linux/arch/arm/mach-tegra/sleep.S
Peter De Schrijver c76fcc8af1 ARM: tegra: assembler code for LP3
Configure the flow controller for clockgating and enter WFI

Based on work by:

Colin Cross <ccross@android.com>
Gary King <gking@nvidia.com>

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Colin Cross <ccross@android.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
2012-02-06 09:16:16 -08:00

92 lines
2.5 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 <mach/io.h>
#include <mach/iomap.h>
#include "flowctrl.h"
#define TEGRA_FLOW_CTRL_VIRT (TEGRA_FLOW_CTRL_BASE - IO_PPSB_PHYS \
+ IO_PPSB_VIRT)
/* returns the offset of the flow controller halt register for a cpu */
.macro cpu_to_halt_reg rd, rcpu
cmp \rcpu, #0
subne \rd, \rcpu, #1
movne \rd, \rd, lsl #3
addne \rd, \rd, #0x14
moveq \rd, #0
.endm
/* returns the offset of the flow controller csr register for a cpu */
.macro cpu_to_csr_reg rd, rcpu
cmp \rcpu, #0
subne \rd, \rcpu, #1
movne \rd, \rd, lsl #3
addne \rd, \rd, #0x18
moveq \rd, #8
.endm
/* returns the ID of the current processor */
.macro cpu_id, rd
mrc p15, 0, \rd, c0, c0, 5
and \rd, \rd, #0xF
.endm
/* loads a 32-bit value into a register without a data access */
.macro mov32, reg, val
movw \reg, #:lower16:\val
movt \reg, #:upper16:\val
.endm
/*
* tegra_cpu_wfi
*
* puts current CPU in clock-gated wfi using the flow controller
*
* corrupts r0-r3
* must be called with MMU on
*/
ENTRY(tegra_cpu_wfi)
cpu_id r0
cpu_to_halt_reg r1, r0
cpu_to_csr_reg r2, r0
mov32 r0, TEGRA_FLOW_CTRL_VIRT
mov r3, #FLOW_CTRL_CSR_INTR_FLAG | FLOW_CTRL_CSR_EVENT_FLAG
str r3, [r0, r2] @ clear event & interrupt status
mov r3, #FLOW_CTRL_WAIT_FOR_INTERRUPT | FLOW_CTRL_JTAG_RESUME
str r3, [r0, r1] @ put flow controller in wait irq mode
dsb
wfi
mov r3, #0
str r3, [r0, r1] @ clear flow controller halt status
mov r3, #FLOW_CTRL_CSR_INTR_FLAG | FLOW_CTRL_CSR_EVENT_FLAG
str r3, [r0, r2] @ clear event & interrupt status
dsb
mov pc, lr
ENDPROC(tegra_cpu_wfi)