arch/arm/lib/psci-dt.c

   1 /*
   2  * Copyright 2016 NXP Semiconductor, Inc.
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0+
   5  */
   6
   7 #include <common.h>
   8 #include <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_ARMV8_PSCI) || defined(CONFIG_ARMV7_PSCI)
  20         int nodeoff;
  21         unsigned int psci_ver = 0;
  22         int tmp;
  23
  24         nodeoff = fdt_path_offset(fdt, "/cpus");
  25         if (nodeoff < 0) {
  26                 printf("couldn't find /cpus\n");
  27                 return nodeoff;
  28         }
  29
  30         /* add 'enable-method = "psci"' to each cpu node */
  31         for (tmp = fdt_first_subnode(fdt, nodeoff);
  32              tmp >= 0;
  33              tmp = fdt_next_subnode(fdt, tmp)) {
  34                 const struct fdt_property *prop;
  35                 int len;
  36
  37                 prop = fdt_get_property(fdt, tmp, "device_type", &len);
  38                 if (!prop)
  39                         continue;
  40                 if (len < 4)
  41                         continue;
  42                 if (strcmp(prop->data, "cpu"))
  43                         continue;
  44
  45                 /*
  46                  * Not checking rv here, our approach is to skip over errors in
  47                  * individual cpu nodes, hopefully some of the nodes are
  48                  * processed correctly and those will boot
  49                  */
  50                 fdt_setprop_string(fdt, tmp, "enable-method", "psci");
  51         }
  52
  53         nodeoff = fdt_path_offset(fdt, "/psci");
  54         if (nodeoff >= 0)
  55                 goto init_psci_node;
  56
  57         nodeoff = fdt_path_offset(fdt, "/");
  58         if (nodeoff < 0)
  59                 return nodeoff;
  60
  61         nodeoff = fdt_add_subnode(fdt, nodeoff, "psci");
  62         if (nodeoff < 0)
  63                 return nodeoff;
  64
  65 init_psci_node:
  66 #ifdef CONFIG_ARMV8_SEC_FIRMWARE_SUPPORT
  67         psci_ver = sec_firmware_support_psci_version();
  68 #endif
  69         switch (psci_ver) {
  70         case ARM_PSCI_VER_1_0:
  71                 tmp = fdt_setprop_string(fdt, nodeoff,
  72                                 "compatible", "arm,psci-1.0");
  73                 if (tmp)
  74                         return tmp;
  75         case ARM_PSCI_VER_0_2:
  76                 tmp = fdt_appendprop_string(fdt, nodeoff,
  77                                 "compatible", "arm,psci-0.2");
  78                 if (tmp)
  79                         return tmp;
  80         default:
  81         /*
  82          * The Secure firmware framework isn't able to support PSCI version 0.1.
  83          */
  84 #ifndef CONFIG_ARMV8_SEC_FIRMWARE_SUPPORT
  85                 tmp = fdt_appendprop_string(fdt, nodeoff,
  86                                 "compatible", "arm,psci");
  87                 if (tmp)
  88                         return tmp;
  89                 tmp = fdt_setprop_u32(fdt, nodeoff, "cpu_suspend",
  90                                 ARM_PSCI_FN_CPU_SUSPEND);
  91                 if (tmp)
  92                         return tmp;
  93                 tmp = fdt_setprop_u32(fdt, nodeoff, "cpu_off",
  94                                 ARM_PSCI_FN_CPU_OFF);
  95                 if (tmp)
  96                         return tmp;
  97                 tmp = fdt_setprop_u32(fdt, nodeoff, "cpu_on",
  98                                 ARM_PSCI_FN_CPU_ON);
  99                 if (tmp)
 100                         return tmp;
 101                 tmp = fdt_setprop_u32(fdt, nodeoff, "migrate",
 102                                 ARM_PSCI_FN_MIGRATE);
 103                 if (tmp)
 104                         return tmp;
 105 #endif
 106                 break;
 107         }
 108
 109         tmp = fdt_setprop_string(fdt, nodeoff, "method", "smc");
 110         if (tmp)
 111                 return tmp;
 112
 113 #endif
 114         return 0;
 115 }