linux-kernel - Re: [PATCH v3 10/14] phy: qcom: qmp-usbc: Add TCSR parsing and USB/DP mode mutex handling

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Message-ID: <i4rc5siu4q2o4sjk3j4bex7b7qdrs26y6lxsfnike7e7kqdva3@xddrd7vowtlb>
Date: Wed, 20 Aug 2025 14:24:00 +0300
From: Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>
To: Xiangxu Yin <xiangxu.yin@....qualcomm.com>
Cc: Rob Clark <robin.clark@....qualcomm.com>,
        Dmitry Baryshkov <lumag@...nel.org>,
        Abhinav Kumar <abhinav.kumar@...ux.dev>,
        Jessica Zhang <jessica.zhang@....qualcomm.com>,
        Sean Paul <sean@...rly.run>,
        Marijn Suijten <marijn.suijten@...ainline.org>,
        Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
        Maxime Ripard <mripard@...nel.org>,
        Thomas Zimmermann <tzimmermann@...e.de>,
        David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>,
        Rob Herring <robh@...nel.org>,
        Krzysztof Kozlowski <krzk+dt@...nel.org>,
        Conor Dooley <conor+dt@...nel.org>,
        Kuogee Hsieh <quic_khsieh@...cinc.com>, Vinod Koul <vkoul@...nel.org>,
        Kishon Vijay Abraham I <kishon@...nel.org>,
        Philipp Zabel <p.zabel@...gutronix.de>, linux-arm-msm@...r.kernel.org,
        dri-devel@...ts.freedesktop.org, freedreno@...ts.freedesktop.org,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-phy@...ts.infradead.org, fange.zhang@....qualcomm.com,
        yongxing.mou@....qualcomm.com, tingwei.zhang@....qualcomm.com,
        Bjorn Andersson <andersson@...nel.org>,
        Konrad Dybcio <konradybcio@...nel.org>, quic_lliu6@...cinc.com
Subject: Re: [PATCH v3 10/14] phy: qcom: qmp-usbc: Add TCSR parsing and
 USB/DP mode mutex handling

On Wed, Aug 20, 2025 at 05:34:52PM +0800, Xiangxu Yin wrote:
> Parse TCSR registers to support DP mode signaling via dp_phy_mode_reg.
> Introduce mutual exclusion between USB and DP PHY modes to prevent
> simultaneous activation. Also update com_init/com_exit to reflect DP
> mode initialization and cleanup.
> 
> Signed-off-by: Xiangxu Yin <xiangxu.yin@....qualcomm.com>
> ---
>  drivers/phy/qualcomm/phy-qcom-qmp-usbc.c | 60 +++++++++++++++++++++++++-------
>  1 file changed, 47 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-usbc.c b/drivers/phy/qualcomm/phy-qcom-qmp-usbc.c
> index a1495a2029cf038bb65c36e42d0a4f633e544558..821398653bef23e1915d9d3a3a2950b0bfbefb9a 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp-usbc.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-usbc.c
> @@ -674,7 +674,7 @@ static const struct qmp_phy_cfg qcs615_usb3dp_phy_cfg = {
>  	.num_vregs		= ARRAY_SIZE(qmp_phy_usbdp_vreg_l),
>  };
>  
> -static int qmp_usbc_com_init(struct phy *phy)
> +static int qmp_usbc_com_init(struct phy *phy, bool is_dp)
>  {
>  	struct qmp_usbc *qmp = phy_get_drvdata(phy);
>  	const struct qmp_phy_cfg *cfg = qmp->cfg;
> @@ -704,15 +704,20 @@ static int qmp_usbc_com_init(struct phy *phy)
>  	if (ret)
>  		goto err_assert_reset;
>  
> -	qphy_setbits(pcs, cfg->regs[QPHY_PCS_POWER_DOWN_CONTROL], SW_PWRDN);
> +	if (!is_dp) {
> +		qphy_setbits(pcs, cfg->regs[QPHY_PCS_POWER_DOWN_CONTROL], SW_PWRDN);

Why? Don't we need to program those bits for DP PHY too?

If not, move them to USB init call.

>  
>  #define SW_PORTSELECT_VAL			BIT(0)
>  #define SW_PORTSELECT_MUX			BIT(1)
> -	/* Use software based port select and switch on typec orientation */
> -	val = SW_PORTSELECT_MUX;
> -	if (qmp->orientation == TYPEC_ORIENTATION_REVERSE)
> -		val |= SW_PORTSELECT_VAL;
> -	writel(val, qmp->pcs_misc);
> +		/* Use software based port select and switch on typec orientation */
> +		val = SW_PORTSELECT_MUX;
> +		if (qmp->orientation == TYPEC_ORIENTATION_REVERSE)
> +			val |= SW_PORTSELECT_VAL;
> +		writel(val, qmp->pcs_misc);
> +	}
> +
> +	if (qmp->tcsr_map && qmp->dp_phy_mode_reg)
> +		regmap_write(qmp->tcsr_map, qmp->dp_phy_mode_reg, is_dp);

Write this reg directly from USB / DP init.

>  
>  	return 0;
>  
> @@ -733,6 +738,9 @@ static int qmp_usbc_com_exit(struct phy *phy)
>  
>  	clk_bulk_disable_unprepare(qmp->num_clks, qmp->clks);
>  
> +	if (qmp->tcsr_map && qmp->dp_phy_mode_reg)
> +		regmap_write(qmp->tcsr_map, qmp->dp_phy_mode_reg, 0);

Why?

> +
>  	regulator_bulk_disable(cfg->num_vregs, qmp->vregs);
>  
>  	return 0;
> @@ -1045,6 +1053,17 @@ static int qmp_usbc_usb_power_off(struct phy *phy)
>  	return 0;
>  }
>  
> +static int qmp_check_mutex_phy(struct qmp_usbc *qmp, bool is_dp)
> +{
> +	if ((is_dp && qmp->usb_init_count) ||
> +	    (!is_dp && qmp->dp_init_count)) {
> +		dev_err(qmp->dev, "%s PHY busy\n", is_dp ? "USB" : "DP");

"PHY is configured for %s, can not enable %s\n"

> +		return -EBUSY;
> +	}
> +
> +	return 0;
> +}
> +
>  static int qmp_usbc_usb_enable(struct phy *phy)
>  {
>  	struct qmp_usbc *qmp = phy_get_drvdata(phy);
> @@ -1052,7 +1071,11 @@ static int qmp_usbc_usb_enable(struct phy *phy)
>  
>  	mutex_lock(&qmp->phy_mutex);
>  
> -	ret = qmp_usbc_com_init(phy);
> +	ret = qmp_check_mutex_phy(qmp, false);
> +	if (ret)
> +		goto out_unlock;
> +
> +	ret = qmp_usbc_com_init(phy, false);
>  	if (ret)
>  		goto out_unlock;
>  
> @@ -1103,7 +1126,11 @@ static int qmp_usbc_dp_enable(struct phy *phy)
>  
>  	mutex_lock(&qmp->phy_mutex);
>  
> -	ret = qmp_usbc_com_init(phy);
> +	ret = qmp_check_mutex_phy(qmp, true);
> +	if (ret)
> +		goto dp_init_unlock;
> +
> +	ret = qmp_usbc_com_init(phy, true);
>  	if (ret)
>  		goto dp_init_unlock;
>  
> @@ -1467,7 +1494,7 @@ static int qmp_usbc_typec_switch_set(struct typec_switch_dev *sw,
>  		qmp_usbc_usb_power_off(qmp->usb_phy);
>  		qmp_usbc_com_exit(qmp->usb_phy);
>  
> -		qmp_usbc_com_init(qmp->usb_phy);
> +		qmp_usbc_com_init(qmp->usb_phy, false);
>  		qmp_usbc_usb_power_on(qmp->usb_phy);
>  	}
>  
> @@ -1602,13 +1629,13 @@ static int qmp_usbc_parse_usb_dt(struct qmp_usbc *qmp)
>  	return 0;
>  }
>  
> -static int qmp_usbc_parse_vls_clamp(struct qmp_usbc *qmp)
> +static int qmp_usbc_parse_tcsr(struct qmp_usbc *qmp)
>  {
>  	struct of_phandle_args tcsr_args;
>  	struct device *dev = qmp->dev;
>  	int ret;
>  
> -	/*  for backwards compatibility ignore if there is no property */
> +	/*  for backwards compatibility ignore if there is 1 or no property */
>  	ret = of_parse_phandle_with_fixed_args(dev->of_node, "qcom,tcsr-reg", 1, 0,
>  					       &tcsr_args);
>  	if (ret == -ENOENT)
> @@ -1623,6 +1650,13 @@ static int qmp_usbc_parse_vls_clamp(struct qmp_usbc *qmp)
>  
>  	qmp->vls_clamp_reg = tcsr_args.args[0];
>  
> +	ret = of_parse_phandle_with_fixed_args(dev->of_node, "qcom,tcsr-reg", 1, 1,
> +					       &tcsr_args);
> +	if (ret == -ENOENT)
> +		return 0;
> +
> +	qmp->dp_phy_mode_reg = tcsr_args.args[0];
> +
>  	return 0;
>  }
>  
> @@ -1665,7 +1699,7 @@ static int qmp_usbc_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
>  
> -	ret = qmp_usbc_parse_vls_clamp(qmp);
> +	ret = qmp_usbc_parse_tcsr(qmp);
>  	if (ret)
>  		return ret;
>  
> 
> -- 
> 2.34.1
> 

-- 
With best wishes
Dmitry