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
smccc_soc_init(void)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
smccc_soc_exit(void)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