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authorRafael J. Wysocki <rjw@sisk.pl>2011-10-07 23:17:02 +0200
committerRafael J. Wysocki <rjw@sisk.pl>2011-10-07 23:17:02 +0200
commitc28b56b1d46b1bbb1be33c8f2632a88b0de1ef68 (patch)
treea7caddb9f58c968f6e77f36d2d398ec06983509e /drivers/base/power/common.c
parentd727b60659a1173eb4142a5fc521ce67c28b34e1 (diff)
parentcd0ea672f58d5cfdea271c45cec0c897f2b792aa (diff)
downloadlinux-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.c86
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);