External/cloud-hypervisor
1
0
Fork 0
mirror of https://github.com/cloud-hypervisor/cloud-hypervisor.git synced 2024-07-04 17:02:36 +00:00
Code Issues Packages Projects Releases Wiki Activity

devices: cmos: Populate Update in Progress bit (UIP)

Browse Source 
This bit should be set for the last 224us of each second. To be able to
fill this bit we need to use clock_gettime() to get the nanoseconds.
Also set the frequency bit to indicate we update at 32kHz.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>
This commit is contained in:
Rob Bradford 2020-07-21 16:30:14 +01:00 committed by Sebastien Boeuf
parent f03afea0d6
commit 08288305ef
1 changed files with 17 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
devices/src/legacy/cmos.rs
View File

@ -2,7 +2,7 @@
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
use libc::{gmtime_r, time, time_t, tm};
use libc::{clock_gettime, gmtime_r, time_t, timespec, tm, CLOCK_REALTIME};
use std::cmp::min;
use std::mem;
@ -77,14 +77,17 @@ impl BusDevice for Cmos {
let day;
let month;
let year;
// The time and gmtime_r calls are safe as long as the structs they are given are
// large enough, and neither of them fail. It is safe to zero initialize the tm
// struct because it contains only plain data.
unsafe {
// The clock_gettime and gmtime_r calls are safe as long as the structs they are
// given are large enough, and neither of them fail. It is safe to zero initialize
// the tm and timespec struct because it contains only plain data.
let update_in_progress = unsafe {
let mut timespec: timespec = mem::zeroed();
clock_gettime(CLOCK_REALTIME, &mut timespec as *mut _);
let now: time_t = timespec.tv_sec;
let mut tm: tm = mem::zeroed();
let mut now: time_t = 0;
time(&mut now as *mut _);
gmtime_r(&now, &mut tm as *mut _);
// The following lines of code are safe but depend on tm being in scope.
seconds = tm.tm_sec;
minutes = tm.tm_min;
@ -93,6 +96,11 @@ impl BusDevice for Cmos {
day = tm.tm_mday;
month = tm.tm_mon + 1;
year = tm.tm_year;
// Update in Progress bit held for last 224us of each second
const NANOSECONDS_PER_SECOND: i64 = 1_000_000_000;
const UIP_HOLD_LENGTH: i64 = 8 * NANOSECONDS_PER_SECOND / 32768;
timespec.tv_nsec >= (NANOSECONDS_PER_SECOND - UIP_HOLD_LENGTH)
};
match self.index {
0x00 => to_bcd(seconds as u8),
@ -102,6 +110,8 @@ impl BusDevice for Cmos {
0x07 => to_bcd(day as u8),
0x08 => to_bcd(month as u8),
0x09 => to_bcd((year % 100) as u8),
// Bit 5 for 32kHz clock. Bit 7 for Update in Progress
0x0a => 1 << 5 | (update_in_progress as u8) << 7,
0x32 => to_bcd(((year + 1900) / 100) as u8),
_ => {
// self.index is always guaranteed to be in range via INDEX_MASK.