drivers/rtc/rtc-88pm860x.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Real Time Clock driver for Marvell 88PM860x PMIC
   4  *
   5  * Copyright (c) 2010 Marvell International Ltd.
   6  * Author:      Haojian Zhuang <haojian.zhuang@marvell.com>
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/module.h>
  11 #include <linux/of.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/slab.h>
  14 #include <linux/mutex.h>
  15 #include <linux/rtc.h>
  16 #include <linux/delay.h>
  17 #include <linux/mfd/core.h>
  18 #include <linux/mfd/88pm860x.h>
  19
  20 #define VRTC_CALIBRATION
  21
  22 struct pm860x_rtc_info {
  23         struct pm860x_chip      *chip;
  24         struct i2c_client       *i2c;
  25         struct rtc_device       *rtc_dev;
  26         struct device           *dev;
  27         struct delayed_work     calib_work;
  28
  29         int                     irq;
  30         int                     vrtc;
  31 };
  32
  33 #define REG_VRTC_MEAS1          0x7D
  34
  35 #define REG0_ADDR               0xB0
  36 #define REG1_ADDR               0xB2
  37 #define REG2_ADDR               0xB4
  38 #define REG3_ADDR               0xB6
  39
  40 #define REG0_DATA               0xB1
  41 #define REG1_DATA               0xB3
  42 #define REG2_DATA               0xB5
  43 #define REG3_DATA               0xB7
  44
  45 /* bit definitions of Measurement Enable Register 2 (0x51) */
  46 #define MEAS2_VRTC              (1 << 0)
  47
  48 /* bit definitions of RTC Register 1 (0xA0) */
  49 #define ALARM_EN                (1 << 3)
  50 #define ALARM_WAKEUP            (1 << 4)
  51 #define ALARM                   (1 << 5)
  52 #define RTC1_USE_XO             (1 << 7)
  53
  54 #define VRTC_CALIB_INTERVAL     (HZ * 60 * 10)          /* 10 minutes */
  55
  56 static irqreturn_t rtc_update_handler(int irq, void *data)
  57 {
  58         struct pm860x_rtc_info *info = (struct pm860x_rtc_info *)data;
  59         int mask;
  60
  61         mask = ALARM | ALARM_WAKEUP;
  62         pm860x_set_bits(info->i2c, PM8607_RTC1, mask | ALARM_EN, mask);
  63         rtc_update_irq(info->rtc_dev, 1, RTC_AF);
  64         return IRQ_HANDLED;
  65 }
  66
  67 static int pm860x_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
  68 {
  69         struct pm860x_rtc_info *info = dev_get_drvdata(dev);
  70
  71         if (enabled)
  72                 pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, ALARM_EN);
  73         else
  74                 pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0);
  75         return 0;
  76 }
  77
  78 static int pm860x_rtc_read_time(struct device *dev, struct rtc_time *tm)
  79 {
  80         struct pm860x_rtc_info *info = dev_get_drvdata(dev);
  81         unsigned char buf[8];
  82         unsigned long ticks, base, data;
  83
  84         pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
  85         dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
  86                 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
  87         base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) |
  88                 (buf[5] << 8) | buf[7];
  89
  90         /* load 32-bit read-only counter */
  91         pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
  92         data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) |
  93                 (buf[1] << 8) | buf[0];
  94         ticks = base + data;
  95         dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
  96                 base, data, ticks);
  97
  98         rtc_time64_to_tm(ticks, tm);
  99
 100         return 0;
 101 }
 102
 103 static int pm860x_rtc_set_time(struct device *dev, struct rtc_time *tm)
 104 {
 105         struct pm860x_rtc_info *info = dev_get_drvdata(dev);
 106         unsigned char buf[4];
 107         unsigned long ticks, base, data;
 108
 109         ticks = rtc_tm_to_time64(tm);
 110
 111         /* load 32-bit read-only counter */
 112         pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
 113         data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) |
 114                 (buf[1] << 8) | buf[0];
 115         base = ticks - data;
 116         dev_dbg(info->dev, "set base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
 117                 base, data, ticks);
 118
 119         pm860x_page_reg_write(info->i2c, REG0_DATA, (base >> 24) & 0xFF);
 120         pm860x_page_reg_write(info->i2c, REG1_DATA, (base >> 16) & 0xFF);
 121         pm860x_page_reg_write(info->i2c, REG2_DATA, (base >> 8) & 0xFF);
 122         pm860x_page_reg_write(info->i2c, REG3_DATA, base & 0xFF);
 123
 124         return 0;
 125 }
 126
 127 static int pm860x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 128 {
 129         struct pm860x_rtc_info *info = dev_get_drvdata(dev);
 130         unsigned char buf[8];
 131         unsigned long ticks, base, data;
 132         int ret;
 133
 134         pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
 135         dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
 136                 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
 137         base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) |
 138                 (buf[5] << 8) | buf[7];
 139
 140         pm860x_bulk_read(info->i2c, PM8607_RTC_EXPIRE1, 4, buf);
 141         data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) |
 142                 (buf[1] << 8) | buf[0];
 143         ticks = base + data;
 144         dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
 145                 base, data, ticks);
 146
 147         rtc_time64_to_tm(ticks, &alrm->time);
 148         ret = pm860x_reg_read(info->i2c, PM8607_RTC1);
 149         alrm->enabled = (ret & ALARM_EN) ? 1 : 0;
 150         alrm->pending = (ret & (ALARM | ALARM_WAKEUP)) ? 1 : 0;
 151         return 0;
 152 }
 153
 154 static int pm860x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 155 {
 156         struct pm860x_rtc_info *info = dev_get_drvdata(dev);
 157         unsigned long ticks, base, data;
 158         unsigned char buf[8];
 159         int mask;
 160
 161         pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0);
 162
 163         pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
 164         dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
 165                 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
 166         base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) |
 167                 (buf[5] << 8) | buf[7];
 168
 169         ticks = rtc_tm_to_time64(&alrm->time);
 170         data = ticks - base;
 171
 172         buf[0] = data & 0xff;
 173         buf[1] = (data >> 8) & 0xff;
 174         buf[2] = (data >> 16) & 0xff;
 175         buf[3] = (data >> 24) & 0xff;
 176         pm860x_bulk_write(info->i2c, PM8607_RTC_EXPIRE1, 4, buf);
 177         if (alrm->enabled) {
 178                 mask = ALARM | ALARM_WAKEUP | ALARM_EN;
 179                 pm860x_set_bits(info->i2c, PM8607_RTC1, mask, mask);
 180         } else {
 181                 mask = ALARM | ALARM_WAKEUP | ALARM_EN;
 182                 pm860x_set_bits(info->i2c, PM8607_RTC1, mask,
 183                                 ALARM | ALARM_WAKEUP);
 184         }
 185         return 0;
 186 }
 187
 188 static const struct rtc_class_ops pm860x_rtc_ops = {
 189         .read_time      = pm860x_rtc_read_time,
 190         .set_time       = pm860x_rtc_set_time,
 191         .read_alarm     = pm860x_rtc_read_alarm,
 192         .set_alarm      = pm860x_rtc_set_alarm,
 193         .alarm_irq_enable = pm860x_rtc_alarm_irq_enable,
 194 };
 195
 196 #ifdef VRTC_CALIBRATION
 197 static void calibrate_vrtc_work(struct work_struct *work)
 198 {
 199         struct pm860x_rtc_info *info = container_of(work,
 200                 struct pm860x_rtc_info, calib_work.work);
 201         unsigned char buf[2];
 202         unsigned int sum, data, mean, vrtc_set;
 203         int i;
 204
 205         for (i = 0, sum = 0; i < 16; i++) {
 206                 msleep(100);
 207                 pm860x_bulk_read(info->i2c, REG_VRTC_MEAS1, 2, buf);
 208                 data = (buf[0] << 4) | buf[1];
 209                 data = (data * 5400) >> 12;     /* convert to mv */
 210                 sum += data;
 211         }
 212         mean = sum >> 4;
 213         vrtc_set = 2700 + (info->vrtc & 0x3) * 200;
 214         dev_dbg(info->dev, "mean:%d, vrtc_set:%d\n", mean, vrtc_set);
 215
 216         sum = pm860x_reg_read(info->i2c, PM8607_RTC_MISC1);
 217         data = sum & 0x3;
 218         if ((mean + 200) < vrtc_set) {
 219                 /* try higher voltage */
 220                 if (++data == 4)
 221                         goto out;
 222                 data = (sum & 0xf8) | (data & 0x3);
 223                 pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data);
 224         } else if ((mean - 200) > vrtc_set) {
 225                 /* try lower voltage */
 226                 if (data-- == 0)
 227                         goto out;
 228                 data = (sum & 0xf8) | (data & 0x3);
 229                 pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data);
 230         } else
 231                 goto out;
 232         dev_dbg(info->dev, "set 0x%x to RTC_MISC1\n", data);
 233         /* trigger next calibration since VRTC is updated */
 234         schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL);
 235         return;
 236 out:
 237         /* disable measurement */
 238         pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0);
 239         dev_dbg(info->dev, "finish VRTC calibration\n");
 240         return;
 241 }
 242 #endif
 243
 244 #ifdef CONFIG_OF
 245 static int pm860x_rtc_dt_init(struct platform_device *pdev,
 246                               struct pm860x_rtc_info *info)
 247 {
 248         struct device_node *np = pdev->dev.parent->of_node;
 249         int ret;
 250         if (!np)
 251                 return -ENODEV;
 252         np = of_get_child_by_name(np, "rtc");
 253         if (!np) {
 254                 dev_err(&pdev->dev, "failed to find rtc node\n");
 255                 return -ENODEV;
 256         }
 257         ret = of_property_read_u32(np, "marvell,88pm860x-vrtc", &info->vrtc);
 258         if (ret)
 259                 info->vrtc = 0;
 260         of_node_put(np);
 261         return 0;
 262 }
 263 #else
 264 #define pm860x_rtc_dt_init(x, y)        do { } while (0)
 265 #endif
 266
 267 static int pm860x_rtc_probe(struct platform_device *pdev)
 268 {
 269         struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
 270         struct pm860x_rtc_info *info;
 271         int ret;
 272
 273         info = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_rtc_info),
 274                             GFP_KERNEL);
 275         if (!info)
 276                 return -ENOMEM;
 277         info->irq = platform_get_irq(pdev, 0);
 278         if (info->irq < 0)
 279                 return info->irq;
 280
 281         info->chip = chip;
 282         info->i2c = (chip->id == CHIP_PM8607) ? chip->client : chip->companion;
 283         info->dev = &pdev->dev;
 284         dev_set_drvdata(&pdev->dev, info);
 285
 286         info->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
 287         if (IS_ERR(info->rtc_dev))
 288                 return PTR_ERR(info->rtc_dev);
 289
 290         ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL,
 291                                         rtc_update_handler, IRQF_ONESHOT, "rtc",
 292                                         info);
 293         if (ret < 0) {
 294                 dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
 295                         info->irq, ret);
 296                 return ret;
 297         }
 298
 299         /* set addresses of 32-bit base value for RTC time */
 300         pm860x_page_reg_write(info->i2c, REG0_ADDR, REG0_DATA);
 301         pm860x_page_reg_write(info->i2c, REG1_ADDR, REG1_DATA);
 302         pm860x_page_reg_write(info->i2c, REG2_ADDR, REG2_DATA);
 303         pm860x_page_reg_write(info->i2c, REG3_ADDR, REG3_DATA);
 304
 305         pm860x_rtc_dt_init(pdev, info);
 306
 307         info->rtc_dev->ops = &pm860x_rtc_ops;
 308         info->rtc_dev->range_max = U32_MAX;
 309
 310         ret = devm_rtc_register_device(info->rtc_dev);
 311         if (ret)
 312                 return ret;
 313
 314         /*
 315          * enable internal XO instead of internal 3.25MHz clock since it can
 316          * free running in PMIC power-down state.
 317          */
 318         pm860x_set_bits(info->i2c, PM8607_RTC1, RTC1_USE_XO, RTC1_USE_XO);
 319
 320 #ifdef VRTC_CALIBRATION
 321         /* <00> -- 2.7V, <01> -- 2.9V, <10> -- 3.1V, <11> -- 3.3V */
 322         pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, MEAS2_VRTC);
 323
 324         /* calibrate VRTC */
 325         INIT_DELAYED_WORK(&info->calib_work, calibrate_vrtc_work);
 326         schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL);
 327 #endif  /* VRTC_CALIBRATION */
 328
 329         device_init_wakeup(&pdev->dev, 1);
 330
 331         return 0;
 332 }
 333
 334 static int pm860x_rtc_remove(struct platform_device *pdev)
 335 {
 336         struct pm860x_rtc_info *info = platform_get_drvdata(pdev);
 337
 338 #ifdef VRTC_CALIBRATION
 339         cancel_delayed_work_sync(&info->calib_work);
 340         /* disable measurement */
 341         pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0);
 342 #endif  /* VRTC_CALIBRATION */
 343
 344         return 0;
 345 }
 346
 347 #ifdef CONFIG_PM_SLEEP
 348 static int pm860x_rtc_suspend(struct device *dev)
 349 {
 350         struct platform_device *pdev = to_platform_device(dev);
 351         struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
 352
 353         if (device_may_wakeup(dev))
 354                 chip->wakeup_flag |= 1 << PM8607_IRQ_RTC;
 355         return 0;
 356 }
 357 static int pm860x_rtc_resume(struct device *dev)
 358 {
 359         struct platform_device *pdev = to_platform_device(dev);
 360         struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
 361
 362         if (device_may_wakeup(dev))
 363                 chip->wakeup_flag &= ~(1 << PM8607_IRQ_RTC);
 364         return 0;
 365 }
 366 #endif
 367
 368 static SIMPLE_DEV_PM_OPS(pm860x_rtc_pm_ops, pm860x_rtc_suspend, pm860x_rtc_resume);
 369
 370 static struct platform_driver pm860x_rtc_driver = {
 371         .driver         = {
 372                 .name   = "88pm860x-rtc",
 373                 .pm     = &pm860x_rtc_pm_ops,
 374         },
 375         .probe          = pm860x_rtc_probe,
 376         .remove         = pm860x_rtc_remove,
 377 };
 378
 379 module_platform_driver(pm860x_rtc_driver);
 380
 381 MODULE_DESCRIPTION("Marvell 88PM860x RTC driver");
 382 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
 383 MODULE_LICENSE("GPL");