serial: altera: ensure port->regshift is honored consistently

Most register accesses in the altera driver honor port->regshift by
using altera_uart_writel(). There are a few accesses however that were
missed when the driver was converted to use port->regshift and some
others were added later in commit 4d9d7d8 ("serial: altera_uart:
add earlycon support").

Fixes: 2780ad4 ("tty: serial: altera_uart: Use port->regshift to store bus shift")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/altera_uart.c

@@ -327,7 +327,7 @@ static int altera_uart_startup(struct uart_port *port)
 
 	/* Enable RX interrupts now */
 	pp->imr = ALTERA_UART_CONTROL_RRDY_MSK;
-	writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
+	altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
 
 	spin_unlock_irqrestore(&port->lock, flags);
 
@@ -343,7 +343,7 @@ static void altera_uart_shutdown(struct uart_port *port)
 
 	/* Disable all interrupts now */
 	pp->imr = 0;
-	writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
+	altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
 
 	spin_unlock_irqrestore(&port->lock, flags);
 
@@ -432,7 +432,7 @@ static void altera_uart_console_putc(struct uart_port *port, int c)
 		 ALTERA_UART_STATUS_TRDY_MSK))
 		cpu_relax();
 
-	writel(c, port->membase + ALTERA_UART_TXDATA_REG);
+	altera_uart_writel(port, c, ALTERA_UART_TXDATA_REG);
 }
 
 static void altera_uart_console_write(struct console *co, const char *s,
@@ -502,13 +502,13 @@ static int __init altera_uart_earlycon_setup(struct earlycon_device *dev,
 		return -ENODEV;
 
 	/* Enable RX interrupts now */
-	writel(ALTERA_UART_CONTROL_RRDY_MSK,
-	       port->membase + ALTERA_UART_CONTROL_REG);
+	altera_uart_writel(port, ALTERA_UART_CONTROL_RRDY_MSK,
+			   ALTERA_UART_CONTROL_REG);
 
 	if (dev->baud) {
 		unsigned int baudclk = port->uartclk / dev->baud;
 
-		writel(baudclk, port->membase + ALTERA_UART_DIVISOR_REG);
+		altera_uart_writel(port, baudclk, ALTERA_UART_DIVISOR_REG);
 	}
 
 	dev->con->write = altera_uart_earlycon_write;