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authorFeng Tang <feng.tang@intel.com>2010-12-09 10:37:36 +0000
committerAlan Cox <alan@linux.intel.com>2010-12-09 10:37:36 +0000
commit30c35436894b81172616e72f1a1a6ca5229ee2d9 (patch)
tree51a825f7e7d061833c8175556a2417d2d2172b69 /arch
parent9cb27e7e4655d1beefc091575def62299c5adff1 (diff)
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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')
-rw-r--r--arch/x86/include/asm/mrst-vrtc.h9
-rw-r--r--arch/x86/include/asm/mrst.h10
-rw-r--r--arch/x86/platform/mrst/Makefile1
-rw-r--r--arch/x86/platform/mrst/mrst.c6
-rw-r--r--arch/x86/platform/mrst/vrtc.c166
5 files changed, 185 insertions, 7 deletions
diff --git a/arch/x86/include/asm/mrst-vrtc.h b/arch/x86/include/asm/mrst-vrtc.h
new file mode 100644
index 00000000000..73668abdbed
--- /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 283debd29fc..719f00b28ff 100644
--- a/arch/x86/include/asm/mrst.h
+++ b/arch/x86/include/asm/mrst.h
@@ -14,7 +14,9 @@
#include <linux/sfi.h>
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 efbbc552fa9..4d3e256780b 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 d9d5eaba91f..0aa9f51a544 100644
--- a/arch/x86/platform/mrst/mrst.c
+++ b/arch/x86/platform/mrst/mrst.c
@@ -36,7 +36,6 @@
#include <asm/intel_scu_ipc.h>
#include <asm/apb_timer.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
@@ -243,11 +242,6 @@ 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 00000000000..4d3f770456f
--- /dev/null
+++ b/arch/x86/platform/mrst/vrtc.c
@@ -0,0 +1,166 @@
+/*
+ * 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 <linux/platform_device.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;
+}
+
+/*
+ * The Moorestown platform has a memory mapped virtual RTC device that emulates
+ * the programming interface of the RTC.
+ */
+
+static struct resource vrtc_resources[] = {
+ [0] = {
+ .flags = IORESOURCE_MEM,
+ },
+ [1] = {
+ .flags = IORESOURCE_IRQ,
+ }
+};
+
+static struct platform_device vrtc_device = {
+ .name = "rtc_mrst",
+ .id = -1,
+ .resource = vrtc_resources,
+ .num_resources = ARRAY_SIZE(vrtc_resources),
+};
+
+/* Register the RTC device if appropriate */
+static int __init mrst_device_create(void)
+{
+ /* No Moorestown, no device */
+ if (!mrst_identify_cpu())
+ return -ENODEV;
+ /* No timer, no device */
+ if (!sfi_mrtc_num)
+ return -ENODEV;
+
+ /* iomem resource */
+ vrtc_resources[0].start = sfi_mrtc_array[0].phys_addr;
+ vrtc_resources[0].end = sfi_mrtc_array[0].phys_addr +
+ MRST_VRTC_MAP_SZ;
+ /* irq resource */
+ vrtc_resources[1].start = sfi_mrtc_array[0].irq;
+ vrtc_resources[1].end = sfi_mrtc_array[0].irq;
+
+ platform_device_register(&vrtc_device);
+ return 0;
+}
+
+module_init(mrst_device_create);