drivers/rtc/rtc-ac100.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * RTC Driver for X-Powers AC100
   4  *
   5  * Copyright (c) 2016 Chen-Yu Tsai
   6  *
   7  * Chen-Yu Tsai <wens@csie.org>
   8  */
   9
  10 #include <linux/bcd.h>
  11 #include <linux/clk-provider.h>
  12 #include <linux/device.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/kernel.h>
  15 #include <linux/mfd/ac100.h>
  16 #include <linux/module.h>
  17 #include <linux/mutex.h>
  18 #include <linux/of.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/regmap.h>
  21 #include <linux/rtc.h>
  22 #include <linux/types.h>
  23
  24 /* Control register */
  25 #define AC100_RTC_CTRL_24HOUR   BIT(0)
  26
  27 /* Clock output register bits */
  28 #define AC100_CLKOUT_PRE_DIV_SHIFT      5
  29 #define AC100_CLKOUT_PRE_DIV_WIDTH      3
  30 #define AC100_CLKOUT_MUX_SHIFT          4
  31 #define AC100_CLKOUT_MUX_WIDTH          1
  32 #define AC100_CLKOUT_DIV_SHIFT          1
  33 #define AC100_CLKOUT_DIV_WIDTH          3
  34 #define AC100_CLKOUT_EN                 BIT(0)
  35
  36 /* RTC */
  37 #define AC100_RTC_SEC_MASK      GENMASK(6, 0)
  38 #define AC100_RTC_MIN_MASK      GENMASK(6, 0)
  39 #define AC100_RTC_HOU_MASK      GENMASK(5, 0)
  40 #define AC100_RTC_WEE_MASK      GENMASK(2, 0)
  41 #define AC100_RTC_DAY_MASK      GENMASK(5, 0)
  42 #define AC100_RTC_MON_MASK      GENMASK(4, 0)
  43 #define AC100_RTC_YEA_MASK      GENMASK(7, 0)
  44 #define AC100_RTC_YEA_LEAP      BIT(15)
  45 #define AC100_RTC_UPD_TRIGGER   BIT(15)
  46
  47 /* Alarm (wall clock) */
  48 #define AC100_ALM_INT_ENABLE    BIT(0)
  49
  50 #define AC100_ALM_SEC_MASK      GENMASK(6, 0)
  51 #define AC100_ALM_MIN_MASK      GENMASK(6, 0)
  52 #define AC100_ALM_HOU_MASK      GENMASK(5, 0)
  53 #define AC100_ALM_WEE_MASK      GENMASK(2, 0)
  54 #define AC100_ALM_DAY_MASK      GENMASK(5, 0)
  55 #define AC100_ALM_MON_MASK      GENMASK(4, 0)
  56 #define AC100_ALM_YEA_MASK      GENMASK(7, 0)
  57 #define AC100_ALM_ENABLE_FLAG   BIT(15)
  58 #define AC100_ALM_UPD_TRIGGER   BIT(15)
  59
  60 /*
  61  * The year parameter passed to the driver is usually an offset relative to
  62  * the year 1900. This macro is used to convert this offset to another one
  63  * relative to the minimum year allowed by the hardware.
  64  *
  65  * The year range is 1970 - 2069. This range is selected to match Allwinner's
  66  * driver.
  67  */
  68 #define AC100_YEAR_MIN                          1970
  69 #define AC100_YEAR_MAX                          2069
  70 #define AC100_YEAR_OFF                          (AC100_YEAR_MIN - 1900)
  71
  72 struct ac100_clkout {
  73         struct clk_hw hw;
  74         struct regmap *regmap;
  75         u8 offset;
  76 };
  77
  78 #define to_ac100_clkout(_hw) container_of(_hw, struct ac100_clkout, hw)
  79
  80 #define AC100_RTC_32K_NAME      "ac100-rtc-32k"
  81 #define AC100_RTC_32K_RATE      32768
  82 #define AC100_CLKOUT_NUM        3
  83
  84 static const char * const ac100_clkout_names[AC100_CLKOUT_NUM] = {
  85         "ac100-cko1-rtc",
  86         "ac100-cko2-rtc",
  87         "ac100-cko3-rtc",
  88 };
  89
  90 struct ac100_rtc_dev {
  91         struct rtc_device *rtc;
  92         struct device *dev;
  93         struct regmap *regmap;
  94         int irq;
  95         unsigned long alarm;
  96
  97         struct clk_hw *rtc_32k_clk;
  98         struct ac100_clkout clks[AC100_CLKOUT_NUM];
  99         struct clk_hw_onecell_data *clk_data;
 100 };
 101
 102 /**
 103  * Clock controls for 3 clock output pins
 104  */
 105
 106 static const struct clk_div_table ac100_clkout_prediv[] = {
 107         { .val = 0, .div = 1 },
 108         { .val = 1, .div = 2 },
 109         { .val = 2, .div = 4 },
 110         { .val = 3, .div = 8 },
 111         { .val = 4, .div = 16 },
 112         { .val = 5, .div = 32 },
 113         { .val = 6, .div = 64 },
 114         { .val = 7, .div = 122 },
 115         { },
 116 };
 117
 118 /* Abuse the fact that one parent is 32768 Hz, and the other is 4 MHz */
 119 static unsigned long ac100_clkout_recalc_rate(struct clk_hw *hw,
 120                                               unsigned long prate)
 121 {
 122         struct ac100_clkout *clk = to_ac100_clkout(hw);
 123         unsigned int reg, div;
 124
 125         regmap_read(clk->regmap, clk->offset, &reg);
 126
 127         /* Handle pre-divider first */
 128         if (prate != AC100_RTC_32K_RATE) {
 129                 div = (reg >> AC100_CLKOUT_PRE_DIV_SHIFT) &
 130                         ((1 << AC100_CLKOUT_PRE_DIV_WIDTH) - 1);
 131                 prate = divider_recalc_rate(hw, prate, div,
 132                                             ac100_clkout_prediv, 0,
 133                                             AC100_CLKOUT_PRE_DIV_WIDTH);
 134         }
 135
 136         div = (reg >> AC100_CLKOUT_DIV_SHIFT) &
 137                 (BIT(AC100_CLKOUT_DIV_WIDTH) - 1);
 138         return divider_recalc_rate(hw, prate, div, NULL,
 139                                    CLK_DIVIDER_POWER_OF_TWO,
 140                                    AC100_CLKOUT_DIV_WIDTH);
 141 }
 142
 143 static long ac100_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
 144                                     unsigned long prate)
 145 {
 146         unsigned long best_rate = 0, tmp_rate, tmp_prate;
 147         int i;
 148
 149         if (prate == AC100_RTC_32K_RATE)
 150                 return divider_round_rate(hw, rate, &prate, NULL,
 151                                           AC100_CLKOUT_DIV_WIDTH,
 152                                           CLK_DIVIDER_POWER_OF_TWO);
 153
 154         for (i = 0; ac100_clkout_prediv[i].div; i++) {
 155                 tmp_prate = DIV_ROUND_UP(prate, ac100_clkout_prediv[i].val);
 156                 tmp_rate = divider_round_rate(hw, rate, &tmp_prate, NULL,
 157                                               AC100_CLKOUT_DIV_WIDTH,
 158                                               CLK_DIVIDER_POWER_OF_TWO);
 159
 160                 if (tmp_rate > rate)
 161                         continue;
 162                 if (rate - tmp_rate < best_rate - tmp_rate)
 163                         best_rate = tmp_rate;
 164         }
 165
 166         return best_rate;
 167 }
 168
 169 static int ac100_clkout_determine_rate(struct clk_hw *hw,
 170                                        struct clk_rate_request *req)
 171 {
 172         struct clk_hw *best_parent;
 173         unsigned long best = 0;
 174         int i, num_parents = clk_hw_get_num_parents(hw);
 175
 176         for (i = 0; i < num_parents; i++) {
 177                 struct clk_hw *parent = clk_hw_get_parent_by_index(hw, i);
 178                 unsigned long tmp, prate;
 179
 180                 /*
 181                  * The clock has two parents, one is a fixed clock which is
 182                  * internally registered by the ac100 driver. The other parent
 183                  * is a clock from the codec side of the chip, which we
 184                  * properly declare and reference in the devicetree and is
 185                  * not implemented in any driver right now.
 186                  * If the clock core looks for the parent of that second
 187                  * missing clock, it can't find one that is registered and
 188                  * returns NULL.
 189                  * So we end up in a situation where clk_hw_get_num_parents
 190                  * returns the amount of clocks we can be parented to, but
 191                  * clk_hw_get_parent_by_index will not return the orphan
 192                  * clocks.
 193                  * Thus we need to check if the parent exists before
 194                  * we get the parent rate, so we could use the RTC
 195                  * without waiting for the codec to be supported.
 196                  */
 197                 if (!parent)
 198                         continue;
 199
 200                 prate = clk_hw_get_rate(parent);
 201
 202                 tmp = ac100_clkout_round_rate(hw, req->rate, prate);
 203
 204                 if (tmp > req->rate)
 205                         continue;
 206                 if (req->rate - tmp < req->rate - best) {
 207                         best = tmp;
 208                         best_parent = parent;
 209                 }
 210         }
 211
 212         if (!best)
 213                 return -EINVAL;
 214
 215         req->best_parent_hw = best_parent;
 216         req->best_parent_rate = best;
 217         req->rate = best;
 218
 219         return 0;
 220 }
 221
 222 static int ac100_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
 223                                  unsigned long prate)
 224 {
 225         struct ac100_clkout *clk = to_ac100_clkout(hw);
 226         int div = 0, pre_div = 0;
 227
 228         do {
 229                 div = divider_get_val(rate * ac100_clkout_prediv[pre_div].div,
 230                                       prate, NULL, AC100_CLKOUT_DIV_WIDTH,
 231                                       CLK_DIVIDER_POWER_OF_TWO);
 232                 if (div >= 0)
 233                         break;
 234         } while (prate != AC100_RTC_32K_RATE &&
 235                  ac100_clkout_prediv[++pre_div].div);
 236
 237         if (div < 0)
 238                 return div;
 239
 240         pre_div = ac100_clkout_prediv[pre_div].val;
 241
 242         regmap_update_bits(clk->regmap, clk->offset,
 243                            ((1 << AC100_CLKOUT_DIV_WIDTH) - 1) << AC100_CLKOUT_DIV_SHIFT |
 244                            ((1 << AC100_CLKOUT_PRE_DIV_WIDTH) - 1) << AC100_CLKOUT_PRE_DIV_SHIFT,
 245                            (div - 1) << AC100_CLKOUT_DIV_SHIFT |
 246                            (pre_div - 1) << AC100_CLKOUT_PRE_DIV_SHIFT);
 247
 248         return 0;
 249 }
 250
 251 static int ac100_clkout_prepare(struct clk_hw *hw)
 252 {
 253         struct ac100_clkout *clk = to_ac100_clkout(hw);
 254
 255         return regmap_update_bits(clk->regmap, clk->offset, AC100_CLKOUT_EN,
 256                                   AC100_CLKOUT_EN);
 257 }
 258
 259 static void ac100_clkout_unprepare(struct clk_hw *hw)
 260 {
 261         struct ac100_clkout *clk = to_ac100_clkout(hw);
 262
 263         regmap_update_bits(clk->regmap, clk->offset, AC100_CLKOUT_EN, 0);
 264 }
 265
 266 static int ac100_clkout_is_prepared(struct clk_hw *hw)
 267 {
 268         struct ac100_clkout *clk = to_ac100_clkout(hw);
 269         unsigned int reg;
 270
 271         regmap_read(clk->regmap, clk->offset, &reg);
 272
 273         return reg & AC100_CLKOUT_EN;
 274 }
 275
 276 static u8 ac100_clkout_get_parent(struct clk_hw *hw)
 277 {
 278         struct ac100_clkout *clk = to_ac100_clkout(hw);
 279         unsigned int reg;
 280
 281         regmap_read(clk->regmap, clk->offset, &reg);
 282
 283         return (reg >> AC100_CLKOUT_MUX_SHIFT) & 0x1;
 284 }
 285
 286 static int ac100_clkout_set_parent(struct clk_hw *hw, u8 index)
 287 {
 288         struct ac100_clkout *clk = to_ac100_clkout(hw);
 289
 290         return regmap_update_bits(clk->regmap, clk->offset,
 291                                   BIT(AC100_CLKOUT_MUX_SHIFT),
 292                                   index ? BIT(AC100_CLKOUT_MUX_SHIFT) : 0);
 293 }
 294
 295 static const struct clk_ops ac100_clkout_ops = {
 296         .prepare        = ac100_clkout_prepare,
 297         .unprepare      = ac100_clkout_unprepare,
 298         .is_prepared    = ac100_clkout_is_prepared,
 299         .recalc_rate    = ac100_clkout_recalc_rate,
 300         .determine_rate = ac100_clkout_determine_rate,
 301         .get_parent     = ac100_clkout_get_parent,
 302         .set_parent     = ac100_clkout_set_parent,
 303         .set_rate       = ac100_clkout_set_rate,
 304 };
 305
 306 static int ac100_rtc_register_clks(struct ac100_rtc_dev *chip)
 307 {
 308         struct device_node *np = chip->dev->of_node;
 309         const char *parents[2] = {AC100_RTC_32K_NAME};
 310         int i, ret;
 311
 312         chip->clk_data = devm_kzalloc(chip->dev,
 313                                       struct_size(chip->clk_data, hws,
 314                                                   AC100_CLKOUT_NUM),
 315                                       GFP_KERNEL);
 316         if (!chip->clk_data)
 317                 return -ENOMEM;
 318
 319         chip->rtc_32k_clk = clk_hw_register_fixed_rate(chip->dev,
 320                                                        AC100_RTC_32K_NAME,
 321                                                        NULL, 0,
 322                                                        AC100_RTC_32K_RATE);
 323         if (IS_ERR(chip->rtc_32k_clk)) {
 324                 ret = PTR_ERR(chip->rtc_32k_clk);
 325                 dev_err(chip->dev, "Failed to register RTC-32k clock: %d\n",
 326                         ret);
 327                 return ret;
 328         }
 329
 330         parents[1] = of_clk_get_parent_name(np, 0);
 331         if (!parents[1]) {
 332                 dev_err(chip->dev, "Failed to get ADDA 4M clock\n");
 333                 return -EINVAL;
 334         }
 335
 336         for (i = 0; i < AC100_CLKOUT_NUM; i++) {
 337                 struct ac100_clkout *clk = &chip->clks[i];
 338                 struct clk_init_data init = {
 339                         .name = ac100_clkout_names[i],
 340                         .ops = &ac100_clkout_ops,
 341                         .parent_names = parents,
 342                         .num_parents = ARRAY_SIZE(parents),
 343                         .flags = 0,
 344                 };
 345
 346                 of_property_read_string_index(np, "clock-output-names",
 347                                               i, &init.name);
 348                 clk->regmap = chip->regmap;
 349                 clk->offset = AC100_CLKOUT_CTRL1 + i;
 350                 clk->hw.init = &init;
 351
 352                 ret = devm_clk_hw_register(chip->dev, &clk->hw);
 353                 if (ret) {
 354                         dev_err(chip->dev, "Failed to register clk '%s': %d\n",
 355                                 init.name, ret);
 356                         goto err_unregister_rtc_32k;
 357                 }
 358
 359                 chip->clk_data->hws[i] = &clk->hw;
 360         }
 361
 362         chip->clk_data->num = i;
 363         ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, chip->clk_data);
 364         if (ret)
 365                 goto err_unregister_rtc_32k;
 366
 367         return 0;
 368
 369 err_unregister_rtc_32k:
 370         clk_unregister_fixed_rate(chip->rtc_32k_clk->clk);
 371
 372         return ret;
 373 }
 374
 375 static void ac100_rtc_unregister_clks(struct ac100_rtc_dev *chip)
 376 {
 377         of_clk_del_provider(chip->dev->of_node);
 378         clk_unregister_fixed_rate(chip->rtc_32k_clk->clk);
 379 }
 380
 381 /**
 382  * RTC related bits
 383  */
 384 static int ac100_rtc_get_time(struct device *dev, struct rtc_time *rtc_tm)
 385 {
 386         struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
 387         struct regmap *regmap = chip->regmap;
 388         u16 reg[7];
 389         int ret;
 390
 391         ret = regmap_bulk_read(regmap, AC100_RTC_SEC, reg, 7);
 392         if (ret)
 393                 return ret;
 394
 395         rtc_tm->tm_sec  = bcd2bin(reg[0] & AC100_RTC_SEC_MASK);
 396         rtc_tm->tm_min  = bcd2bin(reg[1] & AC100_RTC_MIN_MASK);
 397         rtc_tm->tm_hour = bcd2bin(reg[2] & AC100_RTC_HOU_MASK);
 398         rtc_tm->tm_wday = bcd2bin(reg[3] & AC100_RTC_WEE_MASK);
 399         rtc_tm->tm_mday = bcd2bin(reg[4] & AC100_RTC_DAY_MASK);
 400         rtc_tm->tm_mon  = bcd2bin(reg[5] & AC100_RTC_MON_MASK) - 1;
 401         rtc_tm->tm_year = bcd2bin(reg[6] & AC100_RTC_YEA_MASK) +
 402                           AC100_YEAR_OFF;
 403
 404         return 0;
 405 }
 406
 407 static int ac100_rtc_set_time(struct device *dev, struct rtc_time *rtc_tm)
 408 {
 409         struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
 410         struct regmap *regmap = chip->regmap;
 411         int year;
 412         u16 reg[8];
 413
 414         /* our RTC has a limited year range... */
 415         year = rtc_tm->tm_year - AC100_YEAR_OFF;
 416         if (year < 0 || year > (AC100_YEAR_MAX - 1900)) {
 417                 dev_err(dev, "rtc only supports year in range %d - %d\n",
 418                         AC100_YEAR_MIN, AC100_YEAR_MAX);
 419                 return -EINVAL;
 420         }
 421
 422         /* convert to BCD */
 423         reg[0] = bin2bcd(rtc_tm->tm_sec)     & AC100_RTC_SEC_MASK;
 424         reg[1] = bin2bcd(rtc_tm->tm_min)     & AC100_RTC_MIN_MASK;
 425         reg[2] = bin2bcd(rtc_tm->tm_hour)    & AC100_RTC_HOU_MASK;
 426         reg[3] = bin2bcd(rtc_tm->tm_wday)    & AC100_RTC_WEE_MASK;
 427         reg[4] = bin2bcd(rtc_tm->tm_mday)    & AC100_RTC_DAY_MASK;
 428         reg[5] = bin2bcd(rtc_tm->tm_mon + 1) & AC100_RTC_MON_MASK;
 429         reg[6] = bin2bcd(year)               & AC100_RTC_YEA_MASK;
 430         /* trigger write */
 431         reg[7] = AC100_RTC_UPD_TRIGGER;
 432
 433         /* Is it a leap year? */
 434         if (is_leap_year(year + AC100_YEAR_OFF + 1900))
 435                 reg[6] |= AC100_RTC_YEA_LEAP;
 436
 437         return regmap_bulk_write(regmap, AC100_RTC_SEC, reg, 8);
 438 }
 439
 440 static int ac100_rtc_alarm_irq_enable(struct device *dev, unsigned int en)
 441 {
 442         struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
 443         struct regmap *regmap = chip->regmap;
 444         unsigned int val;
 445
 446         val = en ? AC100_ALM_INT_ENABLE : 0;
 447
 448         return regmap_write(regmap, AC100_ALM_INT_ENA, val);
 449 }
 450
 451 static int ac100_rtc_get_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 452 {
 453         struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
 454         struct regmap *regmap = chip->regmap;
 455         struct rtc_time *alrm_tm = &alrm->time;
 456         u16 reg[7];
 457         unsigned int val;
 458         int ret;
 459
 460         ret = regmap_read(regmap, AC100_ALM_INT_ENA, &val);
 461         if (ret)
 462                 return ret;
 463
 464         alrm->enabled = !!(val & AC100_ALM_INT_ENABLE);
 465
 466         ret = regmap_bulk_read(regmap, AC100_ALM_SEC, reg, 7);
 467         if (ret)
 468                 return ret;
 469
 470         alrm_tm->tm_sec  = bcd2bin(reg[0] & AC100_ALM_SEC_MASK);
 471         alrm_tm->tm_min  = bcd2bin(reg[1] & AC100_ALM_MIN_MASK);
 472         alrm_tm->tm_hour = bcd2bin(reg[2] & AC100_ALM_HOU_MASK);
 473         alrm_tm->tm_wday = bcd2bin(reg[3] & AC100_ALM_WEE_MASK);
 474         alrm_tm->tm_mday = bcd2bin(reg[4] & AC100_ALM_DAY_MASK);
 475         alrm_tm->tm_mon  = bcd2bin(reg[5] & AC100_ALM_MON_MASK) - 1;
 476         alrm_tm->tm_year = bcd2bin(reg[6] & AC100_ALM_YEA_MASK) +
 477                            AC100_YEAR_OFF;
 478
 479         return 0;
 480 }
 481
 482 static int ac100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 483 {
 484         struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
 485         struct regmap *regmap = chip->regmap;
 486         struct rtc_time *alrm_tm = &alrm->time;
 487         u16 reg[8];
 488         int year;
 489         int ret;
 490
 491         /* our alarm has a limited year range... */
 492         year = alrm_tm->tm_year - AC100_YEAR_OFF;
 493         if (year < 0 || year > (AC100_YEAR_MAX - 1900)) {
 494                 dev_err(dev, "alarm only supports year in range %d - %d\n",
 495                         AC100_YEAR_MIN, AC100_YEAR_MAX);
 496                 return -EINVAL;
 497         }
 498
 499         /* convert to BCD */
 500         reg[0] = (bin2bcd(alrm_tm->tm_sec)  & AC100_ALM_SEC_MASK) |
 501                         AC100_ALM_ENABLE_FLAG;
 502         reg[1] = (bin2bcd(alrm_tm->tm_min)  & AC100_ALM_MIN_MASK) |
 503                         AC100_ALM_ENABLE_FLAG;
 504         reg[2] = (bin2bcd(alrm_tm->tm_hour) & AC100_ALM_HOU_MASK) |
 505                         AC100_ALM_ENABLE_FLAG;
 506         /* Do not enable weekday alarm */
 507         reg[3] = bin2bcd(alrm_tm->tm_wday) & AC100_ALM_WEE_MASK;
 508         reg[4] = (bin2bcd(alrm_tm->tm_mday) & AC100_ALM_DAY_MASK) |
 509                         AC100_ALM_ENABLE_FLAG;
 510         reg[5] = (bin2bcd(alrm_tm->tm_mon + 1)  & AC100_ALM_MON_MASK) |
 511                         AC100_ALM_ENABLE_FLAG;
 512         reg[6] = (bin2bcd(year) & AC100_ALM_YEA_MASK) |
 513                         AC100_ALM_ENABLE_FLAG;
 514         /* trigger write */
 515         reg[7] = AC100_ALM_UPD_TRIGGER;
 516
 517         ret = regmap_bulk_write(regmap, AC100_ALM_SEC, reg, 8);
 518         if (ret)
 519                 return ret;
 520
 521         return ac100_rtc_alarm_irq_enable(dev, alrm->enabled);
 522 }
 523
 524 static irqreturn_t ac100_rtc_irq(int irq, void *data)
 525 {
 526         struct ac100_rtc_dev *chip = data;
 527         struct regmap *regmap = chip->regmap;
 528         unsigned int val = 0;
 529         int ret;
 530
 531         mutex_lock(&chip->rtc->ops_lock);
 532
 533         /* read status */
 534         ret = regmap_read(regmap, AC100_ALM_INT_STA, &val);
 535         if (ret)
 536                 goto out;
 537
 538         if (val & AC100_ALM_INT_ENABLE) {
 539                 /* signal rtc framework */
 540                 rtc_update_irq(chip->rtc, 1, RTC_AF | RTC_IRQF);
 541
 542                 /* clear status */
 543                 ret = regmap_write(regmap, AC100_ALM_INT_STA, val);
 544                 if (ret)
 545                         goto out;
 546
 547                 /* disable interrupt */
 548                 ret = ac100_rtc_alarm_irq_enable(chip->dev, 0);
 549                 if (ret)
 550                         goto out;
 551         }
 552
 553 out:
 554         mutex_unlock(&chip->rtc->ops_lock);
 555         return IRQ_HANDLED;
 556 }
 557
 558 static const struct rtc_class_ops ac100_rtc_ops = {
 559         .read_time        = ac100_rtc_get_time,
 560         .set_time         = ac100_rtc_set_time,
 561         .read_alarm       = ac100_rtc_get_alarm,
 562         .set_alarm        = ac100_rtc_set_alarm,
 563         .alarm_irq_enable = ac100_rtc_alarm_irq_enable,
 564 };
 565
 566 static int ac100_rtc_probe(struct platform_device *pdev)
 567 {
 568         struct ac100_dev *ac100 = dev_get_drvdata(pdev->dev.parent);
 569         struct ac100_rtc_dev *chip;
 570         int ret;
 571
 572         chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
 573         if (!chip)
 574                 return -ENOMEM;
 575
 576         platform_set_drvdata(pdev, chip);
 577         chip->dev = &pdev->dev;
 578         chip->regmap = ac100->regmap;
 579
 580         chip->irq = platform_get_irq(pdev, 0);
 581         if (chip->irq < 0)
 582                 return chip->irq;
 583
 584         chip->rtc = devm_rtc_allocate_device(&pdev->dev);
 585         if (IS_ERR(chip->rtc))
 586                 return PTR_ERR(chip->rtc);
 587
 588         chip->rtc->ops = &ac100_rtc_ops;
 589
 590         ret = devm_request_threaded_irq(&pdev->dev, chip->irq, NULL,
 591                                         ac100_rtc_irq,
 592                                         IRQF_SHARED | IRQF_ONESHOT,
 593                                         dev_name(&pdev->dev), chip);
 594         if (ret) {
 595                 dev_err(&pdev->dev, "Could not request IRQ\n");
 596                 return ret;
 597         }
 598
 599         /* always use 24 hour mode */
 600         regmap_write_bits(chip->regmap, AC100_RTC_CTRL, AC100_RTC_CTRL_24HOUR,
 601                           AC100_RTC_CTRL_24HOUR);
 602
 603         /* disable counter alarm interrupt */
 604         regmap_write(chip->regmap, AC100_ALM_INT_ENA, 0);
 605
 606         /* clear counter alarm pending interrupts */
 607         regmap_write(chip->regmap, AC100_ALM_INT_STA, AC100_ALM_INT_ENABLE);
 608
 609         ret = ac100_rtc_register_clks(chip);
 610         if (ret)
 611                 return ret;
 612
 613         return devm_rtc_register_device(chip->rtc);
 614 }
 615
 616 static int ac100_rtc_remove(struct platform_device *pdev)
 617 {
 618         struct ac100_rtc_dev *chip = platform_get_drvdata(pdev);
 619
 620         ac100_rtc_unregister_clks(chip);
 621
 622         return 0;
 623 }
 624
 625 static const struct of_device_id ac100_rtc_match[] = {
 626         { .compatible = "x-powers,ac100-rtc" },
 627         { },
 628 };
 629 MODULE_DEVICE_TABLE(of, ac100_rtc_match);
 630
 631 static struct platform_driver ac100_rtc_driver = {
 632         .probe          = ac100_rtc_probe,
 633         .remove         = ac100_rtc_remove,
 634         .driver         = {
 635                 .name           = "ac100-rtc",
 636                 .of_match_table = of_match_ptr(ac100_rtc_match),
 637         },
 638 };
 639 module_platform_driver(ac100_rtc_driver);
 640
 641 MODULE_DESCRIPTION("X-Powers AC100 RTC driver");
 642 MODULE_AUTHOR("Chen-Yu Tsai <wens@csie.org>");
 643 MODULE_LICENSE("GPL v2");