arch/arm/mach-omap2/sleep44xx.S - kernel/windcharger - Git at Google

 /*
  * OMAP44xx sleep code.
  *
  * Copyright (C) 2011 Texas Instruments, Inc.
  * 	Santosh Shilimkar <santosh.shilimkar@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.
  */

 #include <linux/linkage.h>
 #include <asm/system.h>
 #include <asm/smp_scu.h>
 #include <asm/memory.h>
 #include <asm/hardware/cache-l2x0.h>

 #include <plat/omap44xx.h>
 #include <mach/omap-secure.h>

 #include "common.h"
 #include "omap4-sar-layout.h"

 #if defined(CONFIG_SMP) && defined(CONFIG_PM)

 .macro	DO_SMC
 	dsb
 	smc	#0
 	dsb
 .endm

 ppa_zero_params:
 	.word		0x0

 ppa_por_params:
 	.word		1, 0

 /*
  * =============================
  * == CPU suspend finisher ==
  * =============================
  *
  * void omap4_finish_suspend(unsigned long cpu_state)
  *
  * This function code saves the CPU context and performs the CPU
  * power down sequence. Calling WFI effectively changes the CPU
  * power domains states to the desired target power state.
  *
  * @cpu_state : contains context save state (r0)
  *	0 - No context lost
  * 	1 - CPUx L1 and logic lost: MPUSS CSWR
  * 	2 - CPUx L1 and logic lost + GIC lost: MPUSS OSWR
  *	3 - CPUx L1 and logic lost + GIC + L2 lost: MPUSS OFF
  * @return: This function never returns for CPU OFF and DORMANT power states.
  * Post WFI, CPU transitions to DORMANT or OFF power state and on wake-up
  * from this follows a full CPU reset path via ROM code to CPU restore code.
  * The restore function pointer is stored at CPUx_WAKEUP_NS_PA_ADDR_OFFSET.
  * It returns to the caller for CPU INACTIVE and ON power states or in case
  * CPU failed to transition to targeted OFF/DORMANT state.
  */
 ENTRY(omap4_finish_suspend)
 	stmfd	sp!, {lr}
 	cmp	r0, #0x0
 	beq	do_WFI				@ No lowpower state, jump to WFI

 	/*
 	 * Flush all data from the L1 data cache before disabling
 	 * SCTLR.C bit.
 	 */
 	bl	omap4_get_sar_ram_base
 	ldr	r9, [r0, #OMAP_TYPE_OFFSET]
 	cmp	r9, #0x1			@ Check for HS device
 	bne	skip_secure_l1_clean
 	mov	r0, #SCU_PM_NORMAL
 	mov	r1, #0xFF			@ clean seucre L1
 	stmfd   r13!, {r4-r12, r14}
 	ldr	r12, =OMAP4_MON_SCU_PWR_INDEX
 	DO_SMC
 	ldmfd   r13!, {r4-r12, r14}
 skip_secure_l1_clean:
 	bl	v7_flush_dcache_all

 	/*
 	 * Clear the SCTLR.C bit to prevent further data cache
 	 * allocation. Clearing SCTLR.C would make all the data accesses
 	 * strongly ordered and would not hit the cache.
 	 */
 	mrc	p15, 0, r0, c1, c0, 0
 	bic	r0, r0, #(1 << 2)		@ Disable the C bit
 	mcr	p15, 0, r0, c1, c0, 0
 	isb

 	/*
 	 * Invalidate L1 data cache. Even though only invalidate is
 	 * necessary exported flush API is used here. Doing clean
 	 * on already clean cache would be almost NOP.
 	 */
 	bl	v7_flush_dcache_all

 	/*
 	 * Switch the CPU from Symmetric Multiprocessing (SMP) mode
 	 * to AsymmetricMultiprocessing (AMP) mode by programming
 	 * the SCU power status to DORMANT or OFF mode.
 	 * This enables the CPU to be taken out of coherency by
 	 * preventing the CPU from receiving cache, TLB, or BTB
 	 * maintenance operations broadcast by other CPUs in the cluster.
 	 */
 	bl	omap4_get_sar_ram_base
 	mov	r8, r0
 	ldr	r9, [r8, #OMAP_TYPE_OFFSET]
 	cmp	r9, #0x1			@ Check for HS device
 	bne	scu_gp_set
 	mrc	p15, 0, r0, c0, c0, 5		@ Read MPIDR
 	ands	r0, r0, #0x0f
 	ldreq	r0, [r8, #SCU_OFFSET0]
 	ldrne	r0, [r8, #SCU_OFFSET1]
 	mov	r1, #0x00
 	stmfd   r13!, {r4-r12, r14}
 	ldr	r12, =OMAP4_MON_SCU_PWR_INDEX
 	DO_SMC
 	ldmfd   r13!, {r4-r12, r14}
 	b	skip_scu_gp_set
 scu_gp_set:
 	mrc	p15, 0, r0, c0, c0, 5		@ Read MPIDR
 	ands	r0, r0, #0x0f
 	ldreq	r1, [r8, #SCU_OFFSET0]
 	ldrne	r1, [r8, #SCU_OFFSET1]
 	bl	omap4_get_scu_base
 	bl	scu_power_mode
 skip_scu_gp_set:
 	mrc	p15, 0, r0, c1, c1, 2		@ Read NSACR data
 	tst	r0, #(1 << 18)
 	mrcne	p15, 0, r0, c1, c0, 1
 	bicne	r0, r0, #(1 << 6)		@ Disable SMP bit
 	mcrne	p15, 0, r0, c1, c0, 1
 	isb
 	dsb
 #ifdef CONFIG_CACHE_L2X0
 	/*
 	 * Clean and invalidate the L2 cache.
 	 * Common cache-l2x0.c functions can't be used here since it
 	 * uses spinlocks. We are out of coherency here with data cache
 	 * disabled. The spinlock implementation uses exclusive load/store
 	 * instruction which can fail without data cache being enabled.
 	 * OMAP4 hardware doesn't support exclusive monitor which can
 	 * overcome exclusive access issue. Because of this, CPU can
 	 * lead to deadlock.
 	 */
 	bl	omap4_get_sar_ram_base
 	mov	r8, r0
 	mrc	p15, 0, r5, c0, c0, 5		@ Read MPIDR
 	ands	r5, r5, #0x0f
 	ldreq	r0, [r8, #L2X0_SAVE_OFFSET0]	@ Retrieve L2 state from SAR
 	ldrne	r0, [r8, #L2X0_SAVE_OFFSET1]	@ memory.
 	cmp	r0, #3
 	bne	do_WFI
 #ifdef CONFIG_PL310_ERRATA_727915
 	mov	r0, #0x03
 	mov	r12, #OMAP4_MON_L2X0_DBG_CTRL_INDEX
 	DO_SMC
 #endif
 	bl	omap4_get_l2cache_base
 	mov	r2, r0
 	ldr	r0, =0xffff
 	str	r0, [r2, #L2X0_CLEAN_INV_WAY]
 wait:
 	ldr	r0, [r2, #L2X0_CLEAN_INV_WAY]
 	ldr	r1, =0xffff
 	ands	r0, r0, r1
 	bne	wait
 #ifdef CONFIG_PL310_ERRATA_727915
 	mov	r0, #0x00
 	mov	r12, #OMAP4_MON_L2X0_DBG_CTRL_INDEX
 	DO_SMC
 #endif
 l2x_sync:
 	bl	omap4_get_l2cache_base
 	mov	r2, r0
 	mov	r0, #0x0
 	str	r0, [r2, #L2X0_CACHE_SYNC]
 sync:
 	ldr	r0, [r2, #L2X0_CACHE_SYNC]
 	ands	r0, r0, #0x1
 	bne	sync
 #endif

 do_WFI:
 	bl	omap_do_wfi

 	/*
 	 * CPU is here when it failed to enter OFF/DORMANT or
 	 * no low power state was attempted.
 	 */
 	mrc	p15, 0, r0, c1, c0, 0
 	tst	r0, #(1 << 2)			@ Check C bit enabled?
 	orreq	r0, r0, #(1 << 2)		@ Enable the C bit
 	mcreq	p15, 0, r0, c1, c0, 0
 	isb

 	/*
 	 * Ensure the CPU power state is set to NORMAL in
 	 * SCU power state so that CPU is back in coherency.
 	 * In non-coherent mode CPU can lock-up and lead to
 	 * system deadlock.
 	 */
 	mrc	p15, 0, r0, c1, c0, 1
 	tst	r0, #(1 << 6)			@ Check SMP bit enabled?
 	orreq	r0, r0, #(1 << 6)
 	mcreq	p15, 0, r0, c1, c0, 1
 	isb
 	bl	omap4_get_sar_ram_base
 	mov	r8, r0
 	ldr	r9, [r8, #OMAP_TYPE_OFFSET]
 	cmp	r9, #0x1			@ Check for HS device
 	bne	scu_gp_clear
 	mov	r0, #SCU_PM_NORMAL
 	mov	r1, #0x00
 	stmfd   r13!, {r4-r12, r14}
 	ldr	r12, =OMAP4_MON_SCU_PWR_INDEX
 	DO_SMC
 	ldmfd   r13!, {r4-r12, r14}
 	b	skip_scu_gp_clear
 scu_gp_clear:
 	bl	omap4_get_scu_base
 	mov	r1, #SCU_PM_NORMAL
 	bl	scu_power_mode
 skip_scu_gp_clear:
 	isb
 	dsb
 	ldmfd	sp!, {pc}
 ENDPROC(omap4_finish_suspend)

 /*
  * ============================
  * == CPU resume entry point ==
  * ============================
  *
  * void omap4_cpu_resume(void)
  *
  * ROM code jumps to this function while waking up from CPU
  * OFF or DORMANT state. Physical address of the function is
  * stored in the SAR RAM while entering to OFF or DORMANT mode.
  * The restore function pointer is stored at CPUx_WAKEUP_NS_PA_ADDR_OFFSET.
  */
 ENTRY(omap4_cpu_resume)
 	/*
 	 * Configure ACTRL and enable NS SMP bit access on CPU1 on HS device.
 	 * OMAP44XX EMU/HS devices - CPU0 SMP bit access is enabled in PPA
 	 * init and for CPU1, a secure PPA API provided. CPU0 must be ON
 	 * while executing NS_SMP API on CPU1 and PPA version must be 1.4.0+.
 	 * OMAP443X GP devices- SMP bit isn't accessible.
 	 * OMAP446X GP devices - SMP bit access is enabled on both CPUs.
 	 */
 	ldr	r8, =OMAP44XX_SAR_RAM_BASE
 	ldr	r9, [r8, #OMAP_TYPE_OFFSET]
 	cmp	r9, #0x1			@ Skip if GP device
 	bne	skip_ns_smp_enable
 	mrc     p15, 0, r0, c0, c0, 5
 	ands    r0, r0, #0x0f
 	beq	skip_ns_smp_enable
 ppa_actrl_retry:
 	mov     r0, #OMAP4_PPA_CPU_ACTRL_SMP_INDEX
 	adr	r3, ppa_zero_params		@ Pointer to parameters
 	mov	r1, #0x0			@ Process ID
 	mov	r2, #0x4			@ Flag
 	mov	r6, #0xff
 	mov	r12, #0x00			@ Secure Service ID
 	DO_SMC
 	cmp	r0, #0x0			@ API returns 0 on success.
 	beq	enable_smp_bit
 	b	ppa_actrl_retry
 enable_smp_bit:
 	mrc	p15, 0, r0, c1, c0, 1
 	tst	r0, #(1 << 6)			@ Check SMP bit enabled?
 	orreq	r0, r0, #(1 << 6)
 	mcreq	p15, 0, r0, c1, c0, 1
 	isb
 skip_ns_smp_enable:
 #ifdef CONFIG_CACHE_L2X0
 	/*
 	 * Restore the L2 AUXCTRL and enable the L2 cache.
 	 * OMAP4_MON_L2X0_AUXCTRL_INDEX =  Program the L2X0 AUXCTRL
 	 * OMAP4_MON_L2X0_CTRL_INDEX =  Enable the L2 using L2X0 CTRL
 	 * register r0 contains value to be programmed.
 	 * L2 cache is already invalidate by ROM code as part
 	 * of MPUSS OFF wakeup path.
 	 */
 	ldr	r2, =OMAP44XX_L2CACHE_BASE
 	ldr	r0, [r2, #L2X0_CTRL]
 	and	r0, #0x0f
 	cmp	r0, #1
 	beq	skip_l2en			@ Skip if already enabled
 	ldr	r3, =OMAP44XX_SAR_RAM_BASE
 	ldr	r1, [r3, #OMAP_TYPE_OFFSET]
 	cmp	r1, #0x1			@ Check for HS device
 	bne     set_gp_por
 	ldr     r0, =OMAP4_PPA_L2_POR_INDEX
 	ldr     r1, =OMAP44XX_SAR_RAM_BASE
 	ldr     r4, [r1, #L2X0_PREFETCH_CTRL_OFFSET]
 	adr     r3, ppa_por_params
 	str     r4, [r3, #0x04]
 	mov	r1, #0x0			@ Process ID
 	mov	r2, #0x4			@ Flag
 	mov	r6, #0xff
 	mov	r12, #0x00			@ Secure Service ID
 	DO_SMC
 	b	set_aux_ctrl
 set_gp_por:
 	ldr     r1, =OMAP44XX_SAR_RAM_BASE
 	ldr     r0, [r1, #L2X0_PREFETCH_CTRL_OFFSET]
 	ldr	r12, =OMAP4_MON_L2X0_PREFETCH_INDEX	@ Setup L2 PREFETCH
 	DO_SMC
 set_aux_ctrl:
 	ldr     r1, =OMAP44XX_SAR_RAM_BASE
 	ldr	r0, [r1, #L2X0_AUXCTRL_OFFSET]
 	ldr	r12, =OMAP4_MON_L2X0_AUXCTRL_INDEX	@ Setup L2 AUXCTRL
 	DO_SMC
 	mov	r0, #0x1
 	ldr	r12, =OMAP4_MON_L2X0_CTRL_INDEX		@ Enable L2 cache
 	DO_SMC
 skip_l2en:
 #endif

 	b	cpu_resume			@ Jump to generic resume
 ENDPROC(omap4_cpu_resume)
 #endif

 #ifndef CONFIG_OMAP4_ERRATA_I688
 ENTRY(omap_bus_sync)
 	mov	pc, lr
 ENDPROC(omap_bus_sync)
 #endif

 ENTRY(omap_do_wfi)
 	stmfd	sp!, {lr}
 	/* Drain interconnect write buffers. */
 	bl omap_bus_sync

 	/*
 	 * Execute an ISB instruction to ensure that all of the
 	 * CP15 register changes have been committed.
 	 */
 	isb

 	/*
 	 * Execute a barrier instruction to ensure that all cache,
 	 * TLB and branch predictor maintenance operations issued
 	 * by any CPU in the cluster have completed.
 	 */
 	dsb
 	dmb

 	/*
 	 * Execute a WFI instruction and wait until the
 	 * STANDBYWFI output is asserted to indicate that the
 	 * CPU is in idle and low power state. CPU can specualatively
 	 * prefetch the instructions so add NOPs after WFI. Sixteen
 	 * NOPs as per Cortex-A9 pipeline.
 	 */
 	wfi					@ Wait For Interrupt
 	nop
 	nop
 	nop
 	nop
 	nop
 	nop
 	nop
 	nop
 	nop
 	nop
 	nop
 	nop
 	nop
 	nop
 	nop
 	nop

 	ldmfd	sp!, {pc}
 ENDPROC(omap_do_wfi)
	/*
	* OMAP44xx sleep code.
	*
	* Copyright (C) 2011 Texas Instruments, Inc.
	* Santosh Shilimkar <santosh.shilimkar@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.
	*/

	#include <linux/linkage.h>
	#include <asm/system.h>
	#include <asm/smp_scu.h>
	#include <asm/memory.h>
	#include <asm/hardware/cache-l2x0.h>

	#include <plat/omap44xx.h>
	#include <mach/omap-secure.h>

	#include "common.h"
	#include "omap4-sar-layout.h"

	#if defined(CONFIG_SMP) && defined(CONFIG_PM)

	.macro DO_SMC
	dsb
	smc #0
	dsb
	.endm

	ppa_zero_params:
	.word 0x0

	ppa_por_params:
	.word 1, 0

	/*
	* =============================
	* == CPU suspend finisher ==
	* =============================
	*
	* void omap4_finish_suspend(unsigned long cpu_state)
	*
	* This function code saves the CPU context and performs the CPU
	* power down sequence. Calling WFI effectively changes the CPU
	* power domains states to the desired target power state.
	*
	* @cpu_state : contains context save state (r0)
	* 0 - No context lost
	* 1 - CPUx L1 and logic lost: MPUSS CSWR
	* 2 - CPUx L1 and logic lost + GIC lost: MPUSS OSWR
	* 3 - CPUx L1 and logic lost + GIC + L2 lost: MPUSS OFF
	* @return: This function never returns for CPU OFF and DORMANT power states.
	* Post WFI, CPU transitions to DORMANT or OFF power state and on wake-up
	* from this follows a full CPU reset path via ROM code to CPU restore code.
	* The restore function pointer is stored at CPUx_WAKEUP_NS_PA_ADDR_OFFSET.
	* It returns to the caller for CPU INACTIVE and ON power states or in case
	* CPU failed to transition to targeted OFF/DORMANT state.
	*/
	ENTRY(omap4_finish_suspend)
	stmfd sp!, {lr}
	cmp r0, #0x0
	beq do_WFI @ No lowpower state, jump to WFI

	/*
	* Flush all data from the L1 data cache before disabling
	* SCTLR.C bit.
	*/
	bl omap4_get_sar_ram_base
	ldr r9, [r0, #OMAP_TYPE_OFFSET]
	cmp r9, #0x1 @ Check for HS device
	bne skip_secure_l1_clean
	mov r0, #SCU_PM_NORMAL
	mov r1, #0xFF @ clean seucre L1
	stmfd r13!, {r4-r12, r14}
	ldr r12, =OMAP4_MON_SCU_PWR_INDEX
	DO_SMC
	ldmfd r13!, {r4-r12, r14}
	skip_secure_l1_clean:
	bl v7_flush_dcache_all

	/*
	* Clear the SCTLR.C bit to prevent further data cache
	* allocation. Clearing SCTLR.C would make all the data accesses
	* strongly ordered and would not hit the cache.
	*/
	mrc p15, 0, r0, c1, c0, 0
	bic r0, r0, #(1 << 2) @ Disable the C bit
	mcr p15, 0, r0, c1, c0, 0
	isb

	/*
	* Invalidate L1 data cache. Even though only invalidate is
	* necessary exported flush API is used here. Doing clean
	* on already clean cache would be almost NOP.
	*/
	bl v7_flush_dcache_all

	/*
	* Switch the CPU from Symmetric Multiprocessing (SMP) mode
	* to AsymmetricMultiprocessing (AMP) mode by programming
	* the SCU power status to DORMANT or OFF mode.
	* This enables the CPU to be taken out of coherency by
	* preventing the CPU from receiving cache, TLB, or BTB
	* maintenance operations broadcast by other CPUs in the cluster.
	*/
	bl omap4_get_sar_ram_base
	mov r8, r0
	ldr r9, [r8, #OMAP_TYPE_OFFSET]
	cmp r9, #0x1 @ Check for HS device
	bne scu_gp_set
	mrc p15, 0, r0, c0, c0, 5 @ Read MPIDR
	ands r0, r0, #0x0f
	ldreq r0, [r8, #SCU_OFFSET0]
	ldrne r0, [r8, #SCU_OFFSET1]
	mov r1, #0x00
	stmfd r13!, {r4-r12, r14}
	ldr r12, =OMAP4_MON_SCU_PWR_INDEX
	DO_SMC
	ldmfd r13!, {r4-r12, r14}
	b skip_scu_gp_set
	scu_gp_set:
	mrc p15, 0, r0, c0, c0, 5 @ Read MPIDR
	ands r0, r0, #0x0f
	ldreq r1, [r8, #SCU_OFFSET0]
	ldrne r1, [r8, #SCU_OFFSET1]
	bl omap4_get_scu_base
	bl scu_power_mode
	skip_scu_gp_set:
	mrc p15, 0, r0, c1, c1, 2 @ Read NSACR data
	tst r0, #(1 << 18)
	mrcne p15, 0, r0, c1, c0, 1
	bicne r0, r0, #(1 << 6) @ Disable SMP bit
	mcrne p15, 0, r0, c1, c0, 1
	isb
	dsb
	#ifdef CONFIG_CACHE_L2X0
	/*
	* Clean and invalidate the L2 cache.
	* Common cache-l2x0.c functions can't be used here since it
	* uses spinlocks. We are out of coherency here with data cache
	* disabled. The spinlock implementation uses exclusive load/store
	* instruction which can fail without data cache being enabled.
	* OMAP4 hardware doesn't support exclusive monitor which can
	* overcome exclusive access issue. Because of this, CPU can
	* lead to deadlock.
	*/
	bl omap4_get_sar_ram_base
	mov r8, r0
	mrc p15, 0, r5, c0, c0, 5 @ Read MPIDR
	ands r5, r5, #0x0f
	ldreq r0, [r8, #L2X0_SAVE_OFFSET0] @ Retrieve L2 state from SAR
	ldrne r0, [r8, #L2X0_SAVE_OFFSET1] @ memory.
	cmp r0, #3
	bne do_WFI
	#ifdef CONFIG_PL310_ERRATA_727915
	mov r0, #0x03
	mov r12, #OMAP4_MON_L2X0_DBG_CTRL_INDEX
	DO_SMC
	#endif
	bl omap4_get_l2cache_base
	mov r2, r0
	ldr r0, =0xffff
	str r0, [r2, #L2X0_CLEAN_INV_WAY]
	wait:
	ldr r0, [r2, #L2X0_CLEAN_INV_WAY]
	ldr r1, =0xffff
	ands r0, r0, r1
	bne wait
	#ifdef CONFIG_PL310_ERRATA_727915
	mov r0, #0x00
	mov r12, #OMAP4_MON_L2X0_DBG_CTRL_INDEX
	DO_SMC
	#endif
	l2x_sync:
	bl omap4_get_l2cache_base
	mov r2, r0
	mov r0, #0x0
	str r0, [r2, #L2X0_CACHE_SYNC]
	sync:
	ldr r0, [r2, #L2X0_CACHE_SYNC]
	ands r0, r0, #0x1
	bne sync
	#endif

	do_WFI:
	bl omap_do_wfi

	/*
	* CPU is here when it failed to enter OFF/DORMANT or
	* no low power state was attempted.
	*/
	mrc p15, 0, r0, c1, c0, 0
	tst r0, #(1 << 2) @ Check C bit enabled?
	orreq r0, r0, #(1 << 2) @ Enable the C bit
	mcreq p15, 0, r0, c1, c0, 0
	isb

	/*
	* Ensure the CPU power state is set to NORMAL in
	* SCU power state so that CPU is back in coherency.
	* In non-coherent mode CPU can lock-up and lead to
	* system deadlock.
	*/
	mrc p15, 0, r0, c1, c0, 1
	tst r0, #(1 << 6) @ Check SMP bit enabled?
	orreq r0, r0, #(1 << 6)
	mcreq p15, 0, r0, c1, c0, 1
	isb
	bl omap4_get_sar_ram_base
	mov r8, r0
	ldr r9, [r8, #OMAP_TYPE_OFFSET]
	cmp r9, #0x1 @ Check for HS device
	bne scu_gp_clear
	mov r0, #SCU_PM_NORMAL
	mov r1, #0x00
	stmfd r13!, {r4-r12, r14}
	ldr r12, =OMAP4_MON_SCU_PWR_INDEX
	DO_SMC
	ldmfd r13!, {r4-r12, r14}
	b skip_scu_gp_clear
	scu_gp_clear:
	bl omap4_get_scu_base
	mov r1, #SCU_PM_NORMAL
	bl scu_power_mode
	skip_scu_gp_clear:
	isb
	dsb
	ldmfd sp!, {pc}
	ENDPROC(omap4_finish_suspend)

	/*
	* ============================
	* == CPU resume entry point ==
	* ============================
	*
	* void omap4_cpu_resume(void)
	*
	* ROM code jumps to this function while waking up from CPU
	* OFF or DORMANT state. Physical address of the function is
	* stored in the SAR RAM while entering to OFF or DORMANT mode.
	* The restore function pointer is stored at CPUx_WAKEUP_NS_PA_ADDR_OFFSET.
	*/
	ENTRY(omap4_cpu_resume)
	/*
	* Configure ACTRL and enable NS SMP bit access on CPU1 on HS device.
	* OMAP44XX EMU/HS devices - CPU0 SMP bit access is enabled in PPA
	* init and for CPU1, a secure PPA API provided. CPU0 must be ON
	* while executing NS_SMP API on CPU1 and PPA version must be 1.4.0+.
	* OMAP443X GP devices- SMP bit isn't accessible.
	* OMAP446X GP devices - SMP bit access is enabled on both CPUs.
	*/
	ldr r8, =OMAP44XX_SAR_RAM_BASE
	ldr r9, [r8, #OMAP_TYPE_OFFSET]
	cmp r9, #0x1 @ Skip if GP device
	bne skip_ns_smp_enable
	mrc p15, 0, r0, c0, c0, 5
	ands r0, r0, #0x0f
	beq skip_ns_smp_enable
	ppa_actrl_retry:
	mov r0, #OMAP4_PPA_CPU_ACTRL_SMP_INDEX
	adr r3, ppa_zero_params @ Pointer to parameters
	mov r1, #0x0 @ Process ID
	mov r2, #0x4 @ Flag
	mov r6, #0xff
	mov r12, #0x00 @ Secure Service ID
	DO_SMC
	cmp r0, #0x0 @ API returns 0 on success.
	beq enable_smp_bit
	b ppa_actrl_retry
	enable_smp_bit:
	mrc p15, 0, r0, c1, c0, 1
	tst r0, #(1 << 6) @ Check SMP bit enabled?
	orreq r0, r0, #(1 << 6)
	mcreq p15, 0, r0, c1, c0, 1
	isb
	skip_ns_smp_enable:
	#ifdef CONFIG_CACHE_L2X0
	/*
	* Restore the L2 AUXCTRL and enable the L2 cache.
	* OMAP4_MON_L2X0_AUXCTRL_INDEX = Program the L2X0 AUXCTRL
	* OMAP4_MON_L2X0_CTRL_INDEX = Enable the L2 using L2X0 CTRL
	* register r0 contains value to be programmed.
	* L2 cache is already invalidate by ROM code as part
	* of MPUSS OFF wakeup path.
	*/
	ldr r2, =OMAP44XX_L2CACHE_BASE
	ldr r0, [r2, #L2X0_CTRL]
	and r0, #0x0f
	cmp r0, #1
	beq skip_l2en @ Skip if already enabled
	ldr r3, =OMAP44XX_SAR_RAM_BASE
	ldr r1, [r3, #OMAP_TYPE_OFFSET]
	cmp r1, #0x1 @ Check for HS device
	bne set_gp_por
	ldr r0, =OMAP4_PPA_L2_POR_INDEX
	ldr r1, =OMAP44XX_SAR_RAM_BASE
	ldr r4, [r1, #L2X0_PREFETCH_CTRL_OFFSET]
	adr r3, ppa_por_params
	str r4, [r3, #0x04]
	mov r1, #0x0 @ Process ID
	mov r2, #0x4 @ Flag
	mov r6, #0xff
	mov r12, #0x00 @ Secure Service ID
	DO_SMC
	b set_aux_ctrl
	set_gp_por:
	ldr r1, =OMAP44XX_SAR_RAM_BASE
	ldr r0, [r1, #L2X0_PREFETCH_CTRL_OFFSET]
	ldr r12, =OMAP4_MON_L2X0_PREFETCH_INDEX @ Setup L2 PREFETCH
	DO_SMC
	set_aux_ctrl:
	ldr r1, =OMAP44XX_SAR_RAM_BASE
	ldr r0, [r1, #L2X0_AUXCTRL_OFFSET]
	ldr r12, =OMAP4_MON_L2X0_AUXCTRL_INDEX @ Setup L2 AUXCTRL
	DO_SMC
	mov r0, #0x1
	ldr r12, =OMAP4_MON_L2X0_CTRL_INDEX @ Enable L2 cache
	DO_SMC
	skip_l2en:
	#endif

	b cpu_resume @ Jump to generic resume
	ENDPROC(omap4_cpu_resume)
	#endif

	#ifndef CONFIG_OMAP4_ERRATA_I688
	ENTRY(omap_bus_sync)
	mov pc, lr
	ENDPROC(omap_bus_sync)
	#endif

	ENTRY(omap_do_wfi)
	stmfd sp!, {lr}
	/* Drain interconnect write buffers. */
	bl omap_bus_sync

	/*
	* Execute an ISB instruction to ensure that all of the
	* CP15 register changes have been committed.
	*/
	isb

	/*
	* Execute a barrier instruction to ensure that all cache,
	* TLB and branch predictor maintenance operations issued
	* by any CPU in the cluster have completed.
	*/
	dsb
	dmb

	/*
	* Execute a WFI instruction and wait until the
	* STANDBYWFI output is asserted to indicate that the
	* CPU is in idle and low power state. CPU can specualatively
	* prefetch the instructions so add NOPs after WFI. Sixteen
	* NOPs as per Cortex-A9 pipeline.
	*/
	wfi @ Wait For Interrupt
	nop
	nop
	nop
	nop
	nop
	nop
	nop
	nop
	nop
	nop
	nop
	nop
	nop
	nop
	nop
	nop

	ldmfd sp!, {pc}
	ENDPROC(omap_do_wfi)