arch/arm/mach-omap2/prm2xxx_3xxx.c - kernel/msm-4.19 - Gitiles

 /*
  * OMAP2/3 PRM module functions
  *
  * Copyright (C) 2010-2011 Texas Instruments, Inc.
  * Copyright (C) 2010 Nokia Corporation
  * Benoît Cousson
  * 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/errno.h>
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/irq.h>

 #include "common.h"
 #include <plat/cpu.h>
 #include <plat/prcm.h>

 #include "vp.h"

 #include "prm2xxx_3xxx.h"
 #include "cm2xxx_3xxx.h"
 #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			= 11 + OMAP_INTC_START,
 	.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);
 }

 void omap2_prm_write_mod_reg(u32 val, s16 module, u16 idx)
 {
 	__raw_writel(val, prm_base + module + idx);
 }

 /* Read-modify-write a register in a PRM module. Caller must lock */
 u32 omap2_prm_rmw_mod_reg_bits(u32 mask, u32 bits, s16 module, s16 idx)
 {
 	u32 v;

 	v = omap2_prm_read_mod_reg(module, idx);
 	v &= ~mask;
 	v |= bits;
 	omap2_prm_write_mod_reg(v, module, idx);

 	return v;
 }

 /* Read a PRM register, AND it, and shift the result down to bit 0 */
 u32 omap2_prm_read_mod_bits_shift(s16 domain, s16 idx, u32 mask)
 {
 	u32 v;

 	v = omap2_prm_read_mod_reg(domain, idx);
 	v &= mask;
 	v >>= __ffs(mask);

 	return v;
 }

 u32 omap2_prm_set_mod_reg_bits(u32 bits, s16 module, s16 idx)
 {
 	return omap2_prm_rmw_mod_reg_bits(bits, bits, module, idx);
 }

 u32 omap2_prm_clear_mod_reg_bits(u32 bits, s16 module, s16 idx)
 {
 	return omap2_prm_rmw_mod_reg_bits(bits, 0x0, module, idx);
 }


 /**
  * omap2_prm_is_hardreset_asserted - read the HW reset line state of
  * submodules contained in the hwmod module
  * @prm_mod: PRM submodule base (e.g. CORE_MOD)
  * @shift: register bit shift corresponding to the reset line to check
  *
  * Returns 1 if the (sub)module hardreset line is currently asserted,
  * 0 if the (sub)module hardreset line is not currently asserted, or
  * -EINVAL if called while running on a non-OMAP2/3 chip.
  */
 int omap2_prm_is_hardreset_asserted(s16 prm_mod, u8 shift)
 {
 	if (!(cpu_is_omap24xx() || cpu_is_omap34xx()))
 		return -EINVAL;

 	return omap2_prm_read_mod_bits_shift(prm_mod, OMAP2_RM_RSTCTRL,
 				       (1 << shift));
 }

 /**
  * omap2_prm_assert_hardreset - assert the HW reset line of a submodule
  * @prm_mod: PRM submodule base (e.g. CORE_MOD)
  * @shift: register bit shift corresponding to the reset line to assert
  *
  * Some IPs like dsp or iva contain processors that require an HW
  * reset line to be asserted / deasserted in order to fully enable the
  * IP.  These modules may have multiple hard-reset lines that reset
  * different 'submodules' inside the IP block.  This function will
  * place the submodule into reset.  Returns 0 upon success or -EINVAL
  * upon an argument error.
  */
 int omap2_prm_assert_hardreset(s16 prm_mod, u8 shift)
 {
 	u32 mask;

 	if (!(cpu_is_omap24xx() || cpu_is_omap34xx()))
 		return -EINVAL;

 	mask = 1 << shift;
 	omap2_prm_rmw_mod_reg_bits(mask, mask, prm_mod, OMAP2_RM_RSTCTRL);

 	return 0;
 }

 /**
  * omap2_prm_deassert_hardreset - deassert a submodule hardreset line and wait
  * @prm_mod: PRM submodule base (e.g. CORE_MOD)
  * @rst_shift: register bit shift corresponding to the reset line to deassert
  * @st_shift: register bit shift for the status of the deasserted submodule
  *
  * Some IPs like dsp or iva contain processors that require an HW
  * reset line to be asserted / deasserted in order to fully enable the
  * IP.  These modules may have multiple hard-reset lines that reset
  * different 'submodules' inside the IP block.  This function will
  * take the submodule out of reset and wait until the PRCM indicates
  * that the reset has completed before returning.  Returns 0 upon success or
  * -EINVAL upon an argument error, -EEXIST if the submodule was already out
  * of reset, or -EBUSY if the submodule did not exit reset promptly.
  */
 int omap2_prm_deassert_hardreset(s16 prm_mod, u8 rst_shift, u8 st_shift)
 {
 	u32 rst, st;
 	int c;

 	if (!(cpu_is_omap24xx() || cpu_is_omap34xx()))
 		return -EINVAL;

 	rst = 1 << rst_shift;
 	st = 1 << st_shift;

 	/* Check the current status to avoid de-asserting the line twice */
 	if (omap2_prm_read_mod_bits_shift(prm_mod, OMAP2_RM_RSTCTRL, rst) == 0)
 		return -EEXIST;

 	/* Clear the reset status by writing 1 to the status bit */
 	omap2_prm_rmw_mod_reg_bits(0xffffffff, st, prm_mod, OMAP2_RM_RSTST);
 	/* de-assert the reset control line */
 	omap2_prm_rmw_mod_reg_bits(rst, 0, prm_mod, OMAP2_RM_RSTCTRL);
 	/* wait the status to be set */
 	omap_test_timeout(omap2_prm_read_mod_bits_shift(prm_mod, OMAP2_RM_RSTST,
 						  st),
 			  MAX_MODULE_HARDRESET_WAIT, c);

 	return (c == MAX_MODULE_HARDRESET_WAIT) ? -EBUSY : 0;
 }

 /* PRM VP */

 /*
  * struct omap3_vp - OMAP3 VP register access description.
  * @tranxdone_status: VP_TRANXDONE_ST bitmask in PRM_IRQSTATUS_MPU reg
  */
 struct omap3_vp {
 	u32 tranxdone_status;
 };

 static struct omap3_vp omap3_vp[] = {
 	[OMAP3_VP_VDD_MPU_ID] = {
 		.tranxdone_status = OMAP3430_VP1_TRANXDONE_ST_MASK,
 	},
 	[OMAP3_VP_VDD_CORE_ID] = {
 		.tranxdone_status = OMAP3430_VP2_TRANXDONE_ST_MASK,
 	},
 };

 #define MAX_VP_ID ARRAY_SIZE(omap3_vp);

 u32 omap3_prm_vp_check_txdone(u8 vp_id)
 {
 	struct omap3_vp *vp = &omap3_vp[vp_id];
 	u32 irqstatus;

 	irqstatus = omap2_prm_read_mod_reg(OCP_MOD,
 					   OMAP3_PRM_IRQSTATUS_MPU_OFFSET);
 	return irqstatus & vp->tranxdone_status;
 }

 void omap3_prm_vp_clear_txdone(u8 vp_id)
 {
 	struct omap3_vp *vp = &omap3_vp[vp_id];

 	omap2_prm_write_mod_reg(vp->tranxdone_status,
 				OCP_MOD, OMAP3_PRM_IRQSTATUS_MPU_OFFSET);
 }

 u32 omap3_prm_vcvp_read(u8 offset)
 {
 	return omap2_prm_read_mod_reg(OMAP3430_GR_MOD, offset);
 }

 void omap3_prm_vcvp_write(u32 val, u8 offset)
 {
 	omap2_prm_write_mod_reg(val, OMAP3430_GR_MOD, offset);
 }

 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);
 }

 /**
  * omap3xxx_prm_reconfigure_io_chain - clear latches and reconfigure I/O chain
  *
  * Clear any previously-latched I/O wakeup events and ensure that the
  * I/O wakeup gates are aligned with the current mux settings.  Works
  * by asserting WUCLKIN, waiting for WUCLKOUT to be asserted, and then
  * deasserting WUCLKIN and clearing the ST_IO_CHAIN WKST bit.  No
  * return value.
  */
 void omap3xxx_prm_reconfigure_io_chain(void)
 {
 	int i = 0;

 	omap2_prm_set_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
 				   PM_WKEN);

 	omap_test_timeout(omap2_prm_read_mod_reg(WKUP_MOD, PM_WKST) &
 			  OMAP3430_ST_IO_CHAIN_MASK,
 			  MAX_IOPAD_LATCH_TIME, i);
 	if (i == MAX_IOPAD_LATCH_TIME)
 		pr_warn("PRM: I/O chain clock line assertion timed out\n");

 	omap2_prm_clear_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
 				     PM_WKEN);

 	omap2_prm_set_mod_reg_bits(OMAP3430_ST_IO_CHAIN_MASK, WKUP_MOD,
 				   PM_WKST);

 	omap2_prm_read_mod_reg(WKUP_MOD, PM_WKST);
 }

 /**
  * omap3xxx_prm_enable_io_wakeup - enable wakeup events from I/O wakeup latches
  *
  * Activates the I/O wakeup event latches and allows events logged by
  * those latches to signal a wakeup event to the PRCM.  For I/O
  * wakeups to occur, WAKEUPENABLE bits must be set in the pad mux
  * registers, and omap3xxx_prm_reconfigure_io_chain() must be called.
  * No return value.
  */
 static void __init omap3xxx_prm_enable_io_wakeup(void)
 {
 	if (omap3_has_io_wakeup())
 		omap2_prm_set_mod_reg_bits(OMAP3430_EN_IO_MASK, WKUP_MOD,
 					   PM_WKEN);
 }

 static int __init omap3xxx_prcm_init(void)
 {
 	int ret = 0;

 	if (cpu_is_omap34xx()) {
 		omap3xxx_prm_enable_io_wakeup();
 		ret = omap_prcm_register_chain_handler(&omap3_prcm_irq_setup);
 		if (!ret)
 			irq_set_status_flags(omap_prcm_event_to_irq("io"),
 					     IRQ_NOAUTOEN);
 	}

 	return ret;
 }
 subsys_initcall(omap3xxx_prcm_init);
	/*
	* OMAP2/3 PRM module functions
	*
	* Copyright (C) 2010-2011 Texas Instruments, Inc.
	* Copyright (C) 2010 Nokia Corporation
	* Benoît Cousson
	* 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/errno.h>
	#include <linux/err.h>
	#include <linux/io.h>
	#include <linux/irq.h>

	#include "common.h"
	#include <plat/cpu.h>
	#include <plat/prcm.h>

	#include "vp.h"

	#include "prm2xxx_3xxx.h"
	#include "cm2xxx_3xxx.h"
	#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 = 11 + OMAP_INTC_START,
	.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);
	}

	void omap2_prm_write_mod_reg(u32 val, s16 module, u16 idx)
	{
	__raw_writel(val, prm_base + module + idx);
	}

	/* Read-modify-write a register in a PRM module. Caller must lock */
	u32 omap2_prm_rmw_mod_reg_bits(u32 mask, u32 bits, s16 module, s16 idx)
	{
	u32 v;

	v = omap2_prm_read_mod_reg(module, idx);
	v &= ~mask;
	v \|= bits;
	omap2_prm_write_mod_reg(v, module, idx);

	return v;
	}

	/* Read a PRM register, AND it, and shift the result down to bit 0 */
	u32 omap2_prm_read_mod_bits_shift(s16 domain, s16 idx, u32 mask)
	{
	u32 v;

	v = omap2_prm_read_mod_reg(domain, idx);
	v &= mask;
	v >>= __ffs(mask);

	return v;
	}

	u32 omap2_prm_set_mod_reg_bits(u32 bits, s16 module, s16 idx)
	{
	return omap2_prm_rmw_mod_reg_bits(bits, bits, module, idx);
	}

	u32 omap2_prm_clear_mod_reg_bits(u32 bits, s16 module, s16 idx)
	{
	return omap2_prm_rmw_mod_reg_bits(bits, 0x0, module, idx);
	}


	/**
	* omap2_prm_is_hardreset_asserted - read the HW reset line state of
	* submodules contained in the hwmod module
	* @prm_mod: PRM submodule base (e.g. CORE_MOD)
	* @shift: register bit shift corresponding to the reset line to check
	*
	* Returns 1 if the (sub)module hardreset line is currently asserted,
	* 0 if the (sub)module hardreset line is not currently asserted, or
	* -EINVAL if called while running on a non-OMAP2/3 chip.
	*/
	int omap2_prm_is_hardreset_asserted(s16 prm_mod, u8 shift)
	{
	if (!(cpu_is_omap24xx() \|\| cpu_is_omap34xx()))
	return -EINVAL;

	return omap2_prm_read_mod_bits_shift(prm_mod, OMAP2_RM_RSTCTRL,
	(1 << shift));
	}

	/**
	* omap2_prm_assert_hardreset - assert the HW reset line of a submodule
	* @prm_mod: PRM submodule base (e.g. CORE_MOD)
	* @shift: register bit shift corresponding to the reset line to assert
	*
	* Some IPs like dsp or iva contain processors that require an HW
	* reset line to be asserted / deasserted in order to fully enable the
	* IP. These modules may have multiple hard-reset lines that reset
	* different 'submodules' inside the IP block. This function will
	* place the submodule into reset. Returns 0 upon success or -EINVAL
	* upon an argument error.
	*/
	int omap2_prm_assert_hardreset(s16 prm_mod, u8 shift)
	{
	u32 mask;

	if (!(cpu_is_omap24xx() \|\| cpu_is_omap34xx()))
	return -EINVAL;

	mask = 1 << shift;
	omap2_prm_rmw_mod_reg_bits(mask, mask, prm_mod, OMAP2_RM_RSTCTRL);

	return 0;
	}

	/**
	* omap2_prm_deassert_hardreset - deassert a submodule hardreset line and wait
	* @prm_mod: PRM submodule base (e.g. CORE_MOD)
	* @rst_shift: register bit shift corresponding to the reset line to deassert
	* @st_shift: register bit shift for the status of the deasserted submodule
	*
	* Some IPs like dsp or iva contain processors that require an HW
	* reset line to be asserted / deasserted in order to fully enable the
	* IP. These modules may have multiple hard-reset lines that reset
	* different 'submodules' inside the IP block. This function will
	* take the submodule out of reset and wait until the PRCM indicates
	* that the reset has completed before returning. Returns 0 upon success or
	* -EINVAL upon an argument error, -EEXIST if the submodule was already out
	* of reset, or -EBUSY if the submodule did not exit reset promptly.
	*/
	int omap2_prm_deassert_hardreset(s16 prm_mod, u8 rst_shift, u8 st_shift)
	{
	u32 rst, st;
	int c;

	if (!(cpu_is_omap24xx() \|\| cpu_is_omap34xx()))
	return -EINVAL;

	rst = 1 << rst_shift;
	st = 1 << st_shift;

	/* Check the current status to avoid de-asserting the line twice */
	if (omap2_prm_read_mod_bits_shift(prm_mod, OMAP2_RM_RSTCTRL, rst) == 0)
	return -EEXIST;

	/* Clear the reset status by writing 1 to the status bit */
	omap2_prm_rmw_mod_reg_bits(0xffffffff, st, prm_mod, OMAP2_RM_RSTST);
	/* de-assert the reset control line */
	omap2_prm_rmw_mod_reg_bits(rst, 0, prm_mod, OMAP2_RM_RSTCTRL);
	/* wait the status to be set */
	omap_test_timeout(omap2_prm_read_mod_bits_shift(prm_mod, OMAP2_RM_RSTST,
	st),
	MAX_MODULE_HARDRESET_WAIT, c);

	return (c == MAX_MODULE_HARDRESET_WAIT) ? -EBUSY : 0;
	}

	/* PRM VP */

	/*
	* struct omap3_vp - OMAP3 VP register access description.
	* @tranxdone_status: VP_TRANXDONE_ST bitmask in PRM_IRQSTATUS_MPU reg
	*/
	struct omap3_vp {
	u32 tranxdone_status;
	};

	static struct omap3_vp omap3_vp[] = {
	[OMAP3_VP_VDD_MPU_ID] = {
	.tranxdone_status = OMAP3430_VP1_TRANXDONE_ST_MASK,
	},
	[OMAP3_VP_VDD_CORE_ID] = {
	.tranxdone_status = OMAP3430_VP2_TRANXDONE_ST_MASK,
	},
	};

	#define MAX_VP_ID ARRAY_SIZE(omap3_vp);

	u32 omap3_prm_vp_check_txdone(u8 vp_id)
	{
	struct omap3_vp *vp = &omap3_vp[vp_id];
	u32 irqstatus;

	irqstatus = omap2_prm_read_mod_reg(OCP_MOD,
	OMAP3_PRM_IRQSTATUS_MPU_OFFSET);
	return irqstatus & vp->tranxdone_status;
	}

	void omap3_prm_vp_clear_txdone(u8 vp_id)
	{
	struct omap3_vp *vp = &omap3_vp[vp_id];

	omap2_prm_write_mod_reg(vp->tranxdone_status,
	OCP_MOD, OMAP3_PRM_IRQSTATUS_MPU_OFFSET);
	}

	u32 omap3_prm_vcvp_read(u8 offset)
	{
	return omap2_prm_read_mod_reg(OMAP3430_GR_MOD, offset);
	}

	void omap3_prm_vcvp_write(u32 val, u8 offset)
	{
	omap2_prm_write_mod_reg(val, OMAP3430_GR_MOD, offset);
	}

	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);
	}

	/**
	* omap3xxx_prm_reconfigure_io_chain - clear latches and reconfigure I/O chain
	*
	* Clear any previously-latched I/O wakeup events and ensure that the
	* I/O wakeup gates are aligned with the current mux settings. Works
	* by asserting WUCLKIN, waiting for WUCLKOUT to be asserted, and then
	* deasserting WUCLKIN and clearing the ST_IO_CHAIN WKST bit. No
	* return value.
	*/
	void omap3xxx_prm_reconfigure_io_chain(void)
	{
	int i = 0;

	omap2_prm_set_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
	PM_WKEN);

	omap_test_timeout(omap2_prm_read_mod_reg(WKUP_MOD, PM_WKST) &
	OMAP3430_ST_IO_CHAIN_MASK,
	MAX_IOPAD_LATCH_TIME, i);
	if (i == MAX_IOPAD_LATCH_TIME)
	pr_warn("PRM: I/O chain clock line assertion timed out\n");

	omap2_prm_clear_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
	PM_WKEN);

	omap2_prm_set_mod_reg_bits(OMAP3430_ST_IO_CHAIN_MASK, WKUP_MOD,
	PM_WKST);

	omap2_prm_read_mod_reg(WKUP_MOD, PM_WKST);
	}

	/**
	* omap3xxx_prm_enable_io_wakeup - enable wakeup events from I/O wakeup latches
	*
	* Activates the I/O wakeup event latches and allows events logged by
	* those latches to signal a wakeup event to the PRCM. For I/O
	* wakeups to occur, WAKEUPENABLE bits must be set in the pad mux
	* registers, and omap3xxx_prm_reconfigure_io_chain() must be called.
	* No return value.
	*/
	static void __init omap3xxx_prm_enable_io_wakeup(void)
	{
	if (omap3_has_io_wakeup())
	omap2_prm_set_mod_reg_bits(OMAP3430_EN_IO_MASK, WKUP_MOD,
	PM_WKEN);
	}

	static int __init omap3xxx_prcm_init(void)
	{
	int ret = 0;

	if (cpu_is_omap34xx()) {
	omap3xxx_prm_enable_io_wakeup();
	ret = omap_prcm_register_chain_handler(&omap3_prcm_irq_setup);
	if (!ret)
	irq_set_status_flags(omap_prcm_event_to_irq("io"),
	IRQ_NOAUTOEN);
	}

	return ret;
	}
	subsys_initcall(omap3xxx_prcm_init);