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989561de9b
Adds a function that sets the pointer to dev_pm_domain in struct device and that warns if the device has already finished probing. The reason why we want to enforce that is because in the general case that can cause problems and also that we can simplify code quite a bit if we can always assume that. This patch also changes all current code that directly sets the dev.pm_domain pointer. Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
151 lines
4.1 KiB
C
151 lines
4.1 KiB
C
/*
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* drivers/base/power/common.c - Common device power management code.
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*
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* Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
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*
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* This file is released under the GPLv2.
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*/
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#include <linux/kernel.h>
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#include <linux/device.h>
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#include <linux/export.h>
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#include <linux/slab.h>
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#include <linux/pm_clock.h>
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#include <linux/acpi.h>
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#include <linux/pm_domain.h>
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/**
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* dev_pm_get_subsys_data - Create or refcount power.subsys_data for device.
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* @dev: Device to handle.
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*
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* If power.subsys_data is NULL, point it to a new object, otherwise increment
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* its reference counter. Return 0 if new object has been created or refcount
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* increased, otherwise negative error code.
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*/
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int dev_pm_get_subsys_data(struct device *dev)
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{
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struct pm_subsys_data *psd;
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psd = kzalloc(sizeof(*psd), GFP_KERNEL);
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if (!psd)
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return -ENOMEM;
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spin_lock_irq(&dev->power.lock);
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if (dev->power.subsys_data) {
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dev->power.subsys_data->refcount++;
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} else {
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spin_lock_init(&psd->lock);
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psd->refcount = 1;
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dev->power.subsys_data = psd;
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pm_clk_init(dev);
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psd = NULL;
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}
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spin_unlock_irq(&dev->power.lock);
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/* kfree() verifies that its argument is nonzero. */
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kfree(psd);
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return 0;
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}
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EXPORT_SYMBOL_GPL(dev_pm_get_subsys_data);
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/**
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* dev_pm_put_subsys_data - Drop reference to power.subsys_data.
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* @dev: Device to handle.
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*
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* If the reference counter of power.subsys_data is zero after dropping the
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* reference, power.subsys_data is removed.
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*/
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void dev_pm_put_subsys_data(struct device *dev)
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{
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struct pm_subsys_data *psd;
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spin_lock_irq(&dev->power.lock);
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psd = dev_to_psd(dev);
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if (!psd)
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goto out;
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if (--psd->refcount == 0)
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dev->power.subsys_data = NULL;
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else
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psd = NULL;
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out:
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spin_unlock_irq(&dev->power.lock);
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kfree(psd);
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}
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EXPORT_SYMBOL_GPL(dev_pm_put_subsys_data);
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/**
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* dev_pm_domain_attach - Attach a device to its PM domain.
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* @dev: Device to attach.
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* @power_on: Used to indicate whether we should power on the device.
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*
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* The @dev may only be attached to a single PM domain. By iterating through
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* the available alternatives we try to find a valid PM domain for the device.
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* As attachment succeeds, the ->detach() callback in the struct dev_pm_domain
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* should be assigned by the corresponding attach function.
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*
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* This function should typically be invoked from subsystem level code during
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* the probe phase. Especially for those that holds devices which requires
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* power management through PM domains.
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*
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* Callers must ensure proper synchronization of this function with power
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* management callbacks.
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*
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* Returns 0 on successfully attached PM domain or negative error code.
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*/
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int dev_pm_domain_attach(struct device *dev, bool power_on)
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{
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int ret;
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ret = acpi_dev_pm_attach(dev, power_on);
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if (ret)
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ret = genpd_dev_pm_attach(dev);
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return ret;
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}
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EXPORT_SYMBOL_GPL(dev_pm_domain_attach);
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/**
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* dev_pm_domain_detach - Detach a device from its PM domain.
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* @dev: Device to detach.
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* @power_off: Used to indicate whether we should power off the device.
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*
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* This functions will reverse the actions from dev_pm_domain_attach() and thus
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* try to detach the @dev from its PM domain. Typically it should be invoked
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* from subsystem level code during the remove phase.
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*
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* Callers must ensure proper synchronization of this function with power
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* management callbacks.
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*/
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void dev_pm_domain_detach(struct device *dev, bool power_off)
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{
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if (dev->pm_domain && dev->pm_domain->detach)
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dev->pm_domain->detach(dev, power_off);
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}
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EXPORT_SYMBOL_GPL(dev_pm_domain_detach);
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/**
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* dev_pm_domain_set - Set PM domain of a device.
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* @dev: Device whose PM domain is to be set.
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* @pd: PM domain to be set, or NULL.
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*
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* Sets the PM domain the device belongs to. The PM domain of a device needs
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* to be set before its probe finishes (it's bound to a driver).
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*
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* This function must be called with the device lock held.
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*/
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void dev_pm_domain_set(struct device *dev, struct dev_pm_domain *pd)
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{
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if (dev->pm_domain == pd)
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return;
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WARN(device_is_bound(dev),
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"PM domains can only be changed for unbound devices\n");
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dev->pm_domain = pd;
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}
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EXPORT_SYMBOL_GPL(dev_pm_domain_set);
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