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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
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>
-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
-rw-r--r--drivers/rtc/Kconfig12
-rw-r--r--drivers/rtc/Makefile1
-rw-r--r--drivers/rtc/rtc-mrst.c582
8 files changed, 780 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);
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 2883428d5ac..4941cade319 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -463,6 +463,18 @@ config RTC_DRV_CMOS
This driver can also be built as a module. If so, the module
will be called rtc-cmos.
+config RTC_DRV_VRTC
+ tristate "Virtual RTC for Moorestown platforms"
+ depends on X86_MRST
+ default y if X86_MRST
+
+ help
+ Say "yes" here to get direct support for the real time clock
+ found on Moorestown platforms. The VRTC is a emulated RTC that
+ derives its clock source from a real RTC in the PMIC. The MC146818
+ style programming interface is mostly conserved, but any
+ updates are done via IPC calls to the system controller FW.
+
config RTC_DRV_DS1216
tristate "Dallas DS1216"
depends on SNI_RM
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 4c2832df469..2afdaf3ff98 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_RTC_DRV_CMOS) += rtc-cmos.o
obj-$(CONFIG_RTC_DRV_COH901331) += rtc-coh901331.o
obj-$(CONFIG_RTC_DRV_DAVINCI) += rtc-davinci.o
obj-$(CONFIG_RTC_DRV_DM355EVM) += rtc-dm355evm.o
+obj-$(CONFIG_RTC_DRV_VRTC) += rtc-mrst.o
obj-$(CONFIG_RTC_DRV_DS1216) += rtc-ds1216.o
obj-$(CONFIG_RTC_DRV_DS1286) += rtc-ds1286.o
obj-$(CONFIG_RTC_DRV_DS1302) += rtc-ds1302.o
diff --git a/drivers/rtc/rtc-mrst.c b/drivers/rtc/rtc-mrst.c
new file mode 100644
index 00000000000..bcd0cf63eb1
--- /dev/null
+++ b/drivers/rtc/rtc-mrst.c
@@ -0,0 +1,582 @@
+/*
+ * rtc-mrst.c: Driver for Moorestown virtual RTC
+ *
+ * (C) Copyright 2009 Intel Corporation
+ * Author: Jacob Pan (jacob.jun.pan@intel.com)
+ * Feng Tang (feng.tang@intel.com)
+ *
+ * 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 upon drivers/rtc/rtc-cmos.c
+ */
+
+/*
+ * Note:
+ * * vRTC only supports binary mode and 24H mode
+ * * vRTC only support PIE and AIE, no UIE, and its PIE only happens
+ * at 23:59:59pm everyday, no support for adjustable frequency
+ * * Alarm function is also limited to hr/min/sec.
+ */
+
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/sfi.h>
+
+#include <asm-generic/rtc.h>
+#include <asm/intel_scu_ipc.h>
+#include <asm/mrst.h>
+#include <asm/mrst-vrtc.h>
+
+struct mrst_rtc {
+ struct rtc_device *rtc;
+ struct device *dev;
+ int irq;
+ struct resource *iomem;
+
+ u8 enabled_wake;
+ u8 suspend_ctrl;
+};
+
+static const char driver_name[] = "rtc_mrst";
+
+#define RTC_IRQMASK (RTC_PF | RTC_AF)
+
+static inline int is_intr(u8 rtc_intr)
+{
+ if (!(rtc_intr & RTC_IRQF))
+ return 0;
+ return rtc_intr & RTC_IRQMASK;
+}
+
+/*
+ * rtc_time's year contains the increment over 1900, but vRTC's YEAR
+ * register can't be programmed to value larger than 0x64, so vRTC
+ * driver chose to use 1960 (1970 is UNIX time start point) as the base,
+ * and does the translation at read/write time.
+ *
+ * Why not just use 1970 as the offset? it's because using 1960 will
+ * make it consistent in leap year setting for both vrtc and low-level
+ * physical rtc devices.
+ */
+static int mrst_read_time(struct device *dev, struct rtc_time *time)
+{
+ unsigned long flags;
+
+ if (rtc_is_updating())
+ mdelay(20);
+
+ spin_lock_irqsave(&rtc_lock, flags);
+ time->tm_sec = vrtc_cmos_read(RTC_SECONDS);
+ time->tm_min = vrtc_cmos_read(RTC_MINUTES);
+ time->tm_hour = vrtc_cmos_read(RTC_HOURS);
+ time->tm_mday = vrtc_cmos_read(RTC_DAY_OF_MONTH);
+ time->tm_mon = vrtc_cmos_read(RTC_MONTH);
+ time->tm_year = vrtc_cmos_read(RTC_YEAR);
+ spin_unlock_irqrestore(&rtc_lock, flags);
+
+ /* Adjust for the 1960/1900 */
+ time->tm_year += 60;
+ time->tm_mon--;
+ return RTC_24H;
+}
+
+static int mrst_set_time(struct device *dev, struct rtc_time *time)
+{
+ int ret;
+ unsigned long flags;
+ unsigned char mon, day, hrs, min, sec;
+ unsigned int yrs;
+
+ yrs = time->tm_year;
+ mon = time->tm_mon + 1; /* tm_mon starts at zero */
+ day = time->tm_mday;
+ hrs = time->tm_hour;
+ min = time->tm_min;
+ sec = time->tm_sec;
+
+ if (yrs < 70 || yrs > 138)
+ return -EINVAL;
+ yrs -= 60;
+
+ spin_lock_irqsave(&rtc_lock, flags);
+
+ vrtc_cmos_write(yrs, RTC_YEAR);
+ vrtc_cmos_write(mon, RTC_MONTH);
+ vrtc_cmos_write(day, RTC_DAY_OF_MONTH);
+ vrtc_cmos_write(hrs, RTC_HOURS);
+ vrtc_cmos_write(min, RTC_MINUTES);
+ vrtc_cmos_write(sec, RTC_SECONDS);
+
+ spin_unlock_irqrestore(&rtc_lock, flags);
+
+ ret = intel_scu_ipc_simple_command(IPCMSG_VRTC, IPC_CMD_VRTC_SETTIME);
+ return ret;
+}
+
+static int mrst_read_alarm(struct device *dev, struct rtc_wkalrm *t)
+{
+ struct mrst_rtc *mrst = dev_get_drvdata(dev);
+ unsigned char rtc_control;
+
+ if (mrst->irq <= 0)
+ return -EIO;
+
+ /* Basic alarms only support hour, minute, and seconds fields.
+ * Some also support day and month, for alarms up to a year in
+ * the future.
+ */
+ t->time.tm_mday = -1;
+ t->time.tm_mon = -1;
+ t->time.tm_year = -1;
+
+ /* vRTC only supports binary mode */
+ spin_lock_irq(&rtc_lock);
+ t->time.tm_sec = vrtc_cmos_read(RTC_SECONDS_ALARM);
+ t->time.tm_min = vrtc_cmos_read(RTC_MINUTES_ALARM);
+ t->time.tm_hour = vrtc_cmos_read(RTC_HOURS_ALARM);
+
+ rtc_control = vrtc_cmos_read(RTC_CONTROL);
+ spin_unlock_irq(&rtc_lock);
+
+ t->enabled = !!(rtc_control & RTC_AIE);
+ t->pending = 0;
+
+ return 0;
+}
+
+static void mrst_checkintr(struct mrst_rtc *mrst, unsigned char rtc_control)
+{
+ unsigned char rtc_intr;
+
+ /*
+ * NOTE after changing RTC_xIE bits we always read INTR_FLAGS;
+ * allegedly some older rtcs need that to handle irqs properly
+ */
+ rtc_intr = vrtc_cmos_read(RTC_INTR_FLAGS);
+ rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
+ if (is_intr(rtc_intr))
+ rtc_update_irq(mrst->rtc, 1, rtc_intr);
+}
+
+static void mrst_irq_enable(struct mrst_rtc *mrst, unsigned char mask)
+{
+ unsigned char rtc_control;
+
+ /*
+ * Flush any pending IRQ status, notably for update irqs,
+ * before we enable new IRQs
+ */
+ rtc_control = vrtc_cmos_read(RTC_CONTROL);
+ mrst_checkintr(mrst, rtc_control);
+
+ rtc_control |= mask;
+ vrtc_cmos_write(rtc_control, RTC_CONTROL);
+
+ mrst_checkintr(mrst, rtc_control);
+}
+
+static void mrst_irq_disable(struct mrst_rtc *mrst, unsigned char mask)
+{
+ unsigned char rtc_control;
+
+ rtc_control = vrtc_cmos_read(RTC_CONTROL);
+ rtc_control &= ~mask;
+ vrtc_cmos_write(rtc_control, RTC_CONTROL);
+ mrst_checkintr(mrst, rtc_control);
+}
+
+static int mrst_set_alarm(struct device *dev, struct rtc_wkalrm *t)
+{
+ struct mrst_rtc *mrst = dev_get_drvdata(dev);
+ unsigned char hrs, min, sec;
+ int ret = 0;
+
+ if (!mrst->irq)
+ return -EIO;
+
+ hrs = t->time.tm_hour;
+ min = t->time.tm_min;
+ sec = t->time.tm_sec;
+
+ spin_lock_irq(&rtc_lock);
+ /* Next rtc irq must not be from previous alarm setting */
+ mrst_irq_disable(mrst, RTC_AIE);
+
+ /* Update alarm */
+ vrtc_cmos_write(hrs, RTC_HOURS_ALARM);
+ vrtc_cmos_write(min, RTC_MINUTES_ALARM);
+ vrtc_cmos_write(sec, RTC_SECONDS_ALARM);
+
+ spin_unlock_irq(&rtc_lock);
+
+ ret = intel_scu_ipc_simple_command(IPCMSG_VRTC, IPC_CMD_VRTC_SETALARM);
+ if (ret)
+ return ret;
+
+ spin_lock_irq(&rtc_lock);
+ if (t->enabled)
+ mrst_irq_enable(mrst, RTC_AIE);
+
+ spin_unlock_irq(&rtc_lock);
+
+ return 0;
+}
+
+static int mrst_irq_set_state(struct device *dev, int enabled)
+{
+ struct mrst_rtc *mrst = dev_get_drvdata(dev);
+ unsigned long flags;
+
+ if (!mrst->irq)
+ return -ENXIO;
+
+ spin_lock_irqsave(&rtc_lock, flags);
+
+ if (enabled)
+ mrst_irq_enable(mrst, RTC_PIE);
+ else
+ mrst_irq_disable(mrst, RTC_PIE);
+
+ spin_unlock_irqrestore(&rtc_lock, flags);
+ return 0;
+}
+
+#if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)
+
+/* Currently, the vRTC doesn't support UIE ON/OFF */
+static int
+mrst_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+{
+ struct mrst_rtc *mrst = dev_get_drvdata(dev);
+ unsigned long flags;
+
+ switch (cmd) {
+ case RTC_AIE_OFF:
+ case RTC_AIE_ON:
+ if (!mrst->irq)
+ return -EINVAL;
+ break;
+ default:
+ /* PIE ON/OFF is handled by mrst_irq_set_state() */
+ return -ENOIOCTLCMD;
+ }
+
+ spin_lock_irqsave(&rtc_lock, flags);
+ switch (cmd) {
+ case RTC_AIE_OFF: /* alarm off */
+ mrst_irq_disable(mrst, RTC_AIE);
+ break;
+ case RTC_AIE_ON: /* alarm on */
+ mrst_irq_enable(mrst, RTC_AIE);
+ break;
+ }
+ spin_unlock_irqrestore(&rtc_lock, flags);
+ return 0;
+}
+
+#else
+#define mrst_rtc_ioctl NULL
+#endif
+
+#if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
+
+static int mrst_procfs(struct device *dev, struct seq_file *seq)
+{
+ unsigned char rtc_control, valid;
+
+ spin_lock_irq(&rtc_lock);
+ rtc_control = vrtc_cmos_read(RTC_CONTROL);
+ valid = vrtc_cmos_read(RTC_VALID);
+ spin_unlock_irq(&rtc_lock);
+
+ return seq_printf(seq,
+ "periodic_IRQ\t: %s\n"
+ "alarm\t\t: %s\n"
+ "BCD\t\t: no\n"
+ "periodic_freq\t: daily (not adjustable)\n",
+ (rtc_control & RTC_PIE) ? "on" : "off",
+ (rtc_control & RTC_AIE) ? "on" : "off");
+}
+
+#else
+#define mrst_procfs NULL
+#endif
+
+static const struct rtc_class_ops mrst_rtc_ops = {
+ .ioctl = mrst_rtc_ioctl,
+ .read_time = mrst_read_time,
+ .set_time = mrst_set_time,
+ .read_alarm = mrst_read_alarm,
+ .set_alarm = mrst_set_alarm,
+ .proc = mrst_procfs,
+ .irq_set_state = mrst_irq_set_state,
+};
+
+static struct mrst_rtc mrst_rtc;
+
+/*
+ * When vRTC IRQ is captured by SCU FW, FW will clear the AIE bit in
+ * Reg B, so no need for this driver to clear it
+ */
+static irqreturn_t mrst_rtc_irq(int irq, void *p)
+{
+ u8 irqstat;
+
+ spin_lock(&rtc_lock);
+ /* This read will clear all IRQ flags inside Reg C */
+ irqstat = vrtc_cmos_read(RTC_INTR_FLAGS);
+ spin_unlock(&rtc_lock);
+
+ irqstat &= RTC_IRQMASK | RTC_IRQF;
+ if (is_intr(irqstat)) {
+ rtc_update_irq(p, 1, irqstat);
+ return IRQ_HANDLED;
+ }
+ return IRQ_NONE;
+}
+
+static int __init
+vrtc_mrst_do_probe(struct device *dev, struct resource *iomem, int rtc_irq)
+{
+ int retval = 0;
+ unsigned char rtc_control;
+
+ /* There can be only one ... */
+ if (mrst_rtc.dev)
+ return -EBUSY;
+
+ if (!iomem)
+ return -ENODEV;
+
+ iomem = request_mem_region(iomem->start,
+ iomem->end + 1 - iomem->start,
+ driver_name);
+ if (!iomem) {
+ dev_dbg(dev, "i/o mem already in use.\n");
+ return -EBUSY;
+ }
+
+ mrst_rtc.irq = rtc_irq;
+ mrst_rtc.iomem = iomem;
+
+ mrst_rtc.rtc = rtc_device_register(driver_name, dev,
+ &mrst_rtc_ops, THIS_MODULE);
+ if (IS_ERR(mrst_rtc.rtc)) {
+ retval = PTR_ERR(mrst_rtc.rtc);
+ goto cleanup0;
+ }
+
+ mrst_rtc.dev = dev;
+ dev_set_drvdata(dev, &mrst_rtc);
+ rename_region(iomem, dev_name(&mrst_rtc.rtc->dev));
+
+ spin_lock_irq(&rtc_lock);
+ mrst_irq_disable(&mrst_rtc, RTC_PIE | RTC_AIE);
+ rtc_control = vrtc_cmos_read(RTC_CONTROL);
+ spin_unlock_irq(&rtc_lock);
+
+ if (!(rtc_control & RTC_24H) || (rtc_control & (RTC_DM_BINARY)))
+ dev_dbg(dev, "TODO: support more than 24-hr BCD mode\n");
+
+ if (rtc_irq) {
+ retval = request_irq(rtc_irq, mrst_rtc_irq,
+ IRQF_DISABLED, dev_name(&mrst_rtc.rtc->dev),
+ mrst_rtc.rtc);
+ if (retval < 0) {
+ dev_dbg(dev, "IRQ %d is already in use, err %d\n",
+ rtc_irq, retval);
+ goto cleanup1;
+ }
+ }
+ dev_dbg(dev, "initialised\n");
+ return 0;
+
+cleanup1:
+ mrst_rtc.dev = NULL;
+ rtc_device_unregister(mrst_rtc.rtc);
+cleanup0:
+ release_region(iomem->start, iomem->end + 1 - iomem->start);
+ dev_err(dev, "rtc-mrst: unable to initialise\n");
+ return retval;
+}
+
+static void rtc_mrst_do_shutdown(void)
+{
+ spin_lock_irq(&rtc_lock);
+ mrst_irq_disable(&mrst_rtc, RTC_IRQMASK);
+ spin_unlock_irq(&rtc_lock);
+}
+
+static void __exit rtc_mrst_do_remove(struct device *dev)
+{
+ struct mrst_rtc *mrst = dev_get_drvdata(dev);
+ struct resource *iomem;
+
+ rtc_mrst_do_shutdown();
+
+ if (mrst->irq)
+ free_irq(mrst->irq, mrst->rtc);
+
+ rtc_device_unregister(mrst->rtc);
+ mrst->rtc = NULL;
+
+ iomem = mrst->iomem;
+ release_region(iomem->start, iomem->end + 1 - iomem->start);
+ mrst->iomem = NULL;
+
+ mrst->dev = NULL;
+ dev_set_drvdata(dev, NULL);
+}
+
+#ifdef CONFIG_PM
+static int mrst_suspend(struct device *dev, pm_message_t mesg)
+{
+ struct mrst_rtc *mrst = dev_get_drvdata(dev);
+ unsigned char tmp;
+
+ /* Only the alarm might be a wakeup event source */
+ spin_lock_irq(&rtc_lock);
+ mrst->suspend_ctrl = tmp = vrtc_cmos_read(RTC_CONTROL);
+ if (tmp & (RTC_PIE | RTC_AIE)) {
+ unsigned char mask;
+
+ if (device_may_wakeup(dev))
+ mask = RTC_IRQMASK & ~RTC_AIE;
+ else
+ mask = RTC_IRQMASK;
+ tmp &= ~mask;
+ vrtc_cmos_write(tmp, RTC_CONTROL);
+
+ mrst_checkintr(mrst, tmp);
+ }
+ spin_unlock_irq(&rtc_lock);
+
+ if (tmp & RTC_AIE) {
+ mrst->enabled_wake = 1;
+ enable_irq_wake(mrst->irq);
+ }
+
+ dev_dbg(&mrst_rtc.rtc->dev, "suspend%s, ctrl %02x\n",
+ (tmp & RTC_AIE) ? ", alarm may wake" : "",
+ tmp);
+
+ return 0;
+}
+
+/*
+ * We want RTC alarms to wake us from the deep power saving state
+ */
+static inline int mrst_poweroff(struct device *dev)
+{
+ return mrst_suspend(dev, PMSG_HIBERNATE);
+}
+
+static int mrst_resume(struct device *dev)
+{
+ struct mrst_rtc *mrst = dev_get_drvdata(dev);
+ unsigned char tmp = mrst->suspend_ctrl;
+
+ /* Re-enable any irqs previously active */
+ if (tmp & RTC_IRQMASK) {
+ unsigned char mask;
+
+ if (mrst->enabled_wake) {
+ disable_irq_wake(mrst->irq);
+ mrst->enabled_wake = 0;
+ }
+
+ spin_lock_irq(&rtc_lock);
+ do {
+ vrtc_cmos_write(tmp, RTC_CONTROL);
+
+ mask = vrtc_cmos_read(RTC_INTR_FLAGS);
+ mask &= (tmp & RTC_IRQMASK) | RTC_IRQF;
+ if (!is_intr(mask))
+ break;
+
+ rtc_update_irq(mrst->rtc, 1, mask);
+ tmp &= ~RTC_AIE;
+ } while (mask & RTC_AIE);
+ spin_unlock_irq(&rtc_lock);
+ }
+
+ dev_dbg(&mrst_rtc.rtc->dev, "resume, ctrl %02x\n", tmp);
+
+ return 0;
+}
+
+#else
+#define mrst_suspend NULL
+#define mrst_resume NULL
+
+static inline int mrst_poweroff(struct device *dev)
+{
+ return -ENOSYS;
+}
+
+#endif
+
+static int __init vrtc_mrst_platform_probe(struct platform_device *pdev)
+{
+ return vrtc_mrst_do_probe(&pdev->dev,
+ platform_get_resource(pdev, IORESOURCE_MEM, 0),
+ platform_get_irq(pdev, 0));
+}
+
+static int __exit vrtc_mrst_platform_remove(struct platform_device *pdev)
+{
+ rtc_mrst_do_remove(&pdev->dev);
+ return 0;
+}
+
+static void vrtc_mrst_platform_shutdown(struct platform_device *pdev)
+{
+ if (system_state == SYSTEM_POWER_OFF && !mrst_poweroff(&pdev->dev))
+ return;
+
+ rtc_mrst_do_shutdown();
+}
+
+MODULE_ALIAS("platform:vrtc_mrst");
+
+static struct platform_driver vrtc_mrst_platform_driver = {
+ .probe = vrtc_mrst_platform_probe,
+ .remove = __exit_p(vrtc_mrst_platform_remove),
+ .shutdown = vrtc_mrst_platform_shutdown,
+ .driver = {
+ .name = (char *) driver_name,
+ .suspend = mrst_suspend,
+ .resume = mrst_resume,
+ }
+};
+
+static int __init vrtc_mrst_init(void)
+{
+ return platform_driver_register(&vrtc_mrst_platform_driver);
+}
+
+static void __exit vrtc_mrst_exit(void)
+{
+ platform_driver_unregister(&vrtc_mrst_platform_driver);
+}
+
+module_init(vrtc_mrst_init);
+module_exit(vrtc_mrst_exit);
+
+MODULE_AUTHOR("Jacob Pan; Feng Tang");
+MODULE_DESCRIPTION("Driver for Moorestown virtual RTC");
+MODULE_LICENSE("GPL");