toaruos/kernel/vfs/portio.c

82 lines
1.8 KiB
C

/**
* @file kernel/vfs/portio.c
* @brief File-based interface to x86 CPU port I/O.
*
* Provides a seek/read/write interface to x86 ports at /dev/port
*
* @copyright
* This file is part of ToaruOS and is released under the terms
* of the NCSA / University of Illinois License - see LICENSE.md
* Copyright (C) 2018-2021 K. Lange
*/
#include <kernel/process.h>
#include <kernel/vfs.h>
#include <kernel/string.h>
#include <kernel/arch/x86_64/ports.h>
static ssize_t read_port(fs_node_t *node, off_t offset, size_t size, uint8_t *buffer) {
switch (size) {
case 1:
buffer[0] = inportb(offset);
break;
case 2:
((uint16_t *)buffer)[0] = inports(offset);
break;
case 4:
((uint32_t *)buffer)[0] = inportl(offset);
break;
default:
for (unsigned int i = 0; i < size; ++i) {
buffer[i] = inportb(offset + i);
}
break;
}
return size;
}
static ssize_t write_port(fs_node_t *node, off_t offset, size_t size, uint8_t *buffer) {
switch (size) {
case 1:
outportb(offset, buffer[0]);
break;
case 2:
outports(offset, ((uint16_t*)buffer)[0]);
break;
case 4:
outportl(offset, ((uint32_t*)buffer)[0]);
break;
default:
for (unsigned int i = 0; i < size; ++i) {
outportb(offset +i, buffer[i]);
}
break;
}
return size;
}
static fs_node_t * port_device_create(void) {
fs_node_t * fnode = malloc(sizeof(fs_node_t));
memset(fnode, 0x00, sizeof(fs_node_t));
fnode->inode = 0;
strcpy(fnode->name, "port");
fnode->uid = 0;
fnode->gid = 0;
fnode->mask = 0660;
fnode->flags = FS_BLOCKDEVICE;
fnode->read = read_port;
fnode->write = write_port;
fnode->open = NULL;
fnode->close = NULL;
fnode->readdir = NULL;
fnode->finddir = NULL;
fnode->ioctl = NULL;
return fnode;
}
void portio_initialize(void) {
vfs_mount("/dev/port", port_device_create());
}