From akpm@linux-foundation.org Thu Apr 26 00:14:08 2007 From: David Brownell Date: Thu, 26 Apr 2007 00:12:06 -0700 Subject: define platform wakeup hook, use in pci_enable_wake() To: greg@kroah.com Cc: akpm@linux-foundation.org, david-b@pacbell.net, dbrownell@users.sourceforge.net, lenb@kernel.org, rui.zhang@intel.com Message-ID: <200704260712.l3Q7C6Ak023443@shell0.pdx.osdl.net> From: David Brownell 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#.) [akpm@linux-foundation.org: Make it compile with CONFIG_PM=n] Signed-off-by: David Brownell Signed-off-by: Zhang Rui Cc: Len Brown Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- drivers/base/power/main.c | 3 ++ drivers/pci/pci.c | 60 ++++++++++++++++++++++++++++++++-------------- include/linux/pm.h | 19 ++++++++++++++ 3 files changed, 64 insertions(+), 18 deletions(-) --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -29,6 +29,9 @@ LIST_HEAD(dpm_off_irq); DECLARE_MUTEX(dpm_sem); DECLARE_MUTEX(dpm_list_sem); +int (*platform_enable_wakeup)(struct device *dev, int is_on); + + /** * device_pm_set_parent - Specify power dependency. * @dev: Device who needs power. --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include #include @@ -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. - * - * -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. - * + * 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 + * + * 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# */ pci_read_config_word(dev,pm+PCI_PM_PMC,&value); @@ -924,8 +942,14 @@ int pci_enable_wake(struct pci_dev *dev, 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, value &= ~PCI_PM_CTRL_PME_ENABLE; pci_write_config_word(dev, pm + PCI_PM_CTRL, value); - + return 0; } --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -273,6 +273,20 @@ extern void __suspend_report_result(cons __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(st #define suspend_report_result(fn, ret) do { } while (0) +static inline int call_platform_enable_wakeup(struct device *dev, int is_on) +{ + return -EIO; +} + #endif /* changes to device_may_wakeup take effect on the next pm state change.