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

[Grant Likely]

On Tue, Sep 07, 2010 at 05:54:41PM -0700, Kevin Hilman wrote:
> From: Kevin Hilman <khilman at 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 at ti.com>.
> 
> Cc: Rajendra Nayak <rnayak at ti.com>
> Signed-off-by: Kevin Hilman <khilman at 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:

Acked-by: Grant Likely <grant.likely at secretlab.ca>

I think this should go via Greg's tree to avoid ordering issues.

> ---
> 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
>