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author | Rafael J. Wysocki <rjw@sisk.pl> | 2011-10-07 23:17:02 +0200 |
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committer | Rafael J. Wysocki <rjw@sisk.pl> | 2011-10-07 23:17:02 +0200 |
commit | c28b56b1d46b1bbb1be33c8f2632a88b0de1ef68 (patch) | |
tree | a7caddb9f58c968f6e77f36d2d398ec06983509e /drivers/base/power/common.c | |
parent | d727b60659a1173eb4142a5fc521ce67c28b34e1 (diff) | |
parent | cd0ea672f58d5cfdea271c45cec0c897f2b792aa (diff) | |
download | linux-rt-c28b56b1d46b1bbb1be33c8f2632a88b0de1ef68.tar.gz |
Merge branch 'pm-domains' into pm-for-linus
* pm-domains:
PM / Domains: Split device PM domain data into base and need_restore
ARM: mach-shmobile: sh7372 sleep warning fixes
ARM: mach-shmobile: sh7372 A3SM support
ARM: mach-shmobile: sh7372 generic suspend/resume support
PM / Domains: Preliminary support for devices with power.irq_safe set
PM: Move clock-related definitions and headers to separate file
PM / Domains: Use power.sybsys_data to reduce overhead
PM: Reference counting of power.subsys_data
PM: Introduce struct pm_subsys_data
ARM / shmobile: Make A3RV be a subdomain of A4LC on SH7372
PM / Domains: Rename argument of pm_genpd_add_subdomain()
PM / Domains: Rename GPD_STATE_WAIT_PARENT to GPD_STATE_WAIT_MASTER
PM / Domains: Allow generic PM domains to have multiple masters
PM / Domains: Add "wait for parent" status for generic PM domains
PM / Domains: Make pm_genpd_poweron() always survive parent removal
PM / Domains: Do not take parent locks to modify subdomain counters
PM / Domains: Implement subdomain counters as atomic fields
Diffstat (limited to 'drivers/base/power/common.c')
-rw-r--r-- | drivers/base/power/common.c | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/drivers/base/power/common.c b/drivers/base/power/common.c new file mode 100644 index 000000000000..29820c396182 --- /dev/null +++ b/drivers/base/power/common.c @@ -0,0 +1,86 @@ +/* + * drivers/base/power/common.c - Common device power management code. + * + * Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp. + * + * This file is released under the GPLv2. + */ + +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/pm_clock.h> + +/** + * dev_pm_get_subsys_data - Create or refcount power.subsys_data for device. + * @dev: Device to handle. + * + * If power.subsys_data is NULL, point it to a new object, otherwise increment + * its reference counter. Return 1 if a new object has been created, otherwise + * return 0 or error code. + */ +int dev_pm_get_subsys_data(struct device *dev) +{ + struct pm_subsys_data *psd; + int ret = 0; + + psd = kzalloc(sizeof(*psd), GFP_KERNEL); + if (!psd) + return -ENOMEM; + + spin_lock_irq(&dev->power.lock); + + if (dev->power.subsys_data) { + dev->power.subsys_data->refcount++; + } else { + spin_lock_init(&psd->lock); + psd->refcount = 1; + dev->power.subsys_data = psd; + pm_clk_init(dev); + psd = NULL; + ret = 1; + } + + spin_unlock_irq(&dev->power.lock); + + /* kfree() verifies that its argument is nonzero. */ + kfree(psd); + + return ret; +} +EXPORT_SYMBOL_GPL(dev_pm_get_subsys_data); + +/** + * dev_pm_put_subsys_data - Drop reference to power.subsys_data. + * @dev: Device to handle. + * + * If the reference counter of power.subsys_data is zero after dropping the + * reference, power.subsys_data is removed. Return 1 if that happens or 0 + * otherwise. + */ +int dev_pm_put_subsys_data(struct device *dev) +{ + struct pm_subsys_data *psd; + int ret = 0; + + spin_lock_irq(&dev->power.lock); + + psd = dev_to_psd(dev); + if (!psd) { + ret = -EINVAL; + goto out; + } + + if (--psd->refcount == 0) { + dev->power.subsys_data = NULL; + kfree(psd); + ret = 1; + } + + out: + spin_unlock_irq(&dev->power.lock); + + return ret; +} +EXPORT_SYMBOL_GPL(dev_pm_put_subsys_data); |