openharmony_kernel_liteos_a/drivers/char/mem/src/mem.c

102 lines
3.2 KiB
C

/*
* Copyright (c) 2013-2019 Huawei Technologies Co., Ltd. All rights reserved.
* Copyright (c) 2020-2021 Huawei Device Co., Ltd. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this list of
* conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice, this list
* of conditions and the following disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* 3. Neither the name of the copyright holder nor the names of its contributors may be used
* to endorse or promote products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "fcntl.h"
#include "linux/kernel.h"
#include "fs/driver.h"
static int MemOpen(struct file *filep)
{
return 0;
}
static int MemClose(struct file *filep)
{
return 0;
}
static ssize_t MemRead(struct file *filep, char *buffer, size_t buflen)
{
return 0;
}
static ssize_t MemWrite(struct file *filep, const char *buffer, size_t buflen)
{
return 0;
}
static ssize_t MemMap(struct file *filep, LosVmMapRegion *region)
{
#ifdef LOSCFG_KERNEL_VM
size_t size = region->range.size;
PADDR_T paddr = region->pgOff << PAGE_SHIFT;
VADDR_T vaddr = region->range.base;
LosVmSpace *space = LOS_SpaceGet(vaddr);
if (((paddr + size) >= SYS_MEM_BASE) && (paddr < SYS_MEM_END)) {
return -EINVAL;
}
/* Peripheral register memory adds strongly ordered attributes */
region->regionFlags |= VM_MAP_REGION_FLAG_STRONGLY_ORDERED;
if (space == NULL) {
return -EAGAIN;
}
if (LOS_ArchMmuMap(&space->archMmu, vaddr, paddr, size >> PAGE_SHIFT, region->regionFlags) <= 0) {
return -EAGAIN;
}
#else
UNUSED(filep);
UNUSED(region);
#endif
return 0;
}
static const struct file_operations_vfs g_memDevOps = {
MemOpen, /* open */
MemClose, /* close */
MemRead, /* read */
MemWrite, /* write */
NULL, /* seek */
NULL, /* ioctl */
MemMap, /* mmap */
#ifndef CONFIG_DISABLE_POLL
NULL, /* poll */
#endif
NULL, /* unlink */
};
int DevMemRegister(void)
{
return register_driver("/dev/mem", &g_memDevOps, 0644, 0); /* 0644: file mode */
}