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

hi shawn,


On 08/16/2017 05:00 PM, Shawn Lin wrote:

Hi Jeffy,

On 2017/8/16 15:52, Jeffy Chen wrote:

quoted

Add support for PCIE_WAKE pin in rockchip pcie driver.

Signed-off-by: Jeffy Chen <redacted>
---

  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

quoted

+        }
+
+        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

quoted

+    }
+    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

quoted

+        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)
  };