linux-kernel - Re: [PATCH v5 2/2] phy: rockchip-inno-usb2: add a new driver for Rockchip usb2phy

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Message-ID: <57601A1D.9020803@roeck-us.net>
Date:	Tue, 14 Jun 2016 07:52:13 -0700
From:	Guenter Roeck <linux@...ck-us.net>
To:	Frank Wang <frank.wang@...k-chips.com>, heiko@...ech.de,
	dianders@...omium.org, groeck@...omium.org, jwerner@...omium.org,
	kishon@...com, robh+dt@...nel.org, pawel.moll@....com,
	mark.rutland@....com, ijc+devicetree@...lion.org.uk,
	galak@...eaurora.org
Cc:	linux-kernel@...r.kernel.org, devicetree@...r.kernel.org,
	linux-usb@...r.kernel.org, linux-rockchip@...ts.infradead.org,
	xzy.xu@...k-chips.com, kever.yang@...k-chips.com,
	huangtao@...k-chips.com, william.wu@...k-chips.com
Subject: Re: [PATCH v5 2/2] phy: rockchip-inno-usb2: add a new driver for
 Rockchip usb2phy

On 06/12/2016 07:10 PM, Frank Wang wrote:
> The newer SoCs (rk3366, rk3399) take a different usb-phy IP block
> than rk3288 and before, and most of phy-related registers are also
> different from the past, so a new phy driver is required necessarily.
>
> Signed-off-by: Frank Wang <frank.wang@...k-chips.com>
> ---
>

[ ... ]

> +
> +static int rockchip_usb2phy_resume(struct phy *phy)
> +{
> +	struct rockchip_usb2phy_port *rport = phy_get_drvdata(phy);
> +	struct rockchip_usb2phy *rphy = dev_get_drvdata(phy->dev.parent);
> +	int ret;
> +
> +	dev_dbg(&rport->phy->dev, "port resume\n");
> +
> +	ret = clk_prepare_enable(rphy->clk480m);
> +	if (ret)
> +		return ret;
> +
> +	ret = property_enable(rphy, &rport->port_cfg->phy_sus, false);
> +	if (ret)
> +		return ret;
> +
> +	rport->suspended = false;
> +	return 0;
> +}
> +
> +static int rockchip_usb2phy_suspend(struct phy *phy)
> +{
> +	struct rockchip_usb2phy_port *rport = phy_get_drvdata(phy);
> +	struct rockchip_usb2phy *rphy = dev_get_drvdata(phy->dev.parent);
> +	int ret;
> +
> +	dev_dbg(&rport->phy->dev, "port suspend\n");
> +
> +	ret = property_enable(rphy, &rport->port_cfg->phy_sus, true);
> +	if (ret)
> +		return ret;
> +
> +	rport->suspended = true;
> +	clk_disable_unprepare(rphy->clk480m);
> +	return 0;
> +}
> +

I am still quite confused by the clock handling.

The above will be called for each instantiated phy (user, otg).
Each time, clk_disable_unprepare() will be called. Yet, there
is no matching clk_prepare_enable() call during initialization.

How does this work ?

Thanks,
Guenter