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

[Guenter Roeck]

Hi Frank,

On 06/16/2016 11:43 PM, Frank Wang wrote:
> 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;

Why does it start in suspended mode ? That seems odd.

Guenter

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