[alsa-devel] [PATCH 2/2] ASoC: rockchip: i2s: add support for grabbing output clock to codec

[Sonny Rao]

Jay,

On Tue, Nov 18, 2014 at 7:07 PM, Jianqun Xu <jay.xu at rock-chips.com> wrote:

Mostly FYI, but if you take someone else's patch, you should also
retain their authorship by saying:
From: <person>
at the top of the message. I don't really mind, but please keep it in
mind for the future, thanks.

> We need to claim the clock which is driving the codec so that when we enable
> clock gating, we continue to clock the codec when needed.  I make this an
> optional clock since there might be some applications where we don't need it
> but can still use the I2S block.
>
> Signed-off-by: Sonny Rao <sonnyrao at chromium.org>
> Signed-off-by: Jianqun Xu <jay.xu at rock-chips.com>
> ---
>  sound/soc/rockchip/rockchip_i2s.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
>
> diff --git a/sound/soc/rockchip/rockchip_i2s.c b/sound/soc/rockchip/rockchip_i2s.c
> index c74ba37..2820ade 100644
> --- a/sound/soc/rockchip/rockchip_i2s.c
> +++ b/sound/soc/rockchip/rockchip_i2s.c
> @@ -28,6 +28,7 @@ struct rk_i2s_dev {
>
>         struct clk *hclk;
>         struct clk *mclk;
> +       struct clk *oclk;
>
>         struct snd_dmaengine_dai_dma_data capture_dma_data;
>         struct snd_dmaengine_dai_dma_data playback_dma_data;
> @@ -439,6 +440,14 @@ static int rockchip_i2s_probe(struct platform_device *pdev)
>                 return PTR_ERR(i2s->mclk);
>         }
>
> +       i2s->oclk = devm_clk_get(&pdev->dev, "i2s_clk_out");
> +       if (IS_ERR(i2s->oclk)) {
> +               dev_dbg(&pdev->dev, "Didn't find output clock\n");
> +               i2s->oclk = NULL;
> +       }
> +       if (i2s->oclk)
> +               ret = clk_prepare_enable(i2s->oclk);
> +
>         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>         regs = devm_ioremap_resource(&pdev->dev, res);
>         if (IS_ERR(regs))
> @@ -505,6 +514,8 @@ static int rockchip_i2s_remove(struct platform_device *pdev)
>         if (!pm_runtime_status_suspended(&pdev->dev))
>                 i2s_runtime_suspend(&pdev->dev);
>
> +       if (i2s->oclk)
> +               clk_disable_unprepare(i2s->oclk);
>         clk_disable_unprepare(i2s->mclk);
>         clk_disable_unprepare(i2s->hclk);
>         snd_dmaengine_pcm_unregister(&pdev->dev);
> --
> 1.9.1
>