Re: [PATCH V3 1/3] ASoC: fsl_esai: spba clock is needed by esai device

From: Rob Herring
Date: Tue Nov 24 2015 - 18:21:43 EST


On Tue, Nov 24, 2015 at 03:03:28PM +0800, Shengjiu Wang wrote:
> ESAI need to enable the spba clock, when sdma is using share peripheral
> script. In this case, there is two spba master port is used, if don't
> enable the clock, the spba bus will have arbitration issue, which may
> cause read/write wrong data from/to ESAI registers.
>
> Signed-off-by: Shengjiu Wang <shengjiu.wang@xxxxxxxxxxxxx>
> ---
> Documentation/devicetree/bindings/sound/fsl,esai.txt | 5 +++++

Acked-by: Rob Herring <robh@xxxxxxxxxx>

> sound/soc/fsl/fsl_esai.c | 13 +++++++++++++
> 2 files changed, 18 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/sound/fsl,esai.txt b/Documentation/devicetree/bindings/sound/fsl,esai.txt
> index d3b6b5f..cd3ee5d 100644
> --- a/Documentation/devicetree/bindings/sound/fsl,esai.txt
> +++ b/Documentation/devicetree/bindings/sound/fsl,esai.txt
> @@ -27,6 +27,11 @@ Required properties:
> derive HCK, SCK and FS.
> "fsys" The system clock derived from ahb clock used to
> derive HCK, SCK and FS.
> + "spba" The spba clock is required when ESAI is placed as a
> + bus slave of the Shared Peripheral Bus and when two
> + or more bus masters (CPU, DMA or DSP) try to access
> + it. This property is optional depending on the SoC
> + design.
>
> - fsl,fifo-depth : The number of elements in the transmit and receive
> FIFOs. This number is the maximum allowed value for
> diff --git a/sound/soc/fsl/fsl_esai.c b/sound/soc/fsl/fsl_esai.c
> index 504e731..4d7589c 100644
> --- a/sound/soc/fsl/fsl_esai.c
> +++ b/sound/soc/fsl/fsl_esai.c
> @@ -35,6 +35,7 @@
> * @coreclk: clock source to access register
> * @extalclk: esai clock source to derive HCK, SCK and FS
> * @fsysclk: system clock source to derive HCK, SCK and FS
> + * @spbaclk: SPBA clock (optional, depending on SoC design)
> * @fifo_depth: depth of tx/rx FIFO
> * @slot_width: width of each DAI slot
> * @slots: number of slots
> @@ -54,6 +55,7 @@ struct fsl_esai {
> struct clk *coreclk;
> struct clk *extalclk;
> struct clk *fsysclk;
> + struct clk *spbaclk;
> u32 fifo_depth;
> u32 slot_width;
> u32 slots;
> @@ -469,6 +471,9 @@ static int fsl_esai_startup(struct snd_pcm_substream *substream,
> ret = clk_prepare_enable(esai_priv->coreclk);
> if (ret)
> return ret;
> + ret = clk_prepare_enable(esai_priv->spbaclk);
> + if (ret)
> + goto err_spbaclk;
> if (!IS_ERR(esai_priv->extalclk)) {
> ret = clk_prepare_enable(esai_priv->extalclk);
> if (ret)
> @@ -499,6 +504,8 @@ err_fsysclk:
> if (!IS_ERR(esai_priv->extalclk))
> clk_disable_unprepare(esai_priv->extalclk);
> err_extalck:
> + clk_disable_unprepare(esai_priv->spbaclk);
> +err_spbaclk:
> clk_disable_unprepare(esai_priv->coreclk);
>
> return ret;
> @@ -564,6 +571,7 @@ static void fsl_esai_shutdown(struct snd_pcm_substream *substream,
> clk_disable_unprepare(esai_priv->fsysclk);
> if (!IS_ERR(esai_priv->extalclk))
> clk_disable_unprepare(esai_priv->extalclk);
> + clk_disable_unprepare(esai_priv->spbaclk);
> clk_disable_unprepare(esai_priv->coreclk);
> }
>
> @@ -819,6 +827,11 @@ static int fsl_esai_probe(struct platform_device *pdev)
> dev_warn(&pdev->dev, "failed to get fsys clock: %ld\n",
> PTR_ERR(esai_priv->fsysclk));
>
> + esai_priv->spbaclk = devm_clk_get(&pdev->dev, "spba");
> + if (IS_ERR(esai_priv->spbaclk))
> + dev_warn(&pdev->dev, "failed to get spba clock: %ld\n",
> + PTR_ERR(esai_priv->spbaclk));
> +
> irq = platform_get_irq(pdev, 0);
> if (irq < 0) {
> dev_err(&pdev->dev, "no irq for node %s\n", pdev->name);
> --
> 1.9.1
>
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