arch/arm/lib/psci-dt.c

   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 #ifdef CONFIG_ARMV8_SEC_FIRMWARE_SUPPORT
  14 #include <asm/armv8/sec_firmware.h>
  15 #endif
  16
  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 #ifdef CONFIG_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 #ifndef CONFIG_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 }