Re: [PATCH v6 2/2] phy: rockchip-inno-usb2: add a new driver for Rockchip usb2phy

[Frank Wang]

Hi Guenter,

On 2016/6/17 12:59, Guenter Roeck wrote:
> On 06/16/2016 07:09 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@xxxxxxxxxxxxxx>
> > Suggested-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> > Suggested-by: Doug Anderson <dianders@xxxxxxxxxxxx>
> > Reviewed-by: Heiko Stuebner <heiko@xxxxxxxxx>
> > Tested-by: Heiko Stuebner <heiko@xxxxxxxxx>
> > ---
>
> [ ... ]
>
> > +
> > +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;
> > +
> If suspend can be called multiple times, resume can be called
> multiple times as well. Doesn't this cause a clock imbalance
> if you call clk_prepare_enable() multiple times on resume,
> but clk_disable_unprepare() only once on suspend ?

Well, what you said is reasonable, How does something like below?

@@ -307,6 +307,9 @@ static int rockchip_usb2phy_resume(struct phy *phy)

        dev_dbg(&rport->phy->dev, "port resume\n");

+       if (!rport->suspended)
+               return 0;
+
        ret = clk_prepare_enable(rphy->clk480m);
        if (ret)
                return ret;
@@ -327,12 +330,16 @@ static int rockchip_usb2phy_suspend(struct phy *phy)

        dev_dbg(&rport->phy->dev, "port suspend\n");

+       if (rport->suspended)
+               return 0;
+
        ret = property_enable(rphy, &rport->port_cfg->phy_sus, true);
        if (ret)
                return ret;

        rport->suspended = true;
        clk_disable_unprepare(rphy->clk480m);
+
        return 0;
 }

@@ -485,6 +492,7 @@ static int rockchip_usb2phy_host_port_init(struct 
rockchip_usb2phy *rphy,

        rport->port_id = USB2PHY_PORT_HOST;
        rport->port_cfg = &rphy->phy_cfg->port_cfgs[USB2PHY_PORT_HOST];
+       rport->suspended = true;

        mutex_init(&rport->mutex);
        INIT_DELAYED_WORK(&rport->sm_work, rockchip_usb2phy_sm_work);


> > +    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");
> > +
> > +    if (rport->suspended)
> > +        goto exit;
> > +
>
> I know I am nitpicking, but
>         return 0;
> would be fine here, be more consistent with the rest of the code,

Yeah, please see above changes.

BR.
Frank

> > +    ret = property_enable(rphy, &rport->port_cfg->phy_sus, true);
> > +    if (ret)
> > +        return ret;
> > +
> > +    rport->suspended = true;
> > +    clk_disable_unprepare(rphy->clk480m);
> > +
> > +exit:
> > +    return 0;
>
> and this label is really unnecessary.
>
> > +}
> > +
>
> [ ... ]