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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Real Time Clock driver for Marvell 88PM860x PMIC4 *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_CALIBRATION21 22struct 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 0x7D34 35#define REG0_ADDR 0xB036#define REG1_ADDR 0xB237#define REG2_ADDR 0xB438#define REG3_ADDR 0xB639 40#define REG0_DATA 0xB141#define REG1_DATA 0xB342#define REG2_DATA 0xB543#define REG3_DATA 0xB744 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 56static 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 67static 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 else74 pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0);75 return 0;76}77 78static 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 103static 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 127static 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 154static 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 188static 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_CALIBRATION197static 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 } else231 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;236out: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#endif243 244#ifdef CONFIG_OF245static 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#else264#define pm860x_rtc_dt_init(x, y) do { } while (0)265#endif266 267static 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 can316 * 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_CALIBRATION321 /* <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 334static void pm860x_rtc_remove(struct platform_device *pdev)335{336 struct pm860x_rtc_info *info = platform_get_drvdata(pdev);337 338#ifdef VRTC_CALIBRATION339 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}344 345#ifdef CONFIG_PM_SLEEP346static int pm860x_rtc_suspend(struct device *dev)347{348 struct platform_device *pdev = to_platform_device(dev);349 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);350 351 if (device_may_wakeup(dev))352 chip->wakeup_flag |= 1 << PM8607_IRQ_RTC;353 return 0;354}355static int pm860x_rtc_resume(struct device *dev)356{357 struct platform_device *pdev = to_platform_device(dev);358 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);359 360 if (device_may_wakeup(dev))361 chip->wakeup_flag &= ~(1 << PM8607_IRQ_RTC);362 return 0;363}364#endif365 366static SIMPLE_DEV_PM_OPS(pm860x_rtc_pm_ops, pm860x_rtc_suspend, pm860x_rtc_resume);367 368static struct platform_driver pm860x_rtc_driver = {369 .driver = {370 .name = "88pm860x-rtc",371 .pm = &pm860x_rtc_pm_ops,372 },373 .probe = pm860x_rtc_probe,374 .remove_new = pm860x_rtc_remove,375};376 377module_platform_driver(pm860x_rtc_driver);378 379MODULE_DESCRIPTION("Marvell 88PM860x RTC driver");380MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");381MODULE_LICENSE("GPL");382