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         if (ret < 0)
 113                 return ret;
 114
 115         tm->tm_sec = bcd2bin(buf[0] & HYM8563_SEC_MASK);
 116         tm->tm_min = bcd2bin(buf[1] & HYM8563_MIN_MASK);
 117         tm->tm_hour = bcd2bin(buf[2] & HYM8563_HOUR_MASK);
 118         tm->tm_mday = bcd2bin(buf[3] & HYM8563_DAY_MASK);
 119         tm->tm_wday = bcd2bin(buf[4] & HYM8563_WEEKDAY_MASK); /* 0 = Sun */
 120         tm->tm_mon = bcd2bin(buf[5] & HYM8563_MONTH_MASK) - 1; /* 0 = Jan */
 121         tm->tm_year = bcd2bin(buf[6]) + 100;
 122
 123         return 0;
 124 }
 125
 126 static int hym8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
 127 {
 128         struct i2c_client *client = to_i2c_client(dev);
 129         struct hym8563 *hym8563 = i2c_get_clientdata(client);
 130         u8 buf[7];
 131         int ret;
 132
 133         /* Years >= 2100 are to far in the future, 19XX is to early */
 134         if (tm->tm_year < 100 || tm->tm_year >= 200)
 135                 return -EINVAL;
 136
 137         buf[0] = bin2bcd(tm->tm_sec);
 138         buf[1] = bin2bcd(tm->tm_min);
 139         buf[2] = bin2bcd(tm->tm_hour);
 140         buf[3] = bin2bcd(tm->tm_mday);
 141         buf[4] = bin2bcd(tm->tm_wday);
 142         buf[5] = bin2bcd(tm->tm_mon + 1);
 143
 144         /*
 145          * While the HYM8563 has a century flag in the month register,
 146          * it does not seem to carry it over a subsequent write/read.
 147          * So we'll limit ourself to 100 years, starting at 2000 for now.
 148          */
 149         buf[6] = bin2bcd(tm->tm_year - 100);
 150
 151         /*
 152          * CTL1 only contains TEST-mode bits apart from stop,
 153          * so no need to read the value first
 154          */
 155         ret = i2c_smbus_write_byte_data(client, HYM8563_CTL1,
 156                                                 HYM8563_CTL1_STOP);
 157         if (ret < 0)
 158                 return ret;
 159
 160         ret = i2c_smbus_write_i2c_block_data(client, HYM8563_SEC, 7, buf);
 161         if (ret < 0)
 162                 return ret;
 163
 164         ret = i2c_smbus_write_byte_data(client, HYM8563_CTL1, 0);
 165         if (ret < 0)
 166                 return ret;
 167
 168         hym8563->valid = true;
 169
 170         return 0;
 171 }
 172
 173 static int hym8563_rtc_alarm_irq_enable(struct device *dev,
 174                                         unsigned int enabled)
 175 {
 176         struct i2c_client *client = to_i2c_client(dev);
 177         int data;
 178
 179         data = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
 180         if (data < 0)
 181                 return data;
 182
 183         if (enabled)
 184                 data |= HYM8563_CTL2_AIE;
 185         else
 186                 data &= ~HYM8563_CTL2_AIE;
 187
 188         return i2c_smbus_write_byte_data(client, HYM8563_CTL2, data);
 189 };
 190
 191 static int hym8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
 192 {
 193         struct i2c_client *client = to_i2c_client(dev);
 194         struct rtc_time *alm_tm = &alm->time;
 195         u8 buf[4];
 196         int ret;
 197
 198         ret = i2c_smbus_read_i2c_block_data(client, HYM8563_ALM_MIN, 4, buf);
 199         if (ret < 0)
 200                 return ret;
 201
 202         /* The alarm only has a minute accuracy */
 203         alm_tm->tm_sec = 0;
 204
 205         alm_tm->tm_min = (buf[0] & HYM8563_ALM_BIT_DISABLE) ?
 206                                         -1 :
 207                                         bcd2bin(buf[0] & HYM8563_MIN_MASK);
 208         alm_tm->tm_hour = (buf[1] & HYM8563_ALM_BIT_DISABLE) ?
 209                                         -1 :
 210                                         bcd2bin(buf[1] & HYM8563_HOUR_MASK);
 211         alm_tm->tm_mday = (buf[2] & HYM8563_ALM_BIT_DISABLE) ?
 212                                         -1 :
 213                                         bcd2bin(buf[2] & HYM8563_DAY_MASK);
 214         alm_tm->tm_wday = (buf[3] & HYM8563_ALM_BIT_DISABLE) ?
 215                                         -1 :
 216                                         bcd2bin(buf[3] & HYM8563_WEEKDAY_MASK);
 217
 218         ret = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
 219         if (ret < 0)
 220                 return ret;
 221
 222         if (ret & HYM8563_CTL2_AIE)
 223                 alm->enabled = 1;
 224
 225         return 0;
 226 }
 227
 228 static int hym8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 229 {
 230         struct i2c_client *client = to_i2c_client(dev);
 231         struct rtc_time *alm_tm = &alm->time;
 232         u8 buf[4];
 233         int ret;
 234
 235         /*
 236          * The alarm has no seconds so deal with it
 237          */
 238         if (alm_tm->tm_sec) {
 239                 alm_tm->tm_sec = 0;
 240                 alm_tm->tm_min++;
 241                 if (alm_tm->tm_min >= 60) {
 242                         alm_tm->tm_min = 0;
 243                         alm_tm->tm_hour++;
 244                         if (alm_tm->tm_hour >= 24) {
 245                                 alm_tm->tm_hour = 0;
 246                                 alm_tm->tm_mday++;
 247                                 if (alm_tm->tm_mday > 31)
 248                                         alm_tm->tm_mday = 0;
 249                         }
 250                 }
 251         }
 252
 253         ret = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
 254         if (ret < 0)
 255                 return ret;
 256
 257         ret &= ~HYM8563_CTL2_AIE;
 258
 259         ret = i2c_smbus_write_byte_data(client, HYM8563_CTL2, ret);
 260         if (ret < 0)
 261                 return ret;
 262
 263         buf[0] = (alm_tm->tm_min < 60 && alm_tm->tm_min >= 0) ?
 264                         bin2bcd(alm_tm->tm_min) : HYM8563_ALM_BIT_DISABLE;
 265
 266         buf[1] = (alm_tm->tm_hour < 24 && alm_tm->tm_hour >= 0) ?
 267                         bin2bcd(alm_tm->tm_hour) : HYM8563_ALM_BIT_DISABLE;
 268
 269         buf[2] = (alm_tm->tm_mday <= 31 && alm_tm->tm_mday >= 1) ?
 270                         bin2bcd(alm_tm->tm_mday) : HYM8563_ALM_BIT_DISABLE;
 271
 272         buf[3] = (alm_tm->tm_wday < 7 && alm_tm->tm_wday >= 0) ?
 273                         bin2bcd(alm_tm->tm_wday) : HYM8563_ALM_BIT_DISABLE;
 274
 275         ret = i2c_smbus_write_i2c_block_data(client, HYM8563_ALM_MIN, 4, buf);
 276         if (ret < 0)
 277                 return ret;
 278
 279         return hym8563_rtc_alarm_irq_enable(dev, alm->enabled);
 280 }
 281
 282 static const struct rtc_class_ops hym8563_rtc_ops = {
 283         .read_time              = hym8563_rtc_read_time,
 284         .set_time               = hym8563_rtc_set_time,
 285         .alarm_irq_enable       = hym8563_rtc_alarm_irq_enable,
 286         .read_alarm             = hym8563_rtc_read_alarm,
 287         .set_alarm              = hym8563_rtc_set_alarm,
 288 };
 289
 290 /*
 291  * Handling of the clkout
 292  */
 293
 294 #ifdef CONFIG_COMMON_CLK
 295 #define clkout_hw_to_hym8563(_hw) container_of(_hw, struct hym8563, clkout_hw)
 296
 297 static int clkout_rates[] = {
 298         32768,
 299         1024,
 300         32,
 301         1,
 302 };
 303
 304 static unsigned long hym8563_clkout_recalc_rate(struct clk_hw *hw,
 305                                                 unsigned long parent_rate)
 306 {
 307         struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
 308         struct i2c_client *client = hym8563->client;
 309         int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);
 310
 311         if (ret < 0)
 312                 return 0;
 313
 314         ret &= HYM8563_CLKOUT_MASK;
 315         return clkout_rates[ret];
 316 }
 317
 318 static long hym8563_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
 319                                       unsigned long *prate)
 320 {
 321         int i;
 322
 323         for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
 324                 if (clkout_rates[i] <= rate)
 325                         return clkout_rates[i];
 326
 327         return 0;
 328 }
 329
 330 static int hym8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
 331                                    unsigned long parent_rate)
 332 {
 333         struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
 334         struct i2c_client *client = hym8563->client;
 335         int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);
 336         int i;
 337
 338         if (ret < 0)
 339                 return ret;
 340
 341         for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
 342                 if (clkout_rates[i] == rate) {
 343                         ret &= ~HYM8563_CLKOUT_MASK;
 344                         ret |= i;
 345                         return i2c_smbus_write_byte_data(client,
 346                                                          HYM8563_CLKOUT, ret);
 347                 }
 348
 349         return -EINVAL;
 350 }
 351
 352 static int hym8563_clkout_control(struct clk_hw *hw, bool enable)
 353 {
 354         struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
 355         struct i2c_client *client = hym8563->client;
 356         int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);
 357
 358         if (ret < 0)
 359                 return ret;
 360
 361         if (enable)
 362                 ret |= HYM8563_CLKOUT_ENABLE;
 363         else
 364                 ret &= ~HYM8563_CLKOUT_ENABLE;
 365
 366         return i2c_smbus_write_byte_data(client, HYM8563_CLKOUT, ret);
 367 }
 368
 369 static int hym8563_clkout_prepare(struct clk_hw *hw)
 370 {
 371         return hym8563_clkout_control(hw, 1);
 372 }
 373
 374 static void hym8563_clkout_unprepare(struct clk_hw *hw)
 375 {
 376         hym8563_clkout_control(hw, 0);
 377 }
 378
 379 static int hym8563_clkout_is_prepared(struct clk_hw *hw)
 380 {
 381         struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
 382         struct i2c_client *client = hym8563->client;
 383         int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);
 384
 385         if (ret < 0)
 386                 return ret;
 387
 388         return !!(ret & HYM8563_CLKOUT_ENABLE);
 389 }
 390
 391 static const struct clk_ops hym8563_clkout_ops = {
 392         .prepare = hym8563_clkout_prepare,
 393         .unprepare = hym8563_clkout_unprepare,
 394         .is_prepared = hym8563_clkout_is_prepared,
 395         .recalc_rate = hym8563_clkout_recalc_rate,
 396         .round_rate = hym8563_clkout_round_rate,
 397         .set_rate = hym8563_clkout_set_rate,
 398 };
 399
 400 static struct clk *hym8563_clkout_register_clk(struct hym8563 *hym8563)
 401 {
 402         struct i2c_client *client = hym8563->client;
 403         struct device_node *node = client->dev.of_node;
 404         struct clk *clk;
 405         struct clk_init_data init;
 406         int ret;
 407
 408         ret = i2c_smbus_write_byte_data(client, HYM8563_CLKOUT,
 409                                                 0);
 410         if (ret < 0)
 411                 return ERR_PTR(ret);
 412
 413         init.name = "hym8563-clkout";
 414         init.ops = &hym8563_clkout_ops;
 415         init.flags = 0;
 416         init.parent_names = NULL;
 417         init.num_parents = 0;
 418         hym8563->clkout_hw.init = &init;
 419
 420         /* optional override of the clockname */
 421         of_property_read_string(node, "clock-output-names", &init.name);
 422
 423         /* register the clock */
 424         clk = clk_register(&client->dev, &hym8563->clkout_hw);
 425
 426         if (!IS_ERR(clk))
 427                 of_clk_add_provider(node, of_clk_src_simple_get, clk);
 428
 429         return clk;
 430 }
 431 #endif
 432
 433 /*
 434  * The alarm interrupt is implemented as a level-low interrupt in the
 435  * hym8563, while the timer interrupt uses a falling edge.
 436  * We don't use the timer at all, so the interrupt is requested to
 437  * use the level-low trigger.
 438  */
 439 static irqreturn_t hym8563_irq(int irq, void *dev_id)
 440 {
 441         struct hym8563 *hym8563 = (struct hym8563 *)dev_id;
 442         struct i2c_client *client = hym8563->client;
 443         struct mutex *lock = &hym8563->rtc->ops_lock;
 444         int data, ret;
 445
 446         mutex_lock(lock);
 447
 448         /* Clear the alarm flag */
 449
 450         data = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
 451         if (data < 0) {
 452                 dev_err(&client->dev, "%s: error reading i2c data %d\n",
 453                         __func__, data);
 454                 goto out;
 455         }
 456
 457         data &= ~HYM8563_CTL2_AF;
 458
 459         ret = i2c_smbus_write_byte_data(client, HYM8563_CTL2, data);
 460         if (ret < 0) {
 461                 dev_err(&client->dev, "%s: error writing i2c data %d\n",
 462                         __func__, ret);
 463         }
 464
 465 out:
 466         mutex_unlock(lock);
 467         return IRQ_HANDLED;
 468 }
 469
 470 static int hym8563_init_device(struct i2c_client *client)
 471 {
 472         int ret;
 473
 474         /* Clear stop flag if present */
 475         ret = i2c_smbus_write_byte_data(client, HYM8563_CTL1, 0);
 476         if (ret < 0)
 477                 return ret;
 478
 479         ret = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
 480         if (ret < 0)
 481                 return ret;
 482
 483         /* Disable alarm and timer interrupts */
 484         ret &= ~HYM8563_CTL2_AIE;
 485         ret &= ~HYM8563_CTL2_TIE;
 486
 487         /* Clear any pending alarm and timer flags */
 488         if (ret & HYM8563_CTL2_AF)
 489                 ret &= ~HYM8563_CTL2_AF;
 490
 491         if (ret & HYM8563_CTL2_TF)
 492                 ret &= ~HYM8563_CTL2_TF;
 493
 494         ret &= ~HYM8563_CTL2_TI_TP;
 495
 496         return i2c_smbus_write_byte_data(client, HYM8563_CTL2, ret);
 497 }
 498
 499 #ifdef CONFIG_PM_SLEEP
 500 static int hym8563_suspend(struct device *dev)
 501 {
 502         struct i2c_client *client = to_i2c_client(dev);
 503         int ret;
 504
 505         if (device_may_wakeup(dev)) {
 506                 ret = enable_irq_wake(client->irq);
 507                 if (ret) {
 508                         dev_err(dev, "enable_irq_wake failed, %d\n", ret);
 509                         return ret;
 510                 }
 511         }
 512
 513         return 0;
 514 }
 515
 516 static int hym8563_resume(struct device *dev)
 517 {
 518         struct i2c_client *client = to_i2c_client(dev);
 519
 520         if (device_may_wakeup(dev))
 521                 disable_irq_wake(client->irq);
 522
 523         return 0;
 524 }
 525 #endif
 526
 527 static SIMPLE_DEV_PM_OPS(hym8563_pm_ops, hym8563_suspend, hym8563_resume);
 528
 529 static int hym8563_probe(struct i2c_client *client,
 530                          const struct i2c_device_id *id)
 531 {
 532         struct hym8563 *hym8563;
 533         int ret;
 534
 535         hym8563 = devm_kzalloc(&client->dev, sizeof(*hym8563), GFP_KERNEL);
 536         if (!hym8563)
 537                 return -ENOMEM;
 538
 539         hym8563->client = client;
 540         i2c_set_clientdata(client, hym8563);
 541
 542         device_set_wakeup_capable(&client->dev, true);
 543
 544         ret = hym8563_init_device(client);
 545         if (ret) {
 546                 dev_err(&client->dev, "could not init device, %d\n", ret);
 547                 return ret;
 548         }
 549
 550         if (client->irq > 0) {
 551                 ret = devm_request_threaded_irq(&client->dev, client->irq,
 552                                                 NULL, hym8563_irq,
 553                                                 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 554                                                 client->name, hym8563);
 555                 if (ret < 0) {
 556                         dev_err(&client->dev, "irq %d request failed, %d\n",
 557                                 client->irq, ret);
 558                         return ret;
 559                 }
 560         }
 561
 562         /* check state of calendar information */
 563         ret = i2c_smbus_read_byte_data(client, HYM8563_SEC);
 564         if (ret < 0)
 565                 return ret;
 566
 567         hym8563->valid = !(ret & HYM8563_SEC_VL);
 568         dev_dbg(&client->dev, "rtc information is %s\n",
 569                 hym8563->valid ? "valid" : "invalid");
 570
 571         hym8563->rtc = devm_rtc_device_register(&client->dev, client->name,
 572                                                 &hym8563_rtc_ops, THIS_MODULE);
 573         if (IS_ERR(hym8563->rtc))
 574                 return PTR_ERR(hym8563->rtc);
 575
 576         /* the hym8563 alarm only supports a minute accuracy */
 577         hym8563->rtc->uie_unsupported = 1;
 578
 579 #ifdef CONFIG_COMMON_CLK
 580         hym8563_clkout_register_clk(hym8563);
 581 #endif
 582
 583         return 0;
 584 }
 585
 586 static const struct i2c_device_id hym8563_id[] = {
 587         { "hym8563", 0 },
 588         {},
 589 };
 590 MODULE_DEVICE_TABLE(i2c, hym8563_id);
 591
 592 static const struct of_device_id hym8563_dt_idtable[] = {
 593         { .compatible = "haoyu,hym8563" },
 594         {},
 595 };
 596 MODULE_DEVICE_TABLE(of, hym8563_dt_idtable);
 597
 598 static struct i2c_driver hym8563_driver = {
 599         .driver         = {
 600                 .name   = "rtc-hym8563",
 601                 .pm     = &hym8563_pm_ops,
 602                 .of_match_table = hym8563_dt_idtable,
 603         },
 604         .probe          = hym8563_probe,
 605         .id_table       = hym8563_id,
 606 };
 607
 608 module_i2c_driver(hym8563_driver);
 609
 610 MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
 611 MODULE_DESCRIPTION("HYM8563 RTC driver");
 612 MODULE_LICENSE("GPL");