[ARM] pxa: Allow platforms to override PSPR setting

Currently, we set PSPR just before entering sleep mode.  However,
some platforms have different requirements for setting PSPR in
order to properly wake up.

Set PSPR earlier in the suspend cycle so that platforms can
change the setting by using a sysdev driver instead.

Acked-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-pxa/include/mach/pm.h

@@ -15,6 +15,8 @@ struct pxa_cpu_pm_fns {
 	void	(*restore)(unsigned long *);
 	int	(*valid)(suspend_state_t state);
 	void	(*enter)(suspend_state_t state);
+	int	(*prepare)(void);
+	void	(*finish)(void);
 };
 
 extern struct pxa_cpu_pm_fns *pxa_cpu_pm_fns;

arch/arm/mach-pxa/pm.c

@@ -86,9 +86,27 @@ static int pxa_pm_valid(suspend_state_t state)
 	return -EINVAL;
 }
 
+static int pxa_pm_prepare(void)
+{
+	int ret = 0;
+
+	if (pxa_cpu_pm_fns && pxa_cpu_pm_fns->prepare)
+		ret = pxa_cpu_pm_fns->prepare();
+
+	return ret;
+}
+
+static void pxa_pm_finish(void)
+{
+	if (pxa_cpu_pm_fns && pxa_cpu_pm_fns->finish)
+		pxa_cpu_pm_fns->finish();
+}
+
 static struct platform_suspend_ops pxa_pm_ops = {
 	.valid		= pxa_pm_valid,
 	.enter		= pxa_pm_enter,
+	.prepare	= pxa_pm_prepare,
+	.finish		= pxa_pm_finish,
 };
 
 static int __init pxa_pm_init(void)

arch/arm/mach-pxa/pxa25x.c

@@ -234,9 +234,6 @@ static void pxa25x_cpu_pm_save(unsigned long *sleep_save)
 
 static void pxa25x_cpu_pm_restore(unsigned long *sleep_save)
 {
-	/* ensure not to come back here if it wasn't intended */
-	PSPR = 0;
-
 	/* restore registers */
 	RESTORE(GAFR0_L); RESTORE(GAFR0_U);
 	RESTORE(GAFR1_L); RESTORE(GAFR1_U);
@@ -256,19 +253,32 @@ static void pxa25x_cpu_pm_enter(suspend_state_t state)
 
 	switch (state) {
 	case PM_SUSPEND_MEM:
-		/* set resume return address */
-		PSPR = virt_to_phys(pxa_cpu_resume);
 		pxa25x_cpu_suspend(PWRMODE_SLEEP);
 		break;
 	}
 }
 
+static int pxa25x_cpu_pm_prepare(void)
+{
+	/* set resume return address */
+	PSPR = virt_to_phys(pxa_cpu_resume);
+	return 0;
+}
+
+static void pxa25x_cpu_pm_finish(void)
+{
+	/* ensure not to come back here if it wasn't intended */
+	PSPR = 0;
+}
+
 static struct pxa_cpu_pm_fns pxa25x_cpu_pm_fns = {
 	.save_count	= SLEEP_SAVE_COUNT,
 	.valid		= suspend_valid_only_mem,
 	.save		= pxa25x_cpu_pm_save,
 	.restore	= pxa25x_cpu_pm_restore,
 	.enter		= pxa25x_cpu_pm_enter,
+	.prepare	= pxa25x_cpu_pm_prepare,
+	.finish		= pxa25x_cpu_pm_finish,
 };
 
 static void __init pxa25x_init_pm(void)

arch/arm/mach-pxa/pxa27x.c

@@ -220,9 +220,6 @@ void pxa27x_cpu_pm_save(unsigned long *sleep_save)
 
 void pxa27x_cpu_pm_restore(unsigned long *sleep_save)
 {
-	/* ensure not to come back here if it wasn't intended */
-	PSPR = 0;
-
 	/* restore registers */
 	RESTORE(GAFR0_L); RESTORE(GAFR0_U);
 	RESTORE(GAFR1_L); RESTORE(GAFR1_U);
@@ -259,8 +256,6 @@ void pxa27x_cpu_pm_enter(suspend_state_t state)
 		pxa_cpu_standby();
 		break;
 	case PM_SUSPEND_MEM:
-		/* set resume return address */
-		PSPR = virt_to_phys(pxa_cpu_resume);
 		pxa27x_cpu_suspend(PWRMODE_SLEEP);
 		break;
 	}
@@ -271,12 +266,27 @@ static int pxa27x_cpu_pm_valid(suspend_state_t state)
 	return state == PM_SUSPEND_MEM || state == PM_SUSPEND_STANDBY;
 }
 
+static int pxa27x_cpu_pm_prepare(void)
+{
+	/* set resume return address */
+	PSPR = virt_to_phys(pxa_cpu_resume);
+	return 0;
+}
+
+static void pxa27x_cpu_pm_finish(void)
+{
+	/* ensure not to come back here if it wasn't intended */
+	PSPR = 0;
+}
+
 static struct pxa_cpu_pm_fns pxa27x_cpu_pm_fns = {
 	.save_count	= SLEEP_SAVE_COUNT,
 	.save		= pxa27x_cpu_pm_save,
 	.restore	= pxa27x_cpu_pm_restore,
 	.valid		= pxa27x_cpu_pm_valid,
 	.enter		= pxa27x_cpu_pm_enter,
+	.prepare	= pxa27x_cpu_pm_prepare,
+	.finish		= pxa27x_cpu_pm_finish,
 };
 
 static void __init pxa27x_init_pm(void)