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/*
* Copyright (c) 2019, NVIDIA CORPORATION. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*/
#include <linux/cpu.h>
#include <linux/module.h>
#include <linux/platform/tegra/tegra18_cpu_map.h>
#include <linux/platform/tegra/tegra-cpu.h>
#include <linux/cpuhotplug.h>
enum cputype_t {
INVALID = 0x00,
CARMEL = 0x1,
DENVER,
A57,
OTHERS,
CPUTYPE_MAX = OTHERS + 1,
CPUTYPE_FORCE_U32 = 0xFFFFFFFF
};
static struct kobject *tegra_cpu_type;
static struct kobject *tegra_cpu[CPUTYPE_MAX];
static enum cputype_t cpu_to_type[NR_CPUS];
static enum cpuhp_state assigned_cpu_state;
static struct kobject *create_dir(const char *name, struct kobject *parent)
{
pr_debug("%s: about to create %s with parent %s\n",
__func__, name, kobject_name(parent));
return kobject_create_and_add(name, parent);
}
static void remove_dir(struct kobject *obj)
{
if (!obj)
return;
pr_debug("%s: removing %s\n", __func__, kobject_name(obj));
kobject_put(obj);
}
static int tegra_cpu_prepare_down(unsigned int cpu)
{
char name[8];
int i;
enum cputype_t cpu_type;
pr_debug("%s: cpu = %d\n", __func__, cpu);
cpu_type = cpu_to_type[cpu];
if (!tegra_cpu[cpu_type])
return -ENODEV;
snprintf(name, sizeof(name), "cpu%d", cpu);
sysfs_remove_link(tegra_cpu[cpu_type], name);
cpu_to_type[cpu] = INVALID;
for_each_possible_cpu(i) {
if (cpu_to_type[i] == cpu_type)
return 0;
}
remove_dir(tegra_cpu[cpu_type]);
return 0;
}
static int tegra_cpu_online(unsigned int cpu)
{
struct device *target;
enum cputype_t cpu_type;
char *cpu_type_str;
int ret;
pr_debug("%s: cpu = %d\n", __func__, cpu);
target = get_cpu_device(cpu);
if (!target)
return -ENODEV;
if (tegra_is_cpu_carmel(cpu)) {
cpu_type = CARMEL;
cpu_type_str = "carmel";
} else if (tegra18_is_cpu_denver(cpu)) {
cpu_type = DENVER;
cpu_type_str = "denver";
} else if (tegra18_is_cpu_arm(cpu)) {
cpu_type = A57;
cpu_type_str = "a57";
} else {
cpu_type = OTHERS;
cpu_type_str = "others";
}
if (!tegra_cpu[cpu_type]) {
tegra_cpu[cpu_type] = create_dir(cpu_type_str, tegra_cpu_type);
if (tegra_cpu[cpu_type] == NULL)
return -ENOMEM;
}
ret = sysfs_create_link(tegra_cpu[cpu_type],
&target->kobj, dev_name(target));
if (ret)
return ret;
cpu_to_type[cpu] = cpu_type;
return 0;
}
static int __init tegra_cpu_sysfs_init(void)
{
int ret = -ENOMEM;
tegra_cpu_type = create_dir("tegra_cpu_type",
get_cpu_device(smp_processor_id())->kobj.parent);
if (!tegra_cpu_type)
goto err;
ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
"cpu/tegra_cpu_sysfs:online", tegra_cpu_online, tegra_cpu_prepare_down);
if (ret < 0) {
remove_dir(tegra_cpu_type);
goto err;
}
assigned_cpu_state = ret;
ret = 0;
err:
return ret;
}
module_init(tegra_cpu_sysfs_init);
static void __exit tegra_cpu_sysfs_exit(void)
{
cpuhp_remove_state(assigned_cpu_state);
remove_dir(tegra_cpu_type);
}
module_exit(tegra_cpu_sysfs_exit);
MODULE_AUTHOR("Achal Verma <achalv@nvidia.com>");
MODULE_DESCRIPTION("Tegra CPU Topology sysfs");
MODULE_LICENSE("GPL v2");
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