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/bitops.h> 14 #include <linux/io.h> 15 #include <linux/platform_device.h> 16 #include <linux/of.h> 17 #include <linux/delay.h> 18 #include <linux/clk.h> 19 #include <linux/gfp.h> 20 #include <linux/module.h> 21 22 23 #define RTC_TIME_REG_OFFS 0 24 #define RTC_SECONDS_OFFS 0 25 #define RTC_MINUTES_OFFS 8 26 #define RTC_HOURS_OFFS 16 27 #define RTC_WDAY_OFFS 24 28 #define RTC_HOURS_12H_MODE BIT(22) /* 12 hour mode */ 29 30 #define RTC_DATE_REG_OFFS 4 31 #define RTC_MDAY_OFFS 0 32 #define RTC_MONTH_OFFS 8 33 #define RTC_YEAR_OFFS 16 34 35 #define RTC_ALARM_TIME_REG_OFFS 8 36 #define RTC_ALARM_DATE_REG_OFFS 0xc 37 #define RTC_ALARM_VALID BIT(7) 38 39 #define RTC_ALARM_INTERRUPT_MASK_REG_OFFS 0x10 40 #define RTC_ALARM_INTERRUPT_CASUE_REG_OFFS 0x14 41 42 struct rtc_plat_data { 43 struct rtc_device *rtc; 44 void __iomem *ioaddr; 45 int irq; 46 struct clk *clk; 47 }; 48 49 static int mv_rtc_set_time(struct device *dev, struct rtc_time *tm) 50 { 51 struct rtc_plat_data *pdata = dev_get_drvdata(dev); 52 void __iomem *ioaddr = pdata->ioaddr; 53 u32 rtc_reg; 54 55 rtc_reg = (bin2bcd(tm->tm_sec) << RTC_SECONDS_OFFS) | 56 (bin2bcd(tm->tm_min) << RTC_MINUTES_OFFS) | 57 (bin2bcd(tm->tm_hour) << RTC_HOURS_OFFS) | 58 (bin2bcd(tm->tm_wday) << RTC_WDAY_OFFS); 59 writel(rtc_reg, ioaddr + RTC_TIME_REG_OFFS); 60 61 rtc_reg = (bin2bcd(tm->tm_mday) << RTC_MDAY_OFFS) | 62 (bin2bcd(tm->tm_mon + 1) << RTC_MONTH_OFFS) | 63 (bin2bcd(tm->tm_year % 100) << RTC_YEAR_OFFS); 64 writel(rtc_reg, ioaddr + RTC_DATE_REG_OFFS); 65 66 return 0; 67 } 68 69 static int mv_rtc_read_time(struct device *dev, struct rtc_time *tm) 70 { 71 struct rtc_plat_data *pdata = dev_get_drvdata(dev); 72 void __iomem *ioaddr = pdata->ioaddr; 73 u32 rtc_time, rtc_date; 74 unsigned int year, month, day, hour, minute, second, wday; 75 76 rtc_time = readl(ioaddr + RTC_TIME_REG_OFFS); 77 rtc_date = readl(ioaddr + RTC_DATE_REG_OFFS); 78 79 second = rtc_time & 0x7f; 80 minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f; 81 hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hour mode */ 82 wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7; 83 84 day = rtc_date & 0x3f; 85 month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f; 86 year = (rtc_date >> RTC_YEAR_OFFS) & 0xff; 87 88 tm->tm_sec = bcd2bin(second); 89 tm->tm_min = bcd2bin(minute); 90 tm->tm_hour = bcd2bin(hour); 91 tm->tm_mday = bcd2bin(day); 92 tm->tm_wday = bcd2bin(wday); 93 tm->tm_mon = bcd2bin(month) - 1; 94 /* hw counts from year 2000, but tm_year is relative to 1900 */ 95 tm->tm_year = bcd2bin(year) + 100; 96 97 return rtc_valid_tm(tm); 98 } 99 100 static int mv_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) 101 { 102 struct rtc_plat_data *pdata = dev_get_drvdata(dev); 103 void __iomem *ioaddr = pdata->ioaddr; 104 u32 rtc_time, rtc_date; 105 unsigned int year, month, day, hour, minute, second, wday; 106 107 rtc_time = readl(ioaddr + RTC_ALARM_TIME_REG_OFFS); 108 rtc_date = readl(ioaddr + RTC_ALARM_DATE_REG_OFFS); 109 110 second = rtc_time & 0x7f; 111 minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f; 112 hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hour mode */ 113 wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7; 114 115 day = rtc_date & 0x3f; 116 month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f; 117 year = (rtc_date >> RTC_YEAR_OFFS) & 0xff; 118 119 alm->time.tm_sec = bcd2bin(second); 120 alm->time.tm_min = bcd2bin(minute); 121 alm->time.tm_hour = bcd2bin(hour); 122 alm->time.tm_mday = bcd2bin(day); 123 alm->time.tm_wday = bcd2bin(wday); 124 alm->time.tm_mon = bcd2bin(month) - 1; 125 /* hw counts from year 2000, but tm_year is relative to 1900 */ 126 alm->time.tm_year = bcd2bin(year) + 100; 127 128 if (rtc_valid_tm(&alm->time) < 0) { 129 dev_err(dev, "retrieved alarm date/time is not valid.\n"); 130 rtc_time_to_tm(0, &alm->time); 131 } 132 133 alm->enabled = !!readl(ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS); 134 return 0; 135 } 136 137 static int mv_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) 138 { 139 struct rtc_plat_data *pdata = dev_get_drvdata(dev); 140 void __iomem *ioaddr = pdata->ioaddr; 141 u32 rtc_reg = 0; 142 143 if (alm->time.tm_sec >= 0) 144 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_sec)) 145 << RTC_SECONDS_OFFS; 146 if (alm->time.tm_min >= 0) 147 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_min)) 148 << RTC_MINUTES_OFFS; 149 if (alm->time.tm_hour >= 0) 150 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_hour)) 151 << RTC_HOURS_OFFS; 152 153 writel(rtc_reg, ioaddr + RTC_ALARM_TIME_REG_OFFS); 154 155 if (alm->time.tm_mday >= 0) 156 rtc_reg = (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mday)) 157 << RTC_MDAY_OFFS; 158 else 159 rtc_reg = 0; 160 161 if (alm->time.tm_mon >= 0) 162 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mon + 1)) 163 << RTC_MONTH_OFFS; 164 165 if (alm->time.tm_year >= 0) 166 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_year % 100)) 167 << RTC_YEAR_OFFS; 168 169 writel(rtc_reg, ioaddr + RTC_ALARM_DATE_REG_OFFS); 170 writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS); 171 writel(alm->enabled ? 1 : 0, 172 ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS); 173 174 return 0; 175 } 176 177 static int mv_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) 178 { 179 struct platform_device *pdev = to_platform_device(dev); 180 struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 181 void __iomem *ioaddr = pdata->ioaddr; 182 183 if (pdata->irq < 0) 184 return -EINVAL; /* fall back into rtc-dev's emulation */ 185 186 if (enabled) 187 writel(1, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS); 188 else 189 writel(0, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS); 190 return 0; 191 } 192 193 static irqreturn_t mv_rtc_interrupt(int irq, void *data) 194 { 195 struct rtc_plat_data *pdata = data; 196 void __iomem *ioaddr = pdata->ioaddr; 197 198 /* alarm irq? */ 199 if (!readl(ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS)) 200 return IRQ_NONE; 201 202 /* clear interrupt */ 203 writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS); 204 rtc_update_irq(pdata->rtc, 1, RTC_IRQF | RTC_AF); 205 return IRQ_HANDLED; 206 } 207 208 static const struct rtc_class_ops mv_rtc_ops = { 209 .read_time = mv_rtc_read_time, 210 .set_time = mv_rtc_set_time, 211 }; 212 213 static const struct rtc_class_ops mv_rtc_alarm_ops = { 214 .read_time = mv_rtc_read_time, 215 .set_time = mv_rtc_set_time, 216 .read_alarm = mv_rtc_read_alarm, 217 .set_alarm = mv_rtc_set_alarm, 218 .alarm_irq_enable = mv_rtc_alarm_irq_enable, 219 }; 220 221 static int __init mv_rtc_probe(struct platform_device *pdev) 222 { 223 struct resource *res; 224 struct rtc_plat_data *pdata; 225 u32 rtc_time; 226 u32 rtc_date; 227 int ret = 0; 228 229 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); 230 if (!pdata) 231 return -ENOMEM; 232 233 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 234 pdata->ioaddr = devm_ioremap_resource(&pdev->dev, res); 235 if (IS_ERR(pdata->ioaddr)) 236 return PTR_ERR(pdata->ioaddr); 237 238 pdata->clk = devm_clk_get(&pdev->dev, NULL); 239 /* Not all SoCs require a clock.*/ 240 if (!IS_ERR(pdata->clk)) 241 clk_prepare_enable(pdata->clk); 242 243 /* make sure the 24 hour mode is enabled */ 244 rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS); 245 if (rtc_time & RTC_HOURS_12H_MODE) { 246 dev_err(&pdev->dev, "12 Hour mode is enabled but not supported.\n"); 247 ret = -EINVAL; 248 goto out; 249 } 250 251 /* make sure it is actually functional */ 252 if (rtc_time == 0x01000000) { 253 ssleep(1); 254 rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS); 255 if (rtc_time == 0x01000000) { 256 dev_err(&pdev->dev, "internal RTC not ticking\n"); 257 ret = -ENODEV; 258 goto out; 259 } 260 } 261 262 /* 263 * A date after January 19th, 2038 does not fit on 32 bits and 264 * will confuse the kernel and userspace. Reset to a sane date 265 * (January 1st, 2013) if we're after 2038. 266 */ 267 rtc_date = readl(pdata->ioaddr + RTC_DATE_REG_OFFS); 268 if (bcd2bin((rtc_date >> RTC_YEAR_OFFS) & 0xff) >= 38) { 269 dev_info(&pdev->dev, "invalid RTC date, resetting to January 1st, 2013\n"); 270 writel(0x130101, pdata->ioaddr + RTC_DATE_REG_OFFS); 271 } 272 273 pdata->irq = platform_get_irq(pdev, 0); 274 275 platform_set_drvdata(pdev, pdata); 276 277 if (pdata->irq >= 0) { 278 device_init_wakeup(&pdev->dev, 1); 279 pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, 280 &mv_rtc_alarm_ops, 281 THIS_MODULE); 282 } else { 283 pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, 284 &mv_rtc_ops, THIS_MODULE); 285 } 286 if (IS_ERR(pdata->rtc)) { 287 ret = PTR_ERR(pdata->rtc); 288 goto out; 289 } 290 291 if (pdata->irq >= 0) { 292 writel(0, pdata->ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS); 293 if (devm_request_irq(&pdev->dev, pdata->irq, mv_rtc_interrupt, 294 IRQF_SHARED, 295 pdev->name, pdata) < 0) { 296 dev_warn(&pdev->dev, "interrupt not available.\n"); 297 pdata->irq = -1; 298 } 299 } 300 301 return 0; 302 out: 303 if (!IS_ERR(pdata->clk)) 304 clk_disable_unprepare(pdata->clk); 305 306 return ret; 307 } 308 309 static int __exit mv_rtc_remove(struct platform_device *pdev) 310 { 311 struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 312 313 if (pdata->irq >= 0) 314 device_init_wakeup(&pdev->dev, 0); 315 316 if (!IS_ERR(pdata->clk)) 317 clk_disable_unprepare(pdata->clk); 318 319 return 0; 320 } 321 322 #ifdef CONFIG_OF 323 static const struct of_device_id rtc_mv_of_match_table[] = { 324 { .compatible = "marvell,orion-rtc", }, 325 {} 326 }; 327 MODULE_DEVICE_TABLE(of, rtc_mv_of_match_table); 328 #endif 329 330 static struct platform_driver mv_rtc_driver = { 331 .remove = __exit_p(mv_rtc_remove), 332 .driver = { 333 .name = "rtc-mv", 334 .of_match_table = of_match_ptr(rtc_mv_of_match_table), 335 }, 336 }; 337 338 module_platform_driver_probe(mv_rtc_driver, mv_rtc_probe); 339 340 MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>"); 341 MODULE_DESCRIPTION("Marvell RTC driver"); 342 MODULE_LICENSE("GPL"); 343 MODULE_ALIAS("platform:rtc-mv"); 344