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powerpc: Convert power off logic to pm_power_off

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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>
This commit is contained in:
Alexander Graf
2014-10-13 16:01:09 +02:00
committed by Michael Ellerman
parent 0df1f2487d
commit 9178ba294b
21 changed files with 66 additions and 58 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
arch/powerpc/kernel/setup-common.c
View File

@@ -139,8 +139,8 @@ void machine_restart(char *cmd)
void machine_power_off(void)
{
machine_shutdown();
if (ppc_md.power_off)
ppc_md.power_off();
if (pm_power_off)
pm_power_off();
#ifdef CONFIG_SMP
smp_send_stop();
#endif
@@ -151,7 +151,7 @@ void machine_power_off(void)
/* Used by the G5 thermal driver */
EXPORT_SYMBOL_GPL(machine_power_off);
void (*pm_power_off)(void) = machine_power_off;
void (*pm_power_off)(void);
EXPORT_SYMBOL_GPL(pm_power_off);
void machine_halt(void)