1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright 2020 Arm Limited 4 */ 5 6 #define pr_fmt(fmt) "SMCCC: SOC_ID: " fmt 7 8 #include <linux/arm-smccc.h> 9 #include <linux/bitfield.h> 10 #include <linux/device.h> 11 #include <linux/module.h> 12 #include <linux/kernel.h> 13 #include <linux/slab.h> 14 #include <linux/sys_soc.h> 15 16 #define SMCCC_SOC_ID_JEP106_BANK_IDX_MASK GENMASK(30, 24) 17 /* 18 * As per the SMC Calling Convention specification v1.2 (ARM DEN 0028C) 19 * Section 7.4 SMCCC_ARCH_SOC_ID bits[23:16] are JEP-106 identification 20 * code with parity bit for the SiP. We can drop the parity bit. 21 */ 22 #define SMCCC_SOC_ID_JEP106_ID_CODE_MASK GENMASK(22, 16) 23 #define SMCCC_SOC_ID_IMP_DEF_SOC_ID_MASK GENMASK(15, 0) 24 25 #define JEP106_BANK_CONT_CODE(x) \ 26 (u8)(FIELD_GET(SMCCC_SOC_ID_JEP106_BANK_IDX_MASK, (x))) 27 #define JEP106_ID_CODE(x) \ 28 (u8)(FIELD_GET(SMCCC_SOC_ID_JEP106_ID_CODE_MASK, (x))) 29 #define IMP_DEF_SOC_ID(x) \ 30 (u16)(FIELD_GET(SMCCC_SOC_ID_IMP_DEF_SOC_ID_MASK, (x))) 31 32 static struct soc_device *soc_dev; 33 static struct soc_device_attribute *soc_dev_attr; 34 35 static int __init smccc_soc_init(void) 36 { 37 struct arm_smccc_res res; 38 int soc_id_rev, soc_id_version; 39 static char soc_id_str[20], soc_id_rev_str[12]; 40 static char soc_id_jep106_id_str[12]; 41 42 if (arm_smccc_get_version() < ARM_SMCCC_VERSION_1_2) 43 return 0; 44 45 if (arm_smccc_1_1_get_conduit() == SMCCC_CONDUIT_NONE) { 46 pr_err("%s: invalid SMCCC conduit\n", __func__); 47 return -EOPNOTSUPP; 48 } 49 50 arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, 51 ARM_SMCCC_ARCH_SOC_ID, &res); 52 53 if ((int)res.a0 == SMCCC_RET_NOT_SUPPORTED) { 54 pr_info("ARCH_SOC_ID not implemented, skipping ....\n"); 55 return 0; 56 } 57 58 if ((int)res.a0 < 0) { 59 pr_info("ARCH_FEATURES(ARCH_SOC_ID) returned error: %lx\n", 60 res.a0); 61 return -EINVAL; 62 } 63 64 arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_SOC_ID, 0, &res); 65 if ((int)res.a0 < 0) { 66 pr_err("ARCH_SOC_ID(0) returned error: %lx\n", res.a0); 67 return -EINVAL; 68 } 69 70 soc_id_version = res.a0; 71 72 arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_SOC_ID, 1, &res); 73 if ((int)res.a0 < 0) { 74 pr_err("ARCH_SOC_ID(1) returned error: %lx\n", res.a0); 75 return -EINVAL; 76 } 77 78 soc_id_rev = res.a0; 79 80 soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL); 81 if (!soc_dev_attr) 82 return -ENOMEM; 83 84 sprintf(soc_id_rev_str, "0x%08x", soc_id_rev); 85 sprintf(soc_id_jep106_id_str, "jep106:%02x%02x", 86 JEP106_BANK_CONT_CODE(soc_id_version), 87 JEP106_ID_CODE(soc_id_version)); 88 sprintf(soc_id_str, "%s:%04x", soc_id_jep106_id_str, 89 IMP_DEF_SOC_ID(soc_id_version)); 90 91 soc_dev_attr->soc_id = soc_id_str; 92 soc_dev_attr->revision = soc_id_rev_str; 93 soc_dev_attr->family = soc_id_jep106_id_str; 94 95 soc_dev = soc_device_register(soc_dev_attr); 96 if (IS_ERR(soc_dev)) { 97 kfree(soc_dev_attr); 98 return PTR_ERR(soc_dev); 99 } 100 101 pr_info("ID = %s Revision = %s\n", soc_dev_attr->soc_id, 102 soc_dev_attr->revision); 103 104 return 0; 105 } 106 module_init(smccc_soc_init); 107 108 static void __exit smccc_soc_exit(void) 109 { 110 if (soc_dev) 111 soc_device_unregister(soc_dev); 112 kfree(soc_dev_attr); 113 } 114 module_exit(smccc_soc_exit); 115