[ARM] pxa: add preliminary suspend/resume code for pxa3xx
1. clear RDH bit after resuming back from D3, otherwise, the multi function
pins will retain the low power state
2. save/restore essential system registers
Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mach-pxa/sleep.S b/arch/arm/mach-pxa/sleep.S
index 14bb4a9..784716e 100644
--- a/arch/arm/mach-pxa/sleep.S
+++ b/arch/arm/mach-pxa/sleep.S
@@ -50,6 +50,108 @@
str r0, [r1]
ldr pc, [sp], #4
+#ifdef CONFIG_PXA3xx
+/*
+ * pxa3xx_cpu_suspend() - forces CPU into sleep state (S2D3C4)
+ *
+ * NOTE: unfortunately, pxa_cpu_save_cp can not be reused here since
+ * the auxiliary control register address is different between pxa3xx
+ * and pxa{25x,27x}
+ */
+
+ENTRY(pxa3xx_cpu_suspend)
+
+#ifndef CONFIG_IWMMXT
+ mra r2, r3, acc0
+#endif
+ stmfd sp!, {r2 - r12, lr} @ save registers on stack
+
+ mrc p14, 0, r3, c6, c0, 0 @ clock configuration, for turbo mode
+ mrc p15, 0, r4, c15, c1, 0 @ CP access reg
+ mrc p15, 0, r5, c13, c0, 0 @ PID
+ mrc p15, 0, r6, c3, c0, 0 @ domain ID
+ mrc p15, 0, r7, c2, c0, 0 @ translation table base addr
+ mrc p15, 0, r8, c1, c0, 1 @ auxiliary control reg
+ mrc p15, 0, r9, c1, c0, 0 @ control reg
+
+ bic r3, r3, #2 @ clear frequency change bit
+
+ @ store them plus current virtual stack ptr on stack
+ mov r10, sp
+ stmfd sp!, {r3 - r10}
+
+ @ store physical address of stack pointer
+ mov r0, sp
+ bl sleep_phys_sp
+ ldr r1, =sleep_save_sp
+ str r0, [r1]
+
+ @ clean data cache
+ bl xsc3_flush_kern_cache_all
+
+ mov r0, #0x06 @ S2D3C4 mode
+ mcr p14, 0, r0, c7, c0, 0 @ enter sleep
+
+20: b 20b @ waiting for sleep
+
+ .data
+ .align 5
+/*
+ * pxa3xx_cpu_resume
+ */
+
+ENTRY(pxa3xx_cpu_resume)
+
+ mov r0, #PSR_I_BIT | PSR_F_BIT | SVC_MODE @ set SVC, irqs off
+ msr cpsr_c, r0
+
+ ldr r0, sleep_save_sp @ stack phys addr
+ ldmfd r0, {r3 - r9, sp} @ CP regs + virt stack ptr
+
+ mov r1, #0
+ mcr p15, 0, r1, c7, c7, 0 @ invalidate I & D caches, BTB
+ mcr p15, 0, r1, c7, c10, 4 @ drain write (&fill) buffer
+ mcr p15, 0, r1, c7, c5, 4 @ flush prefetch buffer
+ mcr p15, 0, r1, c8, c7, 0 @ invalidate I & D TLBs
+
+ mcr p14, 0, r3, c6, c0, 0 @ clock configuration, turbo mode.
+ mcr p15, 0, r4, c15, c1, 0 @ CP access reg
+ mcr p15, 0, r5, c13, c0, 0 @ PID
+ mcr p15, 0, r6, c3, c0, 0 @ domain ID
+ mcr p15, 0, r7, c2, c0, 0 @ translation table base addr
+ mcr p15, 0, r8, c1, c0, 1 @ auxiliary control reg
+
+ @ temporarily map resume_turn_on_mmu into the page table,
+ @ otherwise prefetch abort occurs after MMU is turned on
+ mov r1, r7
+ bic r1, r1, #0x00ff
+ bic r1, r1, #0x3f00
+ ldr r2, =0x542e
+
+ adr r3, resume_turn_on_mmu
+ mov r3, r3, lsr #20
+ orr r4, r2, r3, lsl #20
+ ldr r5, [r1, r3, lsl #2]
+ str r4, [r1, r3, lsl #2]
+
+ @ Mapping page table address in the page table
+ mov r6, r1, lsr #20
+ orr r7, r2, r6, lsl #20
+ ldr r8, [r1, r6, lsl #2]
+ str r7, [r1, r6, lsl #2]
+
+ ldr r2, =pxa3xx_resume_after_mmu @ absolute virtual address
+ b resume_turn_on_mmu @ cache align execution
+
+ .text
+pxa3xx_resume_after_mmu:
+ /* restore the temporary mapping */
+ str r5, [r1, r3, lsl #2]
+ str r8, [r1, r6, lsl #2]
+ b resume_after_mmu
+
+#endif /* CONFIG_PXA3xx */
+
#ifdef CONFIG_PXA27x
/*
* pxa27x_cpu_suspend()