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authorKevin Hilman <khilman@ti.com>2010-08-25 23:50:00 +0400
committerGreg Kroah-Hartman <gregkh@suse.de>2010-10-22 21:16:42 +0400
commitc64a0926710153b9d44c979d2942f4a8648fd74e (patch)
tree331fe35475ec201c69c2292773a229659e07eb8b /drivers/base
parent1037246cacd45d951227c8798f181b3ba5c8bcbe (diff)
downloadlinux-c64a0926710153b9d44c979d2942f4a8648fd74e.tar.xz
driver core: platform_bus: allow runtime override of dev_pm_ops
Currently, the platform_bus allows customization of several of the busses dev_pm_ops methods by using weak symbols so that platform code can override them. The weak-symbol approach is not scalable when wanting to support multiple platforms in a single kernel binary. Instead, provide __init methods for platform code to customize the dev_pm_ops methods at runtime. NOTE: after these dynamic methods are merged, the weak symbols should be removed from drivers/base/platform.c. AFAIK, this will only affect SH and sh-mobile which should be converted to use this runtime approach instead of the weak symbols. After SH & sh-mobile are converted, the weak symobols could be removed. Tested on OMAP3. Cc: Magnus Damm <magnus.damm@gmail.com> Acked-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/base')
-rw-r--r--drivers/base/platform.c35
1 files changed, 35 insertions, 0 deletions
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 579906f88b09..a01abf9ebf7b 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -976,6 +976,41 @@ struct bus_type platform_bus_type = {
};
EXPORT_SYMBOL_GPL(platform_bus_type);
+/**
+ * platform_bus_get_pm_ops() - return pointer to busses dev_pm_ops
+ *
+ * This function can be used by platform code to get the current
+ * set of dev_pm_ops functions used by the platform_bus_type.
+ */
+const struct dev_pm_ops * __init platform_bus_get_pm_ops(void)
+{
+ return platform_bus_type.pm;
+}
+
+/**
+ * platform_bus_set_pm_ops() - update dev_pm_ops for the platform_bus_type
+ *
+ * @pm: pointer to new dev_pm_ops struct to be used for platform_bus_type
+ *
+ * Platform code can override the dev_pm_ops methods of
+ * platform_bus_type by using this function. It is expected that
+ * platform code will first do a platform_bus_get_pm_ops(), then
+ * kmemdup it, then customize selected methods and pass a pointer to
+ * the new struct dev_pm_ops to this function.
+ *
+ * Since platform-specific code is customizing methods for *all*
+ * devices (not just platform-specific devices) it is expected that
+ * any custom overrides of these functions will keep existing behavior
+ * and simply extend it. For example, any customization of the
+ * runtime PM methods should continue to call the pm_generic_*
+ * functions as the default ones do in addition to the
+ * platform-specific behavior.
+ */
+void __init platform_bus_set_pm_ops(const struct dev_pm_ops *pm)
+{
+ platform_bus_type.pm = pm;
+}
+
int __init platform_bus_init(void)
{
int error;