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path: root/drivers/firmware/smccc/soc_id.c
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Diffstat (limited to 'drivers/firmware/smccc/soc_id.c')
-rw-r--r--drivers/firmware/smccc/soc_id.c95
1 files changed, 95 insertions, 0 deletions
diff --git a/drivers/firmware/smccc/soc_id.c b/drivers/firmware/smccc/soc_id.c
new file mode 100644
index 0000000000..1990263fbb
--- /dev/null
+++ b/drivers/firmware/smccc/soc_id.c
@@ -0,0 +1,95 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2020 Arm Limited
+ */
+
+#define pr_fmt(fmt) "SMCCC: SOC_ID: " fmt
+
+#include <linux/arm-smccc.h>
+#include <linux/bitfield.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/sys_soc.h>
+
+#define SMCCC_SOC_ID_JEP106_BANK_IDX_MASK GENMASK(30, 24)
+/*
+ * As per the SMC Calling Convention specification v1.2 (ARM DEN 0028C)
+ * Section 7.4 SMCCC_ARCH_SOC_ID bits[23:16] are JEP-106 identification
+ * code with parity bit for the SiP. We can drop the parity bit.
+ */
+#define SMCCC_SOC_ID_JEP106_ID_CODE_MASK GENMASK(22, 16)
+#define SMCCC_SOC_ID_IMP_DEF_SOC_ID_MASK GENMASK(15, 0)
+
+#define JEP106_BANK_CONT_CODE(x) \
+ (u8)(FIELD_GET(SMCCC_SOC_ID_JEP106_BANK_IDX_MASK, (x)))
+#define JEP106_ID_CODE(x) \
+ (u8)(FIELD_GET(SMCCC_SOC_ID_JEP106_ID_CODE_MASK, (x)))
+#define IMP_DEF_SOC_ID(x) \
+ (u16)(FIELD_GET(SMCCC_SOC_ID_IMP_DEF_SOC_ID_MASK, (x)))
+
+static struct soc_device *soc_dev;
+static struct soc_device_attribute *soc_dev_attr;
+
+static int __init smccc_soc_init(void)
+{
+ int soc_id_rev, soc_id_version;
+ static char soc_id_str[20], soc_id_rev_str[12];
+ static char soc_id_jep106_id_str[12];
+
+ if (arm_smccc_get_version() < ARM_SMCCC_VERSION_1_2)
+ return 0;
+
+ soc_id_version = arm_smccc_get_soc_id_version();
+ if (soc_id_version == SMCCC_RET_NOT_SUPPORTED) {
+ pr_info("ARCH_SOC_ID not implemented, skipping ....\n");
+ return 0;
+ }
+
+ if (soc_id_version < 0) {
+ pr_err("Invalid SoC Version: %x\n", soc_id_version);
+ return -EINVAL;
+ }
+
+ soc_id_rev = arm_smccc_get_soc_id_revision();
+ if (soc_id_rev < 0) {
+ pr_err("Invalid SoC Revision: %x\n", soc_id_rev);
+ return -EINVAL;
+ }
+
+ soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
+ if (!soc_dev_attr)
+ return -ENOMEM;
+
+ sprintf(soc_id_rev_str, "0x%08x", soc_id_rev);
+ sprintf(soc_id_jep106_id_str, "jep106:%02x%02x",
+ JEP106_BANK_CONT_CODE(soc_id_version),
+ JEP106_ID_CODE(soc_id_version));
+ sprintf(soc_id_str, "%s:%04x", soc_id_jep106_id_str,
+ IMP_DEF_SOC_ID(soc_id_version));
+
+ soc_dev_attr->soc_id = soc_id_str;
+ soc_dev_attr->revision = soc_id_rev_str;
+ soc_dev_attr->family = soc_id_jep106_id_str;
+
+ soc_dev = soc_device_register(soc_dev_attr);
+ if (IS_ERR(soc_dev)) {
+ kfree(soc_dev_attr);
+ return PTR_ERR(soc_dev);
+ }
+
+ pr_info("ID = %s Revision = %s\n", soc_dev_attr->soc_id,
+ soc_dev_attr->revision);
+
+ return 0;
+}
+module_init(smccc_soc_init);
+
+static void __exit smccc_soc_exit(void)
+{
+ if (soc_dev)
+ soc_device_unregister(soc_dev);
+ kfree(soc_dev_attr);
+}
+module_exit(smccc_soc_exit);