ARM: OMAP4: PM: Add CPUX OFF mode support

This patch adds the CPU0 and CPU1 off mode support. CPUX close switch
retention (CSWR) is not supported by hardware design.

The CPUx OFF mode isn't supported on OMAP4430 ES1.0

CPUx sleep code is common for hotplug, suspend and CPUilde.

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Vishwanath BS <vishwanath.bs@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>

1 files changed, 276 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/sleep44xx.S b/arch/arm/mach-omap2/sleep44xx.S
new file mode 100644
index 000000000000..e5521945ba8e
--- /dev/null
+++ b/arch/arm/mach-omap2/sleep44xx.S
@@ -0,0 +1,276 @@
+/*
+ * 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
+
+/*
+ * =============================
+ * == 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
+
+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:
+
+	b	cpu_resume			@ Jump to generic resume
+ENDPROC(omap4_cpu_resume)
+#endif
+
+ENTRY(omap_do_wfi)
+	stmfd	sp!, {lr}
+
+	/*
+	 * 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)