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 <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 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 }; 96