summaryrefslogtreecommitdiffstats
path: root/drivers/base/power/common.c
diff options
context:
space:
mode:
authorJiri Kosina <jkosina@suse.cz>2011-11-13 20:55:35 +0100
committerJiri Kosina <jkosina@suse.cz>2011-11-13 20:55:53 +0100
commit2290c0d06d82faee87b1ab2d9d4f7bf81ef64379 (patch)
treee075e4d5534193f28e6059904f61e5ca03958d3c /drivers/base/power/common.c
parent4da669a2e3e5bc70b30a0465f3641528681b5f77 (diff)
parent52e4c2a05256cb83cda12f3c2137ab1533344edb (diff)
Merge branch 'master' into for-next
Sync with Linus tree to have 157550ff ("mtd: add GPMI-NAND driver in the config and Makefile") as I have patch depending on that one.
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 00000000000..4af7c1cbf90
--- /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/export.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);