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

Peter Chen
2024-08-09T01:27:21Z

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
>