> -----Original Message-----
> From: Krishna Chaitanya Chundru <krishna.chundru@xxxxxxxxxxxxxxxx>
> Sent: Friday, May 9, 2025 3:59 PM
> To: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Cc: linux-arm-msm@xxxxxxxxxxxxxxx; Konrad Dybcio
> <konradybcio@xxxxxxxxxx>; devicetree@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx;
> quic_vbadigan@xxxxxxxxxxx; quic_mrana@xxxxxxxxxxx; cros-qcom-dts-
> watchers@xxxxxxxxxxxx; Conor Dooley <conor+dt@xxxxxxxxxx>; Rob Herring
> <robh@xxxxxxxxxx>; Krzysztof Kozlowski <krzk+dt@xxxxxxxxxx>; Bjorn
> Andersson <andersson@xxxxxxxxxx>
> Subject: Re: [PATCH v2 2/2] PCI: Add support for PCIe wake interrupt
>
> A Gentle remainder.
>
> - Krishna Chaitanya.
>
> On 4/19/2025 11:13 AM, Krishna Chaitanya Chundru wrote:
> > PCIe wake interrupt is needed for bringing back PCIe device state from
> > D3cold to D0.
> >
> > Implement new functions, of_pci_setup_wake_irq() and
> > of_pci_teardown_wake_irq(), to manage wake interrupts for PCI devices
> > using the Device Tree.
> >
> > From the port bus driver call these functions to enable wake support
> > for bridges.
> >
> > Signed-off-by: Krishna Chaitanya Chundru
> > <krishna.chundru@xxxxxxxxxxxxxxxx>
Hi Krishna,
I have tested the patch set on i.MX platforms, it works.
you can add my Tested-by: Sherry Sun <sherry.sun@xxxxxxx>.
BTW, as PEWAKE is a standard feature in PCIe bus specification,
Suppose you may need to add wake-gpios property into the common
PCI root port dt-schema.
Best Regards
Sherry
> > ---
> > drivers/pci/of.c | 60
> ++++++++++++++++++++++++++++++++++++++++++++++
> > drivers/pci/pci.h | 6 +++++
> > drivers/pci/pcie/portdrv.c | 12 +++++++++-
> > 3 files changed, 77 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/pci/of.c b/drivers/pci/of.c index
> >
> ab7a8252bf4137a17971c3eb8ab70ce78ca70969..13623797c88a03dfb9d90795
> 18d8
> > 7a5e1e68df38 100644
> > --- a/drivers/pci/of.c
> > +++ b/drivers/pci/of.c
> > @@ -7,6 +7,7 @@
> > #define pr_fmt(fmt) "PCI: OF: " fmt
> >
> > #include <linux/cleanup.h>
> > +#include <linux/gpio/consumer.h>
> > #include <linux/irqdomain.h>
> > #include <linux/kernel.h>
> > #include <linux/pci.h>
> > @@ -15,6 +16,7 @@
> > #include <linux/of_address.h>
> > #include <linux/of_pci.h>
> > #include <linux/platform_device.h>
> > +#include <linux/pm_wakeirq.h>
> > #include "pci.h"
> >
> > #ifdef CONFIG_PCI
> > @@ -966,3 +968,61 @@ u32 of_pci_get_slot_power_limit(struct
> device_node *node,
> > return slot_power_limit_mw;
> > }
> > EXPORT_SYMBOL_GPL(of_pci_get_slot_power_limit);
> > +
> > +/**
> > + * of_pci_setup_wake_irq - Set up wake interrupt for PCI device
> > + * @pdev: The PCI device structure
> > + *
> > + * This function sets up the wake interrupt for a PCI device by
> > +getting the
> > + * corresponding GPIO pin from the device tree, and configuring it as
> > +a
> > + * dedicated wake interrupt.
> > + *
> > + * Return: 0 if the wake gpio is not available or successfully parsed
> > +else
> > + * errno otherwise.
> > + */
> > +int of_pci_setup_wake_irq(struct pci_dev *pdev) {
> > + struct gpio_desc *wake;
> > + struct device_node *dn;
> > + int ret, wake_irq;
> > +
> > + dn = pci_device_to_OF_node(pdev);
> > + if (!dn)
> > + return 0;
> > +
> > + wake = devm_fwnode_gpiod_get(&pdev->dev,
> of_fwnode_handle(dn),
> > + "wake", GPIOD_IN, NULL);
> > + if (IS_ERR(wake)) {
> > + dev_warn(&pdev->dev, "Cannot get wake GPIO\n");
> > + return 0;
> > + }
> > +
> > + wake_irq = gpiod_to_irq(wake);
> > + device_init_wakeup(&pdev->dev, true);
> > +
> > + ret = dev_pm_set_dedicated_wake_irq(&pdev->dev, wake_irq);
> > + if (ret < 0) {
> > + dev_err(&pdev->dev, "Failed to set wake IRQ: %d\n", ret);
> > + device_init_wakeup(&pdev->dev, false);
> > + return ret;
> > + }
> > + irq_set_irq_type(wake_irq, IRQ_TYPE_EDGE_FALLING);
> > +
> > + return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(of_pci_setup_wake_irq);
> > +
> > +/**
> > + * of_pci_teardown_wake_irq - Teardown wake interrupt setup for PCI
> > +device
> > + *
> > + * @pdev: The PCI device structure
> > + *
> > + * This function tears down the wake interrupt setup for a PCI
> > +device,
> > + * clearing the dedicated wake interrupt and disabling device wake-up.
> > + */
> > +void of_pci_teardown_wake_irq(struct pci_dev *pdev) {
> > + dev_pm_clear_wake_irq(&pdev->dev);
> > + device_init_wakeup(&pdev->dev, false); }
> > +EXPORT_SYMBOL_GPL(of_pci_teardown_wake_irq);
> > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index
> >
> b81e99cd4b62a3022c8b07a09f212f6888674487..b2f65289f4156fa1851c2d2f2
> 0c4
> > ca948f36258f 100644
> > --- a/drivers/pci/pci.h
> > +++ b/drivers/pci/pci.h
> > @@ -888,6 +888,9 @@ void pci_release_of_node(struct pci_dev *dev);
> > void pci_set_bus_of_node(struct pci_bus *bus);
> > void pci_release_bus_of_node(struct pci_bus *bus);
> >
> > +int of_pci_setup_wake_irq(struct pci_dev *pdev); void
> > +of_pci_teardown_wake_irq(struct pci_dev *pdev);
> > +
> > int devm_of_pci_bridge_init(struct device *dev, struct pci_host_bridge
> *bridge);
> > bool of_pci_supply_present(struct device_node *np);
> >
> > @@ -931,6 +934,9 @@ static inline int devm_of_pci_bridge_init(struct
> device *dev, struct pci_host_br
> > return 0;
> > }
> >
> > +static int of_pci_setup_wake_irq(struct pci_dev *pdev) { return 0; }
> > +static void of_pci_teardown_wake_irq(struct pci_dev *pdev) { }
> > +
> > static inline bool of_pci_supply_present(struct device_node *np)
> > {
> > return false;
> > diff --git a/drivers/pci/pcie/portdrv.c b/drivers/pci/pcie/portdrv.c
> > index
> >
> e8318fd5f6ed537a1b236a3a0f054161d5710abd..33220ecf821c348d49782855
> eb5a
> > a3f2fe5c335e 100644
> > --- a/drivers/pci/pcie/portdrv.c
> > +++ b/drivers/pci/pcie/portdrv.c
> > @@ -694,12 +694,18 @@ static int pcie_portdrv_probe(struct pci_dev *dev,
> > (type != PCI_EXP_TYPE_RC_EC)))
> > return -ENODEV;
> >
> > + status = of_pci_setup_wake_irq(dev);
> > + if (status)
> > + return status;
> > +
> > if (type == PCI_EXP_TYPE_RC_EC)
> > pcie_link_rcec(dev);
> >
> > status = pcie_port_device_register(dev);
> > - if (status)
> > + if (status) {
> > + of_pci_teardown_wake_irq(dev);
> > return status;
> > + }
> >
> > pci_save_state(dev);
> >
> > @@ -732,6 +738,8 @@ static void pcie_portdrv_remove(struct pci_dev
> > *dev)
> >
> > pcie_port_device_remove(dev);
> >
> > + of_pci_teardown_wake_irq(dev);
> > +
> > pci_disable_device(dev);
> > }
> >
> > @@ -744,6 +752,8 @@ static void pcie_portdrv_shutdown(struct pci_dev
> *dev)
> > }
> >
> > pcie_port_device_remove(dev);
> > +
> > + of_pci_teardown_wake_irq(dev);
> > }
> >
> > static pci_ers_result_t pcie_portdrv_error_detected(struct pci_dev
> > *dev,
> >
