Re: [PATCH] arm/ls1021a: Add Sleep feature for ls1021

[Mark Rutland <mark.rutland@arm.com>]

On Fri, Sep 11, 2015 at 04:53:04AM +0100, Wang Dongsheng wrote:
> Hi Mark,

Hi,

> > > > diff --git a/arch/arm/mach-imx/pm-ls1.c b/arch/arm/mach-imx/pm-ls1.c
> > > > new file mode 100644 index 0000000..f80b24d
> > > > --- /dev/null
> > > > +++ b/arch/arm/mach-imx/pm-ls1.c
> > > > @@ -0,0 +1,222 @@
> > > > +/*
> > > > + * Support Power Management Control for LS1
> > > > + *
> > > > + * Copyright 2015 Freescale Semiconductor Inc.
> > > > + *
> > > > + * This program is free software; you can redistribute	it and/or modify it
> > > > + * under  the terms of	the GNU General	 Public License as
> > published by
> > > the
> > > > + * Free Software Foundation;  either version 2 of the  License, or
> > > > +(at your
> > > > + * option) any later version.
> > > > + */
> > > > +
> > > > +#include <linux/io.h>
> > > > +#include <linux/kernel.h>
> > > > +#include <linux/of_platform.h>
> > > > +#include <linux/of_address.h>
> > > > +#include <linux/psci.h>
> > > > +#include <linux/suspend.h>
> > > > +
> > > > +#include <uapi/linux/psci.h>
> > > > +
> > > > +#include <asm/cacheflush.h>
> > > > +#include <asm/psci.h>
> > >
> > > NAK.
> > >
> > > No new platform code should be calling the PSCI functions directly;
> > > you should not need to include these files in platform code.
> > 
> > PSCI 1.0 define SYSTEM_SUSPEND, and 0.2 and 0.1 not support this feature.
> > 
> > I will drop psci-cpu_suspend to implement SYSTEM SUSPEND, and implement system
> > suspend in platform code.
> 
> Now 0.1 and 0.2 not support SYSTEM SUSPEND, means if do system suspend we still
> need to use platform_suspend_ops to implement system suspend in platform code and
> cannot use PSCI interface to do it?

As PSCI_SYSTEM_SUSPEND was introduced in PSCI 1.0, you would need a PSCI
1.0 implementation in order to use PSCI_SYSTEM_SUSPEND. Is there
anything preventing implementing PSCI 1.0?

> How about PSCI 1.0 support, could you share some information about it?

Lorenzo has implemented basic PSCI 1.0 support [1,2], and Sudeep has
been working on SYSTEM_SUSPEND [3], though I'm not immediately aware of
the state of the world there.

Do you have any specific questions?

Thanks,
Mark.

[1] http://lists.infradead.org/pipermail/linux-arm-kernel/2015-July/355098.html
[2] http://lists.infradead.org/pipermail/linux-arm-kernel/2015-September/369806.html
[3] http://lists.infradead.org/pipermail/linux-arm-kernel/2015-September/369804.html