RE: [PATCH v8 18/26] PM / devfreq: rockchip-dfi: account for multiple DDRMON_CTRL registers

["Chanwoo Choi" <cw00.choi@samsung.com>]

> -----Original Message-----
> From: Chanwoo Choi <chanwoo@kernel.org>
> Sent: Thursday, October 19, 2023 12:12 AM
> To: Sascha Hauer <s.hauer@pengutronix.de>; linux-
> rockchip@lists.infradead.org
> Cc: 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>; Jonathan Cameron
> <Jonathan.Cameron@huawei.com>
> Subject: Re: [PATCH v8 18/26] PM / devfreq: rockchip-dfi: account for
> multiple DDRMON_CTRL registers
> 
> On 23. 10. 18. 15:17, Sascha Hauer wrote:
> > The currently supported RK3399 has a set of registers per channel, but
> > it has only a single DDRMON_CTRL register. With upcoming RK3588 this
> > will be different, the RK3588 has a DDRMON_CTRL register per channel.
> >
> > Instead of expecting a single DDRMON_CTRL register, loop over the
> > channels and write the channel specific DDRMON_CTRL register. Break
> > out early out of the loop when there is only a single DDRMON_CTRL
> > register like on the RK3399.
> >
> > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> > Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
> > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> > ---
> >
> > Notes:
> >     Changes since v7:
> >      - initialize ddrmon_ctrl_single for RK3568
> >
> >  drivers/devfreq/event/rockchip-dfi.c | 73
> > +++++++++++++++++++---------
> >  1 file changed, 49 insertions(+), 24 deletions(-)
> >
> > diff --git a/drivers/devfreq/event/rockchip-dfi.c
> > b/drivers/devfreq/event/rockchip-dfi.c
> > index a3d823ac68ace..bf38829a2a4af 100644
> > --- a/drivers/devfreq/event/rockchip-dfi.c
> > +++ b/drivers/devfreq/event/rockchip-dfi.c
> > @@ -114,12 +114,13 @@ struct rockchip_dfi {
> >  	int burst_len;
> >  	int buswidth[DMC_MAX_CHANNELS];
> >  	int ddrmon_stride;
> > +	bool ddrmon_ctrl_single;
> >  };
> >
> >  static int rockchip_dfi_enable(struct rockchip_dfi *dfi)  {
> >  	void __iomem *dfi_regs = dfi->regs;
> > -	int ret = 0;
> > +	int i, ret = 0;
> >
> >  	mutex_lock(&dfi->mutex);
> >
> > @@ -133,29 +134,41 @@ static int rockchip_dfi_enable(struct rockchip_dfi
> *dfi)
> >  		goto out;
> >  	}
> >
> > -	/* clear DDRMON_CTRL setting */
> > -	writel_relaxed(HIWORD_UPDATE(0, DDRMON_CTRL_TIMER_CNT_EN |
> DDRMON_CTRL_SOFTWARE_EN |
> > -		       DDRMON_CTRL_HARDWARE_EN), dfi_regs + DDRMON_CTRL);
> > +	for (i = 0; i < dfi->max_channels; i++) {
> > +		u32 ctrl = 0;
> >
> > -	/* set ddr type to dfi */
> > -	switch (dfi->ddr_type) {
> > -	case ROCKCHIP_DDRTYPE_LPDDR2:
> > -	case ROCKCHIP_DDRTYPE_LPDDR3:
> > -		writel_relaxed(HIWORD_UPDATE(DDRMON_CTRL_LPDDR23,
> DDRMON_CTRL_DDR_TYPE_MASK),
> > -			       dfi_regs + DDRMON_CTRL);
> > -		break;
> > -	case ROCKCHIP_DDRTYPE_LPDDR4:
> > -	case ROCKCHIP_DDRTYPE_LPDDR4X:
> > -		writel_relaxed(HIWORD_UPDATE(DDRMON_CTRL_LPDDR4,
> DDRMON_CTRL_DDR_TYPE_MASK),
> > -			       dfi_regs + DDRMON_CTRL);
> > -		break;
> > -	default:
> > -		break;
> > -	}
> > +		if (!(dfi->channel_mask & BIT(i)))
> > +			continue;
> >
> > -	/* enable count, use software mode */
> > -	writel_relaxed(HIWORD_UPDATE(DDRMON_CTRL_SOFTWARE_EN,
> DDRMON_CTRL_SOFTWARE_EN),
> > -		       dfi_regs + DDRMON_CTRL);
> > +		/* clear DDRMON_CTRL setting */
> > +		writel_relaxed(HIWORD_UPDATE(0, DDRMON_CTRL_TIMER_CNT_EN |
> > +			       DDRMON_CTRL_SOFTWARE_EN |
> DDRMON_CTRL_HARDWARE_EN),
> > +			       dfi_regs + i * dfi->ddrmon_stride + DDRMON_CTRL);
> > +
> > +		/* set ddr type to dfi */
> > +		switch (dfi->ddr_type) {
> > +		case ROCKCHIP_DDRTYPE_LPDDR2:
> > +		case ROCKCHIP_DDRTYPE_LPDDR3:
> > +			ctrl = DDRMON_CTRL_LPDDR23;
> > +			break;
> > +		case ROCKCHIP_DDRTYPE_LPDDR4:
> > +		case ROCKCHIP_DDRTYPE_LPDDR4X:
> > +			ctrl = DDRMON_CTRL_LPDDR4;
> > +			break;
> > +		default:
> > +			break;
> > +		}
> > +
> > +		writel_relaxed(HIWORD_UPDATE(ctrl,
> DDRMON_CTRL_DDR_TYPE_MASK),
> > +			       dfi_regs + i * dfi->ddrmon_stride + DDRMON_CTRL);
> > +
> > +		/* enable count, use software mode */
> > +		writel_relaxed(HIWORD_UPDATE(DDRMON_CTRL_SOFTWARE_EN,
> DDRMON_CTRL_SOFTWARE_EN),
> > +			       dfi_regs + i * dfi->ddrmon_stride + DDRMON_CTRL);
> > +
> > +		if (dfi->ddrmon_ctrl_single)
> > +			break;
> > +	}
> >  out:
> >  	mutex_unlock(&dfi->mutex);
> >
> > @@ -165,6 +178,7 @@ static int rockchip_dfi_enable(struct rockchip_dfi
> > *dfi)  static void rockchip_dfi_disable(struct rockchip_dfi *dfi)  {
> >  	void __iomem *dfi_regs = dfi->regs;
> > +	int i;
> >
> >  	mutex_lock(&dfi->mutex);
> >
> > @@ -175,8 +189,17 @@ static void rockchip_dfi_disable(struct
> rockchip_dfi *dfi)
> >  	if (dfi->usecount > 0)
> >  		goto out;
> >
> > -	writel_relaxed(HIWORD_UPDATE(0, DDRMON_CTRL_SOFTWARE_EN),
> > -		       dfi_regs + DDRMON_CTRL);
> > +	for (i = 0; i < dfi->max_channels; i++) {
> > +		if (!(dfi->channel_mask & BIT(i)))
> > +			continue;
> > +
> > +		writel_relaxed(HIWORD_UPDATE(0, DDRMON_CTRL_SOFTWARE_EN),
> > +			      dfi_regs + i * dfi->ddrmon_stride + DDRMON_CTRL);
> > +
> > +		if (dfi->ddrmon_ctrl_single)
> > +			break;
> > +	}
> > +
> >  	clk_disable_unprepare(dfi->clk);
> >  out:
> >  	mutex_unlock(&dfi->mutex);
> > @@ -666,6 +689,7 @@ static int rk3399_dfi_init(struct rockchip_dfi *dfi)
> >  	dfi->buswidth[1] = FIELD_GET(RK3399_PMUGRF_OS_REG2_BW_CH1, val) ==
> 0
> > ? 4 : 2;
> >
> >  	dfi->ddrmon_stride = 0x14;
> > +	dfi->ddrmon_ctrl_single = true;
> >
> >  	return 0;
> >  };
> > @@ -694,6 +718,7 @@ static int rk3568_dfi_init(struct rockchip_dfi *dfi)
> >  	dfi->buswidth[0] = FIELD_GET(RK3568_PMUGRF_OS_REG2_BW_CH0, reg2) ==
> > 0 ? 4 : 2;
> >
> >  	dfi->ddrmon_stride = 0x0; /* not relevant, we only have a single
> > channel on this SoC */
> > +	dfi->ddrmon_ctrl_single = true;
> >
> >  	return 0;
> >  };
> 
> Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
> 
> --
> Best Regards,
> Samsung Electronics
> Chanwoo Choi


Applied it. Thanks

Best Regards,
Chanwoo Choi