drivers/rtc/rtc-hym8563.c

   1 /*
   2  * Haoyu HYM8563 RTC driver
   3  *
   4  * Copyright (C) 2013 MundoReader S.L.
   5  * Author: Heiko Stuebner <heiko@sntech.de>
   6  *
   7  * based on rtc-HYM8563
   8  * Copyright (C) 2010 ROCKCHIP, Inc.
   9  *
  10  * This software is licensed under the terms of the GNU General Public
  11  * License version 2, as published by the Free Software Foundation, and
  12  * may be copied, distributed, and modified under those terms.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  */
  19
  20 #include <linux/module.h>
  21 #include <linux/clk-provider.h>
  22 #include <linux/i2c.h>
  23 #include <linux/bcd.h>
  24 #include <linux/rtc.h>
  25
  26 #define HYM8563_CTL1            0x00
  27 #define HYM8563_CTL1_TEST       BIT(7)
  28 #define HYM8563_CTL1_STOP       BIT(5)
  29 #define HYM8563_CTL1_TESTC      BIT(3)
  30
  31 #define HYM8563_CTL2            0x01
  32 #define HYM8563_CTL2_TI_TP      BIT(4)
  33 #define HYM8563_CTL2_AF         BIT(3)
  34 #define HYM8563_CTL2_TF         BIT(2)
  35 #define HYM8563_CTL2_AIE        BIT(1)
  36 #define HYM8563_CTL2_TIE        BIT(0)
  37
  38 #define HYM8563_SEC             0x02
  39 #define HYM8563_SEC_VL          BIT(7)
  40 #define HYM8563_SEC_MASK        0x7f
  41
  42 #define HYM8563_MIN             0x03
  43 #define HYM8563_MIN_MASK        0x7f
  44
  45 #define HYM8563_HOUR            0x04
  46 #define HYM8563_HOUR_MASK       0x3f
  47
  48 #define HYM8563_DAY             0x05
  49 #define HYM8563_DAY_MASK        0x3f
  50
  51 #define HYM8563_WEEKDAY         0x06
  52 #define HYM8563_WEEKDAY_MASK    0x07
  53
  54 #define HYM8563_MONTH           0x07
  55 #define HYM8563_MONTH_CENTURY   BIT(7)
  56 #define HYM8563_MONTH_MASK      0x1f
  57
  58 #define HYM8563_YEAR            0x08
  59
  60 #define HYM8563_ALM_MIN         0x09
  61 #define HYM8563_ALM_HOUR        0x0a
  62 #define HYM8563_ALM_DAY         0x0b
  63 #define HYM8563_ALM_WEEK        0x0c
  64
  65 /* Each alarm check can be disabled by setting this bit in the register */
  66 #define HYM8563_ALM_BIT_DISABLE BIT(7)
  67
  68 #define HYM8563_CLKOUT          0x0d
  69 #define HYM8563_CLKOUT_ENABLE   BIT(7)
  70 #define HYM8563_CLKOUT_32768    0
  71 #define HYM8563_CLKOUT_1024     1
  72 #define HYM8563_CLKOUT_32       2
  73 #define HYM8563_CLKOUT_1        3
  74 #define HYM8563_CLKOUT_MASK     3
  75
  76 #define HYM8563_TMR_CTL         0x0e
  77 #define HYM8563_TMR_CTL_ENABLE  BIT(7)
  78 #define HYM8563_TMR_CTL_4096    0
  79 #define HYM8563_TMR_CTL_64      1
  80 #define HYM8563_TMR_CTL_1       2
  81 #define HYM8563_TMR_CTL_1_60    3
  82 #define HYM8563_TMR_CTL_MASK    3
  83
  84 #define HYM8563_TMR_CNT         0x0f
  85
  86 struct hym8563 {
  87         struct i2c_client       *client;
  88         struct rtc_device       *rtc;
  89         bool                    valid;
  90 #ifdef CONFIG_COMMON_CLK
  91         struct clk_hw           clkout_hw;
  92 #endif
  93 };
  94
  95 /*
  96  * RTC handling
  97  */
  98
  99 static int hym8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
 100 {
 101         struct i2c_client *client = to_i2c_client(dev);
 102         struct hym8563 *hym8563 = i2c_get_clientdata(client);
 103         u8 buf[7];
 104         int ret;
 105
 106         if (!hym8563->valid) {
 107                 dev_warn(&client->dev, "no valid clock/calendar values available\n");
 108                 return -EPERM;
 109         }
 110
 111         ret = i2c_smbus_read_i2c_block_data(client, HYM8563_SEC, 7, buf);
 112
 113         tm->tm_sec = bcd2bin(buf[0] & HYM8563_SEC_MASK);
 114         tm->tm_min = bcd2bin(buf[1] & HYM8563_MIN_MASK);
 115         tm->tm_hour = bcd2bin(buf[2] & HYM8563_HOUR_MASK);
 116         tm->tm_mday = bcd2bin(buf[3] & HYM8563_DAY_MASK);
 117         tm->tm_wday = bcd2bin(buf[4] & HYM8563_WEEKDAY_MASK); /* 0 = Sun */
 118         tm->tm_mon = bcd2bin(buf[5] & HYM8563_MONTH_MASK) - 1; /* 0 = Jan */
 119         tm->tm_year = bcd2bin(buf[6]) + 100;
 120
 121         return 0;
 122 }
 123
 124 static int hym8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
 125 {
 126         struct i2c_client *client = to_i2c_client(dev);
 127         struct hym8563 *hym8563 = i2c_get_clientdata(client);
 128         u8 buf[7];
 129         int ret;
 130
 131         /* Years >= 2100 are to far in the future, 19XX is to early */
 132         if (tm->tm_year < 100 || tm->tm_year >= 200)
 133                 return -EINVAL;
 134
 135         buf[0] = bin2bcd(tm->tm_sec);
 136         buf[1] = bin2bcd(tm->tm_min);
 137         buf[2] = bin2bcd(tm->tm_hour);
 138         buf[3] = bin2bcd(tm->tm_mday);
 139         buf[4] = bin2bcd(tm->tm_wday);
 140         buf[5] = bin2bcd(tm->tm_mon + 1);
 141
 142         /*
 143          * While the HYM8563 has a century flag in the month register,
 144          * it does not seem to carry it over a subsequent write/read.
 145          * So we'll limit ourself to 100 years, starting at 2000 for now.
 146          */
 147         buf[6] = bin2bcd(tm->tm_year - 100);
 148
 149         /*
 150          * CTL1 only contains TEST-mode bits apart from stop,
 151          * so no need to read the value first
 152          */
 153         ret = i2c_smbus_write_byte_data(client, HYM8563_CTL1,
 154                                                 HYM8563_CTL1_STOP);
 155         if (ret < 0)
 156                 return ret;
 157
 158         ret = i2c_smbus_write_i2c_block_data(client, HYM8563_SEC, 7, buf);
 159         if (ret < 0)
 160                 return ret;
 161
 162         ret = i2c_smbus_write_byte_data(client, HYM8563_CTL1, 0);
 163         if (ret < 0)
 164                 return ret;
 165
 166         hym8563->valid = true;
 167
 168         return 0;
 169 }
 170
 171 static int hym8563_rtc_alarm_irq_enable(struct device *dev,
 172                                         unsigned int enabled)
 173 {
 174         struct i2c_client *client = to_i2c_client(dev);
 175         int data;
 176
 177         data = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
 178         if (data < 0)
 179                 return data;
 180
 181         if (enabled)
 182                 data |= HYM8563_CTL2_AIE;
 183         else
 184                 data &= ~HYM8563_CTL2_AIE;
 185
 186         return i2c_smbus_write_byte_data(client, HYM8563_CTL2, data);
 187 };
 188
 189 static int hym8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
 190 {
 191         struct i2c_client *client = to_i2c_client(dev);
 192         struct rtc_time *alm_tm = &alm->time;
 193         u8 buf[4];
 194         int ret;
 195
 196         ret = i2c_smbus_read_i2c_block_data(client, HYM8563_ALM_MIN, 4, buf);
 197         if (ret < 0)
 198                 return ret;
 199
 200         /* The alarm only has a minute accuracy */
 201         alm_tm->tm_sec = 0;
 202
 203         alm_tm->tm_min = (buf[0] & HYM8563_ALM_BIT_DISABLE) ?
 204                                         -1 :
 205                                         bcd2bin(buf[0] & HYM8563_MIN_MASK);
 206         alm_tm->tm_hour = (buf[1] & HYM8563_ALM_BIT_DISABLE) ?
 207                                         -1 :
 208                                         bcd2bin(buf[1] & HYM8563_HOUR_MASK);
 209         alm_tm->tm_mday = (buf[2] & HYM8563_ALM_BIT_DISABLE) ?
 210                                         -1 :
 211                                         bcd2bin(buf[2] & HYM8563_DAY_MASK);
 212         alm_tm->tm_wday = (buf[3] & HYM8563_ALM_BIT_DISABLE) ?
 213                                         -1 :
 214                                         bcd2bin(buf[3] & HYM8563_WEEKDAY_MASK);
 215
 216         ret = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
 217         if (ret < 0)
 218                 return ret;
 219
 220         if (ret & HYM8563_CTL2_AIE)
 221                 alm->enabled = 1;
 222
 223         return 0;
 224 }
 225
 226 static int hym8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 227 {
 228         struct i2c_client *client = to_i2c_client(dev);
 229         struct rtc_time *alm_tm = &alm->time;
 230         u8 buf[4];
 231         int ret;
 232
 233         /*
 234          * The alarm has no seconds so deal with it
 235          */
 236         if (alm_tm->tm_sec) {
 237                 alm_tm->tm_sec = 0;
 238                 alm_tm->tm_min++;
 239                 if (alm_tm->tm_min >= 60) {
 240                         alm_tm->tm_min = 0;
 241                         alm_tm->tm_hour++;
 242                         if (alm_tm->tm_hour >= 24) {
 243                                 alm_tm->tm_hour = 0;
 244                                 alm_tm->tm_mday++;
 245                                 if (alm_tm->tm_mday > 31)
 246                                         alm_tm->tm_mday = 0;
 247                         }
 248                 }
 249         }
 250
 251         ret = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
 252         if (ret < 0)
 253                 return ret;
 254
 255         ret &= ~HYM8563_CTL2_AIE;
 256
 257         ret = i2c_smbus_write_byte_data(client, HYM8563_CTL2, ret);
 258         if (ret < 0)
 259                 return ret;
 260
 261         buf[0] = (alm_tm->tm_min < 60 && alm_tm->tm_min >= 0) ?
 262                         bin2bcd(alm_tm->tm_min) : HYM8563_ALM_BIT_DISABLE;
 263
 264         buf[1] = (alm_tm->tm_hour < 24 && alm_tm->tm_hour >= 0) ?
 265                         bin2bcd(alm_tm->tm_hour) : HYM8563_ALM_BIT_DISABLE;
 266
 267         buf[2] = (alm_tm->tm_mday <= 31 && alm_tm->tm_mday >= 1) ?
 268                         bin2bcd(alm_tm->tm_mday) : HYM8563_ALM_BIT_DISABLE;
 269
 270         buf[3] = (alm_tm->tm_wday < 7 && alm_tm->tm_wday >= 0) ?
 271                         bin2bcd(alm_tm->tm_wday) : HYM8563_ALM_BIT_DISABLE;
 272
 273         ret = i2c_smbus_write_i2c_block_data(client, HYM8563_ALM_MIN, 4, buf);
 274         if (ret < 0)
 275                 return ret;
 276
 277         return hym8563_rtc_alarm_irq_enable(dev, alm->enabled);
 278 }
 279
 280 static const struct rtc_class_ops hym8563_rtc_ops = {
 281         .read_time              = hym8563_rtc_read_time,
 282         .set_time               = hym8563_rtc_set_time,
 283         .alarm_irq_enable       = hym8563_rtc_alarm_irq_enable,
 284         .read_alarm             = hym8563_rtc_read_alarm,
 285         .set_alarm              = hym8563_rtc_set_alarm,
 286 };
 287
 288 /*
 289  * Handling of the clkout
 290  */
 291
 292 #ifdef CONFIG_COMMON_CLK
 293 #define clkout_hw_to_hym8563(_hw) container_of(_hw, struct hym8563, clkout_hw)
 294
 295 static int clkout_rates[] = {
 296         32768,
 297         1024,
 298         32,
 299         1,
 300 };
 301
 302 static unsigned long hym8563_clkout_recalc_rate(struct clk_hw *hw,
 303                                                 unsigned long parent_rate)
 304 {
 305         struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
 306         struct i2c_client *client = hym8563->client;
 307         int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);
 308
 309         if (ret < 0)
 310                 return 0;
 311
 312         ret &= HYM8563_CLKOUT_MASK;
 313         return clkout_rates[ret];
 314 }
 315
 316 static long hym8563_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
 317                                       unsigned long *prate)
 318 {
 319         int i;
 320
 321         for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
 322                 if (clkout_rates[i] <= rate)
 323                         return clkout_rates[i];
 324
 325         return 0;
 326 }
 327
 328 static int hym8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
 329                                    unsigned long parent_rate)
 330 {
 331         struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
 332         struct i2c_client *client = hym8563->client;
 333         int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);
 334         int i;
 335
 336         if (ret < 0)
 337                 return ret;
 338
 339         for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
 340                 if (clkout_rates[i] == rate) {
 341                         ret &= ~HYM8563_CLKOUT_MASK;
 342                         ret |= i;
 343                         return i2c_smbus_write_byte_data(client,
 344                                                          HYM8563_CLKOUT, ret);
 345                 }
 346
 347         return -EINVAL;
 348 }
 349
 350 static int hym8563_clkout_control(struct clk_hw *hw, bool enable)
 351 {
 352         struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
 353         struct i2c_client *client = hym8563->client;
 354         int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);
 355
 356         if (ret < 0)
 357                 return ret;
 358
 359         if (enable)
 360                 ret |= HYM8563_CLKOUT_ENABLE;
 361         else
 362                 ret &= ~HYM8563_CLKOUT_ENABLE;
 363
 364         return i2c_smbus_write_byte_data(client, HYM8563_CLKOUT, ret);
 365 }
 366
 367 static int hym8563_clkout_prepare(struct clk_hw *hw)
 368 {
 369         return hym8563_clkout_control(hw, 1);
 370 }
 371
 372 static void hym8563_clkout_unprepare(struct clk_hw *hw)
 373 {
 374         hym8563_clkout_control(hw, 0);
 375 }
 376
 377 static int hym8563_clkout_is_prepared(struct clk_hw *hw)
 378 {
 379         struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
 380         struct i2c_client *client = hym8563->client;
 381         int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);
 382
 383         if (ret < 0)
 384                 return ret;
 385
 386         return !!(ret & HYM8563_CLKOUT_ENABLE);
 387 }
 388
 389 static const struct clk_ops hym8563_clkout_ops = {
 390         .prepare = hym8563_clkout_prepare,
 391         .unprepare = hym8563_clkout_unprepare,
 392         .is_prepared = hym8563_clkout_is_prepared,
 393         .recalc_rate = hym8563_clkout_recalc_rate,
 394         .round_rate = hym8563_clkout_round_rate,
 395         .set_rate = hym8563_clkout_set_rate,
 396 };
 397
 398 static struct clk *hym8563_clkout_register_clk(struct hym8563 *hym8563)
 399 {
 400         struct i2c_client *client = hym8563->client;
 401         struct device_node *node = client->dev.of_node;
 402         struct clk *clk;
 403         struct clk_init_data init;
 404         int ret;
 405
 406         ret = i2c_smbus_write_byte_data(client, HYM8563_CLKOUT,
 407                                                 0);
 408         if (ret < 0)
 409                 return ERR_PTR(ret);
 410
 411         init.name = "hym8563-clkout";
 412         init.ops = &hym8563_clkout_ops;
 413         init.flags = 0;
 414         init.parent_names = NULL;
 415         init.num_parents = 0;
 416         hym8563->clkout_hw.init = &init;
 417
 418         /* optional override of the clockname */
 419         of_property_read_string(node, "clock-output-names", &init.name);
 420
 421         /* register the clock */
 422         clk = clk_register(&client->dev, &hym8563->clkout_hw);
 423
 424         if (!IS_ERR(clk))
 425                 of_clk_add_provider(node, of_clk_src_simple_get, clk);
 426
 427         return clk;
 428 }
 429 #endif
 430
 431 /*
 432  * The alarm interrupt is implemented as a level-low interrupt in the
 433  * hym8563, while the timer interrupt uses a falling edge.
 434  * We don't use the timer at all, so the interrupt is requested to
 435  * use the level-low trigger.
 436  */
 437 static irqreturn_t hym8563_irq(int irq, void *dev_id)
 438 {
 439         struct hym8563 *hym8563 = (struct hym8563 *)dev_id;
 440         struct i2c_client *client = hym8563->client;
 441         struct mutex *lock = &hym8563->rtc->ops_lock;
 442         int data, ret;
 443
 444         mutex_lock(lock);
 445
 446         /* Clear the alarm flag */
 447
 448         data = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
 449         if (data < 0) {
 450                 dev_err(&client->dev, "%s: error reading i2c data %d\n",
 451                         __func__, data);
 452                 goto out;
 453         }
 454
 455         data &= ~HYM8563_CTL2_AF;
 456
 457         ret = i2c_smbus_write_byte_data(client, HYM8563_CTL2, data);
 458         if (ret < 0) {
 459                 dev_err(&client->dev, "%s: error writing i2c data %d\n",
 460                         __func__, ret);
 461         }
 462
 463 out:
 464         mutex_unlock(lock);
 465         return IRQ_HANDLED;
 466 }
 467
 468 static int hym8563_init_device(struct i2c_client *client)
 469 {
 470         int ret;
 471
 472         /* Clear stop flag if present */
 473         ret = i2c_smbus_write_byte_data(client, HYM8563_CTL1, 0);
 474         if (ret < 0)
 475                 return ret;
 476
 477         ret = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
 478         if (ret < 0)
 479                 return ret;
 480
 481         /* Disable alarm and timer interrupts */
 482         ret &= ~HYM8563_CTL2_AIE;
 483         ret &= ~HYM8563_CTL2_TIE;
 484
 485         /* Clear any pending alarm and timer flags */
 486         if (ret & HYM8563_CTL2_AF)
 487                 ret &= ~HYM8563_CTL2_AF;
 488
 489         if (ret & HYM8563_CTL2_TF)
 490                 ret &= ~HYM8563_CTL2_TF;
 491
 492         ret &= ~HYM8563_CTL2_TI_TP;
 493
 494         return i2c_smbus_write_byte_data(client, HYM8563_CTL2, ret);
 495 }
 496
 497 #ifdef CONFIG_PM_SLEEP
 498 static int hym8563_suspend(struct device *dev)
 499 {
 500         struct i2c_client *client = to_i2c_client(dev);
 501         int ret;
 502
 503         if (device_may_wakeup(dev)) {
 504                 ret = enable_irq_wake(client->irq);
 505                 if (ret) {
 506                         dev_err(dev, "enable_irq_wake failed, %d\n", ret);
 507                         return ret;
 508                 }
 509         }
 510
 511         return 0;
 512 }
 513
 514 static int hym8563_resume(struct device *dev)
 515 {
 516         struct i2c_client *client = to_i2c_client(dev);
 517
 518         if (device_may_wakeup(dev))
 519                 disable_irq_wake(client->irq);
 520
 521         return 0;
 522 }
 523 #endif
 524
 525 static SIMPLE_DEV_PM_OPS(hym8563_pm_ops, hym8563_suspend, hym8563_resume);
 526
 527 static int hym8563_probe(struct i2c_client *client,
 528                          const struct i2c_device_id *id)
 529 {
 530         struct hym8563 *hym8563;
 531         int ret;
 532
 533         hym8563 = devm_kzalloc(&client->dev, sizeof(*hym8563), GFP_KERNEL);
 534         if (!hym8563)
 535                 return -ENOMEM;
 536
 537         hym8563->client = client;
 538         i2c_set_clientdata(client, hym8563);
 539
 540         device_set_wakeup_capable(&client->dev, true);
 541
 542         ret = hym8563_init_device(client);
 543         if (ret) {
 544                 dev_err(&client->dev, "could not init device, %d\n", ret);
 545                 return ret;
 546         }
 547
 548         if (client->irq > 0) {
 549                 ret = devm_request_threaded_irq(&client->dev, client->irq,
 550                                                 NULL, hym8563_irq,
 551                                                 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 552                                                 client->name, hym8563);
 553                 if (ret < 0) {
 554                         dev_err(&client->dev, "irq %d request failed, %d\n",
 555                                 client->irq, ret);
 556                         return ret;
 557                 }
 558         }
 559
 560         /* check state of calendar information */
 561         ret = i2c_smbus_read_byte_data(client, HYM8563_SEC);
 562         if (ret < 0)
 563                 return ret;
 564
 565         hym8563->valid = !(ret & HYM8563_SEC_VL);
 566         dev_dbg(&client->dev, "rtc information is %s\n",
 567                 hym8563->valid ? "valid" : "invalid");
 568
 569         hym8563->rtc = devm_rtc_device_register(&client->dev, client->name,
 570                                                 &hym8563_rtc_ops, THIS_MODULE);
 571         if (IS_ERR(hym8563->rtc))
 572                 return PTR_ERR(hym8563->rtc);
 573
 574         /* the hym8563 alarm only supports a minute accuracy */
 575         hym8563->rtc->uie_unsupported = 1;
 576
 577 #ifdef CONFIG_COMMON_CLK
 578         hym8563_clkout_register_clk(hym8563);
 579 #endif
 580
 581         return 0;
 582 }
 583
 584 static const struct i2c_device_id hym8563_id[] = {
 585         { "hym8563", 0 },
 586         {},
 587 };
 588 MODULE_DEVICE_TABLE(i2c, hym8563_id);
 589
 590 static const struct of_device_id hym8563_dt_idtable[] = {
 591         { .compatible = "haoyu,hym8563" },
 592         {},
 593 };
 594 MODULE_DEVICE_TABLE(of, hym8563_dt_idtable);
 595
 596 static struct i2c_driver hym8563_driver = {
 597         .driver         = {
 598                 .name   = "rtc-hym8563",
 599                 .pm     = &hym8563_pm_ops,
 600                 .of_match_table = hym8563_dt_idtable,
 601         },
 602         .probe          = hym8563_probe,
 603         .id_table       = hym8563_id,
 604 };
 605
 606 module_i2c_driver(hym8563_driver);
 607
 608 MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
 609 MODULE_DESCRIPTION("HYM8563 RTC driver");
 610 MODULE_LICENSE("GPL");