linux-kernel - Re: [PATCH v3 03/16] phy: qcom-qmp: Power-on PHY before initialization

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Message-ID: <1876f08f-818e-37aa-d080-ad97e03f5a3a@codeaurora.org>
Date:   Wed, 22 Nov 2017 10:03:52 -0800
From:   Stephen Boyd <sboyd@...eaurora.org>
To:     Manu Gautam <mgautam@...eaurora.org>,
        Kishon Vijay Abraham I <kishon@...com>
Cc:     linux-arm-msm@...r.kernel.org, linux-usb@...r.kernel.org,
        Vivek Gautam <vivek.gautam@...eaurora.org>,
        Varadarajan Narayanan <varada@...eaurora.org>,
        smuthayy <smuthayy@...eaurora.org>,
        Wei Yongjun <weiyongjun1@...wei.com>,
        Fengguang Wu <fengguang.wu@...el.com>,
        "open list:GENERIC PHY FRAMEWORK" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v3 03/16] phy: qcom-qmp: Power-on PHY before
 initialization

On 11/21/2017 01:23 AM, Manu Gautam wrote:
> PHY must be powered on before turning ON clocks and
> attempting to initialize it. Driver is exposing
> separate init and power_on routines for this.
> Apparently USB dwc3 core driver performs power-on after
> init. Also, poweron and init for QMP PHY need to be

Why does dwc3 driver power on after init? Seems backwards.

> executed together always, hence remove poweron callback
> from phy_ops and explicitly perform this from com_init,

Why do they need to be executed together?

> similar changes needed for poweroff. On similar lines move
> clk_enable from init to com_init which can be called once
> for multi lane PHYs.

Please add parenthesis, clk_enable() for example, to functions so we
know they're functions.

>
> Signed-off-by: Manu Gautam <mgautam@...eaurora.org>
> ---
>  drivers/phy/qualcomm/phy-qcom-qmp.c | 61 +++++++++++++------------------------
>  1 file changed, 21 insertions(+), 40 deletions(-)
>
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp.c b/drivers/phy/qualcomm/phy-qcom-qmp.c
> index 90794dd..2f427e3 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp.c
> @@ -720,33 +720,6 @@ static void qcom_qmp_phy_configure(void __iomem *base,
>  	}
>  }
>  
> -static int qcom_qmp_phy_poweron(struct phy *phy)
> -{
> -	struct qmp_phy *qphy = phy_get_drvdata(phy);
> -	struct qcom_qmp *qmp = qphy->qmp;
> -	int num = qmp->cfg->num_vregs;
> -	int ret;
> -
> -	dev_vdbg(&phy->dev, "Powering on QMP phy\n");
> -
> -	/* turn on regulator supplies */
> -	ret = regulator_bulk_enable(num, qmp->vregs);
> -	if (ret)
> -		dev_err(qmp->dev, "failed to enable regulators, err=%d\n", ret);
> -
> -	return ret;
> -}
> -
> -static int qcom_qmp_phy_poweroff(struct phy *phy)
> -{
> -	struct qmp_phy *qphy = phy_get_drvdata(phy);
> -	struct qcom_qmp *qmp = qphy->qmp;
> -
> -	regulator_bulk_disable(qmp->cfg->num_vregs, qmp->vregs);
> -
> -	return 0;
> -}
> -
>  static int qcom_qmp_phy_com_init(struct qcom_qmp *qmp)
>  {
>  	const struct qmp_phy_cfg *cfg = qmp->cfg;
> @@ -759,6 +732,19 @@ static int qcom_qmp_phy_com_init(struct qcom_qmp *qmp)
>  		return 0;
>  	}
>  
> +	/* turn on regulator supplies */
> +	ret = regulator_bulk_enable(cfg->num_vregs, qmp->vregs);
> +	if (ret) {
> +		mutex_unlock(&qmp->phy_mutex);
> +		return ret;

This could also be a goto.

> +	}
> +
> +	ret = clk_bulk_prepare_enable(cfg->num_clks, qmp->clks);
> +	if (ret) {
> +		dev_err(qmp->dev, "failed to enable clks, err=%d\n", ret);
> +		goto err_clk_enable;
> +	}
> +
>  	for (i = 0; i < cfg->num_resets; i++) {
>  		ret = reset_control_deassert(qmp->resets[i]);
>  		if (ret) {

-- 
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