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Message-ID: <590f9a11-a153-abaf-0f99-9496882ee929@collabora.com>
Date:   Mon, 19 Jun 2023 11:29:18 +0200
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Subject: Re: [PATCH v5 6/8] soc: mediatek: Add support for WAY_EN operations
Content-Language: en-US
To:     Markus Schneider-Pargmann <msp@baylibre.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Matthias Brugger <matthias.bgg@gmail.com>
Cc:     Chun-Jie Chen <chun-jie.chen@mediatek.com>,
        Tinghan Shen <tinghan.shen@mediatek.com>,
        Fabien Parent <parent.f@gmail.com>, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org,
        Alexandre Bailon <abailon@baylibre.com>,
        Fabien Parent <fparent@baylibre.com>
References: <20230619085344.2885311-1-msp@baylibre.com>
 <20230619085344.2885311-7-msp@baylibre.com>
From:   AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>
In-Reply-To: <20230619085344.2885311-7-msp@baylibre.com>
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Precedence: bulk

Il 19/06/23 10:53, Markus Schneider-Pargmann ha scritto:
> From: Alexandre Bailon <abailon@baylibre.com>
> 
> This updates the power domain to support WAY_EN operations. WAY_EN
> operations on mt8365 are using a different component to check for the
> acknowledgment, namely the infracfg-nao component. Also to enable a way
> it the bit needs to be cleared while disabling a way needs a bit to be
> set. To support these two operations two flags are added,
> BUS_PROT_INVERTED and BUS_PROT_STA_COMPONENT_INFRA_NAO. Additionally
> another regmap is created if the INFRA_NAO capability is set.
> 
> This operation is required by the mt8365 for the MM power domain.
> 
> Signed-off-by: Alexandre Bailon <abailon@baylibre.com>
> Signed-off-by: Fabien Parent <fparent@baylibre.com>
> Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>
> ---
>   drivers/soc/mediatek/mtk-pm-domains.c | 39 +++++++++++++++++++++++----
>   drivers/soc/mediatek/mtk-pm-domains.h |  7 +++--
>   2 files changed, 39 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/soc/mediatek/mtk-pm-domains.c b/drivers/soc/mediatek/mtk-pm-domains.c
> index 3cdf62c0b6bd..4659f0a0aa08 100644
> --- a/drivers/soc/mediatek/mtk-pm-domains.c
> +++ b/drivers/soc/mediatek/mtk-pm-domains.c
> @@ -44,6 +44,7 @@ struct scpsys_domain {
>   	struct clk_bulk_data *clks;
>   	int num_subsys_clks;
>   	struct clk_bulk_data *subsys_clks;
> +	struct regmap *infracfg_nao;
>   	struct regmap *infracfg;
>   	struct regmap *smi;
>   	struct regulator *supply;
> @@ -127,13 +128,26 @@ static struct regmap *scpsys_bus_protect_get_regmap(struct scpsys_domain *pd,
>   		return pd->infracfg;
>   }
>   
> +static struct regmap *scpsys_bus_protect_get_sta_regmap(struct scpsys_domain *pd,
> +							const struct scpsys_bus_prot_data *bpd)
> +{
> +	if (bpd->flags & BUS_PROT_STA_COMPONENT_INFRA_NAO)
> +		return pd->infracfg_nao;
> +	else
> +		return scpsys_bus_protect_get_regmap(pd, bpd);
> +}
> +
>   static int scpsys_bus_protect_clear(struct scpsys_domain *pd,
>   				    const struct scpsys_bus_prot_data *bpd)
>   {
> +	struct regmap *sta_regmap = scpsys_bus_protect_get_sta_regmap(pd, bpd);
>   	struct regmap *regmap = scpsys_bus_protect_get_regmap(pd, bpd);
> +	u32 expected_ack;
>   	u32 val;
>   	u32 sta_mask = bpd->bus_prot_sta_mask;
>   
> +	expected_ack = (bpd->flags & BUS_PROT_STA_COMPONENT_INFRA_NAO ? sta_mask : 0);
> +
>   	if (bpd->flags & BUS_PROT_REG_UPDATE)
>   		regmap_clear_bits(regmap, bpd->bus_prot_clr, bpd->bus_prot_set_clr_mask);
>   	else
> @@ -142,14 +156,15 @@ static int scpsys_bus_protect_clear(struct scpsys_domain *pd,
>   	if (bpd->flags & BUS_PROT_IGNORE_CLR_ACK)
>   		return 0;
>   
> -	return regmap_read_poll_timeout(regmap, bpd->bus_prot_sta,
> -					val, !(val & sta_mask),
> +	return regmap_read_poll_timeout(sta_regmap, bpd->bus_prot_sta,
> +					val, (val & sta_mask) == expected_ack,
>   					MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
>   }
>   
>   static int scpsys_bus_protect_set(struct scpsys_domain *pd,
>   				  const struct scpsys_bus_prot_data *bpd)
>   {
> +	struct regmap *sta_regmap = scpsys_bus_protect_get_sta_regmap(pd, bpd);
>   	struct regmap *regmap = scpsys_bus_protect_get_regmap(pd, bpd);
>   	u32 val;
>   	u32 sta_mask = bpd->bus_prot_sta_mask;
> @@ -159,7 +174,7 @@ static int scpsys_bus_protect_set(struct scpsys_domain *pd,
>   	else
>   		regmap_write(regmap, bpd->bus_prot_set, bpd->bus_prot_set_clr_mask);
>   
> -	return regmap_read_poll_timeout(regmap, bpd->bus_prot_sta,
> +	return regmap_read_poll_timeout(sta_regmap, bpd->bus_prot_sta,
>   					val, (val & sta_mask) == sta_mask,
>   					MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
>   }
> @@ -173,7 +188,10 @@ static int scpsys_bus_protect_enable(struct scpsys_domain *pd)
>   		if (!bpd->bus_prot_set_clr_mask)
>   			break;
>   
> -		ret = scpsys_bus_protect_set(pd, bpd);
> +		if (bpd->flags & BUS_PROT_INVERTED)
> +			ret = scpsys_bus_protect_clear(pd, bpd);
> +		else
> +			ret = scpsys_bus_protect_set(pd, bpd);
>   		if (ret)
>   			return ret;
>   	}
> @@ -190,7 +208,10 @@ static int scpsys_bus_protect_disable(struct scpsys_domain *pd)
>   		if (!bpd->bus_prot_set_clr_mask)
>   			continue;
>   
> -		ret = scpsys_bus_protect_clear(pd, bpd);
> +		if (bpd->flags & BUS_PROT_INVERTED)
> +			ret = scpsys_bus_protect_set(pd, bpd);
> +		else
> +			ret = scpsys_bus_protect_clear(pd, bpd);
>   		if (ret)
>   			return ret;
>   	}
> @@ -377,6 +398,14 @@ generic_pm_domain *scpsys_add_one_domain(struct scpsys *scpsys, struct device_no
>   			return ERR_CAST(pd->smi);
>   	}
>   
> +	pd->infracfg_nao = syscon_regmap_lookup_by_phandle(node, "mediatek,infracfg-nao");

If we don't expect infracfg-nao to be present, what's the point about trying to
get a regmap handle and then failing only if we do expect it to be there?

At this point you can just do...

	if (MTK_SCPD_CAPS(pd, MTK_SCPD_HAS_INFRA_NAO)) {
		pd->infracfg_nao = syscon_regmap_lookup_by_phandle(...);
		if (IS_ERR(....))
			return ....
	}

> +	if (IS_ERR(pd->infracfg_nao)) {
> +		if (MTK_SCPD_CAPS(pd, MTK_SCPD_HAS_INFRA_NAO))
> +			return ERR_CAST(pd->infracfg_nao);
> +
> +		pd->infracfg_nao = NULL;
> +	}
> +
>   	num_clks = of_clk_get_parent_count(node);
>   	if (num_clks > 0) {
>   		/* Calculate number of subsys_clks */
> diff --git a/drivers/soc/mediatek/mtk-pm-domains.h b/drivers/soc/mediatek/mtk-pm-domains.h
> index 356788263db2..562d4e92ce16 100644
> --- a/drivers/soc/mediatek/mtk-pm-domains.h
> +++ b/drivers/soc/mediatek/mtk-pm-domains.h
> @@ -11,6 +11,7 @@
>   /* can't set MTK_SCPD_KEEP_DEFAULT_OFF at the same time */
>   #define MTK_SCPD_ALWAYS_ON		BIT(5)
>   #define MTK_SCPD_EXT_BUCK_ISO		BIT(6)
> +#define MTK_SCPD_HAS_INFRA_NAO		BIT(7)
>   #define MTK_SCPD_CAPS(_scpd, _x)	((_scpd)->data->caps & (_x))
>   
>   #define SPM_VDE_PWR_CON			0x0210
> @@ -45,8 +46,10 @@
>   enum scpsys_bus_prot_flags {
>   	BUS_PROT_REG_UPDATE = BIT(1),
>   	BUS_PROT_IGNORE_CLR_ACK = BIT(2),
> -	BUS_PROT_COMPONENT_INFRA = BIT(3),
> -	BUS_PROT_COMPONENT_SMI = BIT(4),
> +	BUS_PROT_INVERTED = BIT(3),

I get the reason why you're setting inverted as bit 3, but at that point you can
just set BUS_PROT_COMPONENT_INFRA to bit 4 from the very beginning, instead of
using bit 3 for that and then changing them all in a subsequent commit (this one).

Cheers,
Angelo