Files
lk/platform/pc/cmos.c
2022-01-09 18:20:14 -08:00

45 lines
1.5 KiB
C

/*
* Copyright (c) 2019 Travis Geiselbrecht
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files
* (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge,
* publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include <platform/cmos.h>
#include <lk/trace.h>
#include <lk/debug.h>
#include <kernel/spinlock.h>
#include <platform/pc.h>
static spin_lock_t lock = SPIN_LOCK_INITIAL_VALUE;
uint8_t cmos_read(uint8_t reg) {
spin_lock_saved_state_t state;
spin_lock_irqsave(&lock, state);
outp(CMOS_CONTROL_REG, reg | 0x80);
uint8_t val = inp(CMOS_DATA_REG);
spin_unlock_irqrestore(&lock, state);
return val;
}