text: /*
   * RTC driver 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;
  
  	writel(readl(RTC_RTSR) | RTC_RTSR_AL, RTC_RTSR);
  	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;
  
  	writel(readl(RTC_RTSR) | RTC_RTSR_HZ, RTC_RTSR);
  	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 = readl(RTC_RTSR) & ~RTC_RTSR_ALE;
  
  	if (to)
  		tmp |= RTC_RTSR_ALE;
  
  	writel(tmp, RTC_RTSR);
  }
  
  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 = readl(RTC_RTSR) & ~RTC_RTSR_HZE;
  
  	if (enabled)
  		tmp |= RTC_RTSR_HZE;
  
  	writel(tmp, RTC_RTSR);
  	spin_unlock_irq(&puv3_rtc_pie_lock);
  
  	return 0;
  }
  
  /* Time read/write */
  static int puv3_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
  {
  	rtc_time_to_tm(readl(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);
  	writel(rtc_count, RTC_RCNR);
  
  	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(readl(RTC_RTAR), alm_tm);
  
  	alrm->enabled = readl(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);
  	writel(rtcalarm_count, RTC_RTAR);
  
  	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",
  		     (readl(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,
  			0, "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,
  			0, "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,
  	.proc	        = puv3_rtc_proc,
  };
  
  static void puv3_rtc_enable(struct platform_device *pdev, int en)
  {
  	if (!en) {
  		writel(readl(RTC_RTSR) & ~RTC_RTSR_HZE, RTC_RTSR);
  	} else {
  		/* re-enable the device, and check it is ok */
  		if ((readl(RTC_RTSR) & RTC_RTSR_HZE) == 0) {
  			dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
  			writel(readl(RTC_RTSR) | RTC_RTSR_HZE, RTC_RTSR);
  		}
  	}
  }
  
  static int __devexit 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 __devinit 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, resource_size(res),
  					  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);
  
  	/* 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
  
  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 = readl(RTC_RTAR);
  	puv3_rtc_enable(pdev, 0);
  	return 0;
  }
  
  static int puv3_rtc_resume(struct platform_device *pdev)
  {
  	puv3_rtc_enable(pdev, 1);
  	writel(ticnt_save, RTC_RTAR);
  	return 0;
  }
  #else
  #define puv3_rtc_suspend NULL
  #define puv3_rtc_resume  NULL
  #endif
  
  static struct platform_driver puv3_rtc_driver = {
  	.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,
  	}
  };
  
  module_platform_driver(puv3_rtc_driver);
  
  MODULE_DESCRIPTION("RTC Driver for the PKUnity v3 chip");
  MODULE_AUTHOR("Hu Dongliang");
  MODULE_LICENSE("GPL v2");
  