unicore32 core architecture: timer and time handling

This patch implements timer and time.
RTC and PWM device drivers are also here.

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

1 files changed, 380 insertions, 0 deletions

diff --git a/arch/unicore32/kernel/rtc.c b/arch/unicore32/kernel/rtc.c
new file mode 100644
index 000000000000..5e4db4158589
--- /dev/null
+++ b/arch/unicore32/kernel/rtc.c
@@ -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");
+