From: Feng Tang Date: Wed, 10 Nov 2010 17:29:00 +0000 (+0000) Subject: x86: mrst: Add vrtc driver which serves as a wall clock device X-Git-Tag: upstream/snapshot3+hdmi~10404^2~45 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=7309282c90d251cde77fe3b520a8276e25315c49;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git 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 Signed-off-by: Jacob Pan Signed-off-by: Alan Cox LKML-Reference: <20101110172837.3311.40483.stgit@localhost.localdomain> Signed-off-by: Thomas Gleixner --- diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h index 4d293dc..139591a 100644 --- a/arch/x86/include/asm/fixmap.h +++ b/arch/x86/include/asm/fixmap.h @@ -117,6 +117,10 @@ enum fixed_addresses { FIX_TEXT_POKE1, /* reserve 2 pages for text_poke() */ FIX_TEXT_POKE0, /* first page is last, because allocation is backward */ __end_of_permanent_fixed_addresses, + +#ifdef CONFIG_X86_MRST + FIX_LNW_VRTC, +#endif /* * 256 temporary boot-time mappings, used by early_ioremap(), * before ioremap() is functional. diff --git a/arch/x86/include/asm/mrst-vrtc.h b/arch/x86/include/asm/mrst-vrtc.h new file mode 100644 index 0000000..73668ab --- /dev/null +++ b/arch/x86/include/asm/mrst-vrtc.h @@ -0,0 +1,9 @@ +#ifndef _MRST_VRTC_H +#define _MRST_VRTC_H + +extern unsigned char vrtc_cmos_read(unsigned char reg); +extern void vrtc_cmos_write(unsigned char val, unsigned char reg); +extern unsigned long vrtc_get_time(void); +extern int vrtc_set_mmss(unsigned long nowtime); + +#endif diff --git a/arch/x86/include/asm/mrst.h b/arch/x86/include/asm/mrst.h index 283debd..719f00b 100644 --- a/arch/x86/include/asm/mrst.h +++ b/arch/x86/include/asm/mrst.h @@ -14,7 +14,9 @@ #include extern int pci_mrst_init(void); -int __init sfi_parse_mrtc(struct sfi_table_header *table); +extern int __init sfi_parse_mrtc(struct sfi_table_header *table); +extern int sfi_mrtc_num; +extern struct sfi_rtc_table_entry sfi_mrtc_array[]; /* * Medfield is the follow-up of Moorestown, it combines two chip solution into @@ -54,4 +56,10 @@ extern void hsu_early_console_init(void); extern void intel_scu_devices_create(void); extern void intel_scu_devices_destroy(void); +/* VRTC timer */ +#define MRST_VRTC_MAP_SZ (1024) +/*#define MRST_VRTC_PGOFFSET (0xc00) */ + +extern void mrst_rtc_init(void); + #endif /* _ASM_X86_MRST_H */ 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..42a0351 100644 --- a/arch/x86/platform/mrst/mrst.c +++ b/arch/x86/platform/mrst/mrst.c @@ -37,7 +37,6 @@ #include #include - /* * 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 +#include +#include + +#include +#include +#include +#include + +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; +}