Commit 075c1771 authored by David Brownell's avatar David Brownell Committed by Greg Kroah-Hartman
Browse files

define platform wakeup hook, use in pci_enable_wake()

This defines a platform hook to enable/disable a device as a wakeup event
source.  It's initially for use with ACPI, but more generally it could be used
whenever enable_irq_wake()/disable_irq_wake() don't suffice.

The hook is called -- if available -- inside pci_enable_wake(); and the
semantics of that call are enhanced so that support for PCI PME# is no longer
needed.  It can now work for devices with "legacy PCI PM", when platform
support allows it.  (That support would use some board-specific signal for for
the same purpose as PME#.)

[ Make it compile with CONFIG_PM=n]
Signed-off-by: default avatarDavid Brownell <>
Signed-off-by: default avatarZhang Rui <>
Cc: Len Brown <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarGreg Kroah-Hartman <>
parent 057f6c01
......@@ -29,6 +29,9 @@ LIST_HEAD(dpm_off_irq);
int (*platform_enable_wakeup)(struct device *dev, int is_on);
* device_pm_set_parent - Specify power dependency.
* @dev: Device who needs power.
......@@ -13,6 +13,7 @@
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/pm.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/string.h>
......@@ -891,31 +892,48 @@ pci_disable_device(struct pci_dev *dev)
* pci_enable_wake - enable device to generate PME# when suspended
* @dev: - PCI device to operate on
* @state: - Current state of device.
* @enable: - Flag to enable or disable generation
* Set the bits in the device's PM Capabilities to generate PME# when
* the system is suspended.
* pci_enable_wake - enable PCI device as wakeup event source
* @dev: PCI device affected
* @state: PCI state from which device will issue wakeup events
* @enable: True to enable event generation; false to disable
* -EIO is returned if device doesn't have PM Capabilities.
* -EINVAL is returned if device supports it, but can't generate wake events.
* 0 if operation is successful.
* This enables the device as a wakeup event source, or disables it.
* When such events involves platform-specific hooks, those hooks are
* called automatically by this routine.
* Devices with legacy power management (no standard PCI PM capabilities)
* always require such platform hooks. Depending on the platform, devices
* supporting the standard PCI PME# signal may require such platform hooks;
* they always update bits in config space to allow PME# generation.
* -EIO is returned if the device can't ever be a wakeup event source.
* -EINVAL is returned if the device can't generate wakeup events from
* the specified PCI state. Returns zero if the operation is successful.
int pci_enable_wake(struct pci_dev *dev, pci_power_t state, int enable)
int pm;
int status;
u16 value;
/* Note that drivers should verify device_may_wakeup(&dev->dev)
* before calling this function. Platform code should report
* errors when drivers try to enable wakeup on devices that
* can't issue wakeups, or on which wakeups were disabled by
* userspace updating the /sys/devices.../power/wakeup file.
status = call_platform_enable_wakeup(&dev->dev, enable);
/* find PCI PM capability in list */
pm = pci_find_capability(dev, PCI_CAP_ID_PM);
/* If device doesn't support PM Capabilities, but request is to disable
* wake events, it's a nop; otherwise fail */
if (!pm)
return enable ? -EIO : 0;
/* If device doesn't support PM Capabilities, but caller wants to
* disable wake events, it's a NOP. Otherwise fail unless the
* platform hooks handled this legacy device already.
if (!pm)
return enable ? status : 0;
/* Check device's ability to generate PME# */
......@@ -924,8 +942,14 @@ int pci_enable_wake(struct pci_dev *dev, pci_power_t state, int enable)
value >>= ffs(PCI_PM_CAP_PME_MASK) - 1; /* First bit of mask */
/* Check if it can generate PME# from requested state. */
if (!value || !(value & (1 << state)))
if (!value || !(value & (1 << state))) {
/* if it can't, revert what the platform hook changed,
* always reporting the base "EINVAL, can't PME#" error
if (enable)
call_platform_enable_wakeup(&dev->dev, 0);
return enable ? -EINVAL : 0;
pci_read_config_word(dev, pm + PCI_PM_CTRL, &value);
......@@ -936,7 +960,7 @@ int pci_enable_wake(struct pci_dev *dev, pci_power_t state, int enable)
pci_write_config_word(dev, pm + PCI_PM_CTRL, value);
return 0;
......@@ -273,6 +273,20 @@ extern void __suspend_report_result(const char *function, void *fn, int ret);
__suspend_report_result(__FUNCTION__, fn, ret); \
} while (0)
* Platform hook to activate device wakeup capability, if that's not already
* handled by enable_irq_wake() etc.
* Returns zero on success, else negative errno
extern int (*platform_enable_wakeup)(struct device *dev, int is_on);
static inline int call_platform_enable_wakeup(struct device *dev, int is_on)
if (platform_enable_wakeup)
return (*platform_enable_wakeup)(dev, is_on);
return 0;
#else /* !CONFIG_PM */
static inline int device_suspend(pm_message_t state)
......@@ -294,6 +308,11 @@ static inline void dpm_runtime_resume(struct device * dev)
#define suspend_report_result(fn, ret) do { } while (0)
static inline int call_platform_enable_wakeup(struct device *dev, int is_on)
return -EIO;
/* changes to device_may_wakeup take effect on the next pm state change.
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment