2 * Copyright (c) 2012, NVIDIA Corporation. All rights reserved.
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * You should have received a copy of the GNU General Public License
14 * along with this program. If not, see <http://www.gnu.org/licenses/>.
17 #include <linux/linkage.h>
19 #include <asm/assembler.h>
20 #include <asm/asm-offsets.h>
26 #define TEGRA30_POWER_HOTPLUG_SHUTDOWN (1 << 27) /* Hotplug shutdown */
28 #if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_PM_SLEEP)
30 * tegra30_hotplug_shutdown(void)
32 * Powergates the current CPU.
33 * Should never return.
35 ENTRY(tegra30_hotplug_shutdown)
36 /* Powergate this CPU */
37 mov r0, #TEGRA30_POWER_HOTPLUG_SHUTDOWN
38 bl tegra30_cpu_shutdown
39 mov pc, lr @ should never get here
40 ENDPROC(tegra30_hotplug_shutdown)
43 * tegra30_cpu_shutdown(unsigned long flags)
45 * Puts the current CPU in wait-for-event mode on the flow controller
46 * and powergates it -- flags (in R0) indicate the request type.
49 * corrupts r0-r4, r10-r12
51 ENTRY(tegra30_cpu_shutdown)
53 tegra_get_soc_id TEGRA_APB_MISC_VIRT, r10
55 bne _no_cpu0_chk @ It's not Tegra30
58 moveq pc, lr @ Must never be called for CPU 0
61 ldr r12, =TEGRA_FLOW_CTRL_VIRT
63 add r1, r1, r12 @ virtual CSR address for this CPU
64 cpu_to_halt_reg r2, r3
65 add r2, r2, r12 @ virtual HALT_EVENTS address for this CPU
68 * Clear this CPU's "event" and "interrupt" flags and power gate
69 * it when halting but not before it is in the "WFE" state.
72 FLOW_CTRL_CSR_INTR_FLAG | FLOW_CTRL_CSR_EVENT_FLAG | \
75 moveq r4, #(1 << 4) @ wfe bitmap
76 movne r4, #(1 << 8) @ wfi bitmap
77 ARM( orr r12, r12, r4, lsl r3 )
78 THUMB( lsl r4, r4, r3 )
79 THUMB( orr r12, r12, r4 )
85 subs r3, r3, #1 @ delay as a part of wfe war.
87 cpsid a @ disable imprecise aborts.
88 ldr r3, [r1] @ read CSR
89 str r3, [r1] @ clear CSR
91 tst r0, #TEGRA30_POWER_HOTPLUG_SHUTDOWN
92 beq flow_ctrl_setting_for_lp2
94 /* flow controller set up for hotplug */
95 mov r3, #FLOW_CTRL_WAITEVENT @ For hotplug
97 flow_ctrl_setting_for_lp2:
98 /* flow controller set up for LP2 */
100 moveq r3, #FLOW_CTRL_WAIT_FOR_INTERRUPT @ For LP2
101 movne r3, #FLOW_CTRL_WAITEVENT
111 wfeeq @ CPU should be power gated here
117 * 38 nop's, which fills reset of wfe cache line and
118 * 4 more cachelines with nop
123 b . @ should never get here
125 ENDPROC(tegra30_cpu_shutdown)
128 #ifdef CONFIG_PM_SLEEP
130 * tegra30_sleep_cpu_secondary_finish(unsigned long v2p)
132 * Enters LP2 on secondary CPU by exiting coherency and powergating the CPU.
134 ENTRY(tegra30_sleep_cpu_secondary_finish)
137 /* Flush and disable the L1 data cache */
138 bl tegra_disable_clean_inv_dcache
140 /* Powergate this CPU. */
141 mov r0, #0 @ power mode flags (!hotplug)
142 bl tegra30_cpu_shutdown
143 mov r0, #1 @ never return here
145 ENDPROC(tegra30_sleep_cpu_secondary_finish)
148 * tegra30_tear_down_cpu
150 * Switches the CPU to enter sleep.
152 ENTRY(tegra30_tear_down_cpu)
153 mov32 r6, TEGRA_FLOW_CTRL_BASE
155 b tegra30_enter_sleep
156 ENDPROC(tegra30_tear_down_cpu)
159 * tegra30_enter_sleep
161 * uses flow controller to enter sleep state
162 * executes from IRAM with SDRAM in selfrefresh when target state is LP0 or LP1
163 * executes from SDRAM with target state is LP2
164 * r6 = TEGRA_FLOW_CTRL_BASE
169 cpu_to_csr_reg r2, r1
171 orr r0, r0, #FLOW_CTRL_CSR_INTR_FLAG | FLOW_CTRL_CSR_EVENT_FLAG
172 orr r0, r0, #FLOW_CTRL_CSR_ENABLE
175 mov r0, #FLOW_CTRL_WAIT_FOR_INTERRUPT
176 orr r0, r0, #FLOW_CTRL_HALT_CPU_IRQ | FLOW_CTRL_HALT_CPU_FIQ
177 cpu_to_halt_reg r2, r1
180 ldr r0, [r6, r2] /* memory barrier */
185 wfi /* CPU should be power gated here */
187 /* !!!FIXME!!! Implement halt failure handler */