altera_uart: Add support for different address strides

Some controllers implement registers with a stride, to support
those we must implement the proper IO accessors.
Signed-off-by: NAnton Vorontsov <cbouatmailru@gmail.com>
Acked-by: NTobias Klauser <tklauser@distanz.ch>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/serial/altera_uart.c

@@ -82,9 +82,23 @@ struct altera_uart {
 	unsigned short imr;	/* Local IMR mirror */
 };
 
+static u32 altera_uart_readl(struct uart_port *port, int reg)
+{
+	struct altera_uart_platform_uart *platp = port->private_data;
+
+	return readl(port->membase + (reg << platp->bus_shift));
+}
+
+static void altera_uart_writel(struct uart_port *port, u32 dat, int reg)
+{
+	struct altera_uart_platform_uart *platp = port->private_data;
+
+	writel(dat, port->membase + (reg << platp->bus_shift));
+}
+
 static unsigned int altera_uart_tx_empty(struct uart_port *port)
 {
-	return (readl(port->membase + ALTERA_UART_STATUS_REG) &
+	return (altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
 		ALTERA_UART_STATUS_TMT_MSK) ? TIOCSER_TEMT : 0;
 }
 
@@ -93,8 +107,7 @@ static unsigned int altera_uart_get_mctrl(struct uart_port *port)
 	struct altera_uart *pp = container_of(port, struct altera_uart, port);
 	unsigned int sigs;
 
-	sigs =
-	    (readl(port->membase + ALTERA_UART_STATUS_REG) &
+	sigs = (altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
 	     ALTERA_UART_STATUS_CTS_MSK) ? TIOCM_CTS : 0;
 	sigs |= (pp->sigs & TIOCM_RTS);
 
@@ -110,7 +123,7 @@ static void altera_uart_set_mctrl(struct uart_port *port, unsigned int sigs)
 		pp->imr |= ALTERA_UART_CONTROL_RTS_MSK;
 	else
 		pp->imr &= ~ALTERA_UART_CONTROL_RTS_MSK;
-	writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
+	altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
 }
 
 static void altera_uart_start_tx(struct uart_port *port)
@@ -118,7 +131,7 @@ static void altera_uart_start_tx(struct uart_port *port)
 	struct altera_uart *pp = container_of(port, struct altera_uart, port);
 
 	pp->imr |= ALTERA_UART_CONTROL_TRDY_MSK;
-	writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
+	altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
 }
 
 static void altera_uart_stop_tx(struct uart_port *port)
@@ -126,7 +139,7 @@ static void altera_uart_stop_tx(struct uart_port *port)
 	struct altera_uart *pp = container_of(port, struct altera_uart, port);
 
 	pp->imr &= ~ALTERA_UART_CONTROL_TRDY_MSK;
-	writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
+	altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
 }
 
 static void altera_uart_stop_rx(struct uart_port *port)
@@ -134,7 +147,7 @@ static void altera_uart_stop_rx(struct uart_port *port)
 	struct altera_uart *pp = container_of(port, struct altera_uart, port);
 
 	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);
 }
 
 static void altera_uart_break_ctl(struct uart_port *port, int break_state)
@@ -147,7 +160,7 @@ static void altera_uart_break_ctl(struct uart_port *port, int break_state)
 		pp->imr |= ALTERA_UART_CONTROL_TRBK_MSK;
 	else
 		pp->imr &= ~ALTERA_UART_CONTROL_TRBK_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);
 }
 
@@ -171,7 +184,7 @@ static void altera_uart_set_termios(struct uart_port *port,
 
 	spin_lock_irqsave(&port->lock, flags);
 	uart_update_timeout(port, termios->c_cflag, baud);
-	writel(baudclk, port->membase + ALTERA_UART_DIVISOR_REG);
+	altera_uart_writel(port, baudclk, ALTERA_UART_DIVISOR_REG);
 	spin_unlock_irqrestore(&port->lock, flags);
 }
 
@@ -181,14 +194,15 @@ static void altera_uart_rx_chars(struct altera_uart *pp)
 	unsigned char ch, flag;
 	unsigned short status;
 
-	while ((status = readl(port->membase + ALTERA_UART_STATUS_REG)) &
+	while ((status = altera_uart_readl(port, ALTERA_UART_STATUS_REG)) &
 	       ALTERA_UART_STATUS_RRDY_MSK) {
-		ch = readl(port->membase + ALTERA_UART_RXDATA_REG);
+		ch = altera_uart_readl(port, ALTERA_UART_RXDATA_REG);
 		flag = TTY_NORMAL;
 		port->icount.rx++;
 
 		if (status & ALTERA_UART_STATUS_E_MSK) {
-			writel(status, port->membase + ALTERA_UART_STATUS_REG);
+			altera_uart_writel(port, status,
+					   ALTERA_UART_STATUS_REG);
 
 			if (status & ALTERA_UART_STATUS_BRK_MSK) {
 				port->icount.brk++;
@@ -228,18 +242,18 @@ static void altera_uart_tx_chars(struct altera_uart *pp)
 
 	if (port->x_char) {
 		/* Send special char - probably flow control */
-		writel(port->x_char, port->membase + ALTERA_UART_TXDATA_REG);
+		altera_uart_writel(port, port->x_char, ALTERA_UART_TXDATA_REG);
 		port->x_char = 0;
 		port->icount.tx++;
 		return;
 	}
 
-	while (readl(port->membase + ALTERA_UART_STATUS_REG) &
+	while (altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
 	       ALTERA_UART_STATUS_TRDY_MSK) {
 		if (xmit->head == xmit->tail)
 			break;
-		writel(xmit->buf[xmit->tail],
-		       port->membase + ALTERA_UART_TXDATA_REG);
+		altera_uart_writel(port, xmit->buf[xmit->tail],
+		       ALTERA_UART_TXDATA_REG);
 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 		port->icount.tx++;
 	}
@@ -249,7 +263,7 @@ static void altera_uart_tx_chars(struct altera_uart *pp)
 
 	if (xmit->head == xmit->tail) {
 		pp->imr &= ~ALTERA_UART_CONTROL_TRDY_MSK;
-		writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
+		altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
 	}
 }
 
@@ -259,7 +273,7 @@ static irqreturn_t altera_uart_interrupt(int irq, void *data)
 	struct altera_uart *pp = container_of(port, struct altera_uart, port);
 	unsigned int isr;
 
-	isr = readl(port->membase + ALTERA_UART_STATUS_REG) & pp->imr;
+	isr = altera_uart_readl(port, ALTERA_UART_STATUS_REG) & pp->imr;
 
 	spin_lock(&port->lock);
 	if (isr & ALTERA_UART_STATUS_RRDY_MSK)
@@ -285,9 +299,9 @@ static void altera_uart_config_port(struct uart_port *port, int flags)
 	port->type = PORT_ALTERA_UART;
 
 	/* Clear mask, so no surprise interrupts. */
-	writel(0, port->membase + ALTERA_UART_CONTROL_REG);
+	altera_uart_writel(port, 0, ALTERA_UART_CONTROL_REG);
 	/* Clear status register */
-	writel(0, port->membase + ALTERA_UART_STATUS_REG);
+	altera_uart_writel(port, 0, ALTERA_UART_STATUS_REG);
 }
 
 static int altera_uart_startup(struct uart_port *port)
@@ -407,6 +421,7 @@ int __init early_altera_uart_setup(struct altera_uart_platform_uart *platp)
 		port->uartclk = platp[i].uartclk;
 		port->flags = ASYNC_BOOT_AUTOCONF;
 		port->ops = &altera_uart_ops;
+		port->private_data = platp;
 	}
 
 	return 0;
@@ -414,7 +429,7 @@ int __init early_altera_uart_setup(struct altera_uart_platform_uart *platp)
 
 static void altera_uart_console_putc(struct uart_port *port, const char c)
 {
-	while (!(readl(port->membase + ALTERA_UART_STATUS_REG) &
+	while (!(altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
 		 ALTERA_UART_STATUS_TRDY_MSK))
 		cpu_relax();
 
@@ -535,6 +550,7 @@ static int __devinit altera_uart_probe(struct platform_device *pdev)
 	port->uartclk = platp->uartclk;
 	port->ops = &altera_uart_ops;
 	port->flags = ASYNC_BOOT_AUTOCONF;
+	port->private_data = platp;
 
 	uart_add_one_port(&altera_uart_driver, port);
 

include/linux/altera_uart.h

@@ -9,6 +9,7 @@ struct altera_uart_platform_uart {
 	unsigned long mapbase;	/* Physical address base */
 	unsigned int irq;	/* Interrupt vector */
 	unsigned int uartclk;	/* UART clock rate */
+	unsigned int bus_shift;	/* Bus shift (address stride) */
 };
 
 #endif /* __ALTUART_H */