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 25struct 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 60static 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 71static 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 */ 86static 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 109static 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 = (buf[1] << 24) | (buf[3] << 16) | (buf[5] << 8) | buf[7]; 119 120 /* load 32-bit read-only counter */ 121 pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf); 122 data = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0]; 123 ticks = base + data; 124 dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n", 125 base, data, ticks); 126 127 rtc_time_to_tm(ticks, tm); 128 129 return 0; 130} 131 132static int pm860x_rtc_set_time(struct device *dev, struct rtc_time *tm) 133{ 134 struct pm860x_rtc_info *info = dev_get_drvdata(dev); 135 unsigned char buf[4]; 136 unsigned long ticks, base, data; 137 138 if ((tm->tm_year < 70) || (tm->tm_year > 138)) { 139 dev_dbg(info->dev, "Set time %d out of range. " 140 "Please set time between 1970 to 2038.\n", 141 1900 + tm->tm_year); 142 return -EINVAL; 143 } 144 rtc_tm_to_time(tm, &ticks); 145 146 /* load 32-bit read-only counter */ 147 pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf); 148 data = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0]; 149 base = ticks - data; 150 dev_dbg(info->dev, "set base:0x%lx, RO count:0x%lx, ticks:0x%lx\n", 151 base, data, ticks); 152 153 pm860x_page_reg_write(info->i2c, REG0_DATA, (base >> 24) & 0xFF); 154 pm860x_page_reg_write(info->i2c, REG1_DATA, (base >> 16) & 0xFF); 155 pm860x_page_reg_write(info->i2c, REG2_DATA, (base >> 8) & 0xFF); 156 pm860x_page_reg_write(info->i2c, REG3_DATA, base & 0xFF); 157 158 if (info->sync) 159 info->sync(ticks); 160 return 0; 161} 162 163static int pm860x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 164{ 165 struct pm860x_rtc_info *info = dev_get_drvdata(dev); 166 unsigned char buf[8]; 167 unsigned long ticks, base, data; 168 int ret; 169 170 pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf); 171 dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1], 172 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]); 173 base = (buf[1] << 24) | (buf[3] << 16) | (buf[5] << 8) | buf[7]; 174 175 pm860x_bulk_read(info->i2c, PM8607_RTC_EXPIRE1, 4, buf); 176 data = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0]; 177 ticks = base + data; 178 dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n", 179 base, data, ticks); 180 181 rtc_time_to_tm(ticks, &alrm->time); 182 ret = pm860x_reg_read(info->i2c, PM8607_RTC1); 183 alrm->enabled = (ret & ALARM_EN) ? 1 : 0; 184 alrm->pending = (ret & (ALARM | ALARM_WAKEUP)) ? 1 : 0; 185 return 0; 186} 187 188static int pm860x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 189{ 190 struct pm860x_rtc_info *info = dev_get_drvdata(dev); 191 struct rtc_time now_tm, alarm_tm; 192 unsigned long ticks, base, data; 193 unsigned char buf[8]; 194 int mask; 195 196 pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0); 197 198 pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf); 199 dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1], 200 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]); 201 base = (buf[1] << 24) | (buf[3] << 16) | (buf[5] << 8) | buf[7]; 202 203 /* load 32-bit read-only counter */ 204 pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf); 205 data = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0]; 206 ticks = base + data; 207 dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n", 208 base, data, ticks); 209 210 rtc_time_to_tm(ticks, &now_tm); 211 rtc_next_alarm_time(&alarm_tm, &now_tm, &alrm->time); 212 /* get new ticks for alarm in 24 hours */ 213 rtc_tm_to_time(&alarm_tm, &ticks); 214 data = ticks - base; 215 216 buf[0] = data & 0xff; 217 buf[1] = (data >> 8) & 0xff; 218 buf[2] = (data >> 16) & 0xff; 219 buf[3] = (data >> 24) & 0xff; 220 pm860x_bulk_write(info->i2c, PM8607_RTC_EXPIRE1, 4, buf); 221 if (alrm->enabled) { 222 mask = ALARM | ALARM_WAKEUP | ALARM_EN; 223 pm860x_set_bits(info->i2c, PM8607_RTC1, mask, mask); 224 } else { 225 mask = ALARM | ALARM_WAKEUP | ALARM_EN; 226 pm860x_set_bits(info->i2c, PM8607_RTC1, mask, 227 ALARM | ALARM_WAKEUP); 228 } 229 return 0; 230} 231 232static const struct rtc_class_ops pm860x_rtc_ops = { 233 .read_time = pm860x_rtc_read_time, 234 .set_time = pm860x_rtc_set_time, 235 .read_alarm = pm860x_rtc_read_alarm, 236 .set_alarm = pm860x_rtc_set_alarm, 237 .alarm_irq_enable = pm860x_rtc_alarm_irq_enable, 238}; 239 240#ifdef VRTC_CALIBRATION 241static void calibrate_vrtc_work(struct work_struct *work) 242{ 243 struct pm860x_rtc_info *info = container_of(work, 244 struct pm860x_rtc_info, calib_work.work); 245 unsigned char buf[2]; 246 unsigned int sum, data, mean, vrtc_set; 247 int i; 248 249 for (i = 0, sum = 0; i < 16; i++) { 250 msleep(100); 251 pm860x_bulk_read(info->i2c, REG_VRTC_MEAS1, 2, buf); 252 data = (buf[0] << 4) | buf[1]; 253 data = (data * 5400) >> 12; /* convert to mv */ 254 sum += data; 255 } 256 mean = sum >> 4; 257 vrtc_set = 2700 + (info->vrtc & 0x3) * 200; 258 dev_dbg(info->dev, "mean:%d, vrtc_set:%d\n", mean, vrtc_set); 259 260 sum = pm860x_reg_read(info->i2c, PM8607_RTC_MISC1); 261 data = sum & 0x3; 262 if ((mean + 200) < vrtc_set) { 263 /* try higher voltage */ 264 if (++data == 4) 265 goto out; 266 data = (sum & 0xf8) | (data & 0x3); 267 pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data); 268 } else if ((mean - 200) > vrtc_set) { 269 /* try lower voltage */ 270 if (data-- == 0) 271 goto out; 272 data = (sum & 0xf8) | (data & 0x3); 273 pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data); 274 } else 275 goto out; 276 dev_dbg(info->dev, "set 0x%x to RTC_MISC1\n", data); 277 /* trigger next calibration since VRTC is updated */ 278 schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL); 279 return; 280out: 281 /* disable measurement */ 282 pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0); 283 dev_dbg(info->dev, "finish VRTC calibration\n"); 284 return; 285} 286#endif 287 288#ifdef CONFIG_OF 289static int pm860x_rtc_dt_init(struct platform_device *pdev, 290 struct pm860x_rtc_info *info) 291{ 292 struct device_node *np = pdev->dev.parent->of_node; 293 int ret; 294 if (!np) 295 return -ENODEV; 296 np = of_get_child_by_name(np, "rtc"); 297 if (!np) { 298 dev_err(&pdev->dev, "failed to find rtc node\n"); 299 return -ENODEV; 300 } 301 ret = of_property_read_u32(np, "marvell,88pm860x-vrtc", &info->vrtc); 302 if (ret) 303 info->vrtc = 0; 304 of_node_put(np); 305 return 0; 306} 307#else 308#define pm860x_rtc_dt_init(x, y) (-1) 309#endif 310 311static int pm860x_rtc_probe(struct platform_device *pdev) 312{ 313 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent); 314 struct pm860x_rtc_pdata *pdata = NULL; 315 struct pm860x_rtc_info *info; 316 struct rtc_time tm; 317 unsigned long ticks = 0; 318 int ret; 319 320 pdata = dev_get_platdata(&pdev->dev); 321 322 info = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_rtc_info), 323 GFP_KERNEL); 324 if (!info) 325 return -ENOMEM; 326 info->irq = platform_get_irq(pdev, 0); 327 if (info->irq < 0) { 328 dev_err(&pdev->dev, "No IRQ resource!\n"); 329 return info->irq; 330 } 331 332 info->chip = chip; 333 info->i2c = (chip->id == CHIP_PM8607) ? chip->client : chip->companion; 334 info->dev = &pdev->dev; 335 dev_set_drvdata(&pdev->dev, info); 336 337 ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL, 338 rtc_update_handler, IRQF_ONESHOT, "rtc", 339 info); 340 if (ret < 0) { 341 dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n", 342 info->irq, ret); 343 return ret; 344 } 345 346 /* set addresses of 32-bit base value for RTC time */ 347 pm860x_page_reg_write(info->i2c, REG0_ADDR, REG0_DATA); 348 pm860x_page_reg_write(info->i2c, REG1_ADDR, REG1_DATA); 349 pm860x_page_reg_write(info->i2c, REG2_ADDR, REG2_DATA); 350 pm860x_page_reg_write(info->i2c, REG3_ADDR, REG3_DATA); 351 352 ret = pm860x_rtc_read_time(&pdev->dev, &tm); 353 if (ret < 0) { 354 dev_err(&pdev->dev, "Failed to read initial time.\n"); 355 return ret; 356 } 357 if ((tm.tm_year < 70) || (tm.tm_year > 138)) { 358 tm.tm_year = 70; 359 tm.tm_mon = 0; 360 tm.tm_mday = 1; 361 tm.tm_hour = 0; 362 tm.tm_min = 0; 363 tm.tm_sec = 0; 364 ret = pm860x_rtc_set_time(&pdev->dev, &tm); 365 if (ret < 0) { 366 dev_err(&pdev->dev, "Failed to set initial time.\n"); 367 return ret; 368 } 369 } 370 rtc_tm_to_time(&tm, &ticks); 371 if (pm860x_rtc_dt_init(pdev, info)) { 372 if (pdata && pdata->sync) { 373 pdata->sync(ticks); 374 info->sync = pdata->sync; 375 } 376 } 377 378 info->rtc_dev = devm_rtc_device_register(&pdev->dev, "88pm860x-rtc", 379 &pm860x_rtc_ops, THIS_MODULE); 380 ret = PTR_ERR(info->rtc_dev); 381 if (IS_ERR(info->rtc_dev)) { 382 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret); 383 return ret; 384 } 385 386 /* 387 * enable internal XO instead of internal 3.25MHz clock since it can 388 * free running in PMIC power-down state. 389 */ 390 pm860x_set_bits(info->i2c, PM8607_RTC1, RTC1_USE_XO, RTC1_USE_XO); 391 392#ifdef VRTC_CALIBRATION 393 /* <00> -- 2.7V, <01> -- 2.9V, <10> -- 3.1V, <11> -- 3.3V */ 394 if (pm860x_rtc_dt_init(pdev, info)) { 395 if (pdata && pdata->vrtc) 396 info->vrtc = pdata->vrtc & 0x3; 397 else 398 info->vrtc = 1; 399 } 400 pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, MEAS2_VRTC); 401 402 /* calibrate VRTC */ 403 INIT_DELAYED_WORK(&info->calib_work, calibrate_vrtc_work); 404 schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL); 405#endif /* VRTC_CALIBRATION */ 406 407 device_init_wakeup(&pdev->dev, 1); 408 409 return 0; 410} 411 412static int pm860x_rtc_remove(struct platform_device *pdev) 413{ 414 struct pm860x_rtc_info *info = platform_get_drvdata(pdev); 415 416#ifdef VRTC_CALIBRATION 417 flush_scheduled_work(); 418 /* disable measurement */ 419 pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0); 420#endif /* VRTC_CALIBRATION */ 421 422 return 0; 423} 424 425#ifdef CONFIG_PM_SLEEP 426static int pm860x_rtc_suspend(struct device *dev) 427{ 428 struct platform_device *pdev = to_platform_device(dev); 429 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent); 430 431 if (device_may_wakeup(dev)) 432 chip->wakeup_flag |= 1 << PM8607_IRQ_RTC; 433 return 0; 434} 435static int pm860x_rtc_resume(struct device *dev) 436{ 437 struct platform_device *pdev = to_platform_device(dev); 438 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent); 439 440 if (device_may_wakeup(dev)) 441 chip->wakeup_flag &= ~(1 << PM8607_IRQ_RTC); 442 return 0; 443} 444#endif 445 446static SIMPLE_DEV_PM_OPS(pm860x_rtc_pm_ops, pm860x_rtc_suspend, pm860x_rtc_resume); 447 448static struct platform_driver pm860x_rtc_driver = { 449 .driver = { 450 .name = "88pm860x-rtc", 451 .pm = &pm860x_rtc_pm_ops, 452 }, 453 .probe = pm860x_rtc_probe, 454 .remove = pm860x_rtc_remove, 455}; 456 457module_platform_driver(pm860x_rtc_driver); 458 459MODULE_DESCRIPTION("Marvell 88PM860x RTC driver"); 460MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>"); 461MODULE_LICENSE("GPL"); 462