1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright 2016 NXP Semiconductor, Inc.
4  */
5 
6 #include <common.h>
7 #include <asm/cache.h>
8 #include <linux/libfdt.h>
9 #include <fdt_support.h>
10 #include <linux/sizes.h>
11 #include <linux/kernel.h>
12 #include <asm/psci.h>
13 #if CONFIG_IS_ENABLED(ARMV8_SEC_FIRMWARE_SUPPORT)
14 #include <asm/armv8/sec_firmware.h>
15 #endif
16 
fdt_psci(void * fdt)17 int fdt_psci(void *fdt)
18 {
19 #if defined(CONFIG_ARMV7_PSCI) || defined(CONFIG_ARMV8_PSCI) || \
20 	defined(CONFIG_SEC_FIRMWARE_ARMV8_PSCI)
21 	int nodeoff;
22 	unsigned int psci_ver = 0;
23 	int tmp;
24 
25 	nodeoff = fdt_path_offset(fdt, "/cpus");
26 	if (nodeoff < 0) {
27 		printf("couldn't find /cpus\n");
28 		return nodeoff;
29 	}
30 
31 	/* add 'enable-method = "psci"' to each cpu node */
32 	for (tmp = fdt_first_subnode(fdt, nodeoff);
33 	     tmp >= 0;
34 	     tmp = fdt_next_subnode(fdt, tmp)) {
35 		const struct fdt_property *prop;
36 		int len;
37 
38 		prop = fdt_get_property(fdt, tmp, "device_type", &len);
39 		if (!prop)
40 			continue;
41 		if (len < 4)
42 			continue;
43 		if (strcmp(prop->data, "cpu"))
44 			continue;
45 
46 		/*
47 		 * Not checking rv here, our approach is to skip over errors in
48 		 * individual cpu nodes, hopefully some of the nodes are
49 		 * processed correctly and those will boot
50 		 */
51 		fdt_setprop_string(fdt, tmp, "enable-method", "psci");
52 	}
53 
54 	nodeoff = fdt_path_offset(fdt, "/psci");
55 	if (nodeoff >= 0)
56 		goto init_psci_node;
57 
58 	nodeoff = fdt_path_offset(fdt, "/");
59 	if (nodeoff < 0)
60 		return nodeoff;
61 
62 	nodeoff = fdt_add_subnode(fdt, nodeoff, "psci");
63 	if (nodeoff < 0)
64 		return nodeoff;
65 
66 init_psci_node:
67 #if CONFIG_IS_ENABLED(ARMV8_SEC_FIRMWARE_SUPPORT)
68 	psci_ver = sec_firmware_support_psci_version();
69 #elif defined(CONFIG_ARMV7_PSCI_1_0) || defined(CONFIG_ARMV8_PSCI)
70 	psci_ver = ARM_PSCI_VER_1_0;
71 #elif defined(CONFIG_ARMV7_PSCI_0_2)
72 	psci_ver = ARM_PSCI_VER_0_2;
73 #endif
74 	if (psci_ver >= ARM_PSCI_VER_1_0) {
75 		tmp = fdt_setprop_string(fdt, nodeoff,
76 				"compatible", "arm,psci-1.0");
77 		if (tmp)
78 			return tmp;
79 	}
80 
81 	if (psci_ver >= ARM_PSCI_VER_0_2) {
82 		tmp = fdt_appendprop_string(fdt, nodeoff,
83 				"compatible", "arm,psci-0.2");
84 		if (tmp)
85 			return tmp;
86 	}
87 
88 #if !CONFIG_IS_ENABLED(ARMV8_SEC_FIRMWARE_SUPPORT)
89 	/*
90 	 * The Secure firmware framework isn't able to support PSCI version 0.1.
91 	 */
92 	if (psci_ver < ARM_PSCI_VER_0_2) {
93 		tmp = fdt_appendprop_string(fdt, nodeoff,
94 				"compatible", "arm,psci");
95 		if (tmp)
96 			return tmp;
97 		tmp = fdt_setprop_u32(fdt, nodeoff, "cpu_suspend",
98 				ARM_PSCI_FN_CPU_SUSPEND);
99 		if (tmp)
100 			return tmp;
101 		tmp = fdt_setprop_u32(fdt, nodeoff, "cpu_off",
102 				ARM_PSCI_FN_CPU_OFF);
103 		if (tmp)
104 			return tmp;
105 		tmp = fdt_setprop_u32(fdt, nodeoff, "cpu_on",
106 				ARM_PSCI_FN_CPU_ON);
107 		if (tmp)
108 			return tmp;
109 		tmp = fdt_setprop_u32(fdt, nodeoff, "migrate",
110 				ARM_PSCI_FN_MIGRATE);
111 		if (tmp)
112 			return tmp;
113 	}
114 #endif
115 
116 	tmp = fdt_setprop_string(fdt, nodeoff, "method", "smc");
117 	if (tmp)
118 		return tmp;
119 
120 	tmp = fdt_setprop_string(fdt, nodeoff, "status", "okay");
121 	if (tmp)
122 		return tmp;
123 
124 #endif
125 	return 0;
126 }
127