xref: /openbmc/u-boot/arch/arm/mach-tegra/psci.S (revision ad3098f7)
1/*
2 * Copyright (C) 2014, NVIDIA
3 * Copyright (C) 2015, Siemens AG
4 *
5 * Authors:
6 *  Thierry Reding <treding@nvidia.com>
7 *  Jan Kiszka <jan.kiszka@siemens.com>
8 *
9 * SPDX-License-Identifier:	GPL-2.0+
10 */
11
12#include <linux/linkage.h>
13#include <asm/macro.h>
14#include <asm/psci.h>
15
16	.pushsection ._secure.text, "ax"
17	.arch_extension sec
18
19#define TEGRA_SB_CSR_0			0x6000c200
20#define NS_RST_VEC_WR_DIS		(1 << 1)
21
22#define TEGRA_RESET_EXCEPTION_VECTOR	0x6000f100
23
24#define TEGRA_FLOW_CTRL_BASE		0x60007000
25#define FLOW_CTRL_CPU_CSR		0x08
26#define CSR_ENABLE			(1 << 0)
27#define CSR_IMMEDIATE_WAKE		(1 << 3)
28#define CSR_WAIT_WFI_SHIFT		8
29#define FLOW_CTRL_CPU1_CSR		0x18
30
31@ converts CPU ID into FLOW_CTRL_CPUn_CSR offset
32.macro get_csr_reg cpu, ofs, tmp
33	cmp	\cpu, #0		@ CPU0?
34	lsl	\tmp, \cpu, #3	@ multiple by 8 (register offset CPU1-3)
35	moveq	\ofs, #FLOW_CTRL_CPU_CSR
36	addne	\ofs, \tmp, #FLOW_CTRL_CPU1_CSR - 8
37.endm
38
39ENTRY(psci_arch_init)
40	mov	r6, lr
41
42	mrc	p15, 0, r5, c1, c1, 0	@ Read SCR
43	bic	r5, r5, #1		@ Secure mode
44	mcr	p15, 0, r5, c1, c1, 0	@ Write SCR
45	isb
46
47	@ lock reset vector for non-secure
48	ldr	r4, =TEGRA_SB_CSR_0
49	ldr	r5, [r4]
50	orr	r5, r5, #NS_RST_VEC_WR_DIS
51	str	r5, [r4]
52
53	bl	psci_get_cpu_id		@ CPU ID => r0
54
55	adr	r5, _sys_clock_freq
56	cmp	r0, #0
57
58	mrceq	p15, 0, r7, c14, c0, 0	@ read CNTFRQ from CPU0
59	streq	r7, [r5]
60
61	ldrne	r7, [r5]
62	mcrne	p15, 0, r7, c14, c0, 0	@ write CNTFRQ to CPU1..3
63
64	bl	psci_get_cpu_stack_top	@ stack top => r0
65	mov	sp, r0
66
67	bx	r6
68ENDPROC(psci_arch_init)
69
70_sys_clock_freq:
71	.word	0
72
73ENTRY(psci_cpu_off)
74	bl	psci_cpu_off_common
75
76	bl	psci_get_cpu_id		@ CPU ID => r0
77
78	get_csr_reg r0, r2, r3
79
80	ldr	r6, =TEGRA_FLOW_CTRL_BASE
81	mov	r5, #(CSR_ENABLE)
82	mov	r4, #(1 << CSR_WAIT_WFI_SHIFT)
83	add	r5, r4, lsl r0
84	str	r5, [r6, r2]
85
86_loop:	wfi
87	b	_loop
88ENDPROC(psci_cpu_off)
89
90ENTRY(psci_cpu_on)
91	push	{lr}
92
93	mov	r0, r1
94	bl	psci_get_cpu_stack_top	@ get stack top of target CPU
95	str	r2, [r0]		@ store target PC at stack top
96	dsb
97
98	ldr	r6, =TEGRA_RESET_EXCEPTION_VECTOR
99	ldr	r5, =psci_cpu_entry
100	str	r5, [r6]
101
102	get_csr_reg r1, r2, r3
103
104	ldr	r6, =TEGRA_FLOW_CTRL_BASE
105	mov	r5, #(CSR_IMMEDIATE_WAKE | CSR_ENABLE)
106	str	r5, [r6, r2]
107
108	mov	r0, #ARM_PSCI_RET_SUCCESS	@ Return PSCI_RET_SUCCESS
109	pop	{pc}
110ENDPROC(psci_cpu_on)
111
112	.globl psci_text_end
113psci_text_end:
114	.popsection
115