[PATCH 2/4] tty: serial: altera_uart: Use port->regshift to store bus shift

From: Tobias Klauser
Date: Wed Feb 09 2011 - 04:57:13 EST


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.

Cc: Anton Vorontsov <cbouatmailru@xxxxxxxxx>
Signed-off-by: Tobias Klauser <tklauser@xxxxxxxxxx>
---
drivers/tty/serial/altera_uart.c | 14 +++++++-------
1 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/tty/serial/altera_uart.c b/drivers/tty/serial/altera_uart.c
index dee7a0e..3a57352 100644
--- 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);

--
1.7.0.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/