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