drivers/firmware/psci.c

   1 /*
   2  * Copyright (C) 2017 Masahiro Yamada <yamada.masahiro@socionext.com>
   3  *
   4  * Based on drivers/firmware/psci.c from Linux:
   5  * Copyright (C) 2015 ARM Limited
   6  *
   7  * SPDX-License-Identifier:     GPL-2.0+
   8  */
   9
  10 #include <common.h>
  11 #include <dm.h>
  12 #include <dm/lists.h>
  13 #include <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 psci_fn *invoke_psci_fn;
  20
  21 static unsigned long __invoke_psci_fn_hvc(unsigned long function_id,
  22                         unsigned long arg0, unsigned long arg1,
  23                         unsigned long arg2)
  24 {
  25         struct arm_smccc_res res;
  26
  27         arm_smccc_hvc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
  28         return res.a0;
  29 }
  30
  31 static unsigned long __invoke_psci_fn_smc(unsigned long function_id,
  32                         unsigned long arg0, unsigned long arg1,
  33                         unsigned long arg2)
  34 {
  35         struct arm_smccc_res res;
  36
  37         arm_smccc_smc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
  38         return res.a0;
  39 }
  40
  41 static int psci_bind(struct udevice *dev)
  42 {
  43         /* No SYSTEM_RESET support for PSCI 0.1 */
  44         if (device_is_compatible(dev, "arm,psci-0.2") ||
  45             device_is_compatible(dev, "arm,psci-1.0")) {
  46                 int ret;
  47
  48                 /* bind psci-sysreset optionally */
  49                 ret = device_bind_driver(dev, "psci-sysreset", "psci-sysreset",
  50                                          NULL);
  51                 if (ret)
  52                         pr_debug("PSCI System Reset was not bound.\n");
  53         }
  54
  55         return 0;
  56 }
  57
  58 static int psci_probe(struct udevice *dev)
  59 {
  60         DECLARE_GLOBAL_DATA_PTR;
  61         const char *method;
  62
  63         method = fdt_stringlist_get(gd->fdt_blob, dev_of_offset(dev), "method",
  64                                     0, NULL);
  65         if (!method) {
  66                 pr_warn("missing \"method\" property\n");
  67                 return -ENXIO;
  68         }
  69
  70         if (!strcmp("hvc", method)) {
  71                 invoke_psci_fn = __invoke_psci_fn_hvc;
  72         } else if (!strcmp("smc", method)) {
  73                 invoke_psci_fn = __invoke_psci_fn_smc;
  74         } else {
  75                 pr_warn("invalid \"method\" property: %s\n", method);
  76                 return -EINVAL;
  77         }
  78
  79         return 0;
  80 }
  81
  82 static const struct udevice_id psci_of_match[] = {
  83         { .compatible = "arm,psci" },
  84         { .compatible = "arm,psci-0.2" },
  85         { .compatible = "arm,psci-1.0" },
  86         {},
  87 };
  88
  89 U_BOOT_DRIVER(psci) = {
  90         .name = "psci",
  91         .id = UCLASS_FIRMWARE,
  92         .of_match = psci_of_match,
  93         .bind = psci_bind,
  94         .probe = psci_probe,
  95 };