf *xmit = &port->state->xmit;
- if (uart_tx_stopped(port)) {
- lqasc_stop_tx(port);
- return;
- }
-
- while (lqasc_tx_ready(port)) {
- if (port->x_char) {
- writeb(port->x_char, port->membase + LTQ_ASC_TBUF);
- port->icount.tx++;
- port->x_char = 0;
- continue;
- }
-
- if (uart_circ_empty(xmit))
- break;
-
- writeb(port->state->xmit.buf[port->state->xmit.tail],
- port->membase + LTQ_ASC_TBUF);
- xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
- port->icount.tx++;
- }
-
- if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
- uart_write_wakeup(port);
-}
-
static irqreturn_t
lqasc_tx_int(int irq, void *_port)
{
diff --git a/drivers/tty/serial/lpc32xx_hs.c b/drivers/tty/serial/lpc32xx_hs.c
index ed47f4768338..b38fe4728c26 100644
--- a/drivers/tty/serial/lpc32xx_hs.c
+++ b/drivers/tty/serial/lpc32xx_hs.c
@@ -276,8 +276,6 @@ static void __serial_lpc32xx_rx(struct uart_port *port)
tty_flip_buffer_push(tport);
}

-static void serial_lpc32xx_stop_tx(struct uart_port *port);
-
static bool serial_lpc32xx_tx_ready(struct uart_port *port)
{
u32 level = readl(LPC32XX_HSUART_LEVEL(port->membase));
@@ -287,34 +285,11 @@ static bool serial_lpc32xx_tx_ready(struct uart_port *port)

static void __serial_lpc32xx_tx(struct uart_port *port)
{
- struct circ_buf *xmit = &port->state->xmit;
-
- if (port->x_char) {
- writel((u32)port->x_char, LPC32XX_HSUART_FIFO(port->membase));
- port->icount.tx++;
- port->x_char = 0;
- return;
- }
-
- if (uart_circ_empty(xmit) || uart_tx_stopped(port))
- goto exit_tx;
-
- /* Transfer data */
- while (serial_lpc32xx_tx_ready(port)) {
- writel((u32) xmit->buf[xmit->tail],
- LPC32XX_HSUART_FIFO(port->membase));
- 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);
+ u8 ch;

-exit_tx:
- if (uart_circ_empty(xmit))
- serial_lpc32xx_stop_tx(port);
+ uart_port_tx(port, ch,
+ serial_lpc32xx_tx_ready(port),
+ writel(ch, LPC32XX_HSUART_FIFO(port->membase)));
}

static irqreturn_t serial_lpc32xx_interrupt(int irq, void *dev_id)
diff --git a/drivers/tty/serial/mcf.c b/drivers/tty/serial/mcf.c
index b1cd9a76dd93..53b642ea46ba 100644
--- a/drivers/tty/serial/mcf.c
+++ b/drivers/tty/serial/mcf.c
@@ -327,29 +327,13 @@ static void mcf_rx_chars(struct mcf_uart *pp)
static void mcf_tx_chars(struct mcf_uart *pp)
{
struct uart_port *port = &pp->port;
- struct circ_buf *xmit = &port->state->xmit;
-
- if (port->x_char) {
- /* Send special char - probably flow control */
- writeb(port->x_char, port->membase + MCFUART_UTB);
- port->x_char = 0;
- port->icount.tx++;
- return;
- }
-
- while (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY) {
- if (uart_circ_empty(xmit))
- break;
- writeb(xmit->buf[xmit->tail], port->membase + MCFUART_UTB);
- xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE -1);
- port->icount.tx++;
- }
-
- if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
- uart_write_wakeup(port);
+ unsigned int pending;
+ u8 ch;

- if (uart_circ_empty(xmit)) {
- mcf_stop_tx(port);
+ pending = uart_port_tx(port, ch,
+ readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY,
+ writeb(ch, port->membase + MCFUART_UTB));
+ if (!pending) {
/* Disable TX to negate RTS automatically */
if (port->rs485.flags & SER_RS485_ENABLED)
writeb(MCFUART_UCR_TXDISABLE,
diff --git a/drivers/tty/serial/mpc52xx_uart.c b/drivers/tty/serial/mpc52xx_uart.c
index 73362d4bc45d..384ca195e3d5 100644
--- a/drivers/tty/serial/mpc52xx_uart.c
+++ b/drivers/tty/serial/mpc52xx_uart.c
@@ -1428,42 +1428,11 @@ mpc52xx_uart_int_rx_chars(struct uart_port *port)
static inline bool
mpc52xx_uart_int_tx_chars(struct uart_port *port)
{
- struct circ_buf *xmit = &port->state->xmit;
-
- /* Process out of band chars */
- if (port->x_char) {
- psc_ops->write_char(port, port->x_char);
- port->icount.tx++;
- port->x_char = 0;
- return true;
- }
-
- /* Nothing to do ? */
- if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
- mpc52xx_uart_stop_tx(port);
- return false;
- }
-
- /* Send chars */
- while (psc_ops->raw_tx_rdy(port)) {
- psc_ops->write_char(port, xmit->buf[xmit->tail]);
- xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
- port->icount.tx++;
- if (uart_circ_empty(xmit))
- break;
- }
-
- /* Wake up */
- if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
- uart_write_wakeup(port);
-
- /* Maybe we're done after all */
- if (uart_circ_empty(xmit)) {
- mpc52xx_uart_stop_tx(port);
- return false;
- }
+ u8 ch;

- return true;
+ return uart_port_tx(port, ch,
+ psc_ops->raw_tx_rdy(port),
+ psc_ops->write_char(port, ch));
}

static irqreturn_t
diff --git a/drivers/tty/serial/mps2-uart.c b/drivers/tty/serial/mps2-uart.c
index 2e3e6cf16817..860d161fa594 100644
--- a/drivers/tty/serial/mps2-uart.c
+++ b/drivers/tty/serial/mps2-uart.c
@@ -129,29 +129,11 @@ static void mps2_uart_stop_tx(struct uart_port *port)

static void mps2_uart_tx_chars(struct uart_port *port)
{
- struct circ_buf *xmit = &port->state->xmit;
-
- while (!(mps2_uart_read8(port, UARTn_STATE) & UARTn_STATE_TX_FULL)) {
- if (port->x_char) {
- mps2_uart_write8(port, port->x_char, UARTn_DATA);
- port->x_char = 0;
- port->icount.tx++;
- continue;
- }
-
- if (uart_circ_empty(xmit) || uart_tx_stopped(port))
- break;
-
- mps2_uart_write8(port, xmit->buf[xmit->tail], UARTn_DATA);
- xmit->tail = (xmit->tail + 1) % UART_XMIT_SIZE;
- port->icount.tx++;
- }
-
- if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
- uart_write_wakeup(port);
+ u8 ch;

- if (uart_circ_empty(xmit))
- mps2_uart_stop_tx(port);
+ uart_port_tx(port, ch,
+ mps2_uart_tx_empty(port),
+ mps2_uart_write8(port, ch, UARTn_DATA));
}

static void mps2_uart_start_tx(struct uart_port *port)
diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c
index d21a4f3ef2fe..ef6e7bb6105c 100644
--- a/drivers/tty/serial/mxs-auart.c
+++ b/drivers/tty/serial/mxs-auart.c
@@ -569,6 +569,8 @@ static int mxs_auart_dma_tx(struct mxs_auart_port *s, int size)
static void mxs_auart_tx_chars(struct mxs_auart_port *s)
{
struct circ_buf *xmit = &s->port.state->xmit;
+ bool pending;
+ u8 ch;

if (auart_dma_enabled(s)) {
u32 i = 0;
@@ -603,31 +605,13 @@ static void mxs_auart_tx_chars(struct mxs_auart_port *s)
return;
}

-
- while (!(mxs_read(s, REG_STAT) & AUART_STAT_TXFF)) {
- if (s->port.x_char) {
- s->port.icount.tx++;
- mxs_write(s->port.x_char, s, REG_DATA);
- s->port.x_char = 0;
- continue;
- }
- if (!uart_circ_empty(xmit) && !uart_tx_stopped(&s->port)) {
- s->port.icount.tx++;
- mxs_write(xmit->buf[xmit->tail], s, REG_DATA);
- xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
- } else
- break;
- }
- if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
- uart_write_wakeup(&s->port);
-
- if (uart_circ_empty(&(s->port.state->xmit)))
- mxs_clr(AUART_INTR_TXIEN, s, REG_INTR);
- else
+ pending = uart_port_tx(&s->port, ch,
+ !(mxs_read(s, REG_STAT) & AUART_STAT_TXFF),
+ mxs_write(ch, s, REG_DATA));
+ if (pending)
mxs_set(AUART_INTR_TXIEN, s, REG_INTR);
-
- if (uart_tx_stopped(&s->port))
- mxs_auart_stop_tx(&s->port);
+ else
+ mxs_clr(AUART_INTR_TXIEN, s, REG_INTR);
}

static void mxs_auart_rx_char(struct mxs_auart_port *s)
diff --git a/drivers/tty/serial/owl-uart.c b/drivers/tty/serial/owl-uart.c
index fde39cc1145d..e99970a9437f 100644
--- a/drivers/tty/serial/owl-uart.c
+++ b/drivers/tty/serial/owl-uart.c
@@ -181,35 +181,11 @@ static void owl_uart_start_tx(struct uart_port *port)

static void owl_uart_send_chars(struct uart_port *port)
{
- struct circ_buf *xmit = &port->state->xmit;
- unsigned int ch;
-
- if (port->x_char) {
- while (!(owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_TFFU))
- cpu_relax();
- owl_uart_write(port, port->x_char, OWL_UART_TXDAT);
- port->icount.tx++;
- port->x_char = 0;
- }
-
- if (uart_tx_stopped(port))
- return;
-
- while (!(owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_TFFU)) {
- if (uart_circ_empty(xmit))
- break;
+ u8 ch;

- ch = xmit->buf[xmit->tail];
- owl_uart_write(port, ch, OWL_UART_TXDAT);
- xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
- port->icount.tx++;
- }
-
- if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
- uart_write_wakeup(port);
-
- if (uart_circ_empty(xmit))
- owl_uart_stop_tx(port);
+ uart_port_tx(port, ch,
+ !(owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_TFFU),
+ owl_uart_write(port, ch, OWL_UART_TXDAT));
}

static void owl_uart_receive_chars(struct uart_port *port)
diff --git a/drivers/tty/serial/sa1100.c b/drivers/tty/serial/sa1100.c
index dd9e3253cab4..55107bbc00ce 100644
--- a/drivers/tty/serial/sa1100.c
+++ b/drivers/tty/serial/sa1100.c
@@ -228,14 +228,7 @@ sa1100_rx_chars(struct sa1100_port *sport)

static void sa1100_tx_chars(struct sa1100_port *sport)
{
- struct circ_buf *xmit = &sport->port.state->xmit;
-
- if (sport->port.x_char) {
- UART_PUT_CHAR(sport, sport->port.x_char);
- sport->port.icount.tx++;
- sport->port.x_char = 0;
- return;
- }
+ u8 ch;

/*
* Check the modem control lines before
@@ -243,28 +236,9 @@ static void sa1100_tx_chars(struct sa1100_port *sport)
*/
sa1100_mctrl_check(sport);

- if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
- sa1100_stop_tx(&sport->port);
- return;
- }
-
- /*
- * Tried using FIFO (not checking TNF) for fifo fill:
- * still had the '4 bytes repeated' problem.
- */
- while (UART_GET_UTSR1(sport) & UTSR1_TNF) {
- UART_PUT_CHAR(sport, xmit->buf[xmit->tail]);
- xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
- sport->port.icount.tx++;
- if (uart_circ_empty(xmit))
- break;
- }
-
- if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
- uart_write_wakeup(&sport->port);
-
- if (uart_circ_empty(xmit))
- sa1100_stop_tx(&sport->port);
+ uart_port_tx(&sport->port, ch,
+ UART_GET_UTSR1(sport) & UTSR1_TNF,
+ UART_PUT_CHAR(sport, ch));
}

static irqreturn_t sa1100_int(int irq, void *dev_id)
diff --git a/drivers/tty/serial/vt8500_serial.c b/drivers/tty/serial/vt8500_serial.c
index 10fbdb09965f..deedb6513160 100644
--- a/drivers/tty/serial/vt8500_serial.c
+++ b/drivers/tty/serial/vt8500_serial.c
@@ -196,33 +196,11 @@ static unsigned int vt8500_tx_empty(struct uart_port *port)

static void handle_tx(struct uart_port *port)
{
- struct circ_buf *xmit = &port->state->xmit;
+ u8 ch;

- if (port->x_char) {
- writeb(port->x_char, port->membase + VT8500_TXFIFO);
- port->icount.tx++;
- port->x_char = 0;
- }
- if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
- vt8500_stop_tx(port);
- return;
- }
-
- while (vt8500_tx_empty(port)) {
- if (uart_circ_empty(xmit))
- break;
-
- writeb(xmit->buf[xmit->tail], port->membase + VT8500_TXFIFO);
-
- xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
- port->icount.tx++;
- }
-
- if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
- uart_write_wakeup(port);
-
- if (uart_circ_empty(xmit))
- vt8500_stop_tx(port);
+ uart_port_tx(port, ch,
+ vt8500_tx_empty(port),
+ writeb(ch, port->membase + VT8500_TXFIFO));
}

static void vt8500_start_tx(struct uart_port *port)
--
2.37.3