drivers/rtc/rtc-palmas.c

   1 /*
   2  * rtc-palmas.c -- Palmas Real Time Clock driver.
   3
   4  * RTC driver for TI Palma series devices like TPS65913,
   5  * TPS65914 power management IC.
   6  *
   7  * Copyright (c) 2012, NVIDIA Corporation.
   8  *
   9  * Author: Laxman Dewangan <ldewangan@nvidia.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 as
  13  * published by the Free Software Foundation version 2.
  14  *
  15  * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
  16  * whether express or implied; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  23  * 02111-1307, USA
  24  */
  25
  26 #include <linux/bcd.h>
  27 #include <linux/errno.h>
  28 #include <linux/init.h>
  29 #include <linux/interrupt.h>
  30 #include <linux/kernel.h>
  31 #include <linux/mfd/palmas.h>
  32 #include <linux/module.h>
  33 #include <linux/rtc.h>
  34 #include <linux/types.h>
  35 #include <linux/platform_device.h>
  36 #include <linux/pm.h>
  37
  38 struct palmas_rtc {
  39         struct rtc_device       *rtc;
  40         struct device           *dev;
  41         unsigned int            irq;
  42 };
  43
  44 /* Total number of RTC registers needed to set time*/
  45 #define PALMAS_NUM_TIME_REGS    (PALMAS_YEARS_REG - PALMAS_SECONDS_REG + 1)
  46
  47 static int palmas_rtc_read_time(struct device *dev, struct rtc_time *tm)
  48 {
  49         unsigned char rtc_data[PALMAS_NUM_TIME_REGS];
  50         struct palmas *palmas = dev_get_drvdata(dev->parent);
  51         int ret;
  52
  53         /* Copy RTC counting registers to static registers or latches */
  54         ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
  55                 PALMAS_RTC_CTRL_REG_GET_TIME, PALMAS_RTC_CTRL_REG_GET_TIME);
  56         if (ret < 0) {
  57                 dev_err(dev, "RTC CTRL reg update failed, err: %d\n", ret);
  58                 return ret;
  59         }
  60
  61         ret = palmas_bulk_read(palmas, PALMAS_RTC_BASE, PALMAS_SECONDS_REG,
  62                         rtc_data, PALMAS_NUM_TIME_REGS);
  63         if (ret < 0) {
  64                 dev_err(dev, "RTC_SECONDS reg read failed, err = %d\n", ret);
  65                 return ret;
  66         }
  67
  68         tm->tm_sec = bcd2bin(rtc_data[0]);
  69         tm->tm_min = bcd2bin(rtc_data[1]);
  70         tm->tm_hour = bcd2bin(rtc_data[2]);
  71         tm->tm_mday = bcd2bin(rtc_data[3]);
  72         tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
  73         tm->tm_year = bcd2bin(rtc_data[5]) + 100;
  74
  75         return ret;
  76 }
  77
  78 static int palmas_rtc_set_time(struct device *dev, struct rtc_time *tm)
  79 {
  80         unsigned char rtc_data[PALMAS_NUM_TIME_REGS];
  81         struct palmas *palmas = dev_get_drvdata(dev->parent);
  82         int ret;
  83
  84         rtc_data[0] = bin2bcd(tm->tm_sec);
  85         rtc_data[1] = bin2bcd(tm->tm_min);
  86         rtc_data[2] = bin2bcd(tm->tm_hour);
  87         rtc_data[3] = bin2bcd(tm->tm_mday);
  88         rtc_data[4] = bin2bcd(tm->tm_mon + 1);
  89         rtc_data[5] = bin2bcd(tm->tm_year - 100);
  90
  91         /* Stop RTC while updating the RTC time registers */
  92         ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
  93                 PALMAS_RTC_CTRL_REG_STOP_RTC, 0);
  94         if (ret < 0) {
  95                 dev_err(dev, "RTC stop failed, err = %d\n", ret);
  96                 return ret;
  97         }
  98
  99         ret = palmas_bulk_write(palmas, PALMAS_RTC_BASE, PALMAS_SECONDS_REG,
 100                 rtc_data, PALMAS_NUM_TIME_REGS);
 101         if (ret < 0) {
 102                 dev_err(dev, "RTC_SECONDS reg write failed, err = %d\n", ret);
 103                 return ret;
 104         }
 105
 106         /* Start back RTC */
 107         ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
 108                 PALMAS_RTC_CTRL_REG_STOP_RTC, PALMAS_RTC_CTRL_REG_STOP_RTC);
 109         if (ret < 0)
 110                 dev_err(dev, "RTC start failed, err = %d\n", ret);
 111         return ret;
 112 }
 113
 114 static int palmas_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
 115 {
 116         struct palmas *palmas = dev_get_drvdata(dev->parent);
 117         u8 val;
 118
 119         val = enabled ? PALMAS_RTC_INTERRUPTS_REG_IT_ALARM : 0;
 120         return palmas_write(palmas, PALMAS_RTC_BASE,
 121                 PALMAS_RTC_INTERRUPTS_REG, val);
 122 }
 123
 124 static int palmas_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
 125 {
 126         unsigned char alarm_data[PALMAS_NUM_TIME_REGS];
 127         u32 int_val;
 128         struct palmas *palmas = dev_get_drvdata(dev->parent);
 129         int ret;
 130
 131         ret = palmas_bulk_read(palmas, PALMAS_RTC_BASE,
 132                         PALMAS_ALARM_SECONDS_REG,
 133                         alarm_data, PALMAS_NUM_TIME_REGS);
 134         if (ret < 0) {
 135                 dev_err(dev, "RTC_ALARM_SECONDS read failed, err = %d\n", ret);
 136                 return ret;
 137         }
 138
 139         alm->time.tm_sec = bcd2bin(alarm_data[0]);
 140         alm->time.tm_min = bcd2bin(alarm_data[1]);
 141         alm->time.tm_hour = bcd2bin(alarm_data[2]);
 142         alm->time.tm_mday = bcd2bin(alarm_data[3]);
 143         alm->time.tm_mon = bcd2bin(alarm_data[4]) - 1;
 144         alm->time.tm_year = bcd2bin(alarm_data[5]) + 100;
 145
 146         ret = palmas_read(palmas, PALMAS_RTC_BASE, PALMAS_RTC_INTERRUPTS_REG,
 147                         &int_val);
 148         if (ret < 0) {
 149                 dev_err(dev, "RTC_INTERRUPTS reg read failed, err = %d\n", ret);
 150                 return ret;
 151         }
 152
 153         if (int_val & PALMAS_RTC_INTERRUPTS_REG_IT_ALARM)
 154                 alm->enabled = 1;
 155         return ret;
 156 }
 157
 158 static int palmas_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 159 {
 160         unsigned char alarm_data[PALMAS_NUM_TIME_REGS];
 161         struct palmas *palmas = dev_get_drvdata(dev->parent);
 162         int ret;
 163
 164         ret = palmas_rtc_alarm_irq_enable(dev, 0);
 165         if (ret < 0) {
 166                 dev_err(dev, "Disable RTC alarm failed\n");
 167                 return ret;
 168         }
 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         ret = palmas_bulk_write(palmas, PALMAS_RTC_BASE,
 178                 PALMAS_ALARM_SECONDS_REG, alarm_data, PALMAS_NUM_TIME_REGS);
 179         if (ret < 0) {
 180                 dev_err(dev, "ALARM_SECONDS_REG write failed, err = %d\n", ret);
 181                 return ret;
 182         }
 183
 184         if (alm->enabled)
 185                 ret = palmas_rtc_alarm_irq_enable(dev, 1);
 186         return ret;
 187 }
 188
 189 static int palmas_clear_interrupts(struct device *dev)
 190 {
 191         struct palmas *palmas = dev_get_drvdata(dev->parent);
 192         unsigned int rtc_reg;
 193         int ret;
 194
 195         ret = palmas_read(palmas, PALMAS_RTC_BASE, PALMAS_RTC_STATUS_REG,
 196                                 &rtc_reg);
 197         if (ret < 0) {
 198                 dev_err(dev, "RTC_STATUS read failed, err = %d\n", ret);
 199                 return ret;
 200         }
 201
 202         ret = palmas_write(palmas, PALMAS_RTC_BASE, PALMAS_RTC_STATUS_REG,
 203                         rtc_reg);
 204         if (ret < 0) {
 205                 dev_err(dev, "RTC_STATUS write failed, err = %d\n", ret);
 206                 return ret;
 207         }
 208         return 0;
 209 }
 210
 211 static irqreturn_t palmas_rtc_interrupt(int irq, void *context)
 212 {
 213         struct palmas_rtc *palmas_rtc = context;
 214         struct device *dev = palmas_rtc->dev;
 215         int ret;
 216
 217         ret = palmas_clear_interrupts(dev);
 218         if (ret < 0) {
 219                 dev_err(dev, "RTC interrupt clear failed, err = %d\n", ret);
 220                 return IRQ_NONE;
 221         }
 222
 223         rtc_update_irq(palmas_rtc->rtc, 1, RTC_IRQF | RTC_AF);
 224         return IRQ_HANDLED;
 225 }
 226
 227 static struct rtc_class_ops palmas_rtc_ops = {
 228         .read_time      = palmas_rtc_read_time,
 229         .set_time       = palmas_rtc_set_time,
 230         .read_alarm     = palmas_rtc_read_alarm,
 231         .set_alarm      = palmas_rtc_set_alarm,
 232         .alarm_irq_enable = palmas_rtc_alarm_irq_enable,
 233 };
 234
 235 static int palmas_rtc_probe(struct platform_device *pdev)
 236 {
 237         struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
 238         struct palmas_rtc *palmas_rtc = NULL;
 239         int ret;
 240
 241         palmas_rtc = devm_kzalloc(&pdev->dev, sizeof(struct palmas_rtc),
 242                         GFP_KERNEL);
 243         if (!palmas_rtc)
 244                 return -ENOMEM;
 245
 246         /* Clear pending interrupts */
 247         ret = palmas_clear_interrupts(&pdev->dev);
 248         if (ret < 0) {
 249                 dev_err(&pdev->dev, "clear RTC int failed, err = %d\n", ret);
 250                 return ret;
 251         }
 252
 253         palmas_rtc->dev = &pdev->dev;
 254         platform_set_drvdata(pdev, palmas_rtc);
 255
 256         /* Start RTC */
 257         ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
 258                         PALMAS_RTC_CTRL_REG_STOP_RTC,
 259                         PALMAS_RTC_CTRL_REG_STOP_RTC);
 260         if (ret < 0) {
 261                 dev_err(&pdev->dev, "RTC_CTRL write failed, err = %d\n", ret);
 262                 return ret;
 263         }
 264
 265         palmas_rtc->irq = platform_get_irq(pdev, 0);
 266
 267         palmas_rtc->rtc = rtc_device_register(pdev->name, &pdev->dev,
 268                                 &palmas_rtc_ops, THIS_MODULE);
 269         if (IS_ERR(palmas_rtc->rtc)) {
 270                 ret = PTR_ERR(palmas_rtc->rtc);
 271                 dev_err(&pdev->dev, "RTC register failed, err = %d\n", ret);
 272                 return ret;
 273         }
 274
 275         ret = request_threaded_irq(palmas_rtc->irq, NULL,
 276                         palmas_rtc_interrupt,
 277                         IRQF_TRIGGER_LOW | IRQF_ONESHOT |
 278                         IRQF_EARLY_RESUME,
 279                         dev_name(&pdev->dev), palmas_rtc);
 280         if (ret < 0) {
 281                 dev_err(&pdev->dev, "IRQ request failed, err = %d\n", ret);
 282                 rtc_device_unregister(palmas_rtc->rtc);
 283                 return ret;
 284         }
 285
 286         device_set_wakeup_capable(&pdev->dev, 1);
 287         return 0;
 288 }
 289
 290 static int palmas_rtc_remove(struct platform_device *pdev)
 291 {
 292         struct palmas_rtc *palmas_rtc = platform_get_drvdata(pdev);
 293
 294         palmas_rtc_alarm_irq_enable(&pdev->dev, 0);
 295         free_irq(palmas_rtc->irq, palmas_rtc);
 296         rtc_device_unregister(palmas_rtc->rtc);
 297         return 0;
 298 }
 299
 300 #ifdef CONFIG_PM_SLEEP
 301 static int palmas_rtc_suspend(struct device *dev)
 302 {
 303         struct palmas_rtc *palmas_rtc = dev_get_drvdata(dev);
 304
 305         if (device_may_wakeup(dev))
 306                 enable_irq_wake(palmas_rtc->irq);
 307         return 0;
 308 }
 309
 310 static int palmas_rtc_resume(struct device *dev)
 311 {
 312         struct palmas_rtc *palmas_rtc = dev_get_drvdata(dev);
 313
 314         if (device_may_wakeup(dev))
 315                 disable_irq_wake(palmas_rtc->irq);
 316         return 0;
 317 }
 318 #endif
 319
 320 static const struct dev_pm_ops palmas_rtc_pm_ops = {
 321         SET_SYSTEM_SLEEP_PM_OPS(palmas_rtc_suspend, palmas_rtc_resume)
 322 };
 323
 324 static struct platform_driver palmas_rtc_driver = {
 325         .probe          = palmas_rtc_probe,
 326         .remove         = palmas_rtc_remove,
 327         .driver         = {
 328                 .owner  = THIS_MODULE,
 329                 .name   = "palmas-rtc",
 330                 .pm     = &palmas_rtc_pm_ops,
 331         },
 332 };
 333
 334 module_platform_driver(palmas_rtc_driver);
 335
 336 MODULE_ALIAS("platform:palmas_rtc");
 337 MODULE_DESCRIPTION("TI PALMAS series RTC driver");
 338 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
 339 MODULE_LICENSE("GPL v2");