Re: [PATCH v2 1/6] usb: phy: mxs: enable regulator phy-3p0 to improve signal qualilty

From: Peter Chen <peter.chen@kernel.org>
To: Xu Yang <xu.yang_2@nxp.com>
Cc: vkoul@kernel.org, kishon@kernel.org, robh@kernel.org,
	krzk+dt@kernel.org, conor+dt@kernel.org, shawnguo@kernel.org,
	s.hauer@pengutronix.de, kernel@pengutronix.de,
	festevam@gmail.com, gregkh@linuxfoundation.org,
	herve.codina@bootlin.com, linux-phy@lists.infradead.org,
	devicetree@vger.kernel.org, imx@lists.linux.dev,
	linux-arm-kernel@lists.infradead.org, linux-usb@vger.kernel.org,
	jun.li@nxp.com
Subject: Re: [PATCH v2 1/6] usb: phy: mxs: enable regulator phy-3p0 to improve signal qualilty
Date: Fri, 9 Aug 2024 09:26:25 +0800	[thread overview]
Message-ID: <20240809012625.GC2673490@nchen-desktop> (raw)
In-Reply-To: <20240726113207.3393247-1-xu.yang_2@nxp.com>

On 24-07-26 19:32:02, Xu Yang wrote:
> Enable regulator 'phy-3p0' to pass eye diagram test since it improve signal
> qualilty.
> 
> Signed-off-by: Xu Yang <xu.yang_2@nxp.com>

Reviewed-by: Peter Chen <peter.chen@kernel.org>

> 
> ---
> Changes in v2:
>  - rewrite commit message
>  - use dev_err_probe() as suggested by Frank Li
> ---
>  drivers/usb/phy/phy-mxs-usb.c | 26 ++++++++++++++++++++++++++
>  1 file changed, 26 insertions(+)
> 
> diff --git a/drivers/usb/phy/phy-mxs-usb.c b/drivers/usb/phy/phy-mxs-usb.c
> index 920a32cd094d..d9d29f0b37de 100644
> --- a/drivers/usb/phy/phy-mxs-usb.c
> +++ b/drivers/usb/phy/phy-mxs-usb.c
> @@ -18,6 +18,7 @@
>  #include <linux/regmap.h>
>  #include <linux/mfd/syscon.h>
>  #include <linux/iopoll.h>
> +#include <linux/regulator/consumer.h>
>  
>  #define DRIVER_NAME "mxs_phy"
>  
> @@ -204,6 +205,7 @@ struct mxs_phy {
>  	int port_id;
>  	u32 tx_reg_set;
>  	u32 tx_reg_mask;
> +	struct regulator *phy_3p0;
>  };
>  
>  static inline bool is_imx6q_phy(struct mxs_phy *mxs_phy)
> @@ -288,6 +290,16 @@ static int mxs_phy_hw_init(struct mxs_phy *mxs_phy)
>  	if (ret)
>  		goto disable_pll;
>  
> +	if (mxs_phy->phy_3p0) {
> +		ret = regulator_enable(mxs_phy->phy_3p0);
> +		if (ret) {
> +			dev_err(mxs_phy->phy.dev,
> +				"Failed to enable 3p0 regulator, ret=%d\n",
> +				ret);
> +			return ret;
> +		}
> +	}
> +
>  	/* Power up the PHY */
>  	writel(0, base + HW_USBPHY_PWD);
>  
> @@ -448,6 +460,9 @@ static void mxs_phy_shutdown(struct usb_phy *phy)
>  	if (is_imx7ulp_phy(mxs_phy))
>  		mxs_phy_pll_enable(phy->io_priv, false);
>  
> +	if (mxs_phy->phy_3p0)
> +		regulator_disable(mxs_phy->phy_3p0);
> +
>  	clk_disable_unprepare(mxs_phy->clk);
>  }
>  
> @@ -789,6 +804,17 @@ static int mxs_phy_probe(struct platform_device *pdev)
>  	mxs_phy->clk = clk;
>  	mxs_phy->data = of_device_get_match_data(&pdev->dev);
>  
> +	mxs_phy->phy_3p0 = devm_regulator_get(&pdev->dev, "phy-3p0");
> +	if (PTR_ERR(mxs_phy->phy_3p0) == -ENODEV)
> +		/* not exist */
> +		mxs_phy->phy_3p0 = NULL;
> +	else if (IS_ERR(mxs_phy->phy_3p0))
> +		return dev_err_probe(&pdev->dev, PTR_ERR(mxs_phy->phy_3p0),
> +				"Getting regulator error\n");
> +
> +	if (mxs_phy->phy_3p0)
> +		regulator_set_voltage(mxs_phy->phy_3p0, 3200000, 3200000);
> +
>  	platform_set_drvdata(pdev, mxs_phy);
>  
>  	device_set_wakeup_capable(&pdev->dev, true);
> -- 
> 2.34.1
>