+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * 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)
- *
- * 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/mc146818rtc.h>
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/sfi.h>
-
-#include <asm/intel_scu_ipc.h>
-#include <asm/intel-mid.h>
-#include <asm/intel_mid_vrtc.h>
-
-struct mrst_rtc {
- struct rtc_device *rtc;
- struct device *dev;
- int irq;
-
- 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;
-}
-
-static inline unsigned char vrtc_is_updating(void)
-{
- unsigned char uip;
- unsigned long flags;
-
- spin_lock_irqsave(&rtc_lock, flags);
- uip = (vrtc_cmos_read(RTC_FREQ_SELECT) & RTC_UIP);
- spin_unlock_irqrestore(&rtc_lock, flags);
- return uip;
-}
-
-/*
- * 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 1972 (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 1972 will
- * make it consistent in leap year setting for both vrtc and low-level
- * physical rtc devices. Then why not use 1960 as the offset? If we use
- * 1960, for a device's first use, its YEAR register is 0 and the system
- * year will be parsed as 1960 which is not a valid UNIX time and will
- * cause many applications to fail mysteriously.
- */
-static int mrst_read_time(struct device *dev, struct rtc_time *time)
-{
- unsigned long flags;
-
- if (vrtc_is_updating())
- msleep(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 1972/1900 */
- time->tm_year += 72;
- time->tm_mon--;
- return 0;
-}
-
-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 < 72 || yrs > 172)
- return -EINVAL;
- yrs -= 72;
-
- 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;
-
- /* 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;
-}
-
-/* Currently, the vRTC doesn't support UIE ON/OFF */
-static int mrst_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
-{
- struct mrst_rtc *mrst = dev_get_drvdata(dev);
- unsigned long flags;
-
- spin_lock_irqsave(&rtc_lock, flags);
- if (enabled)
- mrst_irq_enable(mrst, RTC_AIE);
- else
- mrst_irq_disable(mrst, RTC_AIE);
- spin_unlock_irqrestore(&rtc_lock, flags);
- return 0;
-}
-
-
-#if IS_ENABLED(CONFIG_RTC_INTF_PROC)
-
-static int mrst_procfs(struct device *dev, struct seq_file *seq)
-{
- unsigned char rtc_control;
-
- spin_lock_irq(&rtc_lock);
- rtc_control = vrtc_cmos_read(RTC_CONTROL);
- spin_unlock_irq(&rtc_lock);
-
- 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");
-
- return 0;
-}
-
-#else
-#define mrst_procfs NULL
-#endif
-
-static const struct rtc_class_ops mrst_rtc_ops = {
- .read_time = mrst_read_time,
- .set_time = mrst_set_time,
- .read_alarm = mrst_read_alarm,
- .set_alarm = mrst_set_alarm,
- .proc = mrst_procfs,
- .alarm_irq_enable = mrst_rtc_alarm_irq_enable,
-};
-
-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 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 = devm_request_mem_region(dev, iomem->start, resource_size(iomem),
- driver_name);
- if (!iomem) {
- dev_dbg(dev, "i/o mem already in use.\n");
- return -EBUSY;
- }
-
- mrst_rtc.irq = rtc_irq;
- mrst_rtc.dev = dev;
- dev_set_drvdata(dev, &mrst_rtc);
-
- mrst_rtc.rtc = devm_rtc_allocate_device(dev);
- if (IS_ERR(mrst_rtc.rtc))
- return PTR_ERR(mrst_rtc.rtc);
-
- mrst_rtc.rtc->ops = &mrst_rtc_ops;
-
- 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 = devm_request_irq(dev, rtc_irq, mrst_rtc_irq,
- 0, 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 cleanup0;
- }
- }
-
- retval = devm_rtc_register_device(mrst_rtc.rtc);
- if (retval)
- goto cleanup0;
-
- dev_dbg(dev, "initialised\n");
- return 0;
-
-cleanup0:
- mrst_rtc.dev = NULL;
- 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 rtc_mrst_do_remove(struct device *dev)
-{
- struct mrst_rtc *mrst = dev_get_drvdata(dev);
-
- rtc_mrst_do_shutdown();
-
- mrst->rtc = NULL;
- mrst->dev = NULL;
-}
-
-#ifdef CONFIG_PM_SLEEP
-static int mrst_suspend(struct device *dev)
-{
- 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);
-}
-
-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;
-}
-
-static SIMPLE_DEV_PM_OPS(mrst_pm_ops, mrst_suspend, mrst_resume);
-#define MRST_PM_OPS (&mrst_pm_ops)
-
-#else
-#define MRST_PM_OPS NULL
-
-static inline int mrst_poweroff(struct device *dev)
-{
- return -ENOSYS;
-}
-
-#endif
-
-static int 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 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 = vrtc_mrst_platform_remove,
- .shutdown = vrtc_mrst_platform_shutdown,
- .driver = {
- .name = driver_name,
- .pm = MRST_PM_OPS,
- }
-};
-
-module_platform_driver(vrtc_mrst_platform_driver);
-
-MODULE_AUTHOR("Jacob Pan; Feng Tang");
-MODULE_DESCRIPTION("Driver for Moorestown virtual RTC");
-MODULE_LICENSE("GPL");
projects / linux-2.6-microblaze.git / commitdiff