Re: [PATCH v7 07/21] iommu/mediatek: Add bclk can be supported optionally

From: Matthias Brugger <matthias.bgg@gmail.com>
To: Yong Wu <yong.wu@mediatek.com>, Joerg Roedel <joro@8bytes.org>,
	Robin Murphy <robin.murphy@arm.com>,
	Rob Herring <robh+dt@kernel.org>
Cc: youlin.pei@mediatek.com, devicetree@vger.kernel.org,
	Nicolas Boichat <drinkcat@chromium.org>,
	srv_heupstream@mediatek.com, Will Deacon <will.deacon@arm.com>,
	linux-kernel@vger.kernel.org, Evan Green <evgreen@chromium.org>,
	Tomasz Figa <tfiga@google.com>,
	iommu@lists.linux-foundation.org,
	Matthias Kaehlcke <mka@chromium.org>,
	linux-mediatek@lists.infradead.org, yingjoe.chen@mediatek.com,
	anan.sun@mediatek.com, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v7 07/21] iommu/mediatek: Add bclk can be supported optionally
Date: Sat, 15 Jun 2019 21:18:14 +0200	[thread overview]
Message-ID: <13f42053-cdc3-bef9-54f0-633880c41043@gmail.com> (raw)
In-Reply-To: <1560169080-27134-8-git-send-email-yong.wu@mediatek.com>


On 10/06/2019 14:17, Yong Wu wrote:
> In some SoCs, M4U doesn't have its "bclk", it will use the EMI
> clock instead which has always been enabled when entering kernel.
> 
> Currently mt2712 and mt8173 have this bclk while mt8183 doesn't.
> 
> This also is a preparing patch for mt8183.
> 
> Signed-off-by: Yong Wu <yong.wu@mediatek.com>
> Reviewed-by: Evan Green <evgreen@chromium.org>

Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>

> ---
>  drivers/iommu/mtk_iommu.c | 10 +++++++---
>  drivers/iommu/mtk_iommu.h |  3 +++
>  2 files changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> index aff5004..264dda4 100644
> --- a/drivers/iommu/mtk_iommu.c
> +++ b/drivers/iommu/mtk_iommu.c
> @@ -611,9 +611,11 @@ static int mtk_iommu_probe(struct platform_device *pdev)
>  	if (data->irq < 0)
>  		return data->irq;
>  
> -	data->bclk = devm_clk_get(dev, "bclk");
> -	if (IS_ERR(data->bclk))
> -		return PTR_ERR(data->bclk);
> +	if (data->plat_data->has_bclk) {
> +		data->bclk = devm_clk_get(dev, "bclk");
> +		if (IS_ERR(data->bclk))
> +			return PTR_ERR(data->bclk);
> +	}
>  
>  	larb_nr = of_count_phandle_with_args(dev->of_node,
>  					     "mediatek,larbs", NULL);
> @@ -741,11 +743,13 @@ static int __maybe_unused mtk_iommu_resume(struct device *dev)
>  static const struct mtk_iommu_plat_data mt2712_data = {
>  	.m4u_plat     = M4U_MT2712,
>  	.has_4gb_mode = true,
> +	.has_bclk     = true,
>  };
>  
>  static const struct mtk_iommu_plat_data mt8173_data = {
>  	.m4u_plat     = M4U_MT8173,
>  	.has_4gb_mode = true,
> +	.has_bclk     = true,
>  };
>  
>  static const struct of_device_id mtk_iommu_of_ids[] = {
> diff --git a/drivers/iommu/mtk_iommu.h b/drivers/iommu/mtk_iommu.h
> index d7a001a..63e235e 100644
> --- a/drivers/iommu/mtk_iommu.h
> +++ b/drivers/iommu/mtk_iommu.h
> @@ -43,6 +43,9 @@ enum mtk_iommu_plat {
>  struct mtk_iommu_plat_data {
>  	enum mtk_iommu_plat m4u_plat;
>  	bool                has_4gb_mode;
> +
> +	/* HW will use the EMI clock if there isn't the "bclk". */
> +	bool                has_bclk;
>  };
>  
>  struct mtk_iommu_domain;
> 

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