Re: [PATCH 2/2] phy: phy-mtk-tphy: introduce force_vbus for u2 phy

From: Chunfeng Yun <chunfeng.yun@mediatek.com>
To: Macpaul Lin <macpaul.lin@mediatek.com>
Cc: devicetree@vger.kernel.org,
	Mediatek WSD Upstream <wsd_upstream@mediatek.com>,
	linux-kernel@vger.kernel.org,
	Kishon Vijay Abraham I <kishon@ti.com>,
	Rob Herring <robh+dt@kernel.org>,
	linux-mediatek@lists.infradead.org,
	Min Guo <min.Guo@mediatek.com>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	Macpaul Lin <macpaul.lin@gmail.com>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 2/2] phy: phy-mtk-tphy: introduce force_vbus for u2 phy
Date: Fri, 17 Apr 2020 13:34:21 +0800	[thread overview]
Message-ID: <1587101661.28772.40.camel@mhfsdcap03> (raw)
In-Reply-To: <1587100986-3104-2-git-send-email-macpaul.lin@mediatek.com>

Hi Macpaul,

On Fri, 2020-04-17 at 13:23 +0800, Macpaul Lin wrote:
> For some platforms, they don't have vbus pin connection between usb phy and
> mac. Hence we need to control force_vbus related registers to keep hardware
> works normal.
> This patch add corresponding behavior of force vbus in u2 phy related
> functions.
> 
> Signed-off-by: Macpaul Lin <macpaul.lin@mediatek.com>
NACK, I tried to support it early, but found this will cause some issue
for SS/SSP device only mode, so please abandon this patch, thanks

> ---
>  drivers/phy/mediatek/phy-mtk-tphy.c | 16 +++++++++++++++-
>  1 file changed, 15 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/phy/mediatek/phy-mtk-tphy.c b/drivers/phy/mediatek/phy-mtk-tphy.c
> index cdbcc49f7115..46f0fea175e5 100644
> --- a/drivers/phy/mediatek/phy-mtk-tphy.c
> +++ b/drivers/phy/mediatek/phy-mtk-tphy.c
> @@ -99,6 +99,7 @@
>  
>  #define U3P_U2PHYDTM1		0x06C
>  #define P2C_RG_UART_EN			BIT(16)
> +#define P2C_FORCE_VBUSVALID		BIT(13)
>  #define P2C_FORCE_IDDIG		BIT(9)
>  #define P2C_RG_VBUSVALID		BIT(5)
>  #define P2C_RG_SESSEND			BIT(4)
> @@ -318,6 +319,7 @@ struct mtk_tphy {
>  	int nphys;
>  	int src_ref_clk; /* MHZ, reference clock for slew rate calibrate */
>  	int src_coef; /* coefficient for slew rate calibrate */
> +	bool force_vbus;
>  };
>  
>  static void hs_slew_rate_calibrate(struct mtk_tphy *tphy,
> @@ -611,13 +613,20 @@ static void u2_phy_instance_set_mode(struct mtk_tphy *tphy,
>  	switch (mode) {
>  	case PHY_MODE_USB_DEVICE:
>  		tmp |= P2C_FORCE_IDDIG | P2C_RG_IDDIG;
> +		if (tphy->force_vbus)
> +			tmp |= P2C_RG_VBUSVALID | P2C_FORCE_VBUSVALID;
>  		break;
>  	case PHY_MODE_USB_HOST:
>  		tmp |= P2C_FORCE_IDDIG;
> -		tmp &= ~P2C_RG_IDDIG;
> +		if (tphy->force_vbus)
> +			tmp &= ~(P2C_RG_VBUSVALID | P2C_FORCE_VBUSVALID);
> +		else
> +			tmp &= ~P2C_RG_IDDIG;
>  		break;
>  	case PHY_MODE_USB_OTG:
>  		tmp &= ~(P2C_FORCE_IDDIG | P2C_RG_IDDIG);
> +		if (tphy->force_vbus)
> +			tmp &= ~(P2C_RG_VBUSVALID | P2C_FORCE_VBUSVALID);
>  		break;
>  	default:
>  		return;
> @@ -1187,6 +1196,11 @@ static int mtk_tphy_probe(struct platform_device *pdev)
>  			retval = PTR_ERR(instance->da_ref_clk);
>  			goto put_child;
>  		}
> +
> +		/*
> +		 * On some platform, vbus is dis-connected between PHY and MAC.
> +		 */
> +		tphy->force_vbus = device_property_read_bool(dev, "force_vbus");
>  	}
>  
>  	provider = devm_of_phy_provider_register(dev, mtk_phy_xlate);

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