Messages in this thread Patch in this message | | | From | Kevin Hilman <> | Subject | Re: [PATCH v2] driver core: platform_bus: allow runtime override of dev_pm_ops | Date | Wed, 25 Aug 2010 12:50:00 -0700 |
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Grant Likely <grant.likely@secretlab.ca> writes:
> On Mon, Aug 23, 2010 at 11:18 AM, Kevin Hilman > <khilman@deeprootsystems.com> wrote: >> 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: Grant Likely <grant.likely@secretlab.ca> >> Cc: Magnus Damm <magnus.damm@gmail.com> >> Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com> > > Looks good to me. A handful of nitpicks below, I don't know if Greg > will want you to respin for these or not. Feel free to add my > acked-by line though: > > Acked-by: Grant Likely <grant.likely@secretlab.ca>
Thanks, here's a re-spin with your signoff and fixing the issues you raised.
Applies to v2.6.36-rc1.
Kevin
From 728f0ae551e805a10c9a45bcfb29f81ad45842da Mon Sep 17 00:00:00 2001 From: Kevin Hilman <khilman@ti.com> Date: Fri, 20 Aug 2010 10:46:53 -0700 Subject: [PATCH] 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> --- drivers/base/platform.c | 35 +++++++++++++++++++++++++++++++++++ include/linux/platform_device.h | 3 +++ 2 files changed, 38 insertions(+), 0 deletions(-)
diff --git a/drivers/base/platform.c b/drivers/base/platform.c index c6c933f..468bbfd 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; diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h index d7ecad0..2e700ec 100644 --- a/include/linux/platform_device.h +++ b/include/linux/platform_device.h @@ -138,6 +138,9 @@ extern struct platform_device *platform_create_bundle(struct platform_driver *dr struct resource *res, unsigned int n_res, const void *data, size_t size); +extern const struct dev_pm_ops * platform_bus_get_pm_ops(void); +extern void platform_bus_set_pm_ops(const struct dev_pm_ops *pm); + /* early platform driver interface */ struct early_platform_driver { const char *class_str; -- 1.7.2.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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