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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * drivers/rtc/rtc-vt8500.c4 *5 * Copyright (C) 2010 Alexey Charkov <alchark@gmail.com>6 *7 * Based on rtc-pxa.c8 */9 10#include <linux/module.h>11#include <linux/rtc.h>12#include <linux/init.h>13#include <linux/interrupt.h>14#include <linux/io.h>15#include <linux/bcd.h>16#include <linux/platform_device.h>17#include <linux/slab.h>18#include <linux/of.h>19 20/*21 * Register definitions22 */23#define VT8500_RTC_TS 0x00 /* Time set */24#define VT8500_RTC_DS 0x04 /* Date set */25#define VT8500_RTC_AS 0x08 /* Alarm set */26#define VT8500_RTC_CR 0x0c /* Control */27#define VT8500_RTC_TR 0x10 /* Time read */28#define VT8500_RTC_DR 0x14 /* Date read */29#define VT8500_RTC_WS 0x18 /* Write status */30#define VT8500_RTC_CL 0x20 /* Calibration */31#define VT8500_RTC_IS 0x24 /* Interrupt status */32#define VT8500_RTC_ST 0x28 /* Status */33 34#define INVALID_TIME_BIT (1 << 31)35 36#define DATE_CENTURY_S 1937#define DATE_YEAR_S 1138#define DATE_YEAR_MASK (0xff << DATE_YEAR_S)39#define DATE_MONTH_S 640#define DATE_MONTH_MASK (0x1f << DATE_MONTH_S)41#define DATE_DAY_MASK 0x3f42 43#define TIME_DOW_S 2044#define TIME_DOW_MASK (0x07 << TIME_DOW_S)45#define TIME_HOUR_S 1446#define TIME_HOUR_MASK (0x3f << TIME_HOUR_S)47#define TIME_MIN_S 748#define TIME_MIN_MASK (0x7f << TIME_MIN_S)49#define TIME_SEC_MASK 0x7f50 51#define ALARM_DAY_S 2052#define ALARM_DAY_MASK (0x3f << ALARM_DAY_S)53 54#define ALARM_DAY_BIT (1 << 29)55#define ALARM_HOUR_BIT (1 << 28)56#define ALARM_MIN_BIT (1 << 27)57#define ALARM_SEC_BIT (1 << 26)58 59#define ALARM_ENABLE_MASK (ALARM_DAY_BIT \60 | ALARM_HOUR_BIT \61 | ALARM_MIN_BIT \62 | ALARM_SEC_BIT)63 64#define VT8500_RTC_CR_ENABLE (1 << 0) /* Enable RTC */65#define VT8500_RTC_CR_12H (1 << 1) /* 12h time format */66#define VT8500_RTC_CR_SM_ENABLE (1 << 2) /* Enable periodic irqs */67#define VT8500_RTC_CR_SM_SEC (1 << 3) /* 0: 1Hz/60, 1: 1Hz */68#define VT8500_RTC_CR_CALIB (1 << 4) /* Enable calibration */69 70#define VT8500_RTC_IS_ALARM (1 << 0) /* Alarm interrupt status */71 72struct vt8500_rtc {73 void __iomem *regbase;74 int irq_alarm;75 struct rtc_device *rtc;76 spinlock_t lock; /* Protects this structure */77};78 79static irqreturn_t vt8500_rtc_irq(int irq, void *dev_id)80{81 struct vt8500_rtc *vt8500_rtc = dev_id;82 u32 isr;83 unsigned long events = 0;84 85 spin_lock(&vt8500_rtc->lock);86 87 /* clear interrupt sources */88 isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS);89 writel(isr, vt8500_rtc->regbase + VT8500_RTC_IS);90 91 spin_unlock(&vt8500_rtc->lock);92 93 if (isr & VT8500_RTC_IS_ALARM)94 events |= RTC_AF | RTC_IRQF;95 96 rtc_update_irq(vt8500_rtc->rtc, 1, events);97 98 return IRQ_HANDLED;99}100 101static int vt8500_rtc_read_time(struct device *dev, struct rtc_time *tm)102{103 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);104 u32 date, time;105 106 date = readl(vt8500_rtc->regbase + VT8500_RTC_DR);107 time = readl(vt8500_rtc->regbase + VT8500_RTC_TR);108 109 tm->tm_sec = bcd2bin(time & TIME_SEC_MASK);110 tm->tm_min = bcd2bin((time & TIME_MIN_MASK) >> TIME_MIN_S);111 tm->tm_hour = bcd2bin((time & TIME_HOUR_MASK) >> TIME_HOUR_S);112 tm->tm_mday = bcd2bin(date & DATE_DAY_MASK);113 tm->tm_mon = bcd2bin((date & DATE_MONTH_MASK) >> DATE_MONTH_S) - 1;114 tm->tm_year = bcd2bin((date & DATE_YEAR_MASK) >> DATE_YEAR_S)115 + ((date >> DATE_CENTURY_S) & 1 ? 200 : 100);116 tm->tm_wday = (time & TIME_DOW_MASK) >> TIME_DOW_S;117 118 return 0;119}120 121static int vt8500_rtc_set_time(struct device *dev, struct rtc_time *tm)122{123 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);124 125 writel((bin2bcd(tm->tm_year % 100) << DATE_YEAR_S)126 | (bin2bcd(tm->tm_mon + 1) << DATE_MONTH_S)127 | (bin2bcd(tm->tm_mday))128 | ((tm->tm_year >= 200) << DATE_CENTURY_S),129 vt8500_rtc->regbase + VT8500_RTC_DS);130 writel((bin2bcd(tm->tm_wday) << TIME_DOW_S)131 | (bin2bcd(tm->tm_hour) << TIME_HOUR_S)132 | (bin2bcd(tm->tm_min) << TIME_MIN_S)133 | (bin2bcd(tm->tm_sec)),134 vt8500_rtc->regbase + VT8500_RTC_TS);135 136 return 0;137}138 139static int vt8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)140{141 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);142 u32 isr, alarm;143 144 alarm = readl(vt8500_rtc->regbase + VT8500_RTC_AS);145 isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS);146 147 alrm->time.tm_mday = bcd2bin((alarm & ALARM_DAY_MASK) >> ALARM_DAY_S);148 alrm->time.tm_hour = bcd2bin((alarm & TIME_HOUR_MASK) >> TIME_HOUR_S);149 alrm->time.tm_min = bcd2bin((alarm & TIME_MIN_MASK) >> TIME_MIN_S);150 alrm->time.tm_sec = bcd2bin((alarm & TIME_SEC_MASK));151 152 alrm->enabled = (alarm & ALARM_ENABLE_MASK) ? 1 : 0;153 alrm->pending = (isr & VT8500_RTC_IS_ALARM) ? 1 : 0;154 155 return rtc_valid_tm(&alrm->time);156}157 158static int vt8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)159{160 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);161 162 writel((alrm->enabled ? ALARM_ENABLE_MASK : 0)163 | (bin2bcd(alrm->time.tm_mday) << ALARM_DAY_S)164 | (bin2bcd(alrm->time.tm_hour) << TIME_HOUR_S)165 | (bin2bcd(alrm->time.tm_min) << TIME_MIN_S)166 | (bin2bcd(alrm->time.tm_sec)),167 vt8500_rtc->regbase + VT8500_RTC_AS);168 169 return 0;170}171 172static int vt8500_alarm_irq_enable(struct device *dev, unsigned int enabled)173{174 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);175 unsigned long tmp = readl(vt8500_rtc->regbase + VT8500_RTC_AS);176 177 if (enabled)178 tmp |= ALARM_ENABLE_MASK;179 else180 tmp &= ~ALARM_ENABLE_MASK;181 182 writel(tmp, vt8500_rtc->regbase + VT8500_RTC_AS);183 return 0;184}185 186static const struct rtc_class_ops vt8500_rtc_ops = {187 .read_time = vt8500_rtc_read_time,188 .set_time = vt8500_rtc_set_time,189 .read_alarm = vt8500_rtc_read_alarm,190 .set_alarm = vt8500_rtc_set_alarm,191 .alarm_irq_enable = vt8500_alarm_irq_enable,192};193 194static int vt8500_rtc_probe(struct platform_device *pdev)195{196 struct vt8500_rtc *vt8500_rtc;197 int ret;198 199 vt8500_rtc = devm_kzalloc(&pdev->dev,200 sizeof(struct vt8500_rtc), GFP_KERNEL);201 if (!vt8500_rtc)202 return -ENOMEM;203 204 spin_lock_init(&vt8500_rtc->lock);205 platform_set_drvdata(pdev, vt8500_rtc);206 207 vt8500_rtc->irq_alarm = platform_get_irq(pdev, 0);208 if (vt8500_rtc->irq_alarm < 0)209 return vt8500_rtc->irq_alarm;210 211 vt8500_rtc->regbase = devm_platform_ioremap_resource(pdev, 0);212 if (IS_ERR(vt8500_rtc->regbase))213 return PTR_ERR(vt8500_rtc->regbase);214 215 /* Enable RTC and set it to 24-hour mode */216 writel(VT8500_RTC_CR_ENABLE,217 vt8500_rtc->regbase + VT8500_RTC_CR);218 219 vt8500_rtc->rtc = devm_rtc_allocate_device(&pdev->dev);220 if (IS_ERR(vt8500_rtc->rtc))221 return PTR_ERR(vt8500_rtc->rtc);222 223 vt8500_rtc->rtc->ops = &vt8500_rtc_ops;224 vt8500_rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;225 vt8500_rtc->rtc->range_max = RTC_TIMESTAMP_END_2199;226 227 ret = devm_request_irq(&pdev->dev, vt8500_rtc->irq_alarm,228 vt8500_rtc_irq, 0, "rtc alarm", vt8500_rtc);229 if (ret < 0) {230 dev_err(&pdev->dev, "can't get irq %i, err %d\n",231 vt8500_rtc->irq_alarm, ret);232 return ret;233 }234 235 return devm_rtc_register_device(vt8500_rtc->rtc);236}237 238static void vt8500_rtc_remove(struct platform_device *pdev)239{240 struct vt8500_rtc *vt8500_rtc = platform_get_drvdata(pdev);241 242 /* Disable alarm matching */243 writel(0, vt8500_rtc->regbase + VT8500_RTC_IS);244}245 246static const struct of_device_id wmt_dt_ids[] = {247 { .compatible = "via,vt8500-rtc", },248 {}249};250MODULE_DEVICE_TABLE(of, wmt_dt_ids);251 252static struct platform_driver vt8500_rtc_driver = {253 .probe = vt8500_rtc_probe,254 .remove_new = vt8500_rtc_remove,255 .driver = {256 .name = "vt8500-rtc",257 .of_match_table = wmt_dt_ids,258 },259};260 261module_platform_driver(vt8500_rtc_driver);262 263MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");264MODULE_DESCRIPTION("VIA VT8500 SoC Realtime Clock Driver (RTC)");265MODULE_LICENSE("GPL v2");266MODULE_ALIAS("platform:vt8500-rtc");267