diff options
author | Feng Tang <feng.tang@intel.com> | 2010-11-10 17:29:00 (GMT) |
---|---|---|
committer | Thomas Gleixner <tglx@linutronix.de> | 2010-11-11 10:34:27 (GMT) |
commit | 7309282c90d251cde77fe3b520a8276e25315c49 (patch) | |
tree | da33c8a838d0ee779c1b8a70e13002bf29cd4527 /arch/x86/platform | |
parent | cfb505a7ebd4c84206b4cc7d9f966d864a2ac05a (diff) | |
download | linux-7309282c90d251cde77fe3b520a8276e25315c49.tar.xz |
x86: mrst: Add vrtc driver which serves as a wall clock device
Moorestown platform doesn't have a m146818 RTC device like traditional
x86 PC, but a firmware emulated virtual RTC device(vrtc), which provides
some basic RTC functions like get/set time. vrtc serves as the only
wall clock device on Moorestown platform.
[ tglx: Changed the exports to _GPL ]
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
LKML-Reference: <20101110172837.3311.40483.stgit@localhost.localdomain>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/platform')
-rw-r--r-- | arch/x86/platform/mrst/Makefile | 1 | ||||
-rw-r--r-- | arch/x86/platform/mrst/mrst.c | 6 | ||||
-rw-r--r-- | arch/x86/platform/mrst/vrtc.c | 120 |
3 files changed, 121 insertions, 6 deletions
diff --git a/arch/x86/platform/mrst/Makefile b/arch/x86/platform/mrst/Makefile index efbbc55..4d3e256 100644 --- a/arch/x86/platform/mrst/Makefile +++ b/arch/x86/platform/mrst/Makefile @@ -1 +1,2 @@ obj-$(CONFIG_X86_MRST) += mrst.o +obj-$(CONFIG_X86_MRST) += vrtc.o diff --git a/arch/x86/platform/mrst/mrst.c b/arch/x86/platform/mrst/mrst.c index c727d97..42a0351f 100644 --- a/arch/x86/platform/mrst/mrst.c +++ b/arch/x86/platform/mrst/mrst.c @@ -37,7 +37,6 @@ #include <asm/apb_timer.h> #include <asm/reboot.h> - /* * the clockevent devices on Moorestown/Medfield can be APBT or LAPIC clock, * cmdline option x86_mrst_timer can be used to override the configuration @@ -242,11 +241,6 @@ void __init mrst_time_init(void) apbt_time_init(); } -void __init mrst_rtc_init(void) -{ - sfi_table_parse(SFI_SIG_MRTC, NULL, NULL, sfi_parse_mrtc); -} - void __cpuinit mrst_arch_setup(void) { if (boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model == 0x27) diff --git a/arch/x86/platform/mrst/vrtc.c b/arch/x86/platform/mrst/vrtc.c new file mode 100644 index 0000000..4944bd5 --- /dev/null +++ b/arch/x86/platform/mrst/vrtc.c @@ -0,0 +1,120 @@ +/* + * 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; +} |