unicore32 core architecture: timer and time handling
GuanXuetao [Sat, 15 Jan 2011 10:19:03 +0000 (18:19 +0800)]
This patch implements timer and time.
RTC and PWM device drivers are also here.

Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>

arch/unicore32/include/asm/timex.h [new file with mode: 0644]
arch/unicore32/kernel/pwm.c [new file with mode: 0644]
arch/unicore32/kernel/rtc.c [new file with mode: 0644]
arch/unicore32/kernel/time.c [new file with mode: 0644]

diff --git a/arch/unicore32/include/asm/timex.h b/arch/unicore32/include/asm/timex.h
new file mode 100644 (file)
index 0000000..faf16ba
--- /dev/null
@@ -0,0 +1,34 @@
+/*
+ * linux/arch/unicore32/include/asm/timex.h
+ *
+ * Code specific to PKUnity SoC and UniCore ISA
+ *
+ * Copyright (C) 2001-2010 GUAN Xue-tao
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __UNICORE_TIMEX_H__
+#define __UNICORE_TIMEX_H__
+
+#ifdef CONFIG_ARCH_FPGA
+
+/* in FPGA, APB clock is 33M, and OST clock is 32K, */
+/* so, 1M is selected for timer interrupt correctly */
+#define        CLOCK_TICK_RATE         (32*1024)
+
+#endif
+
+#if defined(CONFIG_PUV3_DB0913)                \
+       || defined(CONFIG_PUV3_NB0916)  \
+       || defined(CONFIG_PUV3_SMW0919)
+
+#define  CLOCK_TICK_RATE         (14318000)
+
+#endif
+
+#include <asm-generic/timex.h>
+
+#endif
diff --git a/arch/unicore32/kernel/pwm.c b/arch/unicore32/kernel/pwm.c
new file mode 100644 (file)
index 0000000..4615d51
--- /dev/null
@@ -0,0 +1,263 @@
+/*
+ * linux/arch/unicore32/kernel/pwm.c
+ *
+ * Code specific to PKUnity SoC and UniCore ISA
+ *
+ *     Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn>
+ *     Copyright (C) 2001-2010 Guan Xuetao
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/pwm.h>
+
+#include <asm/div64.h>
+#include <mach/hardware.h>
+
+struct pwm_device {
+       struct list_head        node;
+       struct platform_device *pdev;
+
+       const char      *label;
+       struct clk      *clk;
+       int             clk_enabled;
+
+       unsigned int    use_count;
+       unsigned int    pwm_id;
+};
+
+/*
+ * period_ns = 10^9 * (PRESCALE + 1) * (PV + 1) / PWM_CLK_RATE
+ * duty_ns   = 10^9 * (PRESCALE + 1) * DC / PWM_CLK_RATE
+ */
+int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
+{
+       unsigned long long c;
+       unsigned long period_cycles, prescale, pv, dc;
+
+       if (pwm == NULL || period_ns == 0 || duty_ns > period_ns)
+               return -EINVAL;
+
+       c = clk_get_rate(pwm->clk);
+       c = c * period_ns;
+       do_div(c, 1000000000);
+       period_cycles = c;
+
+       if (period_cycles < 1)
+               period_cycles = 1;
+       prescale = (period_cycles - 1) / 1024;
+       pv = period_cycles / (prescale + 1) - 1;
+
+       if (prescale > 63)
+               return -EINVAL;
+
+       if (duty_ns == period_ns)
+               dc = OST_PWMDCCR_FDCYCLE;
+       else
+               dc = (pv + 1) * duty_ns / period_ns;
+
+       /* NOTE: the clock to PWM has to be enabled first
+        * before writing to the registers
+        */
+       clk_enable(pwm->clk);
+       OST_PWMPWCR = prescale;
+       OST_PWMDCCR = pv - dc;
+       OST_PWMPCR  = pv;
+       clk_disable(pwm->clk);
+
+       return 0;
+}
+EXPORT_SYMBOL(pwm_config);
+
+int pwm_enable(struct pwm_device *pwm)
+{
+       int rc = 0;
+
+       if (!pwm->clk_enabled) {
+               rc = clk_enable(pwm->clk);
+               if (!rc)
+                       pwm->clk_enabled = 1;
+       }
+       return rc;
+}
+EXPORT_SYMBOL(pwm_enable);
+
+void pwm_disable(struct pwm_device *pwm)
+{
+       if (pwm->clk_enabled) {
+               clk_disable(pwm->clk);
+               pwm->clk_enabled = 0;
+       }
+}
+EXPORT_SYMBOL(pwm_disable);
+
+static DEFINE_MUTEX(pwm_lock);
+static LIST_HEAD(pwm_list);
+
+struct pwm_device *pwm_request(int pwm_id, const char *label)
+{
+       struct pwm_device *pwm;
+       int found = 0;
+
+       mutex_lock(&pwm_lock);
+
+       list_for_each_entry(pwm, &pwm_list, node) {
+               if (pwm->pwm_id == pwm_id) {
+                       found = 1;
+                       break;
+               }
+       }
+
+       if (found) {
+               if (pwm->use_count == 0) {
+                       pwm->use_count++;
+                       pwm->label = label;
+               } else
+                       pwm = ERR_PTR(-EBUSY);
+       } else
+               pwm = ERR_PTR(-ENOENT);
+
+       mutex_unlock(&pwm_lock);
+       return pwm;
+}
+EXPORT_SYMBOL(pwm_request);
+
+void pwm_free(struct pwm_device *pwm)
+{
+       mutex_lock(&pwm_lock);
+
+       if (pwm->use_count) {
+               pwm->use_count--;
+               pwm->label = NULL;
+       } else
+               pr_warning("PWM device already freed\n");
+
+       mutex_unlock(&pwm_lock);
+}
+EXPORT_SYMBOL(pwm_free);
+
+static inline void __add_pwm(struct pwm_device *pwm)
+{
+       mutex_lock(&pwm_lock);
+       list_add_tail(&pwm->node, &pwm_list);
+       mutex_unlock(&pwm_lock);
+}
+
+static struct pwm_device *pwm_probe(struct platform_device *pdev,
+               unsigned int pwm_id, struct pwm_device *parent_pwm)
+{
+       struct pwm_device *pwm;
+       struct resource *r;
+       int ret = 0;
+
+       pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL);
+       if (pwm == NULL) {
+               dev_err(&pdev->dev, "failed to allocate memory\n");
+               return ERR_PTR(-ENOMEM);
+       }
+
+       pwm->clk = clk_get(NULL, "OST_CLK");
+       if (IS_ERR(pwm->clk)) {
+               ret = PTR_ERR(pwm->clk);
+               goto err_free;
+       }
+       pwm->clk_enabled = 0;
+
+       pwm->use_count = 0;
+       pwm->pwm_id = pwm_id;
+       pwm->pdev = pdev;
+
+       r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (r == NULL) {
+               dev_err(&pdev->dev, "no memory resource defined\n");
+               ret = -ENODEV;
+               goto err_free_clk;
+       }
+
+       r = request_mem_region(r->start, resource_size(r), pdev->name);
+       if (r == NULL) {
+               dev_err(&pdev->dev, "failed to request memory resource\n");
+               ret = -EBUSY;
+               goto err_free_clk;
+       }
+
+       __add_pwm(pwm);
+       platform_set_drvdata(pdev, pwm);
+       return pwm;
+
+err_free_clk:
+       clk_put(pwm->clk);
+err_free:
+       kfree(pwm);
+       return ERR_PTR(ret);
+}
+
+static int __devinit puv3_pwm_probe(struct platform_device *pdev)
+{
+       struct pwm_device *pwm = pwm_probe(pdev, pdev->id, NULL);
+
+       if (IS_ERR(pwm))
+               return PTR_ERR(pwm);
+
+       return 0;
+}
+
+static int __devexit pwm_remove(struct platform_device *pdev)
+{
+       struct pwm_device *pwm;
+       struct resource *r;
+
+       pwm = platform_get_drvdata(pdev);
+       if (pwm == NULL)
+               return -ENODEV;
+
+       mutex_lock(&pwm_lock);
+       list_del(&pwm->node);
+       mutex_unlock(&pwm_lock);
+
+       r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       release_mem_region(r->start, resource_size(r));
+
+       clk_put(pwm->clk);
+       kfree(pwm);
+       return 0;
+}
+
+static struct platform_driver puv3_pwm_driver = {
+       .driver         = {
+               .name   = "PKUnity-v3-PWM",
+       },
+       .probe          = puv3_pwm_probe,
+       .remove         = __devexit_p(pwm_remove),
+};
+
+static int __init pwm_init(void)
+{
+       int ret = 0;
+
+       ret = platform_driver_register(&puv3_pwm_driver);
+       if (ret) {
+               printk(KERN_ERR "failed to register puv3_pwm_driver\n");
+               return ret;
+       }
+
+       return ret;
+}
+arch_initcall(pwm_init);
+
+static void __exit pwm_exit(void)
+{
+       platform_driver_unregister(&puv3_pwm_driver);
+}
+module_exit(pwm_exit);
+
+MODULE_LICENSE("GPL v2");
diff --git a/arch/unicore32/kernel/rtc.c b/arch/unicore32/kernel/rtc.c
new file mode 100644 (file)
index 0000000..5e4db41
--- /dev/null
@@ -0,0 +1,380 @@
+/*
+ * linux/arch/unicore32/kernel/rtc.c
+ *
+ * Code specific to PKUnity SoC and UniCore ISA
+ *
+ *     Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn>
+ *     Copyright (C) 2001-2010 Guan Xuetao
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/string.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/rtc.h>
+#include <linux/bcd.h>
+#include <linux/clk.h>
+#include <linux/log2.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+
+#include <asm/irq.h>
+#include <mach/hardware.h>
+
+static struct resource *puv3_rtc_mem;
+
+static int puv3_rtc_alarmno = IRQ_RTCAlarm;
+static int puv3_rtc_tickno  = IRQ_RTC;
+
+static DEFINE_SPINLOCK(puv3_rtc_pie_lock);
+
+/* IRQ Handlers */
+
+static irqreturn_t puv3_rtc_alarmirq(int irq, void *id)
+{
+       struct rtc_device *rdev = id;
+
+       RTC_RTSR |= RTC_RTSR_AL;
+       rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF);
+       return IRQ_HANDLED;
+}
+
+static irqreturn_t puv3_rtc_tickirq(int irq, void *id)
+{
+       struct rtc_device *rdev = id;
+
+       RTC_RTSR |= RTC_RTSR_HZ;
+       rtc_update_irq(rdev, 1, RTC_PF | RTC_IRQF);
+       return IRQ_HANDLED;
+}
+
+/* Update control registers */
+static void puv3_rtc_setaie(int to)
+{
+       unsigned int tmp;
+
+       pr_debug("%s: aie=%d\n", __func__, to);
+
+       tmp = RTC_RTSR & ~RTC_RTSR_ALE;
+
+       if (to)
+               tmp |= RTC_RTSR_ALE;
+
+       RTC_RTSR = tmp;
+}
+
+static int puv3_rtc_setpie(struct device *dev, int enabled)
+{
+       unsigned int tmp;
+
+       pr_debug("%s: pie=%d\n", __func__, enabled);
+
+       spin_lock_irq(&puv3_rtc_pie_lock);
+       tmp = RTC_RTSR & ~RTC_RTSR_HZE;
+
+       if (enabled)
+               tmp |= RTC_RTSR_HZE;
+
+       RTC_RTSR = tmp;
+       spin_unlock_irq(&puv3_rtc_pie_lock);
+
+       return 0;
+}
+
+static int puv3_rtc_setfreq(struct device *dev, int freq)
+{
+       return 0;
+}
+
+/* Time read/write */
+
+static int puv3_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
+{
+       rtc_time_to_tm(RTC_RCNR, rtc_tm);
+
+       pr_debug("read time %02x.%02x.%02x %02x/%02x/%02x\n",
+                rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
+                rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
+
+       return 0;
+}
+
+static int puv3_rtc_settime(struct device *dev, struct rtc_time *tm)
+{
+       unsigned long rtc_count = 0;
+
+       pr_debug("set time %02d.%02d.%02d %02d/%02d/%02d\n",
+                tm->tm_year, tm->tm_mon, tm->tm_mday,
+                tm->tm_hour, tm->tm_min, tm->tm_sec);
+
+       rtc_tm_to_time(tm, &rtc_count);
+       RTC_RCNR = rtc_count;
+
+       return 0;
+}
+
+static int puv3_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+       struct rtc_time *alm_tm = &alrm->time;
+
+       rtc_time_to_tm(RTC_RTAR, alm_tm);
+
+       alrm->enabled = RTC_RTSR & RTC_RTSR_ALE;
+
+       pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
+                alrm->enabled,
+                alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
+                alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
+
+       return 0;
+}
+
+static int puv3_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+       struct rtc_time *tm = &alrm->time;
+       unsigned long rtcalarm_count = 0;
+
+       pr_debug("puv3_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n",
+                alrm->enabled,
+                tm->tm_mday & 0xff, tm->tm_mon & 0xff, tm->tm_year & 0xff,
+                tm->tm_hour & 0xff, tm->tm_min & 0xff, tm->tm_sec);
+
+       rtc_tm_to_time(tm, &rtcalarm_count);
+       RTC_RTAR = rtcalarm_count;
+
+       puv3_rtc_setaie(alrm->enabled);
+
+       if (alrm->enabled)
+               enable_irq_wake(puv3_rtc_alarmno);
+       else
+               disable_irq_wake(puv3_rtc_alarmno);
+
+       return 0;
+}
+
+static int puv3_rtc_proc(struct device *dev, struct seq_file *seq)
+{
+       seq_printf(seq, "periodic_IRQ\t: %s\n",
+                    (RTC_RTSR & RTC_RTSR_HZE) ? "yes" : "no");
+       return 0;
+}
+
+static int puv3_rtc_open(struct device *dev)
+{
+       struct platform_device *pdev = to_platform_device(dev);
+       struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
+       int ret;
+
+       ret = request_irq(puv3_rtc_alarmno, puv3_rtc_alarmirq,
+                         IRQF_DISABLED,  "pkunity-rtc alarm", rtc_dev);
+
+       if (ret) {
+               dev_err(dev, "IRQ%d error %d\n", puv3_rtc_alarmno, ret);
+               return ret;
+       }
+
+       ret = request_irq(puv3_rtc_tickno, puv3_rtc_tickirq,
+                         IRQF_DISABLED,  "pkunity-rtc tick", rtc_dev);
+
+       if (ret) {
+               dev_err(dev, "IRQ%d error %d\n", puv3_rtc_tickno, ret);
+               goto tick_err;
+       }
+
+       return ret;
+
+ tick_err:
+       free_irq(puv3_rtc_alarmno, rtc_dev);
+       return ret;
+}
+
+static void puv3_rtc_release(struct device *dev)
+{
+       struct platform_device *pdev = to_platform_device(dev);
+       struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
+
+       /* do not clear AIE here, it may be needed for wake */
+
+       puv3_rtc_setpie(dev, 0);
+       free_irq(puv3_rtc_alarmno, rtc_dev);
+       free_irq(puv3_rtc_tickno, rtc_dev);
+}
+
+static const struct rtc_class_ops puv3_rtcops = {
+       .open           = puv3_rtc_open,
+       .release        = puv3_rtc_release,
+       .read_time      = puv3_rtc_gettime,
+       .set_time       = puv3_rtc_settime,
+       .read_alarm     = puv3_rtc_getalarm,
+       .set_alarm      = puv3_rtc_setalarm,
+       .irq_set_freq   = puv3_rtc_setfreq,
+       .irq_set_state  = puv3_rtc_setpie,
+       .proc           = puv3_rtc_proc,
+};
+
+static void puv3_rtc_enable(struct platform_device *pdev, int en)
+{
+       if (!en) {
+               RTC_RTSR &= ~RTC_RTSR_HZE;
+       } else {
+               /* re-enable the device, and check it is ok */
+
+               if ((RTC_RTSR & RTC_RTSR_HZE) == 0) {
+                       dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
+                       RTC_RTSR |= RTC_RTSR_HZE;
+               }
+       }
+}
+
+static int puv3_rtc_remove(struct platform_device *dev)
+{
+       struct rtc_device *rtc = platform_get_drvdata(dev);
+
+       platform_set_drvdata(dev, NULL);
+       rtc_device_unregister(rtc);
+
+       puv3_rtc_setpie(&dev->dev, 0);
+       puv3_rtc_setaie(0);
+
+       release_resource(puv3_rtc_mem);
+       kfree(puv3_rtc_mem);
+
+       return 0;
+}
+
+static int puv3_rtc_probe(struct platform_device *pdev)
+{
+       struct rtc_device *rtc;
+       struct resource *res;
+       int ret;
+
+       pr_debug("%s: probe=%p\n", __func__, pdev);
+
+       /* find the IRQs */
+
+       puv3_rtc_tickno = platform_get_irq(pdev, 1);
+       if (puv3_rtc_tickno < 0) {
+               dev_err(&pdev->dev, "no irq for rtc tick\n");
+               return -ENOENT;
+       }
+
+       puv3_rtc_alarmno = platform_get_irq(pdev, 0);
+       if (puv3_rtc_alarmno < 0) {
+               dev_err(&pdev->dev, "no irq for alarm\n");
+               return -ENOENT;
+       }
+
+       pr_debug("PKUnity_rtc: tick irq %d, alarm irq %d\n",
+                puv3_rtc_tickno, puv3_rtc_alarmno);
+
+       /* get the memory region */
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (res == NULL) {
+               dev_err(&pdev->dev, "failed to get memory region resource\n");
+               return -ENOENT;
+       }
+
+       puv3_rtc_mem = request_mem_region(res->start,
+                                        res->end-res->start+1,
+                                        pdev->name);
+
+       if (puv3_rtc_mem == NULL) {
+               dev_err(&pdev->dev, "failed to reserve memory region\n");
+               ret = -ENOENT;
+               goto err_nores;
+       }
+
+       puv3_rtc_enable(pdev, 1);
+
+       puv3_rtc_setfreq(&pdev->dev, 1);
+
+       /* register RTC and exit */
+
+       rtc = rtc_device_register("pkunity", &pdev->dev, &puv3_rtcops,
+                                 THIS_MODULE);
+
+       if (IS_ERR(rtc)) {
+               dev_err(&pdev->dev, "cannot attach rtc\n");
+               ret = PTR_ERR(rtc);
+               goto err_nortc;
+       }
+
+       /* platform setup code should have handled this; sigh */
+       if (!device_can_wakeup(&pdev->dev))
+               device_init_wakeup(&pdev->dev, 1);
+
+       platform_set_drvdata(pdev, rtc);
+       return 0;
+
+ err_nortc:
+       puv3_rtc_enable(pdev, 0);
+       release_resource(puv3_rtc_mem);
+
+ err_nores:
+       return ret;
+}
+
+#ifdef CONFIG_PM
+
+/* RTC Power management control */
+
+static int ticnt_save;
+
+static int puv3_rtc_suspend(struct platform_device *pdev, pm_message_t state)
+{
+       /* save RTAR for anyone using periodic interrupts */
+       ticnt_save = RTC_RTAR;
+       puv3_rtc_enable(pdev, 0);
+       return 0;
+}
+
+static int puv3_rtc_resume(struct platform_device *pdev)
+{
+       puv3_rtc_enable(pdev, 1);
+       RTC_RTAR = ticnt_save;
+       return 0;
+}
+#else
+#define puv3_rtc_suspend NULL
+#define puv3_rtc_resume  NULL
+#endif
+
+static struct platform_driver puv3_rtcdrv = {
+       .probe          = puv3_rtc_probe,
+       .remove         = __devexit_p(puv3_rtc_remove),
+       .suspend        = puv3_rtc_suspend,
+       .resume         = puv3_rtc_resume,
+       .driver         = {
+               .name   = "PKUnity-v3-RTC",
+               .owner  = THIS_MODULE,
+       }
+};
+
+static char __initdata banner[] = "PKUnity-v3 RTC, (c) 2009 PKUnity Co.\n";
+
+static int __init puv3_rtc_init(void)
+{
+       printk(banner);
+       return platform_driver_register(&puv3_rtcdrv);
+}
+
+static void __exit puv3_rtc_exit(void)
+{
+       platform_driver_unregister(&puv3_rtcdrv);
+}
+
+module_init(puv3_rtc_init);
+module_exit(puv3_rtc_exit);
+
+MODULE_DESCRIPTION("RTC Driver for the PKUnity v3 chip");
+MODULE_AUTHOR("Hu Dongliang");
+MODULE_LICENSE("GPL v2");
+
diff --git a/arch/unicore32/kernel/time.c b/arch/unicore32/kernel/time.c
new file mode 100644 (file)
index 0000000..8090d76
--- /dev/null
@@ -0,0 +1,148 @@
+/*
+ * linux/arch/unicore32/kernel/time.c
+ *
+ * Code specific to PKUnity SoC and UniCore ISA
+ *
+ *     Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn>
+ *     Copyright (C) 2001-2010 Guan Xuetao
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/timex.h>
+#include <linux/clockchips.h>
+
+#include <mach/hardware.h>
+
+#define MIN_OSCR_DELTA 2
+
+static irqreturn_t puv3_ost0_interrupt(int irq, void *dev_id)
+{
+       struct clock_event_device *c = dev_id;
+
+       /* Disarm the compare/match, signal the event. */
+       OST_OIER &= ~OST_OIER_E0;
+       OST_OSSR &= ~OST_OSSR_M0;
+       c->event_handler(c);
+
+       return IRQ_HANDLED;
+}
+
+static int
+puv3_osmr0_set_next_event(unsigned long delta, struct clock_event_device *c)
+{
+       unsigned long next, oscr;
+
+       OST_OIER |= OST_OIER_E0;
+       next = OST_OSCR + delta;
+       OST_OSMR0 = next;
+       oscr = OST_OSCR;
+
+       return (signed)(next - oscr) <= MIN_OSCR_DELTA ? -ETIME : 0;
+}
+
+static void
+puv3_osmr0_set_mode(enum clock_event_mode mode, struct clock_event_device *c)
+{
+       switch (mode) {
+       case CLOCK_EVT_MODE_ONESHOT:
+       case CLOCK_EVT_MODE_UNUSED:
+       case CLOCK_EVT_MODE_SHUTDOWN:
+               OST_OIER &= ~OST_OIER_E0;
+               OST_OSSR &= ~OST_OSSR_M0;
+               break;
+
+       case CLOCK_EVT_MODE_RESUME:
+       case CLOCK_EVT_MODE_PERIODIC:
+               break;
+       }
+}
+
+static struct clock_event_device ckevt_puv3_osmr0 = {
+       .name           = "osmr0",
+       .features       = CLOCK_EVT_FEAT_ONESHOT,
+#ifdef CONFIG_ARCH_FPGA
+       .shift          = 18, /* correct shift val: 16, but warn_on_slowpath */
+#else
+       .shift          = 30,
+#endif
+       .rating         = 200,
+       .set_next_event = puv3_osmr0_set_next_event,
+       .set_mode       = puv3_osmr0_set_mode,
+};
+
+static cycle_t puv3_read_oscr(struct clocksource *cs)
+{
+       return OST_OSCR;
+}
+
+static struct clocksource cksrc_puv3_oscr = {
+       .name           = "oscr",
+       .rating         = 200,
+       .read           = puv3_read_oscr,
+       .mask           = CLOCKSOURCE_MASK(32),
+       .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static struct irqaction puv3_timer_irq = {
+       .name           = "ost0",
+       .flags          = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
+       .handler        = puv3_ost0_interrupt,
+       .dev_id         = &ckevt_puv3_osmr0,
+};
+
+void __init time_init(void)
+{
+       OST_OIER = 0;           /* disable any timer interrupts */
+       OST_OSSR = 0;           /* clear status on all timers */
+
+       ckevt_puv3_osmr0.mult =
+               div_sc(CLOCK_TICK_RATE, NSEC_PER_SEC, ckevt_puv3_osmr0.shift);
+       ckevt_puv3_osmr0.max_delta_ns =
+               clockevent_delta2ns(0x7fffffff, &ckevt_puv3_osmr0);
+       ckevt_puv3_osmr0.min_delta_ns =
+               clockevent_delta2ns(MIN_OSCR_DELTA * 2, &ckevt_puv3_osmr0) + 1;
+       ckevt_puv3_osmr0.cpumask = cpumask_of(0);
+
+       setup_irq(IRQ_TIMER0, &puv3_timer_irq);
+
+       clocksource_register_hz(&cksrc_puv3_oscr, CLOCK_TICK_RATE);
+       clockevents_register_device(&ckevt_puv3_osmr0);
+}
+
+#ifdef CONFIG_PM
+unsigned long osmr[4], oier;
+
+void puv3_timer_suspend(void)
+{
+       osmr[0] = OST_OSMR0;
+       osmr[1] = OST_OSMR1;
+       osmr[2] = OST_OSMR2;
+       osmr[3] = OST_OSMR3;
+       oier = OST_OIER;
+}
+
+void puv3_timer_resume(void)
+{
+       OST_OSSR = 0;
+       OST_OSMR0 = osmr[0];
+       OST_OSMR1 = osmr[1];
+       OST_OSMR2 = osmr[2];
+       OST_OSMR3 = osmr[3];
+       OST_OIER = oier;
+
+       /*
+        * OSMR0 is the system timer: make sure OSCR is sufficiently behind
+        */
+       OST_OSCR = OST_OSMR0 - LATCH;
+}
+#else
+void puv3_timer_suspend(void) { };
+void puv3_timer_resume(void) { };
+#endif
+