1/* 2 * Copyright (c) 2008-2009 Nuvoton technology corporation. 3 * 4 * Wan ZongShun <mcuos.com@gmail.com> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation;version 2 of the License. 9 * 10 */ 11 12#include <linux/module.h> 13#include <linux/init.h> 14#include <linux/platform_device.h> 15#include <linux/slab.h> 16#include <linux/rtc.h> 17#include <linux/delay.h> 18#include <linux/io.h> 19#include <linux/bcd.h> 20 21/* RTC Control Registers */ 22#define REG_RTC_INIR 0x00 23#define REG_RTC_AER 0x04 24#define REG_RTC_FCR 0x08 25#define REG_RTC_TLR 0x0C 26#define REG_RTC_CLR 0x10 27#define REG_RTC_TSSR 0x14 28#define REG_RTC_DWR 0x18 29#define REG_RTC_TAR 0x1C 30#define REG_RTC_CAR 0x20 31#define REG_RTC_LIR 0x24 32#define REG_RTC_RIER 0x28 33#define REG_RTC_RIIR 0x2C 34#define REG_RTC_TTR 0x30 35 36#define RTCSET 0x01 37#define AERRWENB 0x10000 38#define INIRRESET 0xa5eb1357 39#define AERPOWERON 0xA965 40#define AERPOWEROFF 0x0000 41#define LEAPYEAR 0x0001 42#define TICKENB 0x80 43#define TICKINTENB 0x0002 44#define ALARMINTENB 0x0001 45#define MODE24 0x0001 46 47struct nuc900_rtc { 48 int irq_num; 49 void __iomem *rtc_reg; 50 struct rtc_device *rtcdev; 51}; 52 53struct nuc900_bcd_time { 54 int bcd_sec; 55 int bcd_min; 56 int bcd_hour; 57 int bcd_mday; 58 int bcd_mon; 59 int bcd_year; 60}; 61 62static irqreturn_t nuc900_rtc_interrupt(int irq, void *_rtc) 63{ 64 struct nuc900_rtc *rtc = _rtc; 65 unsigned long events = 0, rtc_irq; 66 67 rtc_irq = __raw_readl(rtc->rtc_reg + REG_RTC_RIIR); 68 69 if (rtc_irq & ALARMINTENB) { 70 rtc_irq &= ~ALARMINTENB; 71 __raw_writel(rtc_irq, rtc->rtc_reg + REG_RTC_RIIR); 72 events |= RTC_AF | RTC_IRQF; 73 } 74 75 if (rtc_irq & TICKINTENB) { 76 rtc_irq &= ~TICKINTENB; 77 __raw_writel(rtc_irq, rtc->rtc_reg + REG_RTC_RIIR); 78 events |= RTC_UF | RTC_IRQF; 79 } 80 81 rtc_update_irq(rtc->rtcdev, 1, events); 82 83 return IRQ_HANDLED; 84} 85 86static int *check_rtc_access_enable(struct nuc900_rtc *nuc900_rtc) 87{ 88 unsigned int timeout = 0x1000; 89 __raw_writel(INIRRESET, nuc900_rtc->rtc_reg + REG_RTC_INIR); 90 91 mdelay(10); 92 93 __raw_writel(AERPOWERON, nuc900_rtc->rtc_reg + REG_RTC_AER); 94 95 while (!(__raw_readl(nuc900_rtc->rtc_reg + REG_RTC_AER) & AERRWENB) 96 && timeout--) 97 mdelay(1); 98 99 if (!timeout) 100 return ERR_PTR(-EPERM); 101 102 return NULL; 103} 104 105static int nuc900_rtc_bcd2bin(unsigned int timereg, 106 unsigned int calreg, struct rtc_time *tm) 107{ 108 tm->tm_mday = bcd2bin(calreg >> 0); 109 tm->tm_mon = bcd2bin(calreg >> 8); 110 tm->tm_year = bcd2bin(calreg >> 16) + 100; 111 112 tm->tm_sec = bcd2bin(timereg >> 0); 113 tm->tm_min = bcd2bin(timereg >> 8); 114 tm->tm_hour = bcd2bin(timereg >> 16); 115 116 return rtc_valid_tm(tm); 117} 118 119static void nuc900_rtc_bin2bcd(struct device *dev, struct rtc_time *settm, 120 struct nuc900_bcd_time *gettm) 121{ 122 gettm->bcd_mday = bin2bcd(settm->tm_mday) << 0; 123 gettm->bcd_mon = bin2bcd(settm->tm_mon) << 8; 124 125 if (settm->tm_year < 100) { 126 dev_warn(dev, "The year will be between 1970-1999, right?\n"); 127 gettm->bcd_year = bin2bcd(settm->tm_year) << 16; 128 } else { 129 gettm->bcd_year = bin2bcd(settm->tm_year - 100) << 16; 130 } 131 132 gettm->bcd_sec = bin2bcd(settm->tm_sec) << 0; 133 gettm->bcd_min = bin2bcd(settm->tm_min) << 8; 134 gettm->bcd_hour = bin2bcd(settm->tm_hour) << 16; 135} 136 137static int nuc900_alarm_irq_enable(struct device *dev, unsigned int enabled) 138{ 139 struct nuc900_rtc *rtc = dev_get_drvdata(dev); 140 141 if (enabled) 142 __raw_writel(__raw_readl(rtc->rtc_reg + REG_RTC_RIER)| 143 (ALARMINTENB), rtc->rtc_reg + REG_RTC_RIER); 144 else 145 __raw_writel(__raw_readl(rtc->rtc_reg + REG_RTC_RIER)& 146 (~ALARMINTENB), rtc->rtc_reg + REG_RTC_RIER); 147 148 return 0; 149} 150 151static int nuc900_rtc_read_time(struct device *dev, struct rtc_time *tm) 152{ 153 struct nuc900_rtc *rtc = dev_get_drvdata(dev); 154 unsigned int timeval, clrval; 155 156 timeval = __raw_readl(rtc->rtc_reg + REG_RTC_TLR); 157 clrval = __raw_readl(rtc->rtc_reg + REG_RTC_CLR); 158 159 return nuc900_rtc_bcd2bin(timeval, clrval, tm); 160} 161 162static int nuc900_rtc_set_time(struct device *dev, struct rtc_time *tm) 163{ 164 struct nuc900_rtc *rtc = dev_get_drvdata(dev); 165 struct nuc900_bcd_time gettm; 166 unsigned long val; 167 int *err; 168 169 nuc900_rtc_bin2bcd(dev, tm, &gettm); 170 171 err = check_rtc_access_enable(rtc); 172 if (IS_ERR(err)) 173 return PTR_ERR(err); 174 175 val = gettm.bcd_mday | gettm.bcd_mon | gettm.bcd_year; 176 __raw_writel(val, rtc->rtc_reg + REG_RTC_CLR); 177 178 val = gettm.bcd_sec | gettm.bcd_min | gettm.bcd_hour; 179 __raw_writel(val, rtc->rtc_reg + REG_RTC_TLR); 180 181 return 0; 182} 183 184static int nuc900_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 185{ 186 struct nuc900_rtc *rtc = dev_get_drvdata(dev); 187 unsigned int timeval, carval; 188 189 timeval = __raw_readl(rtc->rtc_reg + REG_RTC_TAR); 190 carval = __raw_readl(rtc->rtc_reg + REG_RTC_CAR); 191 192 return nuc900_rtc_bcd2bin(timeval, carval, &alrm->time); 193} 194 195static int nuc900_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 196{ 197 struct nuc900_rtc *rtc = dev_get_drvdata(dev); 198 struct nuc900_bcd_time tm; 199 unsigned long val; 200 int *err; 201 202 nuc900_rtc_bin2bcd(dev, &alrm->time, &tm); 203 204 err = check_rtc_access_enable(rtc); 205 if (IS_ERR(err)) 206 return PTR_ERR(err); 207 208 val = tm.bcd_mday | tm.bcd_mon | tm.bcd_year; 209 __raw_writel(val, rtc->rtc_reg + REG_RTC_CAR); 210 211 val = tm.bcd_sec | tm.bcd_min | tm.bcd_hour; 212 __raw_writel(val, rtc->rtc_reg + REG_RTC_TAR); 213 214 return 0; 215} 216 217static struct rtc_class_ops nuc900_rtc_ops = { 218 .read_time = nuc900_rtc_read_time, 219 .set_time = nuc900_rtc_set_time, 220 .read_alarm = nuc900_rtc_read_alarm, 221 .set_alarm = nuc900_rtc_set_alarm, 222 .alarm_irq_enable = nuc900_alarm_irq_enable, 223}; 224 225static int __init nuc900_rtc_probe(struct platform_device *pdev) 226{ 227 struct resource *res; 228 struct nuc900_rtc *nuc900_rtc; 229 230 nuc900_rtc = devm_kzalloc(&pdev->dev, sizeof(struct nuc900_rtc), 231 GFP_KERNEL); 232 if (!nuc900_rtc) 233 return -ENOMEM; 234 235 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 236 nuc900_rtc->rtc_reg = devm_ioremap_resource(&pdev->dev, res); 237 if (IS_ERR(nuc900_rtc->rtc_reg)) 238 return PTR_ERR(nuc900_rtc->rtc_reg); 239 240 platform_set_drvdata(pdev, nuc900_rtc); 241 242 nuc900_rtc->rtcdev = devm_rtc_device_register(&pdev->dev, pdev->name, 243 &nuc900_rtc_ops, THIS_MODULE); 244 if (IS_ERR(nuc900_rtc->rtcdev)) { 245 dev_err(&pdev->dev, "rtc device register failed\n"); 246 return PTR_ERR(nuc900_rtc->rtcdev); 247 } 248 249 __raw_writel(__raw_readl(nuc900_rtc->rtc_reg + REG_RTC_TSSR) | MODE24, 250 nuc900_rtc->rtc_reg + REG_RTC_TSSR); 251 252 nuc900_rtc->irq_num = platform_get_irq(pdev, 0); 253 if (devm_request_irq(&pdev->dev, nuc900_rtc->irq_num, 254 nuc900_rtc_interrupt, 0, "nuc900rtc", nuc900_rtc)) { 255 dev_err(&pdev->dev, "NUC900 RTC request irq failed\n"); 256 return -EBUSY; 257 } 258 259 return 0; 260} 261 262static struct platform_driver nuc900_rtc_driver = { 263 .driver = { 264 .name = "nuc900-rtc", 265 }, 266}; 267 268module_platform_driver_probe(nuc900_rtc_driver, nuc900_rtc_probe); 269 270MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>"); 271MODULE_DESCRIPTION("nuc910/nuc920 RTC driver"); 272MODULE_LICENSE("GPL"); 273MODULE_ALIAS("platform:nuc900-rtc"); 274