drivers/rtc/rtc-pcap.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  pcap rtc code for Motorola EZX phones
   4  *
   5  *  Copyright (c) 2008 guiming zhuo <gmzhuo@gmail.com>
   6  *  Copyright (c) 2009 Daniel Ribeiro <drwyrm@gmail.com>
   7  *
   8  *  Based on Motorola's rtc.c Copyright (c) 2003-2005 Motorola
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/mfd/ezx-pcap.h>
  15 #include <linux/rtc.h>
  16 #include <linux/slab.h>
  17 #include <linux/platform_device.h>
  18
  19 struct pcap_rtc {
  20         struct pcap_chip *pcap;
  21         struct rtc_device *rtc;
  22 };
  23
  24 static irqreturn_t pcap_rtc_irq(int irq, void *_pcap_rtc)
  25 {
  26         struct pcap_rtc *pcap_rtc = _pcap_rtc;
  27         unsigned long rtc_events;
  28
  29         if (irq == pcap_to_irq(pcap_rtc->pcap, PCAP_IRQ_1HZ))
  30                 rtc_events = RTC_IRQF | RTC_UF;
  31         else if (irq == pcap_to_irq(pcap_rtc->pcap, PCAP_IRQ_TODA))
  32                 rtc_events = RTC_IRQF | RTC_AF;
  33         else
  34                 rtc_events = 0;
  35
  36         rtc_update_irq(pcap_rtc->rtc, 1, rtc_events);
  37         return IRQ_HANDLED;
  38 }
  39
  40 static int pcap_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
  41 {
  42         struct pcap_rtc *pcap_rtc = dev_get_drvdata(dev);
  43         struct rtc_time *tm = &alrm->time;
  44         unsigned long secs;
  45         u32 tod;        /* time of day, seconds since midnight */
  46         u32 days;       /* days since 1/1/1970 */
  47
  48         ezx_pcap_read(pcap_rtc->pcap, PCAP_REG_RTC_TODA, &tod);
  49         secs = tod & PCAP_RTC_TOD_MASK;
  50
  51         ezx_pcap_read(pcap_rtc->pcap, PCAP_REG_RTC_DAYA, &days);
  52         secs += (days & PCAP_RTC_DAY_MASK) * SEC_PER_DAY;
  53
  54         rtc_time64_to_tm(secs, tm);
  55
  56         return 0;
  57 }
  58
  59 static int pcap_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
  60 {
  61         struct pcap_rtc *pcap_rtc = dev_get_drvdata(dev);
  62         unsigned long secs = rtc_tm_to_time64(&alrm->time);
  63         u32 tod, days;
  64
  65         tod = secs % SEC_PER_DAY;
  66         ezx_pcap_write(pcap_rtc->pcap, PCAP_REG_RTC_TODA, tod);
  67
  68         days = secs / SEC_PER_DAY;
  69         ezx_pcap_write(pcap_rtc->pcap, PCAP_REG_RTC_DAYA, days);
  70
  71         return 0;
  72 }
  73
  74 static int pcap_rtc_read_time(struct device *dev, struct rtc_time *tm)
  75 {
  76         struct pcap_rtc *pcap_rtc = dev_get_drvdata(dev);
  77         unsigned long secs;
  78         u32 tod, days;
  79
  80         ezx_pcap_read(pcap_rtc->pcap, PCAP_REG_RTC_TOD, &tod);
  81         secs = tod & PCAP_RTC_TOD_MASK;
  82
  83         ezx_pcap_read(pcap_rtc->pcap, PCAP_REG_RTC_DAY, &days);
  84         secs += (days & PCAP_RTC_DAY_MASK) * SEC_PER_DAY;
  85
  86         rtc_time64_to_tm(secs, tm);
  87
  88         return 0;
  89 }
  90
  91 static int pcap_rtc_set_time(struct device *dev, struct rtc_time *tm)
  92 {
  93         struct pcap_rtc *pcap_rtc = dev_get_drvdata(dev);
  94         unsigned long secs = rtc_tm_to_time64(tm);
  95         u32 tod, days;
  96
  97         tod = secs % SEC_PER_DAY;
  98         ezx_pcap_write(pcap_rtc->pcap, PCAP_REG_RTC_TOD, tod);
  99
 100         days = secs / SEC_PER_DAY;
 101         ezx_pcap_write(pcap_rtc->pcap, PCAP_REG_RTC_DAY, days);
 102
 103         return 0;
 104 }
 105
 106 static int pcap_rtc_irq_enable(struct device *dev, int pirq, unsigned int en)
 107 {
 108         struct pcap_rtc *pcap_rtc = dev_get_drvdata(dev);
 109
 110         if (en)
 111                 enable_irq(pcap_to_irq(pcap_rtc->pcap, pirq));
 112         else
 113                 disable_irq(pcap_to_irq(pcap_rtc->pcap, pirq));
 114
 115         return 0;
 116 }
 117
 118 static int pcap_rtc_alarm_irq_enable(struct device *dev, unsigned int en)
 119 {
 120         return pcap_rtc_irq_enable(dev, PCAP_IRQ_TODA, en);
 121 }
 122
 123 static const struct rtc_class_ops pcap_rtc_ops = {
 124         .read_time = pcap_rtc_read_time,
 125         .set_time = pcap_rtc_set_time,
 126         .read_alarm = pcap_rtc_read_alarm,
 127         .set_alarm = pcap_rtc_set_alarm,
 128         .alarm_irq_enable = pcap_rtc_alarm_irq_enable,
 129 };
 130
 131 static int __init pcap_rtc_probe(struct platform_device *pdev)
 132 {
 133         struct pcap_rtc *pcap_rtc;
 134         int timer_irq, alarm_irq;
 135         int err = -ENOMEM;
 136
 137         pcap_rtc = devm_kzalloc(&pdev->dev, sizeof(struct pcap_rtc),
 138                                 GFP_KERNEL);
 139         if (!pcap_rtc)
 140                 return err;
 141
 142         pcap_rtc->pcap = dev_get_drvdata(pdev->dev.parent);
 143
 144         platform_set_drvdata(pdev, pcap_rtc);
 145
 146         pcap_rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
 147         if (IS_ERR(pcap_rtc->rtc))
 148                 return PTR_ERR(pcap_rtc->rtc);
 149
 150         pcap_rtc->rtc->ops = &pcap_rtc_ops;
 151         pcap_rtc->rtc->range_max = (1 << 14) * 86400ULL - 1;
 152
 153         timer_irq = pcap_to_irq(pcap_rtc->pcap, PCAP_IRQ_1HZ);
 154         alarm_irq = pcap_to_irq(pcap_rtc->pcap, PCAP_IRQ_TODA);
 155
 156         err = devm_request_irq(&pdev->dev, timer_irq, pcap_rtc_irq, 0,
 157                                 "RTC Timer", pcap_rtc);
 158         if (err)
 159                 return err;
 160
 161         err = devm_request_irq(&pdev->dev, alarm_irq, pcap_rtc_irq, 0,
 162                                 "RTC Alarm", pcap_rtc);
 163         if (err)
 164                 return err;
 165
 166         return rtc_register_device(pcap_rtc->rtc);
 167 }
 168
 169 static int __exit pcap_rtc_remove(struct platform_device *pdev)
 170 {
 171         return 0;
 172 }
 173
 174 static struct platform_driver pcap_rtc_driver = {
 175         .remove = __exit_p(pcap_rtc_remove),
 176         .driver = {
 177                 .name  = "pcap-rtc",
 178         },
 179 };
 180
 181 module_platform_driver_probe(pcap_rtc_driver, pcap_rtc_probe);
 182
 183 MODULE_DESCRIPTION("Motorola pcap rtc driver");
 184 MODULE_AUTHOR("guiming zhuo <gmzhuo@gmail.com>");
 185 MODULE_LICENSE("GPL");