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 0; 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 alm->enabled = !!readl(ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS); 129 130 return rtc_valid_tm(&alm->time); 131 } 132 133 static int mv_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) 134 { 135 struct rtc_plat_data *pdata = dev_get_drvdata(dev); 136 void __iomem *ioaddr = pdata->ioaddr; 137 u32 rtc_reg = 0; 138 139 if (alm->time.tm_sec >= 0) 140 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_sec)) 141 << RTC_SECONDS_OFFS; 142 if (alm->time.tm_min >= 0) 143 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_min)) 144 << RTC_MINUTES_OFFS; 145 if (alm->time.tm_hour >= 0) 146 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_hour)) 147 << RTC_HOURS_OFFS; 148 149 writel(rtc_reg, ioaddr + RTC_ALARM_TIME_REG_OFFS); 150 151 if (alm->time.tm_mday >= 0) 152 rtc_reg = (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mday)) 153 << RTC_MDAY_OFFS; 154 else 155 rtc_reg = 0; 156 157 if (alm->time.tm_mon >= 0) 158 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mon + 1)) 159 << RTC_MONTH_OFFS; 160 161 if (alm->time.tm_year >= 0) 162 rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_year % 100)) 163 << RTC_YEAR_OFFS; 164 165 writel(rtc_reg, ioaddr + RTC_ALARM_DATE_REG_OFFS); 166 writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS); 167 writel(alm->enabled ? 1 : 0, 168 ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS); 169 170 return 0; 171 } 172 173 static int mv_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) 174 { 175 struct rtc_plat_data *pdata = dev_get_drvdata(dev); 176 void __iomem *ioaddr = pdata->ioaddr; 177 178 if (pdata->irq < 0) 179 return -EINVAL; /* fall back into rtc-dev's emulation */ 180 181 if (enabled) 182 writel(1, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS); 183 else 184 writel(0, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS); 185 return 0; 186 } 187 188 static irqreturn_t mv_rtc_interrupt(int irq, void *data) 189 { 190 struct rtc_plat_data *pdata = data; 191 void __iomem *ioaddr = pdata->ioaddr; 192 193 /* alarm irq? */ 194 if (!readl(ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS)) 195 return IRQ_NONE; 196 197 /* clear interrupt */ 198 writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS); 199 rtc_update_irq(pdata->rtc, 1, RTC_IRQF | RTC_AF); 200 return IRQ_HANDLED; 201 } 202 203 static const struct rtc_class_ops mv_rtc_ops = { 204 .read_time = mv_rtc_read_time, 205 .set_time = mv_rtc_set_time, 206 }; 207 208 static const struct rtc_class_ops mv_rtc_alarm_ops = { 209 .read_time = mv_rtc_read_time, 210 .set_time = mv_rtc_set_time, 211 .read_alarm = mv_rtc_read_alarm, 212 .set_alarm = mv_rtc_set_alarm, 213 .alarm_irq_enable = mv_rtc_alarm_irq_enable, 214 }; 215 216 static int __init mv_rtc_probe(struct platform_device *pdev) 217 { 218 struct resource *res; 219 struct rtc_plat_data *pdata; 220 u32 rtc_time; 221 int ret = 0; 222 223 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); 224 if (!pdata) 225 return -ENOMEM; 226 227 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 228 pdata->ioaddr = devm_ioremap_resource(&pdev->dev, res); 229 if (IS_ERR(pdata->ioaddr)) 230 return PTR_ERR(pdata->ioaddr); 231 232 pdata->clk = devm_clk_get(&pdev->dev, NULL); 233 /* Not all SoCs require a clock.*/ 234 if (!IS_ERR(pdata->clk)) 235 clk_prepare_enable(pdata->clk); 236 237 /* make sure the 24 hour mode is enabled */ 238 rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS); 239 if (rtc_time & RTC_HOURS_12H_MODE) { 240 dev_err(&pdev->dev, "12 Hour mode is enabled but not supported.\n"); 241 ret = -EINVAL; 242 goto out; 243 } 244 245 /* make sure it is actually functional */ 246 if (rtc_time == 0x01000000) { 247 ssleep(1); 248 rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS); 249 if (rtc_time == 0x01000000) { 250 dev_err(&pdev->dev, "internal RTC not ticking\n"); 251 ret = -ENODEV; 252 goto out; 253 } 254 } 255 256 pdata->irq = platform_get_irq(pdev, 0); 257 258 platform_set_drvdata(pdev, pdata); 259 260 if (pdata->irq >= 0) { 261 device_init_wakeup(&pdev->dev, 1); 262 pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, 263 &mv_rtc_alarm_ops, 264 THIS_MODULE); 265 } else { 266 pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, 267 &mv_rtc_ops, THIS_MODULE); 268 } 269 if (IS_ERR(pdata->rtc)) { 270 ret = PTR_ERR(pdata->rtc); 271 goto out; 272 } 273 274 if (pdata->irq >= 0) { 275 writel(0, pdata->ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS); 276 if (devm_request_irq(&pdev->dev, pdata->irq, mv_rtc_interrupt, 277 IRQF_SHARED, 278 pdev->name, pdata) < 0) { 279 dev_warn(&pdev->dev, "interrupt not available.\n"); 280 pdata->irq = -1; 281 } 282 } 283 284 return 0; 285 out: 286 if (!IS_ERR(pdata->clk)) 287 clk_disable_unprepare(pdata->clk); 288 289 return ret; 290 } 291 292 static int __exit mv_rtc_remove(struct platform_device *pdev) 293 { 294 struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 295 296 if (pdata->irq >= 0) 297 device_init_wakeup(&pdev->dev, 0); 298 299 if (!IS_ERR(pdata->clk)) 300 clk_disable_unprepare(pdata->clk); 301 302 return 0; 303 } 304 305 #ifdef CONFIG_OF 306 static const struct of_device_id rtc_mv_of_match_table[] = { 307 { .compatible = "marvell,orion-rtc", }, 308 {} 309 }; 310 MODULE_DEVICE_TABLE(of, rtc_mv_of_match_table); 311 #endif 312 313 static struct platform_driver mv_rtc_driver = { 314 .remove = __exit_p(mv_rtc_remove), 315 .driver = { 316 .name = "rtc-mv", 317 .of_match_table = of_match_ptr(rtc_mv_of_match_table), 318 }, 319 }; 320 321 module_platform_driver_probe(mv_rtc_driver, mv_rtc_probe); 322 323 MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>"); 324 MODULE_DESCRIPTION("Marvell RTC driver"); 325 MODULE_LICENSE("GPL"); 326 MODULE_ALIAS("platform:rtc-mv"); 327