Re: [RFC PATCH 1/3] PCI: rockchip: Add support for pcie wake irq

[jeffy]

hi shawn,


On 08/16/2017 05:00 PM, Shawn Lin wrote:
> Hi Jeffy,
>
> On 2017/8/16 15:52, Jeffy Chen wrote:
> > Add support for PCIE_WAKE pin in rockchip pcie driver.
> >
> > Signed-off-by: Jeffy Chen <jeffy.chen@xxxxxxxxxxxxxx>
> > ---
> >
> >   drivers/pci/host/pcie-rockchip.c | 58
> > ++++++++++++++++++++++++++++++++++++++++
> >   1 file changed, 58 insertions(+)
> >
> > diff --git a/drivers/pci/host/pcie-rockchip.c
> > b/drivers/pci/host/pcie-rockchip.c
> > index 7bb9870f6d8c..f969a6d3cd85 100644
> > --- a/drivers/pci/host/pcie-rockchip.c
> > +++ b/drivers/pci/host/pcie-rockchip.c
> > @@ -38,6 +38,7 @@
> >   #include <linux/platform_device.h>
> >   #include <linux/reset.h>
> >   #include <linux/regmap.h>
> > +#include <linux/suspend.h>
> >   /*
> >    * The upper 16 bits of PCIE_CLIENT_CONFIG are a write mask for the
> > lower 16
> > @@ -226,6 +227,8 @@ struct rockchip_pcie {
> >       struct    regulator *vpcie1v8; /* 1.8V power supply */
> >       struct    regulator *vpcie0v9; /* 0.9V power supply */
> >       struct    gpio_desc *ep_gpio;
> > +    int    wake_irq;
> > +    bool    wake_by_pcie;
> >       u32    lanes;
> >       u8    root_bus_nr;
> >       int    link_gen;
> > @@ -853,6 +856,20 @@ static void
> > rockchip_pcie_legacy_int_handler(struct irq_desc *desc)
> >       chained_irq_exit(chip, desc);
> >   }
> > +static irqreturn_t rockchip_pcie_wake_irq_handler(int irq, void *arg)
> > +{
> > +    struct rockchip_pcie *rockchip = arg;
> > +
> > +    rockchip->wake_by_pcie = true;
> > +
> > +    disable_irq_nosync(rockchip->wake_irq);
> > +    disable_irq_wake(rockchip->wake_irq);
> > +
> > +    pm_wakeup_event(rockchip->dev, 0);
> > +    pm_system_wakeup();
> > +
> > +    return IRQ_HANDLED;
> > +}
> >   /**
> >    * rockchip_pcie_parse_dt - Parse Device Tree
> > @@ -868,6 +885,7 @@ static int rockchip_pcie_parse_dt(struct
> > rockchip_pcie *rockchip)
> >       struct resource *regs;
> >       int irq;
> >       int err;
> > +    bool wakeup = 0;
> >       regs = platform_get_resource_byname(pdev,
> >                           IORESOURCE_MEM,
> > @@ -1018,6 +1036,21 @@ static int rockchip_pcie_parse_dt(struct
> > rockchip_pcie *rockchip)
> >           return err;
> >       }
> > +    rockchip->wake_irq = platform_get_irq_byname(pdev, "wake");
> > +    if (rockchip->wake_irq >= 0) {
> > +        err = devm_request_irq(dev, rockchip->wake_irq,
> > +                       rockchip_pcie_wake_irq_handler,
> > +                       0, "pcie-wake", rockchip);
> > +        if (err) {
> > +            dev_err(dev, "failed to request PCIe wake IRQ\n");
> > +            return err;
>
> This is optional, so I'm not sure if we should prevent the driver to
> probe?
it would only break probe when there's a wake irq, but failed to enable 
it. but the wake irq itself is optional
> > +        }
> > +
> > +        disable_irq(rockchip->wake_irq);
> > +        wakeup = device_property_read_bool(dev, "wakeup-source");
>
> The purpose we add this, is for ep to wakeup the system, so why not
> always treate it as a wakeup source.
it's an extra option to disable wake by wakeup-source property
> > +    }
> > +    device_init_wakeup(dev, wakeup);
> > +
> >       rockchip->vpcie3v3 = devm_regulator_get_optional(dev, "vpcie3v3");
> >       if (IS_ERR(rockchip->vpcie3v3)) {
> >           if (PTR_ERR(rockchip->vpcie3v3) == -EPROBE_DEFER)
> > @@ -1270,6 +1303,30 @@ static int rockchip_pcie_wait_l2(struct
> > rockchip_pcie *rockchip)
> >       return 0;
> >   }
> > +static int __maybe_unused rockchip_pcie_suspend(struct device *dev)
> > +{
> > +    struct rockchip_pcie *rockchip = dev_get_drvdata(dev);
> > +
> > +    rockchip->wake_by_pcie = false;
> > +
> > +    if (device_may_wakeup(dev)) {
> > +        enable_irq_wake(rockchip->wake_irq);
> > +        enable_irq(rockchip->wake_irq);
> > +    }
> > +    return 0;
> > +}
> > +
> > +static int __maybe_unused rockchip_pcie_resume(struct device *dev)
> > +{
> > +    struct rockchip_pcie *rockchip = dev_get_drvdata(dev);
> > +
> > +    if (device_may_wakeup(dev) && !rockchip->wake_by_pcie) {
>
> I don't get this that why we need to check wake_by_pcie here?
it's to avoid double disable when it got a irq before resume
> > +        disable_irq(rockchip->wake_irq);
> > +        disable_irq_wake(rockchip->wake_irq);
> > +    }
> > +    return 0;
> > +}
> > +
> >   static int __maybe_unused rockchip_pcie_suspend_noirq(struct device
> > *dev)
> >   {
> >       struct rockchip_pcie *rockchip = dev_get_drvdata(dev);
> > @@ -1548,6 +1605,7 @@ static int rockchip_pcie_remove(struct
> > platform_device *pdev)
> >   }
> >   static const struct dev_pm_ops rockchip_pcie_pm_ops = {
> > +    SET_SYSTEM_SLEEP_PM_OPS(rockchip_pcie_suspend, rockchip_pcie_resume)
> >       SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(rockchip_pcie_suspend_noirq,
> >                         rockchip_pcie_resume_noirq)
> >   };