// SPDX-License-Identifier: GPL-2.0

  /*
   *  pcap rtc code for Motorola EZX phones
   *
   *  Copyright (c) 2008 guiming zhuo <gmzhuo@gmail.com>
   *  Copyright (c) 2009 Daniel Ribeiro <drwyrm@gmail.com>
   *
   *  Based on Motorola's rtc.c Copyright (c) 2003-2005 Motorola

   */
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/mfd/ezx-pcap.h>
  #include <linux/rtc.h>

  #include <linux/slab.h>

  #include <linux/platform_device.h>
  
  struct pcap_rtc {
  	struct pcap_chip *pcap;
  	struct rtc_device *rtc;
  };
  
  static irqreturn_t pcap_rtc_irq(int irq, void *_pcap_rtc)
  {
  	struct pcap_rtc *pcap_rtc = _pcap_rtc;
  	unsigned long rtc_events;
  
  	if (irq == pcap_to_irq(pcap_rtc->pcap, PCAP_IRQ_1HZ))
  		rtc_events = RTC_IRQF | RTC_UF;
  	else if (irq == pcap_to_irq(pcap_rtc->pcap, PCAP_IRQ_TODA))
  		rtc_events = RTC_IRQF | RTC_AF;
  	else
  		rtc_events = 0;
  
  	rtc_update_irq(pcap_rtc->rtc, 1, rtc_events);
  	return IRQ_HANDLED;
  }
  
  static int pcap_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
  {

  	struct pcap_rtc *pcap_rtc = dev_get_drvdata(dev);

  	struct rtc_time *tm = &alrm->time;
  	unsigned long secs;
  	u32 tod;	/* time of day, seconds since midnight */
  	u32 days;	/* days since 1/1/1970 */
  
  	ezx_pcap_read(pcap_rtc->pcap, PCAP_REG_RTC_TODA, &tod);
  	secs = tod & PCAP_RTC_TOD_MASK;
  
  	ezx_pcap_read(pcap_rtc->pcap, PCAP_REG_RTC_DAYA, &days);
  	secs += (days & PCAP_RTC_DAY_MASK) * SEC_PER_DAY;

  	rtc_time64_to_tm(secs, tm);

  
  	return 0;
  }
  
  static int pcap_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
  {

  	struct pcap_rtc *pcap_rtc = dev_get_drvdata(dev);

  	unsigned long secs = rtc_tm_to_time64(&alrm->time);

  	u32 tod, days;

  	tod = secs % SEC_PER_DAY;
  	ezx_pcap_write(pcap_rtc->pcap, PCAP_REG_RTC_TODA, tod);
  
  	days = secs / SEC_PER_DAY;
  	ezx_pcap_write(pcap_rtc->pcap, PCAP_REG_RTC_DAYA, days);
  
  	return 0;
  }
  
  static int pcap_rtc_read_time(struct device *dev, struct rtc_time *tm)
  {

  	struct pcap_rtc *pcap_rtc = dev_get_drvdata(dev);

  	unsigned long secs;
  	u32 tod, days;
  
  	ezx_pcap_read(pcap_rtc->pcap, PCAP_REG_RTC_TOD, &tod);
  	secs = tod & PCAP_RTC_TOD_MASK;
  
  	ezx_pcap_read(pcap_rtc->pcap, PCAP_REG_RTC_DAY, &days);
  	secs += (days & PCAP_RTC_DAY_MASK) * SEC_PER_DAY;

  	rtc_time64_to_tm(secs, tm);

  	return 0;

  }

  static int pcap_rtc_set_time(struct device *dev, struct rtc_time *tm)

  {

  	struct pcap_rtc *pcap_rtc = dev_get_drvdata(dev);

  	unsigned long secs = rtc_tm_to_time64(tm);

  	u32 tod, days;
  
  	tod = secs % SEC_PER_DAY;
  	ezx_pcap_write(pcap_rtc->pcap, PCAP_REG_RTC_TOD, tod);
  
  	days = secs / SEC_PER_DAY;
  	ezx_pcap_write(pcap_rtc->pcap, PCAP_REG_RTC_DAY, days);
  
  	return 0;
  }
  
  static int pcap_rtc_irq_enable(struct device *dev, int pirq, unsigned int en)
  {

  	struct pcap_rtc *pcap_rtc = dev_get_drvdata(dev);

  
  	if (en)
  		enable_irq(pcap_to_irq(pcap_rtc->pcap, pirq));
  	else
  		disable_irq(pcap_to_irq(pcap_rtc->pcap, pirq));
  
  	return 0;
  }
  
  static int pcap_rtc_alarm_irq_enable(struct device *dev, unsigned int en)
  {
  	return pcap_rtc_irq_enable(dev, PCAP_IRQ_TODA, en);
  }

  static const struct rtc_class_ops pcap_rtc_ops = {
  	.read_time = pcap_rtc_read_time,

  	.set_time = pcap_rtc_set_time,

  	.read_alarm = pcap_rtc_read_alarm,
  	.set_alarm = pcap_rtc_set_alarm,

  	.alarm_irq_enable = pcap_rtc_alarm_irq_enable,

  };

  static int __init pcap_rtc_probe(struct platform_device *pdev)

  {
  	struct pcap_rtc *pcap_rtc;
  	int timer_irq, alarm_irq;
  	int err = -ENOMEM;

  	pcap_rtc = devm_kzalloc(&pdev->dev, sizeof(struct pcap_rtc),
  				GFP_KERNEL);

  	if (!pcap_rtc)
  		return err;
  
  	pcap_rtc->pcap = dev_get_drvdata(pdev->dev.parent);

  	platform_set_drvdata(pdev, pcap_rtc);

  	pcap_rtc->rtc = devm_rtc_allocate_device(&pdev->dev);

  	if (IS_ERR(pcap_rtc->rtc))
  		return PTR_ERR(pcap_rtc->rtc);

  	pcap_rtc->rtc->ops = &pcap_rtc_ops;
  	pcap_rtc->rtc->range_max = (1 << 14) * 86400ULL - 1;

  	timer_irq = pcap_to_irq(pcap_rtc->pcap, PCAP_IRQ_1HZ);
  	alarm_irq = pcap_to_irq(pcap_rtc->pcap, PCAP_IRQ_TODA);

  	err = devm_request_irq(&pdev->dev, timer_irq, pcap_rtc_irq, 0,
  				"RTC Timer", pcap_rtc);

  	if (err)

  		return err;

  	err = devm_request_irq(&pdev->dev, alarm_irq, pcap_rtc_irq, 0,
  				"RTC Alarm", pcap_rtc);

  	if (err)

  		return err;

  	return rtc_register_device(pcap_rtc->rtc);

  }

  static int __exit pcap_rtc_remove(struct platform_device *pdev)

  {

  	return 0;
  }
  
  static struct platform_driver pcap_rtc_driver = {

  	.remove = __exit_p(pcap_rtc_remove),

  	.driver = {
  		.name  = "pcap-rtc",

  	},
  };

  module_platform_driver_probe(pcap_rtc_driver, pcap_rtc_probe);

  
  MODULE_DESCRIPTION("Motorola pcap rtc driver");
  MODULE_AUTHOR("guiming zhuo <gmzhuo@gmail.com>");
  MODULE_LICENSE("GPL");