linux-kernel - Re: [Freedreno] [PATCH v2] drm/msm/dsi: Implement qcom, dsi-phy-regulator-ldo-mode for 28nm PHY

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Message-ID: <20191025140632.GH85762@art_vandelay>
Date:   Fri, 25 Oct 2019 10:06:32 -0400
From:   Sean Paul <sean@...rly.run>
To:     Stephan Gerhold <stephan@...hold.net>
Cc:     Rob Clark <robdclark@...il.com>, Sean Paul <sean@...rly.run>,
        Hai Li <hali@...eaurora.org>, David Airlie <airlied@...ux.ie>,
        linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org,
        dri-devel@...ts.freedesktop.org, Daniel Vetter <daniel@...ll.ch>,
        Nikita Travkin <nikitos.tr@...il.com>,
        freedreno@...ts.freedesktop.org
Subject: Re: [Freedreno] [PATCH v2] drm/msm/dsi: Implement qcom,
 dsi-phy-regulator-ldo-mode for 28nm PHY

On Wed, Oct 23, 2019 at 06:56:17PM +0200, Stephan Gerhold wrote:
> The DSI PHY regulator supports two regulator modes: LDO and DCDC.
> This mode can be selected using the "qcom,dsi-phy-regulator-ldo-mode"
> device tree property.
> 
> However, at the moment only the 20nm PHY driver actually implements
> that option. Add a check in the 28nm PHY driver to program the
> registers correctly for LDO mode.
> 
> Tested-by: Nikita Travkin <nikitos.tr@...il.com> # l8150
> Signed-off-by: Stephan Gerhold <stephan@...hold.net>

Thanks for your patch! I've pushed it to msm-next.

Sean

> ---
> Changes in v2: Move DCDC/LDO code into separate methods
> v1: https://lore.kernel.org/linux-arm-msm/20191021163425.83697-1-stephan@gerhold.net/
> 
> This is needed to make the display work on Longcheer L8150,
> which has recently gained mainline support in:
> https://git.kernel.org/pub/scm/linux/kernel/git/qcom/linux.git/commit/?id=16e8e8072108426029f0c16dff7fbe77fae3df8f
> 
> This patch is based on code from the downstream kernel:
> https://source.codeaurora.org/quic/la/kernel/msm-3.10/tree/drivers/video/msm/mdss/msm_mdss_io_8974.c?h=LA.BR.1.2.9.1-02310-8x16.0#n152
> 
> The LDO regulator configuration is taken from msm8916-qrd.dtsi:
> https://source.codeaurora.org/quic/la/kernel/msm-3.10/tree/arch/arm/boot/dts/qcom/msm8916-qrd.dtsi?h=LA.BR.1.2.9.1-02310-8x16.0#n56
> ---
>  drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm.c | 42 +++++++++++++++++-----
>  1 file changed, 34 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm.c b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm.c
> index b3f678f6c2aa..b384ea20f359 100644
> --- a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm.c
> +++ b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm.c
> @@ -39,15 +39,10 @@ static void dsi_28nm_dphy_set_timing(struct msm_dsi_phy *phy,
>  		DSI_28nm_PHY_TIMING_CTRL_11_TRIG3_CMD(0));
>  }
>  
> -static void dsi_28nm_phy_regulator_ctrl(struct msm_dsi_phy *phy, bool enable)
> +static void dsi_28nm_phy_regulator_enable_dcdc(struct msm_dsi_phy *phy)
>  {
>  	void __iomem *base = phy->reg_base;
>  
> -	if (!enable) {
> -		dsi_phy_write(base + REG_DSI_28nm_PHY_REGULATOR_CAL_PWR_CFG, 0);
> -		return;
> -	}
> -
>  	dsi_phy_write(base + REG_DSI_28nm_PHY_REGULATOR_CTRL_0, 0x0);
>  	dsi_phy_write(base + REG_DSI_28nm_PHY_REGULATOR_CAL_PWR_CFG, 1);
>  	dsi_phy_write(base + REG_DSI_28nm_PHY_REGULATOR_CTRL_5, 0);
> @@ -56,6 +51,39 @@ static void dsi_28nm_phy_regulator_ctrl(struct msm_dsi_phy *phy, bool enable)
>  	dsi_phy_write(base + REG_DSI_28nm_PHY_REGULATOR_CTRL_1, 0x9);
>  	dsi_phy_write(base + REG_DSI_28nm_PHY_REGULATOR_CTRL_0, 0x7);
>  	dsi_phy_write(base + REG_DSI_28nm_PHY_REGULATOR_CTRL_4, 0x20);
> +	dsi_phy_write(phy->base + REG_DSI_28nm_PHY_LDO_CNTRL, 0x00);
> +}
> +
> +static void dsi_28nm_phy_regulator_enable_ldo(struct msm_dsi_phy *phy)
> +{
> +	void __iomem *base = phy->reg_base;
> +
> +	dsi_phy_write(base + REG_DSI_28nm_PHY_REGULATOR_CTRL_0, 0x0);
> +	dsi_phy_write(base + REG_DSI_28nm_PHY_REGULATOR_CAL_PWR_CFG, 0);
> +	dsi_phy_write(base + REG_DSI_28nm_PHY_REGULATOR_CTRL_5, 0x7);
> +	dsi_phy_write(base + REG_DSI_28nm_PHY_REGULATOR_CTRL_3, 0);
> +	dsi_phy_write(base + REG_DSI_28nm_PHY_REGULATOR_CTRL_2, 0x1);
> +	dsi_phy_write(base + REG_DSI_28nm_PHY_REGULATOR_CTRL_1, 0x1);
> +	dsi_phy_write(base + REG_DSI_28nm_PHY_REGULATOR_CTRL_4, 0x20);
> +
> +	if (phy->cfg->type == MSM_DSI_PHY_28NM_LP)
> +		dsi_phy_write(phy->base + REG_DSI_28nm_PHY_LDO_CNTRL, 0x05);
> +	else
> +		dsi_phy_write(phy->base + REG_DSI_28nm_PHY_LDO_CNTRL, 0x0d);
> +}
> +
> +static void dsi_28nm_phy_regulator_ctrl(struct msm_dsi_phy *phy, bool enable)
> +{
> +	if (!enable) {
> +		dsi_phy_write(phy->reg_base +
> +			      REG_DSI_28nm_PHY_REGULATOR_CAL_PWR_CFG, 0);
> +		return;
> +	}
> +
> +	if (phy->regulator_ldo_mode)
> +		dsi_28nm_phy_regulator_enable_ldo(phy);
> +	else
> +		dsi_28nm_phy_regulator_enable_dcdc(phy);
>  }
>  
>  static int dsi_28nm_phy_enable(struct msm_dsi_phy *phy, int src_pll_id,
> @@ -77,8 +105,6 @@ static int dsi_28nm_phy_enable(struct msm_dsi_phy *phy, int src_pll_id,
>  
>  	dsi_28nm_phy_regulator_ctrl(phy, true);
>  
> -	dsi_phy_write(base + REG_DSI_28nm_PHY_LDO_CNTRL, 0x00);
> -
>  	dsi_28nm_dphy_set_timing(phy, timing);
>  
>  	dsi_phy_write(base + REG_DSI_28nm_PHY_CTRL_1, 0x00);
> -- 
> 2.23.0
> 
> _______________________________________________
> Freedreno mailing list
> Freedreno@...ts.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/freedreno

-- 
Sean Paul, Software Engineer, Google / Chromium OS

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