diff --git a/arch/arm/mach-omap2/Makefile b/arch/arm/mach-omap2/Makefile
index 8850a247bec9..59d730fa77e5 100644
--- a/arch/arm/mach-omap2/Makefile
+++ b/arch/arm/mach-omap2/Makefile
@@ -35,6 +35,11 @@ obj-$(CONFIG_ARCH_OMAP3)		+= pm34xx.o sleep34xx.o
 obj-$(CONFIG_PM_DEBUG)			+= pm-debug.o
 endif
 
+# PRCM
+obj-$(CONFIG_ARCH_OMAP2)		+= cm.o
+obj-$(CONFIG_ARCH_OMAP3)		+= cm.o
+obj-$(CONFIG_ARCH_OMAP4)		+= cm4xxx.o
+
 # Clock framework
 obj-$(CONFIG_ARCH_OMAP2)		+= clock24xx.o
 obj-$(CONFIG_ARCH_OMAP3)		+= clock34xx.o
diff --git a/arch/arm/mach-omap2/cm.c b/arch/arm/mach-omap2/cm.c
new file mode 100644
index 000000000000..8eb2dab8c7db
--- /dev/null
+++ b/arch/arm/mach-omap2/cm.c
@@ -0,0 +1,70 @@
+/*
+ * OMAP2/3 CM module functions
+ *
+ * Copyright (C) 2009 Nokia Corporation
+ * Paul Walmsley
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/list.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/io.h>
+
+#include <asm/atomic.h>
+
+#include "cm.h"
+#include "cm-regbits-24xx.h"
+#include "cm-regbits-34xx.h"
+
+/* MAX_MODULE_READY_TIME: max milliseconds for module to leave idle */
+#define MAX_MODULE_READY_TIME		20000
+
+static const u8 cm_idlest_offs[] = {
+	CM_IDLEST1, CM_IDLEST2, OMAP2430_CM_IDLEST3
+};
+
+/**
+ * omap2_cm_wait_idlest_ready - wait for a module to leave idle or standby
+ * @prcm_mod: PRCM module offset
+ * @idlest_id: CM_IDLESTx register ID (i.e., x = 1, 2, 3)
+ * @idlest_shift: shift of the bit in the CM_IDLEST* register to check
+ *
+ * XXX document
+ */
+int omap2_cm_wait_module_ready(s16 prcm_mod, u8 idlest_id, u8 idlest_shift)
+{
+	int ena = 0, i = 0;
+	u8 cm_idlest_reg;
+	u32 mask;
+
+	if (!idlest_id || (idlest_id > ARRAY_SIZE(cm_idlest_offs)))
+		return -EINVAL;
+
+	cm_idlest_reg = cm_idlest_offs[idlest_id - 1];
+
+	if (cpu_is_omap24xx())
+		ena = idlest_shift;
+	else if (cpu_is_omap34xx())
+		ena = 0;
+	else
+		BUG();
+
+	mask = 1 << idlest_shift;
+
+	/* XXX should be OMAP2 CM */
+	while (((cm_read_mod_reg(prcm_mod, cm_idlest_reg) & mask) != ena) &&
+	       (i++ < MAX_MODULE_READY_TIME))
+		udelay(1);
+
+	return (i < MAX_MODULE_READY_TIME) ? 0 : -EBUSY;
+}
+
diff --git a/arch/arm/mach-omap2/cm.h b/arch/arm/mach-omap2/cm.h
index 18d9a121aa7a..cfd0b726ba44 100644
--- a/arch/arm/mach-omap2/cm.h
+++ b/arch/arm/mach-omap2/cm.h
@@ -98,6 +98,10 @@ extern u32 cm_read_mod_reg(s16 module, u16 idx);
 extern void cm_write_mod_reg(u32 val, s16 module, u16 idx);
 extern u32 cm_rmw_mod_reg_bits(u32 mask, u32 bits, s16 module, s16 idx);
 
+extern int omap2_cm_wait_module_ready(s16 prcm_mod, u8 idlest_id,
+				      u8 idlest_shift);
+extern int omap4_cm_wait_module_ready(u32 prcm_mod, u8 prcm_dev_offs);
+
 static inline u32 cm_set_mod_reg_bits(u32 bits, s16 module, s16 idx)
 {
 	return cm_rmw_mod_reg_bits(bits, bits, module, idx);
diff --git a/arch/arm/mach-omap2/cm4xxx.c b/arch/arm/mach-omap2/cm4xxx.c
new file mode 100644
index 000000000000..e4ebd6d53135
--- /dev/null
+++ b/arch/arm/mach-omap2/cm4xxx.c
@@ -0,0 +1,68 @@
+/*
+ * OMAP4 CM module functions
+ *
+ * Copyright (C) 2009 Nokia Corporation
+ * Paul Walmsley
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/list.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/io.h>
+
+#include <asm/atomic.h>
+
+#include "cm.h"
+#include "cm-regbits-4xxx.h"
+
+/* XXX move this to cm.h */
+/* MAX_MODULE_READY_TIME: max milliseconds for module to leave idle */
+#define MAX_MODULE_READY_TIME			20000
+
+/*
+ * OMAP4_PRCM_CM_CLKCTRL_IDLEST_MASK: isolates the IDLEST field in the
+ * CM_CLKCTRL register.
+ */
+#define OMAP4_PRCM_CM_CLKCTRL_IDLEST_MASK	(0x2 << 16)
+
+/*
+ * OMAP4 prcm_mod u32 fields contain packed data: the CM ID in bit 16 and
+ * the PRCM module offset address (from the CM module base) in bits 15-0.
+ */
+#define OMAP4_PRCM_MOD_CM_ID_SHIFT		16
+#define OMAP4_PRCM_MOD_OFFS_MASK		0xffff
+
+/**
+ * omap4_cm_wait_idlest_ready - wait for a module to leave idle or standby
+ * @prcm_mod: PRCM module offset (XXX example)
+ * @prcm_dev_offs: PRCM device offset (e.g. MCASP XXX example)
+ *
+ * XXX document
+ */
+int omap4_cm_wait_idlest_ready(u32 prcm_mod, u8 prcm_dev_offs)
+{
+	int i = 0;
+	u8 cm_id;
+	u16 prcm_mod_offs;
+	u32 mask = OMAP4_PRCM_CM_CLKCTRL_IDLEST_MASK;
+
+	cm_id = prcm_mod >> OMAP4_PRCM_MOD_CM_ID_SHIFT;
+	prcm_mod_offs = prcm_mod & OMAP4_PRCM_MOD_OFFS_MASK;
+
+	while (((omap4_cm_read_mod_reg(cm_id, prcm_mod_offs, prcm_dev_offs,
+				       OMAP4_CM_CLKCTRL_DREG) & mask) != 0) &&
+	       (i++ < MAX_MODULE_READY_TIME))
+		udelay(1);
+
+	return (i < MAX_MODULE_READY_TIME) ? 0 : -EBUSY;
+}
+