drivers/rtc/rtc-pcf50633.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* NXP PCF50633 RTC Driver
   3  *
   4  * (C) 2006-2008 by Openmoko, Inc.
   5  * Author: Balaji Rao <balajirrao@openmoko.org>
   6  * All rights reserved.
   7  *
   8  * Broken down from monstrous PCF50633 driver mainly by
   9  * Harald Welte, Andy Green and Werner Almesberger
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15 #include <linux/device.h>
  16 #include <linux/slab.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/rtc.h>
  19 #include <linux/bcd.h>
  20 #include <linux/err.h>
  21
  22 #include <linux/mfd/pcf50633/core.h>
  23
  24 #define PCF50633_REG_RTCSC      0x59 /* Second */
  25 #define PCF50633_REG_RTCMN      0x5a /* Minute */
  26 #define PCF50633_REG_RTCHR      0x5b /* Hour */
  27 #define PCF50633_REG_RTCWD      0x5c /* Weekday */
  28 #define PCF50633_REG_RTCDT      0x5d /* Day */
  29 #define PCF50633_REG_RTCMT      0x5e /* Month */
  30 #define PCF50633_REG_RTCYR      0x5f /* Year */
  31 #define PCF50633_REG_RTCSCA     0x60 /* Alarm Second */
  32 #define PCF50633_REG_RTCMNA     0x61 /* Alarm Minute */
  33 #define PCF50633_REG_RTCHRA     0x62 /* Alarm Hour */
  34 #define PCF50633_REG_RTCWDA     0x63 /* Alarm Weekday */
  35 #define PCF50633_REG_RTCDTA     0x64 /* Alarm Day */
  36 #define PCF50633_REG_RTCMTA     0x65 /* Alarm Month */
  37 #define PCF50633_REG_RTCYRA     0x66 /* Alarm Year */
  38
  39 enum pcf50633_time_indexes {
  40         PCF50633_TI_SEC,
  41         PCF50633_TI_MIN,
  42         PCF50633_TI_HOUR,
  43         PCF50633_TI_WKDAY,
  44         PCF50633_TI_DAY,
  45         PCF50633_TI_MONTH,
  46         PCF50633_TI_YEAR,
  47         PCF50633_TI_EXTENT /* always last */
  48 };
  49
  50 struct pcf50633_time {
  51         u_int8_t time[PCF50633_TI_EXTENT];
  52 };
  53
  54 struct pcf50633_rtc {
  55         int alarm_enabled;
  56         int alarm_pending;
  57
  58         struct pcf50633 *pcf;
  59         struct rtc_device *rtc_dev;
  60 };
  61
  62 static void pcf2rtc_time(struct rtc_time *rtc, struct pcf50633_time *pcf)
  63 {
  64         rtc->tm_sec = bcd2bin(pcf->time[PCF50633_TI_SEC]);
  65         rtc->tm_min = bcd2bin(pcf->time[PCF50633_TI_MIN]);
  66         rtc->tm_hour = bcd2bin(pcf->time[PCF50633_TI_HOUR]);
  67         rtc->tm_wday = bcd2bin(pcf->time[PCF50633_TI_WKDAY]);
  68         rtc->tm_mday = bcd2bin(pcf->time[PCF50633_TI_DAY]);
  69         rtc->tm_mon = bcd2bin(pcf->time[PCF50633_TI_MONTH]) - 1;
  70         rtc->tm_year = bcd2bin(pcf->time[PCF50633_TI_YEAR]) + 100;
  71 }
  72
  73 static void rtc2pcf_time(struct pcf50633_time *pcf, struct rtc_time *rtc)
  74 {
  75         pcf->time[PCF50633_TI_SEC] = bin2bcd(rtc->tm_sec);
  76         pcf->time[PCF50633_TI_MIN] = bin2bcd(rtc->tm_min);
  77         pcf->time[PCF50633_TI_HOUR] = bin2bcd(rtc->tm_hour);
  78         pcf->time[PCF50633_TI_WKDAY] = bin2bcd(rtc->tm_wday);
  79         pcf->time[PCF50633_TI_DAY] = bin2bcd(rtc->tm_mday);
  80         pcf->time[PCF50633_TI_MONTH] = bin2bcd(rtc->tm_mon + 1);
  81         pcf->time[PCF50633_TI_YEAR] = bin2bcd(rtc->tm_year % 100);
  82 }
  83
  84 static int
  85 pcf50633_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
  86 {
  87         struct pcf50633_rtc *rtc = dev_get_drvdata(dev);
  88         int err;
  89
  90         if (enabled)
  91                 err = pcf50633_irq_unmask(rtc->pcf, PCF50633_IRQ_ALARM);
  92         else
  93                 err = pcf50633_irq_mask(rtc->pcf, PCF50633_IRQ_ALARM);
  94
  95         if (err < 0)
  96                 return err;
  97
  98         rtc->alarm_enabled = enabled;
  99
 100         return 0;
 101 }
 102
 103 static int pcf50633_rtc_read_time(struct device *dev, struct rtc_time *tm)
 104 {
 105         struct pcf50633_rtc *rtc;
 106         struct pcf50633_time pcf_tm;
 107         int ret;
 108
 109         rtc = dev_get_drvdata(dev);
 110
 111         ret = pcf50633_read_block(rtc->pcf, PCF50633_REG_RTCSC,
 112                                             PCF50633_TI_EXTENT,
 113                                             &pcf_tm.time[0]);
 114         if (ret != PCF50633_TI_EXTENT) {
 115                 dev_err(dev, "Failed to read time\n");
 116                 return -EIO;
 117         }
 118
 119         dev_dbg(dev, "PCF_TIME: %02x.%02x.%02x %02x:%02x:%02x\n",
 120                 pcf_tm.time[PCF50633_TI_DAY],
 121                 pcf_tm.time[PCF50633_TI_MONTH],
 122                 pcf_tm.time[PCF50633_TI_YEAR],
 123                 pcf_tm.time[PCF50633_TI_HOUR],
 124                 pcf_tm.time[PCF50633_TI_MIN],
 125                 pcf_tm.time[PCF50633_TI_SEC]);
 126
 127         pcf2rtc_time(tm, &pcf_tm);
 128
 129         dev_dbg(dev, "RTC_TIME: %ptRr\n", tm);
 130
 131         return 0;
 132 }
 133
 134 static int pcf50633_rtc_set_time(struct device *dev, struct rtc_time *tm)
 135 {
 136         struct pcf50633_rtc *rtc;
 137         struct pcf50633_time pcf_tm;
 138         int alarm_masked, ret = 0;
 139
 140         rtc = dev_get_drvdata(dev);
 141
 142         dev_dbg(dev, "RTC_TIME: %ptRr\n", tm);
 143
 144         rtc2pcf_time(&pcf_tm, tm);
 145
 146         dev_dbg(dev, "PCF_TIME: %02x.%02x.%02x %02x:%02x:%02x\n",
 147                 pcf_tm.time[PCF50633_TI_DAY],
 148                 pcf_tm.time[PCF50633_TI_MONTH],
 149                 pcf_tm.time[PCF50633_TI_YEAR],
 150                 pcf_tm.time[PCF50633_TI_HOUR],
 151                 pcf_tm.time[PCF50633_TI_MIN],
 152                 pcf_tm.time[PCF50633_TI_SEC]);
 153
 154
 155         alarm_masked = pcf50633_irq_mask_get(rtc->pcf, PCF50633_IRQ_ALARM);
 156
 157         if (!alarm_masked)
 158                 pcf50633_irq_mask(rtc->pcf, PCF50633_IRQ_ALARM);
 159
 160         /* Returns 0 on success */
 161         ret = pcf50633_write_block(rtc->pcf, PCF50633_REG_RTCSC,
 162                                              PCF50633_TI_EXTENT,
 163                                              &pcf_tm.time[0]);
 164
 165         if (!alarm_masked)
 166                 pcf50633_irq_unmask(rtc->pcf, PCF50633_IRQ_ALARM);
 167
 168         return ret;
 169 }
 170
 171 static int pcf50633_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 172 {
 173         struct pcf50633_rtc *rtc;
 174         struct pcf50633_time pcf_tm;
 175         int ret = 0;
 176
 177         rtc = dev_get_drvdata(dev);
 178
 179         alrm->enabled = rtc->alarm_enabled;
 180         alrm->pending = rtc->alarm_pending;
 181
 182         ret = pcf50633_read_block(rtc->pcf, PCF50633_REG_RTCSCA,
 183                                 PCF50633_TI_EXTENT, &pcf_tm.time[0]);
 184         if (ret != PCF50633_TI_EXTENT) {
 185                 dev_err(dev, "Failed to read time\n");
 186                 return -EIO;
 187         }
 188
 189         pcf2rtc_time(&alrm->time, &pcf_tm);
 190
 191         return rtc_valid_tm(&alrm->time);
 192 }
 193
 194 static int pcf50633_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 195 {
 196         struct pcf50633_rtc *rtc;
 197         struct pcf50633_time pcf_tm;
 198         int alarm_masked, ret = 0;
 199
 200         rtc = dev_get_drvdata(dev);
 201
 202         rtc2pcf_time(&pcf_tm, &alrm->time);
 203
 204         /* do like mktime does and ignore tm_wday */
 205         pcf_tm.time[PCF50633_TI_WKDAY] = 7;
 206
 207         alarm_masked = pcf50633_irq_mask_get(rtc->pcf, PCF50633_IRQ_ALARM);
 208
 209         /* disable alarm interrupt */
 210         if (!alarm_masked)
 211                 pcf50633_irq_mask(rtc->pcf, PCF50633_IRQ_ALARM);
 212
 213         /* Returns 0 on success */
 214         ret = pcf50633_write_block(rtc->pcf, PCF50633_REG_RTCSCA,
 215                                 PCF50633_TI_EXTENT, &pcf_tm.time[0]);
 216         if (!alrm->enabled)
 217                 rtc->alarm_pending = 0;
 218
 219         if (!alarm_masked || alrm->enabled)
 220                 pcf50633_irq_unmask(rtc->pcf, PCF50633_IRQ_ALARM);
 221         rtc->alarm_enabled = alrm->enabled;
 222
 223         return ret;
 224 }
 225
 226 static const struct rtc_class_ops pcf50633_rtc_ops = {
 227         .read_time              = pcf50633_rtc_read_time,
 228         .set_time               = pcf50633_rtc_set_time,
 229         .read_alarm             = pcf50633_rtc_read_alarm,
 230         .set_alarm              = pcf50633_rtc_set_alarm,
 231         .alarm_irq_enable       = pcf50633_rtc_alarm_irq_enable,
 232 };
 233
 234 static void pcf50633_rtc_irq(int irq, void *data)
 235 {
 236         struct pcf50633_rtc *rtc = data;
 237
 238         rtc_update_irq(rtc->rtc_dev, 1, RTC_AF | RTC_IRQF);
 239         rtc->alarm_pending = 1;
 240 }
 241
 242 static int pcf50633_rtc_probe(struct platform_device *pdev)
 243 {
 244         struct pcf50633_rtc *rtc;
 245
 246         rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
 247         if (!rtc)
 248                 return -ENOMEM;
 249
 250         rtc->pcf = dev_to_pcf50633(pdev->dev.parent);
 251         platform_set_drvdata(pdev, rtc);
 252         rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, "pcf50633-rtc",
 253                                 &pcf50633_rtc_ops, THIS_MODULE);
 254
 255         if (IS_ERR(rtc->rtc_dev))
 256                 return PTR_ERR(rtc->rtc_dev);
 257
 258         pcf50633_register_irq(rtc->pcf, PCF50633_IRQ_ALARM,
 259                                         pcf50633_rtc_irq, rtc);
 260         return 0;
 261 }
 262
 263 static int pcf50633_rtc_remove(struct platform_device *pdev)
 264 {
 265         struct pcf50633_rtc *rtc;
 266
 267         rtc = platform_get_drvdata(pdev);
 268         pcf50633_free_irq(rtc->pcf, PCF50633_IRQ_ALARM);
 269
 270         return 0;
 271 }
 272
 273 static struct platform_driver pcf50633_rtc_driver = {
 274         .driver = {
 275                 .name = "pcf50633-rtc",
 276         },
 277         .probe = pcf50633_rtc_probe,
 278         .remove = pcf50633_rtc_remove,
 279 };
 280
 281 module_platform_driver(pcf50633_rtc_driver);
 282
 283 MODULE_DESCRIPTION("PCF50633 RTC driver");
 284 MODULE_AUTHOR("Balaji Rao <balajirrao@openmoko.org>");
 285 MODULE_LICENSE("GPL");
 286