1 /* 2 * Driver for the RTC in Marvell SoCs. 3 * 4 * This file is licensed under the terms of the GNU General Public 5 * License version 2. This program is licensed "as is" without any 6 * warranty of any kind, whether express or implied. 7 */ 8 9 #include <linux/init.h> 10 #include <linux/kernel.h> 11 #include <linux/rtc.h> 12 #include <linux/bcd.h> 13 #include <linux/io.h> 14 #include <linux/platform_device.h> 15 #include <linux/of.h> 16 #include <linux/delay.h> 17 #include <linux/clk.h> 18 #include <linux/gfp.h> 19 #include <linux/module.h> 20 21 22 #define RTC_TIME_REG_OFFS 0 23 #define RTC_SECONDS_OFFS 0 24 #define RTC_MINUTES_OFFS 8 25 #define RTC_HOURS_OFFS 16 26 #define RTC_WDAY_OFFS 24 27 #define RTC_HOURS_12H_MODE (1 << 22) /* 12 hours mode */ 28 29 #define RTC_DATE_REG_OFFS 4 30 #define RTC_MDAY_OFFS 0 31 #define RTC_MONTH_OFFS 8 32 #define RTC_YEAR_OFFS 16 33 34 #define RTC_ALARM_TIME_REG_OFFS 8 35 #define RTC_ALARM_DATE_REG_OFFS 0xc 36 #define RTC_ALARM_VALID (1 << 7) 37 38 #define RTC_ALARM_INTERRUPT_MASK_REG_OFFS 0x10 39 #define RTC_ALARM_INTERRUPT_CASUE_REG_OFFS 0x14 40 41 struct rtc_plat_data { 42 struct rtc_device *rtc; 43 void __iomem *ioaddr; 44 int irq; 45 struct clk *clk; 46 }; 47 48 static int mv_rtc_set_time(struct device *dev, struct rtc_time *tm) 49 { 50 struct rtc_plat_data *pdata = dev_get_drvdata(dev); 51 void __iomem *ioaddr = pdata->ioaddr; 52 u32 rtc_reg; 53 54 rtc_reg = (bin2bcd(tm->tm_sec) << RTC_SECONDS_OFFS) | 55 (bin2bcd(tm->tm_min) << RTC_MINUTES_OFFS) | 56 (bin2bcd(tm->tm_hour) << RTC_HOURS_OFFS) | 57 (bin2bcd(tm->tm_wday) << RTC_WDAY_OFFS); 58 writel(rtc_reg, ioaddr + RTC_TIME_REG_OFFS); 59 60 rtc_reg = (bin2bcd(tm->tm_mday) << RTC_MDAY_OFFS) | 61 (bin2bcd(tm->tm_mon + 1) << RTC_MONTH_OFFS) | 62 (bin2bcd(tm->tm_year % 100) << RTC_YEAR_OFFS); 63 writel(rtc_reg, ioaddr + RTC_DATE_REG_OFFS); 64 65 return 0; 66 } 67 68 static int mv_rtc_read_time(struct device *dev, struct rtc_time *tm) 69 { 70 struct rtc_plat_data *pdata = dev_get_drvdata(dev); 71 void __iomem *ioaddr = pdata->ioaddr; 72 u32 rtc_time, rtc_date; 73 unsigned int year, month, day, hour, minute, second, wday; 74 75 rtc_time = readl(ioaddr + RTC_TIME_REG_OFFS); 76 rtc_date = readl(ioaddr + RTC_DATE_REG_OFFS); 77 78 second = rtc_time & 0x7f; 79 minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f; 80 hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hours mode */ 81 wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7; 82 83 day = rtc_date & 0x3f; 84 month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f; 85 year = (rtc_date >> RTC_YEAR_OFFS) & 0xff; 86 87 tm->tm_sec = bcd2bin(second); 88 tm->tm_min = bcd2bin(minute); 89 tm->tm_hour = bcd2bin(hour); 90 tm->tm_mday = bcd2bin(day); 91 tm->tm_wday = bcd2bin(wday); 92 tm->tm_mon = bcd2bin(month) - 1; 93 /* hw counts from year 2000, but tm_year is relative to 1900 */ 94 tm->tm_year = bcd2bin(year) + 100; 95 96 return rtc_valid_tm(tm); 97 } 98 99 static int mv_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) 100 { 101 struct rtc_plat_data *pdata = dev_get_drvdata(dev); 102 void __iomem *ioaddr = pdata->ioaddr; 103 u32 rtc_time, rtc_date; 104 unsigned int year, month, day, hour, minute, second, wday; 105 106 rtc_time = readl(ioaddr + RTC_ALARM_TIME_REG_OFFS); 107 rtc_date = readl(ioaddr + RTC_ALARM_DATE_REG_OFFS); 108 109 second = rtc_time & 0x7f; 110 minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f; 111 hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hours mode */ 112 wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7; 113 114 day = rtc_date & 0x3f; 115 month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f; 116 year = (rtc_date >> RTC_YEAR_OFFS) & 0xff; 117 118 alm->time.tm_sec = bcd2bin(second); 119 alm->time.tm_min = bcd2bin(minute); 120 alm->time.tm_hour = bcd2bin(hour); 121 alm->time.tm_mday = bcd2bin(day); 122 alm->time.tm_wday = bcd2bin(wday); 123 alm->time.tm_mon = bcd2bin(month) - 1; 124 /* hw counts from year 2000, but tm_year is relative to 1900 */ 125 alm->time.tm_year = bcd2bin(year) + 100; 126 127 if (rtc_valid_tm(&alm->time) < 0) { 128 dev_err(dev, "retrieved alarm date/time is not valid.\n"); 129 rtc_time_to_tm(0, &alm->time); 130 } 131 132 alm->enabled = !!readl(ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS); 133 return 0; 134 } 135 136 static int mv_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) 137 { 138 struct rtc_plat_data *pdata = dev_get_drvdata(dev); 139 void __iomem *ioaddr = pdata->ioaddr; 140 u32 rtc_reg = 0; 141 142 if (alm->time.tm_sec >= 0) 143 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_sec)) 144 << RTC_SECONDS_OFFS; 145 if (alm->time.tm_min >= 0) 146 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_min)) 147 << RTC_MINUTES_OFFS; 148 if (alm->time.tm_hour >= 0) 149 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_hour)) 150 << RTC_HOURS_OFFS; 151 152 writel(rtc_reg, ioaddr + RTC_ALARM_TIME_REG_OFFS); 153 154 if (alm->time.tm_mday >= 0) 155 rtc_reg = (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mday)) 156 << RTC_MDAY_OFFS; 157 else 158 rtc_reg = 0; 159 160 if (alm->time.tm_mon >= 0) 161 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mon + 1)) 162 << RTC_MONTH_OFFS; 163 164 if (alm->time.tm_year >= 0) 165 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_year % 100)) 166 << RTC_YEAR_OFFS; 167 168 writel(rtc_reg, ioaddr + RTC_ALARM_DATE_REG_OFFS); 169 writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS); 170 writel(alm->enabled ? 1 : 0, 171 ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS); 172 173 return 0; 174 } 175 176 static int mv_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) 177 { 178 struct platform_device *pdev = to_platform_device(dev); 179 struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 180 void __iomem *ioaddr = pdata->ioaddr; 181 182 if (pdata->irq < 0) 183 return -EINVAL; /* fall back into rtc-dev's emulation */ 184 185 if (enabled) 186 writel(1, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS); 187 else 188 writel(0, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS); 189 return 0; 190 } 191 192 static irqreturn_t mv_rtc_interrupt(int irq, void *data) 193 { 194 struct rtc_plat_data *pdata = data; 195 void __iomem *ioaddr = pdata->ioaddr; 196 197 /* alarm irq? */ 198 if (!readl(ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS)) 199 return IRQ_NONE; 200 201 /* clear interrupt */ 202 writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS); 203 rtc_update_irq(pdata->rtc, 1, RTC_IRQF | RTC_AF); 204 return IRQ_HANDLED; 205 } 206 207 static const struct rtc_class_ops mv_rtc_ops = { 208 .read_time = mv_rtc_read_time, 209 .set_time = mv_rtc_set_time, 210 }; 211 212 static const struct rtc_class_ops mv_rtc_alarm_ops = { 213 .read_time = mv_rtc_read_time, 214 .set_time = mv_rtc_set_time, 215 .read_alarm = mv_rtc_read_alarm, 216 .set_alarm = mv_rtc_set_alarm, 217 .alarm_irq_enable = mv_rtc_alarm_irq_enable, 218 }; 219 220 static int __init mv_rtc_probe(struct platform_device *pdev) 221 { 222 struct resource *res; 223 struct rtc_plat_data *pdata; 224 u32 rtc_time; 225 u32 rtc_date; 226 int ret = 0; 227 228 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); 229 if (!pdata) 230 return -ENOMEM; 231 232 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 233 pdata->ioaddr = devm_ioremap_resource(&pdev->dev, res); 234 if (IS_ERR(pdata->ioaddr)) 235 return PTR_ERR(pdata->ioaddr); 236 237 pdata->clk = devm_clk_get(&pdev->dev, NULL); 238 /* Not all SoCs require a clock.*/ 239 if (!IS_ERR(pdata->clk)) 240 clk_prepare_enable(pdata->clk); 241 242 /* make sure the 24 hours mode is enabled */ 243 rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS); 244 if (rtc_time & RTC_HOURS_12H_MODE) { 245 dev_err(&pdev->dev, "24 Hours mode not supported.\n"); 246 ret = -EINVAL; 247 goto out; 248 } 249 250 /* make sure it is actually functional */ 251 if (rtc_time == 0x01000000) { 252 ssleep(1); 253 rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS); 254 if (rtc_time == 0x01000000) { 255 dev_err(&pdev->dev, "internal RTC not ticking\n"); 256 ret = -ENODEV; 257 goto out; 258 } 259 } 260 261 /* 262 * A date after January 19th, 2038 does not fit on 32 bits and 263 * will confuse the kernel and userspace. Reset to a sane date 264 * (January 1st, 2013) if we're after 2038. 265 */ 266 rtc_date = readl(pdata->ioaddr + RTC_DATE_REG_OFFS); 267 if (bcd2bin((rtc_date >> RTC_YEAR_OFFS) & 0xff) >= 38) { 268 dev_info(&pdev->dev, "invalid RTC date, resetting to January 1st, 2013\n"); 269 writel(0x130101, pdata->ioaddr + RTC_DATE_REG_OFFS); 270 } 271 272 pdata->irq = platform_get_irq(pdev, 0); 273 274 platform_set_drvdata(pdev, pdata); 275 276 if (pdata->irq >= 0) { 277 device_init_wakeup(&pdev->dev, 1); 278 pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, 279 &mv_rtc_alarm_ops, 280 THIS_MODULE); 281 } else { 282 pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, 283 &mv_rtc_ops, THIS_MODULE); 284 } 285 if (IS_ERR(pdata->rtc)) { 286 ret = PTR_ERR(pdata->rtc); 287 goto out; 288 } 289 290 if (pdata->irq >= 0) { 291 writel(0, pdata->ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS); 292 if (devm_request_irq(&pdev->dev, pdata->irq, mv_rtc_interrupt, 293 IRQF_SHARED, 294 pdev->name, pdata) < 0) { 295 dev_warn(&pdev->dev, "interrupt not available.\n"); 296 pdata->irq = -1; 297 } 298 } 299 300 return 0; 301 out: 302 if (!IS_ERR(pdata->clk)) 303 clk_disable_unprepare(pdata->clk); 304 305 return ret; 306 } 307 308 static int __exit mv_rtc_remove(struct platform_device *pdev) 309 { 310 struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 311 312 if (pdata->irq >= 0) 313 device_init_wakeup(&pdev->dev, 0); 314 315 if (!IS_ERR(pdata->clk)) 316 clk_disable_unprepare(pdata->clk); 317 318 return 0; 319 } 320 321 #ifdef CONFIG_OF 322 static const struct of_device_id rtc_mv_of_match_table[] = { 323 { .compatible = "marvell,orion-rtc", }, 324 {} 325 }; 326 #endif 327 328 static struct platform_driver mv_rtc_driver = { 329 .remove = __exit_p(mv_rtc_remove), 330 .driver = { 331 .name = "rtc-mv", 332 .of_match_table = of_match_ptr(rtc_mv_of_match_table), 333 }, 334 }; 335 336 module_platform_driver_probe(mv_rtc_driver, mv_rtc_probe); 337 338 MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>"); 339 MODULE_DESCRIPTION("Marvell RTC driver"); 340 MODULE_LICENSE("GPL"); 341 MODULE_ALIAS("platform:rtc-mv"); 342