[PATCH] serial: imx: enable the clocks only when the uart is used

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Current code opens the clocks when the uart driver is probed.
This will wastes some power if several uarts are enabled, but not really
used.

So close these clocks for uart, and enable the clocks only when
the uart is used.

Signed-off-by: Huang Shijie <b32955@xxxxxxxxxxxxx>
---
 drivers/tty/serial/imx.c |   12 +++++++++---
 1 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 72bc1db..5705fc8 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -699,6 +699,9 @@ static int imx_startup(struct uart_port *port)
 	int retval;
 	unsigned long flags, temp;
 
+	clk_prepare_enable(sport->clk_per);
+	clk_prepare_enable(sport->clk_ipg);
+
 	imx_setup_ufcr(sport, 0);
 
 	/* disable the DREN bit (Data Ready interrupt enable) before
@@ -884,6 +887,9 @@ static void imx_shutdown(struct uart_port *port)
 
 	writel(temp, sport->port.membase + UCR1);
 	spin_unlock_irqrestore(&sport->port.lock, flags);
+
+	clk_disable_unprepare(sport->clk_per);
+	clk_disable_unprepare(sport->clk_ipg);
 }
 
 static void
@@ -1557,6 +1563,9 @@ static int serial_imx_probe(struct platform_device *pdev)
 		goto deinit;
 	platform_set_drvdata(pdev, sport);
 
+	clk_disable_unprepare(sport->clk_per);
+	clk_disable_unprepare(sport->clk_ipg);
+
 	return 0;
 deinit:
 	if (pdata && pdata->exit)
@@ -1578,9 +1587,6 @@ static int serial_imx_remove(struct platform_device *pdev)
 
 	uart_remove_one_port(&imx_reg, &sport->port);
 
-	clk_disable_unprepare(sport->clk_per);
-	clk_disable_unprepare(sport->clk_ipg);
-
 	if (pdata && pdata->exit)
 		pdata->exit(pdev);
 
-- 
1.7.1


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




[Index of Archives]     [Kernel Newbies]     [Security]     [Netfilter]     [Bugtraq]     [Linux PPP]     [Linux FS]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Video 4 Linux]     [Linmodem]     [Device Mapper]     [Linux Kernel for ARM]

  Powered by Linux