drivers/rtc/rtc-sun6i.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * An RTC driver for Allwinner A31/A23
   4  *
   5  * Copyright (c) 2014, Chen-Yu Tsai <[email protected]>
   6  *
   7  * based on rtc-sunxi.c
   8  *
   9  * An RTC driver for Allwinner A10/A20
  10  *
  11  * Copyright (c) 2013, Carlo Caione <[email protected]>
  12  */
  13
  14 #include <linux/clk.h>
  15 #include <linux/clk-provider.h>
  16 #include <linux/delay.h>
  17 #include <linux/err.h>
  18 #include <linux/fs.h>
  19 #include <linux/init.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/io.h>
  22 #include <linux/kernel.h>
  23 #include <linux/module.h>
  24 #include <linux/of.h>
  25 #include <linux/of_address.h>
  26 #include <linux/of_device.h>
  27 #include <linux/platform_device.h>
  28 #include <linux/rtc.h>
  29 #include <linux/slab.h>
  30 #include <linux/types.h>
  31
  32 /* Control register */
  33 #define SUN6I_LOSC_CTRL                         0x0000
  34 #define SUN6I_LOSC_CTRL_KEY                     (0x16aa << 16)
  35 #define SUN6I_LOSC_CTRL_AUTO_SWT_BYPASS         BIT(15)
  36 #define SUN6I_LOSC_CTRL_ALM_DHMS_ACC            BIT(9)
  37 #define SUN6I_LOSC_CTRL_RTC_HMS_ACC             BIT(8)
  38 #define SUN6I_LOSC_CTRL_RTC_YMD_ACC             BIT(7)
  39 #define SUN6I_LOSC_CTRL_EXT_LOSC_EN             BIT(4)
  40 #define SUN6I_LOSC_CTRL_EXT_OSC                 BIT(0)
  41 #define SUN6I_LOSC_CTRL_ACC_MASK                GENMASK(9, 7)
  42
  43 #define SUN6I_LOSC_CLK_PRESCAL                  0x0008
  44
  45 /* RTC */
  46 #define SUN6I_RTC_YMD                           0x0010
  47 #define SUN6I_RTC_HMS                           0x0014
  48
  49 /* Alarm 0 (counter) */
  50 #define SUN6I_ALRM_COUNTER                      0x0020
  51 #define SUN6I_ALRM_CUR_VAL                      0x0024
  52 #define SUN6I_ALRM_EN                           0x0028
  53 #define SUN6I_ALRM_EN_CNT_EN                    BIT(0)
  54 #define SUN6I_ALRM_IRQ_EN                       0x002c
  55 #define SUN6I_ALRM_IRQ_EN_CNT_IRQ_EN            BIT(0)
  56 #define SUN6I_ALRM_IRQ_STA                      0x0030
  57 #define SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND         BIT(0)
  58
  59 /* Alarm 1 (wall clock) */
  60 #define SUN6I_ALRM1_EN                          0x0044
  61 #define SUN6I_ALRM1_IRQ_EN                      0x0048
  62 #define SUN6I_ALRM1_IRQ_STA                     0x004c
  63 #define SUN6I_ALRM1_IRQ_STA_WEEK_IRQ_PEND       BIT(0)
  64
  65 /* Alarm config */
  66 #define SUN6I_ALARM_CONFIG                      0x0050
  67 #define SUN6I_ALARM_CONFIG_WAKEUP               BIT(0)
  68
  69 #define SUN6I_LOSC_OUT_GATING                   0x0060
  70 #define SUN6I_LOSC_OUT_GATING_EN_OFFSET         0
  71
  72 /*
  73  * Get date values
  74  */
  75 #define SUN6I_DATE_GET_DAY_VALUE(x)             ((x)  & 0x0000001f)
  76 #define SUN6I_DATE_GET_MON_VALUE(x)             (((x) & 0x00000f00) >> 8)
  77 #define SUN6I_DATE_GET_YEAR_VALUE(x)            (((x) & 0x003f0000) >> 16)
  78 #define SUN6I_LEAP_GET_VALUE(x)                 (((x) & 0x00400000) >> 22)
  79
  80 /*
  81  * Get time values
  82  */
  83 #define SUN6I_TIME_GET_SEC_VALUE(x)             ((x)  & 0x0000003f)
  84 #define SUN6I_TIME_GET_MIN_VALUE(x)             (((x) & 0x00003f00) >> 8)
  85 #define SUN6I_TIME_GET_HOUR_VALUE(x)            (((x) & 0x001f0000) >> 16)
  86
  87 /*
  88  * Set date values
  89  */
  90 #define SUN6I_DATE_SET_DAY_VALUE(x)             ((x)       & 0x0000001f)
  91 #define SUN6I_DATE_SET_MON_VALUE(x)             ((x) <<  8 & 0x00000f00)
  92 #define SUN6I_DATE_SET_YEAR_VALUE(x)            ((x) << 16 & 0x003f0000)
  93 #define SUN6I_LEAP_SET_VALUE(x)                 ((x) << 22 & 0x00400000)
  94
  95 /*
  96  * Set time values
  97  */
  98 #define SUN6I_TIME_SET_SEC_VALUE(x)             ((x)       & 0x0000003f)
  99 #define SUN6I_TIME_SET_MIN_VALUE(x)             ((x) <<  8 & 0x00003f00)
 100 #define SUN6I_TIME_SET_HOUR_VALUE(x)            ((x) << 16 & 0x001f0000)
 101
 102 /*
 103  * The year parameter passed to the driver is usually an offset relative to
 104  * the year 1900. This macro is used to convert this offset to another one
 105  * relative to the minimum year allowed by the hardware.
 106  *
 107  * The year range is 1970 - 2033. This range is selected to match Allwinner's
 108  * driver, even though it is somewhat limited.
 109  */
 110 #define SUN6I_YEAR_MIN                          1970
 111 #define SUN6I_YEAR_MAX                          2033
 112 #define SUN6I_YEAR_OFF                          (SUN6I_YEAR_MIN - 1900)
 113
 114 /*
 115  * There are other differences between models, including:
 116  *
 117  *   - number of GPIO pins that can be configured to hold a certain level
 118  *   - crypto-key related registers (H5, H6)
 119  *   - boot process related (super standby, secondary processor entry address)
 120  *     registers (R40, H6)
 121  *   - SYS power domain controls (R40)
 122  *   - DCXO controls (H6)
 123  *   - RC oscillator calibration (H6)
 124  *
 125  * These functions are not covered by this driver.
 126  */
 127 struct sun6i_rtc_clk_data {
 128         unsigned long rc_osc_rate;
 129         unsigned int fixed_prescaler : 16;
 130         unsigned int has_prescaler : 1;
 131         unsigned int has_out_clk : 1;
 132         unsigned int export_iosc : 1;
 133         unsigned int has_losc_en : 1;
 134         unsigned int has_auto_swt : 1;
 135 };
 136
 137 struct sun6i_rtc_dev {
 138         struct rtc_device *rtc;
 139         struct device *dev;
 140         const struct sun6i_rtc_clk_data *data;
 141         void __iomem *base;
 142         int irq;
 143         unsigned long alarm;
 144
 145         struct clk_hw hw;
 146         struct clk_hw *int_osc;
 147         struct clk *losc;
 148         struct clk *ext_losc;
 149
 150         spinlock_t lock;
 151 };
 152
 153 static struct sun6i_rtc_dev *sun6i_rtc;
 154
 155 static unsigned long sun6i_rtc_osc_recalc_rate(struct clk_hw *hw,
 156                                                unsigned long parent_rate)
 157 {
 158         struct sun6i_rtc_dev *rtc = container_of(hw, struct sun6i_rtc_dev, hw);
 159         u32 val = 0;
 160
 161         val = readl(rtc->base + SUN6I_LOSC_CTRL);
 162         if (val & SUN6I_LOSC_CTRL_EXT_OSC)
 163                 return parent_rate;
 164
 165         if (rtc->data->fixed_prescaler)
 166                 parent_rate /= rtc->data->fixed_prescaler;
 167
 168         if (rtc->data->has_prescaler) {
 169                 val = readl(rtc->base + SUN6I_LOSC_CLK_PRESCAL);
 170                 val &= GENMASK(4, 0);
 171         }
 172
 173         return parent_rate / (val + 1);
 174 }
 175
 176 static u8 sun6i_rtc_osc_get_parent(struct clk_hw *hw)
 177 {
 178         struct sun6i_rtc_dev *rtc = container_of(hw, struct sun6i_rtc_dev, hw);
 179
 180         return readl(rtc->base + SUN6I_LOSC_CTRL) & SUN6I_LOSC_CTRL_EXT_OSC;
 181 }
 182
 183 static int sun6i_rtc_osc_set_parent(struct clk_hw *hw, u8 index)
 184 {
 185         struct sun6i_rtc_dev *rtc = container_of(hw, struct sun6i_rtc_dev, hw);
 186         unsigned long flags;
 187         u32 val;
 188
 189         if (index > 1)
 190                 return -EINVAL;
 191
 192         spin_lock_irqsave(&rtc->lock, flags);
 193         val = readl(rtc->base + SUN6I_LOSC_CTRL);
 194         val &= ~SUN6I_LOSC_CTRL_EXT_OSC;
 195         val |= SUN6I_LOSC_CTRL_KEY;
 196         val |= index ? SUN6I_LOSC_CTRL_EXT_OSC : 0;
 197         if (rtc->data->has_losc_en) {
 198                 val &= ~SUN6I_LOSC_CTRL_EXT_LOSC_EN;
 199                 val |= index ? SUN6I_LOSC_CTRL_EXT_LOSC_EN : 0;
 200         }
 201         writel(val, rtc->base + SUN6I_LOSC_CTRL);
 202         spin_unlock_irqrestore(&rtc->lock, flags);
 203
 204         return 0;
 205 }
 206
 207 static const struct clk_ops sun6i_rtc_osc_ops = {
 208         .recalc_rate    = sun6i_rtc_osc_recalc_rate,
 209
 210         .get_parent     = sun6i_rtc_osc_get_parent,
 211         .set_parent     = sun6i_rtc_osc_set_parent,
 212 };
 213
 214 static void __init sun6i_rtc_clk_init(struct device_node *node,
 215                                       const struct sun6i_rtc_clk_data *data)
 216 {
 217         struct clk_hw_onecell_data *clk_data;
 218         struct sun6i_rtc_dev *rtc;
 219         struct clk_init_data init = {
 220                 .ops            = &sun6i_rtc_osc_ops,
 221                 .name           = "losc",
 222         };
 223         const char *iosc_name = "rtc-int-osc";
 224         const char *clkout_name = "osc32k-out";
 225         const char *parents[2];
 226         u32 reg;
 227
 228         rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);
 229         if (!rtc)
 230                 return;
 231
 232         rtc->data = data;
 233         clk_data = kzalloc(struct_size(clk_data, hws, 3), GFP_KERNEL);
 234         if (!clk_data) {
 235                 kfree(rtc);
 236                 return;
 237         }
 238
 239         spin_lock_init(&rtc->lock);
 240
 241         rtc->base = of_io_request_and_map(node, 0, of_node_full_name(node));
 242         if (IS_ERR(rtc->base)) {
 243                 pr_crit("Can't map RTC registers");
 244                 goto err;
 245         }
 246
 247         reg = SUN6I_LOSC_CTRL_KEY;
 248         if (rtc->data->has_auto_swt) {
 249                 /* Bypass auto-switch to int osc, on ext losc failure */
 250                 reg |= SUN6I_LOSC_CTRL_AUTO_SWT_BYPASS;
 251                 writel(reg, rtc->base + SUN6I_LOSC_CTRL);
 252         }
 253
 254         /* Switch to the external, more precise, oscillator */
 255         reg |= SUN6I_LOSC_CTRL_EXT_OSC;
 256         if (rtc->data->has_losc_en)
 257                 reg |= SUN6I_LOSC_CTRL_EXT_LOSC_EN;
 258         writel(reg, rtc->base + SUN6I_LOSC_CTRL);
 259
 260         /* Yes, I know, this is ugly. */
 261         sun6i_rtc = rtc;
 262
 263         /* Deal with old DTs */
 264         if (!of_get_property(node, "clocks", NULL))
 265                 goto err;
 266
 267         /* Only read IOSC name from device tree if it is exported */
 268         if (rtc->data->export_iosc)
 269                 of_property_read_string_index(node, "clock-output-names", 2,
 270                                               &iosc_name);
 271
 272         rtc->int_osc = clk_hw_register_fixed_rate_with_accuracy(NULL,
 273                                                                 iosc_name,
 274                                                                 NULL, 0,
 275                                                                 rtc->data->rc_osc_rate,
 276                                                                 300000000);
 277         if (IS_ERR(rtc->int_osc)) {
 278                 pr_crit("Couldn't register the internal oscillator\n");
 279                 return;
 280         }
 281
 282         parents[0] = clk_hw_get_name(rtc->int_osc);
 283         parents[1] = of_clk_get_parent_name(node, 0);
 284
 285         rtc->hw.init = &init;
 286
 287         init.parent_names = parents;
 288         init.num_parents = of_clk_get_parent_count(node) + 1;
 289         of_property_read_string_index(node, "clock-output-names", 0,
 290                                       &init.name);
 291
 292         rtc->losc = clk_register(NULL, &rtc->hw);
 293         if (IS_ERR(rtc->losc)) {
 294                 pr_crit("Couldn't register the LOSC clock\n");
 295                 return;
 296         }
 297
 298         of_property_read_string_index(node, "clock-output-names", 1,
 299                                       &clkout_name);
 300         rtc->ext_losc = clk_register_gate(NULL, clkout_name, init.name,
 301                                           0, rtc->base + SUN6I_LOSC_OUT_GATING,
 302                                           SUN6I_LOSC_OUT_GATING_EN_OFFSET, 0,
 303                                           &rtc->lock);
 304         if (IS_ERR(rtc->ext_losc)) {
 305                 pr_crit("Couldn't register the LOSC external gate\n");
 306                 return;
 307         }
 308
 309         clk_data->num = 2;
 310         clk_data->hws[0] = &rtc->hw;
 311         clk_data->hws[1] = __clk_get_hw(rtc->ext_losc);
 312         if (rtc->data->export_iosc) {
 313                 clk_data->hws[2] = rtc->int_osc;
 314                 clk_data->num = 3;
 315         }
 316         of_clk_add_hw_provider(node, of_clk_hw_onecell_get, clk_data);
 317         return;
 318
 319 err:
 320         kfree(clk_data);
 321 }
 322
 323 static const struct sun6i_rtc_clk_data sun6i_a31_rtc_data = {
 324         .rc_osc_rate = 667000, /* datasheet says 600 ~ 700 KHz */
 325         .has_prescaler = 1,
 326 };
 327
 328 static void __init sun6i_a31_rtc_clk_init(struct device_node *node)
 329 {
 330         sun6i_rtc_clk_init(node, &sun6i_a31_rtc_data);
 331 }
 332 CLK_OF_DECLARE_DRIVER(sun6i_a31_rtc_clk, "allwinner,sun6i-a31-rtc",
 333                       sun6i_a31_rtc_clk_init);
 334
 335 static const struct sun6i_rtc_clk_data sun8i_a23_rtc_data = {
 336         .rc_osc_rate = 667000, /* datasheet says 600 ~ 700 KHz */
 337         .has_prescaler = 1,
 338         .has_out_clk = 1,
 339 };
 340
 341 static void __init sun8i_a23_rtc_clk_init(struct device_node *node)
 342 {
 343         sun6i_rtc_clk_init(node, &sun8i_a23_rtc_data);
 344 }
 345 CLK_OF_DECLARE_DRIVER(sun8i_a23_rtc_clk, "allwinner,sun8i-a23-rtc",
 346                       sun8i_a23_rtc_clk_init);
 347
 348 static const struct sun6i_rtc_clk_data sun8i_h3_rtc_data = {
 349         .rc_osc_rate = 16000000,
 350         .fixed_prescaler = 32,
 351         .has_prescaler = 1,
 352         .has_out_clk = 1,
 353         .export_iosc = 1,
 354 };
 355
 356 static void __init sun8i_h3_rtc_clk_init(struct device_node *node)
 357 {
 358         sun6i_rtc_clk_init(node, &sun8i_h3_rtc_data);
 359 }
 360 CLK_OF_DECLARE_DRIVER(sun8i_h3_rtc_clk, "allwinner,sun8i-h3-rtc",
 361                       sun8i_h3_rtc_clk_init);
 362 /* As far as we are concerned, clocks for H5 are the same as H3 */
 363 CLK_OF_DECLARE_DRIVER(sun50i_h5_rtc_clk, "allwinner,sun50i-h5-rtc",
 364                       sun8i_h3_rtc_clk_init);
 365
 366 static const struct sun6i_rtc_clk_data sun50i_h6_rtc_data = {
 367         .rc_osc_rate = 16000000,
 368         .fixed_prescaler = 32,
 369         .has_prescaler = 1,
 370         .has_out_clk = 1,
 371         .export_iosc = 1,
 372         .has_losc_en = 1,
 373         .has_auto_swt = 1,
 374 };
 375
 376 static void __init sun50i_h6_rtc_clk_init(struct device_node *node)
 377 {
 378         sun6i_rtc_clk_init(node, &sun50i_h6_rtc_data);
 379 }
 380 CLK_OF_DECLARE_DRIVER(sun50i_h6_rtc_clk, "allwinner,sun50i-h6-rtc",
 381                       sun50i_h6_rtc_clk_init);
 382
 383 static const struct sun6i_rtc_clk_data sun8i_v3_rtc_data = {
 384         .rc_osc_rate = 32000,
 385         .has_out_clk = 1,
 386 };
 387
 388 static void __init sun8i_v3_rtc_clk_init(struct device_node *node)
 389 {
 390         sun6i_rtc_clk_init(node, &sun8i_v3_rtc_data);
 391 }
 392 CLK_OF_DECLARE_DRIVER(sun8i_v3_rtc_clk, "allwinner,sun8i-v3-rtc",
 393                       sun8i_v3_rtc_clk_init);
 394
 395 static irqreturn_t sun6i_rtc_alarmirq(int irq, void *id)
 396 {
 397         struct sun6i_rtc_dev *chip = (struct sun6i_rtc_dev *) id;
 398         irqreturn_t ret = IRQ_NONE;
 399         u32 val;
 400
 401         spin_lock(&chip->lock);
 402         val = readl(chip->base + SUN6I_ALRM_IRQ_STA);
 403
 404         if (val & SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND) {
 405                 val |= SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND;
 406                 writel(val, chip->base + SUN6I_ALRM_IRQ_STA);
 407
 408                 rtc_update_irq(chip->rtc, 1, RTC_AF | RTC_IRQF);
 409
 410                 ret = IRQ_HANDLED;
 411         }
 412         spin_unlock(&chip->lock);
 413
 414         return ret;
 415 }
 416
 417 static void sun6i_rtc_setaie(int to, struct sun6i_rtc_dev *chip)
 418 {
 419         u32 alrm_val = 0;
 420         u32 alrm_irq_val = 0;
 421         u32 alrm_wake_val = 0;
 422         unsigned long flags;
 423
 424         if (to) {
 425                 alrm_val = SUN6I_ALRM_EN_CNT_EN;
 426                 alrm_irq_val = SUN6I_ALRM_IRQ_EN_CNT_IRQ_EN;
 427                 alrm_wake_val = SUN6I_ALARM_CONFIG_WAKEUP;
 428         } else {
 429                 writel(SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND,
 430                        chip->base + SUN6I_ALRM_IRQ_STA);
 431         }
 432
 433         spin_lock_irqsave(&chip->lock, flags);
 434         writel(alrm_val, chip->base + SUN6I_ALRM_EN);
 435         writel(alrm_irq_val, chip->base + SUN6I_ALRM_IRQ_EN);
 436         writel(alrm_wake_val, chip->base + SUN6I_ALARM_CONFIG);
 437         spin_unlock_irqrestore(&chip->lock, flags);
 438 }
 439
 440 static int sun6i_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
 441 {
 442         struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
 443         u32 date, time;
 444
 445         /*
 446          * read again in case it changes
 447          */
 448         do {
 449                 date = readl(chip->base + SUN6I_RTC_YMD);
 450                 time = readl(chip->base + SUN6I_RTC_HMS);
 451         } while ((date != readl(chip->base + SUN6I_RTC_YMD)) ||
 452                  (time != readl(chip->base + SUN6I_RTC_HMS)));
 453
 454         rtc_tm->tm_sec  = SUN6I_TIME_GET_SEC_VALUE(time);
 455         rtc_tm->tm_min  = SUN6I_TIME_GET_MIN_VALUE(time);
 456         rtc_tm->tm_hour = SUN6I_TIME_GET_HOUR_VALUE(time);
 457
 458         rtc_tm->tm_mday = SUN6I_DATE_GET_DAY_VALUE(date);
 459         rtc_tm->tm_mon  = SUN6I_DATE_GET_MON_VALUE(date);
 460         rtc_tm->tm_year = SUN6I_DATE_GET_YEAR_VALUE(date);
 461
 462         rtc_tm->tm_mon  -= 1;
 463
 464         /*
 465          * switch from (data_year->min)-relative offset to
 466          * a (1900)-relative one
 467          */
 468         rtc_tm->tm_year += SUN6I_YEAR_OFF;
 469
 470         return 0;
 471 }
 472
 473 static int sun6i_rtc_getalarm(struct device *dev, struct rtc_wkalrm *wkalrm)
 474 {
 475         struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
 476         unsigned long flags;
 477         u32 alrm_st;
 478         u32 alrm_en;
 479
 480         spin_lock_irqsave(&chip->lock, flags);
 481         alrm_en = readl(chip->base + SUN6I_ALRM_IRQ_EN);
 482         alrm_st = readl(chip->base + SUN6I_ALRM_IRQ_STA);
 483         spin_unlock_irqrestore(&chip->lock, flags);
 484
 485         wkalrm->enabled = !!(alrm_en & SUN6I_ALRM_EN_CNT_EN);
 486         wkalrm->pending = !!(alrm_st & SUN6I_ALRM_EN_CNT_EN);
 487         rtc_time_to_tm(chip->alarm, &wkalrm->time);
 488
 489         return 0;
 490 }
 491
 492 static int sun6i_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm)
 493 {
 494         struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
 495         struct rtc_time *alrm_tm = &wkalrm->time;
 496         struct rtc_time tm_now;
 497         unsigned long time_now = 0;
 498         unsigned long time_set = 0;
 499         unsigned long time_gap = 0;
 500         int ret = 0;
 501
 502         ret = sun6i_rtc_gettime(dev, &tm_now);
 503         if (ret < 0) {
 504                 dev_err(dev, "Error in getting time\n");
 505                 return -EINVAL;
 506         }
 507
 508         rtc_tm_to_time(alrm_tm, &time_set);
 509         rtc_tm_to_time(&tm_now, &time_now);
 510         if (time_set <= time_now) {
 511                 dev_err(dev, "Date to set in the past\n");
 512                 return -EINVAL;
 513         }
 514
 515         time_gap = time_set - time_now;
 516
 517         if (time_gap > U32_MAX) {
 518                 dev_err(dev, "Date too far in the future\n");
 519                 return -EINVAL;
 520         }
 521
 522         sun6i_rtc_setaie(0, chip);
 523         writel(0, chip->base + SUN6I_ALRM_COUNTER);
 524         usleep_range(100, 300);
 525
 526         writel(time_gap, chip->base + SUN6I_ALRM_COUNTER);
 527         chip->alarm = time_set;
 528
 529         sun6i_rtc_setaie(wkalrm->enabled, chip);
 530
 531         return 0;
 532 }
 533
 534 static int sun6i_rtc_wait(struct sun6i_rtc_dev *chip, int offset,
 535                           unsigned int mask, unsigned int ms_timeout)
 536 {
 537         const unsigned long timeout = jiffies + msecs_to_jiffies(ms_timeout);
 538         u32 reg;
 539
 540         do {
 541                 reg = readl(chip->base + offset);
 542                 reg &= mask;
 543
 544                 if (!reg)
 545                         return 0;
 546
 547         } while (time_before(jiffies, timeout));
 548
 549         return -ETIMEDOUT;
 550 }
 551
 552 static int sun6i_rtc_settime(struct device *dev, struct rtc_time *rtc_tm)
 553 {
 554         struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
 555         u32 date = 0;
 556         u32 time = 0;
 557         int year;
 558
 559         year = rtc_tm->tm_year + 1900;
 560         if (year < SUN6I_YEAR_MIN || year > SUN6I_YEAR_MAX) {
 561                 dev_err(dev, "rtc only supports year in range %d - %d\n",
 562                         SUN6I_YEAR_MIN, SUN6I_YEAR_MAX);
 563                 return -EINVAL;
 564         }
 565
 566         rtc_tm->tm_year -= SUN6I_YEAR_OFF;
 567         rtc_tm->tm_mon += 1;
 568
 569         date = SUN6I_DATE_SET_DAY_VALUE(rtc_tm->tm_mday) |
 570                 SUN6I_DATE_SET_MON_VALUE(rtc_tm->tm_mon)  |
 571                 SUN6I_DATE_SET_YEAR_VALUE(rtc_tm->tm_year);
 572
 573         if (is_leap_year(year))
 574                 date |= SUN6I_LEAP_SET_VALUE(1);
 575
 576         time = SUN6I_TIME_SET_SEC_VALUE(rtc_tm->tm_sec)  |
 577                 SUN6I_TIME_SET_MIN_VALUE(rtc_tm->tm_min)  |
 578                 SUN6I_TIME_SET_HOUR_VALUE(rtc_tm->tm_hour);
 579
 580         /* Check whether registers are writable */
 581         if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,
 582                            SUN6I_LOSC_CTRL_ACC_MASK, 50)) {
 583                 dev_err(dev, "rtc is still busy.\n");
 584                 return -EBUSY;
 585         }
 586
 587         writel(time, chip->base + SUN6I_RTC_HMS);
 588
 589         /*
 590          * After writing the RTC HH-MM-SS register, the
 591          * SUN6I_LOSC_CTRL_RTC_HMS_ACC bit is set and it will not
 592          * be cleared until the real writing operation is finished
 593          */
 594
 595         if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,
 596                            SUN6I_LOSC_CTRL_RTC_HMS_ACC, 50)) {
 597                 dev_err(dev, "Failed to set rtc time.\n");
 598                 return -ETIMEDOUT;
 599         }
 600
 601         writel(date, chip->base + SUN6I_RTC_YMD);
 602
 603         /*
 604          * After writing the RTC YY-MM-DD register, the
 605          * SUN6I_LOSC_CTRL_RTC_YMD_ACC bit is set and it will not
 606          * be cleared until the real writing operation is finished
 607          */
 608
 609         if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,
 610                            SUN6I_LOSC_CTRL_RTC_YMD_ACC, 50)) {
 611                 dev_err(dev, "Failed to set rtc time.\n");
 612                 return -ETIMEDOUT;
 613         }
 614
 615         return 0;
 616 }
 617
 618 static int sun6i_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 619 {
 620         struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
 621
 622         if (!enabled)
 623                 sun6i_rtc_setaie(enabled, chip);
 624
 625         return 0;
 626 }
 627
 628 static const struct rtc_class_ops sun6i_rtc_ops = {
 629         .read_time              = sun6i_rtc_gettime,
 630         .set_time               = sun6i_rtc_settime,
 631         .read_alarm             = sun6i_rtc_getalarm,
 632         .set_alarm              = sun6i_rtc_setalarm,
 633         .alarm_irq_enable       = sun6i_rtc_alarm_irq_enable
 634 };
 635
 636 #ifdef CONFIG_PM_SLEEP
 637 /* Enable IRQ wake on suspend, to wake up from RTC. */
 638 static int sun6i_rtc_suspend(struct device *dev)
 639 {
 640         struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
 641
 642         if (device_may_wakeup(dev))
 643                 enable_irq_wake(chip->irq);
 644
 645         return 0;
 646 }
 647
 648 /* Disable IRQ wake on resume. */
 649 static int sun6i_rtc_resume(struct device *dev)
 650 {
 651         struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
 652
 653         if (device_may_wakeup(dev))
 654                 disable_irq_wake(chip->irq);
 655
 656         return 0;
 657 }
 658 #endif
 659
 660 static SIMPLE_DEV_PM_OPS(sun6i_rtc_pm_ops,
 661         sun6i_rtc_suspend, sun6i_rtc_resume);
 662
 663 static int sun6i_rtc_probe(struct platform_device *pdev)
 664 {
 665         struct sun6i_rtc_dev *chip = sun6i_rtc;
 666         int ret;
 667
 668         if (!chip)
 669                 return -ENODEV;
 670
 671         platform_set_drvdata(pdev, chip);
 672         chip->dev = &pdev->dev;
 673
 674         chip->irq = platform_get_irq(pdev, 0);
 675         if (chip->irq < 0)
 676                 return chip->irq;
 677
 678         ret = devm_request_irq(&pdev->dev, chip->irq, sun6i_rtc_alarmirq,
 679                                0, dev_name(&pdev->dev), chip);
 680         if (ret) {
 681                 dev_err(&pdev->dev, "Could not request IRQ\n");
 682                 return ret;
 683         }
 684
 685         /* clear the alarm counter value */
 686         writel(0, chip->base + SUN6I_ALRM_COUNTER);
 687
 688         /* disable counter alarm */
 689         writel(0, chip->base + SUN6I_ALRM_EN);
 690
 691         /* disable counter alarm interrupt */
 692         writel(0, chip->base + SUN6I_ALRM_IRQ_EN);
 693
 694         /* disable week alarm */
 695         writel(0, chip->base + SUN6I_ALRM1_EN);
 696
 697         /* disable week alarm interrupt */
 698         writel(0, chip->base + SUN6I_ALRM1_IRQ_EN);
 699
 700         /* clear counter alarm pending interrupts */
 701         writel(SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND,
 702                chip->base + SUN6I_ALRM_IRQ_STA);
 703
 704         /* clear week alarm pending interrupts */
 705         writel(SUN6I_ALRM1_IRQ_STA_WEEK_IRQ_PEND,
 706                chip->base + SUN6I_ALRM1_IRQ_STA);
 707
 708         /* disable alarm wakeup */
 709         writel(0, chip->base + SUN6I_ALARM_CONFIG);
 710
 711         clk_prepare_enable(chip->losc);
 712
 713         device_init_wakeup(&pdev->dev, 1);
 714
 715         chip->rtc = devm_rtc_device_register(&pdev->dev, "rtc-sun6i",
 716                                              &sun6i_rtc_ops, THIS_MODULE);
 717         if (IS_ERR(chip->rtc)) {
 718                 dev_err(&pdev->dev, "unable to register device\n");
 719                 return PTR_ERR(chip->rtc);
 720         }
 721
 722         dev_info(&pdev->dev, "RTC enabled\n");
 723
 724         return 0;
 725 }
 726
 727 /*
 728  * As far as RTC functionality goes, all models are the same. The
 729  * datasheets claim that different models have different number of
 730  * registers available for non-volatile storage, but experiments show
 731  * that all SoCs have 16 registers available for this purpose.
 732  */
 733 static const struct of_device_id sun6i_rtc_dt_ids[] = {
 734         { .compatible = "allwinner,sun6i-a31-rtc" },
 735         { .compatible = "allwinner,sun8i-a23-rtc" },
 736         { .compatible = "allwinner,sun8i-h3-rtc" },
 737         { .compatible = "allwinner,sun8i-r40-rtc" },
 738         { .compatible = "allwinner,sun8i-v3-rtc" },
 739         { .compatible = "allwinner,sun50i-h5-rtc" },
 740         { .compatible = "allwinner,sun50i-h6-rtc" },
 741         { /* sentinel */ },
 742 };
 743 MODULE_DEVICE_TABLE(of, sun6i_rtc_dt_ids);
 744
 745 static struct platform_driver sun6i_rtc_driver = {
 746         .probe          = sun6i_rtc_probe,
 747         .driver         = {
 748                 .name           = "sun6i-rtc",
 749                 .of_match_table = sun6i_rtc_dt_ids,
 750                 .pm = &sun6i_rtc_pm_ops,
 751         },
 752 };
 753 builtin_platform_driver(sun6i_rtc_driver);