drivers/rtc/rtc-as3722.c

   1 /*
   2  * rtc-as3722.c - Real Time Clock driver for ams AS3722 PMICs
   3  *
   4  * Copyright (C) 2013 ams AG
   5  * Copyright (c) 2013, NVIDIA Corporation. All rights reserved.
   6  *
   7  * Author: Florian Lobmaier <florian.lobmaier@ams.com>
   8  * Author: Laxman Dewangan <ldewangan@nvidia.com>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  */
  20
  21 #include <linux/bcd.h>
  22 #include <linux/completion.h>
  23 #include <linux/delay.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/ioctl.h>
  26 #include <linux/kernel.h>
  27 #include <linux/module.h>
  28 #include <linux/mfd/as3722.h>
  29 #include <linux/platform_device.h>
  30 #include <linux/rtc.h>
  31 #include <linux/time.h>
  32
  33 #define AS3722_RTC_START_YEAR     2000
  34 struct as3722_rtc {
  35         struct rtc_device       *rtc;
  36         struct device           *dev;
  37         struct as3722           *as3722;
  38         int                     alarm_irq;
  39         bool                    irq_enable;
  40 };
  41
  42 static void as3722_time_to_reg(u8 *rbuff, struct rtc_time *tm)
  43 {
  44         rbuff[0] = bin2bcd(tm->tm_sec);
  45         rbuff[1] = bin2bcd(tm->tm_min);
  46         rbuff[2] = bin2bcd(tm->tm_hour);
  47         rbuff[3] = bin2bcd(tm->tm_mday);
  48         rbuff[4] = bin2bcd(tm->tm_mon + 1);
  49         rbuff[5] = bin2bcd(tm->tm_year - (AS3722_RTC_START_YEAR - 1900));
  50 }
  51
  52 static void as3722_reg_to_time(u8 *rbuff, struct rtc_time *tm)
  53 {
  54         tm->tm_sec = bcd2bin(rbuff[0] & 0x7F);
  55         tm->tm_min = bcd2bin(rbuff[1] & 0x7F);
  56         tm->tm_hour = bcd2bin(rbuff[2] & 0x3F);
  57         tm->tm_mday = bcd2bin(rbuff[3] & 0x3F);
  58         tm->tm_mon = bcd2bin(rbuff[4] & 0x1F) - 1;
  59         tm->tm_year = (AS3722_RTC_START_YEAR - 1900) + bcd2bin(rbuff[5] & 0x7F);
  60         return;
  61 }
  62
  63 static int as3722_rtc_read_time(struct device *dev, struct rtc_time *tm)
  64 {
  65         struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
  66         struct as3722 *as3722 = as3722_rtc->as3722;
  67         u8 as_time_array[6];
  68         int ret;
  69
  70         ret = as3722_block_read(as3722, AS3722_RTC_SECOND_REG,
  71                         6, as_time_array);
  72         if (ret < 0) {
  73                 dev_err(dev, "RTC_SECOND reg block read failed %d\n", ret);
  74                 return ret;
  75         }
  76         as3722_reg_to_time(as_time_array, tm);
  77         return 0;
  78 }
  79
  80 static int as3722_rtc_set_time(struct device *dev, struct rtc_time *tm)
  81 {
  82         struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
  83         struct as3722 *as3722 = as3722_rtc->as3722;
  84         u8 as_time_array[6];
  85         int ret;
  86
  87         if (tm->tm_year < (AS3722_RTC_START_YEAR - 1900))
  88                 return -EINVAL;
  89
  90         as3722_time_to_reg(as_time_array, tm);
  91         ret = as3722_block_write(as3722, AS3722_RTC_SECOND_REG, 6,
  92                         as_time_array);
  93         if (ret < 0)
  94                 dev_err(dev, "RTC_SECOND reg block write failed %d\n", ret);
  95         return ret;
  96 }
  97
  98 static int as3722_rtc_alarm_irq_enable(struct device *dev,
  99                 unsigned int enabled)
 100 {
 101         struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
 102
 103         if (enabled && !as3722_rtc->irq_enable) {
 104                 enable_irq(as3722_rtc->alarm_irq);
 105                 as3722_rtc->irq_enable = true;
 106         } else if (!enabled && as3722_rtc->irq_enable)  {
 107                 disable_irq(as3722_rtc->alarm_irq);
 108                 as3722_rtc->irq_enable = false;
 109         }
 110         return 0;
 111 }
 112
 113 static int as3722_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 114 {
 115         struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
 116         struct as3722 *as3722 = as3722_rtc->as3722;
 117         u8 as_time_array[6];
 118         int ret;
 119
 120         ret = as3722_block_read(as3722, AS3722_RTC_ALARM_SECOND_REG, 6,
 121                         as_time_array);
 122         if (ret < 0) {
 123                 dev_err(dev, "RTC_ALARM_SECOND block read failed %d\n", ret);
 124                 return ret;
 125         }
 126
 127         as3722_reg_to_time(as_time_array, &alrm->time);
 128         return 0;
 129 }
 130
 131 static int as3722_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 132 {
 133         struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
 134         struct as3722 *as3722 = as3722_rtc->as3722;
 135         u8 as_time_array[6];
 136         int ret;
 137
 138         if (alrm->time.tm_year < (AS3722_RTC_START_YEAR - 1900))
 139                 return -EINVAL;
 140
 141         ret = as3722_rtc_alarm_irq_enable(dev, 0);
 142         if (ret < 0) {
 143                 dev_err(dev, "Disable RTC alarm failed\n");
 144                 return ret;
 145         }
 146
 147         as3722_time_to_reg(as_time_array, &alrm->time);
 148         ret = as3722_block_write(as3722, AS3722_RTC_ALARM_SECOND_REG, 6,
 149                         as_time_array);
 150         if (ret < 0) {
 151                 dev_err(dev, "RTC_ALARM_SECOND block write failed %d\n", ret);
 152                 return ret;
 153         }
 154
 155         if (alrm->enabled)
 156                 ret = as3722_rtc_alarm_irq_enable(dev, alrm->enabled);
 157         return ret;
 158 }
 159
 160 static irqreturn_t as3722_alarm_irq(int irq, void *data)
 161 {
 162         struct as3722_rtc *as3722_rtc = data;
 163
 164         rtc_update_irq(as3722_rtc->rtc, 1, RTC_IRQF | RTC_AF);
 165         return IRQ_HANDLED;
 166 }
 167
 168 static const struct rtc_class_ops as3722_rtc_ops = {
 169         .read_time = as3722_rtc_read_time,
 170         .set_time = as3722_rtc_set_time,
 171         .read_alarm = as3722_rtc_read_alarm,
 172         .set_alarm = as3722_rtc_set_alarm,
 173         .alarm_irq_enable = as3722_rtc_alarm_irq_enable,
 174 };
 175
 176 static int as3722_rtc_probe(struct platform_device *pdev)
 177 {
 178         struct as3722 *as3722 = dev_get_drvdata(pdev->dev.parent);
 179         struct as3722_rtc *as3722_rtc;
 180         int ret;
 181
 182         as3722_rtc = devm_kzalloc(&pdev->dev, sizeof(*as3722_rtc), GFP_KERNEL);
 183         if (!as3722_rtc)
 184                 return -ENOMEM;
 185
 186         as3722_rtc->as3722 = as3722;
 187         as3722_rtc->dev = &pdev->dev;
 188         platform_set_drvdata(pdev, as3722_rtc);
 189
 190         /* Enable the RTC to make sure it is running. */
 191         ret = as3722_update_bits(as3722, AS3722_RTC_CONTROL_REG,
 192                         AS3722_RTC_ON | AS3722_RTC_ALARM_WAKEUP_EN,
 193                         AS3722_RTC_ON | AS3722_RTC_ALARM_WAKEUP_EN);
 194         if (ret < 0) {
 195                 dev_err(&pdev->dev, "RTC_CONTROL reg write failed: %d\n", ret);
 196                 return ret;
 197         }
 198
 199         device_init_wakeup(&pdev->dev, 1);
 200
 201         as3722_rtc->rtc = devm_rtc_device_register(&pdev->dev, "as3722-rtc",
 202                                 &as3722_rtc_ops, THIS_MODULE);
 203         if (IS_ERR(as3722_rtc->rtc)) {
 204                 ret = PTR_ERR(as3722_rtc->rtc);
 205                 dev_err(&pdev->dev, "RTC register failed: %d\n", ret);
 206                 return ret;
 207         }
 208
 209         as3722_rtc->alarm_irq = platform_get_irq(pdev, 0);
 210         dev_info(&pdev->dev, "RTC interrupt %d\n", as3722_rtc->alarm_irq);
 211
 212         ret = devm_request_threaded_irq(&pdev->dev, as3722_rtc->alarm_irq, NULL,
 213                         as3722_alarm_irq, IRQF_ONESHOT | IRQF_EARLY_RESUME,
 214                         "rtc-alarm", as3722_rtc);
 215         if (ret < 0) {
 216                 dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n",
 217                                 as3722_rtc->alarm_irq, ret);
 218                 return ret;
 219         }
 220         disable_irq(as3722_rtc->alarm_irq);
 221         return 0;
 222 }
 223
 224 #ifdef CONFIG_PM_SLEEP
 225 static int as3722_rtc_suspend(struct device *dev)
 226 {
 227         struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
 228
 229         if (device_may_wakeup(dev))
 230                 enable_irq_wake(as3722_rtc->alarm_irq);
 231
 232         return 0;
 233 }
 234
 235 static int as3722_rtc_resume(struct device *dev)
 236 {
 237         struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
 238
 239         if (device_may_wakeup(dev))
 240                 disable_irq_wake(as3722_rtc->alarm_irq);
 241         return 0;
 242 }
 243 #endif
 244
 245 static SIMPLE_DEV_PM_OPS(as3722_rtc_pm_ops, as3722_rtc_suspend,
 246                          as3722_rtc_resume);
 247
 248 static struct platform_driver as3722_rtc_driver = {
 249         .probe = as3722_rtc_probe,
 250         .driver = {
 251                 .name = "as3722-rtc",
 252                 .pm = &as3722_rtc_pm_ops,
 253         },
 254 };
 255 module_platform_driver(as3722_rtc_driver);
 256
 257 MODULE_DESCRIPTION("RTC driver for AS3722 PMICs");
 258 MODULE_ALIAS("platform:as3722-rtc");
 259 MODULE_AUTHOR("Florian Lobmaier <florian.lobmaier@ams.com>");
 260 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
 261 MODULE_LICENSE("GPL");