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
32static struct soc_device *soc_dev;
33static struct soc_device_attribute *soc_dev_attr;
34
35static int __init smccc_soc_init(void)
36{
37 int soc_id_rev, soc_id_version;
38 static char soc_id_str[20], soc_id_rev_str[12];
39 static char soc_id_jep106_id_str[12];
40
41 if (arm_smccc_get_version() < ARM_SMCCC_VERSION_1_2)
42 return 0;
43
44 soc_id_version = arm_smccc_get_soc_id_version();
45 if (soc_id_version == SMCCC_RET_NOT_SUPPORTED) {
46 pr_info("ARCH_SOC_ID not implemented, skipping ....\n");
47 return 0;
48 }
49
50 if (soc_id_version < 0) {
51 pr_err("Invalid SoC Version: %x\n", soc_id_version);
52 return -EINVAL;
53 }
54
55 soc_id_rev = arm_smccc_get_soc_id_revision();
56 if (soc_id_rev < 0) {
57 pr_err("Invalid SoC Revision: %x\n", soc_id_rev);
58 return -EINVAL;
59 }
60
61 soc_dev_attr = kzalloc(size: sizeof(*soc_dev_attr), GFP_KERNEL);
62 if (!soc_dev_attr)
63 return -ENOMEM;
64
65 sprintf(buf: soc_id_rev_str, fmt: "0x%08x", soc_id_rev);
66 sprintf(buf: soc_id_jep106_id_str, fmt: "jep106:%02x%02x",
67 JEP106_BANK_CONT_CODE(soc_id_version),
68 JEP106_ID_CODE(soc_id_version));
69 sprintf(buf: soc_id_str, fmt: "%s:%04x", soc_id_jep106_id_str,
70 IMP_DEF_SOC_ID(soc_id_version));
71
72 soc_dev_attr->soc_id = soc_id_str;
73 soc_dev_attr->revision = soc_id_rev_str;
74 soc_dev_attr->family = soc_id_jep106_id_str;
75
76 soc_dev = soc_device_register(soc_plat_dev_attr: soc_dev_attr);
77 if (IS_ERR(ptr: soc_dev)) {
78 kfree(objp: soc_dev_attr);
79 return PTR_ERR(ptr: soc_dev);
80 }
81
82 pr_info("ID = %s Revision = %s\n", soc_dev_attr->soc_id,
83 soc_dev_attr->revision);
84
85 return 0;
86}
87module_init(smccc_soc_init);
88
89static void __exit smccc_soc_exit(void)
90{
91 if (soc_dev)
92 soc_device_unregister(soc_dev);
93 kfree(objp: soc_dev_attr);
94}
95module_exit(smccc_soc_exit);
96

source code of linux/drivers/firmware/smccc/soc_id.c