tty: serial: unify TX space reads under altera_jtaguart_tx_space()

TX space reads from the control register are performed in various forms
on 4 places in altera_jtaguart. Unify all those and do the read and
masking on a single place.

The new helper altera_jtaguart_tx_space() uses FIELD_GET(), so we can
drop ALTERA_JTAGUART_CONTROL_WSPACE_OFF now.

Cc: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Acked-by: Tobias Klauser <tklauser@distanz.ch>
Link: https://lore.kernel.org/r/20220927111819.18516-3-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/altera_jtaguart.c b/drivers/tty/serial/altera_jtaguart.c
index 23f339757894f1458c58d06d63c4ea4ef4343bf3..ac8ce418de36d606e7a9cb57a9ed5031607369e5 100644 (file)
--- a/drivers/tty/serial/altera_jtaguart.c
+++ b/drivers/tty/serial/altera_jtaguart.c
@@ -9,6 +9,7 @@
  * (C) Copyright 2010, Tobias Klauser <tklauser@distanz.ch>
  */
 
+#include <linux/bitfield.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
@@ -48,7 +49,6 @@
 #define ALTERA_JTAGUART_CONTROL_WI_MSK         0x00000200
 #define ALTERA_JTAGUART_CONTROL_AC_MSK         0x00000400
 #define ALTERA_JTAGUART_CONTROL_WSPACE_MSK     0xFFFF0000
-#define ALTERA_JTAGUART_CONTROL_WSPACE_OFF     16
 
 /*
  * Local per-uart structure.
@@ -59,10 +59,19 @@ struct altera_jtaguart {
        unsigned long imr;      /* Local IMR mirror */
 };
 
+static unsigned int altera_jtaguart_tx_space(struct uart_port *port, u32 *ctlp)
+{
+       u32 ctl = readl(port->membase + ALTERA_JTAGUART_CONTROL_REG);
+
+       if (ctlp)
+               *ctlp = ctl;
+
+       return FIELD_GET(ALTERA_JTAGUART_CONTROL_WSPACE_MSK, ctl);
+}
+
 static unsigned int altera_jtaguart_tx_empty(struct uart_port *port)
 {
-       return (readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) &
-               ALTERA_JTAGUART_CONTROL_WSPACE_MSK) ? TIOCSER_TEMT : 0;
+       return altera_jtaguart_tx_space(port, NULL) ? TIOCSER_TEMT : 0;
 }
 
 static unsigned int altera_jtaguart_get_mctrl(struct uart_port *port)
@@ -150,9 +159,7 @@ static void altera_jtaguart_tx_chars(struct altera_jtaguart *pp)
 
        pending = uart_circ_chars_pending(xmit);
        if (pending > 0) {
-               count = (readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) &
-                               ALTERA_JTAGUART_CONTROL_WSPACE_MSK) >>
-                       ALTERA_JTAGUART_CONTROL_WSPACE_OFF;
+               count = altera_jtaguart_tx_space(port, NULL);
                if (count > pending)
                        count = pending;
                if (count > 0) {
@@ -298,12 +305,11 @@ static struct altera_jtaguart altera_jtaguart_ports[ALTERA_JTAGUART_MAXPORTS];
 #if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE_BYPASS)
 static void altera_jtaguart_console_putc(struct uart_port *port, unsigned char c)
 {
-       unsigned long status;
        unsigned long flags;
+       u32 status;
 
        spin_lock_irqsave(&port->lock, flags);
-       while (((status = readl(port->membase + ALTERA_JTAGUART_CONTROL_REG)) &
-               ALTERA_JTAGUART_CONTROL_WSPACE_MSK) == 0) {
+       while (!altera_jtaguart_tx_space(port, &status)) {
                if ((status & ALTERA_JTAGUART_CONTROL_AC_MSK) == 0) {
                        spin_unlock_irqrestore(&port->lock, flags);
                        return; /* no connection activity */
@@ -321,8 +327,7 @@ static void altera_jtaguart_console_putc(struct uart_port *port, unsigned char c
        unsigned long flags;
 
        spin_lock_irqsave(&port->lock, flags);
-       while ((readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) &
-               ALTERA_JTAGUART_CONTROL_WSPACE_MSK) == 0) {
+       while (!altera_jtaguart_tx_space(port, NULL)) {
                spin_unlock_irqrestore(&port->lock, flags);
                cpu_relax();
                spin_lock_irqsave(&port->lock, flags);