Re: [PATCH 1/2] OMAP2+: PM: initial runtime PM core support

[Kevin Hilman <khilman@deeprootsystems.com>]

Grant Likely <grant.likely@secretlab.ca> writes:

> On Tue, Sep 07, 2010 at 05:54:41PM -0700, Kevin Hilman wrote:
>> From: Kevin Hilman <khilman@ti.com>
>> 
>> Implement the new runtime PM framework as a thin layer on top of the
>> omap_device API.  OMAP specific runtime PM methods are registered with
>> the as custom methods on the platform_bus.
>> 
>> In order to determine if a device is an omap_device, its parent device
>> is checked.  All omap_devices have a new 'omap_bus' device as their
>> parent device, so checking for this parent is used to check for valid
>> omap_devices.  If a device is an omap_device, then the appropriate
>> omap_device functions are called for it.  If not, only the generic
>> runtime PM functions are called.
>> 
>> Device driver's ->runtime_idle() hook is called when the runtime PM
>> usecount reaches zero for that device.  Driver's ->runtime_suspend()
>> hooks are called just before the device is disabled (via
>> omap_device_idle()), and device driver ->runtime_resume() hooks are
>> called just after device has been enabled (via omap_device_enable().)
>> 
>> OMAP4 build support from Rajendra Nayak <rnayak@ti.com>.
>> 
>> Cc: Rajendra Nayak <rnayak@ti.com>
>> Signed-off-by: Kevin Hilman <khilman@ti.com>
>
> It appears that this one will fail to compile when CONFIG_PM_RUNTIME
> is unset.  Once you've fixed that you can add my a-b line:

Thanks for catching this. 

> Acked-by: Grant Likely <grant.likely@secretlab.ca>
>
> I think this should go via Greg's tree to avoid ordering issues.

Not a strong preference, but I'd rather see this go via OMAP as we are
building on it in the OMAP tree for this merge window.  The ordering
issues will only affect OMAP users and I have taken care of that in my
staging branches that other are using for their runtime PM conversions.

Kevin

>> ---
>> NOTE: this depends on the driver core patch from me:
>> [PATCH v2] driver core: platform_bus: allow runtime override of dev_pm_ops
>> which Greg KH has queued now for 2.6.37:
>> http://marc.info/?l=linux-kernel&m=128276582108006&w=2
>> 
>>  arch/arm/mach-omap2/Makefile |    8 +++-
>>  arch/arm/mach-omap2/pm_bus.c |   82 ++++++++++++++++++++++++++++++++++++++++++
>>  2 files changed, 88 insertions(+), 2 deletions(-)
>>  create mode 100644 arch/arm/mach-omap2/pm_bus.c
>> 
>> diff --git a/arch/arm/mach-omap2/Makefile b/arch/arm/mach-omap2/Makefile
>> index 88d3a1e..ba644c2 100644
>> --- a/arch/arm/mach-omap2/Makefile
>> +++ b/arch/arm/mach-omap2/Makefile
>> @@ -50,13 +50,17 @@ obj-$(CONFIG_ARCH_OMAP2)		+= sdrc2xxx.o
>>  ifeq ($(CONFIG_PM),y)
>>  obj-$(CONFIG_ARCH_OMAP2)		+= pm24xx.o
>>  obj-$(CONFIG_ARCH_OMAP2)		+= sleep24xx.o
>> -obj-$(CONFIG_ARCH_OMAP3)		+= pm34xx.o sleep34xx.o cpuidle34xx.o
>> -obj-$(CONFIG_ARCH_OMAP4)		+= pm44xx.o
>> +obj-$(CONFIG_ARCH_OMAP3)		+= pm34xx.o sleep34xx.o cpuidle34xx.o pm_bus.o
>> +obj-$(CONFIG_ARCH_OMAP4)		+= pm44xx.o pm_bus.o
>>  obj-$(CONFIG_PM_DEBUG)			+= pm-debug.o
>>  
>>  AFLAGS_sleep24xx.o			:=-Wa,-march=armv6
>>  AFLAGS_sleep34xx.o			:=-Wa,-march=armv7-a
>>  
>> +ifeq ($(CONFIG_PM_VERBOSE),y)
>> +CFLAGS_pm_bus.o				+= -DDEBUG
>> +endif
>> +
>>  endif
>>  
>>  # PRCM
>> diff --git a/arch/arm/mach-omap2/pm_bus.c b/arch/arm/mach-omap2/pm_bus.c
>> new file mode 100644
>> index 0000000..e85aced
>> --- /dev/null
>> +++ b/arch/arm/mach-omap2/pm_bus.c
>> @@ -0,0 +1,82 @@
>> +/*
>> + * Runtime PM support code for OMAP
>> + *
>> + * Author: Kevin Hilman, Deep Root Systems, LLC
>> + *
>> + * Copyright (C) 2010 Texas Instruments, Inc.
>> + *
>> + * This file is licensed under the terms of the GNU General Public
>> + * License version 2. This program is licensed "as is" without any
>> + * warranty of any kind, whether express or implied.
>> + */
>> +#include <linux/init.h>
>> +#include <linux/kernel.h>
>> +#include <linux/io.h>
>> +#include <linux/pm_runtime.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/mutex.h>
>> +
>> +#include <plat/omap_device.h>
>> +#include <plat/omap-pm.h>
>> +
>> +#ifdef CONFIG_PM_RUNTIME
>> +int omap_pm_runtime_suspend(struct device *dev)
>> +{
>> +	struct platform_device *pdev = to_platform_device(dev);
>> +	int r, ret = 0;
>> +
>> +	dev_dbg(dev, "%s\n", __func__);
>> +
>> +	ret = pm_generic_runtime_suspend(dev);
>> +
>> +	if (!ret && dev->parent == &omap_bus) {
>> +		r = omap_device_idle(pdev);
>> +		WARN_ON(r);
>> +	}
>> +
>> +	return ret;
>> +};
>> +
>> +int omap_pm_runtime_resume(struct device *dev)
>> +{
>> +	struct platform_device *pdev = to_platform_device(dev);
>> +	int r;
>> +
>> +	dev_dbg(dev, "%s\n", __func__);
>> +
>> +	if (dev->parent == &omap_bus) {
>> +		r = omap_device_enable(pdev);
>> +		WARN_ON(r);
>> +	}
>> +
>> +	return pm_generic_runtime_resume(dev);
>> +};
>> +#endif /* CONFIG_PM_RUNTIME */
>> +
>> +static int __init omap_pm_runtime_init(void)
>> +{
>> +	const struct dev_pm_ops *pm;
>> +	struct dev_pm_ops *omap_pm;
>> +
>> +	pm = platform_bus_get_pm_ops();
>> +	if (!pm) {
>> +		pr_err("%s: unable to get dev_pm_ops from platform_bus\n",
>> +			__func__);
>> +		return -ENODEV;
>> +	}
>> +
>> +	omap_pm = kmemdup(pm, sizeof(struct dev_pm_ops), GFP_KERNEL);
>> +	if (!omap_pm) {
>> +		pr_err("%s: unable to alloc memory for new dev_pm_ops\n",
>> +			__func__);
>> +		return -ENOMEM;
>> +	}
>> +		
>> +	omap_pm->runtime_suspend = omap_pm_runtime_suspend;
>> +	omap_pm->runtime_resume = omap_pm_runtime_resume;
>
> This will fail to build when CONFIG_PM_RUNTIME is unset.  None of this file should be build when CONFIG_PM_RUNTIME=n.
>
>> +
>> +	platform_bus_set_pm_ops(omap_pm);
>> +
>> +	return 0;
>> +}
>> +core_initcall(omap_pm_runtime_init);
>> -- 
>> 1.7.2.1
>>