121 lines
2.8 KiB
C
121 lines
2.8 KiB
C
|
/*
|
||
|
|
* vrtc.c: Driver for virtual RTC device on Intel MID platform
|
||
|
|
*
|
||
|
|
* (C) Copyright 2009 Intel Corporation
|
||
|
|
*
|
||
|
|
* This program is free software; you can redistribute it and/or
|
||
|
|
* modify it under the terms of the GNU General Public License
|
||
|
|
* as published by the Free Software Foundation; version 2
|
||
|
|
* of the License.
|
||
|
|
*
|
||
|
|
* Note:
|
||
|
|
* VRTC is emulated by system controller firmware, the real HW
|
||
|
|
* RTC is located in the PMIC device. SCU FW shadows PMIC RTC
|
||
|
|
* in a memory mapped IO space that is visible to the host IA
|
||
|
|
* processor.
|
||
|
|
*
|
||
|
|
* This driver is based on RTC CMOS driver.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/kernel.h>
|
||
|
|
#include <linux/init.h>
|
||
|
|
#include <linux/sfi.h>
|
||
|
|
|
||
|
|
#include <asm/mrst.h>
|
||
|
|
#include <asm/mrst-vrtc.h>
|
||
|
|
#include <asm/time.h>
|
||
|
|
#include <asm/fixmap.h>
|
||
|
|
|
||
|
|
static unsigned char __iomem *vrtc_virt_base;
|
||
|
|
|
||
|
|
unsigned char vrtc_cmos_read(unsigned char reg)
|
||
|
|
{
|
||
|
|
unsigned char retval;
|
||
|
|
|
||
|
|
/* vRTC's registers range from 0x0 to 0xD */
|
||
|
|
if (reg > 0xd || !vrtc_virt_base)
|
||
|
|
return 0xff;
|
||
|
|
|
||
|
|
lock_cmos_prefix(reg);
|
||
|
|
retval = __raw_readb(vrtc_virt_base + (reg << 2));
|
||
|
|
lock_cmos_suffix(reg);
|
||
|
|
return retval;
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(vrtc_cmos_read);
|
||
|
|
|
||
|
|
void vrtc_cmos_write(unsigned char val, unsigned char reg)
|
||
|
|
{
|
||
|
|
if (reg > 0xd || !vrtc_virt_base)
|
||
|
|
return;
|
||
|
|
|
||
|
|
lock_cmos_prefix(reg);
|
||
|
|
__raw_writeb(val, vrtc_virt_base + (reg << 2));
|
||
|
|
lock_cmos_suffix(reg);
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(vrtc_cmos_write);
|
||
|
|
|
||
|
|
unsigned long vrtc_get_time(void)
|
||
|
|
{
|
||
|
|
u8 sec, min, hour, mday, mon;
|
||
|
|
u32 year;
|
||
|
|
|
||
|
|
while ((vrtc_cmos_read(RTC_FREQ_SELECT) & RTC_UIP))
|
||
|
|
cpu_relax();
|
||
|
|
|
||
|
|
sec = vrtc_cmos_read(RTC_SECONDS);
|
||
|
|
min = vrtc_cmos_read(RTC_MINUTES);
|
||
|
|
hour = vrtc_cmos_read(RTC_HOURS);
|
||
|
|
mday = vrtc_cmos_read(RTC_DAY_OF_MONTH);
|
||
|
|
mon = vrtc_cmos_read(RTC_MONTH);
|
||
|
|
year = vrtc_cmos_read(RTC_YEAR);
|
||
|
|
|
||
|
|
/* vRTC YEAR reg contains the offset to 1960 */
|
||
|
|
year += 1960;
|
||
|
|
|
||
|
|
printk(KERN_INFO "vRTC: sec: %d min: %d hour: %d day: %d "
|
||
|
|
"mon: %d year: %d\n", sec, min, hour, mday, mon, year);
|
||
|
|
|
||
|
|
return mktime(year, mon, mday, hour, min, sec);
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Only care about the minutes and seconds */
|
||
|
|
int vrtc_set_mmss(unsigned long nowtime)
|
||
|
|
{
|
||
|
|
int real_sec, real_min;
|
||
|
|
int vrtc_min;
|
||
|
|
|
||
|
|
vrtc_min = vrtc_cmos_read(RTC_MINUTES);
|
||
|
|
|
||
|
|
real_sec = nowtime % 60;
|
||
|
|
real_min = nowtime / 60;
|
||
|
|
if (((abs(real_min - vrtc_min) + 15)/30) & 1)
|
||
|
|
real_min += 30;
|
||
|
|
real_min %= 60;
|
||
|
|
|
||
|
|
vrtc_cmos_write(real_sec, RTC_SECONDS);
|
||
|
|
vrtc_cmos_write(real_min, RTC_MINUTES);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
void __init mrst_rtc_init(void)
|
||
|
|
{
|
||
|
|
unsigned long rtc_paddr;
|
||
|
|
void __iomem *virt_base;
|
||
|
|
|
||
|
|
sfi_table_parse(SFI_SIG_MRTC, NULL, NULL, sfi_parse_mrtc);
|
||
|
|
if (!sfi_mrtc_num)
|
||
|
|
return;
|
||
|
|
|
||
|
|
rtc_paddr = sfi_mrtc_array[0].phys_addr;
|
||
|
|
|
||
|
|
/* vRTC's register address may not be page aligned */
|
||
|
|
set_fixmap_nocache(FIX_LNW_VRTC, rtc_paddr);
|
||
|
|
|
||
|
|
virt_base = (void __iomem *)__fix_to_virt(FIX_LNW_VRTC);
|
||
|
|
virt_base += rtc_paddr & ~PAGE_MASK;
|
||
|
|
vrtc_virt_base = virt_base;
|
||
|
|
|
||
|
|
x86_platform.get_wallclock = vrtc_get_time;
|
||
|
|
x86_platform.set_wallclock = vrtc_set_mmss;
|
||
|
|
}
|