Re: [PATCH] serial/imx: enable the clock when we really use the uart port

[Huang Shijie <b32955@xxxxxxxxxxxxx>]

于 2012年05月02日 16:19, Sascha Hauer 写道:
> On Wed, May 02, 2012 at 04:19:30PM +0800, Huang Shijie wrote:
> > The current code keeps the clock enabled even when we do not really
> > use the uart port. But keep the clock enabled will consume some power.
> >
> > In order to save more power, disable the clock when we do not use
> > the uart, and enable the clock when we really use the uart port.
> >
> > Signed-off-by: Huang Shijie<b32955@xxxxxxxxxxxxx>
> This conflicts with my series converting i.MX to the common clock
> framework. Please lets delay this until this has been merged.
OK, thanks

Huang Shijie
> Sascha
>
> > ---
> >   drivers/tty/serial/imx.c |    6 +++++-
> >   1 files changed, 5 insertions(+), 1 deletions(-)
> >
> > diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
> > index e7fecee..f5dcdf6 100644
> > --- a/drivers/tty/serial/imx.c
> > +++ b/drivers/tty/serial/imx.c
> > @@ -694,6 +694,8 @@ static int imx_startup(struct uart_port *port)
> >   	int retval;
> >   	unsigned long flags, temp;
> >
> > +	clk_prepare_enable(sport->clk);
> > +
> >   	imx_setup_ufcr(sport, 0);
> >
> >   	/* disable the DREN bit (Data Ready interrupt enable) before
> > @@ -877,6 +879,8 @@ static void imx_shutdown(struct uart_port *port)
> >   		temp&= ~(UCR1_IREN);
> >
> >   	writel(temp, sport->port.membase + UCR1);
> > +
> > +	clk_disable_unprepare(sport->clk);
> >   }
> >
> >   static void
> > @@ -1526,6 +1530,7 @@ static int serial_imx_probe(struct platform_device *pdev)
> >   		goto deinit;
> >   	platform_set_drvdata(pdev,&sport->port);
> >
> > +	clk_disable_unprepare(sport->clk);
> >   	return 0;
> >   deinit:
> >   	if (pdata&&  pdata->exit)
> > @@ -1552,7 +1557,6 @@ static int serial_imx_remove(struct platform_device *pdev)
> >
> >   	if (sport) {
> >   		uart_remove_one_port(&imx_reg,&sport->port);
> > -		clk_disable_unprepare(sport->clk);
> >   		clk_put(sport->clk);
> >   	}
> >
> > --
> > 1.7.3.2



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