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         /* To store the list of enabled interrupts */
  31         u32 irqstat;
  32 };
  33
  34 /* Total number of RTC registers needed to set time*/
  35 #define NUM_TIME_REGS   (TPS65910_YEARS - TPS65910_SECONDS + 1)
  36
  37 static int tps65910_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
  38 {
  39         struct tps65910 *tps = dev_get_drvdata(dev->parent);
  40         u8 val = 0;
  41
  42         if (enabled)
  43                 val = TPS65910_RTC_INTERRUPTS_IT_ALARM;
  44
  45         return regmap_write(tps->regmap, TPS65910_RTC_INTERRUPTS, val);
  46 }
  47
  48 /*
  49  * Gets current tps65910 RTC time and date parameters.
  50  *
  51  * The RTC's time/alarm representation is not what gmtime(3) requires
  52  * Linux to use:
  53  *
  54  *  - Months are 1..12 vs Linux 0-11
  55  *  - Years are 0..99 vs Linux 1900..N (we assume 21st century)
  56  */
  57 static int tps65910_rtc_read_time(struct device *dev, struct rtc_time *tm)
  58 {
  59         unsigned char rtc_data[NUM_TIME_REGS];
  60         struct tps65910 *tps = dev_get_drvdata(dev->parent);
  61         int ret;
  62
  63         /* Copy RTC counting registers to static registers or latches */
  64         ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
  65                 TPS65910_RTC_CTRL_GET_TIME, TPS65910_RTC_CTRL_GET_TIME);
  66         if (ret < 0) {
  67                 dev_err(dev, "RTC CTRL reg update failed with err:%d\n", ret);
  68                 return ret;
  69         }
  70
  71         ret = regmap_bulk_read(tps->regmap, TPS65910_SECONDS, rtc_data,
  72                 NUM_TIME_REGS);
  73         if (ret < 0) {
  74                 dev_err(dev, "reading from RTC failed with err:%d\n", ret);
  75                 return ret;
  76         }
  77
  78         tm->tm_sec = bcd2bin(rtc_data[0]);
  79         tm->tm_min = bcd2bin(rtc_data[1]);
  80         tm->tm_hour = bcd2bin(rtc_data[2]);
  81         tm->tm_mday = bcd2bin(rtc_data[3]);
  82         tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
  83         tm->tm_year = bcd2bin(rtc_data[5]) + 100;
  84
  85         return ret;
  86 }
  87
  88 static int tps65910_rtc_set_time(struct device *dev, struct rtc_time *tm)
  89 {
  90         unsigned char rtc_data[NUM_TIME_REGS];
  91         struct tps65910 *tps = dev_get_drvdata(dev->parent);
  92         int ret;
  93
  94         rtc_data[0] = bin2bcd(tm->tm_sec);
  95         rtc_data[1] = bin2bcd(tm->tm_min);
  96         rtc_data[2] = bin2bcd(tm->tm_hour);
  97         rtc_data[3] = bin2bcd(tm->tm_mday);
  98         rtc_data[4] = bin2bcd(tm->tm_mon + 1);
  99         rtc_data[5] = bin2bcd(tm->tm_year - 100);
 100
 101         /* Stop RTC while updating the RTC time registers */
 102         ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
 103                 TPS65910_RTC_CTRL_STOP_RTC, 0);
 104         if (ret < 0) {
 105                 dev_err(dev, "RTC stop failed with err:%d\n", ret);
 106                 return ret;
 107         }
 108
 109         /* update all the time registers in one shot */
 110         ret = regmap_bulk_write(tps->regmap, TPS65910_SECONDS, rtc_data,
 111                 NUM_TIME_REGS);
 112         if (ret < 0) {
 113                 dev_err(dev, "rtc_set_time error %d\n", ret);
 114                 return ret;
 115         }
 116
 117         /* Start back RTC */
 118         ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
 119                 TPS65910_RTC_CTRL_STOP_RTC, 1);
 120         if (ret < 0)
 121                 dev_err(dev, "RTC start failed with err:%d\n", ret);
 122
 123         return ret;
 124 }
 125
 126 /*
 127  * Gets current tps65910 RTC alarm time.
 128  */
 129 static int tps65910_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
 130 {
 131         unsigned char alarm_data[NUM_TIME_REGS];
 132         u32 int_val;
 133         struct tps65910 *tps = dev_get_drvdata(dev->parent);
 134         int ret;
 135
 136         ret = regmap_bulk_read(tps->regmap, TPS65910_SECONDS, alarm_data,
 137                 NUM_TIME_REGS);
 138         if (ret < 0) {
 139                 dev_err(dev, "rtc_read_alarm error %d\n", ret);
 140                 return ret;
 141         }
 142
 143         alm->time.tm_sec = bcd2bin(alarm_data[0]);
 144         alm->time.tm_min = bcd2bin(alarm_data[1]);
 145         alm->time.tm_hour = bcd2bin(alarm_data[2]);
 146         alm->time.tm_mday = bcd2bin(alarm_data[3]);
 147         alm->time.tm_mon = bcd2bin(alarm_data[4]) - 1;
 148         alm->time.tm_year = bcd2bin(alarm_data[5]) + 100;
 149
 150         ret = regmap_read(tps->regmap, TPS65910_RTC_INTERRUPTS, &int_val);
 151         if (ret < 0)
 152                 return ret;
 153
 154         if (int_val & TPS65910_RTC_INTERRUPTS_IT_ALARM)
 155                 alm->enabled = 1;
 156
 157         return ret;
 158 }
 159
 160 static int tps65910_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 161 {
 162         unsigned char alarm_data[NUM_TIME_REGS];
 163         struct tps65910 *tps = dev_get_drvdata(dev->parent);
 164         int ret;
 165
 166         ret = tps65910_rtc_alarm_irq_enable(dev, 0);
 167         if (ret)
 168                 return ret;
 169
 170         alarm_data[0] = bin2bcd(alm->time.tm_sec);
 171         alarm_data[1] = bin2bcd(alm->time.tm_min);
 172         alarm_data[2] = bin2bcd(alm->time.tm_hour);
 173         alarm_data[3] = bin2bcd(alm->time.tm_mday);
 174         alarm_data[4] = bin2bcd(alm->time.tm_mon + 1);
 175         alarm_data[5] = bin2bcd(alm->time.tm_year - 100);
 176
 177         /* update all the alarm registers in one shot */
 178         ret = regmap_bulk_write(tps->regmap, TPS65910_ALARM_SECONDS,
 179                 alarm_data, NUM_TIME_REGS);
 180         if (ret) {
 181                 dev_err(dev, "rtc_set_alarm error %d\n", ret);
 182                 return ret;
 183         }
 184
 185         if (alm->enabled)
 186                 ret = tps65910_rtc_alarm_irq_enable(dev, 1);
 187
 188         return ret;
 189 }
 190
 191 static irqreturn_t tps65910_rtc_interrupt(int irq, void *rtc)
 192 {
 193         struct device *dev = rtc;
 194         unsigned long events = 0;
 195         struct tps65910 *tps = dev_get_drvdata(dev->parent);
 196         struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
 197         int ret;
 198         u32 rtc_reg;
 199
 200         ret = regmap_read(tps->regmap, TPS65910_RTC_STATUS, &rtc_reg);
 201         if (ret)
 202                 return IRQ_NONE;
 203
 204         if (rtc_reg & TPS65910_RTC_STATUS_ALARM)
 205                 events = RTC_IRQF | RTC_AF;
 206
 207         ret = regmap_write(tps->regmap, TPS65910_RTC_STATUS, rtc_reg);
 208         if (ret)
 209                 return IRQ_NONE;
 210
 211         /* Notify RTC core on event */
 212         rtc_update_irq(tps_rtc->rtc, 1, events);
 213
 214         return IRQ_HANDLED;
 215 }
 216
 217 static const struct rtc_class_ops tps65910_rtc_ops = {
 218         .read_time      = tps65910_rtc_read_time,
 219         .set_time       = tps65910_rtc_set_time,
 220         .read_alarm     = tps65910_rtc_read_alarm,
 221         .set_alarm      = tps65910_rtc_set_alarm,
 222         .alarm_irq_enable = tps65910_rtc_alarm_irq_enable,
 223 };
 224
 225 static int tps65910_rtc_probe(struct platform_device *pdev)
 226 {
 227         struct tps65910 *tps65910 = NULL;
 228         struct tps65910_rtc *tps_rtc = NULL;
 229         int ret;
 230         int irq;
 231         u32 rtc_reg;
 232
 233         tps65910 = dev_get_drvdata(pdev->dev.parent);
 234
 235         tps_rtc = devm_kzalloc(&pdev->dev, sizeof(struct tps65910_rtc),
 236                         GFP_KERNEL);
 237         if (!tps_rtc)
 238                 return -ENOMEM;
 239
 240         /* Clear pending interrupts */
 241         ret = regmap_read(tps65910->regmap, TPS65910_RTC_STATUS, &rtc_reg);
 242         if (ret < 0)
 243                 return ret;
 244
 245         ret = regmap_write(tps65910->regmap, TPS65910_RTC_STATUS, rtc_reg);
 246         if (ret < 0)
 247                 return ret;
 248
 249         dev_dbg(&pdev->dev, "Enabling rtc-tps65910.\n");
 250
 251         /* Enable RTC digital power domain */
 252         ret = regmap_update_bits(tps65910->regmap, TPS65910_DEVCTRL,
 253                 DEVCTRL_RTC_PWDN_MASK, 0 << DEVCTRL_RTC_PWDN_SHIFT);
 254         if (ret < 0)
 255                 return ret;
 256
 257         rtc_reg = TPS65910_RTC_CTRL_STOP_RTC;
 258         ret = regmap_write(tps65910->regmap, TPS65910_RTC_CTRL, rtc_reg);
 259         if (ret < 0)
 260                 return ret;
 261
 262         irq  = platform_get_irq(pdev, 0);
 263         if (irq <= 0) {
 264                 dev_warn(&pdev->dev, "Wake up is not possible as irq = %d\n",
 265                         irq);
 266                 return ret;
 267         }
 268
 269         ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
 270                 tps65910_rtc_interrupt, IRQF_TRIGGER_LOW,
 271                 dev_name(&pdev->dev), &pdev->dev);
 272         if (ret < 0) {
 273                 dev_err(&pdev->dev, "IRQ is not free.\n");
 274                 return ret;
 275         }
 276         device_init_wakeup(&pdev->dev, 1);
 277
 278         tps_rtc->rtc = rtc_device_register(pdev->name, &pdev->dev,
 279                 &tps65910_rtc_ops, THIS_MODULE);
 280         if (IS_ERR(tps_rtc->rtc)) {
 281                 ret = PTR_ERR(tps_rtc->rtc);
 282                 dev_err(&pdev->dev, "RTC device register: err %d\n", ret);
 283                 return ret;
 284         }
 285
 286         platform_set_drvdata(pdev, tps_rtc);
 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         /* leave rtc running, but disable irqs */
 298         struct tps65910_rtc *tps_rtc = platform_get_drvdata(pdev);
 299
 300         tps65910_rtc_alarm_irq_enable(&pdev->dev, 0);
 301
 302         rtc_device_unregister(tps_rtc->rtc);
 303         return 0;
 304 }
 305
 306 #ifdef CONFIG_PM_SLEEP
 307
 308 static int tps65910_rtc_suspend(struct device *dev)
 309 {
 310         struct tps65910 *tps = dev_get_drvdata(dev->parent);
 311         u8 alarm = TPS65910_RTC_INTERRUPTS_IT_ALARM;
 312         int ret;
 313
 314         /* Store current list of enabled interrupts*/
 315         ret = regmap_read(tps->regmap, TPS65910_RTC_INTERRUPTS,
 316                 &tps->rtc->irqstat);
 317         if (ret < 0)
 318                 return ret;
 319
 320         /* Enable RTC ALARM interrupt only */
 321         return regmap_write(tps->regmap, TPS65910_RTC_INTERRUPTS, alarm);
 322 }
 323
 324 static int tps65910_rtc_resume(struct device *dev)
 325 {
 326         struct tps65910 *tps = dev_get_drvdata(dev->parent);
 327
 328         /* Restore list of enabled interrupts before suspend */
 329         return regmap_write(tps->regmap, TPS65910_RTC_INTERRUPTS,
 330                 tps->rtc->irqstat);
 331 }
 332
 333 static const struct dev_pm_ops tps65910_rtc_pm_ops = {
 334         .suspend        = tps65910_rtc_suspend,
 335         .resume         = tps65910_rtc_resume,
 336 };
 337
 338 #define DEV_PM_OPS     (&tps65910_rtc_pm_ops)
 339 #else
 340 #define DEV_PM_OPS     NULL
 341 #endif
 342
 343 static struct platform_driver tps65910_rtc_driver = {
 344         .probe          = tps65910_rtc_probe,
 345         .remove         = tps65910_rtc_remove,
 346         .driver         = {
 347                 .owner  = THIS_MODULE,
 348                 .name   = "tps65910-rtc",
 349                 .pm     = DEV_PM_OPS,
 350         },
 351 };
 352
 353 module_platform_driver(tps65910_rtc_driver);
 354 MODULE_ALIAS("platform:rtc-tps65910");
 355 MODULE_AUTHOR("Venu Byravarasu <vbyravarasu@nvidia.com>");
 356 MODULE_LICENSE("GPL");