[PATCH v1 2/2] mtd: mtk-nor: add suspend/resume support

[Guochun Mao]

gentle ping...

On Thu, 2017-09-21 at 20:45 +0800, Guochun Mao wrote:
> Abstract functions of clock setting, to avoid duplicated code,
> these functions been used in new feature.
> Implement suspend/resume functions.
> 
> Signed-off-by: Guochun Mao <guochun.mao at mediatek.com>
> ---
>  drivers/mtd/spi-nor/mtk-quadspi.c |   70 ++++++++++++++++++++++++++++++-------
>  1 file changed, 58 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/mtd/spi-nor/mtk-quadspi.c b/drivers/mtd/spi-nor/mtk-quadspi.c
> index c258c7a..abe455c 100644
> --- a/drivers/mtd/spi-nor/mtk-quadspi.c
> +++ b/drivers/mtd/spi-nor/mtk-quadspi.c
> @@ -404,6 +404,29 @@ static int mt8173_nor_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf,
>  	return ret;
>  }
>  
> +static void mt8173_nor_disable_clk(struct mt8173_nor *mt8173_nor)
> +{
> +	clk_disable_unprepare(mt8173_nor->spi_clk);
> +	clk_disable_unprepare(mt8173_nor->nor_clk);
> +}
> +
> +static int mt8173_nor_enable_clk(struct mt8173_nor *mt8173_nor)
> +{
> +	int ret;
> +
> +	ret = clk_prepare_enable(mt8173_nor->spi_clk);
> +	if (ret)
> +		return ret;
> +
> +	ret = clk_prepare_enable(mt8173_nor->nor_clk);
> +	if (ret) {
> +		clk_disable_unprepare(mt8173_nor->spi_clk);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
>  static int mtk_nor_init(struct mt8173_nor *mt8173_nor,
>  			struct device_node *flash_node)
>  {
> @@ -468,15 +491,11 @@ static int mtk_nor_drv_probe(struct platform_device *pdev)
>  		return PTR_ERR(mt8173_nor->nor_clk);
>  
>  	mt8173_nor->dev = &pdev->dev;
> -	ret = clk_prepare_enable(mt8173_nor->spi_clk);
> +
> +	ret = mt8173_nor_enable_clk(mt8173_nor);
>  	if (ret)
>  		return ret;
>  
> -	ret = clk_prepare_enable(mt8173_nor->nor_clk);
> -	if (ret) {
> -		clk_disable_unprepare(mt8173_nor->spi_clk);
> -		return ret;
> -	}
>  	/* only support one attached flash */
>  	flash_np = of_get_next_available_child(pdev->dev.of_node, NULL);
>  	if (!flash_np) {
> @@ -487,10 +506,9 @@ static int mtk_nor_drv_probe(struct platform_device *pdev)
>  	ret = mtk_nor_init(mt8173_nor, flash_np);
>  
>  nor_free:
> -	if (ret) {
> -		clk_disable_unprepare(mt8173_nor->spi_clk);
> -		clk_disable_unprepare(mt8173_nor->nor_clk);
> -	}
> +	if (ret)
> +		mt8173_nor_disable_clk(mt8173_nor);
> +
>  	return ret;
>  }
>  
> @@ -498,11 +516,38 @@ static int mtk_nor_drv_remove(struct platform_device *pdev)
>  {
>  	struct mt8173_nor *mt8173_nor = platform_get_drvdata(pdev);
>  
> -	clk_disable_unprepare(mt8173_nor->spi_clk);
> -	clk_disable_unprepare(mt8173_nor->nor_clk);
> +	mt8173_nor_disable_clk(mt8173_nor);
> +
> +	return 0;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int mtk_nor_suspend(struct device *dev)
> +{
> +	struct mt8173_nor *mt8173_nor = dev_get_drvdata(dev);
> +
> +	mt8173_nor_disable_clk(mt8173_nor);
> +
>  	return 0;
>  }
>  
> +static int mtk_nor_resume(struct device *dev)
> +{
> +	struct mt8173_nor *mt8173_nor = dev_get_drvdata(dev);
> +
> +	return mt8173_nor_enable_clk(mt8173_nor);
> +}
> +
> +static const struct dev_pm_ops mtk_nor_dev_pm_ops = {
> +	.suspend = mtk_nor_suspend,
> +	.resume = mtk_nor_resume,
> +};
> +
> +#define MTK_NOR_DEV_PM_OPS	(&mtk_nor_dev_pm_ops)
> +#else
> +#define MTK_NOR_DEV_PM_OPS	NULL
> +#endif
> +
>  static const struct of_device_id mtk_nor_of_ids[] = {
>  	{ .compatible = "mediatek,mt8173-nor"},
>  	{ /* sentinel */ }
> @@ -514,6 +559,7 @@ static int mtk_nor_drv_remove(struct platform_device *pdev)
>  	.remove = mtk_nor_drv_remove,
>  	.driver = {
>  		.name = "mtk-nor",
> +		.pm = MTK_NOR_DEV_PM_OPS,
>  		.of_match_table = mtk_nor_of_ids,
>  	},
>  };