drivers/rtc/rtc-hym8563.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Haoyu HYM8563 RTC driver
   4  *
   5  * Copyright (C) 2013 MundoReader S.L.
   6  * Author: Heiko Stuebner <heiko@sntech.de>
   7  *
   8  * based on rtc-HYM8563
   9  * Copyright (C) 2010 ROCKCHIP, Inc.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/clk-provider.h>
  14 #include <linux/i2c.h>
  15 #include <linux/bcd.h>
  16 #include <linux/rtc.h>
  17
  18 #define HYM8563_CTL1            0x00
  19 #define HYM8563_CTL1_TEST       BIT(7)
  20 #define HYM8563_CTL1_STOP       BIT(5)
  21 #define HYM8563_CTL1_TESTC      BIT(3)
  22
  23 #define HYM8563_CTL2            0x01
  24 #define HYM8563_CTL2_TI_TP      BIT(4)
  25 #define HYM8563_CTL2_AF         BIT(3)
  26 #define HYM8563_CTL2_TF         BIT(2)
  27 #define HYM8563_CTL2_AIE        BIT(1)
  28 #define HYM8563_CTL2_TIE        BIT(0)
  29
  30 #define HYM8563_SEC             0x02
  31 #define HYM8563_SEC_VL          BIT(7)
  32 #define HYM8563_SEC_MASK        0x7f
  33
  34 #define HYM8563_MIN             0x03
  35 #define HYM8563_MIN_MASK        0x7f
  36
  37 #define HYM8563_HOUR            0x04
  38 #define HYM8563_HOUR_MASK       0x3f
  39
  40 #define HYM8563_DAY             0x05
  41 #define HYM8563_DAY_MASK        0x3f
  42
  43 #define HYM8563_WEEKDAY         0x06
  44 #define HYM8563_WEEKDAY_MASK    0x07
  45
  46 #define HYM8563_MONTH           0x07
  47 #define HYM8563_MONTH_CENTURY   BIT(7)
  48 #define HYM8563_MONTH_MASK      0x1f
  49
  50 #define HYM8563_YEAR            0x08
  51
  52 #define HYM8563_ALM_MIN         0x09
  53 #define HYM8563_ALM_HOUR        0x0a
  54 #define HYM8563_ALM_DAY         0x0b
  55 #define HYM8563_ALM_WEEK        0x0c
  56
  57 /* Each alarm check can be disabled by setting this bit in the register */
  58 #define HYM8563_ALM_BIT_DISABLE BIT(7)
  59
  60 #define HYM8563_CLKOUT          0x0d
  61 #define HYM8563_CLKOUT_ENABLE   BIT(7)
  62 #define HYM8563_CLKOUT_32768    0
  63 #define HYM8563_CLKOUT_1024     1
  64 #define HYM8563_CLKOUT_32       2
  65 #define HYM8563_CLKOUT_1        3
  66 #define HYM8563_CLKOUT_MASK     3
  67
  68 #define HYM8563_TMR_CTL         0x0e
  69 #define HYM8563_TMR_CTL_ENABLE  BIT(7)
  70 #define HYM8563_TMR_CTL_4096    0
  71 #define HYM8563_TMR_CTL_64      1
  72 #define HYM8563_TMR_CTL_1       2
  73 #define HYM8563_TMR_CTL_1_60    3
  74 #define HYM8563_TMR_CTL_MASK    3
  75
  76 #define HYM8563_TMR_CNT         0x0f
  77
  78 struct hym8563 {
  79         struct i2c_client       *client;
  80         struct rtc_device       *rtc;
  81 #ifdef CONFIG_COMMON_CLK
  82         struct clk_hw           clkout_hw;
  83 #endif
  84 };
  85
  86 /*
  87  * RTC handling
  88  */
  89
  90 static int hym8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
  91 {
  92         struct i2c_client *client = to_i2c_client(dev);
  93         u8 buf[7];
  94         int ret;
  95
  96         ret = i2c_smbus_read_i2c_block_data(client, HYM8563_SEC, 7, buf);
  97         if (ret < 0)
  98                 return ret;
  99
 100         if (buf[0] & HYM8563_SEC_VL) {
 101                 dev_warn(&client->dev,
 102                          "no valid clock/calendar values available\n");
 103                 return -EINVAL;
 104         }
 105
 106         tm->tm_sec = bcd2bin(buf[0] & HYM8563_SEC_MASK);
 107         tm->tm_min = bcd2bin(buf[1] & HYM8563_MIN_MASK);
 108         tm->tm_hour = bcd2bin(buf[2] & HYM8563_HOUR_MASK);
 109         tm->tm_mday = bcd2bin(buf[3] & HYM8563_DAY_MASK);
 110         tm->tm_wday = bcd2bin(buf[4] & HYM8563_WEEKDAY_MASK); /* 0 = Sun */
 111         tm->tm_mon = bcd2bin(buf[5] & HYM8563_MONTH_MASK) - 1; /* 0 = Jan */
 112         tm->tm_year = bcd2bin(buf[6]) + 100;
 113
 114         return 0;
 115 }
 116
 117 static int hym8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
 118 {
 119         struct i2c_client *client = to_i2c_client(dev);
 120         u8 buf[7];
 121         int ret;
 122
 123         /* Years >= 2100 are to far in the future, 19XX is to early */
 124         if (tm->tm_year < 100 || tm->tm_year >= 200)
 125                 return -EINVAL;
 126
 127         buf[0] = bin2bcd(tm->tm_sec);
 128         buf[1] = bin2bcd(tm->tm_min);
 129         buf[2] = bin2bcd(tm->tm_hour);
 130         buf[3] = bin2bcd(tm->tm_mday);
 131         buf[4] = bin2bcd(tm->tm_wday);
 132         buf[5] = bin2bcd(tm->tm_mon + 1);
 133
 134         /*
 135          * While the HYM8563 has a century flag in the month register,
 136          * it does not seem to carry it over a subsequent write/read.
 137          * So we'll limit ourself to 100 years, starting at 2000 for now.
 138          */
 139         buf[6] = bin2bcd(tm->tm_year - 100);
 140
 141         /*
 142          * CTL1 only contains TEST-mode bits apart from stop,
 143          * so no need to read the value first
 144          */
 145         ret = i2c_smbus_write_byte_data(client, HYM8563_CTL1,
 146                                                 HYM8563_CTL1_STOP);
 147         if (ret < 0)
 148                 return ret;
 149
 150         ret = i2c_smbus_write_i2c_block_data(client, HYM8563_SEC, 7, buf);
 151         if (ret < 0)
 152                 return ret;
 153
 154         ret = i2c_smbus_write_byte_data(client, HYM8563_CTL1, 0);
 155         if (ret < 0)
 156                 return ret;
 157
 158         return 0;
 159 }
 160
 161 static int hym8563_rtc_alarm_irq_enable(struct device *dev,
 162                                         unsigned int enabled)
 163 {
 164         struct i2c_client *client = to_i2c_client(dev);
 165         int data;
 166
 167         data = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
 168         if (data < 0)
 169                 return data;
 170
 171         if (enabled)
 172                 data |= HYM8563_CTL2_AIE;
 173         else
 174                 data &= ~HYM8563_CTL2_AIE;
 175
 176         return i2c_smbus_write_byte_data(client, HYM8563_CTL2, data);
 177 };
 178
 179 static int hym8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
 180 {
 181         struct i2c_client *client = to_i2c_client(dev);
 182         struct rtc_time *alm_tm = &alm->time;
 183         u8 buf[4];
 184         int ret;
 185
 186         ret = i2c_smbus_read_i2c_block_data(client, HYM8563_ALM_MIN, 4, buf);
 187         if (ret < 0)
 188                 return ret;
 189
 190         /* The alarm only has a minute accuracy */
 191         alm_tm->tm_sec = 0;
 192
 193         alm_tm->tm_min = (buf[0] & HYM8563_ALM_BIT_DISABLE) ?
 194                                         -1 :
 195                                         bcd2bin(buf[0] & HYM8563_MIN_MASK);
 196         alm_tm->tm_hour = (buf[1] & HYM8563_ALM_BIT_DISABLE) ?
 197                                         -1 :
 198                                         bcd2bin(buf[1] & HYM8563_HOUR_MASK);
 199         alm_tm->tm_mday = (buf[2] & HYM8563_ALM_BIT_DISABLE) ?
 200                                         -1 :
 201                                         bcd2bin(buf[2] & HYM8563_DAY_MASK);
 202         alm_tm->tm_wday = (buf[3] & HYM8563_ALM_BIT_DISABLE) ?
 203                                         -1 :
 204                                         bcd2bin(buf[3] & HYM8563_WEEKDAY_MASK);
 205
 206         ret = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
 207         if (ret < 0)
 208                 return ret;
 209
 210         if (ret & HYM8563_CTL2_AIE)
 211                 alm->enabled = 1;
 212
 213         return 0;
 214 }
 215
 216 static int hym8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 217 {
 218         struct i2c_client *client = to_i2c_client(dev);
 219         struct rtc_time *alm_tm = &alm->time;
 220         u8 buf[4];
 221         int ret;
 222
 223         ret = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
 224         if (ret < 0)
 225                 return ret;
 226
 227         ret &= ~HYM8563_CTL2_AIE;
 228
 229         ret = i2c_smbus_write_byte_data(client, HYM8563_CTL2, ret);
 230         if (ret < 0)
 231                 return ret;
 232
 233         buf[0] = (alm_tm->tm_min < 60 && alm_tm->tm_min >= 0) ?
 234                         bin2bcd(alm_tm->tm_min) : HYM8563_ALM_BIT_DISABLE;
 235
 236         buf[1] = (alm_tm->tm_hour < 24 && alm_tm->tm_hour >= 0) ?
 237                         bin2bcd(alm_tm->tm_hour) : HYM8563_ALM_BIT_DISABLE;
 238
 239         buf[2] = (alm_tm->tm_mday <= 31 && alm_tm->tm_mday >= 1) ?
 240                         bin2bcd(alm_tm->tm_mday) : HYM8563_ALM_BIT_DISABLE;
 241
 242         buf[3] = (alm_tm->tm_wday < 7 && alm_tm->tm_wday >= 0) ?
 243                         bin2bcd(alm_tm->tm_wday) : HYM8563_ALM_BIT_DISABLE;
 244
 245         ret = i2c_smbus_write_i2c_block_data(client, HYM8563_ALM_MIN, 4, buf);
 246         if (ret < 0)
 247                 return ret;
 248
 249         return hym8563_rtc_alarm_irq_enable(dev, alm->enabled);
 250 }
 251
 252 static const struct rtc_class_ops hym8563_rtc_ops = {
 253         .read_time              = hym8563_rtc_read_time,
 254         .set_time               = hym8563_rtc_set_time,
 255         .alarm_irq_enable       = hym8563_rtc_alarm_irq_enable,
 256         .read_alarm             = hym8563_rtc_read_alarm,
 257         .set_alarm              = hym8563_rtc_set_alarm,
 258 };
 259
 260 /*
 261  * Handling of the clkout
 262  */
 263
 264 #ifdef CONFIG_COMMON_CLK
 265 #define clkout_hw_to_hym8563(_hw) container_of(_hw, struct hym8563, clkout_hw)
 266
 267 static int clkout_rates[] = {
 268         32768,
 269         1024,
 270         32,
 271         1,
 272 };
 273
 274 static unsigned long hym8563_clkout_recalc_rate(struct clk_hw *hw,
 275                                                 unsigned long parent_rate)
 276 {
 277         struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
 278         struct i2c_client *client = hym8563->client;
 279         int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);
 280
 281         if (ret < 0)
 282                 return 0;
 283
 284         ret &= HYM8563_CLKOUT_MASK;
 285         return clkout_rates[ret];
 286 }
 287
 288 static long hym8563_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
 289                                       unsigned long *prate)
 290 {
 291         int i;
 292
 293         for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
 294                 if (clkout_rates[i] <= rate)
 295                         return clkout_rates[i];
 296
 297         return 0;
 298 }
 299
 300 static int hym8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
 301                                    unsigned long parent_rate)
 302 {
 303         struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
 304         struct i2c_client *client = hym8563->client;
 305         int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);
 306         int i;
 307
 308         if (ret < 0)
 309                 return ret;
 310
 311         for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
 312                 if (clkout_rates[i] == rate) {
 313                         ret &= ~HYM8563_CLKOUT_MASK;
 314                         ret |= i;
 315                         return i2c_smbus_write_byte_data(client,
 316                                                          HYM8563_CLKOUT, ret);
 317                 }
 318
 319         return -EINVAL;
 320 }
 321
 322 static int hym8563_clkout_control(struct clk_hw *hw, bool enable)
 323 {
 324         struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
 325         struct i2c_client *client = hym8563->client;
 326         int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);
 327
 328         if (ret < 0)
 329                 return ret;
 330
 331         if (enable)
 332                 ret |= HYM8563_CLKOUT_ENABLE;
 333         else
 334                 ret &= ~HYM8563_CLKOUT_ENABLE;
 335
 336         return i2c_smbus_write_byte_data(client, HYM8563_CLKOUT, ret);
 337 }
 338
 339 static int hym8563_clkout_prepare(struct clk_hw *hw)
 340 {
 341         return hym8563_clkout_control(hw, 1);
 342 }
 343
 344 static void hym8563_clkout_unprepare(struct clk_hw *hw)
 345 {
 346         hym8563_clkout_control(hw, 0);
 347 }
 348
 349 static int hym8563_clkout_is_prepared(struct clk_hw *hw)
 350 {
 351         struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
 352         struct i2c_client *client = hym8563->client;
 353         int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);
 354
 355         if (ret < 0)
 356                 return ret;
 357
 358         return !!(ret & HYM8563_CLKOUT_ENABLE);
 359 }
 360
 361 static const struct clk_ops hym8563_clkout_ops = {
 362         .prepare = hym8563_clkout_prepare,
 363         .unprepare = hym8563_clkout_unprepare,
 364         .is_prepared = hym8563_clkout_is_prepared,
 365         .recalc_rate = hym8563_clkout_recalc_rate,
 366         .round_rate = hym8563_clkout_round_rate,
 367         .set_rate = hym8563_clkout_set_rate,
 368 };
 369
 370 static struct clk *hym8563_clkout_register_clk(struct hym8563 *hym8563)
 371 {
 372         struct i2c_client *client = hym8563->client;
 373         struct device_node *node = client->dev.of_node;
 374         struct clk *clk;
 375         struct clk_init_data init;
 376         int ret;
 377
 378         ret = i2c_smbus_write_byte_data(client, HYM8563_CLKOUT,
 379                                                 0);
 380         if (ret < 0)
 381                 return ERR_PTR(ret);
 382
 383         init.name = "hym8563-clkout";
 384         init.ops = &hym8563_clkout_ops;
 385         init.flags = 0;
 386         init.parent_names = NULL;
 387         init.num_parents = 0;
 388         hym8563->clkout_hw.init = &init;
 389
 390         /* optional override of the clockname */
 391         of_property_read_string(node, "clock-output-names", &init.name);
 392
 393         /* register the clock */
 394         clk = clk_register(&client->dev, &hym8563->clkout_hw);
 395
 396         if (!IS_ERR(clk))
 397                 of_clk_add_provider(node, of_clk_src_simple_get, clk);
 398
 399         return clk;
 400 }
 401 #endif
 402
 403 /*
 404  * The alarm interrupt is implemented as a level-low interrupt in the
 405  * hym8563, while the timer interrupt uses a falling edge.
 406  * We don't use the timer at all, so the interrupt is requested to
 407  * use the level-low trigger.
 408  */
 409 static irqreturn_t hym8563_irq(int irq, void *dev_id)
 410 {
 411         struct hym8563 *hym8563 = (struct hym8563 *)dev_id;
 412         struct i2c_client *client = hym8563->client;
 413         int data, ret;
 414
 415         rtc_lock(hym8563->rtc);
 416
 417         /* Clear the alarm flag */
 418
 419         data = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
 420         if (data < 0) {
 421                 dev_err(&client->dev, "%s: error reading i2c data %d\n",
 422                         __func__, data);
 423                 goto out;
 424         }
 425
 426         data &= ~HYM8563_CTL2_AF;
 427
 428         ret = i2c_smbus_write_byte_data(client, HYM8563_CTL2, data);
 429         if (ret < 0) {
 430                 dev_err(&client->dev, "%s: error writing i2c data %d\n",
 431                         __func__, ret);
 432         }
 433
 434 out:
 435         rtc_unlock(hym8563->rtc);
 436         return IRQ_HANDLED;
 437 }
 438
 439 static int hym8563_init_device(struct i2c_client *client)
 440 {
 441         int ret;
 442
 443         /* Clear stop flag if present */
 444         ret = i2c_smbus_write_byte_data(client, HYM8563_CTL1, 0);
 445         if (ret < 0)
 446                 return ret;
 447
 448         ret = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
 449         if (ret < 0)
 450                 return ret;
 451
 452         /* Disable alarm and timer interrupts */
 453         ret &= ~HYM8563_CTL2_AIE;
 454         ret &= ~HYM8563_CTL2_TIE;
 455
 456         /* Clear any pending alarm and timer flags */
 457         if (ret & HYM8563_CTL2_AF)
 458                 ret &= ~HYM8563_CTL2_AF;
 459
 460         if (ret & HYM8563_CTL2_TF)
 461                 ret &= ~HYM8563_CTL2_TF;
 462
 463         ret &= ~HYM8563_CTL2_TI_TP;
 464
 465         return i2c_smbus_write_byte_data(client, HYM8563_CTL2, ret);
 466 }
 467
 468 #ifdef CONFIG_PM_SLEEP
 469 static int hym8563_suspend(struct device *dev)
 470 {
 471         struct i2c_client *client = to_i2c_client(dev);
 472         int ret;
 473
 474         if (device_may_wakeup(dev)) {
 475                 ret = enable_irq_wake(client->irq);
 476                 if (ret) {
 477                         dev_err(dev, "enable_irq_wake failed, %d\n", ret);
 478                         return ret;
 479                 }
 480         }
 481
 482         return 0;
 483 }
 484
 485 static int hym8563_resume(struct device *dev)
 486 {
 487         struct i2c_client *client = to_i2c_client(dev);
 488
 489         if (device_may_wakeup(dev))
 490                 disable_irq_wake(client->irq);
 491
 492         return 0;
 493 }
 494 #endif
 495
 496 static SIMPLE_DEV_PM_OPS(hym8563_pm_ops, hym8563_suspend, hym8563_resume);
 497
 498 static int hym8563_probe(struct i2c_client *client)
 499 {
 500         struct hym8563 *hym8563;
 501         int ret;
 502
 503         hym8563 = devm_kzalloc(&client->dev, sizeof(*hym8563), GFP_KERNEL);
 504         if (!hym8563)
 505                 return -ENOMEM;
 506
 507         hym8563->rtc = devm_rtc_allocate_device(&client->dev);
 508         if (IS_ERR(hym8563->rtc))
 509                 return PTR_ERR(hym8563->rtc);
 510
 511         hym8563->client = client;
 512         i2c_set_clientdata(client, hym8563);
 513
 514         ret = hym8563_init_device(client);
 515         if (ret) {
 516                 dev_err(&client->dev, "could not init device, %d\n", ret);
 517                 return ret;
 518         }
 519
 520         if (client->irq > 0) {
 521                 ret = devm_request_threaded_irq(&client->dev, client->irq,
 522                                                 NULL, hym8563_irq,
 523                                                 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 524                                                 client->name, hym8563);
 525                 if (ret < 0) {
 526                         dev_err(&client->dev, "irq %d request failed, %d\n",
 527                                 client->irq, ret);
 528                         return ret;
 529                 }
 530         }
 531
 532         if (client->irq > 0 ||
 533             device_property_read_bool(&client->dev, "wakeup-source")) {
 534                 device_init_wakeup(&client->dev, true);
 535         }
 536
 537         /* check state of calendar information */
 538         ret = i2c_smbus_read_byte_data(client, HYM8563_SEC);
 539         if (ret < 0)
 540                 return ret;
 541
 542         dev_dbg(&client->dev, "rtc information is %s\n",
 543                 (ret & HYM8563_SEC_VL) ? "invalid" : "valid");
 544
 545         hym8563->rtc->ops = &hym8563_rtc_ops;
 546         set_bit(RTC_FEATURE_ALARM_RES_MINUTE, hym8563->rtc->features);
 547         clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, hym8563->rtc->features);
 548
 549 #ifdef CONFIG_COMMON_CLK
 550         hym8563_clkout_register_clk(hym8563);
 551 #endif
 552
 553         return devm_rtc_register_device(hym8563->rtc);
 554 }
 555
 556 static const struct i2c_device_id hym8563_id[] = {
 557         { "hym8563", 0 },
 558         {},
 559 };
 560 MODULE_DEVICE_TABLE(i2c, hym8563_id);
 561
 562 static const struct of_device_id hym8563_dt_idtable[] = {
 563         { .compatible = "haoyu,hym8563" },
 564         {},
 565 };
 566 MODULE_DEVICE_TABLE(of, hym8563_dt_idtable);
 567
 568 static struct i2c_driver hym8563_driver = {
 569         .driver         = {
 570                 .name   = "rtc-hym8563",
 571                 .pm     = &hym8563_pm_ops,
 572                 .of_match_table = hym8563_dt_idtable,
 573         },
 574         .probe_new      = hym8563_probe,
 575         .id_table       = hym8563_id,
 576 };
 577
 578 module_i2c_driver(hym8563_driver);
 579
 580 MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
 581 MODULE_DESCRIPTION("HYM8563 RTC driver");
 582 MODULE_LICENSE("GPL");