xref: /openbmc/u-boot/arch/arm/mach-tegra/psci.S (revision e246b728)
1/* SPDX-License-Identifier: GPL-2.0+ */
2/*
3 * Copyright (C) 2014, NVIDIA
4 * Copyright (C) 2015, Siemens AG
5 *
6 * Authors:
7 *  Thierry Reding <treding@nvidia.com>
8 *  Jan Kiszka <jan.kiszka@siemens.com>
9 */
10
11#include <linux/linkage.h>
12#include <asm/macro.h>
13#include <asm/psci.h>
14
15	.pushsection ._secure.text, "ax"
16	.arch_extension sec
17
18#define TEGRA_SB_CSR_0			0x6000c200
19#define NS_RST_VEC_WR_DIS		(1 << 1)
20
21#define TEGRA_RESET_EXCEPTION_VECTOR	0x6000f100
22
23#define TEGRA_FLOW_CTRL_BASE		0x60007000
24#define FLOW_CTRL_CPU_CSR		0x08
25#define CSR_ENABLE			(1 << 0)
26#define CSR_IMMEDIATE_WAKE		(1 << 3)
27#define CSR_WAIT_WFI_SHIFT		8
28#define FLOW_CTRL_CPU1_CSR		0x18
29
30@ converts CPU ID into FLOW_CTRL_CPUn_CSR offset
31.macro get_csr_reg cpu, ofs, tmp
32	cmp	\cpu, #0		@ CPU0?
33	lsl	\tmp, \cpu, #3	@ multiple by 8 (register offset CPU1-3)
34	moveq	\ofs, #FLOW_CTRL_CPU_CSR
35	addne	\ofs, \tmp, #FLOW_CTRL_CPU1_CSR - 8
36.endm
37
38ENTRY(psci_arch_init)
39	mov	r6, lr
40
41	mrc	p15, 0, r5, c1, c1, 0	@ Read SCR
42	bic	r5, r5, #1		@ Secure mode
43	mcr	p15, 0, r5, c1, c1, 0	@ Write SCR
44	isb
45
46	@ lock reset vector for non-secure
47	ldr	r4, =TEGRA_SB_CSR_0
48	ldr	r5, [r4]
49	orr	r5, r5, #NS_RST_VEC_WR_DIS
50	str	r5, [r4]
51
52	bl	psci_get_cpu_id		@ CPU ID => r0
53
54	adr	r5, _sys_clock_freq
55	cmp	r0, #0
56
57	mrceq	p15, 0, r7, c14, c0, 0	@ read CNTFRQ from CPU0
58	streq	r7, [r5]
59
60	ldrne	r7, [r5]
61	mcrne	p15, 0, r7, c14, c0, 0	@ write CNTFRQ to CPU1..3
62
63	bx	r6
64ENDPROC(psci_arch_init)
65
66_sys_clock_freq:
67	.word	0
68
69ENTRY(psci_cpu_off)
70	bl	psci_cpu_off_common
71
72	bl	psci_get_cpu_id		@ CPU ID => r0
73
74	get_csr_reg r0, r2, r3
75
76	ldr	r6, =TEGRA_FLOW_CTRL_BASE
77	mov	r5, #(CSR_ENABLE)
78	mov	r4, #(1 << CSR_WAIT_WFI_SHIFT)
79	add	r5, r4, lsl r0
80	str	r5, [r6, r2]
81
82_loop:	wfi
83	b	_loop
84ENDPROC(psci_cpu_off)
85
86ENTRY(psci_cpu_on)
87	push	{r4, r5, r6, lr}
88
89	mov	r4, r1
90	mov	r0, r1
91	mov	r1, r2
92	mov	r2, r3
93	bl	psci_save		@ store target PC and context id
94	mov	r1, r4
95
96	ldr	r6, =TEGRA_RESET_EXCEPTION_VECTOR
97	ldr	r5, =psci_cpu_entry
98	str	r5, [r6]
99
100	get_csr_reg r1, r2, r3
101
102	ldr	r6, =TEGRA_FLOW_CTRL_BASE
103	mov	r5, #(CSR_IMMEDIATE_WAKE | CSR_ENABLE)
104	str	r5, [r6, r2]
105
106	mov	r0, #ARM_PSCI_RET_SUCCESS	@ Return PSCI_RET_SUCCESS
107	pop	{r4, r5, r6, pc}
108ENDPROC(psci_cpu_on)
109
110	.popsection
111