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/* Copyright (c) 2013, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that 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.
*/
/* Character device driver for memory mapped performance counter interface */
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/cpu_pm.h>
#include <linux/cpu.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/debugfs.h>
#include <linux/sched.h>
#include <linux/cdev.h>
uint32_t perfmap_base;
uint32_t PERF_BASE_SIZE;
static dev_t perfmap_dev;
static struct cdev perfmap_cdev;
static struct class *perfmap_devclass;
static struct of_device_id perfmap_of_device_ids[] = {
{.compatible = "qcom,perfmap"},
{},
};
static int perfmap_device_probe(struct platform_device *pdev)
{
struct resource *resource;
resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!resource)
return -EINVAL;
perfmap_base = resource->start;
return 0;
}
static struct platform_driver perfmap_pmu_driver = {
.driver = {
.name = "perfmap",
.of_match_table = perfmap_of_device_ids,
},
.probe = perfmap_device_probe,
};
static int perfmap_mmap(struct file *filep, struct vm_area_struct *vma)
{
int ret = 0;
unsigned long pfn_num;
pfn_num = perfmap_base>>PAGE_SHIFT;
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
if (remap_pfn_range(vma, vma->vm_start, pfn_num,
vma->vm_end-vma->vm_start,
vma->vm_page_prot)) {
return -EAGAIN;
}
return ret;
}
static const struct file_operations perfmap_fops = {
.mmap = perfmap_mmap,
};
static int perfmap_init(void)
{
int result = 0;
platform_driver_register(&perfmap_pmu_driver);
if (alloc_chrdev_region(&perfmap_dev, 0, 1, "perfmap") < 0) {
pr_err("perfmap: Error in alloc_chrdev_region\n");
goto alloc_err;
}
perfmap_devclass = class_create(THIS_MODULE, "chardrv");
if (IS_ERR(perfmap_devclass)) {
pr_err("perfmap: Error in class_create\n");
goto class_err;
}
if (device_create(perfmap_devclass, NULL, perfmap_dev, NULL,
"perfmap0") == NULL) {
pr_err("perfmap: Error in device_create\n");
goto create_err;
}
cdev_init(&perfmap_cdev, &perfmap_fops);
if (cdev_add(&perfmap_cdev, perfmap_dev, 1) == -1) {
pr_err("perfmap: Error in cdev_add\n");
goto add_err;
}
return result;
add_err:
device_destroy(perfmap_devclass, perfmap_dev);
create_err:
class_destroy(perfmap_devclass);
class_err:
unregister_chrdev_region(perfmap_dev, 1);
alloc_err:
result = -ENODEV;
return result;
}
static void perfmap_exit(void)
{
cdev_del(&perfmap_cdev);
device_destroy(perfmap_devclass, perfmap_dev);
class_destroy(perfmap_devclass);
unregister_chrdev_region(perfmap_dev, 1);
platform_driver_unregister(&perfmap_pmu_driver);
}
module_init(perfmap_init);
module_exit(perfmap_exit);
MODULE_LICENSE("GPL v2");
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