From a21765a70ec06be175d3997320a83fa66fcc8955 Mon Sep 17 00:00:00 2001
From: Ben Dooks <ben-linux@fluff.org>
Date: Sun, 11 Feb 2007 18:31:01 +0100
Subject: [ARM] 4157/2: S3C24XX: move arch/arch/mach-s3c2410 into cpu
 components

The following patch and script moves the arch/arm/mach-s3c2410
directory into arch/arm/plat-s3c24xx for the generic core code
and inti arch/arm/mach-s3c{cpu} for the cpu/machine support files

Include directory include/asm-arm/plat-s3c24xx is added for the
core include files.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/plat-s3c24xx/pm.c | 659 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 659 insertions(+)
 create mode 100644 arch/arm/plat-s3c24xx/pm.c

(limited to 'arch/arm/plat-s3c24xx/pm.c')

diff --git a/arch/arm/plat-s3c24xx/pm.c b/arch/arm/plat-s3c24xx/pm.c
new file mode 100644
index 000000000000..ecf68d611904
--- /dev/null
+++ b/arch/arm/plat-s3c24xx/pm.c
@@ -0,0 +1,659 @@
+/* linux/arch/arm/plat-s3c24xx/pm.c
+ *
+ * Copyright (c) 2004,2006 Simtec Electronics
+ *	Ben Dooks <ben@simtec.co.uk>
+ *
+ * S3C24XX Power Manager (Suspend-To-RAM) support
+ *
+ * See Documentation/arm/Samsung-S3C24XX/Suspend.txt for more information
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Parts based on arch/arm/mach-pxa/pm.c
+ *
+ * Thanks to Dimitry Andric for debugging
+*/
+
+#include <linux/init.h>
+#include <linux/suspend.h>
+#include <linux/errno.h>
+#include <linux/time.h>
+#include <linux/interrupt.h>
+#include <linux/crc32.h>
+#include <linux/ioport.h>
+#include <linux/delay.h>
+#include <linux/serial_core.h>
+
+#include <asm/cacheflush.h>
+#include <asm/hardware.h>
+#include <asm/io.h>
+
+#include <asm/arch/regs-serial.h>
+#include <asm/arch/regs-clock.h>
+#include <asm/arch/regs-gpio.h>
+#include <asm/arch/regs-mem.h>
+#include <asm/arch/regs-irq.h>
+
+#include <asm/mach/time.h>
+
+#include <asm/plat-s3c24xx/pm.h>
+
+/* for external use */
+
+unsigned long s3c_pm_flags;
+
+#define PFX "s3c24xx-pm: "
+
+static struct sleep_save core_save[] = {
+	SAVE_ITEM(S3C2410_LOCKTIME),
+	SAVE_ITEM(S3C2410_CLKCON),
+
+	/* we restore the timings here, with the proviso that the board
+	 * brings the system up in an slower, or equal frequency setting
+	 * to the original system.
+	 *
+	 * if we cannot guarantee this, then things are going to go very
+	 * wrong here, as we modify the refresh and both pll settings.
+	 */
+
+	SAVE_ITEM(S3C2410_BWSCON),
+	SAVE_ITEM(S3C2410_BANKCON0),
+	SAVE_ITEM(S3C2410_BANKCON1),
+	SAVE_ITEM(S3C2410_BANKCON2),
+	SAVE_ITEM(S3C2410_BANKCON3),
+	SAVE_ITEM(S3C2410_BANKCON4),
+	SAVE_ITEM(S3C2410_BANKCON5),
+
+	SAVE_ITEM(S3C2410_CLKDIVN),
+	SAVE_ITEM(S3C2410_MPLLCON),
+	SAVE_ITEM(S3C2410_UPLLCON),
+	SAVE_ITEM(S3C2410_CLKSLOW),
+	SAVE_ITEM(S3C2410_REFRESH),
+};
+
+static struct sleep_save gpio_save[] = {
+	SAVE_ITEM(S3C2410_GPACON),
+	SAVE_ITEM(S3C2410_GPADAT),
+
+	SAVE_ITEM(S3C2410_GPBCON),
+	SAVE_ITEM(S3C2410_GPBDAT),
+	SAVE_ITEM(S3C2410_GPBUP),
+
+	SAVE_ITEM(S3C2410_GPCCON),
+	SAVE_ITEM(S3C2410_GPCDAT),
+	SAVE_ITEM(S3C2410_GPCUP),
+
+	SAVE_ITEM(S3C2410_GPDCON),
+	SAVE_ITEM(S3C2410_GPDDAT),
+	SAVE_ITEM(S3C2410_GPDUP),
+
+	SAVE_ITEM(S3C2410_GPECON),
+	SAVE_ITEM(S3C2410_GPEDAT),
+	SAVE_ITEM(S3C2410_GPEUP),
+
+	SAVE_ITEM(S3C2410_GPFCON),
+	SAVE_ITEM(S3C2410_GPFDAT),
+	SAVE_ITEM(S3C2410_GPFUP),
+
+	SAVE_ITEM(S3C2410_GPGCON),
+	SAVE_ITEM(S3C2410_GPGDAT),
+	SAVE_ITEM(S3C2410_GPGUP),
+
+	SAVE_ITEM(S3C2410_GPHCON),
+	SAVE_ITEM(S3C2410_GPHDAT),
+	SAVE_ITEM(S3C2410_GPHUP),
+
+	SAVE_ITEM(S3C2410_DCLKCON),
+};
+
+#ifdef CONFIG_S3C2410_PM_DEBUG
+
+#define SAVE_UART(va) \
+	SAVE_ITEM((va) + S3C2410_ULCON), \
+	SAVE_ITEM((va) + S3C2410_UCON), \
+	SAVE_ITEM((va) + S3C2410_UFCON), \
+	SAVE_ITEM((va) + S3C2410_UMCON), \
+	SAVE_ITEM((va) + S3C2410_UBRDIV)
+
+static struct sleep_save uart_save[] = {
+	SAVE_UART(S3C24XX_VA_UART0),
+	SAVE_UART(S3C24XX_VA_UART1),
+#ifndef CONFIG_CPU_S3C2400
+	SAVE_UART(S3C24XX_VA_UART2),
+#endif
+};
+
+/* debug
+ *
+ * we send the debug to printascii() to allow it to be seen if the
+ * system never wakes up from the sleep
+*/
+
+extern void printascii(const char *);
+
+void pm_dbg(const char *fmt, ...)
+{
+	va_list va;
+	char buff[256];
+
+	va_start(va, fmt);
+	vsprintf(buff, fmt, va);
+	va_end(va);
+
+	printascii(buff);
+}
+
+static void s3c2410_pm_debug_init(void)
+{
+	unsigned long tmp = __raw_readl(S3C2410_CLKCON);
+
+	/* re-start uart clocks */
+	tmp |= S3C2410_CLKCON_UART0;
+	tmp |= S3C2410_CLKCON_UART1;
+	tmp |= S3C2410_CLKCON_UART2;
+
+	__raw_writel(tmp, S3C2410_CLKCON);
+	udelay(10);
+}
+
+#define DBG(fmt...) pm_dbg(fmt)
+#else
+#define DBG(fmt...) printk(KERN_DEBUG fmt)
+
+#define s3c2410_pm_debug_init() do { } while(0)
+
+static struct sleep_save uart_save[] = {};
+#endif
+
+#if defined(CONFIG_S3C2410_PM_CHECK) && CONFIG_S3C2410_PM_CHECK_CHUNKSIZE != 0
+
+/* suspend checking code...
+ *
+ * this next area does a set of crc checks over all the installed
+ * memory, so the system can verify if the resume was ok.
+ *
+ * CONFIG_S3C2410_PM_CHECK_CHUNKSIZE defines the block-size for the CRC,
+ * increasing it will mean that the area corrupted will be less easy to spot,
+ * and reducing the size will cause the CRC save area to grow
+*/
+
+#define CHECK_CHUNKSIZE (CONFIG_S3C2410_PM_CHECK_CHUNKSIZE * 1024)
+
+static u32 crc_size;	/* size needed for the crc block */
+static u32 *crcs;	/* allocated over suspend/resume */
+
+typedef u32 *(run_fn_t)(struct resource *ptr, u32 *arg);
+
+/* s3c2410_pm_run_res
+ *
+ * go thorugh the given resource list, and look for system ram
+*/
+
+static void s3c2410_pm_run_res(struct resource *ptr, run_fn_t fn, u32 *arg)
+{
+	while (ptr != NULL) {
+		if (ptr->child != NULL)
+			s3c2410_pm_run_res(ptr->child, fn, arg);
+
+		if ((ptr->flags & IORESOURCE_MEM) &&
+		    strcmp(ptr->name, "System RAM") == 0) {
+			DBG("Found system RAM at %08lx..%08lx\n",
+			    ptr->start, ptr->end);
+			arg = (fn)(ptr, arg);
+		}
+
+		ptr = ptr->sibling;
+	}
+}
+
+static void s3c2410_pm_run_sysram(run_fn_t fn, u32 *arg)
+{
+	s3c2410_pm_run_res(&iomem_resource, fn, arg);
+}
+
+static u32 *s3c2410_pm_countram(struct resource *res, u32 *val)
+{
+	u32 size = (u32)(res->end - res->start)+1;
+
+	size += CHECK_CHUNKSIZE-1;
+	size /= CHECK_CHUNKSIZE;
+
+	DBG("Area %08lx..%08lx, %d blocks\n", res->start, res->end, size);
+
+	*val += size * sizeof(u32);
+	return val;
+}
+
+/* s3c2410_pm_prepare_check
+ *
+ * prepare the necessary information for creating the CRCs. This
+ * must be done before the final save, as it will require memory
+ * allocating, and thus touching bits of the kernel we do not
+ * know about.
+*/
+
+static void s3c2410_pm_check_prepare(void)
+{
+	crc_size = 0;
+
+	s3c2410_pm_run_sysram(s3c2410_pm_countram, &crc_size);
+
+	DBG("s3c2410_pm_prepare_check: %u checks needed\n", crc_size);
+
+	crcs = kmalloc(crc_size+4, GFP_KERNEL);
+	if (crcs == NULL)
+		printk(KERN_ERR "Cannot allocated CRC save area\n");
+}
+
+static u32 *s3c2410_pm_makecheck(struct resource *res, u32 *val)
+{
+	unsigned long addr, left;
+
+	for (addr = res->start; addr < res->end;
+	     addr += CHECK_CHUNKSIZE) {
+		left = res->end - addr;
+
+		if (left > CHECK_CHUNKSIZE)
+			left = CHECK_CHUNKSIZE;
+
+		*val = crc32_le(~0, phys_to_virt(addr), left);
+		val++;
+	}
+
+	return val;
+}
+
+/* s3c2410_pm_check_store
+ *
+ * compute the CRC values for the memory blocks before the final
+ * sleep.
+*/
+
+static void s3c2410_pm_check_store(void)
+{
+	if (crcs != NULL)
+		s3c2410_pm_run_sysram(s3c2410_pm_makecheck, crcs);
+}
+
+/* in_region
+ *
+ * return TRUE if the area defined by ptr..ptr+size contatins the
+ * what..what+whatsz
+*/
+
+static inline int in_region(void *ptr, int size, void *what, size_t whatsz)
+{
+	if ((what+whatsz) < ptr)
+		return 0;
+
+	if (what > (ptr+size))
+		return 0;
+
+	return 1;
+}
+
+static u32 *s3c2410_pm_runcheck(struct resource *res, u32 *val)
+{
+	void *save_at = phys_to_virt(s3c2410_sleep_save_phys);
+	unsigned long addr;
+	unsigned long left;
+	void *ptr;
+	u32 calc;
+
+	for (addr = res->start; addr < res->end;
+	     addr += CHECK_CHUNKSIZE) {
+		left = res->end - addr;
+
+		if (left > CHECK_CHUNKSIZE)
+			left = CHECK_CHUNKSIZE;
+
+		ptr = phys_to_virt(addr);
+
+		if (in_region(ptr, left, crcs, crc_size)) {
+			DBG("skipping %08lx, has crc block in\n", addr);
+			goto skip_check;
+		}
+
+		if (in_region(ptr, left, save_at, 32*4 )) {
+			DBG("skipping %08lx, has save block in\n", addr);
+			goto skip_check;
+		}
+
+		/* calculate and check the checksum */
+
+		calc = crc32_le(~0, ptr, left);
+		if (calc != *val) {
+			printk(KERN_ERR PFX "Restore CRC error at "
+			       "%08lx (%08x vs %08x)\n", addr, calc, *val);
+
+			DBG("Restore CRC error at %08lx (%08x vs %08x)\n",
+			    addr, calc, *val);
+		}
+
+	skip_check:
+		val++;
+	}
+
+	return val;
+}
+
+/* s3c2410_pm_check_restore
+ *
+ * check the CRCs after the restore event and free the memory used
+ * to hold them
+*/
+
+static void s3c2410_pm_check_restore(void)
+{
+	if (crcs != NULL) {
+		s3c2410_pm_run_sysram(s3c2410_pm_runcheck, crcs);
+		kfree(crcs);
+		crcs = NULL;
+	}
+}
+
+#else
+
+#define s3c2410_pm_check_prepare() do { } while(0)
+#define s3c2410_pm_check_restore() do { } while(0)
+#define s3c2410_pm_check_store()   do { } while(0)
+#endif
+
+/* helper functions to save and restore register state */
+
+void s3c2410_pm_do_save(struct sleep_save *ptr, int count)
+{
+	for (; count > 0; count--, ptr++) {
+		ptr->val = __raw_readl(ptr->reg);
+		DBG("saved %p value %08lx\n", ptr->reg, ptr->val);
+	}
+}
+
+/* s3c2410_pm_do_restore
+ *
+ * restore the system from the given list of saved registers
+ *
+ * Note, we do not use DBG() in here, as the system may not have
+ * restore the UARTs state yet
+*/
+
+void s3c2410_pm_do_restore(struct sleep_save *ptr, int count)
+{
+	for (; count > 0; count--, ptr++) {
+		printk(KERN_DEBUG "restore %p (restore %08lx, was %08x)\n",
+		       ptr->reg, ptr->val, __raw_readl(ptr->reg));
+
+		__raw_writel(ptr->val, ptr->reg);
+	}
+}
+
+/* s3c2410_pm_do_restore_core
+ *
+ * similar to s3c2410_pm_do_restore_core
+ *
+ * WARNING: Do not put any debug in here that may effect memory or use
+ * peripherals, as things may be changing!
+*/
+
+static void s3c2410_pm_do_restore_core(struct sleep_save *ptr, int count)
+{
+	for (; count > 0; count--, ptr++) {
+		__raw_writel(ptr->val, ptr->reg);
+	}
+}
+
+/* s3c2410_pm_show_resume_irqs
+ *
+ * print any IRQs asserted at resume time (ie, we woke from)
+*/
+
+static void s3c2410_pm_show_resume_irqs(int start, unsigned long which,
+					unsigned long mask)
+{
+	int i;
+
+	which &= ~mask;
+
+	for (i = 0; i <= 31; i++) {
+		if ((which) & (1L<<i)) {
+			DBG("IRQ %d asserted at resume\n", start+i);
+		}
+	}
+}
+
+/* s3c2410_pm_check_resume_pin
+ *
+ * check to see if the pin is configured correctly for sleep mode, and
+ * make any necessary adjustments if it is not
+*/
+
+static void s3c2410_pm_check_resume_pin(unsigned int pin, unsigned int irqoffs)
+{
+	unsigned long irqstate;
+	unsigned long pinstate;
+	int irq = s3c2410_gpio_getirq(pin);
+
+	if (irqoffs < 4)
+		irqstate = s3c_irqwake_intmask & (1L<<irqoffs);
+	else
+		irqstate = s3c_irqwake_eintmask & (1L<<irqoffs);
+
+	pinstate = s3c2410_gpio_getcfg(pin);
+
+	if (!irqstate) {
+		if (pinstate == S3C2410_GPIO_IRQ)
+			DBG("Leaving IRQ %d (pin %d) enabled\n", irq, pin);
+	} else {
+		if (pinstate == S3C2410_GPIO_IRQ) {
+			DBG("Disabling IRQ %d (pin %d)\n", irq, pin);
+			s3c2410_gpio_cfgpin(pin, S3C2410_GPIO_INPUT);
+		}
+	}
+}
+
+/* s3c2410_pm_configure_extint
+ *
+ * configure all external interrupt pins
+*/
+
+static void s3c2410_pm_configure_extint(void)
+{
+	int pin;
+
+	/* for each of the external interrupts (EINT0..EINT15) we
+	 * need to check wether it is an external interrupt source,
+	 * and then configure it as an input if it is not
+	*/
+
+	for (pin = S3C2410_GPF0; pin <= S3C2410_GPF7; pin++) {
+		s3c2410_pm_check_resume_pin(pin, pin - S3C2410_GPF0);
+	}
+
+	for (pin = S3C2410_GPG0; pin <= S3C2410_GPG7; pin++) {
+		s3c2410_pm_check_resume_pin(pin, (pin - S3C2410_GPG0)+8);
+	}
+}
+
+void (*pm_cpu_prep)(void);
+void (*pm_cpu_sleep)(void);
+
+#define any_allowed(mask, allow) (((mask) & (allow)) != (allow))
+
+/* s3c2410_pm_enter
+ *
+ * central control for sleep/resume process
+*/
+
+static int s3c2410_pm_enter(suspend_state_t state)
+{
+	unsigned long regs_save[16];
+
+	/* ensure the debug is initialised (if enabled) */
+
+	s3c2410_pm_debug_init();
+
+	DBG("s3c2410_pm_enter(%d)\n", state);
+
+	if (pm_cpu_prep == NULL || pm_cpu_sleep == NULL) {
+		printk(KERN_ERR PFX "error: no cpu sleep functions set\n");
+		return -EINVAL;
+	}
+
+	if (state != PM_SUSPEND_MEM) {
+		printk(KERN_ERR PFX "error: only PM_SUSPEND_MEM supported\n");
+		return -EINVAL;
+	}
+
+	/* check if we have anything to wake-up with... bad things seem
+	 * to happen if you suspend with no wakeup (system will often
+	 * require a full power-cycle)
+	*/
+
+	if (!any_allowed(s3c_irqwake_intmask, s3c_irqwake_intallow) &&
+	    !any_allowed(s3c_irqwake_eintmask, s3c_irqwake_eintallow)) {
+		printk(KERN_ERR PFX "No sources enabled for wake-up!\n");
+		printk(KERN_ERR PFX "Aborting sleep\n");
+		return -EINVAL;
+	}
+
+	/* prepare check area if configured */
+
+	s3c2410_pm_check_prepare();
+
+	/* store the physical address of the register recovery block */
+
+	s3c2410_sleep_save_phys = virt_to_phys(regs_save);
+
+	DBG("s3c2410_sleep_save_phys=0x%08lx\n", s3c2410_sleep_save_phys);
+
+	/* save all necessary core registers not covered by the drivers */
+
+	s3c2410_pm_do_save(gpio_save, ARRAY_SIZE(gpio_save));
+	s3c2410_pm_do_save(core_save, ARRAY_SIZE(core_save));
+	s3c2410_pm_do_save(uart_save, ARRAY_SIZE(uart_save));
+
+	/* set the irq configuration for wake */
+
+	s3c2410_pm_configure_extint();
+
+	DBG("sleep: irq wakeup masks: %08lx,%08lx\n",
+	    s3c_irqwake_intmask, s3c_irqwake_eintmask);
+
+	__raw_writel(s3c_irqwake_intmask, S3C2410_INTMSK);
+	__raw_writel(s3c_irqwake_eintmask, S3C2410_EINTMASK);
+
+	/* ack any outstanding external interrupts before we go to sleep */
+
+	__raw_writel(__raw_readl(S3C2410_EINTPEND), S3C2410_EINTPEND);
+	__raw_writel(__raw_readl(S3C2410_INTPND), S3C2410_INTPND);
+	__raw_writel(__raw_readl(S3C2410_SRCPND), S3C2410_SRCPND);
+
+	/* call cpu specific preperation */
+
+	pm_cpu_prep();
+
+	/* flush cache back to ram */
+
+	flush_cache_all();
+
+	s3c2410_pm_check_store();
+
+	/* send the cpu to sleep... */
+
+	__raw_writel(0x00, S3C2410_CLKCON);  /* turn off clocks over sleep */
+
+	/* s3c2410_cpu_save will also act as our return point from when
+	 * we resume as it saves its own register state, so use the return
+	 * code to differentiate return from save and return from sleep */
+
+	if (s3c2410_cpu_save(regs_save) == 0) {
+		flush_cache_all();
+		pm_cpu_sleep();
+	}
+
+	/* restore the cpu state */
+
+	cpu_init();
+
+	/* restore the system state */
+
+	s3c2410_pm_do_restore_core(core_save, ARRAY_SIZE(core_save));
+	s3c2410_pm_do_restore(gpio_save, ARRAY_SIZE(gpio_save));
+	s3c2410_pm_do_restore(uart_save, ARRAY_SIZE(uart_save));
+
+	s3c2410_pm_debug_init();
+
+	/* check what irq (if any) restored the system */
+
+	DBG("post sleep: IRQs 0x%08x, 0x%08x\n",
+	    __raw_readl(S3C2410_SRCPND),
+	    __raw_readl(S3C2410_EINTPEND));
+
+	s3c2410_pm_show_resume_irqs(IRQ_EINT0, __raw_readl(S3C2410_SRCPND),
+				    s3c_irqwake_intmask);
+
+	s3c2410_pm_show_resume_irqs(IRQ_EINT4-4, __raw_readl(S3C2410_EINTPEND),
+				    s3c_irqwake_eintmask);
+
+	DBG("post sleep, preparing to return\n");
+
+	s3c2410_pm_check_restore();
+
+	/* ok, let's return from sleep */
+
+	DBG("S3C2410 PM Resume (post-restore)\n");
+	return 0;
+}
+
+/*
+ * Called after processes are frozen, but before we shut down devices.
+ */
+static int s3c2410_pm_prepare(suspend_state_t state)
+{
+	return 0;
+}
+
+/*
+ * Called after devices are re-setup, but before processes are thawed.
+ */
+static int s3c2410_pm_finish(suspend_state_t state)
+{
+	return 0;
+}
+
+/*
+ * Set to PM_DISK_FIRMWARE so we can quickly veto suspend-to-disk.
+ */
+static struct pm_ops s3c2410_pm_ops = {
+	.pm_disk_mode	= PM_DISK_FIRMWARE,
+	.prepare	= s3c2410_pm_prepare,
+	.enter		= s3c2410_pm_enter,
+	.finish		= s3c2410_pm_finish,
+};
+
+/* s3c2410_pm_init
+ *
+ * Attach the power management functions. This should be called
+ * from the board specific initialisation if the board supports
+ * it.
+*/
+
+int __init s3c2410_pm_init(void)
+{
+	printk("S3C2410 Power Management, (c) 2004 Simtec Electronics\n");
+
+	pm_set_ops(&s3c2410_pm_ops);
+	return 0;
+}
-- 
cgit v1.2.3


From fe0c935a6cbf25d72a27c7a345df8a2151de0b74 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes@sipsolutions.net>
Date: Mon, 30 Apr 2007 15:09:51 -0700
Subject: 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>
---
 arch/arm/common/sharpsl_pm.c |  1 -
 arch/arm/mach-at91/pm.c      |  1 -
 arch/arm/mach-omap1/pm.c     |  1 -
 arch/arm/mach-omap2/pm.c     |  1 -
 arch/arm/mach-pxa/pm.c       |  4 ---
 arch/arm/mach-sa1100/pm.c    |  7 ------
 arch/arm/plat-s3c24xx/pm.c   |  9 -------
 arch/sh/boards/hp6xx/pm.c    |  7 ------
 include/linux/pm.h           | 23 +++++++++--------
 kernel/power/disk.c          | 60 ++++++++++++++++++++++++++++----------------
 kernel/power/main.c          |  6 ++++-
 11 files changed, 56 insertions(+), 64 deletions(-)

(limited to 'arch/arm/plat-s3c24xx/pm.c')

diff --git a/arch/arm/common/sharpsl_pm.c b/arch/arm/common/sharpsl_pm.c
index a9bc5b52218f..4cb895d4ae5b 100644
--- a/arch/arm/common/sharpsl_pm.c
+++ b/arch/arm/common/sharpsl_pm.c
@@ -766,7 +766,6 @@ static void sharpsl_apm_get_power_status(struct apm_power_info *info)
 }
 
 static struct pm_ops sharpsl_pm_ops = {
-	.pm_disk_mode	= PM_DISK_FIRMWARE,
 	.prepare	= pxa_pm_prepare,
 	.enter		= corgi_pxa_pm_enter,
 	.finish		= pxa_pm_finish,
diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
index b49bfda53d7f..ff8db29e989e 100644
--- a/arch/arm/mach-at91/pm.c
+++ b/arch/arm/mach-at91/pm.c
@@ -201,7 +201,6 @@ error:
 
 
 static struct pm_ops at91_pm_ops ={
-	.pm_disk_mode	= 0,
 	.valid		= at91_pm_valid_state,
 	.prepare	= at91_pm_prepare,
 	.enter		= at91_pm_enter,
diff --git a/arch/arm/mach-omap1/pm.c b/arch/arm/mach-omap1/pm.c
index 49efe903dacd..4248117e5e3f 100644
--- a/arch/arm/mach-omap1/pm.c
+++ b/arch/arm/mach-omap1/pm.c
@@ -698,7 +698,6 @@ static struct irqaction omap_wakeup_irq = {
 
 
 static struct pm_ops omap_pm_ops ={
-	.pm_disk_mode	= 0,
 	.prepare	= omap_pm_prepare,
 	.enter		= omap_pm_enter,
 	.finish		= omap_pm_finish,
diff --git a/arch/arm/mach-omap2/pm.c b/arch/arm/mach-omap2/pm.c
index d7eee99b7e3f..3e9a128feea1 100644
--- a/arch/arm/mach-omap2/pm.c
+++ b/arch/arm/mach-omap2/pm.c
@@ -370,7 +370,6 @@ static int omap2_pm_finish(suspend_state_t state)
 }
 
 static struct pm_ops omap_pm_ops = {
-	.pm_disk_mode	= 0,
 	.prepare	= omap2_pm_prepare,
 	.enter		= omap2_pm_enter,
 	.finish		= omap2_pm_finish,
diff --git a/arch/arm/mach-pxa/pm.c b/arch/arm/mach-pxa/pm.c
index b4d8276d6050..0a99ef43b36f 100644
--- a/arch/arm/mach-pxa/pm.c
+++ b/arch/arm/mach-pxa/pm.c
@@ -223,11 +223,7 @@ int pxa_pm_finish(suspend_state_t state)
 
 EXPORT_SYMBOL_GPL(pxa_pm_finish);
 
-/*
- * Set to PM_DISK_FIRMWARE so we can quickly veto suspend-to-disk.
- */
 static struct pm_ops pxa_pm_ops = {
-	.pm_disk_mode	= PM_DISK_FIRMWARE,
 	.prepare	= pxa_pm_prepare,
 	.enter		= pxa_pm_enter,
 	.finish		= pxa_pm_finish,
diff --git a/arch/arm/mach-sa1100/pm.c b/arch/arm/mach-sa1100/pm.c
index 786c8534231f..b0837113b2aa 100644
--- a/arch/arm/mach-sa1100/pm.c
+++ b/arch/arm/mach-sa1100/pm.c
@@ -59,9 +59,6 @@ static int sa11x0_pm_enter(suspend_state_t state)
 	unsigned long gpio, sleep_save[SLEEP_SAVE_SIZE];
 	struct timespec delta, rtc;
 
-	if (state != PM_SUSPEND_MEM)
-		return -EINVAL;
-
 	/* preserve current time */
 	rtc.tv_sec = RCNR;
 	rtc.tv_nsec = 0;
@@ -134,11 +131,7 @@ unsigned long sleep_phys_sp(void *sp)
 	return virt_to_phys(sp);
 }
 
-/*
- * Set to PM_DISK_FIRMWARE so we can quickly veto suspend-to-disk.
- */
 static struct pm_ops sa11x0_pm_ops = {
-	.pm_disk_mode	= PM_DISK_FIRMWARE,
 	.enter		= sa11x0_pm_enter,
 };
 
diff --git a/arch/arm/plat-s3c24xx/pm.c b/arch/arm/plat-s3c24xx/pm.c
index ecf68d611904..d6af3082af30 100644
--- a/arch/arm/plat-s3c24xx/pm.c
+++ b/arch/arm/plat-s3c24xx/pm.c
@@ -511,11 +511,6 @@ static int s3c2410_pm_enter(suspend_state_t state)
 		return -EINVAL;
 	}
 
-	if (state != PM_SUSPEND_MEM) {
-		printk(KERN_ERR PFX "error: only PM_SUSPEND_MEM supported\n");
-		return -EINVAL;
-	}
-
 	/* check if we have anything to wake-up with... bad things seem
 	 * to happen if you suspend with no wakeup (system will often
 	 * require a full power-cycle)
@@ -633,11 +628,7 @@ static int s3c2410_pm_finish(suspend_state_t state)
 	return 0;
 }
 
-/*
- * Set to PM_DISK_FIRMWARE so we can quickly veto suspend-to-disk.
- */
 static struct pm_ops s3c2410_pm_ops = {
-	.pm_disk_mode	= PM_DISK_FIRMWARE,
 	.prepare	= s3c2410_pm_prepare,
 	.enter		= s3c2410_pm_enter,
 	.finish		= s3c2410_pm_finish,
diff --git a/arch/sh/boards/hp6xx/pm.c b/arch/sh/boards/hp6xx/pm.c
index d1947732fb3e..4b2f29a4bde9 100644
--- a/arch/sh/boards/hp6xx/pm.c
+++ b/arch/sh/boards/hp6xx/pm.c
@@ -27,9 +27,6 @@ static int hp6x0_pm_enter(suspend_state_t state)
 	u16 hd64461_stbcr;
 #endif
 
-	if (state != PM_SUSPEND_MEM)
-		return -EINVAL;
-
 #ifdef CONFIG_HD64461_ENABLER
 	outb(0, HD64461_PCC1CSCIER);
 
@@ -70,11 +67,7 @@ static int hp6x0_pm_enter(suspend_state_t state)
 	return 0;
 }
 
-/*
- * Set to PM_DISK_FIRMWARE so we can quickly veto suspend-to-disk.
- */
 static struct pm_ops hp6x0_pm_ops = {
-	.pm_disk_mode	= PM_DISK_FIRMWARE,
 	.enter		= hp6x0_pm_enter,
 };
 
diff --git a/include/linux/pm.h b/include/linux/pm.h
index 9bd86db4d395..dfced9188bdc 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -112,6 +112,8 @@ typedef int __bitwise suspend_state_t;
 
 typedef int __bitwise suspend_disk_method_t;
 
+/* invalid must be 0 so struct pm_ops initialisers can leave it out */
+#define PM_DISK_INVALID		((__force suspend_disk_method_t) 0)
 #define	PM_DISK_FIRMWARE	((__force suspend_disk_method_t) 1)
 #define	PM_DISK_PLATFORM	((__force suspend_disk_method_t) 2)
 #define	PM_DISK_SHUTDOWN	((__force suspend_disk_method_t) 3)
@@ -137,17 +139,16 @@ typedef int __bitwise suspend_disk_method_t;
  * @finish: Called when the system has left the given state and all devices
  *	are resumed. The return value is ignored.
  *
- * @pm_disk_mode: Set to the disk method that the user should be able to
- *	configure for suspend-to-disk. Since %PM_DISK_SHUTDOWN,
- *	%PM_DISK_REBOOT, %PM_DISK_TEST and %PM_DISK_TESTPROC
- *	are always allowed, currently only %PM_DISK_PLATFORM
- *	makes sense. If the user then choses %PM_DISK_PLATFORM,
- *	the @prepare call will be called before suspending to disk
- *	(if present), the @enter call should be present and will
- *	be called after all state has been saved and the machine
- *	is ready to be shut down/suspended/..., and the @finish
- *	callback is called after state has been restored. All
- *	these calls are called with %PM_SUSPEND_DISK as the state.
+ * @pm_disk_mode: The generic code always allows one of the shutdown methods
+ *	%PM_DISK_SHUTDOWN, %PM_DISK_REBOOT, %PM_DISK_TEST and
+ *	%PM_DISK_TESTPROC. If this variable is set, the mode it is set
+ *	to is allowed in addition to those modes and is also made default.
+ *	When this mode is sent selected, the @prepare call will be called
+ *	before suspending to disk (if present), the @enter call should be
+ *	present and will be called after all state has been saved and the
+ *	machine is ready to be powered off; the @finish callback is called
+ *	after state has been restored. All these calls are called with
+ *	%PM_SUSPEND_DISK as the state.
  */
 struct pm_ops {
 	int (*valid)(suspend_state_t state);
diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index aec19b063e3f..4de2f69fe095 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -39,7 +39,13 @@ static inline int platform_prepare(void)
 {
 	int error = 0;
 
-	if (pm_disk_mode == PM_DISK_PLATFORM) {
+	switch (pm_disk_mode) {
+	case PM_DISK_TEST:
+	case PM_DISK_TESTPROC:
+	case PM_DISK_SHUTDOWN:
+	case PM_DISK_REBOOT:
+		break;
+	default:
 		if (pm_ops && pm_ops->prepare)
 			error = pm_ops->prepare(PM_SUSPEND_DISK);
 	}
@@ -48,40 +54,48 @@ static inline int platform_prepare(void)
 
 /**
  *	power_down - Shut machine down for hibernate.
- *	@mode:		Suspend-to-disk mode
  *
- *	Use the platform driver, if configured so, and return gracefully if it
- *	fails.
- *	Otherwise, try to power off and reboot. If they fail, halt the machine,
- *	there ain't no turning back.
+ *	Use the platform driver, if configured so; otherwise try
+ *	to power off or reboot.
  */
 
-static void power_down(suspend_disk_method_t mode)
+static void power_down(void)
 {
-	switch(mode) {
-	case PM_DISK_PLATFORM:
-		if (pm_ops && pm_ops->enter) {
-			kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
-			pm_ops->enter(PM_SUSPEND_DISK);
-			break;
-		}
+	switch (pm_disk_mode) {
+	case PM_DISK_TEST:
+	case PM_DISK_TESTPROC:
+		break;
 	case PM_DISK_SHUTDOWN:
 		kernel_power_off();
 		break;
 	case PM_DISK_REBOOT:
 		kernel_restart(NULL);
 		break;
+	default:
+		if (pm_ops && pm_ops->enter) {
+			kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
+			pm_ops->enter(PM_SUSPEND_DISK);
+			break;
+		}
 	}
 	kernel_halt();
-	/* Valid image is on the disk, if we continue we risk serious data corruption
-	   after resume. */
+	/*
+	 * Valid image is on the disk, if we continue we risk serious data
+	 * corruption after resume.
+	 */
 	printk(KERN_CRIT "Please power me down manually\n");
 	while(1);
 }
 
 static inline void platform_finish(void)
 {
-	if (pm_disk_mode == PM_DISK_PLATFORM) {
+	switch (pm_disk_mode) {
+	case PM_DISK_TEST:
+	case PM_DISK_TESTPROC:
+	case PM_DISK_SHUTDOWN:
+	case PM_DISK_REBOOT:
+		break;
+	default:
 		if (pm_ops && pm_ops->finish)
 			pm_ops->finish(PM_SUSPEND_DISK);
 	}
@@ -166,7 +180,7 @@ int pm_suspend_disk(void)
 		pr_debug("PM: writing image.\n");
 		error = swsusp_write();
 		if (!error)
-			power_down(pm_disk_mode);
+			power_down();
 		else {
 			swsusp_free();
 			goto Thaw;
@@ -338,10 +352,14 @@ static ssize_t disk_store(struct subsystem * s, const char * buf, size_t n)
 		}
 	}
 	if (mode) {
-		if (mode == PM_DISK_SHUTDOWN || mode == PM_DISK_REBOOT ||
-		     mode == PM_DISK_TEST || mode == PM_DISK_TESTPROC) {
+		switch (mode) {
+		case PM_DISK_SHUTDOWN:
+		case PM_DISK_REBOOT:
+		case PM_DISK_TEST:
+		case PM_DISK_TESTPROC:
 			pm_disk_mode = mode;
-		} else {
+			break;
+		default:
 			if (pm_ops && pm_ops->enter &&
 			    (mode == pm_ops->pm_disk_mode))
 				pm_disk_mode = mode;
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 3062e940d1fa..053c0a7d7f57 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -30,7 +30,7 @@
 DEFINE_MUTEX(pm_mutex);
 
 struct pm_ops *pm_ops;
-suspend_disk_method_t pm_disk_mode = PM_DISK_PLATFORM;
+suspend_disk_method_t pm_disk_mode = PM_DISK_SHUTDOWN;
 
 /**
  *	pm_set_ops - Set the global power method table. 
@@ -41,6 +41,10 @@ void pm_set_ops(struct pm_ops * ops)
 {
 	mutex_lock(&pm_mutex);
 	pm_ops = ops;
+	if (ops && ops->pm_disk_mode != PM_DISK_INVALID) {
+		pm_disk_mode = ops->pm_disk_mode;
+	} else
+		pm_disk_mode = PM_DISK_SHUTDOWN;
 	mutex_unlock(&pm_mutex);
 }
 
-- 
cgit v1.2.3


From e8c9c502690efd24b7055bf608e7a3c34216848b Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes@sipsolutions.net>
Date: Mon, 30 Apr 2007 15:09:54 -0700
Subject: power management: implement pm_ops.valid for everybody

Almost all users of pm_ops only support mem sleep, don't check in .valid and
don't reject any others in .prepare so users can be confused if they check
/sys/power/state, especially when new states are added (these would then
result in s-t-r although they're supposed to be something different).

This patch implements a generic pm_valid_only_mem function that is then
exported for users and puts it to use in almost all existing pm_ops.

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>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 arch/arm/common/sharpsl_pm.c |  1 +
 arch/arm/mach-omap1/pm.c     |  1 +
 arch/arm/mach-omap2/pm.c     |  1 +
 arch/arm/mach-pnx4008/pm.c   | 39 ++++-----------------------------------
 arch/arm/mach-pxa/pm.c       |  1 +
 arch/arm/mach-sa1100/pm.c    |  1 +
 arch/arm/plat-s3c24xx/pm.c   | 19 +------------------
 arch/sh/boards/hp6xx/pm.c    |  1 +
 drivers/acpi/sleep/main.c    | 13 +++++++++++--
 include/linux/pm.h           |  4 ++++
 kernel/power/main.c          | 13 +++++++++++++
 11 files changed, 39 insertions(+), 55 deletions(-)

(limited to 'arch/arm/plat-s3c24xx/pm.c')

diff --git a/arch/arm/common/sharpsl_pm.c b/arch/arm/common/sharpsl_pm.c
index 4cb895d4ae5b..5972df2b9af4 100644
--- a/arch/arm/common/sharpsl_pm.c
+++ b/arch/arm/common/sharpsl_pm.c
@@ -769,6 +769,7 @@ static struct pm_ops sharpsl_pm_ops = {
 	.prepare	= pxa_pm_prepare,
 	.enter		= corgi_pxa_pm_enter,
 	.finish		= pxa_pm_finish,
+	.valid		= pm_valid_only_mem,
 };
 
 static int __init sharpsl_pm_probe(struct platform_device *pdev)
diff --git a/arch/arm/mach-omap1/pm.c b/arch/arm/mach-omap1/pm.c
index 4248117e5e3f..0383ab334270 100644
--- a/arch/arm/mach-omap1/pm.c
+++ b/arch/arm/mach-omap1/pm.c
@@ -701,6 +701,7 @@ static struct pm_ops omap_pm_ops ={
 	.prepare	= omap_pm_prepare,
 	.enter		= omap_pm_enter,
 	.finish		= omap_pm_finish,
+	.valid		= pm_valid_only_mem,
 };
 
 static int __init omap_pm_init(void)
diff --git a/arch/arm/mach-omap2/pm.c b/arch/arm/mach-omap2/pm.c
index 3e9a128feea1..6f4a5436d0ce 100644
--- a/arch/arm/mach-omap2/pm.c
+++ b/arch/arm/mach-omap2/pm.c
@@ -373,6 +373,7 @@ static struct pm_ops omap_pm_ops = {
 	.prepare	= omap2_pm_prepare,
 	.enter		= omap2_pm_enter,
 	.finish		= omap2_pm_finish,
+	.valid		= pm_valid_only_mem,
 };
 
 int __init omap2_pm_init(void)
diff --git a/arch/arm/mach-pnx4008/pm.c b/arch/arm/mach-pnx4008/pm.c
index 3649cd3dfc9a..2a137f33f752 100644
--- a/arch/arm/mach-pnx4008/pm.c
+++ b/arch/arm/mach-pnx4008/pm.c
@@ -107,50 +107,19 @@ static int pnx4008_pm_enter(suspend_state_t state)
 	case PM_SUSPEND_MEM:
 		pnx4008_suspend();
 		break;
-	case PM_SUSPEND_DISK:
-		return -ENOTSUPP;
-	default:
-		return -EINVAL;
 	}
 	return 0;
 }
 
-/*
- * Called after processes are frozen, but before we shut down devices.
- */
-static int pnx4008_pm_prepare(suspend_state_t state)
-{
-	switch (state) {
-	case PM_SUSPEND_STANDBY:
-	case PM_SUSPEND_MEM:
-		break;
-
-	case PM_SUSPEND_DISK:
-		return -ENOTSUPP;
-		break;
-
-	default:
-		return -EINVAL;
-		break;
-	}
-	return 0;
-}
-
-/*
- * Called after devices are re-setup, but before processes are thawed.
- */
-static int pnx4008_pm_finish(suspend_state_t state)
+static int pnx4008_pm_valid(suspend_state_t state)
 {
-	return 0;
+	return (state == PM_SUSPEND_STANDBY) ||
+	       (state == PM_SUSPEND_MEM);
 }
 
-/*
- * Set to PM_DISK_FIRMWARE so we can quickly veto suspend-to-disk.
- */
 static struct pm_ops pnx4008_pm_ops = {
-	.prepare = pnx4008_pm_prepare,
 	.enter = pnx4008_pm_enter,
-	.finish = pnx4008_pm_finish,
+	.valid = pnx4008_pm_valid,
 };
 
 static int __init pnx4008_pm_init(void)
diff --git a/arch/arm/mach-pxa/pm.c b/arch/arm/mach-pxa/pm.c
index 0a99ef43b36f..6bf15ae73848 100644
--- a/arch/arm/mach-pxa/pm.c
+++ b/arch/arm/mach-pxa/pm.c
@@ -227,6 +227,7 @@ static struct pm_ops pxa_pm_ops = {
 	.prepare	= pxa_pm_prepare,
 	.enter		= pxa_pm_enter,
 	.finish		= pxa_pm_finish,
+	.valid		= pm_valid_only_mem,
 };
 
 static int __init pxa_pm_init(void)
diff --git a/arch/arm/mach-sa1100/pm.c b/arch/arm/mach-sa1100/pm.c
index b0837113b2aa..d674cf343156 100644
--- a/arch/arm/mach-sa1100/pm.c
+++ b/arch/arm/mach-sa1100/pm.c
@@ -133,6 +133,7 @@ unsigned long sleep_phys_sp(void *sp)
 
 static struct pm_ops sa11x0_pm_ops = {
 	.enter		= sa11x0_pm_enter,
+	.valid		= pm_valid_only_mem,
 };
 
 static int __init sa11x0_pm_init(void)
diff --git a/arch/arm/plat-s3c24xx/pm.c b/arch/arm/plat-s3c24xx/pm.c
index d6af3082af30..c6b03f8ab260 100644
--- a/arch/arm/plat-s3c24xx/pm.c
+++ b/arch/arm/plat-s3c24xx/pm.c
@@ -612,26 +612,9 @@ static int s3c2410_pm_enter(suspend_state_t state)
 	return 0;
 }
 
-/*
- * Called after processes are frozen, but before we shut down devices.
- */
-static int s3c2410_pm_prepare(suspend_state_t state)
-{
-	return 0;
-}
-
-/*
- * Called after devices are re-setup, but before processes are thawed.
- */
-static int s3c2410_pm_finish(suspend_state_t state)
-{
-	return 0;
-}
-
 static struct pm_ops s3c2410_pm_ops = {
-	.prepare	= s3c2410_pm_prepare,
 	.enter		= s3c2410_pm_enter,
-	.finish		= s3c2410_pm_finish,
+	.valid		= pm_valid_only_mem,
 };
 
 /* s3c2410_pm_init
diff --git a/arch/sh/boards/hp6xx/pm.c b/arch/sh/boards/hp6xx/pm.c
index 4b2f29a4bde9..8143d1b948e7 100644
--- a/arch/sh/boards/hp6xx/pm.c
+++ b/arch/sh/boards/hp6xx/pm.c
@@ -69,6 +69,7 @@ static int hp6x0_pm_enter(suspend_state_t state)
 
 static struct pm_ops hp6x0_pm_ops = {
 	.enter		= hp6x0_pm_enter,
+	.valid		= pm_valid_only_mem,
 };
 
 static int __init hp6x0_pm_init(void)
diff --git a/drivers/acpi/sleep/main.c b/drivers/acpi/sleep/main.c
index 37a0930fc0a6..f8c63410bcbf 100644
--- a/drivers/acpi/sleep/main.c
+++ b/drivers/acpi/sleep/main.c
@@ -168,9 +168,18 @@ int acpi_suspend(u32 acpi_state)
 
 static int acpi_pm_state_valid(suspend_state_t pm_state)
 {
-	u32 acpi_state = acpi_suspend_states[pm_state];
+	u32 acpi_state;
+
+	switch (pm_state) {
+	case PM_SUSPEND_ON:
+	case PM_SUSPEND_STANDBY:
+	case PM_SUSPEND_MEM:
+		acpi_state = acpi_suspend_states[pm_state];
 
-	return sleep_states[acpi_state];
+		return sleep_states[acpi_state];
+	default:
+		return 0;
+	}
 }
 
 static struct pm_ops acpi_pm_ops = {
diff --git a/include/linux/pm.h b/include/linux/pm.h
index c2a55f94c29a..6035209cf31e 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -128,6 +128,9 @@ typedef int __bitwise suspend_disk_method_t;
  *	always valid and never passed to this call.
  *	If not assigned, all suspend states are advertised as valid
  *	in /sys/power/state (but can still be rejected by prepare or enter.)
+ *	Since new states can be added for other platforms, you should
+ *	assign this callback. There is a %pm_valid_only_mem function
+ *	available if you only implemented mem sleep.
  *
  * @prepare: Prepare the platform for the given suspend state. Can return a
  *	negative error code if necessary.
@@ -165,6 +168,7 @@ extern void pm_set_ops(struct pm_ops *pm_ops);
 extern struct pm_ops *pm_ops;
 extern int pm_suspend(suspend_state_t state);
 
+extern int pm_valid_only_mem(suspend_state_t state);
 
 /**
  * arch_suspend_disable_irqs - disable IRQs for suspend
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 053c0a7d7f57..f94f4e20115a 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -48,6 +48,19 @@ void pm_set_ops(struct pm_ops * ops)
 	mutex_unlock(&pm_mutex);
 }
 
+/**
+ * pm_valid_only_mem - generic memory-only valid callback
+ *
+ * pm_ops drivers that implement mem suspend only and only need
+ * to check for that in their .valid callback can use this instead
+ * of rolling their own .valid callback.
+ */
+int pm_valid_only_mem(suspend_state_t state)
+{
+	return state == PM_SUSPEND_MEM;
+}
+
+
 static inline void pm_finish(suspend_state_t state)
 {
 	if (pm_ops->finish)
-- 
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