linux-kernel - Re: [PATCH v2 2/6] soc: mediatek: devapc: move 'vio_idx

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Message-ID: <39794302-7993-4f9c-b28c-577fdb0265a3@gmail.com>
Date:   Tue, 6 Apr 2021 15:41:40 +0200
From:   Matthias Brugger <matthias.bgg@...il.com>
To:     Nina Wu <nina-cm.wu@...iatek.com>, Rob Herring <robh+dt@...nel.org>
Cc:     Zhen Lei <thunder.leizhen@...wei.com>,
        Neal Liu <neal.liu@...iatek.com>, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-mediatek@...ts.infradead.org, srv_heupstream@...iatek.com,
        Jackson-kt.Chang@...iatek.com
Subject: Re: [PATCH v2 2/6] soc: mediatek: devapc: move 'vio_idx_num' info to
 DT



On 01/04/2021 08:38, Nina Wu wrote:
> From: Nina Wu <Nina-CM.Wu@...iatek.com>
> 
> For new ICs, there are multiple devapc HWs for different subsys.
> The number of devices controlled by each devapc (i.e. 'vio_idx_num'
> in the code) varies.
> We move this info from compatible data to DT so that we do not need
> to add n compatible for a certain IC which has n devapc HWs with
> different 'vio_idx_num', respectively.
> 
> Signed-off-by: Nina Wu <Nina-CM.Wu@...iatek.com>
> ---
>  drivers/soc/mediatek/mtk-devapc.c | 18 +++++++++---------
>  1 file changed, 9 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/soc/mediatek/mtk-devapc.c b/drivers/soc/mediatek/mtk-devapc.c
> index f1cea04..a0f6fbd 100644
> --- a/drivers/soc/mediatek/mtk-devapc.c
> +++ b/drivers/soc/mediatek/mtk-devapc.c
> @@ -32,9 +32,6 @@ struct mtk_devapc_vio_dbgs {
>  };
>  
>  struct mtk_devapc_data {
> -	/* numbers of violation index */
> -	u32 vio_idx_num;
> -
>  	/* reg offset */
>  	u32 vio_mask_offset;
>  	u32 vio_sta_offset;
> @@ -49,6 +46,7 @@ struct mtk_devapc_data {
>  struct mtk_devapc_context {
>  	struct device *dev;
>  	void __iomem *infra_base;
> +	u32 vio_idx_num;

We should try to stay backwards compatible (newer kernel with older DTS). I
think we don't need to move vio_idx_num to mtk_devapc_context. Just don't
declare it in the per SoC match data. More details see below...

>  	struct clk *infra_clk;
>  	const struct mtk_devapc_data *data;
>  };
> @@ -60,10 +58,10 @@ static void clear_vio_status(struct mtk_devapc_context *ctx)
>  
>  	reg = ctx->infra_base + ctx->data->vio_sta_offset;
>  
> -	for (i = 0; i < VIO_MOD_TO_REG_IND(ctx->data->vio_idx_num) - 1; i++)
> +	for (i = 0; i < VIO_MOD_TO_REG_IND(ctx->vio_idx_num - 1); i++)
>  		writel(GENMASK(31, 0), reg + 4 * i);
>  
> -	writel(GENMASK(VIO_MOD_TO_REG_OFF(ctx->data->vio_idx_num) - 1, 0),
> +	writel(GENMASK(VIO_MOD_TO_REG_OFF(ctx->vio_idx_num - 1), 0),
>  	       reg + 4 * i);
>  }
>  
> @@ -80,15 +78,15 @@ static void mask_module_irq(struct mtk_devapc_context *ctx, bool mask)
>  	else
>  		val = 0;
>  
> -	for (i = 0; i < VIO_MOD_TO_REG_IND(ctx->data->vio_idx_num) - 1; i++)
> +	for (i = 0; i < VIO_MOD_TO_REG_IND(ctx->vio_idx_num - 1); i++)
>  		writel(val, reg + 4 * i);
>  
>  	val = readl(reg + 4 * i);
>  	if (mask)
> -		val |= GENMASK(VIO_MOD_TO_REG_OFF(ctx->data->vio_idx_num) - 1,
> +		val |= GENMASK(VIO_MOD_TO_REG_OFF(ctx->vio_idx_num - 1),
>  			       0);
>  	else
> -		val &= ~GENMASK(VIO_MOD_TO_REG_OFF(ctx->data->vio_idx_num) - 1,
> +		val &= ~GENMASK(VIO_MOD_TO_REG_OFF(ctx->vio_idx_num - 1),
>  				0);
>  
>  	writel(val, reg + 4 * i);
> @@ -216,7 +214,6 @@ static void stop_devapc(struct mtk_devapc_context *ctx)
>  }
>  
>  static const struct mtk_devapc_data devapc_mt6779 = {
> -	.vio_idx_num = 511,
>  	.vio_mask_offset = 0x0,
>  	.vio_sta_offset = 0x400,
>  	.vio_dbg0_offset = 0x900,
> @@ -256,6 +253,9 @@ static int mtk_devapc_probe(struct platform_device *pdev)
>  	if (!ctx->infra_base)
>  		return -EINVAL;
>  
> +	if (of_property_read_u32(node, "vio_idx_num", &ctx->vio_idx_num))
> +		return -EINVAL;
> +

...only read the property if  vio_idx_num == 0.
What do you think?

Regards,
Matthias

>  	devapc_irq = irq_of_parse_and_map(node, 0);
>  	if (!devapc_irq)
>  		return -EINVAL;
>