linux-kernel - Re: [PATCH v14 1/6] soc: mediatek: mutex: add common interface to accommodate multiple modules operationg MUTEX

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Message-ID: <0193f6b6-0019-3080-2615-02225eb4bf3b@collabora.com>
Date:   Wed, 13 Apr 2022 10:27:17 +0200
From:   AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@...labora.com>
To:     Moudy Ho <moudy.ho@...iatek.com>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Rob Herring <robh+dt@...nel.org>,
        Matthias Brugger <matthias.bgg@...il.com>,
        Hans Verkuil <hverkuil-cisco@...all.nl>,
        Jernej Skrabec <jernej.skrabec@...l.net>
Cc:     Chun-Kuang Hu <chunkuang.hu@...nel.org>,
        Geert Uytterhoeven <geert+renesas@...der.be>,
        Rob Landley <rob@...dley.net>,
        Laurent Pinchart <laurent.pinchart@...asonboard.com>,
        linux-media@...r.kernel.org, devicetree@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        linux-mediatek@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Alexandre Courbot <acourbot@...omium.org>, tfiga@...omium.org,
        drinkcat@...omium.org, pihsun@...omium.org, hsinyi@...gle.com,
        Benjamin Gaignard <benjamin.gaignard@...labora.com>,
        daoyuan huang <daoyuan.huang@...iatek.com>,
        Ping-Hsun Wu <ping-hsun.wu@...iatek.com>,
        allen-kh.cheng@...iatek.com, xiandong.wang@...iatek.com,
        randy.wu@...iatek.com, jason-jh.lin@...iatek.com,
        roy-cw.yeh@...iatek.com, river.cheng@...iatek.com,
        srv_heupstream@...iatek.com,
        Project_Global_Chrome_Upstream_Group@...iatek.com
Subject: Re: [PATCH v14 1/6] soc: mediatek: mutex: add common interface to
 accommodate multiple modules operationg MUTEX

Il 11/04/22 09:23, Moudy Ho ha scritto:
> In order to allow multiple modules to operate MUTEX hardware through
> a common interfrace, a flexible index "mtk_mutex_table_index" needs to
> be added to replace original component ID so that like DDP and MDP
> can add their own MUTEX table settings independently.
> 
> In addition, 4 generic interface "mtk_mutex_set_mod", "mtk_mutex_set_sof",
> "mtk_mutex_clear_mod" and "mtk_mutex_clear_sof" have been added, which is
> expected to replace the "mtk_mutex_add_comp" and "mtk_mutex_remove_comp"
> pair originally dedicated to DDP in the future.
> 
> Signed-off-by: Moudy Ho <moudy.ho@...iatek.com>
> Change-Id: I6a2ab74fccf36248165ce4a6b268d82a1177afc9
> ---
>   drivers/soc/mediatek/mtk-mutex.c       | 89 ++++++++++++++++++++++++++
>   include/linux/soc/mediatek/mtk-mutex.h | 21 ++++++
>   2 files changed, 110 insertions(+)
> 
> diff --git a/drivers/soc/mediatek/mtk-mutex.c b/drivers/soc/mediatek/mtk-mutex.c
> index aaf8fc1abb43..48a04dce50d5 100644
> --- a/drivers/soc/mediatek/mtk-mutex.c
> +++ b/drivers/soc/mediatek/mtk-mutex.c
> @@ -156,6 +156,8 @@ struct mtk_mutex_data {
>   	const unsigned int *mutex_sof;
>   	const unsigned int mutex_mod_reg;
>   	const unsigned int mutex_sof_reg;
> +	const unsigned int *mutex_table_mod;
> +	const unsigned int *mutex_table_sof;
>   	const bool no_clk;
>   };
>   
> @@ -445,6 +447,54 @@ void mtk_mutex_add_comp(struct mtk_mutex *mutex,
>   }
>   EXPORT_SYMBOL_GPL(mtk_mutex_add_comp);
>   

Hello Moudy,

Some critical things, and one cleanup.

First of all, the commit title is very long, and it also contains a typo.
I would go for something like
"soc: mediatek: mutex: Add common interface for modules setting".

Also, please remove your internal "Change-Id" tag, this is meaningless on
upstream, hence not applicable here.

Now for the cleanup: I have an idea to make this a bit shorter (and please
feel free to change function names with something more appropriate, if needed):

static int mtk_mutex_write_mod(struct mtk_mutex *mutex,
				enum mtk_mutex_table_index idx,
				bool clear)
{


> +{
> +	struct mtk_mutex_ctx *mtx = container_of(mutex, struct mtk_mutex_ctx,
> +						 mutex[mutex->id]);
> +	unsigned int reg;
> +	unsigned int offset;
> +
> +	WARN_ON(&mtx->mutex[mutex->id] != mutex);
> +
> +	if (idx < MUTEX_TABLE_IDX_MDP_RDMA0 ||
> +	    idx >= MUTEX_TABLE_IDX_MAX) {
> +		dev_err(mtx->dev, "Not supported MOD table index : %d", idx);
> +		return;

		return -EINVAL;

> +	}
> +
> +	offset = DISP_REG_MUTEX_MOD(mtx->data->mutex_mod_reg,
> +				    mutex->id);
> +
> +	reg = readl_relaxed(mtx->regs + offset);

if (clear)
	reg &= ~BIT(mtx->data->mutex_table_mod[idx])
else
	reg |= BIT(mtx->data->mutex_table_mod[idx])

> +	reg |= 1 << mtx->data->mutex_table_mod[idx];
> +	writel_relaxed(reg, mtx->regs + offset);
> +}

int mtk_mutex_set_mod(struct mtk_mutex *mutex,
		      enum mtk_mutex_table_index idx)
{
	return mtk_mutex_write_mod(mutex, idx, false);
}

int mtk_mutex_clear_mod(struct mtk_mutex *mutex,
			enum mtk_mutex_table_index idx)
{
	return mtk_mutex_clear_mod(mutex, idx, true);
}

> +EXPORT_SYMBOL_GPL(mtk_mutex_set_mod);
> +
> +void mtk_mutex_set_sof(struct mtk_mutex *mutex,
> +		       enum mtk_mutex_table_index idx)
> +{
> +	struct mtk_mutex_ctx *mtx = container_of(mutex, struct mtk_mutex_ctx,
> +						 mutex[mutex->id]);
> +	unsigned int sof_id;
> +
> +	WARN_ON(&mtx->mutex[mutex->id] != mutex);
> +
> +	if (idx < MUTEX_TABLE_IDX_MDP_RDMA0 ||
> +	    idx >= MUTEX_TABLE_IDX_MAX) {
> +		dev_err(mtx->dev, "Not supported SOF table index : %d", idx);
> +		return;
> +	}
> +
> +	sof_id = mtx->data->mutex_table_sof[idx];

... same changes here, except we'd have something like

if (clear)
	val = MUTEX_SOF_SINGLE_MODE;
else
	val = mtx->data->mutex_sof[sof_id];

	writel_relaxed(val, ...etc)

but feel free to give me valid reasons to not use this approach.

In any case, the code looks ok to me.


Regards,
Angelo