Re: [PATCH 1/2] i2c: stu300: use clk_prepare/unprepare

[Shubhrajyoti Datta <omaplinuxkernel-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

Hi Linus,

On Tue, Jun 12, 2012 at 11:03 PM, Linus Walleij
<linus.walleij-0IS4wlFg1OjSUeElwK9/Pw@public.gmane.org> wrote:
> From: Linus Walleij <linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
>
> Make sure we prepare/unprepare the clock for the ST U300
> I2C driver as is required by the clk API especially if you
> use common clock.
Not a comment rather a doubt.

The transfer is still using enable and disable?
Can you help me understand the difference.

>
> Signed-off-by: Linus Walleij <linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
> ---
>  drivers/i2c/busses/i2c-stu300.c |    4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/i2c/busses/i2c-stu300.c b/drivers/i2c/busses/i2c-stu300.c
> index 4d44af1..79b7851 100644
> --- a/drivers/i2c/busses/i2c-stu300.c
> +++ b/drivers/i2c/busses/i2c-stu300.c
> @@ -924,7 +924,7 @@ stu300_probe(struct platform_device *pdev)
>
>        dev->speed = scl_frequency;
>
> -       clk_enable(dev->clk);
> +       clk_prepare_enable(dev->clk);
>        ret = stu300_init_hw(dev);
>        clk_disable(dev->clk);
>
> @@ -960,6 +960,7 @@ stu300_probe(struct platform_device *pdev)
>
>  err_add_adapter:
>  err_init_hw:
> +       clk_unprepare(dev->clk);

So this also fixes an earlier lack of disable also?

>        free_irq(dev->irq, dev);
>  err_no_irq:
>        iounmap(dev->virtbase);
> @@ -1016,6 +1017,7 @@ stu300_remove(struct platform_device *pdev)
>        free_irq(dev->irq, dev);
>        iounmap(dev->virtbase);
>        release_mem_region(dev->phybase, dev->physize);
> +       clk_unprepare(dev->clk);
>        clk_put(dev->clk);
>        platform_set_drvdata(pdev, NULL);
>        kfree(dev);
> --
> 1.7.9.2
>
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