[PATCH 06/13] coresight: funnel: let runtime PM handle core clock

[Ulf Hansson]

On 17 April 2015 at 10:58, Linus Walleij <linus.walleij at linaro.org> wrote:
> This uses runtime PM to manage the PCLK ("amba_pclk") instead
> of screwing around with the framework by going in and taking
> a copy from the amba device. The amba bus core will uprepare
> and disable the clock when the device is unused when
> CONFIG_PM is selected, else the clock will be always on.
>
> Prior to this patch, as the AMBA primecell bus code enables
> the PCLK, it would be left on after probe as
> clk_disable_unprepare() was not called. Now the runtime PM
> callbacks will make sure the PCLK is properly disabled
> after probe.
>
> Signed-off-by: Linus Walleij <linus.walleij at linaro.org>

Reviewed-by: Ulf Hansson <ulf.hansson at linaro.org>

> ---
>  drivers/coresight/coresight-funnel.c | 24 +++++++-----------------
>  1 file changed, 7 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/coresight/coresight-funnel.c b/drivers/coresight/coresight-funnel.c
> index 3db36f70b666..330de2c88759 100644
> --- a/drivers/coresight/coresight-funnel.c
> +++ b/drivers/coresight/coresight-funnel.c
> @@ -18,7 +18,7 @@
>  #include <linux/err.h>
>  #include <linux/fs.h>
>  #include <linux/slab.h>
> -#include <linux/clk.h>
> +#include <linux/pm_runtime.h>
>  #include <linux/coresight.h>
>  #include <linux/amba/bus.h>
>
> @@ -36,14 +36,12 @@
>   * @base:      memory mapped base address for this component.
>   * @dev:       the device entity associated to this component.
>   * @csdev:     component vitals needed by the framework.
> - * @clk:       the clock this component is associated to.
>   * @priority:  port selection order.
>   */
>  struct funnel_drvdata {
>         void __iomem            *base;
>         struct device           *dev;
>         struct coresight_device *csdev;
> -       struct clk              *clk;
>         unsigned long           priority;
>  };
>
> @@ -67,12 +65,8 @@ static int funnel_enable(struct coresight_device *csdev, int inport,
>                          int outport)
>  {
>         struct funnel_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
> -       int ret;
> -
> -       ret = clk_prepare_enable(drvdata->clk);
> -       if (ret)
> -               return ret;
>
> +       pm_runtime_get_sync(drvdata->dev);
>         funnel_enable_hw(drvdata, inport);
>
>         dev_info(drvdata->dev, "FUNNEL inport %d enabled\n", inport);
> @@ -98,8 +92,7 @@ static void funnel_disable(struct coresight_device *csdev, int inport,
>         struct funnel_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>
>         funnel_disable_hw(drvdata, inport);
> -
> -       clk_disable_unprepare(drvdata->clk);
> +       pm_runtime_put(drvdata->dev);
>
>         dev_info(drvdata->dev, "FUNNEL inport %d disabled\n", inport);
>  }
> @@ -153,16 +146,14 @@ static u32 get_funnel_ctrl_hw(struct funnel_drvdata *drvdata)
>  static ssize_t funnel_ctrl_show(struct device *dev,
>                              struct device_attribute *attr, char *buf)
>  {
> -       int ret;
>         u32 val;
>         struct funnel_drvdata *drvdata = dev_get_drvdata(dev->parent);
>
> -       ret = clk_prepare_enable(drvdata->clk);
> -       if (ret)
> -               return ret;
> +       pm_runtime_get_sync(drvdata->dev);
>
>         val = get_funnel_ctrl_hw(drvdata);
> -       clk_disable_unprepare(drvdata->clk);
> +
> +       pm_runtime_put(drvdata->dev);
>
>         return sprintf(buf, "%#x\n", val);
>  }
> @@ -205,8 +196,7 @@ static int funnel_probe(struct amba_device *adev, const struct amba_id *id)
>                 return PTR_ERR(base);
>
>         drvdata->base = base;
> -
> -       drvdata->clk = adev->pclk;
> +       pm_runtime_put(&adev->dev);
>
>         desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
>         if (!desc)
> --
> 1.9.3
>