drivers/rtc/rtc-as3722.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * rtc-as3722.c - Real Time Clock driver for ams AS3722 PMICs
   4  *
   5  * Copyright (C) 2013 ams AG
   6  * Copyright (c) 2013, NVIDIA Corporation. All rights reserved.
   7  *
   8  * Author: Florian Lobmaier <florian.lobmaier@ams.com>
   9  * Author: Laxman Dewangan <ldewangan@nvidia.com>
  10  */
  11
  12 #include <linux/bcd.h>
  13 #include <linux/completion.h>
  14 #include <linux/delay.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/ioctl.h>
  17 #include <linux/kernel.h>
  18 #include <linux/module.h>
  19 #include <linux/mfd/as3722.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/rtc.h>
  22 #include <linux/time.h>
  23
  24 #define AS3722_RTC_START_YEAR     2000
  25 struct as3722_rtc {
  26         struct rtc_device       *rtc;
  27         struct device           *dev;
  28         struct as3722           *as3722;
  29         int                     alarm_irq;
  30         bool                    irq_enable;
  31 };
  32
  33 static void as3722_time_to_reg(u8 *rbuff, struct rtc_time *tm)
  34 {
  35         rbuff[0] = bin2bcd(tm->tm_sec);
  36         rbuff[1] = bin2bcd(tm->tm_min);
  37         rbuff[2] = bin2bcd(tm->tm_hour);
  38         rbuff[3] = bin2bcd(tm->tm_mday);
  39         rbuff[4] = bin2bcd(tm->tm_mon + 1);
  40         rbuff[5] = bin2bcd(tm->tm_year - (AS3722_RTC_START_YEAR - 1900));
  41 }
  42
  43 static void as3722_reg_to_time(u8 *rbuff, struct rtc_time *tm)
  44 {
  45         tm->tm_sec = bcd2bin(rbuff[0] & 0x7F);
  46         tm->tm_min = bcd2bin(rbuff[1] & 0x7F);
  47         tm->tm_hour = bcd2bin(rbuff[2] & 0x3F);
  48         tm->tm_mday = bcd2bin(rbuff[3] & 0x3F);
  49         tm->tm_mon = bcd2bin(rbuff[4] & 0x1F) - 1;
  50         tm->tm_year = (AS3722_RTC_START_YEAR - 1900) + bcd2bin(rbuff[5] & 0x7F);
  51         return;
  52 }
  53
  54 static int as3722_rtc_read_time(struct device *dev, struct rtc_time *tm)
  55 {
  56         struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
  57         struct as3722 *as3722 = as3722_rtc->as3722;
  58         u8 as_time_array[6];
  59         int ret;
  60
  61         ret = as3722_block_read(as3722, AS3722_RTC_SECOND_REG,
  62                         6, as_time_array);
  63         if (ret < 0) {
  64                 dev_err(dev, "RTC_SECOND reg block read failed %d\n", ret);
  65                 return ret;
  66         }
  67         as3722_reg_to_time(as_time_array, tm);
  68         return 0;
  69 }
  70
  71 static int as3722_rtc_set_time(struct device *dev, struct rtc_time *tm)
  72 {
  73         struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
  74         struct as3722 *as3722 = as3722_rtc->as3722;
  75         u8 as_time_array[6];
  76         int ret;
  77
  78         if (tm->tm_year < (AS3722_RTC_START_YEAR - 1900))
  79                 return -EINVAL;
  80
  81         as3722_time_to_reg(as_time_array, tm);
  82         ret = as3722_block_write(as3722, AS3722_RTC_SECOND_REG, 6,
  83                         as_time_array);
  84         if (ret < 0)
  85                 dev_err(dev, "RTC_SECOND reg block write failed %d\n", ret);
  86         return ret;
  87 }
  88
  89 static int as3722_rtc_alarm_irq_enable(struct device *dev,
  90                 unsigned int enabled)
  91 {
  92         struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
  93
  94         if (enabled && !as3722_rtc->irq_enable) {
  95                 enable_irq(as3722_rtc->alarm_irq);
  96                 as3722_rtc->irq_enable = true;
  97         } else if (!enabled && as3722_rtc->irq_enable)  {
  98                 disable_irq(as3722_rtc->alarm_irq);
  99                 as3722_rtc->irq_enable = false;
 100         }
 101         return 0;
 102 }
 103
 104 static int as3722_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 105 {
 106         struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
 107         struct as3722 *as3722 = as3722_rtc->as3722;
 108         u8 as_time_array[6];
 109         int ret;
 110
 111         ret = as3722_block_read(as3722, AS3722_RTC_ALARM_SECOND_REG, 6,
 112                         as_time_array);
 113         if (ret < 0) {
 114                 dev_err(dev, "RTC_ALARM_SECOND block read failed %d\n", ret);
 115                 return ret;
 116         }
 117
 118         as3722_reg_to_time(as_time_array, &alrm->time);
 119         return 0;
 120 }
 121
 122 static int as3722_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 123 {
 124         struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
 125         struct as3722 *as3722 = as3722_rtc->as3722;
 126         u8 as_time_array[6];
 127         int ret;
 128
 129         if (alrm->time.tm_year < (AS3722_RTC_START_YEAR - 1900))
 130                 return -EINVAL;
 131
 132         ret = as3722_rtc_alarm_irq_enable(dev, 0);
 133         if (ret < 0) {
 134                 dev_err(dev, "Disable RTC alarm failed\n");
 135                 return ret;
 136         }
 137
 138         as3722_time_to_reg(as_time_array, &alrm->time);
 139         ret = as3722_block_write(as3722, AS3722_RTC_ALARM_SECOND_REG, 6,
 140                         as_time_array);
 141         if (ret < 0) {
 142                 dev_err(dev, "RTC_ALARM_SECOND block write failed %d\n", ret);
 143                 return ret;
 144         }
 145
 146         if (alrm->enabled)
 147                 ret = as3722_rtc_alarm_irq_enable(dev, alrm->enabled);
 148         return ret;
 149 }
 150
 151 static irqreturn_t as3722_alarm_irq(int irq, void *data)
 152 {
 153         struct as3722_rtc *as3722_rtc = data;
 154
 155         rtc_update_irq(as3722_rtc->rtc, 1, RTC_IRQF | RTC_AF);
 156         return IRQ_HANDLED;
 157 }
 158
 159 static const struct rtc_class_ops as3722_rtc_ops = {
 160         .read_time = as3722_rtc_read_time,
 161         .set_time = as3722_rtc_set_time,
 162         .read_alarm = as3722_rtc_read_alarm,
 163         .set_alarm = as3722_rtc_set_alarm,
 164         .alarm_irq_enable = as3722_rtc_alarm_irq_enable,
 165 };
 166
 167 static int as3722_rtc_probe(struct platform_device *pdev)
 168 {
 169         struct as3722 *as3722 = dev_get_drvdata(pdev->dev.parent);
 170         struct as3722_rtc *as3722_rtc;
 171         int ret;
 172
 173         as3722_rtc = devm_kzalloc(&pdev->dev, sizeof(*as3722_rtc), GFP_KERNEL);
 174         if (!as3722_rtc)
 175                 return -ENOMEM;
 176
 177         as3722_rtc->as3722 = as3722;
 178         as3722_rtc->dev = &pdev->dev;
 179         platform_set_drvdata(pdev, as3722_rtc);
 180
 181         /* Enable the RTC to make sure it is running. */
 182         ret = as3722_update_bits(as3722, AS3722_RTC_CONTROL_REG,
 183                         AS3722_RTC_ON | AS3722_RTC_ALARM_WAKEUP_EN,
 184                         AS3722_RTC_ON | AS3722_RTC_ALARM_WAKEUP_EN);
 185         if (ret < 0) {
 186                 dev_err(&pdev->dev, "RTC_CONTROL reg write failed: %d\n", ret);
 187                 return ret;
 188         }
 189
 190         device_init_wakeup(&pdev->dev, 1);
 191
 192         as3722_rtc->rtc = devm_rtc_device_register(&pdev->dev, "as3722-rtc",
 193                                 &as3722_rtc_ops, THIS_MODULE);
 194         if (IS_ERR(as3722_rtc->rtc)) {
 195                 ret = PTR_ERR(as3722_rtc->rtc);
 196                 dev_err(&pdev->dev, "RTC register failed: %d\n", ret);
 197                 return ret;
 198         }
 199
 200         as3722_rtc->alarm_irq = platform_get_irq(pdev, 0);
 201         dev_info(&pdev->dev, "RTC interrupt %d\n", as3722_rtc->alarm_irq);
 202
 203         ret = devm_request_threaded_irq(&pdev->dev, as3722_rtc->alarm_irq, NULL,
 204                         as3722_alarm_irq, IRQF_ONESHOT,
 205                         "rtc-alarm", as3722_rtc);
 206         if (ret < 0) {
 207                 dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n",
 208                                 as3722_rtc->alarm_irq, ret);
 209                 return ret;
 210         }
 211         disable_irq(as3722_rtc->alarm_irq);
 212         return 0;
 213 }
 214
 215 #ifdef CONFIG_PM_SLEEP
 216 static int as3722_rtc_suspend(struct device *dev)
 217 {
 218         struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
 219
 220         if (device_may_wakeup(dev))
 221                 enable_irq_wake(as3722_rtc->alarm_irq);
 222
 223         return 0;
 224 }
 225
 226 static int as3722_rtc_resume(struct device *dev)
 227 {
 228         struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
 229
 230         if (device_may_wakeup(dev))
 231                 disable_irq_wake(as3722_rtc->alarm_irq);
 232         return 0;
 233 }
 234 #endif
 235
 236 static SIMPLE_DEV_PM_OPS(as3722_rtc_pm_ops, as3722_rtc_suspend,
 237                          as3722_rtc_resume);
 238
 239 static struct platform_driver as3722_rtc_driver = {
 240         .probe = as3722_rtc_probe,
 241         .driver = {
 242                 .name = "as3722-rtc",
 243                 .pm = &as3722_rtc_pm_ops,
 244         },
 245 };
 246 module_platform_driver(as3722_rtc_driver);
 247
 248 MODULE_DESCRIPTION("RTC driver for AS3722 PMICs");
 249 MODULE_ALIAS("platform:as3722-rtc");
 250 MODULE_AUTHOR("Florian Lobmaier <florian.lobmaier@ams.com>");
 251 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
 252 MODULE_LICENSE("GPL");