Re: [PATCH v2] phy: fsl-imx8mq-usb: enable RxTermination_override_sel

[Vinod Koul <vkoul@kernel.org>]

On 24-12-25, 19:18, Xu Yang wrote:

What is the with the CamelCase on the patch title! We dont do that
please

> This is to resolve the problem of wakeup system by USB3 device insertion
> if HSIOMIX on, in that case, the USB3 device detects RX term on so the
> USB3 device doesn't downgrade to high-speed, we can't expect CONN wakeup
> (for USB3) happen because the 24MHz OSC is required ON to trigger it.
> Because the device works at Super-speed so DP/DM wakeup can't happen
> either. Then the entire systen can't be waken up by such device attach
> event.
> 
> With this override bit we can force the RX term off when enters system
> suspend, and disable the override after system resume. Therefore, the
> USB3 device will always downgrade to High-speed, then DP/DM wakeup can
> always happen. It will correctly switch to Super-speed later when the
> host reset it after the system resume back.
> 
> Signed-off-by: Li Jun <jun.li@nxp.com>
> Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
> 
> ---
> Changes in v2:
>  - rephase the message
> ---
>  drivers/phy/freescale/phy-fsl-imx8mq-usb.c | 15 ++++++++++++++-
>  1 file changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/phy/freescale/phy-fsl-imx8mq-usb.c b/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
> index 92c5c233bad9..e991a480b882 100644
> --- a/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
> +++ b/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
> @@ -51,6 +51,7 @@
>  #define PHY_CTRL5_PCS_TX_SWING_FULL_MASK	GENMASK(6, 0)
>  
>  #define PHY_CTRL6			0x18
> +#define PHY_CTRL6_RXTERM_OVERRIDE_SEL	BIT(29)
>  #define PHY_CTRL6_ALT_CLK_EN		BIT(1)
>  #define PHY_CTRL6_ALT_CLK_SEL		BIT(0)
>  
> @@ -630,6 +631,7 @@ static int imx8mp_usb_phy_init(struct phy *phy)
>  static int imx8mq_phy_power_on(struct phy *phy)
>  {
>  	struct imx8mq_usb_phy *imx_phy = phy_get_drvdata(phy);
> +	u32 value;
>  	int ret;
>  
>  	ret = regulator_enable(imx_phy->vbus);
> @@ -646,12 +648,23 @@ static int imx8mq_phy_power_on(struct phy *phy)
>  		return ret;
>  	}
>  
> -	return ret;
> +	/* Disable rx term override */
> +	value = readl(imx_phy->base + PHY_CTRL6);
> +	value &= ~PHY_CTRL6_RXTERM_OVERRIDE_SEL;
> +	writel(value, imx_phy->base + PHY_CTRL6);
> +
> +	return 0;
>  }
>  
>  static int imx8mq_phy_power_off(struct phy *phy)
>  {
>  	struct imx8mq_usb_phy *imx_phy = phy_get_drvdata(phy);
> +	u32 value;
> +
> +	/* Override rx term to be 0 */
> +	value = readl(imx_phy->base + PHY_CTRL6);
> +	value |= PHY_CTRL6_RXTERM_OVERRIDE_SEL;
> +	writel(value, imx_phy->base + PHY_CTRL6);
>  
>  	clk_disable_unprepare(imx_phy->alt_clk);
>  	clk_disable_unprepare(imx_phy->clk);
> -- 
> 2.34.1

-- 
~Vinod

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