1 /* 2 * drivers/rtc/rtc-vt8500.c 3 * 4 * Copyright (C) 2010 Alexey Charkov <alchark@gmail.com> 5 * 6 * Based on rtc-pxa.c 7 * 8 * This software is licensed under the terms of the GNU General Public 9 * License version 2, as published by the Free Software Foundation, and 10 * may be copied, distributed, and modified under those terms. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 */ 17 18 #include <linux/module.h> 19 #include <linux/rtc.h> 20 #include <linux/init.h> 21 #include <linux/interrupt.h> 22 #include <linux/io.h> 23 #include <linux/bcd.h> 24 #include <linux/platform_device.h> 25 #include <linux/slab.h> 26 #include <linux/of.h> 27 28 /* 29 * Register definitions 30 */ 31 #define VT8500_RTC_TS 0x00 /* Time set */ 32 #define VT8500_RTC_DS 0x04 /* Date set */ 33 #define VT8500_RTC_AS 0x08 /* Alarm set */ 34 #define VT8500_RTC_CR 0x0c /* Control */ 35 #define VT8500_RTC_TR 0x10 /* Time read */ 36 #define VT8500_RTC_DR 0x14 /* Date read */ 37 #define VT8500_RTC_WS 0x18 /* Write status */ 38 #define VT8500_RTC_CL 0x20 /* Calibration */ 39 #define VT8500_RTC_IS 0x24 /* Interrupt status */ 40 #define VT8500_RTC_ST 0x28 /* Status */ 41 42 #define INVALID_TIME_BIT (1 << 31) 43 44 #define DATE_CENTURY_S 19 45 #define DATE_YEAR_S 11 46 #define DATE_YEAR_MASK (0xff << DATE_YEAR_S) 47 #define DATE_MONTH_S 6 48 #define DATE_MONTH_MASK (0x1f << DATE_MONTH_S) 49 #define DATE_DAY_MASK 0x3f 50 51 #define TIME_DOW_S 20 52 #define TIME_DOW_MASK (0x07 << TIME_DOW_S) 53 #define TIME_HOUR_S 14 54 #define TIME_HOUR_MASK (0x3f << TIME_HOUR_S) 55 #define TIME_MIN_S 7 56 #define TIME_MIN_MASK (0x7f << TIME_MIN_S) 57 #define TIME_SEC_MASK 0x7f 58 59 #define ALARM_DAY_S 20 60 #define ALARM_DAY_MASK (0x3f << ALARM_DAY_S) 61 62 #define ALARM_DAY_BIT (1 << 29) 63 #define ALARM_HOUR_BIT (1 << 28) 64 #define ALARM_MIN_BIT (1 << 27) 65 #define ALARM_SEC_BIT (1 << 26) 66 67 #define ALARM_ENABLE_MASK (ALARM_DAY_BIT \ 68 | ALARM_HOUR_BIT \ 69 | ALARM_MIN_BIT \ 70 | ALARM_SEC_BIT) 71 72 #define VT8500_RTC_CR_ENABLE (1 << 0) /* Enable RTC */ 73 #define VT8500_RTC_CR_12H (1 << 1) /* 12h time format */ 74 #define VT8500_RTC_CR_SM_ENABLE (1 << 2) /* Enable periodic irqs */ 75 #define VT8500_RTC_CR_SM_SEC (1 << 3) /* 0: 1Hz/60, 1: 1Hz */ 76 #define VT8500_RTC_CR_CALIB (1 << 4) /* Enable calibration */ 77 78 #define VT8500_RTC_IS_ALARM (1 << 0) /* Alarm interrupt status */ 79 80 struct vt8500_rtc { 81 void __iomem *regbase; 82 int irq_alarm; 83 struct rtc_device *rtc; 84 spinlock_t lock; /* Protects this structure */ 85 }; 86 87 static irqreturn_t vt8500_rtc_irq(int irq, void *dev_id) 88 { 89 struct vt8500_rtc *vt8500_rtc = dev_id; 90 u32 isr; 91 unsigned long events = 0; 92 93 spin_lock(&vt8500_rtc->lock); 94 95 /* clear interrupt sources */ 96 isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS); 97 writel(isr, vt8500_rtc->regbase + VT8500_RTC_IS); 98 99 spin_unlock(&vt8500_rtc->lock); 100 101 if (isr & VT8500_RTC_IS_ALARM) 102 events |= RTC_AF | RTC_IRQF; 103 104 rtc_update_irq(vt8500_rtc->rtc, 1, events); 105 106 return IRQ_HANDLED; 107 } 108 109 static int vt8500_rtc_read_time(struct device *dev, struct rtc_time *tm) 110 { 111 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); 112 u32 date, time; 113 114 date = readl(vt8500_rtc->regbase + VT8500_RTC_DR); 115 time = readl(vt8500_rtc->regbase + VT8500_RTC_TR); 116 117 tm->tm_sec = bcd2bin(time & TIME_SEC_MASK); 118 tm->tm_min = bcd2bin((time & TIME_MIN_MASK) >> TIME_MIN_S); 119 tm->tm_hour = bcd2bin((time & TIME_HOUR_MASK) >> TIME_HOUR_S); 120 tm->tm_mday = bcd2bin(date & DATE_DAY_MASK); 121 tm->tm_mon = bcd2bin((date & DATE_MONTH_MASK) >> DATE_MONTH_S) - 1; 122 tm->tm_year = bcd2bin((date & DATE_YEAR_MASK) >> DATE_YEAR_S) 123 + ((date >> DATE_CENTURY_S) & 1 ? 200 : 100); 124 tm->tm_wday = (time & TIME_DOW_MASK) >> TIME_DOW_S; 125 126 return 0; 127 } 128 129 static int vt8500_rtc_set_time(struct device *dev, struct rtc_time *tm) 130 { 131 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); 132 133 if (tm->tm_year < 100) { 134 dev_warn(dev, "Only years 2000-2199 are supported by the " 135 "hardware!\n"); 136 return -EINVAL; 137 } 138 139 writel((bin2bcd(tm->tm_year % 100) << DATE_YEAR_S) 140 | (bin2bcd(tm->tm_mon + 1) << DATE_MONTH_S) 141 | (bin2bcd(tm->tm_mday)) 142 | ((tm->tm_year >= 200) << DATE_CENTURY_S), 143 vt8500_rtc->regbase + VT8500_RTC_DS); 144 writel((bin2bcd(tm->tm_wday) << TIME_DOW_S) 145 | (bin2bcd(tm->tm_hour) << TIME_HOUR_S) 146 | (bin2bcd(tm->tm_min) << TIME_MIN_S) 147 | (bin2bcd(tm->tm_sec)), 148 vt8500_rtc->regbase + VT8500_RTC_TS); 149 150 return 0; 151 } 152 153 static int vt8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 154 { 155 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); 156 u32 isr, alarm; 157 158 alarm = readl(vt8500_rtc->regbase + VT8500_RTC_AS); 159 isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS); 160 161 alrm->time.tm_mday = bcd2bin((alarm & ALARM_DAY_MASK) >> ALARM_DAY_S); 162 alrm->time.tm_hour = bcd2bin((alarm & TIME_HOUR_MASK) >> TIME_HOUR_S); 163 alrm->time.tm_min = bcd2bin((alarm & TIME_MIN_MASK) >> TIME_MIN_S); 164 alrm->time.tm_sec = bcd2bin((alarm & TIME_SEC_MASK)); 165 166 alrm->enabled = (alarm & ALARM_ENABLE_MASK) ? 1 : 0; 167 alrm->pending = (isr & VT8500_RTC_IS_ALARM) ? 1 : 0; 168 169 return rtc_valid_tm(&alrm->time); 170 } 171 172 static int vt8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 173 { 174 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); 175 176 writel((alrm->enabled ? ALARM_ENABLE_MASK : 0) 177 | (bin2bcd(alrm->time.tm_mday) << ALARM_DAY_S) 178 | (bin2bcd(alrm->time.tm_hour) << TIME_HOUR_S) 179 | (bin2bcd(alrm->time.tm_min) << TIME_MIN_S) 180 | (bin2bcd(alrm->time.tm_sec)), 181 vt8500_rtc->regbase + VT8500_RTC_AS); 182 183 return 0; 184 } 185 186 static int vt8500_alarm_irq_enable(struct device *dev, unsigned int enabled) 187 { 188 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); 189 unsigned long tmp = readl(vt8500_rtc->regbase + VT8500_RTC_AS); 190 191 if (enabled) 192 tmp |= ALARM_ENABLE_MASK; 193 else 194 tmp &= ~ALARM_ENABLE_MASK; 195 196 writel(tmp, vt8500_rtc->regbase + VT8500_RTC_AS); 197 return 0; 198 } 199 200 static const struct rtc_class_ops vt8500_rtc_ops = { 201 .read_time = vt8500_rtc_read_time, 202 .set_time = vt8500_rtc_set_time, 203 .read_alarm = vt8500_rtc_read_alarm, 204 .set_alarm = vt8500_rtc_set_alarm, 205 .alarm_irq_enable = vt8500_alarm_irq_enable, 206 }; 207 208 static int vt8500_rtc_probe(struct platform_device *pdev) 209 { 210 struct vt8500_rtc *vt8500_rtc; 211 struct resource *res; 212 int ret; 213 214 vt8500_rtc = devm_kzalloc(&pdev->dev, 215 sizeof(struct vt8500_rtc), GFP_KERNEL); 216 if (!vt8500_rtc) 217 return -ENOMEM; 218 219 spin_lock_init(&vt8500_rtc->lock); 220 platform_set_drvdata(pdev, vt8500_rtc); 221 222 vt8500_rtc->irq_alarm = platform_get_irq(pdev, 0); 223 if (vt8500_rtc->irq_alarm < 0) { 224 dev_err(&pdev->dev, "No alarm IRQ resource defined\n"); 225 return vt8500_rtc->irq_alarm; 226 } 227 228 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 229 vt8500_rtc->regbase = devm_ioremap_resource(&pdev->dev, res); 230 if (IS_ERR(vt8500_rtc->regbase)) 231 return PTR_ERR(vt8500_rtc->regbase); 232 233 /* Enable RTC and set it to 24-hour mode */ 234 writel(VT8500_RTC_CR_ENABLE, 235 vt8500_rtc->regbase + VT8500_RTC_CR); 236 237 vt8500_rtc->rtc = devm_rtc_device_register(&pdev->dev, "vt8500-rtc", 238 &vt8500_rtc_ops, THIS_MODULE); 239 if (IS_ERR(vt8500_rtc->rtc)) { 240 ret = PTR_ERR(vt8500_rtc->rtc); 241 dev_err(&pdev->dev, 242 "Failed to register RTC device -> %d\n", ret); 243 goto err_return; 244 } 245 246 ret = devm_request_irq(&pdev->dev, vt8500_rtc->irq_alarm, 247 vt8500_rtc_irq, 0, "rtc alarm", vt8500_rtc); 248 if (ret < 0) { 249 dev_err(&pdev->dev, "can't get irq %i, err %d\n", 250 vt8500_rtc->irq_alarm, ret); 251 goto err_return; 252 } 253 254 return 0; 255 256 err_return: 257 return ret; 258 } 259 260 static int vt8500_rtc_remove(struct platform_device *pdev) 261 { 262 struct vt8500_rtc *vt8500_rtc = platform_get_drvdata(pdev); 263 264 /* Disable alarm matching */ 265 writel(0, vt8500_rtc->regbase + VT8500_RTC_IS); 266 267 return 0; 268 } 269 270 static const struct of_device_id wmt_dt_ids[] = { 271 { .compatible = "via,vt8500-rtc", }, 272 {} 273 }; 274 MODULE_DEVICE_TABLE(of, wmt_dt_ids); 275 276 static struct platform_driver vt8500_rtc_driver = { 277 .probe = vt8500_rtc_probe, 278 .remove = vt8500_rtc_remove, 279 .driver = { 280 .name = "vt8500-rtc", 281 .of_match_table = wmt_dt_ids, 282 }, 283 }; 284 285 module_platform_driver(vt8500_rtc_driver); 286 287 MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>"); 288 MODULE_DESCRIPTION("VIA VT8500 SoC Realtime Clock Driver (RTC)"); 289 MODULE_LICENSE("GPL v2"); 290 MODULE_ALIAS("platform:vt8500-rtc"); 291