1 /* 2 * Real Time Clock driver for Marvell 88PM860x PMIC 3 * 4 * Copyright (c) 2010 Marvell International Ltd. 5 * Author: Haojian Zhuang <haojian.zhuang@marvell.com> 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 */ 11 12 #include <linux/kernel.h> 13 #include <linux/module.h> 14 #include <linux/of.h> 15 #include <linux/platform_device.h> 16 #include <linux/slab.h> 17 #include <linux/mutex.h> 18 #include <linux/rtc.h> 19 #include <linux/delay.h> 20 #include <linux/mfd/core.h> 21 #include <linux/mfd/88pm860x.h> 22 23 #define VRTC_CALIBRATION 24 25 struct pm860x_rtc_info { 26 struct pm860x_chip *chip; 27 struct i2c_client *i2c; 28 struct rtc_device *rtc_dev; 29 struct device *dev; 30 struct delayed_work calib_work; 31 32 int irq; 33 int vrtc; 34 int (*sync)(unsigned int ticks); 35 }; 36 37 #define REG_VRTC_MEAS1 0x7D 38 39 #define REG0_ADDR 0xB0 40 #define REG1_ADDR 0xB2 41 #define REG2_ADDR 0xB4 42 #define REG3_ADDR 0xB6 43 44 #define REG0_DATA 0xB1 45 #define REG1_DATA 0xB3 46 #define REG2_DATA 0xB5 47 #define REG3_DATA 0xB7 48 49 /* bit definitions of Measurement Enable Register 2 (0x51) */ 50 #define MEAS2_VRTC (1 << 0) 51 52 /* bit definitions of RTC Register 1 (0xA0) */ 53 #define ALARM_EN (1 << 3) 54 #define ALARM_WAKEUP (1 << 4) 55 #define ALARM (1 << 5) 56 #define RTC1_USE_XO (1 << 7) 57 58 #define VRTC_CALIB_INTERVAL (HZ * 60 * 10) /* 10 minutes */ 59 60 static irqreturn_t rtc_update_handler(int irq, void *data) 61 { 62 struct pm860x_rtc_info *info = (struct pm860x_rtc_info *)data; 63 int mask; 64 65 mask = ALARM | ALARM_WAKEUP; 66 pm860x_set_bits(info->i2c, PM8607_RTC1, mask | ALARM_EN, mask); 67 rtc_update_irq(info->rtc_dev, 1, RTC_AF); 68 return IRQ_HANDLED; 69 } 70 71 static int pm860x_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) 72 { 73 struct pm860x_rtc_info *info = dev_get_drvdata(dev); 74 75 if (enabled) 76 pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, ALARM_EN); 77 else 78 pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0); 79 return 0; 80 } 81 82 /* 83 * Calculate the next alarm time given the requested alarm time mask 84 * and the current time. 85 */ 86 static void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now, 87 struct rtc_time *alrm) 88 { 89 unsigned long next_time; 90 unsigned long now_time; 91 92 next->tm_year = now->tm_year; 93 next->tm_mon = now->tm_mon; 94 next->tm_mday = now->tm_mday; 95 next->tm_hour = alrm->tm_hour; 96 next->tm_min = alrm->tm_min; 97 next->tm_sec = alrm->tm_sec; 98 99 rtc_tm_to_time(now, &now_time); 100 rtc_tm_to_time(next, &next_time); 101 102 if (next_time < now_time) { 103 /* Advance one day */ 104 next_time += 60 * 60 * 24; 105 rtc_time_to_tm(next_time, next); 106 } 107 } 108 109 static int pm860x_rtc_read_time(struct device *dev, struct rtc_time *tm) 110 { 111 struct pm860x_rtc_info *info = dev_get_drvdata(dev); 112 unsigned char buf[8]; 113 unsigned long ticks, base, data; 114 115 pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf); 116 dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1], 117 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]); 118 base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) | 119 (buf[5] << 8) | buf[7]; 120 121 /* load 32-bit read-only counter */ 122 pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf); 123 data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) | 124 (buf[1] << 8) | buf[0]; 125 ticks = base + data; 126 dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n", 127 base, data, ticks); 128 129 rtc_time_to_tm(ticks, tm); 130 131 return 0; 132 } 133 134 static int pm860x_rtc_set_time(struct device *dev, struct rtc_time *tm) 135 { 136 struct pm860x_rtc_info *info = dev_get_drvdata(dev); 137 unsigned char buf[4]; 138 unsigned long ticks, base, data; 139 140 if (tm->tm_year > 206) { 141 dev_dbg(info->dev, "Set time %d out of range. " 142 "Please set time between 1970 to 2106.\n", 143 1900 + tm->tm_year); 144 return -EINVAL; 145 } 146 rtc_tm_to_time(tm, &ticks); 147 148 /* load 32-bit read-only counter */ 149 pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf); 150 data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) | 151 (buf[1] << 8) | buf[0]; 152 base = ticks - data; 153 dev_dbg(info->dev, "set base:0x%lx, RO count:0x%lx, ticks:0x%lx\n", 154 base, data, ticks); 155 156 pm860x_page_reg_write(info->i2c, REG0_DATA, (base >> 24) & 0xFF); 157 pm860x_page_reg_write(info->i2c, REG1_DATA, (base >> 16) & 0xFF); 158 pm860x_page_reg_write(info->i2c, REG2_DATA, (base >> 8) & 0xFF); 159 pm860x_page_reg_write(info->i2c, REG3_DATA, base & 0xFF); 160 161 if (info->sync) 162 info->sync(ticks); 163 return 0; 164 } 165 166 static int pm860x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 167 { 168 struct pm860x_rtc_info *info = dev_get_drvdata(dev); 169 unsigned char buf[8]; 170 unsigned long ticks, base, data; 171 int ret; 172 173 pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf); 174 dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1], 175 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]); 176 base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) | 177 (buf[5] << 8) | buf[7]; 178 179 pm860x_bulk_read(info->i2c, PM8607_RTC_EXPIRE1, 4, buf); 180 data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) | 181 (buf[1] << 8) | buf[0]; 182 ticks = base + data; 183 dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n", 184 base, data, ticks); 185 186 rtc_time_to_tm(ticks, &alrm->time); 187 ret = pm860x_reg_read(info->i2c, PM8607_RTC1); 188 alrm->enabled = (ret & ALARM_EN) ? 1 : 0; 189 alrm->pending = (ret & (ALARM | ALARM_WAKEUP)) ? 1 : 0; 190 return 0; 191 } 192 193 static int pm860x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 194 { 195 struct pm860x_rtc_info *info = dev_get_drvdata(dev); 196 struct rtc_time now_tm, alarm_tm; 197 unsigned long ticks, base, data; 198 unsigned char buf[8]; 199 int mask; 200 201 pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0); 202 203 pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf); 204 dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1], 205 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]); 206 base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) | 207 (buf[5] << 8) | buf[7]; 208 209 /* load 32-bit read-only counter */ 210 pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf); 211 data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) | 212 (buf[1] << 8) | buf[0]; 213 ticks = base + data; 214 dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n", 215 base, data, ticks); 216 217 rtc_time_to_tm(ticks, &now_tm); 218 rtc_next_alarm_time(&alarm_tm, &now_tm, &alrm->time); 219 /* get new ticks for alarm in 24 hours */ 220 rtc_tm_to_time(&alarm_tm, &ticks); 221 data = ticks - base; 222 223 buf[0] = data & 0xff; 224 buf[1] = (data >> 8) & 0xff; 225 buf[2] = (data >> 16) & 0xff; 226 buf[3] = (data >> 24) & 0xff; 227 pm860x_bulk_write(info->i2c, PM8607_RTC_EXPIRE1, 4, buf); 228 if (alrm->enabled) { 229 mask = ALARM | ALARM_WAKEUP | ALARM_EN; 230 pm860x_set_bits(info->i2c, PM8607_RTC1, mask, mask); 231 } else { 232 mask = ALARM | ALARM_WAKEUP | ALARM_EN; 233 pm860x_set_bits(info->i2c, PM8607_RTC1, mask, 234 ALARM | ALARM_WAKEUP); 235 } 236 return 0; 237 } 238 239 static const struct rtc_class_ops pm860x_rtc_ops = { 240 .read_time = pm860x_rtc_read_time, 241 .set_time = pm860x_rtc_set_time, 242 .read_alarm = pm860x_rtc_read_alarm, 243 .set_alarm = pm860x_rtc_set_alarm, 244 .alarm_irq_enable = pm860x_rtc_alarm_irq_enable, 245 }; 246 247 #ifdef VRTC_CALIBRATION 248 static void calibrate_vrtc_work(struct work_struct *work) 249 { 250 struct pm860x_rtc_info *info = container_of(work, 251 struct pm860x_rtc_info, calib_work.work); 252 unsigned char buf[2]; 253 unsigned int sum, data, mean, vrtc_set; 254 int i; 255 256 for (i = 0, sum = 0; i < 16; i++) { 257 msleep(100); 258 pm860x_bulk_read(info->i2c, REG_VRTC_MEAS1, 2, buf); 259 data = (buf[0] << 4) | buf[1]; 260 data = (data * 5400) >> 12; /* convert to mv */ 261 sum += data; 262 } 263 mean = sum >> 4; 264 vrtc_set = 2700 + (info->vrtc & 0x3) * 200; 265 dev_dbg(info->dev, "mean:%d, vrtc_set:%d\n", mean, vrtc_set); 266 267 sum = pm860x_reg_read(info->i2c, PM8607_RTC_MISC1); 268 data = sum & 0x3; 269 if ((mean + 200) < vrtc_set) { 270 /* try higher voltage */ 271 if (++data == 4) 272 goto out; 273 data = (sum & 0xf8) | (data & 0x3); 274 pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data); 275 } else if ((mean - 200) > vrtc_set) { 276 /* try lower voltage */ 277 if (data-- == 0) 278 goto out; 279 data = (sum & 0xf8) | (data & 0x3); 280 pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data); 281 } else 282 goto out; 283 dev_dbg(info->dev, "set 0x%x to RTC_MISC1\n", data); 284 /* trigger next calibration since VRTC is updated */ 285 schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL); 286 return; 287 out: 288 /* disable measurement */ 289 pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0); 290 dev_dbg(info->dev, "finish VRTC calibration\n"); 291 return; 292 } 293 #endif 294 295 #ifdef CONFIG_OF 296 static int pm860x_rtc_dt_init(struct platform_device *pdev, 297 struct pm860x_rtc_info *info) 298 { 299 struct device_node *np = pdev->dev.parent->of_node; 300 int ret; 301 if (!np) 302 return -ENODEV; 303 np = of_get_child_by_name(np, "rtc"); 304 if (!np) { 305 dev_err(&pdev->dev, "failed to find rtc node\n"); 306 return -ENODEV; 307 } 308 ret = of_property_read_u32(np, "marvell,88pm860x-vrtc", &info->vrtc); 309 if (ret) 310 info->vrtc = 0; 311 of_node_put(np); 312 return 0; 313 } 314 #else 315 #define pm860x_rtc_dt_init(x, y) (-1) 316 #endif 317 318 static int pm860x_rtc_probe(struct platform_device *pdev) 319 { 320 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent); 321 struct pm860x_rtc_pdata *pdata = NULL; 322 struct pm860x_rtc_info *info; 323 struct rtc_time tm; 324 unsigned long ticks = 0; 325 int ret; 326 327 pdata = dev_get_platdata(&pdev->dev); 328 329 info = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_rtc_info), 330 GFP_KERNEL); 331 if (!info) 332 return -ENOMEM; 333 info->irq = platform_get_irq(pdev, 0); 334 if (info->irq < 0) { 335 dev_err(&pdev->dev, "No IRQ resource!\n"); 336 return info->irq; 337 } 338 339 info->chip = chip; 340 info->i2c = (chip->id == CHIP_PM8607) ? chip->client : chip->companion; 341 info->dev = &pdev->dev; 342 dev_set_drvdata(&pdev->dev, info); 343 344 ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL, 345 rtc_update_handler, IRQF_ONESHOT, "rtc", 346 info); 347 if (ret < 0) { 348 dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n", 349 info->irq, ret); 350 return ret; 351 } 352 353 /* set addresses of 32-bit base value for RTC time */ 354 pm860x_page_reg_write(info->i2c, REG0_ADDR, REG0_DATA); 355 pm860x_page_reg_write(info->i2c, REG1_ADDR, REG1_DATA); 356 pm860x_page_reg_write(info->i2c, REG2_ADDR, REG2_DATA); 357 pm860x_page_reg_write(info->i2c, REG3_ADDR, REG3_DATA); 358 359 ret = pm860x_rtc_read_time(&pdev->dev, &tm); 360 if (ret < 0) { 361 dev_err(&pdev->dev, "Failed to read initial time.\n"); 362 return ret; 363 } 364 if ((tm.tm_year < 70) || (tm.tm_year > 138)) { 365 tm.tm_year = 70; 366 tm.tm_mon = 0; 367 tm.tm_mday = 1; 368 tm.tm_hour = 0; 369 tm.tm_min = 0; 370 tm.tm_sec = 0; 371 ret = pm860x_rtc_set_time(&pdev->dev, &tm); 372 if (ret < 0) { 373 dev_err(&pdev->dev, "Failed to set initial time.\n"); 374 return ret; 375 } 376 } 377 rtc_tm_to_time(&tm, &ticks); 378 if (pm860x_rtc_dt_init(pdev, info)) { 379 if (pdata && pdata->sync) { 380 pdata->sync(ticks); 381 info->sync = pdata->sync; 382 } 383 } 384 385 info->rtc_dev = devm_rtc_device_register(&pdev->dev, "88pm860x-rtc", 386 &pm860x_rtc_ops, THIS_MODULE); 387 ret = PTR_ERR(info->rtc_dev); 388 if (IS_ERR(info->rtc_dev)) { 389 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret); 390 return ret; 391 } 392 393 /* 394 * enable internal XO instead of internal 3.25MHz clock since it can 395 * free running in PMIC power-down state. 396 */ 397 pm860x_set_bits(info->i2c, PM8607_RTC1, RTC1_USE_XO, RTC1_USE_XO); 398 399 #ifdef VRTC_CALIBRATION 400 /* <00> -- 2.7V, <01> -- 2.9V, <10> -- 3.1V, <11> -- 3.3V */ 401 if (pm860x_rtc_dt_init(pdev, info)) { 402 if (pdata && pdata->vrtc) 403 info->vrtc = pdata->vrtc & 0x3; 404 else 405 info->vrtc = 1; 406 } 407 pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, MEAS2_VRTC); 408 409 /* calibrate VRTC */ 410 INIT_DELAYED_WORK(&info->calib_work, calibrate_vrtc_work); 411 schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL); 412 #endif /* VRTC_CALIBRATION */ 413 414 device_init_wakeup(&pdev->dev, 1); 415 416 return 0; 417 } 418 419 static int pm860x_rtc_remove(struct platform_device *pdev) 420 { 421 struct pm860x_rtc_info *info = platform_get_drvdata(pdev); 422 423 #ifdef VRTC_CALIBRATION 424 flush_scheduled_work(); 425 /* disable measurement */ 426 pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0); 427 #endif /* VRTC_CALIBRATION */ 428 429 return 0; 430 } 431 432 #ifdef CONFIG_PM_SLEEP 433 static int pm860x_rtc_suspend(struct device *dev) 434 { 435 struct platform_device *pdev = to_platform_device(dev); 436 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent); 437 438 if (device_may_wakeup(dev)) 439 chip->wakeup_flag |= 1 << PM8607_IRQ_RTC; 440 return 0; 441 } 442 static int pm860x_rtc_resume(struct device *dev) 443 { 444 struct platform_device *pdev = to_platform_device(dev); 445 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent); 446 447 if (device_may_wakeup(dev)) 448 chip->wakeup_flag &= ~(1 << PM8607_IRQ_RTC); 449 return 0; 450 } 451 #endif 452 453 static SIMPLE_DEV_PM_OPS(pm860x_rtc_pm_ops, pm860x_rtc_suspend, pm860x_rtc_resume); 454 455 static struct platform_driver pm860x_rtc_driver = { 456 .driver = { 457 .name = "88pm860x-rtc", 458 .pm = &pm860x_rtc_pm_ops, 459 }, 460 .probe = pm860x_rtc_probe, 461 .remove = pm860x_rtc_remove, 462 }; 463 464 module_platform_driver(pm860x_rtc_driver); 465 466 MODULE_DESCRIPTION("Marvell 88PM860x RTC driver"); 467 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>"); 468 MODULE_LICENSE("GPL"); 469