drivers/rtc/rtc-tps65910.c

   1 /*
   2  * rtc-tps65910.c -- TPS65910 Real Time Clock interface
   3  *
   4  * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
   5  * Author: Venu Byravarasu <vbyravarasu@nvidia.com>
   6  *
   7  * Based on original TI driver rtc-twl.c
   8  *   Copyright (C) 2007 MontaVista Software, Inc
   9  *   Author: Alexandre Rusev <source@mvista.com>
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version
  14  * 2 of the License, or (at your option) any later version.
  15  */
  16
  17 #include <linux/kernel.h>
  18 #include <linux/errno.h>
  19 #include <linux/init.h>
  20 #include <linux/module.h>
  21 #include <linux/types.h>
  22 #include <linux/rtc.h>
  23 #include <linux/bcd.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/interrupt.h>
  26 #include <linux/mfd/tps65910.h>
  27
  28 struct tps65910_rtc {
  29         struct rtc_device       *rtc;
  30         int irq;
  31 };
  32
  33 /* Total number of RTC registers needed to set time*/
  34 #define NUM_TIME_REGS   (TPS65910_YEARS - TPS65910_SECONDS + 1)
  35
  36 static int tps65910_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
  37 {
  38         struct tps65910 *tps = dev_get_drvdata(dev->parent);
  39         u8 val = 0;
  40
  41         if (enabled)
  42                 val = TPS65910_RTC_INTERRUPTS_IT_ALARM;
  43
  44         return regmap_write(tps->regmap, TPS65910_RTC_INTERRUPTS, val);
  45 }
  46
  47 /*
  48  * Gets current tps65910 RTC time and date parameters.
  49  *
  50  * The RTC's time/alarm representation is not what gmtime(3) requires
  51  * Linux to use:
  52  *
  53  *  - Months are 1..12 vs Linux 0-11
  54  *  - Years are 0..99 vs Linux 1900..N (we assume 21st century)
  55  */
  56 static int tps65910_rtc_read_time(struct device *dev, struct rtc_time *tm)
  57 {
  58         unsigned char rtc_data[NUM_TIME_REGS];
  59         struct tps65910 *tps = dev_get_drvdata(dev->parent);
  60         int ret;
  61
  62         /* Copy RTC counting registers to static registers or latches */
  63         ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
  64                 TPS65910_RTC_CTRL_GET_TIME, TPS65910_RTC_CTRL_GET_TIME);
  65         if (ret < 0) {
  66                 dev_err(dev, "RTC CTRL reg update failed with err:%d\n", ret);
  67                 return ret;
  68         }
  69
  70         ret = regmap_bulk_read(tps->regmap, TPS65910_SECONDS, rtc_data,
  71                 NUM_TIME_REGS);
  72         if (ret < 0) {
  73                 dev_err(dev, "reading from RTC failed with err:%d\n", ret);
  74                 return ret;
  75         }
  76
  77         tm->tm_sec = bcd2bin(rtc_data[0]);
  78         tm->tm_min = bcd2bin(rtc_data[1]);
  79         tm->tm_hour = bcd2bin(rtc_data[2]);
  80         tm->tm_mday = bcd2bin(rtc_data[3]);
  81         tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
  82         tm->tm_year = bcd2bin(rtc_data[5]) + 100;
  83
  84         return ret;
  85 }
  86
  87 static int tps65910_rtc_set_time(struct device *dev, struct rtc_time *tm)
  88 {
  89         unsigned char rtc_data[NUM_TIME_REGS];
  90         struct tps65910 *tps = dev_get_drvdata(dev->parent);
  91         int ret;
  92
  93         rtc_data[0] = bin2bcd(tm->tm_sec);
  94         rtc_data[1] = bin2bcd(tm->tm_min);
  95         rtc_data[2] = bin2bcd(tm->tm_hour);
  96         rtc_data[3] = bin2bcd(tm->tm_mday);
  97         rtc_data[4] = bin2bcd(tm->tm_mon + 1);
  98         rtc_data[5] = bin2bcd(tm->tm_year - 100);
  99
 100         /* Stop RTC while updating the RTC time registers */
 101         ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
 102                 TPS65910_RTC_CTRL_STOP_RTC, 0);
 103         if (ret < 0) {
 104                 dev_err(dev, "RTC stop failed with err:%d\n", ret);
 105                 return ret;
 106         }
 107
 108         /* update all the time registers in one shot */
 109         ret = regmap_bulk_write(tps->regmap, TPS65910_SECONDS, rtc_data,
 110                 NUM_TIME_REGS);
 111         if (ret < 0) {
 112                 dev_err(dev, "rtc_set_time error %d\n", ret);
 113                 return ret;
 114         }
 115
 116         /* Start back RTC */
 117         ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
 118                 TPS65910_RTC_CTRL_STOP_RTC, 1);
 119         if (ret < 0)
 120                 dev_err(dev, "RTC start failed with err:%d\n", ret);
 121
 122         return ret;
 123 }
 124
 125 /*
 126  * Gets current tps65910 RTC alarm time.
 127  */
 128 static int tps65910_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
 129 {
 130         unsigned char alarm_data[NUM_TIME_REGS];
 131         u32 int_val;
 132         struct tps65910 *tps = dev_get_drvdata(dev->parent);
 133         int ret;
 134
 135         ret = regmap_bulk_read(tps->regmap, TPS65910_SECONDS, alarm_data,
 136                 NUM_TIME_REGS);
 137         if (ret < 0) {
 138                 dev_err(dev, "rtc_read_alarm error %d\n", ret);
 139                 return ret;
 140         }
 141
 142         alm->time.tm_sec = bcd2bin(alarm_data[0]);
 143         alm->time.tm_min = bcd2bin(alarm_data[1]);
 144         alm->time.tm_hour = bcd2bin(alarm_data[2]);
 145         alm->time.tm_mday = bcd2bin(alarm_data[3]);
 146         alm->time.tm_mon = bcd2bin(alarm_data[4]) - 1;
 147         alm->time.tm_year = bcd2bin(alarm_data[5]) + 100;
 148
 149         ret = regmap_read(tps->regmap, TPS65910_RTC_INTERRUPTS, &int_val);
 150         if (ret < 0)
 151                 return ret;
 152
 153         if (int_val & TPS65910_RTC_INTERRUPTS_IT_ALARM)
 154                 alm->enabled = 1;
 155
 156         return ret;
 157 }
 158
 159 static int tps65910_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 160 {
 161         unsigned char alarm_data[NUM_TIME_REGS];
 162         struct tps65910 *tps = dev_get_drvdata(dev->parent);
 163         int ret;
 164
 165         ret = tps65910_rtc_alarm_irq_enable(dev, 0);
 166         if (ret)
 167                 return ret;
 168
 169         alarm_data[0] = bin2bcd(alm->time.tm_sec);
 170         alarm_data[1] = bin2bcd(alm->time.tm_min);
 171         alarm_data[2] = bin2bcd(alm->time.tm_hour);
 172         alarm_data[3] = bin2bcd(alm->time.tm_mday);
 173         alarm_data[4] = bin2bcd(alm->time.tm_mon + 1);
 174         alarm_data[5] = bin2bcd(alm->time.tm_year - 100);
 175
 176         /* update all the alarm registers in one shot */
 177         ret = regmap_bulk_write(tps->regmap, TPS65910_ALARM_SECONDS,
 178                 alarm_data, NUM_TIME_REGS);
 179         if (ret) {
 180                 dev_err(dev, "rtc_set_alarm error %d\n", ret);
 181                 return ret;
 182         }
 183
 184         if (alm->enabled)
 185                 ret = tps65910_rtc_alarm_irq_enable(dev, 1);
 186
 187         return ret;
 188 }
 189
 190 static irqreturn_t tps65910_rtc_interrupt(int irq, void *rtc)
 191 {
 192         struct device *dev = rtc;
 193         unsigned long events = 0;
 194         struct tps65910 *tps = dev_get_drvdata(dev->parent);
 195         struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
 196         int ret;
 197         u32 rtc_reg;
 198
 199         ret = regmap_read(tps->regmap, TPS65910_RTC_STATUS, &rtc_reg);
 200         if (ret)
 201                 return IRQ_NONE;
 202
 203         if (rtc_reg & TPS65910_RTC_STATUS_ALARM)
 204                 events = RTC_IRQF | RTC_AF;
 205
 206         ret = regmap_write(tps->regmap, TPS65910_RTC_STATUS, rtc_reg);
 207         if (ret)
 208                 return IRQ_NONE;
 209
 210         /* Notify RTC core on event */
 211         rtc_update_irq(tps_rtc->rtc, 1, events);
 212
 213         return IRQ_HANDLED;
 214 }
 215
 216 static const struct rtc_class_ops tps65910_rtc_ops = {
 217         .read_time      = tps65910_rtc_read_time,
 218         .set_time       = tps65910_rtc_set_time,
 219         .read_alarm     = tps65910_rtc_read_alarm,
 220         .set_alarm      = tps65910_rtc_set_alarm,
 221         .alarm_irq_enable = tps65910_rtc_alarm_irq_enable,
 222 };
 223
 224 static int tps65910_rtc_probe(struct platform_device *pdev)
 225 {
 226         struct tps65910 *tps65910 = NULL;
 227         struct tps65910_rtc *tps_rtc = NULL;
 228         int ret;
 229         int irq;
 230         u32 rtc_reg;
 231
 232         tps65910 = dev_get_drvdata(pdev->dev.parent);
 233
 234         tps_rtc = devm_kzalloc(&pdev->dev, sizeof(struct tps65910_rtc),
 235                         GFP_KERNEL);
 236         if (!tps_rtc)
 237                 return -ENOMEM;
 238
 239         /* Clear pending interrupts */
 240         ret = regmap_read(tps65910->regmap, TPS65910_RTC_STATUS, &rtc_reg);
 241         if (ret < 0)
 242                 return ret;
 243
 244         ret = regmap_write(tps65910->regmap, TPS65910_RTC_STATUS, rtc_reg);
 245         if (ret < 0)
 246                 return ret;
 247
 248         dev_dbg(&pdev->dev, "Enabling rtc-tps65910.\n");
 249
 250         /* Enable RTC digital power domain */
 251         ret = regmap_update_bits(tps65910->regmap, TPS65910_DEVCTRL,
 252                 DEVCTRL_RTC_PWDN_MASK, 0 << DEVCTRL_RTC_PWDN_SHIFT);
 253         if (ret < 0)
 254                 return ret;
 255
 256         rtc_reg = TPS65910_RTC_CTRL_STOP_RTC;
 257         ret = regmap_write(tps65910->regmap, TPS65910_RTC_CTRL, rtc_reg);
 258         if (ret < 0)
 259                 return ret;
 260
 261         platform_set_drvdata(pdev, tps_rtc);
 262
 263         irq  = platform_get_irq(pdev, 0);
 264         if (irq <= 0) {
 265                 dev_warn(&pdev->dev, "Wake up is not possible as irq = %d\n",
 266                         irq);
 267                 return -ENXIO;
 268         }
 269
 270         ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
 271                 tps65910_rtc_interrupt, IRQF_TRIGGER_LOW | IRQF_EARLY_RESUME,
 272                 dev_name(&pdev->dev), &pdev->dev);
 273         if (ret < 0) {
 274                 dev_err(&pdev->dev, "IRQ is not free.\n");
 275                 return ret;
 276         }
 277         tps_rtc->irq = irq;
 278         device_set_wakeup_capable(&pdev->dev, 1);
 279
 280         tps_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
 281                 &tps65910_rtc_ops, THIS_MODULE);
 282         if (IS_ERR(tps_rtc->rtc)) {
 283                 ret = PTR_ERR(tps_rtc->rtc);
 284                 dev_err(&pdev->dev, "RTC device register: err %d\n", ret);
 285                 return ret;
 286         }
 287
 288         return 0;
 289 }
 290
 291 /*
 292  * Disable tps65910 RTC interrupts.
 293  * Sets status flag to free.
 294  */
 295 static int tps65910_rtc_remove(struct platform_device *pdev)
 296 {
 297         tps65910_rtc_alarm_irq_enable(&pdev->dev, 0);
 298
 299         return 0;
 300 }
 301
 302 #ifdef CONFIG_PM_SLEEP
 303 static int tps65910_rtc_suspend(struct device *dev)
 304 {
 305         struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
 306
 307         if (device_may_wakeup(dev))
 308                 enable_irq_wake(tps_rtc->irq);
 309         return 0;
 310 }
 311
 312 static int tps65910_rtc_resume(struct device *dev)
 313 {
 314         struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
 315
 316         if (device_may_wakeup(dev))
 317                 disable_irq_wake(tps_rtc->irq);
 318         return 0;
 319 }
 320 #endif
 321
 322 static SIMPLE_DEV_PM_OPS(tps65910_rtc_pm_ops, tps65910_rtc_suspend,
 323                         tps65910_rtc_resume);
 324
 325 static struct platform_driver tps65910_rtc_driver = {
 326         .probe          = tps65910_rtc_probe,
 327         .remove         = tps65910_rtc_remove,
 328         .driver         = {
 329                 .name   = "tps65910-rtc",
 330                 .pm     = &tps65910_rtc_pm_ops,
 331         },
 332 };
 333
 334 module_platform_driver(tps65910_rtc_driver);
 335 MODULE_ALIAS("platform:rtc-tps65910");
 336 MODULE_AUTHOR("Venu Byravarasu <vbyravarasu@nvidia.com>");
 337 MODULE_LICENSE("GPL");