serial: clps711x: Enable driver compilation with COMPILE_TEST

This helps increasing build testing coverage.
To do this, read{write}_relaxed() functions was be replaced with
simple read{write}() variants. Potential "uninitialized variable"
warnings was be fixed if driver compiled without MFD_SYSCON.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 23 insertions, 20 deletions

diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 7fbbbadea2dd..441ada489874 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -181,9 +181,8 @@ config SERIAL_KS8695_CONSOLE
 
 config SERIAL_CLPS711X
         tristate "CLPS711X serial port support"
-        depends on ARCH_CLPS711X
+        depends on ARCH_CLPS711X || COMPILE_TEST
         select SERIAL_CORE
-        default y
         help
           This enables the driver for the on-chip UARTs of the Cirrus
           Logic EP711x/EP721x/EP731x processors.
diff --git a/drivers/tty/serial/clps711x.c b/drivers/tty/serial/clps711x.c
index 5a931f97aa7c..b0eacb83f831 100644
--- a/drivers/tty/serial/clps711x.c
+++ b/drivers/tty/serial/clps711x.c
@@ -99,15 +99,16 @@ static irqreturn_t uart_clps711x_int_rx(int irq, void *dev_id)
         struct uart_port *port = dev_id;
         struct clps711x_port *s = dev_get_drvdata(port->dev);
         unsigned int status, flg;
-        u32 sysflg;
         u16 ch;
 
         for (;;) {
+                u32 sysflg = 0;
+
                 regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
                 if (sysflg & SYSFLG_URXFE)
                         break;
 
-                ch = readw_relaxed(port->membase + UARTDR_OFFSET);
+                ch = readw(port->membase + UARTDR_OFFSET);
                 status = ch & (UARTDR_FRMERR | UARTDR_PARERR | UARTDR_OVERR);
                 ch &= 0xff;
 
@@ -151,10 +152,9 @@ static irqreturn_t uart_clps711x_int_tx(int irq, void *dev_id)
         struct uart_port *port = dev_id;
         struct clps711x_port *s = dev_get_drvdata(port->dev);
         struct circ_buf *xmit = &port->state->xmit;
-        u32 sysflg;
 
         if (port->x_char) {
-                writew_relaxed(port->x_char, port->membase + UARTDR_OFFSET);
+                writew(port->x_char, port->membase + UARTDR_OFFSET);
                 port->icount.tx++;
                 port->x_char = 0;
                 return IRQ_HANDLED;
@@ -169,8 +169,9 @@ static irqreturn_t uart_clps711x_int_tx(int irq, void *dev_id)
         }
 
         while (!uart_circ_empty(xmit)) {
-                writew_relaxed(xmit->buf[xmit->tail],
-                               port->membase + UARTDR_OFFSET);
+                u32 sysflg = 0;
+
+                writew(xmit->buf[xmit->tail], port->membase + UARTDR_OFFSET);
                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
                 port->icount.tx++;
 
@@ -188,7 +189,7 @@ static irqreturn_t uart_clps711x_int_tx(int irq, void *dev_id)
 static unsigned int uart_clps711x_tx_empty(struct uart_port *port)
 {
         struct clps711x_port *s = dev_get_drvdata(port->dev);
-        u32 sysflg;
+        u32 sysflg = 0;
 
         regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
 
@@ -199,9 +200,10 @@ static unsigned int uart_clps711x_get_mctrl(struct uart_port *port)
 {
         struct clps711x_port *s = dev_get_drvdata(port->dev);
         unsigned int result = 0;
-        u32 sysflg;
 
         if (s->use_ms) {
+                u32 sysflg = 0;
+
                 regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
                 if (sysflg & SYSFLG1_DCD)
                         result |= TIOCM_CAR;
@@ -224,12 +226,12 @@ static void uart_clps711x_break_ctl(struct uart_port *port, int break_state)
 {
         unsigned int ubrlcr;
 
-        ubrlcr = readl_relaxed(port->membase + UBRLCR_OFFSET);
+        ubrlcr = readl(port->membase + UBRLCR_OFFSET);
         if (break_state)
                 ubrlcr |= UBRLCR_BREAK;
         else
                 ubrlcr &= ~UBRLCR_BREAK;
-        writel_relaxed(ubrlcr, port->membase + UBRLCR_OFFSET);
+        writel(ubrlcr, port->membase + UBRLCR_OFFSET);
 }
 
 static void uart_clps711x_set_ldisc(struct uart_port *port, int ld)
@@ -247,8 +249,8 @@ static int uart_clps711x_startup(struct uart_port *port)
         struct clps711x_port *s = dev_get_drvdata(port->dev);
 
         /* Disable break */
-        writel_relaxed(readl_relaxed(port->membase + UBRLCR_OFFSET) &
-                       ~UBRLCR_BREAK, port->membase + UBRLCR_OFFSET);
+        writel(readl(port->membase + UBRLCR_OFFSET) & ~UBRLCR_BREAK,
+               port->membase + UBRLCR_OFFSET);
 
         /* Enable the port */
         return regmap_update_bits(s->syscon, SYSCON_OFFSET,
@@ -320,7 +322,7 @@ static void uart_clps711x_set_termios(struct uart_port *port,
 
         uart_update_timeout(port, termios->c_cflag, baud);
 
-        writel_relaxed(ubrlcr | (quot - 1), port->membase + UBRLCR_OFFSET);
+        writel(ubrlcr | (quot - 1), port->membase + UBRLCR_OFFSET);
 }
 
 static const char *uart_clps711x_type(struct uart_port *port)
@@ -366,13 +368,13 @@ static const struct uart_ops uart_clps711x_ops = {
 static void uart_clps711x_console_putchar(struct uart_port *port, int ch)
 {
         struct clps711x_port *s = dev_get_drvdata(port->dev);
-        u32 sysflg;
+        u32 sysflg = 0;
 
         do {
                 regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
         } while (sysflg & SYSFLG_UTXFF);
 
-        writew_relaxed(ch, port->membase + UARTDR_OFFSET);
+        writew(ch, port->membase + UARTDR_OFFSET);
 }
 
 static void uart_clps711x_console_write(struct console *co, const char *c,
@@ -380,7 +382,7 @@ static void uart_clps711x_console_write(struct console *co, const char *c,
 {
         struct uart_port *port = clps711x_uart.state[co->index].uart_port;
         struct clps711x_port *s = dev_get_drvdata(port->dev);
-        u32 sysflg;
+        u32 sysflg = 0;
 
         uart_console_write(port, c, n, uart_clps711x_console_putchar);
 
@@ -396,8 +398,8 @@ static int uart_clps711x_console_setup(struct console *co, char *options)
         int ret, index = co->index;
         struct clps711x_port *s;
         struct uart_port *port;
-        u32 ubrlcr, syscon;
         unsigned int quot;
+        u32 ubrlcr;
 
         if (index < 0 || index >= UART_CLPS711X_NR)
                 return -EINVAL;
@@ -409,9 +411,11 @@ static int uart_clps711x_console_setup(struct console *co, char *options)
         s = dev_get_drvdata(port->dev);
 
         if (!options) {
+                u32 syscon = 0;
+
                 regmap_read(s->syscon, SYSCON_OFFSET, &syscon);
                 if (syscon & SYSCON_UARTEN) {
-                        ubrlcr = readl_relaxed(port->membase + UBRLCR_OFFSET);
+                        ubrlcr = readl(port->membase + UBRLCR_OFFSET);
 
                         if (ubrlcr & UBRLCR_PRTEN) {
                                 if (ubrlcr & UBRLCR_EVENPRT)