diff options
Diffstat (limited to 'arch/arm/mach-pxa/sleep.S')
| -rw-r--r-- | arch/arm/mach-pxa/sleep.S | 56 |
1 files changed, 50 insertions, 6 deletions
diff --git a/arch/arm/mach-pxa/sleep.S b/arch/arm/mach-pxa/sleep.S index 16cad2c2497..5786ccad938 100644 --- a/arch/arm/mach-pxa/sleep.S +++ b/arch/arm/mach-pxa/sleep.S @@ -18,6 +18,11 @@ #include <asm/arch/pxa-regs.h> +#ifdef CONFIG_PXA27x // workaround for Errata 50 +#define MDREFR_KDIV 0x200a4000 // all banks +#define CCCR_SLEEP 0x00000107 // L=7 2N=2 A=0 PPDIS=0 CPDIS=0 +#endif + .text /* @@ -28,7 +33,9 @@ ENTRY(pxa_cpu_suspend) +#ifndef CONFIG_IWMMXT mra r2, r3, acc0 +#endif stmfd sp!, {r2 - r12, lr} @ save registers on stack @ get coprocessor registers @@ -61,14 +68,23 @@ ENTRY(pxa_cpu_suspend) @ prepare value for sleep mode mov r1, #3 @ sleep mode - @ prepare to put SDRAM into self-refresh manually + @ prepare pointer to physical address 0 (virtual mapping in generic.c) + mov r2, #UNCACHED_PHYS_0 + + @ prepare SDRAM refresh settings ldr r4, =MDREFR ldr r5, [r4] + + @ enable SDRAM self-refresh mode orr r5, r5, #MDREFR_SLFRSH - @ prepare pointer to physical address 0 (virtual mapping in generic.c) - mov r2, #UNCACHED_PHYS_0 +#ifdef CONFIG_PXA27x + @ set SDCLKx divide-by-2 bits (this is part of a workaround for Errata 50) + ldr r6, =MDREFR_KDIV + orr r5, r5, r6 +#endif +#ifdef CONFIG_PXA25x @ Intel PXA255 Specification Update notes problems @ about suspending with PXBus operating above 133MHz @ (see Errata 31, GPIO output signals, ... unpredictable in sleep @@ -100,6 +116,18 @@ ENTRY(pxa_cpu_suspend) mov r0, #0 mcr p14, 0, r0, c6, c0, 0 orr r0, r0, #2 @ initiate change bit +#endif +#ifdef CONFIG_PXA27x + @ Intel PXA270 Specification Update notes problems sleeping + @ with core operating above 91 MHz + @ (see Errata 50, ...processor does not exit from sleep...) + + ldr r6, =CCCR + ldr r8, [r6] @ keep original value for resume + + ldr r7, =CCCR_SLEEP @ prepare CCCR sleep value + mov r0, #0x2 @ prepare value for CLKCFG +#endif @ align execution to a cache line b 1f @@ -111,6 +139,7 @@ ENTRY(pxa_cpu_suspend) @ All needed values are now in registers. @ These last instructions should be in cache +#if defined(CONFIG_PXA25x) || defined(CONFIG_PXA27x) @ initiate the frequency change... str r7, [r6] mcr p14, 0, r0, c6, c0, 0 @@ -118,14 +147,27 @@ ENTRY(pxa_cpu_suspend) @ restore the original cpu speed value for resume str r8, [r6] - @ put SDRAM into self-refresh - str r5, [r4] + @ need 6 13-MHz cycles before changing PWRMODE + @ just set frequency to 91-MHz... 6*91/13 = 42 + + mov r0, #42 +10: subs r0, r0, #1 + bne 10b +#endif + + @ Do not reorder... + @ Intel PXA270 Specification Update notes problems performing + @ external accesses after SDRAM is put in self-refresh mode + @ (see Errata 39 ...hangs when entering self-refresh mode) @ force address lines low by reading at physical address 0 ldr r3, [r2] + @ put SDRAM into self-refresh + str r5, [r4] + @ enter sleep mode - mcr p14, 0, r1, c7, c0, 0 + mcr p14, 0, r1, c7, c0, 0 @ PWRMODE 20: b 20b @ loop waiting for sleep @@ -188,7 +230,9 @@ resume_after_mmu: bl cpu_xscale_proc_init #endif ldmfd sp!, {r2, r3} +#ifndef CONFIG_IWMMXT mar acc0, r2, r3 +#endif ldmfd sp!, {r4 - r12, pc} @ return to caller |