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         /* To store the list of enabled interrupts */
  32         u32 irqstat;
  33 };
  34
  35 /* Total number of RTC registers needed to set time*/
  36 #define NUM_TIME_REGS   (TPS65910_YEARS - TPS65910_SECONDS + 1)
  37
  38 static int tps65910_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
  39 {
  40         struct tps65910 *tps = dev_get_drvdata(dev->parent);
  41         u8 val = 0;
  42
  43         if (enabled)
  44                 val = TPS65910_RTC_INTERRUPTS_IT_ALARM;
  45
  46         return regmap_write(tps->regmap, TPS65910_RTC_INTERRUPTS, val);
  47 }
  48
  49 /*
  50  * Gets current tps65910 RTC time and date parameters.
  51  *
  52  * The RTC's time/alarm representation is not what gmtime(3) requires
  53  * Linux to use:
  54  *
  55  *  - Months are 1..12 vs Linux 0-11
  56  *  - Years are 0..99 vs Linux 1900..N (we assume 21st century)
  57  */
  58 static int tps65910_rtc_read_time(struct device *dev, struct rtc_time *tm)
  59 {
  60         unsigned char rtc_data[NUM_TIME_REGS];
  61         struct tps65910 *tps = dev_get_drvdata(dev->parent);
  62         int ret;
  63
  64         /* Copy RTC counting registers to static registers or latches */
  65         ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
  66                 TPS65910_RTC_CTRL_GET_TIME, TPS65910_RTC_CTRL_GET_TIME);
  67         if (ret < 0) {
  68                 dev_err(dev, "RTC CTRL reg update failed with err:%d\n", ret);
  69                 return ret;
  70         }
  71
  72         ret = regmap_bulk_read(tps->regmap, TPS65910_SECONDS, rtc_data,
  73                 NUM_TIME_REGS);
  74         if (ret < 0) {
  75                 dev_err(dev, "reading from RTC failed with err:%d\n", ret);
  76                 return ret;
  77         }
  78
  79         tm->tm_sec = bcd2bin(rtc_data[0]);
  80         tm->tm_min = bcd2bin(rtc_data[1]);
  81         tm->tm_hour = bcd2bin(rtc_data[2]);
  82         tm->tm_mday = bcd2bin(rtc_data[3]);
  83         tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
  84         tm->tm_year = bcd2bin(rtc_data[5]) + 100;
  85
  86         return ret;
  87 }
  88
  89 static int tps65910_rtc_set_time(struct device *dev, struct rtc_time *tm)
  90 {
  91         unsigned char rtc_data[NUM_TIME_REGS];
  92         struct tps65910 *tps = dev_get_drvdata(dev->parent);
  93         int ret;
  94
  95         rtc_data[0] = bin2bcd(tm->tm_sec);
  96         rtc_data[1] = bin2bcd(tm->tm_min);
  97         rtc_data[2] = bin2bcd(tm->tm_hour);
  98         rtc_data[3] = bin2bcd(tm->tm_mday);
  99         rtc_data[4] = bin2bcd(tm->tm_mon + 1);
 100         rtc_data[5] = bin2bcd(tm->tm_year - 100);
 101
 102         /* Stop RTC while updating the RTC time registers */
 103         ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
 104                 TPS65910_RTC_CTRL_STOP_RTC, 0);
 105         if (ret < 0) {
 106                 dev_err(dev, "RTC stop failed with err:%d\n", ret);
 107                 return ret;
 108         }
 109
 110         /* update all the time registers in one shot */
 111         ret = regmap_bulk_write(tps->regmap, TPS65910_SECONDS, rtc_data,
 112                 NUM_TIME_REGS);
 113         if (ret < 0) {
 114                 dev_err(dev, "rtc_set_time error %d\n", ret);
 115                 return ret;
 116         }
 117
 118         /* Start back RTC */
 119         ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
 120                 TPS65910_RTC_CTRL_STOP_RTC, 1);
 121         if (ret < 0)
 122                 dev_err(dev, "RTC start failed with err:%d\n", ret);
 123
 124         return ret;
 125 }
 126
 127 /*
 128  * Gets current tps65910 RTC alarm time.
 129  */
 130 static int tps65910_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
 131 {
 132         unsigned char alarm_data[NUM_TIME_REGS];
 133         u32 int_val;
 134         struct tps65910 *tps = dev_get_drvdata(dev->parent);
 135         int ret;
 136
 137         ret = regmap_bulk_read(tps->regmap, TPS65910_SECONDS, alarm_data,
 138                 NUM_TIME_REGS);
 139         if (ret < 0) {
 140                 dev_err(dev, "rtc_read_alarm error %d\n", ret);
 141                 return ret;
 142         }
 143
 144         alm->time.tm_sec = bcd2bin(alarm_data[0]);
 145         alm->time.tm_min = bcd2bin(alarm_data[1]);
 146         alm->time.tm_hour = bcd2bin(alarm_data[2]);
 147         alm->time.tm_mday = bcd2bin(alarm_data[3]);
 148         alm->time.tm_mon = bcd2bin(alarm_data[4]) - 1;
 149         alm->time.tm_year = bcd2bin(alarm_data[5]) + 100;
 150
 151         ret = regmap_read(tps->regmap, TPS65910_RTC_INTERRUPTS, &int_val);
 152         if (ret < 0)
 153                 return ret;
 154
 155         if (int_val & TPS65910_RTC_INTERRUPTS_IT_ALARM)
 156                 alm->enabled = 1;
 157
 158         return ret;
 159 }
 160
 161 static int tps65910_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 162 {
 163         unsigned char alarm_data[NUM_TIME_REGS];
 164         struct tps65910 *tps = dev_get_drvdata(dev->parent);
 165         int ret;
 166
 167         ret = tps65910_rtc_alarm_irq_enable(dev, 0);
 168         if (ret)
 169                 return ret;
 170
 171         alarm_data[0] = bin2bcd(alm->time.tm_sec);
 172         alarm_data[1] = bin2bcd(alm->time.tm_min);
 173         alarm_data[2] = bin2bcd(alm->time.tm_hour);
 174         alarm_data[3] = bin2bcd(alm->time.tm_mday);
 175         alarm_data[4] = bin2bcd(alm->time.tm_mon + 1);
 176         alarm_data[5] = bin2bcd(alm->time.tm_year - 100);
 177
 178         /* update all the alarm registers in one shot */
 179         ret = regmap_bulk_write(tps->regmap, TPS65910_ALARM_SECONDS,
 180                 alarm_data, NUM_TIME_REGS);
 181         if (ret) {
 182                 dev_err(dev, "rtc_set_alarm error %d\n", ret);
 183                 return ret;
 184         }
 185
 186         if (alm->enabled)
 187                 ret = tps65910_rtc_alarm_irq_enable(dev, 1);
 188
 189         return ret;
 190 }
 191
 192 static irqreturn_t tps65910_rtc_interrupt(int irq, void *rtc)
 193 {
 194         struct device *dev = rtc;
 195         unsigned long events = 0;
 196         struct tps65910 *tps = dev_get_drvdata(dev->parent);
 197         struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
 198         int ret;
 199         u32 rtc_reg;
 200
 201         ret = regmap_read(tps->regmap, TPS65910_RTC_STATUS, &rtc_reg);
 202         if (ret)
 203                 return IRQ_NONE;
 204
 205         if (rtc_reg & TPS65910_RTC_STATUS_ALARM)
 206                 events = RTC_IRQF | RTC_AF;
 207
 208         ret = regmap_write(tps->regmap, TPS65910_RTC_STATUS, rtc_reg);
 209         if (ret)
 210                 return IRQ_NONE;
 211
 212         /* Notify RTC core on event */
 213         rtc_update_irq(tps_rtc->rtc, 1, events);
 214
 215         return IRQ_HANDLED;
 216 }
 217
 218 static const struct rtc_class_ops tps65910_rtc_ops = {
 219         .read_time      = tps65910_rtc_read_time,
 220         .set_time       = tps65910_rtc_set_time,
 221         .read_alarm     = tps65910_rtc_read_alarm,
 222         .set_alarm      = tps65910_rtc_set_alarm,
 223         .alarm_irq_enable = tps65910_rtc_alarm_irq_enable,
 224 };
 225
 226 static int tps65910_rtc_probe(struct platform_device *pdev)
 227 {
 228         struct tps65910 *tps65910 = NULL;
 229         struct tps65910_rtc *tps_rtc = NULL;
 230         int ret;
 231         int irq;
 232         u32 rtc_reg;
 233
 234         tps65910 = dev_get_drvdata(pdev->dev.parent);
 235
 236         tps_rtc = devm_kzalloc(&pdev->dev, sizeof(struct tps65910_rtc),
 237                         GFP_KERNEL);
 238         if (!tps_rtc)
 239                 return -ENOMEM;
 240
 241         /* Clear pending interrupts */
 242         ret = regmap_read(tps65910->regmap, TPS65910_RTC_STATUS, &rtc_reg);
 243         if (ret < 0)
 244                 return ret;
 245
 246         ret = regmap_write(tps65910->regmap, TPS65910_RTC_STATUS, rtc_reg);
 247         if (ret < 0)
 248                 return ret;
 249
 250         dev_dbg(&pdev->dev, "Enabling rtc-tps65910.\n");
 251
 252         /* Enable RTC digital power domain */
 253         ret = regmap_update_bits(tps65910->regmap, TPS65910_DEVCTRL,
 254                 DEVCTRL_RTC_PWDN_MASK, 0 << DEVCTRL_RTC_PWDN_SHIFT);
 255         if (ret < 0)
 256                 return ret;
 257
 258         rtc_reg = TPS65910_RTC_CTRL_STOP_RTC;
 259         ret = regmap_write(tps65910->regmap, TPS65910_RTC_CTRL, rtc_reg);
 260         if (ret < 0)
 261                 return ret;
 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 ret;
 268         }
 269
 270         ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
 271                 tps65910_rtc_interrupt, IRQF_TRIGGER_LOW,
 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 = rtc_device_register(pdev->name, &pdev->dev,
 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         platform_set_drvdata(pdev, tps_rtc);
 289
 290         return 0;
 291 }
 292
 293 /*
 294  * Disable tps65910 RTC interrupts.
 295  * Sets status flag to free.
 296  */
 297 static int tps65910_rtc_remove(struct platform_device *pdev)
 298 {
 299         /* leave rtc running, but disable irqs */
 300         struct tps65910_rtc *tps_rtc = platform_get_drvdata(pdev);
 301
 302         tps65910_rtc_alarm_irq_enable(&pdev->dev, 0);
 303
 304         rtc_device_unregister(tps_rtc->rtc);
 305         return 0;
 306 }
 307
 308 #ifdef CONFIG_PM_SLEEP
 309
 310 static int tps65910_rtc_suspend(struct device *dev)
 311 {
 312         struct tps65910 *tps = dev_get_drvdata(dev->parent);
 313         struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
 314         u8 alarm = TPS65910_RTC_INTERRUPTS_IT_ALARM;
 315         int ret;
 316
 317         if (device_may_wakeup(dev))
 318                 enable_irq_wake(tps_rtc->irq);
 319
 320         /* Store current list of enabled interrupts*/
 321         ret = regmap_read(tps->regmap, TPS65910_RTC_INTERRUPTS,
 322                 &tps->rtc->irqstat);
 323         if (ret < 0)
 324                 return ret;
 325
 326         /* Enable RTC ALARM interrupt only */
 327         return regmap_write(tps->regmap, TPS65910_RTC_INTERRUPTS, alarm);
 328 }
 329
 330 static int tps65910_rtc_resume(struct device *dev)
 331 {
 332         struct tps65910 *tps = dev_get_drvdata(dev->parent);
 333         struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
 334
 335         if (device_may_wakeup(dev))
 336                 disable_irq_wake(tps_rtc->irq);
 337
 338         /* Restore list of enabled interrupts before suspend */
 339         return regmap_write(tps->regmap, TPS65910_RTC_INTERRUPTS,
 340                 tps->rtc->irqstat);
 341 }
 342
 343 static const struct dev_pm_ops tps65910_rtc_pm_ops = {
 344         .suspend        = tps65910_rtc_suspend,
 345         .resume         = tps65910_rtc_resume,
 346 };
 347
 348 #define DEV_PM_OPS     (&tps65910_rtc_pm_ops)
 349 #else
 350 #define DEV_PM_OPS     NULL
 351 #endif
 352
 353 static struct platform_driver tps65910_rtc_driver = {
 354         .probe          = tps65910_rtc_probe,
 355         .remove         = tps65910_rtc_remove,
 356         .driver         = {
 357                 .owner  = THIS_MODULE,
 358                 .name   = "tps65910-rtc",
 359                 .pm     = DEV_PM_OPS,
 360         },
 361 };
 362
 363 module_platform_driver(tps65910_rtc_driver);
 364 MODULE_ALIAS("platform:rtc-tps65910");
 365 MODULE_AUTHOR("Venu Byravarasu <vbyravarasu@nvidia.com>");
 366 MODULE_LICENSE("GPL");