drivers/firmware/smccc/soc_id.c

   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         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
  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);