Re: [PATCH v5 07/14] ARM: mvebu: Extend the pmsu registers

Thomas Petazzoni
2014-03-26T12:59:51Z

Dear Sebastian Hesselbarth,

On Wed, 26 Mar 2014 13:04:55 +0100, Sebastian Hesselbarth wrote:
> On 03/25/2014 11:48 PM, Gregory CLEMENT wrote:
> > The initial binding for PMSU were wrong. It didn't take into account
> > all the registers from the PMSU and moreover it referred to registers
> > which are not part of PMSU.
> >
> > The Power Management Unit Service block also controls the Coherency
> > Fabric subsystem. These registers are needed for the CPU idle
> > implementation for the Armada 370/XP, it allows to enter a deep CPU
> > idle state where the Coherency Fabric and the L2 cache are powered
> > down.
> >
> > This commit add support for a new compatible for the PMSU node
> > including the block related to the coherency fabric. It also keeps
> > compatibility with the old binding
> >
> > This patch also adds warnings if one of the base registers set can't
> > be ioremapped.
> >
> > Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
> > ---
> > arch/arm/mach-mvebu/pmsu.c | 47 +++++++++++++++++++++++++++++++++++++++++-----
> > 1 file changed, 42 insertions(+), 5 deletions(-)
> >
> > diff --git a/arch/arm/mach-mvebu/pmsu.c b/arch/arm/mach-mvebu/pmsu.c
> > index d71ef53107c4..865bcb651e01 100644
> > --- a/arch/arm/mach-mvebu/pmsu.c
> > +++ b/arch/arm/mach-mvebu/pmsu.c
> [...]
> > +static void __init armada_370_xp_pmsu_legacy_init(struct device_node *np)
> > +{
> > + u32 addr;
> > + pr_warn("*** Warning *** Using an old binding which will be deprecated\n");
> > + /* We just need the adress, we already know the size */
> > + addr = be32_to_cpu(*of_get_address(np, 0, NULL, NULL));
> > + addr -= PMSU_BASE_OFFSET;
> > + pmsu_mp_base = ioremap(addr, PMSU_REG_SIZE);
> > + of_node_put(np);
>
> When messing with OF passed resources, I suggest to use
> of_address_to_resource() and work on the struct resource
> instead. The be32_to_cpu pointing to an immediate just looks
> strange.

I'm working on a revised patch set for these PMSU changes, as I also
need them as a preparation for the SMP support on Armada 375/38x. And
my revised patch set makes the manipulations on the 'struct resource',
as you suggest.

Thomas
--
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering