linux-kernel - [PATCH 08/11] serial: fsl_linflexuart: deduplicate character sending

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Date:   Mon, 24 Jan 2022 08:14:27 +0100
From:   Jiri Slaby <jslaby@...e.cz>
To:     gregkh@...uxfoundation.org
Cc:     linux-serial@...r.kernel.org, linux-kernel@...r.kernel.org,
        johan@...nel.org, Jiri Slaby <jslaby@...e.cz>,
        Stefan-gabriel Mirea <stefan-gabriel.mirea@....com>
Subject: [PATCH 08/11] serial: fsl_linflexuart: deduplicate character sending

Introduce a new linflex_put_char() helper to send a character. And use
it on both places this code was duplicated.

Signed-off-by: Jiri Slaby <jslaby@...e.cz>
Cc: Stefan-gabriel Mirea <stefan-gabriel.mirea@....com>
---
 drivers/tty/serial/fsl_linflexuart.c | 42 +++++++++++-----------------
 1 file changed, 17 insertions(+), 25 deletions(-)

diff --git a/drivers/tty/serial/fsl_linflexuart.c b/drivers/tty/serial/fsl_linflexuart.c
index 283757264608..81a04039b6c1 100644
--- a/drivers/tty/serial/fsl_linflexuart.c
+++ b/drivers/tty/serial/fsl_linflexuart.c
@@ -157,27 +157,29 @@ static void linflex_stop_rx(struct uart_port *port)
 	writel(ier & ~LINFLEXD_LINIER_DRIE, port->membase + LINIER);
 }
 
-static inline void linflex_transmit_buffer(struct uart_port *sport)
+static void linflex_put_char(struct uart_port *sport, unsigned char c)
 {
-	struct circ_buf *xmit = &sport->state->xmit;
-	unsigned char c;
 	unsigned long status;
 
-	while (!uart_circ_empty(xmit)) {
-		c = xmit->buf[xmit->tail];
-		writeb(c, sport->membase + BDRL);
+	writeb(c, sport->membase + BDRL);
 
-		/* Waiting for data transmission completed. */
-		while (((status = readl(sport->membase + UARTSR)) &
-					LINFLEXD_UARTSR_DTFTFF) !=
-					LINFLEXD_UARTSR_DTFTFF)
-			;
+	/* Waiting for data transmission completed. */
+	while (((status = readl(sport->membase + UARTSR)) &
+				LINFLEXD_UARTSR_DTFTFF) !=
+				LINFLEXD_UARTSR_DTFTFF)
+		;
+
+	writel(status | LINFLEXD_UARTSR_DTFTFF, sport->membase + UARTSR);
+}
 
+static inline void linflex_transmit_buffer(struct uart_port *sport)
+{
+	struct circ_buf *xmit = &sport->state->xmit;
+
+	while (!uart_circ_empty(xmit)) {
+		linflex_put_char(sport, xmit->buf[xmit->tail]);
 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 		sport->icount.tx++;
-
-		writel(status | LINFLEXD_UARTSR_DTFTFF,
-		       sport->membase + UARTSR);
 	}
 
 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
@@ -201,21 +203,11 @@ static irqreturn_t linflex_txint(int irq, void *dev_id)
 	struct uart_port *sport = dev_id;
 	struct circ_buf *xmit = &sport->state->xmit;
 	unsigned long flags;
-	unsigned long status;
 
 	spin_lock_irqsave(&sport->lock, flags);
 
 	if (sport->x_char) {
-		writeb(sport->x_char, sport->membase + BDRL);
-
-		/* waiting for data transmission completed */
-		while (((status = readl(sport->membase + UARTSR)) &
-			LINFLEXD_UARTSR_DTFTFF) != LINFLEXD_UARTSR_DTFTFF)
-			;
-
-		writel(status | LINFLEXD_UARTSR_DTFTFF,
-		       sport->membase + UARTSR);
-
+		linflex_put_char(sport, sport->x_char);
 		goto out;
 	}
 
-- 
2.34.1