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/*
* Copyright (c) 2012, NVIDIA Corporation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include "sleep.h"
#include "flowctrl.h"
#define TEGRA30_POWER_HOTPLUG_SHUTDOWN (1 << 27) /* Hotplug shutdown */
#if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_PM_SLEEP)
/*
* tegra30_hotplug_shutdown(void)
*
* Powergates the current CPU.
* Should never return.
*/
ENTRY(tegra30_hotplug_shutdown)
/* Turn off SMP coherency */
exit_smp r4, r5
/* Powergate this CPU */
mov r0, #TEGRA30_POWER_HOTPLUG_SHUTDOWN
bl tegra30_cpu_shutdown
mov pc, lr @ should never get here
ENDPROC(tegra30_hotplug_shutdown)
/*
* tegra30_cpu_shutdown(unsigned long flags)
*
* Puts the current CPU in wait-for-event mode on the flow controller
* and powergates it -- flags (in R0) indicate the request type.
* Must never be called for CPU 0.
*
* corrupts r0-r4, r12
*/
ENTRY(tegra30_cpu_shutdown)
cpu_id r3
cmp r3, #0
moveq pc, lr @ Must never be called for CPU 0
ldr r12, =TEGRA_FLOW_CTRL_VIRT
cpu_to_csr_reg r1, r3
add r1, r1, r12 @ virtual CSR address for this CPU
cpu_to_halt_reg r2, r3
add r2, r2, r12 @ virtual HALT_EVENTS address for this CPU
/*
* Clear this CPU's "event" and "interrupt" flags and power gate
* it when halting but not before it is in the "WFE" state.
*/
movw r12, \
FLOW_CTRL_CSR_INTR_FLAG | FLOW_CTRL_CSR_EVENT_FLAG | \
FLOW_CTRL_CSR_ENABLE
mov r4, #(1 << 4)
orr r12, r12, r4, lsl r3
str r12, [r1]
/* Halt this CPU. */
mov r3, #0x400
delay_1:
subs r3, r3, #1 @ delay as a part of wfe war.
bge delay_1;
cpsid a @ disable imprecise aborts.
ldr r3, [r1] @ read CSR
str r3, [r1] @ clear CSR
tst r0, #TEGRA30_POWER_HOTPLUG_SHUTDOWN
movne r3, #FLOW_CTRL_WAITEVENT @ For hotplug
str r3, [r2]
ldr r0, [r2]
b wfe_war
__cpu_reset_again:
dsb
.align 5
wfe @ CPU should be power gated here
wfe_war:
b __cpu_reset_again
/*
* 38 nop's, which fills reset of wfe cache line and
* 4 more cachelines with nop
*/
.rept 38
nop
.endr
b . @ should never get here
ENDPROC(tegra30_cpu_shutdown)
#endif
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