Date: Thu, 20 Apr 2017 16:50:46 +0800
From: Peter Chen <peter.chen@nxp.com>
To: Peter Senna Tschudin <peter.senna@collabora.com>
CC: Stephen Boyd <sboyd@codeaurora.org>,
        Fabien Lahoudere <fabien.lahoudere@collabora.co.uk>,
        Felipe Balbi <balbi@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "open list:USB PHY LAYER" <linux-usb@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>
Subject: Re: [RFC] usb-phy-generic: Add support to SMSC USB3315
Message-ID: <20170420085046.GA11378@b29397-desktop>
References: <20170419061413.20961-1-peter.senna@collabora.com>
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On Wed, Apr 19, 2017 at 06:14:13AM +0000, Peter Senna Tschudin wrote:
> We need the SMSC USB3315 clock and regulator to always be initialized.
> We also need the PHY driver to take the PHY out of reset. This patch
> extends the existing USB generic nop phy driver to include a new
> initialization path.
> 
> A new compatible string "smsc,usb3315" is used to decide which
> initialization path to use.
> 

Hi Peter,

This is an ULPI PHY, so it is not suitable using generic USB PHY.
Taking a look of drivers/phy/phy-qcom-usb-hs.c, you may have some
clues.

Peter

> CC: Peter Chen <peter.chen@nxp.com>
> CC: Stephen Boyd <sboyd@codeaurora.org>
> CC: Fabien Lahoudere <fabien.lahoudere@collabora.co.uk>
> Signed-off-by: Peter Senna Tschudin <peter.senna@collabora.com>
> ---
> 
> This is a follow-up of previous discussion:
>   https://www.spinics.net/lists/linux-usb/msg146680.html
> 
>  drivers/usb/phy/phy-generic.c | 33 +++++++++++++++++++++++++++++----
>  drivers/usb/phy/phy-generic.h |  1 +
>  2 files changed, 30 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/usb/phy/phy-generic.c b/drivers/usb/phy/phy-generic.c
> index 89d6e7a..6ea9ce4 100644
> --- a/drivers/usb/phy/phy-generic.c
> +++ b/drivers/usb/phy/phy-generic.c
> @@ -151,6 +151,9 @@ int usb_gen_phy_init(struct usb_phy *phy)
>  	struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
>  	int ret;
>  
> +	if (nop->init_done)
> +		return 0;
> +
>  	if (!IS_ERR(nop->vcc)) {
>  		if (regulator_enable(nop->vcc))
>  			dev_err(phy->dev, "Failed to enable power\n");
> @@ -164,6 +167,8 @@ int usb_gen_phy_init(struct usb_phy *phy)
>  
>  	nop_reset(nop);
>  
> +	nop->init_done = true;
> +
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(usb_gen_phy_init);
> @@ -216,18 +221,29 @@ static int nop_set_host(struct usb_otg *otg, struct usb_bus *host)
>  	otg->host = host;
>  	return 0;
>  }
> +int smsc_usb3315_init(struct usb_phy_generic *nop)
> +{
> +	/*
> +	 * If the gpio for controlling reset state is not available, try again
> +	 * later
> +	 */
> +	if(!nop->gpiod_reset)
> +		return -EPROBE_DEFER;
> +
> +	return usb_gen_phy_init(&nop->phy);
> +}
>  
>  int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop,
>  		struct usb_phy_generic_platform_data *pdata)
>  {
> +	struct device_node *node = NULL;
>  	enum usb_phy_type type = USB_PHY_TYPE_USB2;
>  	int err = 0;
> -
>  	u32 clk_rate = 0;
>  	bool needs_vcc = false;
>  
>  	if (dev->of_node) {
> -		struct device_node *node = dev->of_node;
> +		node = dev->of_node;
>  
>  		if (of_property_read_u32(node, "clock-frequency", &clk_rate))
>  			clk_rate = 0;
> @@ -304,6 +320,12 @@ int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop,
>  	nop->phy.otg->set_host		= nop_set_host;
>  	nop->phy.otg->set_peripheral	= nop_set_peripheral;
>  
> +	if(node && of_device_is_compatible(node, "smsc,usb3315")) {
> +		err = smsc_usb3315_init(nop);
> +		if (err)
> +			return err;
> +	}
> +
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy);
> @@ -318,6 +340,10 @@ static int usb_phy_generic_probe(struct platform_device *pdev)
>  	if (!nop)
>  		return -ENOMEM;
>  
> +	platform_set_drvdata(pdev, nop);
> +
> +	nop->init_done = false;
> +
>  	err = usb_phy_gen_create_phy(dev, nop, dev_get_platdata(&pdev->dev));
>  	if (err)
>  		return err;
> @@ -346,8 +372,6 @@ static int usb_phy_generic_probe(struct platform_device *pdev)
>  		return err;
>  	}
>  
> -	platform_set_drvdata(pdev, nop);
> -
>  	return 0;
>  }
>  
> @@ -362,6 +386,7 @@ static int usb_phy_generic_remove(struct platform_device *pdev)
>  
>  static const struct of_device_id nop_xceiv_dt_ids[] = {
>  	{ .compatible = "usb-nop-xceiv" },
> +	{ .compatible = "smsc,usb3315" },
>  	{ }
>  };
>  
> diff --git a/drivers/usb/phy/phy-generic.h b/drivers/usb/phy/phy-generic.h
> index 0d0eadd..db4ade6 100644
> --- a/drivers/usb/phy/phy-generic.h
> +++ b/drivers/usb/phy/phy-generic.h
> @@ -14,6 +14,7 @@ struct usb_phy_generic {
>  	struct gpio_desc *gpiod_vbus;
>  	struct regulator *vbus_draw;
>  	bool vbus_draw_enabled;
> +	bool init_done;
>  	unsigned long mA;
>  	unsigned int vbus;
>  };
> -- 
> 2.9.3
> 

-- 

Best Regards,
Peter Chen