tty: serial: altera_uart: Use port->regshift to store bus shift

Use the regshift member of struct uart_port to store the address stride
from platform data. This way we can save one dereference per call of
altera_uart_readl and altera_uart_writel.

This also allows us to use the driver without platform data, which is
needed for device tree support in the Nios2 port.

Acked-by: Anton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/tty/serial/altera_uart.c b/drivers/tty/serial/altera_uart.c
index dee7a0e..3a57352 100644 (file)
--- a/drivers/tty/serial/altera_uart.c
+++ b/drivers/tty/serial/altera_uart.c
@@ -86,16 +86,12 @@ struct altera_uart {
 
 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));
+       return readl(port->membase + (reg << port->regshift));
 }
 
 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));
+       writel(dat, port->membase + (reg << port->regshift));
 }
 
 static unsigned int altera_uart_tx_empty(struct uart_port *port)
@@ -546,13 +542,17 @@ static int __devinit altera_uart_probe(struct platform_device *pdev)
        if (!port->membase)
                return -ENOMEM;
 
+       if (platp)
+               port->regshift = platp->bus_shift;
+       else
+               port->regshift = 0;
+
        port->line = i;
        port->type = PORT_ALTERA_UART;
        port->iotype = SERIAL_IO_MEM;
        port->uartclk = platp->uartclk;
        port->ops = &altera_uart_ops;
        port->flags = UPF_BOOT_AUTOCONF;
-       port->private_data = platp;
 
        uart_add_one_port(&altera_uart_driver, port);