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 27 /* 28 * Register definitions 29 */ 30 #define VT8500_RTC_TS 0x00 /* Time set */ 31 #define VT8500_RTC_DS 0x04 /* Date set */ 32 #define VT8500_RTC_AS 0x08 /* Alarm set */ 33 #define VT8500_RTC_CR 0x0c /* Control */ 34 #define VT8500_RTC_TR 0x10 /* Time read */ 35 #define VT8500_RTC_DR 0x14 /* Date read */ 36 #define VT8500_RTC_WS 0x18 /* Write status */ 37 #define VT8500_RTC_CL 0x20 /* Calibration */ 38 #define VT8500_RTC_IS 0x24 /* Interrupt status */ 39 #define VT8500_RTC_ST 0x28 /* Status */ 40 41 #define INVALID_TIME_BIT (1 << 31) 42 43 #define DATE_CENTURY_S 19 44 #define DATE_YEAR_S 11 45 #define DATE_YEAR_MASK (0xff << DATE_YEAR_S) 46 #define DATE_MONTH_S 6 47 #define DATE_MONTH_MASK (0x1f << DATE_MONTH_S) 48 #define DATE_DAY_MASK 0x3f 49 50 #define TIME_DOW_S 20 51 #define TIME_DOW_MASK (0x07 << TIME_DOW_S) 52 #define TIME_HOUR_S 14 53 #define TIME_HOUR_MASK (0x3f << TIME_HOUR_S) 54 #define TIME_MIN_S 7 55 #define TIME_MIN_MASK (0x7f << TIME_MIN_S) 56 #define TIME_SEC_MASK 0x7f 57 58 #define ALARM_DAY_S 20 59 #define ALARM_DAY_MASK (0x3f << ALARM_DAY_S) 60 61 #define ALARM_DAY_BIT (1 << 29) 62 #define ALARM_HOUR_BIT (1 << 28) 63 #define ALARM_MIN_BIT (1 << 27) 64 #define ALARM_SEC_BIT (1 << 26) 65 66 #define ALARM_ENABLE_MASK (ALARM_DAY_BIT \ 67 | ALARM_HOUR_BIT \ 68 | ALARM_MIN_BIT \ 69 | ALARM_SEC_BIT) 70 71 #define VT8500_RTC_CR_ENABLE (1 << 0) /* Enable RTC */ 72 #define VT8500_RTC_CR_24H (1 << 1) /* 24h time format */ 73 #define VT8500_RTC_CR_SM_ENABLE (1 << 2) /* Enable periodic irqs */ 74 #define VT8500_RTC_CR_SM_SEC (1 << 3) /* 0: 1Hz/60, 1: 1Hz */ 75 #define VT8500_RTC_CR_CALIB (1 << 4) /* Enable calibration */ 76 77 #define VT8500_RTC_IS_ALARM (1 << 0) /* Alarm interrupt status */ 78 79 struct vt8500_rtc { 80 void __iomem *regbase; 81 struct resource *res; 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); 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) << DATE_MONTH_S) 141 | (bin2bcd(tm->tm_mday)), 142 vt8500_rtc->regbase + VT8500_RTC_DS); 143 writel((bin2bcd(tm->tm_wday) << TIME_DOW_S) 144 | (bin2bcd(tm->tm_hour) << TIME_HOUR_S) 145 | (bin2bcd(tm->tm_min) << TIME_MIN_S) 146 | (bin2bcd(tm->tm_sec)), 147 vt8500_rtc->regbase + VT8500_RTC_TS); 148 149 return 0; 150 } 151 152 static int vt8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 153 { 154 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); 155 u32 isr, alarm; 156 157 alarm = readl(vt8500_rtc->regbase + VT8500_RTC_AS); 158 isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS); 159 160 alrm->time.tm_mday = bcd2bin((alarm & ALARM_DAY_MASK) >> ALARM_DAY_S); 161 alrm->time.tm_hour = bcd2bin((alarm & TIME_HOUR_MASK) >> TIME_HOUR_S); 162 alrm->time.tm_min = bcd2bin((alarm & TIME_MIN_MASK) >> TIME_MIN_S); 163 alrm->time.tm_sec = bcd2bin((alarm & TIME_SEC_MASK)); 164 165 alrm->enabled = (alarm & ALARM_ENABLE_MASK) ? 1 : 0; 166 alrm->pending = (isr & VT8500_RTC_IS_ALARM) ? 1 : 0; 167 168 return rtc_valid_tm(&alrm->time); 169 } 170 171 static int vt8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 172 { 173 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); 174 175 writel((alrm->enabled ? ALARM_ENABLE_MASK : 0) 176 | (bin2bcd(alrm->time.tm_mday) << ALARM_DAY_S) 177 | (bin2bcd(alrm->time.tm_hour) << TIME_HOUR_S) 178 | (bin2bcd(alrm->time.tm_min) << TIME_MIN_S) 179 | (bin2bcd(alrm->time.tm_sec)), 180 vt8500_rtc->regbase + VT8500_RTC_AS); 181 182 return 0; 183 } 184 185 static int vt8500_alarm_irq_enable(struct device *dev, unsigned int enabled) 186 { 187 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); 188 unsigned long tmp = readl(vt8500_rtc->regbase + VT8500_RTC_AS); 189 190 if (enabled) 191 tmp |= ALARM_ENABLE_MASK; 192 else 193 tmp &= ~ALARM_ENABLE_MASK; 194 195 writel(tmp, vt8500_rtc->regbase + VT8500_RTC_AS); 196 return 0; 197 } 198 199 static const struct rtc_class_ops vt8500_rtc_ops = { 200 .read_time = vt8500_rtc_read_time, 201 .set_time = vt8500_rtc_set_time, 202 .read_alarm = vt8500_rtc_read_alarm, 203 .set_alarm = vt8500_rtc_set_alarm, 204 .alarm_irq_enable = vt8500_alarm_irq_enable, 205 }; 206 207 static int __devinit vt8500_rtc_probe(struct platform_device *pdev) 208 { 209 struct vt8500_rtc *vt8500_rtc; 210 int ret; 211 212 vt8500_rtc = kzalloc(sizeof(struct vt8500_rtc), GFP_KERNEL); 213 if (!vt8500_rtc) 214 return -ENOMEM; 215 216 spin_lock_init(&vt8500_rtc->lock); 217 platform_set_drvdata(pdev, vt8500_rtc); 218 219 vt8500_rtc->res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 220 if (!vt8500_rtc->res) { 221 dev_err(&pdev->dev, "No I/O memory resource defined\n"); 222 ret = -ENXIO; 223 goto err_free; 224 } 225 226 vt8500_rtc->irq_alarm = platform_get_irq(pdev, 0); 227 if (vt8500_rtc->irq_alarm < 0) { 228 dev_err(&pdev->dev, "No alarm IRQ resource defined\n"); 229 ret = -ENXIO; 230 goto err_free; 231 } 232 233 vt8500_rtc->res = request_mem_region(vt8500_rtc->res->start, 234 resource_size(vt8500_rtc->res), 235 "vt8500-rtc"); 236 if (vt8500_rtc->res == NULL) { 237 dev_err(&pdev->dev, "failed to request I/O memory\n"); 238 ret = -EBUSY; 239 goto err_free; 240 } 241 242 vt8500_rtc->regbase = ioremap(vt8500_rtc->res->start, 243 resource_size(vt8500_rtc->res)); 244 if (!vt8500_rtc->regbase) { 245 dev_err(&pdev->dev, "Unable to map RTC I/O memory\n"); 246 ret = -EBUSY; 247 goto err_release; 248 } 249 250 /* Enable RTC and set it to 24-hour mode */ 251 writel(VT8500_RTC_CR_ENABLE | VT8500_RTC_CR_24H, 252 vt8500_rtc->regbase + VT8500_RTC_CR); 253 254 vt8500_rtc->rtc = rtc_device_register("vt8500-rtc", &pdev->dev, 255 &vt8500_rtc_ops, THIS_MODULE); 256 if (IS_ERR(vt8500_rtc->rtc)) { 257 ret = PTR_ERR(vt8500_rtc->rtc); 258 dev_err(&pdev->dev, 259 "Failed to register RTC device -> %d\n", ret); 260 goto err_unmap; 261 } 262 263 ret = request_irq(vt8500_rtc->irq_alarm, vt8500_rtc_irq, 0, 264 "rtc alarm", vt8500_rtc); 265 if (ret < 0) { 266 dev_err(&pdev->dev, "can't get irq %i, err %d\n", 267 vt8500_rtc->irq_alarm, ret); 268 goto err_unreg; 269 } 270 271 return 0; 272 273 err_unreg: 274 rtc_device_unregister(vt8500_rtc->rtc); 275 err_unmap: 276 iounmap(vt8500_rtc->regbase); 277 err_release: 278 release_mem_region(vt8500_rtc->res->start, 279 resource_size(vt8500_rtc->res)); 280 err_free: 281 kfree(vt8500_rtc); 282 return ret; 283 } 284 285 static int __devexit vt8500_rtc_remove(struct platform_device *pdev) 286 { 287 struct vt8500_rtc *vt8500_rtc = platform_get_drvdata(pdev); 288 289 free_irq(vt8500_rtc->irq_alarm, vt8500_rtc); 290 291 rtc_device_unregister(vt8500_rtc->rtc); 292 293 /* Disable alarm matching */ 294 writel(0, vt8500_rtc->regbase + VT8500_RTC_IS); 295 iounmap(vt8500_rtc->regbase); 296 release_mem_region(vt8500_rtc->res->start, 297 resource_size(vt8500_rtc->res)); 298 299 kfree(vt8500_rtc); 300 platform_set_drvdata(pdev, NULL); 301 302 return 0; 303 } 304 305 static struct platform_driver vt8500_rtc_driver = { 306 .probe = vt8500_rtc_probe, 307 .remove = __devexit_p(vt8500_rtc_remove), 308 .driver = { 309 .name = "vt8500-rtc", 310 .owner = THIS_MODULE, 311 }, 312 }; 313 314 module_platform_driver(vt8500_rtc_driver); 315 316 MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>"); 317 MODULE_DESCRIPTION("VIA VT8500 SoC Realtime Clock Driver (RTC)"); 318 MODULE_LICENSE("GPL"); 319 MODULE_ALIAS("platform:vt8500-rtc"); 320