diff options
Diffstat (limited to 'arch/arm/mach-tegra/sleep-t30.S')
| -rw-r--r-- | arch/arm/mach-tegra/sleep-t30.S | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/arch/arm/mach-tegra/sleep-t30.S b/arch/arm/mach-tegra/sleep-t30.S new file mode 100644 index 00000000000..777d9cee8b9 --- /dev/null +++ b/arch/arm/mach-tegra/sleep-t30.S @@ -0,0 +1,107 @@ +/* + * 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 <mach/iomap.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 |