Re: [PATCH 1/4] tty: serial: 8250_mtk: Use devm_clk_get

[Sascha Hauer <s.hauer@pengutronix.de>]

On Fri, Apr 24, 2015 at 12:53:08PM +0200, Matthias Brugger wrote:
> 2015-04-24 12:31 GMT+02:00 Sascha Hauer <s.hauer@pengutronix.de>:
> > On Fri, Apr 24, 2015 at 12:28:33PM +0200, Matthias Brugger wrote:
> >> 2015-04-23 10:51 GMT+02:00 Sascha Hauer <s.hauer@pengutronix.de>:
> >> > Just because of_clk_get() doesn't mean it should be used. Use devm_clk_get
> >> > which is the correct function when a struct device * is available. Also
> >> > since it's a devm function we can drop the calls to clk_put(). While at
> >> > it also fix a wrong debug message.
> >> >
> >> > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> >> > ---
> >> >  drivers/tty/serial/8250/8250_mtk.c | 7 ++-----
> >> >  1 file changed, 2 insertions(+), 5 deletions(-)
> >> >
> >> > diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
> >> > index 7a11fac..c6901dc 100644
> >> > --- a/drivers/tty/serial/8250/8250_mtk.c
> >> > +++ b/drivers/tty/serial/8250/8250_mtk.c
> >> > @@ -131,18 +131,16 @@ static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p,
> >> >                            struct mtk8250_data *data)
> >> >  {
> >> >         int err;
> >> > -       struct device_node *np = pdev->dev.of_node;
> >> >
> >> > -       data->uart_clk = of_clk_get(np, 0);
> >> > +       data->uart_clk = devm_clk_get(&pdev->dev, NULL);
> >> >         if (IS_ERR(data->uart_clk)) {
> >> > -               dev_warn(&pdev->dev, "Can't get timer clock\n");
> >> > +               dev_warn(&pdev->dev, "Can't get uart clock\n");
> >> >                 return PTR_ERR(data->uart_clk);
> >> >         }
> >> >
> >> >         err = clk_prepare_enable(data->uart_clk);
> >> >         if (err) {
> >> >                 dev_warn(&pdev->dev, "Can't prepare clock\n");
> >> > -               clk_put(data->uart_clk);
> >> >                 return err;
> >> >         }
> >> >         p->uartclk = clk_get_rate(data->uart_clk);
> >> > @@ -216,7 +214,6 @@ static int mtk8250_remove(struct platform_device *pdev)
> >> >         serial8250_unregister_port(data->line);
> >> >         if (!IS_ERR(data->uart_clk)) {
> >> >                 clk_disable_unprepare(data->uart_clk);
> >> > -               clk_put(data->uart_clk);
> >> >         }
> >>
> >> Please delete the braces.
> >
> > The if() is removed completly in the next patch anyway.
> 
> You are right. I propose to merge patch 2 and 3, so you get a clean code.

Patches 1 and 2 are different topics, I see no reason merging them. I
changed the order of the two patches, maybe this makes it better
readable.

> On the way, can you have a look on the commit message? For me it is
> not clear what you want to say.

Changed to:

    When a struct device * is present clk_get should be used rather
    than of_clk_get. Use the devm variant of this function to be able to
    drop the clk_put in the error and remove pathes. While at it fix
    a wrong error message.

Sascha


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