xref: /openbmc/linux/drivers/firmware/smccc/soc_id.c (revision d05799d7)
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 	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(sizeof(*soc_dev_attr), GFP_KERNEL);
62 	if (!soc_dev_attr)
63 		return -ENOMEM;
64 
65 	sprintf(soc_id_rev_str, "0x%08x", soc_id_rev);
66 	sprintf(soc_id_jep106_id_str, "jep106:%02x%02x",
67 		JEP106_BANK_CONT_CODE(soc_id_version),
68 		JEP106_ID_CODE(soc_id_version));
69 	sprintf(soc_id_str, "%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_dev_attr);
77 	if (IS_ERR(soc_dev)) {
78 		kfree(soc_dev_attr);
79 		return PTR_ERR(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 }
87 module_init(smccc_soc_init);
88 
smccc_soc_exit(void)89 static void __exit smccc_soc_exit(void)
90 {
91 	if (soc_dev)
92 		soc_device_unregister(soc_dev);
93 	kfree(soc_dev_attr);
94 }
95 module_exit(smccc_soc_exit);
96