drivers/rtc/rtc-ac100.c

   1 /*
   2  * RTC Driver for X-Powers AC100
   3  *
   4  * Copyright (c) 2016 Chen-Yu Tsai
   5  *
   6  * Chen-Yu Tsai <wens@csie.org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but WITHOUT
  13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  15  * more details.
  16  */
  17
  18 #include <linux/bcd.h>
  19 #include <linux/clk-provider.h>
  20 #include <linux/device.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/kernel.h>
  23 #include <linux/mfd/ac100.h>
  24 #include <linux/module.h>
  25 #include <linux/mutex.h>
  26 #include <linux/of.h>
  27 #include <linux/platform_device.h>
  28 #include <linux/regmap.h>
  29 #include <linux/rtc.h>
  30 #include <linux/types.h>
  31
  32 /* Control register */
  33 #define AC100_RTC_CTRL_24HOUR   BIT(0)
  34
  35 /* Clock output register bits */
  36 #define AC100_CLKOUT_PRE_DIV_SHIFT      5
  37 #define AC100_CLKOUT_PRE_DIV_WIDTH      3
  38 #define AC100_CLKOUT_MUX_SHIFT          4
  39 #define AC100_CLKOUT_MUX_WIDTH          1
  40 #define AC100_CLKOUT_DIV_SHIFT          1
  41 #define AC100_CLKOUT_DIV_WIDTH          3
  42 #define AC100_CLKOUT_EN                 BIT(0)
  43
  44 /* RTC */
  45 #define AC100_RTC_SEC_MASK      GENMASK(6, 0)
  46 #define AC100_RTC_MIN_MASK      GENMASK(6, 0)
  47 #define AC100_RTC_HOU_MASK      GENMASK(5, 0)
  48 #define AC100_RTC_WEE_MASK      GENMASK(2, 0)
  49 #define AC100_RTC_DAY_MASK      GENMASK(5, 0)
  50 #define AC100_RTC_MON_MASK      GENMASK(4, 0)
  51 #define AC100_RTC_YEA_MASK      GENMASK(7, 0)
  52 #define AC100_RTC_YEA_LEAP      BIT(15)
  53 #define AC100_RTC_UPD_TRIGGER   BIT(15)
  54
  55 /* Alarm (wall clock) */
  56 #define AC100_ALM_INT_ENABLE    BIT(0)
  57
  58 #define AC100_ALM_SEC_MASK      GENMASK(6, 0)
  59 #define AC100_ALM_MIN_MASK      GENMASK(6, 0)
  60 #define AC100_ALM_HOU_MASK      GENMASK(5, 0)
  61 #define AC100_ALM_WEE_MASK      GENMASK(2, 0)
  62 #define AC100_ALM_DAY_MASK      GENMASK(5, 0)
  63 #define AC100_ALM_MON_MASK      GENMASK(4, 0)
  64 #define AC100_ALM_YEA_MASK      GENMASK(7, 0)
  65 #define AC100_ALM_ENABLE_FLAG   BIT(15)
  66 #define AC100_ALM_UPD_TRIGGER   BIT(15)
  67
  68 /*
  69  * The year parameter passed to the driver is usually an offset relative to
  70  * the year 1900. This macro is used to convert this offset to another one
  71  * relative to the minimum year allowed by the hardware.
  72  *
  73  * The year range is 1970 - 2069. This range is selected to match Allwinner's
  74  * driver.
  75  */
  76 #define AC100_YEAR_MIN                          1970
  77 #define AC100_YEAR_MAX                          2069
  78 #define AC100_YEAR_OFF                          (AC100_YEAR_MIN - 1900)
  79
  80 struct ac100_clkout {
  81         struct clk_hw hw;
  82         struct regmap *regmap;
  83         u8 offset;
  84 };
  85
  86 #define to_ac100_clkout(_hw) container_of(_hw, struct ac100_clkout, hw)
  87
  88 #define AC100_RTC_32K_NAME      "ac100-rtc-32k"
  89 #define AC100_RTC_32K_RATE      32768
  90 #define AC100_CLKOUT_NUM        3
  91
  92 static const char * const ac100_clkout_names[AC100_CLKOUT_NUM] = {
  93         "ac100-cko1-rtc",
  94         "ac100-cko2-rtc",
  95         "ac100-cko3-rtc",
  96 };
  97
  98 struct ac100_rtc_dev {
  99         struct rtc_device *rtc;
 100         struct device *dev;
 101         struct regmap *regmap;
 102         int irq;
 103         unsigned long alarm;
 104
 105         struct clk_hw *rtc_32k_clk;
 106         struct ac100_clkout clks[AC100_CLKOUT_NUM];
 107         struct clk_hw_onecell_data *clk_data;
 108 };
 109
 110 /**
 111  * Clock controls for 3 clock output pins
 112  */
 113
 114 static const struct clk_div_table ac100_clkout_prediv[] = {
 115         { .val = 0, .div = 1 },
 116         { .val = 1, .div = 2 },
 117         { .val = 2, .div = 4 },
 118         { .val = 3, .div = 8 },
 119         { .val = 4, .div = 16 },
 120         { .val = 5, .div = 32 },
 121         { .val = 6, .div = 64 },
 122         { .val = 7, .div = 122 },
 123         { },
 124 };
 125
 126 /* Abuse the fact that one parent is 32768 Hz, and the other is 4 MHz */
 127 static unsigned long ac100_clkout_recalc_rate(struct clk_hw *hw,
 128                                               unsigned long prate)
 129 {
 130         struct ac100_clkout *clk = to_ac100_clkout(hw);
 131         unsigned int reg, div;
 132
 133         regmap_read(clk->regmap, clk->offset, &reg);
 134
 135         /* Handle pre-divider first */
 136         if (prate != AC100_RTC_32K_RATE) {
 137                 div = (reg >> AC100_CLKOUT_PRE_DIV_SHIFT) &
 138                         ((1 << AC100_CLKOUT_PRE_DIV_WIDTH) - 1);
 139                 prate = divider_recalc_rate(hw, prate, div,
 140                                             ac100_clkout_prediv, 0,
 141                                             AC100_CLKOUT_PRE_DIV_WIDTH);
 142         }
 143
 144         div = (reg >> AC100_CLKOUT_DIV_SHIFT) &
 145                 (BIT(AC100_CLKOUT_DIV_WIDTH) - 1);
 146         return divider_recalc_rate(hw, prate, div, NULL,
 147                                    CLK_DIVIDER_POWER_OF_TWO,
 148                                    AC100_CLKOUT_DIV_WIDTH);
 149 }
 150
 151 static long ac100_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
 152                                     unsigned long prate)
 153 {
 154         unsigned long best_rate = 0, tmp_rate, tmp_prate;
 155         int i;
 156
 157         if (prate == AC100_RTC_32K_RATE)
 158                 return divider_round_rate(hw, rate, &prate, NULL,
 159                                           AC100_CLKOUT_DIV_WIDTH,
 160                                           CLK_DIVIDER_POWER_OF_TWO);
 161
 162         for (i = 0; ac100_clkout_prediv[i].div; i++) {
 163                 tmp_prate = DIV_ROUND_UP(prate, ac100_clkout_prediv[i].val);
 164                 tmp_rate = divider_round_rate(hw, rate, &tmp_prate, NULL,
 165                                               AC100_CLKOUT_DIV_WIDTH,
 166                                               CLK_DIVIDER_POWER_OF_TWO);
 167
 168                 if (tmp_rate > rate)
 169                         continue;
 170                 if (rate - tmp_rate < best_rate - tmp_rate)
 171                         best_rate = tmp_rate;
 172         }
 173
 174         return best_rate;
 175 }
 176
 177 static int ac100_clkout_determine_rate(struct clk_hw *hw,
 178                                        struct clk_rate_request *req)
 179 {
 180         struct clk_hw *best_parent;
 181         unsigned long best = 0;
 182         int i, num_parents = clk_hw_get_num_parents(hw);
 183
 184         for (i = 0; i < num_parents; i++) {
 185                 struct clk_hw *parent = clk_hw_get_parent_by_index(hw, i);
 186                 unsigned long tmp, prate = clk_hw_get_rate(parent);
 187
 188                 tmp = ac100_clkout_round_rate(hw, req->rate, prate);
 189
 190                 if (tmp > req->rate)
 191                         continue;
 192                 if (req->rate - tmp < req->rate - best) {
 193                         best = tmp;
 194                         best_parent = parent;
 195                 }
 196         }
 197
 198         if (!best)
 199                 return -EINVAL;
 200
 201         req->best_parent_hw = best_parent;
 202         req->best_parent_rate = best;
 203         req->rate = best;
 204
 205         return 0;
 206 }
 207
 208 static int ac100_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
 209                                  unsigned long prate)
 210 {
 211         struct ac100_clkout *clk = to_ac100_clkout(hw);
 212         int div = 0, pre_div = 0;
 213
 214         do {
 215                 div = divider_get_val(rate * ac100_clkout_prediv[pre_div].div,
 216                                       prate, NULL, AC100_CLKOUT_DIV_WIDTH,
 217                                       CLK_DIVIDER_POWER_OF_TWO);
 218                 if (div >= 0)
 219                         break;
 220         } while (prate != AC100_RTC_32K_RATE &&
 221                  ac100_clkout_prediv[++pre_div].div);
 222
 223         if (div < 0)
 224                 return div;
 225
 226         pre_div = ac100_clkout_prediv[pre_div].val;
 227
 228         regmap_update_bits(clk->regmap, clk->offset,
 229                            ((1 << AC100_CLKOUT_DIV_WIDTH) - 1) << AC100_CLKOUT_DIV_SHIFT |
 230                            ((1 << AC100_CLKOUT_PRE_DIV_WIDTH) - 1) << AC100_CLKOUT_PRE_DIV_SHIFT,
 231                            (div - 1) << AC100_CLKOUT_DIV_SHIFT |
 232                            (pre_div - 1) << AC100_CLKOUT_PRE_DIV_SHIFT);
 233
 234         return 0;
 235 }
 236
 237 static int ac100_clkout_prepare(struct clk_hw *hw)
 238 {
 239         struct ac100_clkout *clk = to_ac100_clkout(hw);
 240
 241         return regmap_update_bits(clk->regmap, clk->offset, AC100_CLKOUT_EN,
 242                                   AC100_CLKOUT_EN);
 243 }
 244
 245 static void ac100_clkout_unprepare(struct clk_hw *hw)
 246 {
 247         struct ac100_clkout *clk = to_ac100_clkout(hw);
 248
 249         regmap_update_bits(clk->regmap, clk->offset, AC100_CLKOUT_EN, 0);
 250 }
 251
 252 static int ac100_clkout_is_prepared(struct clk_hw *hw)
 253 {
 254         struct ac100_clkout *clk = to_ac100_clkout(hw);
 255         unsigned int reg;
 256
 257         regmap_read(clk->regmap, clk->offset, &reg);
 258
 259         return reg & AC100_CLKOUT_EN;
 260 }
 261
 262 static u8 ac100_clkout_get_parent(struct clk_hw *hw)
 263 {
 264         struct ac100_clkout *clk = to_ac100_clkout(hw);
 265         unsigned int reg;
 266
 267         regmap_read(clk->regmap, clk->offset, &reg);
 268
 269         return (reg >> AC100_CLKOUT_MUX_SHIFT) & 0x1;
 270 }
 271
 272 static int ac100_clkout_set_parent(struct clk_hw *hw, u8 index)
 273 {
 274         struct ac100_clkout *clk = to_ac100_clkout(hw);
 275
 276         return regmap_update_bits(clk->regmap, clk->offset,
 277                                   BIT(AC100_CLKOUT_MUX_SHIFT),
 278                                   index ? BIT(AC100_CLKOUT_MUX_SHIFT) : 0);
 279 }
 280
 281 static const struct clk_ops ac100_clkout_ops = {
 282         .prepare        = ac100_clkout_prepare,
 283         .unprepare      = ac100_clkout_unprepare,
 284         .is_prepared    = ac100_clkout_is_prepared,
 285         .recalc_rate    = ac100_clkout_recalc_rate,
 286         .determine_rate = ac100_clkout_determine_rate,
 287         .get_parent     = ac100_clkout_get_parent,
 288         .set_parent     = ac100_clkout_set_parent,
 289         .set_rate       = ac100_clkout_set_rate,
 290 };
 291
 292 static int ac100_rtc_register_clks(struct ac100_rtc_dev *chip)
 293 {
 294         struct device_node *np = chip->dev->of_node;
 295         const char *parents[2] = {AC100_RTC_32K_NAME};
 296         int i, ret;
 297
 298         chip->clk_data = devm_kzalloc(chip->dev, sizeof(*chip->clk_data) +
 299                                                  sizeof(*chip->clk_data->hws) *
 300                                                  AC100_CLKOUT_NUM,
 301                                                  GFP_KERNEL);
 302         if (!chip->clk_data)
 303                 return -ENOMEM;
 304
 305         chip->rtc_32k_clk = clk_hw_register_fixed_rate(chip->dev,
 306                                                        AC100_RTC_32K_NAME,
 307                                                        NULL, 0,
 308                                                        AC100_RTC_32K_RATE);
 309         if (IS_ERR(chip->rtc_32k_clk)) {
 310                 ret = PTR_ERR(chip->rtc_32k_clk);
 311                 dev_err(chip->dev, "Failed to register RTC-32k clock: %d\n",
 312                         ret);
 313                 return ret;
 314         }
 315
 316         parents[1] = of_clk_get_parent_name(np, 0);
 317         if (!parents[1]) {
 318                 dev_err(chip->dev, "Failed to get ADDA 4M clock\n");
 319                 return -EINVAL;
 320         }
 321
 322         for (i = 0; i < AC100_CLKOUT_NUM; i++) {
 323                 struct ac100_clkout *clk = &chip->clks[i];
 324                 struct clk_init_data init = {
 325                         .name = ac100_clkout_names[i],
 326                         .ops = &ac100_clkout_ops,
 327                         .parent_names = parents,
 328                         .num_parents = ARRAY_SIZE(parents),
 329                         .flags = 0,
 330                 };
 331
 332                 of_property_read_string_index(np, "clock-output-names",
 333                                               i, &init.name);
 334                 clk->regmap = chip->regmap;
 335                 clk->offset = AC100_CLKOUT_CTRL1 + i;
 336                 clk->hw.init = &init;
 337
 338                 ret = devm_clk_hw_register(chip->dev, &clk->hw);
 339                 if (ret) {
 340                         dev_err(chip->dev, "Failed to register clk '%s': %d\n",
 341                                 init.name, ret);
 342                         goto err_unregister_rtc_32k;
 343                 }
 344
 345                 chip->clk_data->hws[i] = &clk->hw;
 346         }
 347
 348         chip->clk_data->num = i;
 349         ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, chip->clk_data);
 350         if (ret)
 351                 goto err_unregister_rtc_32k;
 352
 353         return 0;
 354
 355 err_unregister_rtc_32k:
 356         clk_unregister_fixed_rate(chip->rtc_32k_clk->clk);
 357
 358         return ret;
 359 }
 360
 361 static void ac100_rtc_unregister_clks(struct ac100_rtc_dev *chip)
 362 {
 363         of_clk_del_provider(chip->dev->of_node);
 364         clk_unregister_fixed_rate(chip->rtc_32k_clk->clk);
 365 }
 366
 367 /**
 368  * RTC related bits
 369  */
 370 static int ac100_rtc_get_time(struct device *dev, struct rtc_time *rtc_tm)
 371 {
 372         struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
 373         struct regmap *regmap = chip->regmap;
 374         u16 reg[7];
 375         int ret;
 376
 377         ret = regmap_bulk_read(regmap, AC100_RTC_SEC, reg, 7);
 378         if (ret)
 379                 return ret;
 380
 381         rtc_tm->tm_sec  = bcd2bin(reg[0] & AC100_RTC_SEC_MASK);
 382         rtc_tm->tm_min  = bcd2bin(reg[1] & AC100_RTC_MIN_MASK);
 383         rtc_tm->tm_hour = bcd2bin(reg[2] & AC100_RTC_HOU_MASK);
 384         rtc_tm->tm_wday = bcd2bin(reg[3] & AC100_RTC_WEE_MASK);
 385         rtc_tm->tm_mday = bcd2bin(reg[4] & AC100_RTC_DAY_MASK);
 386         rtc_tm->tm_mon  = bcd2bin(reg[5] & AC100_RTC_MON_MASK) - 1;
 387         rtc_tm->tm_year = bcd2bin(reg[6] & AC100_RTC_YEA_MASK) +
 388                           AC100_YEAR_OFF;
 389
 390         return rtc_valid_tm(rtc_tm);
 391 }
 392
 393 static int ac100_rtc_set_time(struct device *dev, struct rtc_time *rtc_tm)
 394 {
 395         struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
 396         struct regmap *regmap = chip->regmap;
 397         int year;
 398         u16 reg[8];
 399
 400         /* our RTC has a limited year range... */
 401         year = rtc_tm->tm_year - AC100_YEAR_OFF;
 402         if (year < 0 || year > (AC100_YEAR_MAX - 1900)) {
 403                 dev_err(dev, "rtc only supports year in range %d - %d\n",
 404                         AC100_YEAR_MIN, AC100_YEAR_MAX);
 405                 return -EINVAL;
 406         }
 407
 408         /* convert to BCD */
 409         reg[0] = bin2bcd(rtc_tm->tm_sec)     & AC100_RTC_SEC_MASK;
 410         reg[1] = bin2bcd(rtc_tm->tm_min)     & AC100_RTC_MIN_MASK;
 411         reg[2] = bin2bcd(rtc_tm->tm_hour)    & AC100_RTC_HOU_MASK;
 412         reg[3] = bin2bcd(rtc_tm->tm_wday)    & AC100_RTC_WEE_MASK;
 413         reg[4] = bin2bcd(rtc_tm->tm_mday)    & AC100_RTC_DAY_MASK;
 414         reg[5] = bin2bcd(rtc_tm->tm_mon + 1) & AC100_RTC_MON_MASK;
 415         reg[6] = bin2bcd(year)               & AC100_RTC_YEA_MASK;
 416         /* trigger write */
 417         reg[7] = AC100_RTC_UPD_TRIGGER;
 418
 419         /* Is it a leap year? */
 420         if (is_leap_year(year + AC100_YEAR_OFF + 1900))
 421                 reg[6] |= AC100_RTC_YEA_LEAP;
 422
 423         return regmap_bulk_write(regmap, AC100_RTC_SEC, reg, 8);
 424 }
 425
 426 static int ac100_rtc_alarm_irq_enable(struct device *dev, unsigned int en)
 427 {
 428         struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
 429         struct regmap *regmap = chip->regmap;
 430         unsigned int val;
 431
 432         val = en ? AC100_ALM_INT_ENABLE : 0;
 433
 434         return regmap_write(regmap, AC100_ALM_INT_ENA, val);
 435 }
 436
 437 static int ac100_rtc_get_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 438 {
 439         struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
 440         struct regmap *regmap = chip->regmap;
 441         struct rtc_time *alrm_tm = &alrm->time;
 442         u16 reg[7];
 443         unsigned int val;
 444         int ret;
 445
 446         ret = regmap_read(regmap, AC100_ALM_INT_ENA, &val);
 447         if (ret)
 448                 return ret;
 449
 450         alrm->enabled = !!(val & AC100_ALM_INT_ENABLE);
 451
 452         ret = regmap_bulk_read(regmap, AC100_ALM_SEC, reg, 7);
 453         if (ret)
 454                 return ret;
 455
 456         alrm_tm->tm_sec  = bcd2bin(reg[0] & AC100_ALM_SEC_MASK);
 457         alrm_tm->tm_min  = bcd2bin(reg[1] & AC100_ALM_MIN_MASK);
 458         alrm_tm->tm_hour = bcd2bin(reg[2] & AC100_ALM_HOU_MASK);
 459         alrm_tm->tm_wday = bcd2bin(reg[3] & AC100_ALM_WEE_MASK);
 460         alrm_tm->tm_mday = bcd2bin(reg[4] & AC100_ALM_DAY_MASK);
 461         alrm_tm->tm_mon  = bcd2bin(reg[5] & AC100_ALM_MON_MASK) - 1;
 462         alrm_tm->tm_year = bcd2bin(reg[6] & AC100_ALM_YEA_MASK) +
 463                            AC100_YEAR_OFF;
 464
 465         return 0;
 466 }
 467
 468 static int ac100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 469 {
 470         struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
 471         struct regmap *regmap = chip->regmap;
 472         struct rtc_time *alrm_tm = &alrm->time;
 473         u16 reg[8];
 474         int year;
 475         int ret;
 476
 477         /* our alarm has a limited year range... */
 478         year = alrm_tm->tm_year - AC100_YEAR_OFF;
 479         if (year < 0 || year > (AC100_YEAR_MAX - 1900)) {
 480                 dev_err(dev, "alarm only supports year in range %d - %d\n",
 481                         AC100_YEAR_MIN, AC100_YEAR_MAX);
 482                 return -EINVAL;
 483         }
 484
 485         /* convert to BCD */
 486         reg[0] = (bin2bcd(alrm_tm->tm_sec)  & AC100_ALM_SEC_MASK) |
 487                         AC100_ALM_ENABLE_FLAG;
 488         reg[1] = (bin2bcd(alrm_tm->tm_min)  & AC100_ALM_MIN_MASK) |
 489                         AC100_ALM_ENABLE_FLAG;
 490         reg[2] = (bin2bcd(alrm_tm->tm_hour) & AC100_ALM_HOU_MASK) |
 491                         AC100_ALM_ENABLE_FLAG;
 492         /* Do not enable weekday alarm */
 493         reg[3] = bin2bcd(alrm_tm->tm_wday) & AC100_ALM_WEE_MASK;
 494         reg[4] = (bin2bcd(alrm_tm->tm_mday) & AC100_ALM_DAY_MASK) |
 495                         AC100_ALM_ENABLE_FLAG;
 496         reg[5] = (bin2bcd(alrm_tm->tm_mon + 1)  & AC100_ALM_MON_MASK) |
 497                         AC100_ALM_ENABLE_FLAG;
 498         reg[6] = (bin2bcd(year) & AC100_ALM_YEA_MASK) |
 499                         AC100_ALM_ENABLE_FLAG;
 500         /* trigger write */
 501         reg[7] = AC100_ALM_UPD_TRIGGER;
 502
 503         ret = regmap_bulk_write(regmap, AC100_ALM_SEC, reg, 8);
 504         if (ret)
 505                 return ret;
 506
 507         return ac100_rtc_alarm_irq_enable(dev, alrm->enabled);
 508 }
 509
 510 static irqreturn_t ac100_rtc_irq(int irq, void *data)
 511 {
 512         struct ac100_rtc_dev *chip = data;
 513         struct regmap *regmap = chip->regmap;
 514         unsigned int val = 0;
 515         int ret;
 516
 517         mutex_lock(&chip->rtc->ops_lock);
 518
 519         /* read status */
 520         ret = regmap_read(regmap, AC100_ALM_INT_STA, &val);
 521         if (ret)
 522                 goto out;
 523
 524         if (val & AC100_ALM_INT_ENABLE) {
 525                 /* signal rtc framework */
 526                 rtc_update_irq(chip->rtc, 1, RTC_AF | RTC_IRQF);
 527
 528                 /* clear status */
 529                 ret = regmap_write(regmap, AC100_ALM_INT_STA, val);
 530                 if (ret)
 531                         goto out;
 532
 533                 /* disable interrupt */
 534                 ret = ac100_rtc_alarm_irq_enable(chip->dev, 0);
 535                 if (ret)
 536                         goto out;
 537         }
 538
 539 out:
 540         mutex_unlock(&chip->rtc->ops_lock);
 541         return IRQ_HANDLED;
 542 }
 543
 544 static const struct rtc_class_ops ac100_rtc_ops = {
 545         .read_time        = ac100_rtc_get_time,
 546         .set_time         = ac100_rtc_set_time,
 547         .read_alarm       = ac100_rtc_get_alarm,
 548         .set_alarm        = ac100_rtc_set_alarm,
 549         .alarm_irq_enable = ac100_rtc_alarm_irq_enable,
 550 };
 551
 552 static int ac100_rtc_probe(struct platform_device *pdev)
 553 {
 554         struct ac100_dev *ac100 = dev_get_drvdata(pdev->dev.parent);
 555         struct ac100_rtc_dev *chip;
 556         int ret;
 557
 558         chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
 559         if (!chip)
 560                 return -ENOMEM;
 561
 562         platform_set_drvdata(pdev, chip);
 563         chip->dev = &pdev->dev;
 564         chip->regmap = ac100->regmap;
 565
 566         chip->irq = platform_get_irq(pdev, 0);
 567         if (chip->irq < 0) {
 568                 dev_err(&pdev->dev, "No IRQ resource\n");
 569                 return chip->irq;
 570         }
 571
 572         chip->rtc = devm_rtc_allocate_device(&pdev->dev);
 573         if (IS_ERR(chip->rtc))
 574                 return PTR_ERR(chip->rtc);
 575
 576         chip->rtc->ops = &ac100_rtc_ops;
 577
 578         ret = devm_request_threaded_irq(&pdev->dev, chip->irq, NULL,
 579                                         ac100_rtc_irq,
 580                                         IRQF_SHARED | IRQF_ONESHOT,
 581                                         dev_name(&pdev->dev), chip);
 582         if (ret) {
 583                 dev_err(&pdev->dev, "Could not request IRQ\n");
 584                 return ret;
 585         }
 586
 587         /* always use 24 hour mode */
 588         regmap_write_bits(chip->regmap, AC100_RTC_CTRL, AC100_RTC_CTRL_24HOUR,
 589                           AC100_RTC_CTRL_24HOUR);
 590
 591         /* disable counter alarm interrupt */
 592         regmap_write(chip->regmap, AC100_ALM_INT_ENA, 0);
 593
 594         /* clear counter alarm pending interrupts */
 595         regmap_write(chip->regmap, AC100_ALM_INT_STA, AC100_ALM_INT_ENABLE);
 596
 597         ret = ac100_rtc_register_clks(chip);
 598         if (ret)
 599                 return ret;
 600
 601         ret = rtc_register_device(chip->rtc);
 602         if (ret) {
 603                 dev_err(&pdev->dev, "unable to register device\n");
 604                 return ret;
 605         }
 606
 607         dev_info(&pdev->dev, "RTC enabled\n");
 608
 609         return 0;
 610 }
 611
 612 static int ac100_rtc_remove(struct platform_device *pdev)
 613 {
 614         struct ac100_rtc_dev *chip = platform_get_drvdata(pdev);
 615
 616         ac100_rtc_unregister_clks(chip);
 617
 618         return 0;
 619 }
 620
 621 static const struct of_device_id ac100_rtc_match[] = {
 622         { .compatible = "x-powers,ac100-rtc" },
 623         { },
 624 };
 625 MODULE_DEVICE_TABLE(of, ac100_rtc_match);
 626
 627 static struct platform_driver ac100_rtc_driver = {
 628         .probe          = ac100_rtc_probe,
 629         .remove         = ac100_rtc_remove,
 630         .driver         = {
 631                 .name           = "ac100-rtc",
 632                 .of_match_table = of_match_ptr(ac100_rtc_match),
 633         },
 634 };
 635 module_platform_driver(ac100_rtc_driver);
 636
 637 MODULE_DESCRIPTION("X-Powers AC100 RTC driver");
 638 MODULE_AUTHOR("Chen-Yu Tsai <wens@csie.org>");
 639 MODULE_LICENSE("GPL v2");