atmel_serial: keep clock off when it's not needed

[linux-2.6-omap-h63xx.git] / drivers / serial / atmel_serial.c

diff --git a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c
index 61fb8b6d19af77be5a9b180532725c22df68d44d..d5efd6c77904aef0dbb74641820b8937890f4ae5 100644 (file)
--- a/drivers/serial/atmel_serial.c
+++ b/drivers/serial/atmel_serial.c
@@ -1258,6 +1258,8 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
                atmel_port->clk = clk_get(&pdev->dev, "usart");
                clk_enable(atmel_port->clk);
                port->uartclk = clk_get_rate(atmel_port->clk);
+               clk_disable(atmel_port->clk);
+               /* only enable clock when USART is in use */
        }
 
        atmel_port->use_dma_rx = data->use_dma_rx;
@@ -1379,6 +1381,8 @@ static int __init atmel_console_setup(struct console *co, char *options)
                return -ENODEV;
        }
 
+       clk_enable(atmel_ports[co->index].clk);
+
        UART_PUT_IDR(port, -1);
        UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
        UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
@@ -1403,7 +1407,7 @@ static struct console atmel_console = {
        .data           = &atmel_uart,
 };
 
-#define ATMEL_CONSOLE_DEVICE   &atmel_console
+#define ATMEL_CONSOLE_DEVICE   (&atmel_console)
 
 /*
  * Early console initialization (before VM subsystem initialized).
@@ -1534,6 +1538,15 @@ static int __devinit atmel_serial_probe(struct platform_device *pdev)
        if (ret)
                goto err_add_port;
 
+       if (atmel_is_console_port(&port->uart)
+                       && ATMEL_CONSOLE_DEVICE->flags & CON_ENABLED) {
+               /*
+                * The serial core enabled the clock for us, so undo
+                * the clk_enable() in atmel_console_setup()
+                */
+               clk_disable(port->clk);
+       }
+
        device_init_wakeup(&pdev->dev, 1);
        platform_set_drvdata(pdev, port);
 
@@ -1544,7 +1557,6 @@ err_add_port:
        port->rx_ring.buf = NULL;
 err_alloc_ring:
        if (!atmel_is_console_port(&port->uart)) {
-               clk_disable(port->clk);
                clk_put(port->clk);
                port->clk = NULL;
        }
@@ -1568,7 +1580,6 @@ static int __devexit atmel_serial_remove(struct platform_device *pdev)
 
        /* "port" is allocated statically, so we shouldn't free it */
 
-       clk_disable(atmel_port->clk);
        clk_put(atmel_port->clk);
 
        return ret;