1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2017 Masahiro Yamada <yamada.masahiro@socionext.com>
4  *
5  * Based on drivers/firmware/psci.c from Linux:
6  * Copyright (C) 2015 ARM Limited
7  */
8 
9 #include <common.h>
10 #include <dm.h>
11 #include <dm/lists.h>
12 #include <efi_loader.h>
13 #include <linux/libfdt.h>
14 #include <linux/arm-smccc.h>
15 #include <linux/errno.h>
16 #include <linux/printk.h>
17 #include <linux/psci.h>
18 
19 #define DRIVER_NAME "psci"
20 
21 #define PSCI_METHOD_HVC 1
22 #define PSCI_METHOD_SMC 2
23 
24 int __efi_runtime_data psci_method;
25 
invoke_psci_fn(unsigned long function_id,unsigned long arg0,unsigned long arg1,unsigned long arg2)26 unsigned long __efi_runtime invoke_psci_fn
27 		(unsigned long function_id, unsigned long arg0,
28 		 unsigned long arg1, unsigned long arg2)
29 {
30 	struct arm_smccc_res res;
31 
32 	/*
33 	 * In the __efi_runtime we need to avoid the switch statement. In some
34 	 * cases the compiler creates lookup tables to implement switch. These
35 	 * tables are not correctly relocated when SetVirtualAddressMap is
36 	 * called.
37 	 */
38 	if (psci_method == PSCI_METHOD_SMC)
39 		arm_smccc_smc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
40 	else if (psci_method == PSCI_METHOD_HVC)
41 		arm_smccc_hvc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
42 	else
43 		res.a0 = PSCI_RET_DISABLED;
44 	return res.a0;
45 }
46 
psci_bind(struct udevice * dev)47 static int psci_bind(struct udevice *dev)
48 {
49 	/* No SYSTEM_RESET support for PSCI 0.1 */
50 	if (device_is_compatible(dev, "arm,psci-0.2") ||
51 	    device_is_compatible(dev, "arm,psci-1.0")) {
52 		int ret;
53 
54 		/* bind psci-sysreset optionally */
55 		ret = device_bind_driver(dev, "psci-sysreset", "psci-sysreset",
56 					 NULL);
57 		if (ret)
58 			pr_debug("PSCI System Reset was not bound.\n");
59 	}
60 
61 	return 0;
62 }
63 
psci_probe(struct udevice * dev)64 static int psci_probe(struct udevice *dev)
65 {
66 	DECLARE_GLOBAL_DATA_PTR;
67 	const char *method;
68 
69 	method = fdt_stringlist_get(gd->fdt_blob, dev_of_offset(dev), "method",
70 				    0, NULL);
71 	if (!method) {
72 		pr_warn("missing \"method\" property\n");
73 		return -ENXIO;
74 	}
75 
76 	if (!strcmp("hvc", method)) {
77 		psci_method = PSCI_METHOD_HVC;
78 	} else if (!strcmp("smc", method)) {
79 		psci_method = PSCI_METHOD_SMC;
80 	} else {
81 		pr_warn("invalid \"method\" property: %s\n", method);
82 		return -EINVAL;
83 	}
84 
85 	return 0;
86 }
87 
88 /**
89  * void do_psci_probe() - probe PSCI firmware driver
90  *
91  * Ensure that psci_method is initialized.
92  */
do_psci_probe(void)93 static void __maybe_unused do_psci_probe(void)
94 {
95 	struct udevice *dev;
96 
97 	uclass_get_device_by_name(UCLASS_FIRMWARE, DRIVER_NAME, &dev);
98 }
99 
100 #if IS_ENABLED(CONFIG_EFI_LOADER) && IS_ENABLED(CONFIG_PSCI_RESET)
efi_reset_system_init(void)101 efi_status_t efi_reset_system_init(void)
102 {
103 	do_psci_probe();
104 	return EFI_SUCCESS;
105 }
106 
efi_reset_system(enum efi_reset_type reset_type,efi_status_t reset_status,unsigned long data_size,void * reset_data)107 void __efi_runtime EFIAPI efi_reset_system(enum efi_reset_type reset_type,
108 					   efi_status_t reset_status,
109 					   unsigned long data_size,
110 					   void *reset_data)
111 {
112 	if (reset_type == EFI_RESET_COLD ||
113 	    reset_type == EFI_RESET_WARM ||
114 	    reset_type == EFI_RESET_PLATFORM_SPECIFIC) {
115 		invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
116 	} else if (reset_type == EFI_RESET_SHUTDOWN) {
117 		invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
118 	}
119 	while (1)
120 		;
121 }
122 #endif /* IS_ENABLED(CONFIG_EFI_LOADER) && IS_ENABLED(CONFIG_PSCI_RESET) */
123 
124 #ifdef CONFIG_PSCI_RESET
reset_misc(void)125 void reset_misc(void)
126 {
127 	do_psci_probe();
128 	invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
129 }
130 #endif /* CONFIG_PSCI_RESET */
131 
132 #ifdef CONFIG_CMD_POWEROFF
do_poweroff(cmd_tbl_t * cmdtp,int flag,int argc,char * const argv[])133 int do_poweroff(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
134 {
135 	do_psci_probe();
136 
137 	puts("poweroff ...\n");
138 	udelay(50000); /* wait 50 ms */
139 
140 	disable_interrupts();
141 	invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
142 	enable_interrupts();
143 
144 	log_err("Power off not supported on this platform\n");
145 	return CMD_RET_FAILURE;
146 }
147 #endif
148 
149 static const struct udevice_id psci_of_match[] = {
150 	{ .compatible = "arm,psci" },
151 	{ .compatible = "arm,psci-0.2" },
152 	{ .compatible = "arm,psci-1.0" },
153 	{},
154 };
155 
156 U_BOOT_DRIVER(psci) = {
157 	.name = DRIVER_NAME,
158 	.id = UCLASS_FIRMWARE,
159 	.of_match = psci_of_match,
160 	.bind = psci_bind,
161 	.probe = psci_probe,
162 };
163