1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * drivers/rtc/rtc-vt8500.c 4 * 5 * Copyright (C) 2010 Alexey Charkov <alchark@gmail.com> 6 * 7 * Based on rtc-pxa.c 8 */ 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 definitions 22 */ 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 19 37 #define DATE_YEAR_S 11 38 #define DATE_YEAR_MASK (0xff << DATE_YEAR_S) 39 #define DATE_MONTH_S 6 40 #define DATE_MONTH_MASK (0x1f << DATE_MONTH_S) 41 #define DATE_DAY_MASK 0x3f 42 43 #define TIME_DOW_S 20 44 #define TIME_DOW_MASK (0x07 << TIME_DOW_S) 45 #define TIME_HOUR_S 14 46 #define TIME_HOUR_MASK (0x3f << TIME_HOUR_S) 47 #define TIME_MIN_S 7 48 #define TIME_MIN_MASK (0x7f << TIME_MIN_S) 49 #define TIME_SEC_MASK 0x7f 50 51 #define ALARM_DAY_S 20 52 #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 72 struct vt8500_rtc { 73 void __iomem *regbase; 74 int irq_alarm; 75 struct rtc_device *rtc; 76 spinlock_t lock; /* Protects this structure */ 77 }; 78 79 static 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 } 100 101 static 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 } 120 121 static 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 if (tm->tm_year < 100) { 126 dev_warn(dev, "Only years 2000-2199 are supported by the " 127 "hardware!\n"); 128 return -EINVAL; 129 } 130 131 writel((bin2bcd(tm->tm_year % 100) << DATE_YEAR_S) 132 | (bin2bcd(tm->tm_mon + 1) << DATE_MONTH_S) 133 | (bin2bcd(tm->tm_mday)) 134 | ((tm->tm_year >= 200) << DATE_CENTURY_S), 135 vt8500_rtc->regbase + VT8500_RTC_DS); 136 writel((bin2bcd(tm->tm_wday) << TIME_DOW_S) 137 | (bin2bcd(tm->tm_hour) << TIME_HOUR_S) 138 | (bin2bcd(tm->tm_min) << TIME_MIN_S) 139 | (bin2bcd(tm->tm_sec)), 140 vt8500_rtc->regbase + VT8500_RTC_TS); 141 142 return 0; 143 } 144 145 static int vt8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 146 { 147 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); 148 u32 isr, alarm; 149 150 alarm = readl(vt8500_rtc->regbase + VT8500_RTC_AS); 151 isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS); 152 153 alrm->time.tm_mday = bcd2bin((alarm & ALARM_DAY_MASK) >> ALARM_DAY_S); 154 alrm->time.tm_hour = bcd2bin((alarm & TIME_HOUR_MASK) >> TIME_HOUR_S); 155 alrm->time.tm_min = bcd2bin((alarm & TIME_MIN_MASK) >> TIME_MIN_S); 156 alrm->time.tm_sec = bcd2bin((alarm & TIME_SEC_MASK)); 157 158 alrm->enabled = (alarm & ALARM_ENABLE_MASK) ? 1 : 0; 159 alrm->pending = (isr & VT8500_RTC_IS_ALARM) ? 1 : 0; 160 161 return rtc_valid_tm(&alrm->time); 162 } 163 164 static int vt8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 165 { 166 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); 167 168 writel((alrm->enabled ? ALARM_ENABLE_MASK : 0) 169 | (bin2bcd(alrm->time.tm_mday) << ALARM_DAY_S) 170 | (bin2bcd(alrm->time.tm_hour) << TIME_HOUR_S) 171 | (bin2bcd(alrm->time.tm_min) << TIME_MIN_S) 172 | (bin2bcd(alrm->time.tm_sec)), 173 vt8500_rtc->regbase + VT8500_RTC_AS); 174 175 return 0; 176 } 177 178 static int vt8500_alarm_irq_enable(struct device *dev, unsigned int enabled) 179 { 180 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); 181 unsigned long tmp = readl(vt8500_rtc->regbase + VT8500_RTC_AS); 182 183 if (enabled) 184 tmp |= ALARM_ENABLE_MASK; 185 else 186 tmp &= ~ALARM_ENABLE_MASK; 187 188 writel(tmp, vt8500_rtc->regbase + VT8500_RTC_AS); 189 return 0; 190 } 191 192 static const struct rtc_class_ops vt8500_rtc_ops = { 193 .read_time = vt8500_rtc_read_time, 194 .set_time = vt8500_rtc_set_time, 195 .read_alarm = vt8500_rtc_read_alarm, 196 .set_alarm = vt8500_rtc_set_alarm, 197 .alarm_irq_enable = vt8500_alarm_irq_enable, 198 }; 199 200 static int vt8500_rtc_probe(struct platform_device *pdev) 201 { 202 struct vt8500_rtc *vt8500_rtc; 203 struct resource *res; 204 int ret; 205 206 vt8500_rtc = devm_kzalloc(&pdev->dev, 207 sizeof(struct vt8500_rtc), GFP_KERNEL); 208 if (!vt8500_rtc) 209 return -ENOMEM; 210 211 spin_lock_init(&vt8500_rtc->lock); 212 platform_set_drvdata(pdev, vt8500_rtc); 213 214 vt8500_rtc->irq_alarm = platform_get_irq(pdev, 0); 215 if (vt8500_rtc->irq_alarm < 0) 216 return vt8500_rtc->irq_alarm; 217 218 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 219 vt8500_rtc->regbase = devm_ioremap_resource(&pdev->dev, res); 220 if (IS_ERR(vt8500_rtc->regbase)) 221 return PTR_ERR(vt8500_rtc->regbase); 222 223 /* Enable RTC and set it to 24-hour mode */ 224 writel(VT8500_RTC_CR_ENABLE, 225 vt8500_rtc->regbase + VT8500_RTC_CR); 226 227 vt8500_rtc->rtc = devm_rtc_device_register(&pdev->dev, "vt8500-rtc", 228 &vt8500_rtc_ops, THIS_MODULE); 229 if (IS_ERR(vt8500_rtc->rtc)) { 230 ret = PTR_ERR(vt8500_rtc->rtc); 231 dev_err(&pdev->dev, 232 "Failed to register RTC device -> %d\n", ret); 233 goto err_return; 234 } 235 236 ret = devm_request_irq(&pdev->dev, vt8500_rtc->irq_alarm, 237 vt8500_rtc_irq, 0, "rtc alarm", vt8500_rtc); 238 if (ret < 0) { 239 dev_err(&pdev->dev, "can't get irq %i, err %d\n", 240 vt8500_rtc->irq_alarm, ret); 241 goto err_return; 242 } 243 244 return 0; 245 246 err_return: 247 return ret; 248 } 249 250 static int vt8500_rtc_remove(struct platform_device *pdev) 251 { 252 struct vt8500_rtc *vt8500_rtc = platform_get_drvdata(pdev); 253 254 /* Disable alarm matching */ 255 writel(0, vt8500_rtc->regbase + VT8500_RTC_IS); 256 257 return 0; 258 } 259 260 static const struct of_device_id wmt_dt_ids[] = { 261 { .compatible = "via,vt8500-rtc", }, 262 {} 263 }; 264 MODULE_DEVICE_TABLE(of, wmt_dt_ids); 265 266 static struct platform_driver vt8500_rtc_driver = { 267 .probe = vt8500_rtc_probe, 268 .remove = vt8500_rtc_remove, 269 .driver = { 270 .name = "vt8500-rtc", 271 .of_match_table = wmt_dt_ids, 272 }, 273 }; 274 275 module_platform_driver(vt8500_rtc_driver); 276 277 MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>"); 278 MODULE_DESCRIPTION("VIA VT8500 SoC Realtime Clock Driver (RTC)"); 279 MODULE_LICENSE("GPL v2"); 280 MODULE_ALIAS("platform:vt8500-rtc"); 281