linux-kernel - Re: [RFC PATCH] usb: chipidea: Add support for VBUS control with PHY

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Message-ID: <20220703003434.GA1382015@Peter>
Date:   Sun, 3 Jul 2022 08:34:34 +0800
From:   Peter Chen <peter.chen@...nel.org>
To:     Piyush Mehta <piyush.mehta@...inx.com>
Cc:     gregkh@...uxfoundation.org, michal.simek@...inx.com,
        linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org,
        git@...inx.com, sivadur@...inx.com, radheys@...inx.com
Subject: Re: [RFC PATCH] usb: chipidea: Add support for VBUS control with PHY

On 22-05-24 17:38:02, Piyush Mehta wrote:
> Some platforms make use of VBUS control over PHY which means controller
> driver has to access PHY registers to turn on/off VBUS line.This patch
> adds support for such platforms in chipidea.
> 
> Flag 'CI_HDRC_PHY_VBUS_CONTROL' added to support VBus control feature.
> 
> Signed-off-by: Piyush Mehta <piyush.mehta@...inx.com>
> ---
> We have created this patch as RFC, as I introduced a new flag
> (CI_HDRC_PHY_VBUS_CONTROL) and would like to get comment if
> it's the proper way to check for VBus support for zynq.
> ---
>  drivers/usb/chipidea/ci_hdrc_usb2.c | 1 +
>  drivers/usb/chipidea/host.c         | 7 +++++++
>  drivers/usb/chipidea/otg_fsm.c      | 7 +++++++
>  include/linux/usb/chipidea.h        | 1 +
>  4 files changed, 16 insertions(+)
> 
> diff --git a/drivers/usb/chipidea/ci_hdrc_usb2.c b/drivers/usb/chipidea/ci_hdrc_usb2.c
> index 89e1d82..dc86b12 100644
> --- a/drivers/usb/chipidea/ci_hdrc_usb2.c
> +++ b/drivers/usb/chipidea/ci_hdrc_usb2.c
> @@ -30,6 +30,7 @@ static const struct ci_hdrc_platform_data ci_default_pdata = {
>  
>  static const struct ci_hdrc_platform_data ci_zynq_pdata = {
>  	.capoffset	= DEF_CAPOFFSET,
> +	.flags          = CI_HDRC_PHY_VBUS_CONTROL,
>  };
>  
>  static const struct ci_hdrc_platform_data ci_zevio_pdata = {
> diff --git a/drivers/usb/chipidea/host.c b/drivers/usb/chipidea/host.c
> index bdc3885..bc3634a 100644
> --- a/drivers/usb/chipidea/host.c
> +++ b/drivers/usb/chipidea/host.c
> @@ -63,6 +63,13 @@ static int ehci_ci_portpower(struct usb_hcd *hcd, int portnum, bool enable)
>  		priv->enabled = enable;
>  	}
>  
> +	if (ci->platdata->flags & CI_HDRC_PHY_VBUS_CONTROL) {
> +		if (enable)
> +			usb_phy_vbus_on(ci->usb_phy);
> +		else
> +			usb_phy_vbus_off(ci->usb_phy);
> +	}
> +
>  	if (enable && (ci->platdata->phy_mode == USBPHY_INTERFACE_MODE_HSIC)) {
>  		/*
>  		 * Marvell 28nm HSIC PHY requires forcing the port to HS mode.
> diff --git a/drivers/usb/chipidea/otg_fsm.c b/drivers/usb/chipidea/otg_fsm.c
> index 6ed4b00..5ed9164 100644
> --- a/drivers/usb/chipidea/otg_fsm.c
> +++ b/drivers/usb/chipidea/otg_fsm.c
> @@ -471,6 +471,10 @@ static void ci_otg_drv_vbus(struct otg_fsm *fsm, int on)
>  				return;
>  			}
>  		}
> +
> +		if (ci->platdata->flags & CI_HDRC_PHY_VBUS_CONTROL)
> +			usb_phy_vbus_on(ci->usb_phy);
> +
>  		/* Disable data pulse irq */
>  		hw_write_otgsc(ci, OTGSC_DPIE, 0);
>  
> @@ -480,6 +484,9 @@ static void ci_otg_drv_vbus(struct otg_fsm *fsm, int on)
>  		if (ci->platdata->reg_vbus)
>  			regulator_disable(ci->platdata->reg_vbus);
>  
> +		if (ci->platdata->flags & CI_HDRC_PHY_VBUS_CONTROL)
> +			usb_phy_vbus_off(ci->usb_phy);
> +

Have your platform used OTG FSM? If not used, do not need to change it.
Otherwise, it is okay for me.

Peter

>  		fsm->a_bus_drop = 1;
>  		fsm->a_bus_req = 0;
>  	}
> diff --git a/include/linux/usb/chipidea.h b/include/linux/usb/chipidea.h
> index edf3342..ee38835 100644
> --- a/include/linux/usb/chipidea.h
> +++ b/include/linux/usb/chipidea.h
> @@ -62,6 +62,7 @@ struct ci_hdrc_platform_data {
>  #define CI_HDRC_REQUIRES_ALIGNED_DMA	BIT(13)
>  #define CI_HDRC_IMX_IS_HSIC		BIT(14)
>  #define CI_HDRC_PMQOS			BIT(15)
> +#define CI_HDRC_PHY_VBUS_CONTROL	BIT(16)
>  	enum usb_dr_mode	dr_mode;
>  #define CI_HDRC_CONTROLLER_RESET_EVENT		0
>  #define CI_HDRC_CONTROLLER_STOPPED_EVENT	1
> -- 
> 2.7.4
> 

-- 

Thanks,
Peter Chen