rtc: Add drivers/rtc/rtc-mrst.c (0146f261) · Commits · 戴 / test

arch/x86/platform/mrst/vrtc.c

+46 −0

Original line number	Diff line number	Diff line
		@@ -20,6 +20,7 @@
		#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>
		@@ -118,3 +119,48 @@ void __init mrst_rtc_init(void)
		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);

drivers/rtc/Kconfig

+12 −0

Original line number	Diff line number	Diff line
		@@ -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

drivers/rtc/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -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

drivers/rtc/rtc-mrst.c

0 → 100644

+578 −0

Original line number	Diff line number	Diff line
		/*
		* 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
		*/
		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");

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