drivers/rtc/rtc-rc5t583.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * rtc-rc5t583.c -- RICOH RC5T583 Real Time Clock
   4  *
   5  * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
   6  * Author: Venu Byravarasu <vbyravarasu@nvidia.com>
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/errno.h>
  11 #include <linux/init.h>
  12 #include <linux/module.h>
  13 #include <linux/types.h>
  14 #include <linux/rtc.h>
  15 #include <linux/bcd.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/mfd/rc5t583.h>
  19
  20 struct rc5t583_rtc {
  21         struct rtc_device       *rtc;
  22         /* To store the list of enabled interrupts, during system suspend */
  23         u32 irqen;
  24 };
  25
  26 /* Total number of RTC registers needed to set time*/
  27 #define NUM_TIME_REGS   (RC5T583_RTC_YEAR - RC5T583_RTC_SEC + 1)
  28
  29 /* Total number of RTC registers needed to set Y-Alarm*/
  30 #define NUM_YAL_REGS    (RC5T583_RTC_AY_YEAR - RC5T583_RTC_AY_MIN + 1)
  31
  32 /* Set Y-Alarm interrupt */
  33 #define SET_YAL BIT(5)
  34
  35 /* Get Y-Alarm interrupt status*/
  36 #define GET_YAL_STATUS BIT(3)
  37
  38 static int rc5t583_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
  39 {
  40         struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
  41         u8 val;
  42
  43         /* Set Y-Alarm, based on 'enabled' */
  44         val = enabled ? SET_YAL : 0;
  45
  46         return regmap_update_bits(rc5t583->regmap, RC5T583_RTC_CTL1, SET_YAL,
  47                 val);
  48 }
  49
  50 /*
  51  * Gets current rc5t583 RTC time and date parameters.
  52  *
  53  * The RTC's time/alarm representation is not what gmtime(3) requires
  54  * Linux to use:
  55  *
  56  *  - Months are 1..12 vs Linux 0-11
  57  *  - Years are 0..99 vs Linux 1900..N (we assume 21st century)
  58  */
  59 static int rc5t583_rtc_read_time(struct device *dev, struct rtc_time *tm)
  60 {
  61         struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
  62         u8 rtc_data[NUM_TIME_REGS];
  63         int ret;
  64
  65         ret = regmap_bulk_read(rc5t583->regmap, RC5T583_RTC_SEC, rtc_data,
  66                 NUM_TIME_REGS);
  67         if (ret < 0) {
  68                 dev_err(dev, "RTC read time failed with err:%d\n", ret);
  69                 return ret;
  70         }
  71
  72         tm->tm_sec = bcd2bin(rtc_data[0]);
  73         tm->tm_min = bcd2bin(rtc_data[1]);
  74         tm->tm_hour = bcd2bin(rtc_data[2]);
  75         tm->tm_wday = bcd2bin(rtc_data[3]);
  76         tm->tm_mday = bcd2bin(rtc_data[4]);
  77         tm->tm_mon = bcd2bin(rtc_data[5]) - 1;
  78         tm->tm_year = bcd2bin(rtc_data[6]) + 100;
  79
  80         return ret;
  81 }
  82
  83 static int rc5t583_rtc_set_time(struct device *dev, struct rtc_time *tm)
  84 {
  85         struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
  86         unsigned char rtc_data[NUM_TIME_REGS];
  87         int ret;
  88
  89         rtc_data[0] = bin2bcd(tm->tm_sec);
  90         rtc_data[1] = bin2bcd(tm->tm_min);
  91         rtc_data[2] = bin2bcd(tm->tm_hour);
  92         rtc_data[3] = bin2bcd(tm->tm_wday);
  93         rtc_data[4] = bin2bcd(tm->tm_mday);
  94         rtc_data[5] = bin2bcd(tm->tm_mon + 1);
  95         rtc_data[6] = bin2bcd(tm->tm_year - 100);
  96
  97         ret = regmap_bulk_write(rc5t583->regmap, RC5T583_RTC_SEC, rtc_data,
  98                 NUM_TIME_REGS);
  99         if (ret < 0) {
 100                 dev_err(dev, "RTC set time failed with error %d\n", ret);
 101                 return ret;
 102         }
 103
 104         return ret;
 105 }
 106
 107 static int rc5t583_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
 108 {
 109         struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
 110         unsigned char alarm_data[NUM_YAL_REGS];
 111         u32 interrupt_enable;
 112         int ret;
 113
 114         ret = regmap_bulk_read(rc5t583->regmap, RC5T583_RTC_AY_MIN, alarm_data,
 115                 NUM_YAL_REGS);
 116         if (ret < 0) {
 117                 dev_err(dev, "rtc_read_alarm error %d\n", ret);
 118                 return ret;
 119         }
 120
 121         alm->time.tm_sec = 0;
 122         alm->time.tm_min = bcd2bin(alarm_data[0]);
 123         alm->time.tm_hour = bcd2bin(alarm_data[1]);
 124         alm->time.tm_mday = bcd2bin(alarm_data[2]);
 125         alm->time.tm_mon = bcd2bin(alarm_data[3]) - 1;
 126         alm->time.tm_year = bcd2bin(alarm_data[4]) + 100;
 127
 128         ret = regmap_read(rc5t583->regmap, RC5T583_RTC_CTL1, &interrupt_enable);
 129         if (ret < 0)
 130                 return ret;
 131
 132         /* check if YALE is set */
 133         if (interrupt_enable & SET_YAL)
 134                 alm->enabled = 1;
 135
 136         return ret;
 137 }
 138
 139 static int rc5t583_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 140 {
 141         struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
 142         unsigned char alarm_data[NUM_YAL_REGS];
 143         int ret;
 144
 145         ret = rc5t583_rtc_alarm_irq_enable(dev, 0);
 146         if (ret)
 147                 return ret;
 148
 149         alarm_data[0] = bin2bcd(alm->time.tm_min);
 150         alarm_data[1] = bin2bcd(alm->time.tm_hour);
 151         alarm_data[2] = bin2bcd(alm->time.tm_mday);
 152         alarm_data[3] = bin2bcd(alm->time.tm_mon + 1);
 153         alarm_data[4] = bin2bcd(alm->time.tm_year - 100);
 154
 155         ret = regmap_bulk_write(rc5t583->regmap, RC5T583_RTC_AY_MIN, alarm_data,
 156                 NUM_YAL_REGS);
 157         if (ret) {
 158                 dev_err(dev, "rtc_set_alarm error %d\n", ret);
 159                 return ret;
 160         }
 161
 162         if (alm->enabled)
 163                 ret = rc5t583_rtc_alarm_irq_enable(dev, 1);
 164
 165         return ret;
 166 }
 167
 168 static irqreturn_t rc5t583_rtc_interrupt(int irq, void *rtc)
 169 {
 170         struct device *dev = rtc;
 171         struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
 172         struct rc5t583_rtc *rc5t583_rtc = dev_get_drvdata(dev);
 173         unsigned long events = 0;
 174         int ret;
 175         u32 rtc_reg;
 176
 177         ret = regmap_read(rc5t583->regmap, RC5T583_RTC_CTL2, &rtc_reg);
 178         if (ret < 0)
 179                 return IRQ_NONE;
 180
 181         if (rtc_reg & GET_YAL_STATUS) {
 182                 events = RTC_IRQF | RTC_AF;
 183                 /* clear pending Y-alarm interrupt bit */
 184                 rtc_reg &= ~GET_YAL_STATUS;
 185         }
 186
 187         ret = regmap_write(rc5t583->regmap, RC5T583_RTC_CTL2, rtc_reg);
 188         if (ret)
 189                 return IRQ_NONE;
 190
 191         /* Notify RTC core on event */
 192         rtc_update_irq(rc5t583_rtc->rtc, 1, events);
 193
 194         return IRQ_HANDLED;
 195 }
 196
 197 static const struct rtc_class_ops rc5t583_rtc_ops = {
 198         .read_time      = rc5t583_rtc_read_time,
 199         .set_time       = rc5t583_rtc_set_time,
 200         .read_alarm     = rc5t583_rtc_read_alarm,
 201         .set_alarm      = rc5t583_rtc_set_alarm,
 202         .alarm_irq_enable = rc5t583_rtc_alarm_irq_enable,
 203 };
 204
 205 static int rc5t583_rtc_probe(struct platform_device *pdev)
 206 {
 207         struct rc5t583 *rc5t583 = dev_get_drvdata(pdev->dev.parent);
 208         struct rc5t583_rtc *ricoh_rtc;
 209         struct rc5t583_platform_data *pmic_plat_data;
 210         int ret;
 211         int irq;
 212
 213         ricoh_rtc = devm_kzalloc(&pdev->dev, sizeof(struct rc5t583_rtc),
 214                         GFP_KERNEL);
 215         if (!ricoh_rtc)
 216                 return -ENOMEM;
 217
 218         platform_set_drvdata(pdev, ricoh_rtc);
 219
 220         /* Clear pending interrupts */
 221         ret = regmap_write(rc5t583->regmap, RC5T583_RTC_CTL2, 0);
 222         if (ret < 0)
 223                 return ret;
 224
 225         /* clear RTC Adjust register */
 226         ret = regmap_write(rc5t583->regmap, RC5T583_RTC_ADJ, 0);
 227         if (ret < 0) {
 228                 dev_err(&pdev->dev, "unable to program rtc_adjust reg\n");
 229                 return -EBUSY;
 230         }
 231
 232         pmic_plat_data = dev_get_platdata(rc5t583->dev);
 233         irq = pmic_plat_data->irq_base;
 234         if (irq <= 0) {
 235                 dev_warn(&pdev->dev, "Wake up is not possible as irq = %d\n",
 236                         irq);
 237                 return ret;
 238         }
 239
 240         irq += RC5T583_IRQ_YALE;
 241         ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
 242                 rc5t583_rtc_interrupt, IRQF_TRIGGER_LOW,
 243                 "rtc-rc5t583", &pdev->dev);
 244         if (ret < 0) {
 245                 dev_err(&pdev->dev, "IRQ is not free.\n");
 246                 return ret;
 247         }
 248         device_init_wakeup(&pdev->dev, 1);
 249
 250         ricoh_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
 251                 &rc5t583_rtc_ops, THIS_MODULE);
 252         if (IS_ERR(ricoh_rtc->rtc)) {
 253                 ret = PTR_ERR(ricoh_rtc->rtc);
 254                 dev_err(&pdev->dev, "RTC device register: err %d\n", ret);
 255                 return ret;
 256         }
 257
 258         return 0;
 259 }
 260
 261 /*
 262  * Disable rc5t583 RTC interrupts.
 263  * Sets status flag to free.
 264  */
 265 static int rc5t583_rtc_remove(struct platform_device *pdev)
 266 {
 267         struct rc5t583_rtc *rc5t583_rtc = platform_get_drvdata(pdev);
 268
 269         rc5t583_rtc_alarm_irq_enable(&rc5t583_rtc->rtc->dev, 0);
 270         return 0;
 271 }
 272
 273 #ifdef CONFIG_PM_SLEEP
 274 static int rc5t583_rtc_suspend(struct device *dev)
 275 {
 276         struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
 277         struct rc5t583_rtc *rc5t583_rtc = dev_get_drvdata(dev);
 278         int ret;
 279
 280         /* Store current list of enabled interrupts*/
 281         ret = regmap_read(rc5t583->regmap, RC5T583_RTC_CTL1,
 282                 &rc5t583_rtc->irqen);
 283         return ret;
 284 }
 285
 286 static int rc5t583_rtc_resume(struct device *dev)
 287 {
 288         struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
 289         struct rc5t583_rtc *rc5t583_rtc = dev_get_drvdata(dev);
 290
 291         /* Restore list of enabled interrupts before suspend */
 292         return regmap_write(rc5t583->regmap, RC5T583_RTC_CTL1,
 293                 rc5t583_rtc->irqen);
 294 }
 295 #endif
 296
 297 static SIMPLE_DEV_PM_OPS(rc5t583_rtc_pm_ops, rc5t583_rtc_suspend,
 298                         rc5t583_rtc_resume);
 299
 300 static struct platform_driver rc5t583_rtc_driver = {
 301         .probe          = rc5t583_rtc_probe,
 302         .remove         = rc5t583_rtc_remove,
 303         .driver         = {
 304                 .name   = "rtc-rc5t583",
 305                 .pm     = &rc5t583_rtc_pm_ops,
 306         },
 307 };
 308
 309 module_platform_driver(rc5t583_rtc_driver);
 310 MODULE_ALIAS("platform:rtc-rc5t583");
 311 MODULE_AUTHOR("Venu Byravarasu <vbyravarasu@nvidia.com>");
 312 MODULE_LICENSE("GPL v2");