drivers/rtc/rtc-tps6586x.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * rtc-tps6586x.c: RTC driver for TI PMIC TPS6586X
   4  *
   5  * Copyright (c) 2012, NVIDIA Corporation.
   6  *
   7  * Author: Laxman Dewangan <ldewangan@nvidia.com>
   8  */
   9
  10 #include <linux/device.h>
  11 #include <linux/err.h>
  12 #include <linux/init.h>
  13 #include <linux/irq.h>
  14 #include <linux/kernel.h>
  15 #include <linux/mfd/tps6586x.h>
  16 #include <linux/module.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/pm_runtime.h>
  19 #include <linux/rtc.h>
  20 #include <linux/slab.h>
  21
  22 #define RTC_CTRL                        0xc0
  23 #define POR_RESET_N                     BIT(7)
  24 #define OSC_SRC_SEL                     BIT(6)
  25 #define RTC_ENABLE                      BIT(5)  /* enables alarm */
  26 #define RTC_BUF_ENABLE                  BIT(4)  /* 32 KHz buffer enable */
  27 #define PRE_BYPASS                      BIT(3)  /* 0=1KHz or 1=32KHz updates */
  28 #define CL_SEL_MASK                     (BIT(2)|BIT(1))
  29 #define CL_SEL_POS                      1
  30 #define RTC_ALARM1_HI                   0xc1
  31 #define RTC_COUNT4                      0xc6
  32
  33 /* start a PMU RTC access by reading the register prior to the RTC_COUNT4 */
  34 #define RTC_COUNT4_DUMMYREAD            0xc5
  35
  36 /*only 14-bits width in second*/
  37 #define ALM1_VALID_RANGE_IN_SEC         0x3FFF
  38
  39 #define TPS6586X_RTC_CL_SEL_1_5PF       0x0
  40 #define TPS6586X_RTC_CL_SEL_6_5PF       0x1
  41 #define TPS6586X_RTC_CL_SEL_7_5PF       0x2
  42 #define TPS6586X_RTC_CL_SEL_12_5PF      0x3
  43
  44 struct tps6586x_rtc {
  45         struct device           *dev;
  46         struct rtc_device       *rtc;
  47         int                     irq;
  48         bool                    irq_en;
  49 };
  50
  51 static inline struct device *to_tps6586x_dev(struct device *dev)
  52 {
  53         return dev->parent;
  54 }
  55
  56 static int tps6586x_rtc_read_time(struct device *dev, struct rtc_time *tm)
  57 {
  58         struct device *tps_dev = to_tps6586x_dev(dev);
  59         unsigned long long ticks = 0;
  60         time64_t seconds;
  61         u8 buff[6];
  62         int ret;
  63         int i;
  64
  65         ret = tps6586x_reads(tps_dev, RTC_COUNT4_DUMMYREAD, sizeof(buff), buff);
  66         if (ret < 0) {
  67                 dev_err(dev, "read counter failed with err %d\n", ret);
  68                 return ret;
  69         }
  70
  71         for (i = 1; i < sizeof(buff); i++) {
  72                 ticks <<= 8;
  73                 ticks |= buff[i];
  74         }
  75
  76         seconds = ticks >> 10;
  77         rtc_time64_to_tm(seconds, tm);
  78
  79         return 0;
  80 }
  81
  82 static int tps6586x_rtc_set_time(struct device *dev, struct rtc_time *tm)
  83 {
  84         struct device *tps_dev = to_tps6586x_dev(dev);
  85         unsigned long long ticks;
  86         time64_t seconds;
  87         u8 buff[5];
  88         int ret;
  89
  90         seconds = rtc_tm_to_time64(tm);
  91
  92         ticks = (unsigned long long)seconds << 10;
  93         buff[0] = (ticks >> 32) & 0xff;
  94         buff[1] = (ticks >> 24) & 0xff;
  95         buff[2] = (ticks >> 16) & 0xff;
  96         buff[3] = (ticks >> 8) & 0xff;
  97         buff[4] = ticks & 0xff;
  98
  99         /* Disable RTC before changing time */
 100         ret = tps6586x_clr_bits(tps_dev, RTC_CTRL, RTC_ENABLE);
 101         if (ret < 0) {
 102                 dev_err(dev, "failed to clear RTC_ENABLE\n");
 103                 return ret;
 104         }
 105
 106         ret = tps6586x_writes(tps_dev, RTC_COUNT4, sizeof(buff), buff);
 107         if (ret < 0) {
 108                 dev_err(dev, "failed to program new time\n");
 109                 return ret;
 110         }
 111
 112         /* Enable RTC */
 113         ret = tps6586x_set_bits(tps_dev, RTC_CTRL, RTC_ENABLE);
 114         if (ret < 0) {
 115                 dev_err(dev, "failed to set RTC_ENABLE\n");
 116                 return ret;
 117         }
 118         return 0;
 119 }
 120
 121 static int tps6586x_rtc_alarm_irq_enable(struct device *dev,
 122                          unsigned int enabled)
 123 {
 124         struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
 125
 126         if (enabled && !rtc->irq_en) {
 127                 enable_irq(rtc->irq);
 128                 rtc->irq_en = true;
 129         } else if (!enabled && rtc->irq_en)  {
 130                 disable_irq(rtc->irq);
 131                 rtc->irq_en = false;
 132         }
 133         return 0;
 134 }
 135
 136 static int tps6586x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 137 {
 138         struct device *tps_dev = to_tps6586x_dev(dev);
 139         time64_t seconds;
 140         unsigned long ticks;
 141         unsigned long rtc_current_time;
 142         unsigned long long rticks = 0;
 143         u8 buff[3];
 144         u8 rbuff[6];
 145         int ret;
 146         int i;
 147
 148         seconds = rtc_tm_to_time64(&alrm->time);
 149
 150         ret = tps6586x_rtc_alarm_irq_enable(dev, alrm->enabled);
 151         if (ret < 0) {
 152                 dev_err(dev, "can't set alarm irq, err %d\n", ret);
 153                 return ret;
 154         }
 155
 156         ret = tps6586x_reads(tps_dev, RTC_COUNT4_DUMMYREAD,
 157                         sizeof(rbuff), rbuff);
 158         if (ret < 0) {
 159                 dev_err(dev, "read counter failed with err %d\n", ret);
 160                 return ret;
 161         }
 162
 163         for (i = 1; i < sizeof(rbuff); i++) {
 164                 rticks <<= 8;
 165                 rticks |= rbuff[i];
 166         }
 167
 168         rtc_current_time = rticks >> 10;
 169         if ((seconds - rtc_current_time) > ALM1_VALID_RANGE_IN_SEC)
 170                 seconds = rtc_current_time - 1;
 171
 172         ticks = (unsigned long long)seconds << 10;
 173         buff[0] = (ticks >> 16) & 0xff;
 174         buff[1] = (ticks >> 8) & 0xff;
 175         buff[2] = ticks & 0xff;
 176
 177         ret = tps6586x_writes(tps_dev, RTC_ALARM1_HI, sizeof(buff), buff);
 178         if (ret)
 179                 dev_err(dev, "programming alarm failed with err %d\n", ret);
 180
 181         return ret;
 182 }
 183
 184 static int tps6586x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 185 {
 186         struct device *tps_dev = to_tps6586x_dev(dev);
 187         unsigned long ticks;
 188         time64_t seconds;
 189         u8 buff[3];
 190         int ret;
 191
 192         ret = tps6586x_reads(tps_dev, RTC_ALARM1_HI, sizeof(buff), buff);
 193         if (ret) {
 194                 dev_err(dev, "read RTC_ALARM1_HI failed with err %d\n", ret);
 195                 return ret;
 196         }
 197
 198         ticks = (buff[0] << 16) | (buff[1] << 8) | buff[2];
 199         seconds = ticks >> 10;
 200
 201         rtc_time64_to_tm(seconds, &alrm->time);
 202         return 0;
 203 }
 204
 205 static const struct rtc_class_ops tps6586x_rtc_ops = {
 206         .read_time      = tps6586x_rtc_read_time,
 207         .set_time       = tps6586x_rtc_set_time,
 208         .set_alarm      = tps6586x_rtc_set_alarm,
 209         .read_alarm     = tps6586x_rtc_read_alarm,
 210         .alarm_irq_enable = tps6586x_rtc_alarm_irq_enable,
 211 };
 212
 213 static irqreturn_t tps6586x_rtc_irq(int irq, void *data)
 214 {
 215         struct tps6586x_rtc *rtc = data;
 216
 217         rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
 218         return IRQ_HANDLED;
 219 }
 220
 221 static int tps6586x_rtc_probe(struct platform_device *pdev)
 222 {
 223         struct device *tps_dev = to_tps6586x_dev(&pdev->dev);
 224         struct tps6586x_rtc *rtc;
 225         int ret;
 226
 227         rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
 228         if (!rtc)
 229                 return -ENOMEM;
 230
 231         rtc->dev = &pdev->dev;
 232         rtc->irq = platform_get_irq(pdev, 0);
 233
 234         /* 1 kHz tick mode, enable tick counting */
 235         ret = tps6586x_update(tps_dev, RTC_CTRL,
 236                 RTC_ENABLE | OSC_SRC_SEL |
 237                 ((TPS6586X_RTC_CL_SEL_1_5PF << CL_SEL_POS) & CL_SEL_MASK),
 238                 RTC_ENABLE | OSC_SRC_SEL | PRE_BYPASS | CL_SEL_MASK);
 239         if (ret < 0) {
 240                 dev_err(&pdev->dev, "unable to start counter\n");
 241                 return ret;
 242         }
 243
 244         device_init_wakeup(&pdev->dev, 1);
 245
 246         platform_set_drvdata(pdev, rtc);
 247         rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
 248         if (IS_ERR(rtc->rtc)) {
 249                 ret = PTR_ERR(rtc->rtc);
 250                 goto fail_rtc_register;
 251         }
 252
 253         rtc->rtc->ops = &tps6586x_rtc_ops;
 254         rtc->rtc->range_max = (1ULL << 30) - 1; /* 30-bit seconds */
 255         rtc->rtc->start_secs = mktime64(2009, 1, 1, 0, 0, 0);
 256         rtc->rtc->set_start_time = true;
 257
 258         irq_set_status_flags(rtc->irq, IRQ_NOAUTOEN);
 259
 260         ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
 261                                 tps6586x_rtc_irq,
 262                                 IRQF_ONESHOT,
 263                                 dev_name(&pdev->dev), rtc);
 264         if (ret < 0) {
 265                 dev_err(&pdev->dev, "request IRQ(%d) failed with ret %d\n",
 266                                 rtc->irq, ret);
 267                 goto fail_rtc_register;
 268         }
 269
 270         ret = devm_rtc_register_device(rtc->rtc);
 271         if (ret)
 272                 goto fail_rtc_register;
 273
 274         return 0;
 275
 276 fail_rtc_register:
 277         tps6586x_update(tps_dev, RTC_CTRL, 0,
 278                 RTC_ENABLE | OSC_SRC_SEL | PRE_BYPASS | CL_SEL_MASK);
 279         return ret;
 280 };
 281
 282 static int tps6586x_rtc_remove(struct platform_device *pdev)
 283 {
 284         struct device *tps_dev = to_tps6586x_dev(&pdev->dev);
 285
 286         tps6586x_update(tps_dev, RTC_CTRL, 0,
 287                 RTC_ENABLE | OSC_SRC_SEL | PRE_BYPASS | CL_SEL_MASK);
 288         return 0;
 289 }
 290
 291 #ifdef CONFIG_PM_SLEEP
 292 static int tps6586x_rtc_suspend(struct device *dev)
 293 {
 294         struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
 295
 296         if (device_may_wakeup(dev))
 297                 enable_irq_wake(rtc->irq);
 298         return 0;
 299 }
 300
 301 static int tps6586x_rtc_resume(struct device *dev)
 302 {
 303         struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
 304
 305         if (device_may_wakeup(dev))
 306                 disable_irq_wake(rtc->irq);
 307         return 0;
 308 }
 309 #endif
 310
 311 static SIMPLE_DEV_PM_OPS(tps6586x_pm_ops, tps6586x_rtc_suspend,
 312                         tps6586x_rtc_resume);
 313
 314 static struct platform_driver tps6586x_rtc_driver = {
 315         .driver = {
 316                 .name   = "tps6586x-rtc",
 317                 .pm     = &tps6586x_pm_ops,
 318         },
 319         .probe  = tps6586x_rtc_probe,
 320         .remove = tps6586x_rtc_remove,
 321 };
 322 module_platform_driver(tps6586x_rtc_driver);
 323
 324 MODULE_ALIAS("platform:tps6586x-rtc");
 325 MODULE_DESCRIPTION("TI TPS6586x RTC driver");
 326 MODULE_AUTHOR("Laxman dewangan <ldewangan@nvidia.com>");
 327 MODULE_LICENSE("GPL v2");