[PATCH] dmaengine: xgene-dma: Add ACPI support for X-Gene DMA engine driver

[Rameshwar Sahu]

Hi Vinod,

On Tue, Jul 21, 2015 at 6:44 PM, Rameshwar Prasad Sahu <rsahu at apm.com> wrote:
> This patch adds ACPI support for the APM X-Gene DMA engine driver.
>
> Signed-off-by: Rameshwar Prasad Sahu <rsahu at apm.com>
> ---
>  drivers/dma/xgene-dma.c | 28 +++++++++++++++++++++-------
>  1 file changed, 21 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/dma/xgene-dma.c b/drivers/dma/xgene-dma.c
> index dff22ab..d0a148d 100644
> --- a/drivers/dma/xgene-dma.c
> +++ b/drivers/dma/xgene-dma.c
> @@ -21,6 +21,7 @@
>   * NOTE: PM support is currently not available.
>   */
>
> +#include <linux/acpi.h>
>  #include <linux/clk.h>
>  #include <linux/delay.h>
>  #include <linux/dma-mapping.h>
> @@ -1944,16 +1945,18 @@ static int xgene_dma_probe(struct platform_device *pdev)
>                 return ret;
>
>         pdma->clk = devm_clk_get(&pdev->dev, NULL);
> -       if (IS_ERR(pdma->clk)) {
> +       if (IS_ERR(pdma->clk) && !ACPI_COMPANION(&pdev->dev)) {
>                 dev_err(&pdev->dev, "Failed to get clk\n");
>                 return PTR_ERR(pdma->clk);
>         }
>
>         /* Enable clk before accessing registers */
> -       ret = clk_prepare_enable(pdma->clk);
> -       if (ret) {
> -               dev_err(&pdev->dev, "Failed to enable clk %d\n", ret);
> -               return ret;
> +       if (!IS_ERR(pdma->clk)) {
> +               ret = clk_prepare_enable(pdma->clk);
> +               if (ret) {
> +                       dev_err(&pdev->dev, "Failed to enable clk %d\n", ret);
> +                       return ret;
> +               }
>         }
>
>         /* Remove DMA RAM out of shutdown */
> @@ -1998,7 +2001,8 @@ err_request_irq:
>
>  err_dma_mask:
>  err_clk_enable:
> -       clk_disable_unprepare(pdma->clk);
> +       if (!IS_ERR(pdma->clk))
> +               clk_disable_unprepare(pdma->clk);
>
>         return ret;
>  }
> @@ -2022,11 +2026,20 @@ static int xgene_dma_remove(struct platform_device *pdev)
>                 xgene_dma_delete_chan_rings(chan);
>         }
>
> -       clk_disable_unprepare(pdma->clk);
> +       if (!IS_ERR(pdma->clk))
> +               clk_disable_unprepare(pdma->clk);
>
>         return 0;
>  }
>
> +#ifdef CONFIG_ACPI
> +static const struct acpi_device_id xgene_dma_acpi_match_ptr[] = {
> +       {"APMC0D43", 0},
> +       {},
> +};
> +MODULE_DEVICE_TABLE(acpi, xgene_dma_acpi_match_ptr);
> +#endif
> +
>  static const struct of_device_id xgene_dma_of_match_ptr[] = {
>         {.compatible = "apm,xgene-storm-dma",},
>         {},
> @@ -2039,6 +2052,7 @@ static struct platform_driver xgene_dma_driver = {
>         .driver = {
>                 .name = "X-Gene-DMA",
>                 .of_match_table = xgene_dma_of_match_ptr,
> +               .acpi_match_table = ACPI_PTR(xgene_dma_acpi_match_ptr),
>         },
>  };
>
> --
> 1.8.2.1


Any Comments on the above patch ??