drivers/cpu_info/cpu_info.c

// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
/*
 * Copyright (c) 2019 Amlogic, Inc. All rights reserved.
 */

#include <linux/export.h>
#include <linux/cdev.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/uaccess.h>
#include <linux/sched.h>
#include <linux/platform_device.h>
#include <linux/amlogic/iomap.h>
#include <linux/amlogic/secmon.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/amlogic/cpu_info.h>
#include <linux/arm-smccc.h>
#include <linux/amlogic/cpu_version.h>
#ifdef CONFIG_AMLOGIC_SHOW_CPU_CHIPID
#include <linux/seq_file.h>
#include <linux/proc_fs.h>
#endif
#include <linux/upstream_version.h>

static unsigned char cpuinfo_chip_id[CHIPID_LEN];

void cpuinfo_get_chipid(unsigned char *cid, unsigned int size)
{
	memcpy(&cid[0], cpuinfo_chip_id, size);
}
EXPORT_SYMBOL(cpuinfo_get_chipid);

#ifdef CONFIG_AMLOGIC_SHOW_CPU_CHIPID
static int cpu_chipid_show(struct seq_file *m, void *arg)
{
	int i;

	seq_puts(m, "Serial:\t\t ");
	for (i = 0; i < CHIPID_LEN; i++)
		seq_printf(m, "%02x", cpuinfo_chip_id[i]);
	seq_puts(m, "\n");
	seq_printf(m, "Hardware:\t %s\n", "Amlogic");

	return 0;
}

static int cpu_chipid_open(struct inode *inode, struct file *file)
{
	return single_open(file, cpu_chipid_show, NULL);
}

static const struct proc_ops cpu_chipid_ops = {
	.proc_open	= cpu_chipid_open,
	.proc_read	= seq_read,
	.proc_lseek	= seq_lseek,
	.proc_release	= single_release,
};
#endif

static noinline int fn_smc(u64 function_id,
			   u64 arg0,
			   u64 arg1,
			   u64 arg2)
{
	struct arm_smccc_res res;

	arm_smccc_smc((unsigned long)function_id,
		      (unsigned long)arg0,
		      (unsigned long)arg1,
		      (unsigned long)arg2,
		      0, 0, 0, 0, &res);
	return res.a0;
}

static int cpuinfo_probe(struct platform_device *pdev)
{
	void __iomem *shm_out;
	struct device_node *np = pdev->dev.of_node;
	int cmd, ret, i;
#ifdef CONFIG_AMLOGIC_SHOW_CPU_CHIPID
	struct proc_dir_entry *proc;
#endif

	if (of_property_read_u32(np, "cpuinfo_cmd", &cmd))
		return -EINVAL;

	shm_out = get_meson_sm_output_base();
	if (!shm_out) {
		pr_err("failed to allocate shared memory\n");
		return -ENOMEM;
	}

	meson_sm_mutex_lock();
	ret = fn_smc(cmd, 2, 0, 0);
	if (ret == 0) {
		int version = *((unsigned int *)shm_out);

		if (version == 2) {
			memcpy((void *)&cpuinfo_chip_id[0],
			       (void *)shm_out + 4,
			       CHIPID_LEN);
		} else {
			pr_err("failed to get version\n");
			ret = -EINVAL;
		}
	} else {
		ret = -EPROTO;
	}
	meson_sm_mutex_unlock();

	if (ret == 0) {
		pr_info("serial = ");
		for (i = 0; i < CHIPID_LEN; i++)
			pr_cont("%02x", cpuinfo_chip_id[i]);
		pr_cont("\n");

#ifdef CONFIG_AMLOGIC_SHOW_CPU_CHIPID
		proc = proc_create("cpu_chipid", 0444, NULL, &cpu_chipid_ops);
		if (IS_ERR_OR_NULL(proc)) {
			pr_err("create cpu_chipid proc failed\n");
			return -EINVAL;
		}
#endif
	}

	return ret;
}

static const struct of_device_id cpuinfo_dt_match[] = {
	{ .compatible = "amlogic, cpuinfo" },
	{ /* sentinel */ }
};

static  struct platform_driver cpuinfo_platform_driver = {
	.probe		= cpuinfo_probe,
	.driver		= {
		.owner		= THIS_MODULE,
		.name		= "cpuinfo",
		.of_match_table	= cpuinfo_dt_match,
	},
};

static int __init meson_cpuinfo_init(void)
{
	pr_notice("build info: %s, common_drivers: %s\n", BUILD_TIME, COMMON_DRIVER_RELEASE);
	pr_notice("kernel upgrade info: <%d> <%s> <%s-%s>\n",
		  AML_KERNEL_VERSION, MERGE_DATE, UPSTREAM_VERSION, AML_PATCH_VERSION);

	meson_cpu_version_init();

	return  platform_driver_register(&cpuinfo_platform_driver);
}

#ifdef MODULE
module_init(meson_cpuinfo_init);
MODULE_LICENSE("GPL v2");
#else
subsys_initcall(meson_cpuinfo_init);
#endif