linux/arch/arm/mach-tegra/sleep.S
Joseph Lo 29a0e7beab ARM: tegra: retain L2 content over CPU suspend/resume
The L2 RAM is in different power domain from the CPU cluster. So the
L2 content can be retained over CPU suspend/resume. To do that, we
need to disable L2 after the MMU is disabled, and enable L2 before
the MMU is enabled. But the L2 controller is in the same power domain
with the CPU cluster. We need to restore it's settings and re-enable
it after the power be resumed.

Signed-off-by: Joseph Lo <josephl@nvidia.com>
Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
2012-11-15 15:09:22 -07:00

112 lines
2.6 KiB
ArmAsm

/*
* arch/arm/mach-tegra/sleep.S
*
* Copyright (c) 2010-2011, NVIDIA Corporation.
* Copyright (c) 2011, Google, Inc.
*
* Author: Colin Cross <ccross@android.com>
* Gary King <gking@nvidia.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/cache.h>
#include <asm/cp15.h>
#include <asm/hardware/cache-l2x0.h>
#include "iomap.h"
#include "flowctrl.h"
#include "sleep.h"
#ifdef CONFIG_PM_SLEEP
/*
* tegra_disable_clean_inv_dcache
*
* disable, clean & invalidate the D-cache
*
* Corrupted registers: r1-r3, r6, r8, r9-r11
*/
ENTRY(tegra_disable_clean_inv_dcache)
stmfd sp!, {r0, r4-r5, r7, r9-r11, lr}
dmb @ ensure ordering
/* Disable the D-cache */
mrc p15, 0, r2, c1, c0, 0
bic r2, r2, #CR_C
mcr p15, 0, r2, c1, c0, 0
isb
/* Flush the D-cache */
bl v7_flush_dcache_louis
/* Trun off coherency */
exit_smp r4, r5
ldmfd sp!, {r0, r4-r5, r7, r9-r11, pc}
ENDPROC(tegra_disable_clean_inv_dcache)
/*
* tegra_sleep_cpu_finish(unsigned long v2p)
*
* enters suspend in LP2 by turning off the mmu and jumping to
* tegra?_tear_down_cpu
*/
ENTRY(tegra_sleep_cpu_finish)
/* Flush and disable the L1 data cache */
bl tegra_disable_clean_inv_dcache
mov32 r6, tegra_tear_down_cpu
ldr r1, [r6]
add r1, r1, r0
mov32 r3, tegra_shut_off_mmu
add r3, r3, r0
mov r0, r1
mov pc, r3
ENDPROC(tegra_sleep_cpu_finish)
/*
* tegra_shut_off_mmu
*
* r0 = physical address to jump to with mmu off
*
* called with VA=PA mapping
* turns off MMU, icache, dcache and branch prediction
*/
.align L1_CACHE_SHIFT
.pushsection .idmap.text, "ax"
ENTRY(tegra_shut_off_mmu)
mrc p15, 0, r3, c1, c0, 0
movw r2, #CR_I | CR_Z | CR_C | CR_M
bic r3, r3, r2
dsb
mcr p15, 0, r3, c1, c0, 0
isb
#ifdef CONFIG_CACHE_L2X0
/* Disable L2 cache */
mov32 r4, TEGRA_ARM_PERIF_BASE + 0x3000
mov r5, #0
str r5, [r4, #L2X0_CTRL]
#endif
mov pc, r0
ENDPROC(tegra_shut_off_mmu)
.popsection
#endif