[PATCH 1/7] DMA: PL330: Add support runtime PM for PL330 DMAC

[Alim Akhtar]

Hi,

On Mon, Jul 4, 2011 at 5:48 PM, Kukjin Kim <kgene.kim at samsung.com> wrote:
> From: Boojin Kim <boojin.kim at samsung.com>
>
> Signed-off-by: Boojin Kim <boojin.kim at samsung.com>
> Cc: Vinod Koul <vinod.koul at intel.com>
> Cc: Dan Williams <dan.j.williams at intel.com>
> Signed-off-by: Kukjin Kim <kgene.kim at samsung.com>
> ---
>  drivers/dma/pl330.c |   61 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 61 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
> index 6abe1ec..7bd72e9 100644
> --- a/drivers/dma/pl330.c
> +++ b/drivers/dma/pl330.c
> @@ -17,6 +17,7 @@
>  #include <linux/interrupt.h>
>  #include <linux/amba/bus.h>
>  #include <linux/amba/pl330.h>
> +#include <linux/pm_runtime.h>
>
>  #define NR_DEFAULT_DESC        16
>
> @@ -666,6 +667,7 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
>        struct dma_device *pd;
>        struct resource *res;
>        int i, ret, irq;
> +       struct clk* clk;
>
>        pdat = adev->dev.platform_data;
>
> @@ -696,6 +698,28 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
>                goto probe_err1;
>        }
>
> +#ifdef CONFIG_PM_RUNTIME
> +       /* to use the runtime PM helper functions */
> +       pm_runtime_enable(&adev->dev);
> +
> +       /* enable the power domain */
> +       if (pm_runtime_get_sync(&adev->dev)) {
> +               dev_err(&adev->dev, "failed to get runtime pm\n");
> +               ret = -ENODEV;
> +               goto probe_err1;
> +       }
> +#else
> +       /* enable dma clk */
> +       clk = clk_get(&adev->dev, "dma");

Does this really needed here?
AFAIR, amba_get_enable_pclk() does the same thing, provided clock name
as "apb_pclk"
please have a look at drivers/amba/bus.c

> +
> +       if (IS_ERR(clk)) {
> +               dev_err(&adev->dev, "Cannot get operation clock.\n");
> +               ret = -EINVAL;
> +               goto probe_err1;
> +       }
> +       clk_enable(clk);
> +#endif
> +
>        irq = adev->irq[0];
>        ret = request_irq(irq, pl330_irq_handler, 0,
>                        dev_name(&adev->dev), pi);
> @@ -838,10 +862,47 @@ static struct amba_id pl330_ids[] = {
>        { 0, 0 },
>  };
>
> +#ifdef CONFIG_PM_RUNTIME
> +static int pl330_runtime_suspend(struct device *dev)
> +{
> +       struct clk *dmaclk = clk_get(dev, "dma");
> +
> +       if (dmaclk == NULL) {
> +               dev_err(dev, "failed to find dma clock source\n");
> +               return -ENODEV;
> +       }
> +
> +       clk_disable(dmaclk);
> +       return 0;
> +}
> +
> +static int pl330_runtime_resume(struct device *dev)
> +{
> +       struct clk *dmaclk = clk_get(dev, "dma");
> +
> +       if (dmaclk == NULL) {
> +               dev_err(dev, "failed to find dma clock source\n");
> +               return -ENODEV;
> +       }
> +
> +       clk_enable(dmaclk);
> +       return 0;
> +}
> +#else
> +#define pl330_runtime_suspend  NULL
> +#define pl330_runtime_resume   NULL
> +#endif /* CONFIG_PM_RUNTIME */
> +
> +static const struct dev_pm_ops pl330_pm_ops = {
> +       .runtime_suspend = pl330_runtime_suspend,
> +       .runtime_resume = pl330_runtime_resume,
> +};
> +
>  static struct amba_driver pl330_driver = {
>        .drv = {
>                .owner = THIS_MODULE,
>                .name = "dma-pl330",
> +               .pm = &pl330_pm_ops,
>        },
>        .id_table = pl330_ids,
>        .probe = pl330_probe,
> --
> 1.7.1
>
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