Merge branch 'tk_prm_chain_handler_devel_3.3' of git://git.pwsan.com/linux-2.6 into prcm

Conflicts:
	arch/arm/mach-omap2/Makefile

10 files changed, 856 insertions, 78 deletions

diff --git a/arch/arm/mach-omap2/Makefile b/arch/arm/mach-omap2/Makefile
index 9a6da52661c..63a5efad70e 100644
--- a/arch/arm/mach-omap2/Makefile
+++ b/arch/arm/mach-omap2/Makefile
@@ -81,6 +81,7 @@ endif
 endif
 
 # PRCM
+obj-y					+= prm_common.o
 obj-$(CONFIG_ARCH_OMAP2)		+= prcm.o cm2xxx_3xxx.o prm2xxx_3xxx.o
 obj-$(CONFIG_ARCH_OMAP3)		+= prcm.o cm2xxx_3xxx.o prm2xxx_3xxx.o \
 					   vc3xxx_data.o vp3xxx_data.o
@@ -90,7 +91,7 @@ obj-$(CONFIG_ARCH_OMAP3)		+= prcm.o cm2xxx_3xxx.o prm2xxx_3xxx.o \
 obj-$(CONFIG_ARCH_OMAP4)		+= prcm.o cm2xxx_3xxx.o cminst44xx.o \
 					   cm44xx.o prcm_mpu44xx.o \
 					   prminst44xx.o vc44xx_data.o \
-					   vp44xx_data.o
+					   vp44xx_data.o prm44xx.o
 
 # OMAP voltage domains
 voltagedomain-common			:= voltage.o vc.o vp.o
diff --git a/arch/arm/mach-omap2/mux.c b/arch/arm/mach-omap2/mux.c
index 655e9480eb9..e1cc75d1a57 100644
--- a/arch/arm/mach-omap2/mux.c
+++ b/arch/arm/mach-omap2/mux.c
@@ -32,6 +32,8 @@
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
 #include <linux/uaccess.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
 
 #include <asm/system.h>
 
@@ -39,6 +41,7 @@
 
 #include "control.h"
 #include "mux.h"
+#include "prm.h"
 
 #define OMAP_MUX_BASE_OFFSET		0x30	/* Offset from CTRL_BASE */
 #define OMAP_MUX_BASE_SZ		0x5ca
@@ -306,7 +309,8 @@ omap_hwmod_mux_init(struct omap_device_pad *bpads, int nr_pads)
 		pad->idle = bpad->idle;
 		pad->off = bpad->off;
 
-		if (pad->flags & OMAP_DEVICE_PAD_REMUX)
+		if (pad->flags &
+		    (OMAP_DEVICE_PAD_REMUX | OMAP_DEVICE_PAD_WAKEUP))
 			nr_pads_dynamic++;
 
 		pr_debug("%s: Initialized %s\n", __func__, pad->name);
@@ -331,7 +335,8 @@ omap_hwmod_mux_init(struct omap_device_pad *bpads, int nr_pads)
 	for (i = 0; i < hmux->nr_pads; i++) {
 		struct omap_device_pad *pad = &hmux->pads[i];
 
-		if (pad->flags & OMAP_DEVICE_PAD_REMUX) {
+		if (pad->flags &
+		    (OMAP_DEVICE_PAD_REMUX | OMAP_DEVICE_PAD_WAKEUP)) {
 			pr_debug("%s: pad %s tagged dynamic\n",
 					__func__, pad->name);
 			hmux->pads_dynamic[nr_pads_dynamic] = pad;
@@ -351,6 +356,78 @@ err1:
 	return NULL;
 }
 
+/**
+ * omap_hwmod_mux_scan_wakeups - omap hwmod scan wakeup pads
+ * @hmux: Pads for a hwmod
+ * @mpu_irqs: MPU irq array for a hwmod
+ *
+ * Scans the wakeup status of pads for a single hwmod.  If an irq
+ * array is defined for this mux, the parser will call the registered
+ * ISRs for corresponding pads, otherwise the parser will stop at the
+ * first wakeup active pad and return.  Returns true if there is a
+ * pending and non-served wakeup event for the mux, otherwise false.
+ */
+static bool omap_hwmod_mux_scan_wakeups(struct omap_hwmod_mux_info *hmux,
+		struct omap_hwmod_irq_info *mpu_irqs)
+{
+	int i, irq;
+	unsigned int val;
+	u32 handled_irqs = 0;
+
+	for (i = 0; i < hmux->nr_pads_dynamic; i++) {
+		struct omap_device_pad *pad = hmux->pads_dynamic[i];
+
+		if (!(pad->flags & OMAP_DEVICE_PAD_WAKEUP) ||
+		    !(pad->idle & OMAP_WAKEUP_EN))
+			continue;
+
+		val = omap_mux_read(pad->partition, pad->mux->reg_offset);
+		if (!(val & OMAP_WAKEUP_EVENT))
+			continue;
+
+		if (!hmux->irqs)
+			return true;
+
+		irq = hmux->irqs[i];
+		/* make sure we only handle each irq once */
+		if (handled_irqs & 1 << irq)
+			continue;
+
+		handled_irqs |= 1 << irq;
+
+		generic_handle_irq(mpu_irqs[irq].irq);
+	}
+
+	return false;
+}
+
+/**
+ * _omap_hwmod_mux_handle_irq - Process wakeup events for a single hwmod
+ *
+ * Checks a single hwmod for every wakeup capable pad to see if there is an
+ * active wakeup event. If this is the case, call the corresponding ISR.
+ */
+static int _omap_hwmod_mux_handle_irq(struct omap_hwmod *oh, void *data)
+{
+	if (!oh->mux || !oh->mux->enabled)
+		return 0;
+	if (omap_hwmod_mux_scan_wakeups(oh->mux, oh->mpu_irqs))
+		generic_handle_irq(oh->mpu_irqs[0].irq);
+	return 0;
+}
+
+/**
+ * omap_hwmod_mux_handle_irq - Process pad wakeup irqs.
+ *
+ * Calls a function for each registered omap_hwmod to check
+ * pad wakeup statuses.
+ */
+static irqreturn_t omap_hwmod_mux_handle_irq(int irq, void *unused)
+{
+	omap_hwmod_for_each(_omap_hwmod_mux_handle_irq, NULL);
+	return IRQ_HANDLED;
+}
+
 /* Assumes the calling function takes care of locking */
 void omap_hwmod_mux(struct omap_hwmod_mux_info *hmux, u8 state)
 {
@@ -715,6 +792,7 @@ static void __init omap_mux_free_names(struct omap_mux *m)
 static int __init omap_mux_late_init(void)
 {
 	struct omap_mux_partition *partition;
+	int ret;
 
 	list_for_each_entry(partition, &mux_partitions, node) {
 		struct omap_mux_entry *e, *tmp;
@@ -735,6 +813,13 @@ static int __init omap_mux_late_init(void)
 		}
 	}
 
+	ret = request_irq(omap_prcm_event_to_irq("io"),
+		omap_hwmod_mux_handle_irq, IRQF_SHARED | IRQF_NO_SUSPEND,
+			"hwmod_io", omap_mux_late_init);
+
+	if (ret)
+		pr_warning("mux: Failed to setup hwmod io irq %d\n", ret);
+
 	omap_mux_dbg_init();
 
 	return 0;
diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
index f673f808725..ee9416bcc3e 100644
--- a/arch/arm/mach-omap2/omap_hwmod.c
+++ b/arch/arm/mach-omap2/omap_hwmod.c
@@ -136,6 +136,7 @@
 #include <linux/list.h>
 #include <linux/mutex.h>
 #include <linux/spinlock.h>
+#include <linux/slab.h>
 
 #include "common.h"
 #include <plat/cpu.h>
@@ -381,6 +382,51 @@ static int _set_module_autoidle(struct omap_hwmod *oh, u8 autoidle,
 }
 
 /**
+ * _set_idle_ioring_wakeup - enable/disable IO pad wakeup on hwmod idle for mux
+ * @oh: struct omap_hwmod *
+ * @set_wake: bool value indicating to set (true) or clear (false) wakeup enable
+ *
+ * Set or clear the I/O pad wakeup flag in the mux entries for the
+ * hwmod @oh.  This function changes the @oh->mux->pads_dynamic array
+ * in memory.  If the hwmod is currently idled, and the new idle
+ * values don't match the previous ones, this function will also
+ * update the SCM PADCTRL registers.  Otherwise, if the hwmod is not
+ * currently idled, this function won't touch the hardware: the new
+ * mux settings are written to the SCM PADCTRL registers when the
+ * hwmod is idled.  No return value.
+ */
+static void _set_idle_ioring_wakeup(struct omap_hwmod *oh, bool set_wake)
+{
+	struct omap_device_pad *pad;
+	bool change = false;
+	u16 prev_idle;
+	int j;
+
+	if (!oh->mux || !oh->mux->enabled)
+		return;
+
+	for (j = 0; j < oh->mux->nr_pads_dynamic; j++) {
+		pad = oh->mux->pads_dynamic[j];
+
+		if (!(pad->flags & OMAP_DEVICE_PAD_WAKEUP))
+			continue;
+
+		prev_idle = pad->idle;
+
+		if (set_wake)
+			pad->idle |= OMAP_WAKEUP_EN;
+		else
+			pad->idle &= ~OMAP_WAKEUP_EN;
+
+		if (prev_idle != pad->idle)
+			change = true;
+	}
+
+	if (change && oh->_state == _HWMOD_STATE_IDLE)
+		omap_hwmod_mux(oh->mux, _HWMOD_STATE_IDLE);
+}
+
+/**
  * _enable_wakeup: set OCP_SYSCONFIG.ENAWAKEUP bit in the hardware
  * @oh: struct omap_hwmod *
  *
@@ -2437,6 +2483,7 @@ int omap_hwmod_enable_wakeup(struct omap_hwmod *oh)
 	v = oh->_sysc_cache;
 	_enable_wakeup(oh, &v);
 	_write_sysconfig(v, oh);
+	_set_idle_ioring_wakeup(oh, true);
 	spin_unlock_irqrestore(&oh->_lock, flags);
 
 	return 0;
@@ -2467,6 +2514,7 @@ int omap_hwmod_disable_wakeup(struct omap_hwmod *oh)
 	v = oh->_sysc_cache;
 	_disable_wakeup(oh, &v);
 	_write_sysconfig(v, oh);
+	_set_idle_ioring_wakeup(oh, false);
 	spin_unlock_irqrestore(&oh->_lock, flags);
 
 	return 0;
@@ -2683,3 +2731,57 @@ int omap_hwmod_no_setup_reset(struct omap_hwmod *oh)
 
 	return 0;
 }
+
+/**
+ * omap_hwmod_pad_route_irq - route an I/O pad wakeup to a particular MPU IRQ
+ * @oh: struct omap_hwmod * containing hwmod mux entries
+ * @pad_idx: array index in oh->mux of the hwmod mux entry to route wakeup
+ * @irq_idx: the hwmod mpu_irqs array index of the IRQ to trigger on wakeup
+ *
+ * When an I/O pad wakeup arrives for the dynamic or wakeup hwmod mux
+ * entry number @pad_idx for the hwmod @oh, trigger the interrupt
+ * service routine for the hwmod's mpu_irqs array index @irq_idx.  If
+ * this function is not called for a given pad_idx, then the ISR
+ * associated with @oh's first MPU IRQ will be triggered when an I/O
+ * pad wakeup occurs on that pad.  Note that @pad_idx is the index of
+ * the _dynamic or wakeup_ entry: if there are other entries not
+ * marked with OMAP_DEVICE_PAD_WAKEUP or OMAP_DEVICE_PAD_REMUX, these
+ * entries are NOT COUNTED in the dynamic pad index.  This function
+ * must be called separately for each pad that requires its interrupt
+ * to be re-routed this way.  Returns -EINVAL if there is an argument
+ * problem or if @oh does not have hwmod mux entries or MPU IRQs;
+ * returns -ENOMEM if memory cannot be allocated; or 0 upon success.
+ *
+ * XXX This function interface is fragile.  Rather than using array
+ * indexes, which are subject to unpredictable change, it should be
+ * using hwmod IRQ names, and some other stable key for the hwmod mux
+ * pad records.
+ */
+int omap_hwmod_pad_route_irq(struct omap_hwmod *oh, int pad_idx, int irq_idx)
+{
+	int nr_irqs;
+
+	might_sleep();
+
+	if (!oh || !oh->mux || !oh->mpu_irqs || pad_idx < 0 ||
+	    pad_idx >= oh->mux->nr_pads_dynamic)
+		return -EINVAL;
+
+	/* Check the number of available mpu_irqs */
+	for (nr_irqs = 0; oh->mpu_irqs[nr_irqs].irq >= 0; nr_irqs++)
+		;
+
+	if (irq_idx >= nr_irqs)
+		return -EINVAL;
+
+	if (!oh->mux->irqs) {
+		/* XXX What frees this? */
+		oh->mux->irqs = kzalloc(sizeof(int) * oh->mux->nr_pads_dynamic,
+			GFP_KERNEL);
+		if (!oh->mux->irqs)
+			return -ENOMEM;
+	}
+	oh->mux->irqs[pad_idx] = irq_idx;
+
+	return 0;
+}
diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index fa637dfdda5..53b5b1a71e0 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -195,7 +195,7 @@ static void omap3_save_secure_ram_context(void)
  * that any peripheral wake-up events occurring while attempting to
  * clear the PM_WKST_x are detected and cleared.
  */
-static int prcm_clear_mod_irqs(s16 module, u8 regs)
+static int prcm_clear_mod_irqs(s16 module, u8 regs, u32 ignore_bits)
 {
 	u32 wkst, fclk, iclk, clken;
 	u16 wkst_off = (regs == 3) ? OMAP3430ES2_PM_WKST3 : PM_WKST1;
@@ -207,6 +207,7 @@ static int prcm_clear_mod_irqs(s16 module, u8 regs)
 
 	wkst = omap2_prm_read_mod_reg(module, wkst_off);
 	wkst &= omap2_prm_read_mod_reg(module, grpsel_off);
+	wkst &= ~ignore_bits;
 	if (wkst) {
 		iclk = omap2_cm_read_mod_reg(module, iclk_off);
 		fclk = omap2_cm_read_mod_reg(module, fclk_off);
@@ -222,6 +223,7 @@ static int prcm_clear_mod_irqs(s16 module, u8 regs)
 			omap2_cm_set_mod_reg_bits(clken, module, fclk_off);
 			omap2_prm_write_mod_reg(wkst, module, wkst_off);
 			wkst = omap2_prm_read_mod_reg(module, wkst_off);
+			wkst &= ~ignore_bits;
 			c++;
 		}
 		omap2_cm_write_mod_reg(iclk, module, iclk_off);
@@ -231,76 +233,35 @@ static int prcm_clear_mod_irqs(s16 module, u8 regs)
 	return c;
 }
 
-static int _prcm_int_handle_wakeup(void)
+static irqreturn_t _prcm_int_handle_io(int irq, void *unused)
 {
 	int c;
 
-	c = prcm_clear_mod_irqs(WKUP_MOD, 1);
-	c += prcm_clear_mod_irqs(CORE_MOD, 1);
-	c += prcm_clear_mod_irqs(OMAP3430_PER_MOD, 1);
-	if (omap_rev() > OMAP3430_REV_ES1_0) {
-		c += prcm_clear_mod_irqs(CORE_MOD, 3);
-		c += prcm_clear_mod_irqs(OMAP3430ES2_USBHOST_MOD, 1);
-	}
+	c = prcm_clear_mod_irqs(WKUP_MOD, 1,
+		~(OMAP3430_ST_IO_MASK | OMAP3430_ST_IO_CHAIN_MASK));
 
-	return c;
+	return c ? IRQ_HANDLED : IRQ_NONE;
 }
 
-/*
- * PRCM Interrupt Handler
- *
- * The PRM_IRQSTATUS_MPU register indicates if there are any pending
- * interrupts from the PRCM for the MPU. These bits must be cleared in
- * order to clear the PRCM interrupt. The PRCM interrupt handler is
- * implemented to simply clear the PRM_IRQSTATUS_MPU in order to clear
- * the PRCM interrupt. Please note that bit 0 of the PRM_IRQSTATUS_MPU
- * register indicates that a wake-up event is pending for the MPU and
- * this bit can only be cleared if the all the wake-up events latched
- * in the various PM_WKST_x registers have been cleared. The interrupt
- * handler is implemented using a do-while loop so that if a wake-up
- * event occurred during the processing of the prcm interrupt handler
- * (setting a bit in the corresponding PM_WKST_x register and thus
- * preventing us from clearing bit 0 of the PRM_IRQSTATUS_MPU register)
- * this would be handled.
- */
-static irqreturn_t prcm_interrupt_handler (int irq, void *dev_id)
+static irqreturn_t _prcm_int_handle_wakeup(int irq, void *unused)
 {
-	u32 irqenable_mpu, irqstatus_mpu;
-	int c = 0;
-
-	irqenable_mpu = omap2_prm_read_mod_reg(OCP_MOD,
-					 OMAP3_PRM_IRQENABLE_MPU_OFFSET);
-	irqstatus_mpu = omap2_prm_read_mod_reg(OCP_MOD,
-					 OMAP3_PRM_IRQSTATUS_MPU_OFFSET);
-	irqstatus_mpu &= irqenable_mpu;
-
-	do {
-		if (irqstatus_mpu & (OMAP3430_WKUP_ST_MASK |
-				     OMAP3430_IO_ST_MASK)) {
-			c = _prcm_int_handle_wakeup();
-
-			/*
-			 * Is the MPU PRCM interrupt handler racing with the
-			 * IVA2 PRCM interrupt handler ?
-			 */
-			WARN(c == 0, "prcm: WARNING: PRCM indicated MPU wakeup "
-			     "but no wakeup sources are marked\n");
-		} else {
-			/* XXX we need to expand our PRCM interrupt handler */
-			WARN(1, "prcm: WARNING: PRCM interrupt received, but "
-			     "no code to handle it (%08x)\n", irqstatus_mpu);
-		}
-
-		omap2_prm_write_mod_reg(irqstatus_mpu, OCP_MOD,
-					OMAP3_PRM_IRQSTATUS_MPU_OFFSET);
-
-		irqstatus_mpu = omap2_prm_read_mod_reg(OCP_MOD,
-					OMAP3_PRM_IRQSTATUS_MPU_OFFSET);
-		irqstatus_mpu &= irqenable_mpu;
+	int c;
 
-	} while (irqstatus_mpu);
+	/*
+	 * Clear all except ST_IO and ST_IO_CHAIN for wkup module,
+	 * these are handled in a separate handler to avoid acking
+	 * IO events before parsing in mux code
+	 */
+	c = prcm_clear_mod_irqs(WKUP_MOD, 1,
+		OMAP3430_ST_IO_MASK | OMAP3430_ST_IO_CHAIN_MASK);
+	c += prcm_clear_mod_irqs(CORE_MOD, 1, 0);
+	c += prcm_clear_mod_irqs(OMAP3430_PER_MOD, 1, 0);
+	if (omap_rev() > OMAP3430_REV_ES1_0) {
+		c += prcm_clear_mod_irqs(CORE_MOD, 3, 0);
+		c += prcm_clear_mod_irqs(OMAP3430ES2_USBHOST_MOD, 1, 0);
+	}
 
-	return IRQ_HANDLED;
+	return c ? IRQ_HANDLED : IRQ_NONE;
 }
 
 static void omap34xx_save_context(u32 *save)
@@ -581,6 +542,7 @@ static int omap3_pm_begin(suspend_state_t state)
 	disable_hlt();
 	suspend_state = state;
 	omap_uart_enable_irqs(0);
+	omap_prcm_irq_prepare();
 	return 0;
 }
 
@@ -592,10 +554,16 @@ static void omap3_pm_end(void)
 	return;
 }
 
+static void omap3_pm_finish(void)
+{
+	omap_prcm_irq_complete();
+}
+
 static const struct platform_suspend_ops omap_pm_ops = {
 	.begin		= omap3_pm_begin,
 	.end		= omap3_pm_end,
 	.enter		= omap3_pm_enter,
+	.finish		= omap3_pm_finish,
 	.valid		= suspend_valid_only_mem,
 };
 #endif /* CONFIG_SUSPEND */
@@ -701,10 +669,6 @@ static void __init prcm_setup_regs(void)
 			  OMAP3430_GRPSEL_GPT1_MASK |
 			  OMAP3430_GRPSEL_GPT12_MASK,
 			  WKUP_MOD, OMAP3430_PM_MPUGRPSEL);
-	/* For some reason IO doesn't generate wakeup event even if
-	 * it is selected to mpu wakeup goup */
-	omap2_prm_write_mod_reg(OMAP3430_IO_EN_MASK | OMAP3430_WKUP_EN_MASK,
-			  OCP_MOD, OMAP3_PRM_IRQENABLE_MPU_OFFSET);
 
 	/* Enable PM_WKEN to support DSS LPR */
 	omap2_prm_write_mod_reg(OMAP3430_PM_WKEN_DSS_EN_DSS_MASK,
@@ -881,12 +845,21 @@ static int __init omap3_pm_init(void)
 	 * supervised mode for powerdomains */
 	prcm_setup_regs();
 
-	ret = request_irq(INT_34XX_PRCM_MPU_IRQ,
-			  (irq_handler_t)prcm_interrupt_handler,
-			  IRQF_DISABLED, "prcm", NULL);
+	ret = request_irq(omap_prcm_event_to_irq("wkup"),
+		_prcm_int_handle_wakeup, IRQF_NO_SUSPEND, "pm_wkup", NULL);
+
+	if (ret) {
+		pr_err("pm: Failed to request pm_wkup irq\n");
+		goto err1;
+	}
+
+	/* IO interrupt is shared with mux code */
+	ret = request_irq(omap_prcm_event_to_irq("io"),
+		_prcm_int_handle_io, IRQF_SHARED | IRQF_NO_SUSPEND, "pm_io",
+		omap3_pm_init);
+
 	if (ret) {
-		printk(KERN_ERR "request_irq failed to register for 0x%x\n",
-		       INT_34XX_PRCM_MPU_IRQ);
+		pr_err("pm: Failed to request pm_io irq\n");
 		goto err1;
 	}
 
diff --git a/arch/arm/mach-omap2/prcm-common.h b/arch/arm/mach-omap2/prcm-common.h
index 0363dcb0ef9..0f69d8fc562 100644
--- a/arch/arm/mach-omap2/prcm-common.h
+++ b/arch/arm/mach-omap2/prcm-common.h
@@ -4,7 +4,7 @@
 /*
  * OMAP2/3 PRCM base and module definitions
  *
- * Copyright (C) 2007-2009 Texas Instruments, Inc.
+ * Copyright (C) 2007-2009, 2011 Texas Instruments, Inc.
  * Copyright (C) 2007-2009 Nokia Corporation
  *
  * Written by Paul Walmsley
@@ -408,6 +408,79 @@
 extern void __iomem *prm_base;
 extern void __iomem *cm_base;
 extern void __iomem *cm2_base;
+
+/**
+ * struct omap_prcm_irq - describes a PRCM interrupt bit
+ * @name: a short name describing the interrupt type, e.g. "wkup" or "io"
+ * @offset: the bit shift of the interrupt inside the IRQ{ENABLE,STATUS} regs
+ * @priority: should this interrupt be handled before @priority=false IRQs?
+ *
+ * Describes interrupt bits inside the PRM_IRQ{ENABLE,STATUS}_MPU* registers.
+ * On systems with multiple PRM MPU IRQ registers, the bitfields read from
+ * the registers are concatenated, so @offset could be > 31 on these systems -
+ * see omap_prm_irq_handler() for more details.  I/O ring interrupts should
+ * have @priority set to true.
+ */
+struct omap_prcm_irq {
+	const char *name;
+	unsigned int offset;
+	bool priority;
+};
+
+/**
+ * struct omap_prcm_irq_setup - PRCM interrupt controller details
+ * @ack: PRM register offset for the first PRM_IRQSTATUS_MPU register
+ * @mask: PRM register offset for the first PRM_IRQENABLE_MPU register
+ * @nr_regs: number of PRM_IRQ{STATUS,ENABLE}_MPU* registers
+ * @nr_irqs: number of entries in the @irqs array
+ * @irqs: ptr to an array of PRCM interrupt bits (see @nr_irqs)
+ * @irq: MPU IRQ asserted when a PRCM interrupt arrives
+ * @read_pending_irqs: fn ptr to determine if any PRCM IRQs are pending
+ * @ocp_barrier: fn ptr to force buffered PRM writes to complete
+ * @save_and_clear_irqen: fn ptr to save and clear IRQENABLE regs
+ * @restore_irqen: fn ptr to save and clear IRQENABLE regs
+ * @saved_mask: IRQENABLE regs are saved here during suspend
+ * @priority_mask: 1 bit per IRQ, set to 1 if omap_prcm_irq.priority = true
+ * @base_irq: base dynamic IRQ number, returned from irq_alloc_descs() in init
+ * @suspended: set to true after Linux suspend code has called our ->prepare()
+ * @suspend_save_flag: set to true after IRQ masks have been saved and disabled
+ *
+ * @saved_mask, @priority_mask, @base_irq, @suspended, and
+ * @suspend_save_flag are populated dynamically, and are not to be
+ * specified in static initializers.
+ */
+struct omap_prcm_irq_setup {
+	u16 ack;
+	u16 mask;
+	u8 nr_regs;
+	u8 nr_irqs;
+	const struct omap_prcm_irq *irqs;
+	int irq;
+	void (*read_pending_irqs)(unsigned long *events);
+	void (*ocp_barrier)(void);
+	void (*save_and_clear_irqen)(u32 *saved_mask);
+	void (*restore_irqen)(u32 *saved_mask);
+	u32 *saved_mask;
+	u32 *priority_mask;
+	int base_irq;
+	bool suspended;
+	bool suspend_save_flag;
+};
+
+/* OMAP_PRCM_IRQ: convenience macro for creating struct omap_prcm_irq records */
+#define OMAP_PRCM_IRQ(_name, _offset, _priority) {	\
+	.name = _name,					\
+	.offset = _offset,				\
+	.priority = _priority				\
+	}
+
+extern void omap_prcm_irq_cleanup(void);
+extern int omap_prcm_register_chain_handler(
+	struct omap_prcm_irq_setup *irq_setup);
+extern int omap_prcm_event_to_irq(const char *event);
+extern void omap_prcm_irq_prepare(void);
+extern void omap_prcm_irq_complete(void);
+
 # endif
 
 #endif
diff --git a/arch/arm/mach-omap2/prm2xxx_3xxx.c b/arch/arm/mach-omap2/prm2xxx_3xxx.c
index 9a08ba39732..c1c4d86a79a 100644
--- a/arch/arm/mach-omap2/prm2xxx_3xxx.c
+++ b/arch/arm/mach-omap2/prm2xxx_3xxx.c
@@ -1,7 +1,7 @@
 /*
  * OMAP2/3 PRM module functions
  *
- * Copyright (C) 2010 Texas Instruments, Inc.
+ * Copyright (C) 2010-2011 Texas Instruments, Inc.
  * Copyright (C) 2010 Nokia Corporation
  * Benoît Cousson
  * Paul Walmsley
@@ -27,6 +27,24 @@
 #include "prm-regbits-24xx.h"
 #include "prm-regbits-34xx.h"
 
+static const struct omap_prcm_irq omap3_prcm_irqs[] = {
+	OMAP_PRCM_IRQ("wkup",	0,	0),
+	OMAP_PRCM_IRQ("io",	9,	1),
+};
+
+static struct omap_prcm_irq_setup omap3_prcm_irq_setup = {
+	.ack			= OMAP3_PRM_IRQSTATUS_MPU_OFFSET,
+	.mask			= OMAP3_PRM_IRQENABLE_MPU_OFFSET,
+	.nr_regs		= 1,
+	.irqs			= omap3_prcm_irqs,
+	.nr_irqs		= ARRAY_SIZE(omap3_prcm_irqs),
+	.irq			= INT_34XX_PRCM_MPU_IRQ,
+	.read_pending_irqs	= &omap3xxx_prm_read_pending_irqs,
+	.ocp_barrier		= &omap3xxx_prm_ocp_barrier,
+	.save_and_clear_irqen	= &omap3xxx_prm_save_and_clear_irqen,
+	.restore_irqen		= &omap3xxx_prm_restore_irqen,
+};
+
 u32 omap2_prm_read_mod_reg(s16 module, u16 idx)
 {
 	return __raw_readl(prm_base + module + idx);
@@ -212,3 +230,80 @@ u32 omap3_prm_vcvp_rmw(u32 mask, u32 bits, u8 offset)
 {
 	return omap2_prm_rmw_mod_reg_bits(mask, bits, OMAP3430_GR_MOD, offset);
 }
+
+/**
+ * omap3xxx_prm_read_pending_irqs - read pending PRM MPU IRQs into @events
+ * @events: ptr to a u32, preallocated by caller
+ *
+ * Read PRM_IRQSTATUS_MPU bits, AND'ed with the currently-enabled PRM
+ * MPU IRQs, and store the result into the u32 pointed to by @events.
+ * No return value.
+ */
+void omap3xxx_prm_read_pending_irqs(unsigned long *events)
+{
+	u32 mask, st;
+
+	/* XXX Can the mask read be avoided (e.g., can it come from RAM?) */
+	mask = omap2_prm_read_mod_reg(OCP_MOD, OMAP3_PRM_IRQENABLE_MPU_OFFSET);
+	st = omap2_prm_read_mod_reg(OCP_MOD, OMAP3_PRM_IRQSTATUS_MPU_OFFSET);
+
+	events[0] = mask & st;
+}
+
+/**
+ * omap3xxx_prm_ocp_barrier - force buffered MPU writes to the PRM to complete
+ *
+ * Force any buffered writes to the PRM IP block to complete.  Needed
+ * by the PRM IRQ handler, which reads and writes directly to the IP
+ * block, to avoid race conditions after acknowledging or clearing IRQ
+ * bits.  No return value.
+ */
+void omap3xxx_prm_ocp_barrier(void)
+{
+	omap2_prm_read_mod_reg(OCP_MOD, OMAP3_PRM_REVISION_OFFSET);
+}
+
+/**
+ * omap3xxx_prm_save_and_clear_irqen - save/clear PRM_IRQENABLE_MPU reg
+ * @saved_mask: ptr to a u32 array to save IRQENABLE bits
+ *
+ * Save the PRM_IRQENABLE_MPU register to @saved_mask.  @saved_mask
+ * must be allocated by the caller.  Intended to be used in the PRM
+ * interrupt handler suspend callback.  The OCP barrier is needed to
+ * ensure the write to disable PRM interrupts reaches the PRM before
+ * returning; otherwise, spurious interrupts might occur.  No return
+ * value.
+ */
+void omap3xxx_prm_save_and_clear_irqen(u32 *saved_mask)
+{
+	saved_mask[0] = omap2_prm_read_mod_reg(OCP_MOD,
+					       OMAP3_PRM_IRQENABLE_MPU_OFFSET);
+	omap2_prm_write_mod_reg(0, OCP_MOD, OMAP3_PRM_IRQENABLE_MPU_OFFSET);
+
+	/* OCP barrier */
+	omap2_prm_read_mod_reg(OCP_MOD, OMAP3_PRM_REVISION_OFFSET);
+}
+
+/**
+ * omap3xxx_prm_restore_irqen - set PRM_IRQENABLE_MPU register from args
+ * @saved_mask: ptr to a u32 array of IRQENABLE bits saved previously
+ *
+ * Restore the PRM_IRQENABLE_MPU register from @saved_mask.  Intended
+ * to be used in the PRM interrupt handler resume callback to restore
+ * values saved by omap3xxx_prm_save_and_clear_irqen().  No OCP
+ * barrier should be needed here; any pending PRM interrupts will fire
+ * once the writes reach the PRM.  No return value.
+ */
+void omap3xxx_prm_restore_irqen(u32 *saved_mask)
+{
+	omap2_prm_write_mod_reg(saved_mask[0], OCP_MOD,
+				OMAP3_PRM_IRQENABLE_MPU_OFFSET);
+}
+
+static int __init omap3xxx_prcm_init(void)
+{
+	if (cpu_is_omap34xx())
+		return omap_prcm_register_chain_handler(&omap3_prcm_irq_setup);
+	return 0;
+}
+subsys_initcall(omap3xxx_prcm_init);
diff --git a/arch/arm/mach-omap2/prm2xxx_3xxx.h b/arch/arm/mach-omap2/prm2xxx_3xxx.h
index cef533df086..70ac2a19dc5 100644
--- a/arch/arm/mach-omap2/prm2xxx_3xxx.h
+++ b/arch/arm/mach-omap2/prm2xxx_3xxx.h
@@ -1,7 +1,7 @@
 /*
  * OMAP2/3 Power/Reset Management (PRM) register definitions
  *
- * Copyright (C) 2007-2009 Texas Instruments, Inc.
+ * Copyright (C) 2007-2009, 2011 Texas Instruments, Inc.
  * Copyright (C) 2008-2010 Nokia Corporation
  * Paul Walmsley
  *
@@ -314,6 +314,13 @@ void omap3_prm_vp_clear_txdone(u8 vp_id);
 extern u32 omap3_prm_vcvp_read(u8 offset);
 extern void omap3_prm_vcvp_write(u32 val, u8 offset);
 extern u32 omap3_prm_vcvp_rmw(u32 mask, u32 bits, u8 offset);
+
+/* PRM interrupt-related functions */
+extern void omap3xxx_prm_read_pending_irqs(unsigned long *events);
+extern void omap3xxx_prm_ocp_barrier(void);
+extern void omap3xxx_prm_save_and_clear_irqen(u32 *saved_mask);
+extern void omap3xxx_prm_restore_irqen(u32 *saved_mask);
+
 #endif	/* CONFIG_ARCH_OMAP4 */
 
 #endif
diff --git a/arch/arm/mach-omap2/prm44xx.c b/arch/arm/mach-omap2/prm44xx.c
index dd885eecf22..33dd655e6aa 100644
--- a/arch/arm/mach-omap2/prm44xx.c
+++ b/arch/arm/mach-omap2/prm44xx.c
@@ -27,6 +27,24 @@
 #include "prcm44xx.h"
 #include "prminst44xx.h"
 
+static const struct omap_prcm_irq omap4_prcm_irqs[] = {
+	OMAP_PRCM_IRQ("wkup",   0,      0),
+	OMAP_PRCM_IRQ("io",     9,      1),
+};
+
+static struct omap_prcm_irq_setup omap4_prcm_irq_setup = {
+	.ack			= OMAP4_PRM_IRQSTATUS_MPU_OFFSET,
+	.mask			= OMAP4_PRM_IRQENABLE_MPU_OFFSET,
+	.nr_regs		= 2,
+	.irqs			= omap4_prcm_irqs,
+	.nr_irqs		= ARRAY_SIZE(omap4_prcm_irqs),
+	.irq			= OMAP44XX_IRQ_PRCM,
+	.read_pending_irqs	= &omap44xx_prm_read_pending_irqs,
+	.ocp_barrier		= &omap44xx_prm_ocp_barrier,
+	.save_and_clear_irqen	= &omap44xx_prm_save_and_clear_irqen,
+	.restore_irqen		= &omap44xx_prm_restore_irqen,
+};
+
 /* PRM low-level functions */
 
 /* Read a register in a CM/PRM instance in the PRM module */
@@ -121,3 +139,101 @@ u32 omap4_prm_vcvp_rmw(u32 mask, u32 bits, u8 offset)
 					       OMAP4430_PRM_DEVICE_INST,
 					       offset);
 }
+
+static inline u32 _read_pending_irq_reg(u16 irqen_offs, u16 irqst_offs)
+{
+	u32 mask, st;
+
+	/* XXX read mask from RAM? */
+	mask = omap4_prm_read_inst_reg(OMAP4430_PRM_DEVICE_INST, irqen_offs);
+	st = omap4_prm_read_inst_reg(OMAP4430_PRM_DEVICE_INST, irqst_offs);
+
+	return mask & st;
+}
+
+/**
+ * omap44xx_prm_read_pending_irqs - read pending PRM MPU IRQs into @events
+ * @events: ptr to two consecutive u32s, preallocated by caller
+ *
+ * Read PRM_IRQSTATUS_MPU* bits, AND'ed with the currently-enabled PRM
+ * MPU IRQs, and store the result into the two u32s pointed to by @events.
+ * No return value.
+ */
+void omap44xx_prm_read_pending_irqs(unsigned long *events)
+{
+	events[0] = _read_pending_irq_reg(OMAP4_PRM_IRQENABLE_MPU_OFFSET,
+					  OMAP4_PRM_IRQSTATUS_MPU_OFFSET);
+
+	events[1] = _read_pending_irq_reg(OMAP4_PRM_IRQENABLE_MPU_2_OFFSET,
+					  OMAP4_PRM_IRQSTATUS_MPU_2_OFFSET);
+}
+
+/**
+ * omap44xx_prm_ocp_barrier - force buffered MPU writes to the PRM to complete
+ *
+ * Force any buffered writes to the PRM IP block to complete.  Needed
+ * by the PRM IRQ handler, which reads and writes directly to the IP
+ * block, to avoid race conditions after acknowledging or clearing IRQ
+ * bits.  No return value.
+ */
+void omap44xx_prm_ocp_barrier(void)
+{
+	omap4_prm_read_inst_reg(OMAP4430_PRM_DEVICE_INST,
+				OMAP4_REVISION_PRM_OFFSET);
+}
+
+/**
+ * omap44xx_prm_save_and_clear_irqen - save/clear PRM_IRQENABLE_MPU* regs
+ * @saved_mask: ptr to a u32 array to save IRQENABLE bits
+ *
+ * Save the PRM_IRQENABLE_MPU and PRM_IRQENABLE_MPU_2 registers to
+ * @saved_mask.  @saved_mask must be allocated by the caller.
+ * Intended to be used in the PRM interrupt handler suspend callback.
+ * The OCP barrier is needed to ensure the write to disable PRM
+ * interrupts reaches the PRM before returning; otherwise, spurious
+ * interrupts might occur.  No return value.
+ */
+void omap44xx_prm_save_and_clear_irqen(u32 *saved_mask)
+{
+	saved_mask[0] =
+		omap4_prm_read_inst_reg(OMAP4430_PRM_DEVICE_INST,
+					OMAP4_PRM_IRQSTATUS_MPU_OFFSET);
+	saved_mask[1] =
+		omap4_prm_read_inst_reg(OMAP4430_PRM_DEVICE_INST,
+					OMAP4_PRM_IRQSTATUS_MPU_2_OFFSET);
+
+	omap4_prm_write_inst_reg(0, OMAP4430_PRM_DEVICE_INST,
+				 OMAP4_PRM_IRQENABLE_MPU_OFFSET);
+	omap4_prm_write_inst_reg(0, OMAP4430_PRM_DEVICE_INST,
+				 OMAP4_PRM_IRQENABLE_MPU_2_OFFSET);
+
+	/* OCP barrier */
+	omap4_prm_read_inst_reg(OMAP4430_PRM_DEVICE_INST,
+				OMAP4_REVISION_PRM_OFFSET);
+}
+
+/**
+ * omap44xx_prm_restore_irqen - set PRM_IRQENABLE_MPU* registers from args
+ * @saved_mask: ptr to a u32 array of IRQENABLE bits saved previously
+ *
+ * Restore the PRM_IRQENABLE_MPU and PRM_IRQENABLE_MPU_2 registers from
+ * @saved_mask.  Intended to be used in the PRM interrupt handler resume
+ * callback to restore values saved by omap44xx_prm_save_and_clear_irqen().
+ * No OCP barrier should be needed here; any pending PRM interrupts will fire
+ * once the writes reach the PRM.  No return value.
+ */
+void omap44xx_prm_restore_irqen(u32 *saved_mask)
+{
+	omap4_prm_write_inst_reg(saved_mask[0], OMAP4430_PRM_DEVICE_INST,
+				 OMAP4_PRM_IRQENABLE_MPU_OFFSET);
+	omap4_prm_write_inst_reg(saved_mask[1], OMAP4430_PRM_DEVICE_INST,
+				 OMAP4_PRM_IRQENABLE_MPU_2_OFFSET);
+}
+
+static int __init omap4xxx_prcm_init(void)
+{
+	if (cpu_is_omap44xx())
+		return omap_prcm_register_chain_handler(&omap4_prcm_irq_setup);
+	return 0;
+}
+subsys_initcall(omap4xxx_prcm_init);
diff --git a/arch/arm/mach-omap2/prm44xx.h b/arch/arm/mach-omap2/prm44xx.h
index 3d66ccd849d..7978092946d 100644
--- a/arch/arm/mach-omap2/prm44xx.h
+++ b/arch/arm/mach-omap2/prm44xx.h
@@ -1,7 +1,7 @@
 /*
  * OMAP44xx PRM instance offset macros
  *
- * Copyright (C) 2009-2010 Texas Instruments, Inc.
+ * Copyright (C) 2009-2011 Texas Instruments, Inc.
  * Copyright (C) 2009-2010 Nokia Corporation
  *
  * Paul Walmsley (paul@pwsan.com)
@@ -763,6 +763,12 @@ extern u32 omap4_prm_vcvp_read(u8 offset);
 extern void omap4_prm_vcvp_write(u32 val, u8 offset);
 extern u32 omap4_prm_vcvp_rmw(u32 mask, u32 bits, u8 offset);
 
+/* PRM interrupt-related functions */
+extern void omap44xx_prm_read_pending_irqs(unsigned long *events);
+extern void omap44xx_prm_ocp_barrier(void);
+extern void omap44xx_prm_save_and_clear_irqen(u32 *saved_mask);
+extern void omap44xx_prm_restore_irqen(u32 *saved_mask);
+
 # endif
 
 #endif
diff --git a/arch/arm/mach-omap2/prm_common.c b/arch/arm/mach-omap2/prm_common.c
new file mode 100644
index 00000000000..860118ab43e
--- /dev/null
+++ b/arch/arm/mach-omap2/prm_common.c
@@ -0,0 +1,320 @@
+/*
+ * OMAP2+ common Power & Reset Management (PRM) IP block functions
+ *
+ * Copyright (C) 2011 Texas Instruments, Inc.
+ * Tero Kristo <t-kristo@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ *
+ * For historical purposes, the API used to configure the PRM
+ * interrupt handler refers to it as the "PRCM interrupt."  The
+ * underlying registers are located in the PRM on OMAP3/4.
+ *
+ * XXX This code should eventually be moved to a PRM driver.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+
+#include <mach/system.h>
+#include <plat/common.h>
+#include <plat/prcm.h>
+#include <plat/irqs.h>
+
+#include "prm2xxx_3xxx.h"
+#include "prm44xx.h"
+
+/*
+ * OMAP_PRCM_MAX_NR_PENDING_REG: maximum number of PRM_IRQ*_MPU regs
+ * XXX this is technically not needed, since
+ * omap_prcm_register_chain_handler() could allocate this based on the
+ * actual amount of memory needed for the SoC
+ */
+#define OMAP_PRCM_MAX_NR_PENDING_REG		2
+
+/*
+ * prcm_irq_chips: an array of all of the "generic IRQ chips" in use
+ * by the PRCM interrupt handler code.  There will be one 'chip' per
+ * PRM_{IRQSTATUS,IRQENABLE}_MPU register pair.  (So OMAP3 will have
+ * one "chip" and OMAP4 will have two.)
+ */
+static struct irq_chip_generic **prcm_irq_chips;
+
+/*
+ * prcm_irq_setup: the PRCM IRQ parameters for the hardware the code
+ * is currently running on.  Defined and passed by initialization code
+ * that calls omap_prcm_register_chain_handler().
+ */
+static struct omap_prcm_irq_setup *prcm_irq_setup;
+
+/* Private functions */
+
+/*
+ * Move priority events from events to priority_events array
+ */
+static void omap_prcm_events_filter_priority(unsigned long *events,
+	unsigned long *priority_events)
+{
+	int i;
+
+	for (i = 0; i < prcm_irq_setup->nr_regs; i++) {
+		priority_events[i] =
+			events[i] & prcm_irq_setup->priority_mask[i];
+		events[i] ^= priority_events[i];
+	}
+}
+
+/*
+ * PRCM Interrupt Handler
+ *
+ * This is a common handler for the OMAP PRCM interrupts. Pending
+ * interrupts are detected by a call to prcm_pending_events and
+ * dispatched accordingly. Clearing of the wakeup events should be
+ * done by the SoC specific individual handlers.
+ */
+static void omap_prcm_irq_handler(unsigned int irq, struct irq_desc *desc)
+{
+	unsigned long pending[OMAP_PRCM_MAX_NR_PENDING_REG];
+	unsigned long priority_pending[OMAP_PRCM_MAX_NR_PENDING_REG];
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	unsigned int virtirq;
+	int nr_irqs = prcm_irq_setup->nr_regs * 32;
+
+	/*
+	 * If we are suspended, mask all interrupts from PRCM level,
+	 * this does not ack them, and they will be pending until we
+	 * re-enable the interrupts, at which point the
+	 * omap_prcm_irq_handler will be executed again.  The
+	 * _save_and_clear_irqen() function must ensure that the PRM
+	 * write to disable all IRQs has reached the PRM before
+	 * returning, or spurious PRCM interrupts may occur during
+	 * suspend.
+	 */
+	if (prcm_irq_setup->suspended) {
+		prcm_irq_setup->save_and_clear_irqen(prcm_irq_setup->saved_mask);
+		prcm_irq_setup->suspend_save_flag = true;
+	}
+
+	/*
+	 * Loop until all pending irqs are handled, since
+	 * generic_handle_irq() can cause new irqs to come
+	 */
+	while (!prcm_irq_setup->suspended) {
+		prcm_irq_setup->read_pending_irqs(pending);
+
+		/* No bit set, then all IRQs are handled */
+		if (find_first_bit(pending, nr_irqs) >= nr_irqs)
+			break;
+
+		omap_prcm_events_filter_priority(pending, priority_pending);
+
+		/*
+		 * Loop on all currently pending irqs so that new irqs
+		 * cannot starve previously pending irqs
+		 */
+
+		/* Serve priority events first */
+		for_each_set_bit(virtirq, priority_pending, nr_irqs)
+			generic_handle_irq(prcm_irq_setup->base_irq + virtirq);
+
+		/* Serve normal events next */
+		for_each_set_bit(virtirq, pending, nr_irqs)
+			generic_handle_irq(prcm_irq_setup->base_irq + virtirq);
+	}
+	if (chip->irq_ack)
+		chip->irq_ack(&desc->irq_data);
+	if (chip->irq_eoi)
+		chip->irq_eoi(&desc->irq_data);
+	chip->irq_unmask(&desc->irq_data);
+
+	prcm_irq_setup->ocp_barrier(); /* avoid spurious IRQs */
+}
+
+/* Public functions */
+
+/**
+ * omap_prcm_event_to_irq - given a PRCM event name, returns the
+ * corresponding IRQ on which the handler should be registered
+ * @name: name of the PRCM interrupt bit to look up - see struct omap_prcm_irq
+ *
+ * Returns the Linux internal IRQ ID corresponding to @name upon success,
+ * or -ENOENT upon failure.
+ */
+int omap_prcm_event_to_irq(const char *name)
+{
+	int i;
+
+	if (!prcm_irq_setup || !name)
+		return -ENOENT;
+
+	for (i = 0; i < prcm_irq_setup->nr_irqs; i++)
+		if (!strcmp(prcm_irq_setup->irqs[i].name, name))
+			return prcm_irq_setup->base_irq +
+				prcm_irq_setup->irqs[i].offset;
+
+	return -ENOENT;
+}
+
+/**
+ * omap_prcm_irq_cleanup - reverses memory allocated and other steps
+ * done by omap_prcm_register_chain_handler()
+ *
+ * No return value.
+ */
+void omap_prcm_irq_cleanup(void)
+{
+	int i;
+
+	if (!prcm_irq_setup) {
+		pr_err("PRCM: IRQ handler not initialized; cannot cleanup\n");
+		return;
+	}
+
+	if (prcm_irq_chips) {
+		for (i = 0; i < prcm_irq_setup->nr_regs; i++) {
+			if (prcm_irq_chips[i])
+				irq_remove_generic_chip(prcm_irq_chips[i],
+					0xffffffff, 0, 0);
+			prcm_irq_chips[i] = NULL;
+		}
+		kfree(prcm_irq_chips);
+		prcm_irq_chips = NULL;
+	}
+
+	kfree(prcm_irq_setup->saved_mask);
+	prcm_irq_setup->saved_mask = NULL;
+
+	kfree(prcm_irq_setup->priority_mask);
+	prcm_irq_setup->priority_mask = NULL;
+
+	irq_set_chained_handler(prcm_irq_setup->irq, NULL);
+
+	if (prcm_irq_setup->base_irq > 0)
+		irq_free_descs(prcm_irq_setup->base_irq,
+			prcm_irq_setup->nr_regs * 32);
+	prcm_irq_setup->base_irq = 0;
+}
+
+void omap_prcm_irq_prepare(void)
+{
+	prcm_irq_setup->suspended = true;
+}
+
+void omap_prcm_irq_complete(void)
+{
+	prcm_irq_setup->suspended = false;
+
+	/* If we have not saved the masks, do not attempt to restore */
+	if (!prcm_irq_setup->suspend_save_flag)
+		return;
+
+	prcm_irq_setup->suspend_save_flag = false;
+
+	/*
+	 * Re-enable all masked PRCM irq sources, this causes the PRCM
+	 * interrupt to fire immediately if the events were masked
+	 * previously in the chain handler
+	 */
+	prcm_irq_setup->restore_irqen(prcm_irq_setup->saved_mask);
+}
+
+/**
+ * omap_prcm_register_chain_handler - initializes the prcm chained interrupt
+ * handler based on provided parameters
+ * @irq_setup: hardware data about the underlying PRM/PRCM
+ *
+ * Set up the PRCM chained interrupt handler on the PRCM IRQ.  Sets up
+ * one generic IRQ chip per PRM interrupt status/enable register pair.
+ * Returns 0 upon success, -EINVAL if called twice or if invalid
+ * arguments are passed, or -ENOMEM on any other error.
+ */
+int omap_prcm_register_chain_handler(struct omap_prcm_irq_setup *irq_setup)
+{
+	int nr_regs = irq_setup->nr_regs;
+	u32 mask[OMAP_PRCM_MAX_NR_PENDING_REG];
+	int offset, i;
+	struct irq_chip_generic *gc;
+	struct irq_chip_type *ct;
+
+	if (!irq_setup)
+		return -EINVAL;
+
+	if (prcm_irq_setup) {
+		pr_err("PRCM: already initialized; won't reinitialize\n");
+		return -EINVAL;
+	}
+
+	if (nr_regs > OMAP_PRCM_MAX_NR_PENDING_REG) {
+		pr_err("PRCM: nr_regs too large\n");
+		return -EINVAL;
+	}
+
+	prcm_irq_setup = irq_setup;
+
+	prcm_irq_chips = kzalloc(sizeof(void *) * nr_regs, GFP_KERNEL);
+	prcm_irq_setup->saved_mask = kzalloc(sizeof(u32) * nr_regs, GFP_KERNEL);
+	prcm_irq_setup->priority_mask = kzalloc(sizeof(u32) * nr_regs,
+		GFP_KERNEL);
+
+	if (!prcm_irq_chips || !prcm_irq_setup->saved_mask ||
+	    !prcm_irq_setup->priority_mask) {
+		pr_err("PRCM: kzalloc failed\n");
+		goto err;
+	}
+
+	memset(mask, 0, sizeof(mask));
+
+	for (i = 0; i < irq_setup->nr_irqs; i++) {
+		offset = irq_setup->irqs[i].offset;
+		mask[offset >> 5] |= 1 << (offset & 0x1f);
+		if (irq_setup->irqs[i].priority)
+			irq_setup->priority_mask[offset >> 5] |=
+				1 << (offset & 0x1f);
+	}
+
+	irq_set_chained_handler(irq_setup->irq, omap_prcm_irq_handler);
+
+	irq_setup->base_irq = irq_alloc_descs(-1, 0, irq_setup->nr_regs * 32,
+		0);
+
+	if (irq_setup->base_irq < 0) {
+		pr_err("PRCM: failed to allocate irq descs: %d\n",
+			irq_setup->base_irq);
+		goto err;
+	}
+
+	for (i = 0; i <= irq_setup->nr_regs; i++) {
+		gc = irq_alloc_generic_chip("PRCM", 1,
+			irq_setup->base_irq + i * 32, prm_base,
+			handle_level_irq);
+
+		if (!gc) {
+			pr_err("PRCM: failed to allocate generic chip\n");
+			goto err;
+		}
+		ct = gc->chip_types;
+		ct->chip.irq_ack = irq_gc_ack_set_bit;
+		ct->chip.irq_mask = irq_gc_mask_clr_bit;
+		ct->chip.irq_unmask = irq_gc_mask_set_bit;
+
+		ct->regs.ack = irq_setup->ack + i * 4;
+		ct->regs.mask = irq_setup->mask + i * 4;
+
+		irq_setup_generic_chip(gc, mask[i], 0, IRQ_NOREQUEST, 0);
+		prcm_irq_chips[i] = gc;
+	}
+
+	return 0;
+
+err:
+	omap_prcm_irq_cleanup();
+	return -ENOMEM;
+}