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Date:   Mon, 16 Oct 2023 13:34:42 +0200
From:   Sascha Hauer <s.hauer@pengutronix.de>
To:     Chanwoo Choi <chanwoo@kernel.org>
Cc:     linux-rockchip@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-pm@vger.kernel.org, Heiko Stuebner <heiko@sntech.de>,
        Kyungmin Park <kyungmin.park@samsung.com>,
        MyungJoo Ham <myungjoo.ham@samsung.com>,
        Will Deacon <will@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>, kernel@pengutronix.de,
        Michael Riesch <michael.riesch@wolfvision.net>,
        Robin Murphy <robin.murphy@arm.com>,
        Vincent Legoll <vincent.legoll@gmail.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>, devicetree@vger.kernel.org,
        Sebastian Reichel <sebastian.reichel@collabora.com>
Subject: Re: [PATCH v7 10/26] PM / devfreq: rockchip-dfi: Add RK3568 support
Message-ID: <20231016113442.GZ3359458@pengutronix.de>
References: <20230704093242.583575-1-s.hauer@pengutronix.de>
 <20230704093242.583575-11-s.hauer@pengutronix.de>
 <ac224dfe-ff7d-57c7-89ad-f10939975b4d@kernel.org>
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On Sat, Oct 07, 2023 at 03:17:14AM +0900, Chanwoo Choi wrote:
> On 23. 7. 4. 18:32, Sascha Hauer wrote:
> > This adds RK3568 support to the DFI driver.  Only iniitialization
> > differs from the currently supported RK3399.
> > 
> > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> > ---
> >  drivers/devfreq/event/rockchip-dfi.c | 21 +++++++++++++++++++++
> >  include/soc/rockchip/rk3568_grf.h    | 12 ++++++++++++
> >  2 files changed, 33 insertions(+)
> >  create mode 100644 include/soc/rockchip/rk3568_grf.h
> > 
> > diff --git a/drivers/devfreq/event/rockchip-dfi.c b/drivers/devfreq/event/rockchip-dfi.c
> > index 6b3ef97b3be09..261d112580c9e 100644
> > --- a/drivers/devfreq/event/rockchip-dfi.c
> > +++ b/drivers/devfreq/event/rockchip-dfi.c
> > @@ -23,6 +23,7 @@
> >  
> >  #include <soc/rockchip/rockchip_grf.h>
> >  #include <soc/rockchip/rk3399_grf.h>
> > +#include <soc/rockchip/rk3568_grf.h>
> >  
> >  #define DMC_MAX_CHANNELS	2
> >  
> > @@ -209,10 +210,30 @@ static int rk3399_dfi_init(struct rockchip_dfi *dfi)
> >  	return 0;
> >  };
> >  
> > +static int rk3568_dfi_init(struct rockchip_dfi *dfi)
> > +{
> > +	struct regmap *regmap_pmu = dfi->regmap_pmu;
> > +	u32 reg2, reg3;
> > +
> > +	regmap_read(regmap_pmu, RK3568_PMUGRF_OS_REG2, &reg2);
> > +	regmap_read(regmap_pmu, RK3568_PMUGRF_OS_REG3, &reg3);
> > +
> > +	dfi->ddr_type = FIELD_GET(RK3568_PMUGRF_OS_REG2_DRAMTYPE_INFO, reg2);

The ddr_type is 5 bits wide. The lower three bits are here.

> > +
> > +	if (FIELD_GET(RK3568_PMUGRF_OS_REG3_SYSREG_VERSION, reg3) >= 0x3)
> > +		dfi->ddr_type |= FIELD_GET(RK3568_PMUGRF_OS_REG3_DRAMTYPE_INFO_V3, reg3) << 3;

The upper two bits are here, hence we need to shift the value above the
lower three bits.

> 
> There are no reason of why shifting the '3'.
> Could you add the comment about '3' or add the constant definition '3'?

I don't think adding a constant makes sense. I'll add a comment making
it more clear what happens.

> 
> > +
> > +	dfi->channel_mask = 1;
> 
> nitpick.
> On other rkXXXX_dfi_init, use GENMASK() to initialize 'dfi->channel_mask'.
> In order to keep the consistency, it is better to use BIT() macro as following:
> 	dfi->channel_mask = BIT(0);

Ok, will do.

Sascha

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