android_kernel_xiaomi_sm8350/arch/arm/mach-sa1100/pm.c
Johannes Berg fe0c935a6c rework pm_ops pm_disk_mode, kill misuse
This patch series cleans up some misconceptions about pm_ops.  Some users of
the pm_ops structure attempt to use it to stop the user from entering suspend
to disk, this, however, is not possible since the user can always use
"shutdown" in /sys/power/disk and then the pm_ops are never invoked.  Also,
platforms that don't support suspend to disk simply should not allow
configuring SOFTWARE_SUSPEND (read the help text on it, it only selects
suspend to disk and nothing else, all the other stuff depends on PM).

The pm_ops structure is actually intended to provide a way to enter
platform-defined sleep states (currently supported states are "standby" and
"mem" (suspend to ram)) and additionally (if SOFTWARE_SUSPEND is configured)
allows a platform to support a platform specific way to enter low-power mode
once everything has been saved to disk.  This is currently only used by ACPI
(S4).

This patch:

The pm_ops.pm_disk_mode is used in totally bogus ways since nobody really
seems to understand what it actually does.

This patch clarifies the pm_disk_mode description.

It also removes all the arm and sh users that think they can veto suspend to
disk via pm_ops; not so since the user can always do echo shutdown >
/sys/power/disk, they need to find a better way involving Kconfig or such.

ACPI is the only user left with a non-zero pm_disk_mode.

The patch also sets the default mode to shutdown again, but when a new pm_ops
is registered its pm_disk_mode is selected as default, that way the default
stays for ACPI where it is apparently required.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: David Brownell <david-b@pacbell.net>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: <linux-pm@lists.linux-foundation.org>
Cc: Len Brown <lenb@kernel.org>
Acked-by: Russell King <rmk@arm.linux.org.uk>
Cc: Greg KH <greg@kroah.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-04-30 16:40:40 -07:00

145 lines
2.8 KiB
C

/*
* SA1100 Power Management Routines
*
* Copyright (c) 2001 Cliff Brake <cbrake@accelent.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License.
*
* History:
*
* 2001-02-06: Cliff Brake Initial code
*
* 2001-02-25: Sukjae Cho <sjcho@east.isi.edu> &
* Chester Kuo <chester@linux.org.tw>
* Save more value for the resume function! Support
* Bitsy/Assabet/Freebird board
*
* 2001-08-29: Nicolas Pitre <nico@cam.org>
* Cleaned up, pushed platform dependent stuff
* in the platform specific files.
*
* 2002-05-27: Nicolas Pitre Killed sleep.h and the kmalloced save array.
* Storage is local on the stack now.
*/
#include <linux/init.h>
#include <linux/suspend.h>
#include <linux/errno.h>
#include <linux/time.h>
#include <asm/hardware.h>
#include <asm/memory.h>
#include <asm/system.h>
#include <asm/mach/time.h>
extern void sa1100_cpu_suspend(void);
extern void sa1100_cpu_resume(void);
#define SAVE(x) sleep_save[SLEEP_SAVE_##x] = x
#define RESTORE(x) x = sleep_save[SLEEP_SAVE_##x]
/*
* List of global SA11x0 peripheral registers to preserve.
* More ones like CP and general purpose register values are preserved
* on the stack and then the stack pointer is stored last in sleep.S.
*/
enum { SLEEP_SAVE_SP = 0,
SLEEP_SAVE_GPDR, SLEEP_SAVE_GAFR,
SLEEP_SAVE_PPDR, SLEEP_SAVE_PPSR, SLEEP_SAVE_PPAR, SLEEP_SAVE_PSDR,
SLEEP_SAVE_Ser1SDCR0,
SLEEP_SAVE_SIZE
};
static int sa11x0_pm_enter(suspend_state_t state)
{
unsigned long gpio, sleep_save[SLEEP_SAVE_SIZE];
struct timespec delta, rtc;
/* preserve current time */
rtc.tv_sec = RCNR;
rtc.tv_nsec = 0;
save_time_delta(&delta, &rtc);
gpio = GPLR;
/* save vital registers */
SAVE(GPDR);
SAVE(GAFR);
SAVE(PPDR);
SAVE(PPSR);
SAVE(PPAR);
SAVE(PSDR);
SAVE(Ser1SDCR0);
/* Clear previous reset status */
RCSR = RCSR_HWR | RCSR_SWR | RCSR_WDR | RCSR_SMR;
/* set resume return address */
PSPR = virt_to_phys(sa1100_cpu_resume);
/* go zzz */
sa1100_cpu_suspend();
cpu_init();
/*
* Ensure not to come back here if it wasn't intended
*/
PSPR = 0;
/*
* Ensure interrupt sources are disabled; we will re-init
* the interrupt subsystem via the device manager.
*/
ICLR = 0;
ICCR = 1;
ICMR = 0;
/* restore registers */
RESTORE(GPDR);
RESTORE(GAFR);
RESTORE(PPDR);
RESTORE(PPSR);
RESTORE(PPAR);
RESTORE(PSDR);
RESTORE(Ser1SDCR0);
GPSR = gpio;
GPCR = ~gpio;
/*
* Clear the peripheral sleep-hold bit.
*/
PSSR = PSSR_PH;
/* restore current time */
rtc.tv_sec = RCNR;
restore_time_delta(&delta, &rtc);
return 0;
}
unsigned long sleep_phys_sp(void *sp)
{
return virt_to_phys(sp);
}
static struct pm_ops sa11x0_pm_ops = {
.enter = sa11x0_pm_enter,
};
static int __init sa11x0_pm_init(void)
{
pm_set_ops(&sa11x0_pm_ops);
return 0;
}
late_initcall(sa11x0_pm_init);