powerpc: Convert power off logic to pm_power_off

The generic Linux framework to power off the machine is a function pointer
called pm_power_off. The trick about this pointer is that device drivers can
potentially implement it rather than board files.

Today on powerpc we set pm_power_off to invoke our generic full machine power
off logic which then calls ppc_md.power_off to invoke machine specific power
off.

However, when we want to add a power off GPIO via the "gpio-poweroff" driver,
this card house falls apart. That driver only registers itself if pm_power_off
is NULL to ensure it doesn't override board specific logic. However, since we
always set pm_power_off to the generic power off logic (which will just not
power off the machine if no ppc_md.power_off call is implemented), we can't
implement power off via the generic GPIO power off driver.

To fix this up, let's get rid of the ppc_md.power_off logic and just always use
pm_power_off as was intended. Then individual drivers such as the GPIO power off
driver can implement power off logic via that function pointer.

With this patch set applied and a few patches on top of QEMU that implement a
power off GPIO on the virt e500 machine, I can successfully turn off my virtual
machine after halt.

Signed-off-by: Alexander Graf <agraf@suse.de>
[mpe: Squash into one patch and update changelog based on cover letter]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 1 insertions, 1 deletions

diff --git a/arch/powerpc/platforms/ps3/setup.c b/arch/powerpc/platforms/ps3/setup.c
index 3f509f86432c..009a2004b876 100644
--- a/arch/powerpc/platforms/ps3/setup.c
+++ b/arch/powerpc/platforms/ps3/setup.c
@@ -248,6 +248,7 @@ static int __init ps3_probe(void)
         ps3_mm_init();
         ps3_mm_vas_create(&htab_size);
         ps3_hpte_init(htab_size);
+        pm_power_off = ps3_power_off;
 
         DBG(" <- %s:%d\n", __func__, __LINE__);
         return 1;
@@ -278,7 +279,6 @@ define_machine(ps3) {
         .calibrate_decr                 = ps3_calibrate_decr,
         .progress                       = ps3_progress,
         .restart                        = ps3_restart,
-        .power_off                      = ps3_power_off,
         .halt                           = ps3_halt,
 #if defined(CONFIG_KEXEC)
         .kexec_cpu_down                 = ps3_kexec_cpu_down,