diff options
Diffstat (limited to 'kernel/arch/arm/mach-pxa/sleep.S')
| -rw-r--r-- | kernel/arch/arm/mach-pxa/sleep.S | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/kernel/arch/arm/mach-pxa/sleep.S b/kernel/arch/arm/mach-pxa/sleep.S new file mode 100644 index 000000000..6c5b3ffd2 --- /dev/null +++ b/kernel/arch/arm/mach-pxa/sleep.S @@ -0,0 +1,171 @@ +/* + * Low-level PXA250/210 sleep/wakeUp support + * + * Initial SA1110 code: + * Copyright (c) 2001 Cliff Brake <cbrake@accelent.com> + * + * Adapted for PXA by Nicolas Pitre: + * Copyright (c) 2002 Monta Vista Software, Inc. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License. + */ + +#include <linux/linkage.h> +#include <asm/assembler.h> +#include <mach/hardware.h> +#include <mach/smemc.h> +#include <mach/pxa2xx-regs.h> + +#define MDREFR_KDIV 0x200a4000 // all banks +#define CCCR_SLEEP 0x00000107 // L=7 2N=2 A=0 PPDIS=0 CPDIS=0 + + .text + +#ifdef CONFIG_PXA3xx +/* + * pxa3xx_finish_suspend() - forces CPU into sleep state (S2D3C4) + */ +ENTRY(pxa3xx_finish_suspend) + mov r0, #0x06 @ S2D3C4 mode + mcr p14, 0, r0, c7, c0, 0 @ enter sleep + +20: b 20b @ waiting for sleep +#endif /* CONFIG_PXA3xx */ + +#ifdef CONFIG_PXA27x +/* + * pxa27x_finish_suspend() + * + * Forces CPU into sleep state. + * + * r0 = value for PWRMODE M field for desired sleep state + */ +ENTRY(pxa27x_finish_suspend) + @ Put the processor to sleep + @ (also workaround for sighting 28071) + + @ prepare value for sleep mode + mov r1, r0 @ sleep mode + + @ 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 + + @ set SDCLKx divide-by-2 bits (this is part of a workaround for Errata 50) + ldr r6, =MDREFR_KDIV + orr r5, r5, r6 + + @ 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 + + @ align execution to a cache line + b pxa_cpu_do_suspend +#endif + +#ifdef CONFIG_PXA25x +/* + * pxa25x_finish_suspend() + * + * Forces CPU into sleep state. + * + * r0 = value for PWRMODE M field for desired sleep state + */ + +ENTRY(pxa25x_finish_suspend) + @ prepare value for sleep mode + mov r1, r0 @ sleep mode + + @ 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 + + @ Intel PXA255 Specification Update notes problems + @ about suspending with PXBus operating above 133MHz + @ (see Errata 31, GPIO output signals, ... unpredictable in sleep + @ + @ We keep the change-down close to the actual suspend on SDRAM + @ as possible to eliminate messing about with the refresh clock + @ as the system will restore with the original speed settings + @ + @ Ben Dooks, 13-Sep-2004 + + ldr r6, =CCCR + ldr r8, [r6] @ keep original value for resume + + @ ensure x1 for run and turbo mode with memory clock + bic r7, r8, #CCCR_M_MASK | CCCR_N_MASK + orr r7, r7, #(1<<5) | (2<<7) + + @ check that the memory frequency is within limits + and r14, r7, #CCCR_L_MASK + teq r14, #1 + bicne r7, r7, #CCCR_L_MASK + orrne r7, r7, #1 @@ 99.53MHz + + @ get ready for the change + + @ note, turbo is not preserved over sleep so there is no + @ point in preserving it here. we save it on the stack with the + @ other CP registers instead. + mov r0, #0 + mcr p14, 0, r0, c6, c0, 0 + orr r0, r0, #2 @ initiate change bit + b pxa_cpu_do_suspend +#endif + + .ltorg + .align 5 +pxa_cpu_do_suspend: + + @ All needed values are now in registers. + @ These last instructions should be in cache + + @ initiate the frequency change... + str r7, [r6] + mcr p14, 0, r0, c6, c0, 0 + + @ restore the original cpu speed value for resume + str r8, [r6] + + @ 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 + + @ Do not reorder... + @ Intel PXA270 Specification Update notes problems performing + @ external accesses after SDRAM is put in self-refresh mode + @ (see Errata 38 ...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 @ PWRMODE + +20: b 20b @ loop waiting for sleep |