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

[jeffy <jeffy.chen@rock-chips.com>]

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@rock-chips.com>
>> ---
>>
>>   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)
>>   };
>>
>
>
>