From 28eb4274e7ec3ddba6711e3d13e374046b3c2230 Mon Sep 17 00:00:00 2001 From: Huang Shijie Date: Tue, 4 Jun 2013 09:59:33 +0800 Subject: [PATCH] serial: imx: enable the clocks only when the uart is used 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 Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/imx.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index 381a2d79593c..831324a9745b 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -700,6 +700,14 @@ static int imx_startup(struct uart_port *port) int retval; unsigned long flags, temp; + retval = clk_prepare_enable(sport->clk_per); + if (retval) + goto error_out1; + + retval = clk_prepare_enable(sport->clk_ipg); + if (retval) + goto error_out1; + imx_setup_ufcr(sport, 0); /* disable the DREN bit (Data Ready interrupt enable) before @@ -885,6 +893,9 @@ 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 @@ -1563,6 +1574,9 @@ 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) @@ -1584,9 +1598,6 @@ 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); -- 2.39.5