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 struct vt8500_rtc { 78 void __iomem *regbase; 79 struct resource *res; 80 int irq_alarm; 81 struct rtc_device *rtc; 82 spinlock_t lock; /* Protects this structure */ 83 }; 84 85 static irqreturn_t vt8500_rtc_irq(int irq, void *dev_id) 86 { 87 struct vt8500_rtc *vt8500_rtc = dev_id; 88 u32 isr; 89 unsigned long events = 0; 90 91 spin_lock(&vt8500_rtc->lock); 92 93 /* clear interrupt sources */ 94 isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS); 95 writel(isr, vt8500_rtc->regbase + VT8500_RTC_IS); 96 97 spin_unlock(&vt8500_rtc->lock); 98 99 if (isr & 1) 100 events |= RTC_AF | RTC_IRQF; 101 102 rtc_update_irq(vt8500_rtc->rtc, 1, events); 103 104 return IRQ_HANDLED; 105 } 106 107 static int vt8500_rtc_read_time(struct device *dev, struct rtc_time *tm) 108 { 109 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); 110 u32 date, time; 111 112 date = readl(vt8500_rtc->regbase + VT8500_RTC_DR); 113 time = readl(vt8500_rtc->regbase + VT8500_RTC_TR); 114 115 tm->tm_sec = bcd2bin(time & TIME_SEC_MASK); 116 tm->tm_min = bcd2bin((time & TIME_MIN_MASK) >> TIME_MIN_S); 117 tm->tm_hour = bcd2bin((time & TIME_HOUR_MASK) >> TIME_HOUR_S); 118 tm->tm_mday = bcd2bin(date & DATE_DAY_MASK); 119 tm->tm_mon = bcd2bin((date & DATE_MONTH_MASK) >> DATE_MONTH_S); 120 tm->tm_year = bcd2bin((date & DATE_YEAR_MASK) >> DATE_YEAR_S) 121 + ((date >> DATE_CENTURY_S) & 1 ? 200 : 100); 122 tm->tm_wday = (time & TIME_DOW_MASK) >> TIME_DOW_S; 123 124 return 0; 125 } 126 127 static int vt8500_rtc_set_time(struct device *dev, struct rtc_time *tm) 128 { 129 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); 130 131 if (tm->tm_year < 100) { 132 dev_warn(dev, "Only years 2000-2199 are supported by the " 133 "hardware!\n"); 134 return -EINVAL; 135 } 136 137 writel((bin2bcd(tm->tm_year - 100) << DATE_YEAR_S) 138 | (bin2bcd(tm->tm_mon) << DATE_MONTH_S) 139 | (bin2bcd(tm->tm_mday)), 140 vt8500_rtc->regbase + VT8500_RTC_DS); 141 writel((bin2bcd(tm->tm_wday) << TIME_DOW_S) 142 | (bin2bcd(tm->tm_hour) << TIME_HOUR_S) 143 | (bin2bcd(tm->tm_min) << TIME_MIN_S) 144 | (bin2bcd(tm->tm_sec)), 145 vt8500_rtc->regbase + VT8500_RTC_TS); 146 147 return 0; 148 } 149 150 static int vt8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 151 { 152 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); 153 u32 isr, alarm; 154 155 alarm = readl(vt8500_rtc->regbase + VT8500_RTC_AS); 156 isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS); 157 158 alrm->time.tm_mday = bcd2bin((alarm & ALARM_DAY_MASK) >> ALARM_DAY_S); 159 alrm->time.tm_hour = bcd2bin((alarm & TIME_HOUR_MASK) >> TIME_HOUR_S); 160 alrm->time.tm_min = bcd2bin((alarm & TIME_MIN_MASK) >> TIME_MIN_S); 161 alrm->time.tm_sec = bcd2bin((alarm & TIME_SEC_MASK)); 162 163 alrm->enabled = (alarm & ALARM_ENABLE_MASK) ? 1 : 0; 164 165 alrm->pending = (isr & 1) ? 1 : 0; 166 return rtc_valid_tm(&alrm->time); 167 } 168 169 static int vt8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 170 { 171 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); 172 173 writel((alrm->enabled ? ALARM_ENABLE_MASK : 0) 174 | (bin2bcd(alrm->time.tm_mday) << ALARM_DAY_S) 175 | (bin2bcd(alrm->time.tm_hour) << TIME_HOUR_S) 176 | (bin2bcd(alrm->time.tm_min) << TIME_MIN_S) 177 | (bin2bcd(alrm->time.tm_sec)), 178 vt8500_rtc->regbase + VT8500_RTC_AS); 179 180 return 0; 181 } 182 183 static int vt8500_alarm_irq_enable(struct device *dev, unsigned int enabled) 184 { 185 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); 186 unsigned long tmp = readl(vt8500_rtc->regbase + VT8500_RTC_AS); 187 188 if (enabled) 189 tmp |= ALARM_ENABLE_MASK; 190 else 191 tmp &= ~ALARM_ENABLE_MASK; 192 193 writel(tmp, vt8500_rtc->regbase + VT8500_RTC_AS); 194 return 0; 195 } 196 197 static const struct rtc_class_ops vt8500_rtc_ops = { 198 .read_time = vt8500_rtc_read_time, 199 .set_time = vt8500_rtc_set_time, 200 .read_alarm = vt8500_rtc_read_alarm, 201 .set_alarm = vt8500_rtc_set_alarm, 202 .alarm_irq_enable = vt8500_alarm_irq_enable, 203 }; 204 205 static int __devinit vt8500_rtc_probe(struct platform_device *pdev) 206 { 207 struct vt8500_rtc *vt8500_rtc; 208 int ret; 209 210 vt8500_rtc = kzalloc(sizeof(struct vt8500_rtc), GFP_KERNEL); 211 if (!vt8500_rtc) 212 return -ENOMEM; 213 214 spin_lock_init(&vt8500_rtc->lock); 215 platform_set_drvdata(pdev, vt8500_rtc); 216 217 vt8500_rtc->res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 218 if (!vt8500_rtc->res) { 219 dev_err(&pdev->dev, "No I/O memory resource defined\n"); 220 ret = -ENXIO; 221 goto err_free; 222 } 223 224 vt8500_rtc->irq_alarm = platform_get_irq(pdev, 0); 225 if (vt8500_rtc->irq_alarm < 0) { 226 dev_err(&pdev->dev, "No alarm IRQ resource defined\n"); 227 ret = -ENXIO; 228 goto err_free; 229 } 230 231 vt8500_rtc->res = request_mem_region(vt8500_rtc->res->start, 232 resource_size(vt8500_rtc->res), 233 "vt8500-rtc"); 234 if (vt8500_rtc->res == NULL) { 235 dev_err(&pdev->dev, "failed to request I/O memory\n"); 236 ret = -EBUSY; 237 goto err_free; 238 } 239 240 vt8500_rtc->regbase = ioremap(vt8500_rtc->res->start, 241 resource_size(vt8500_rtc->res)); 242 if (!vt8500_rtc->regbase) { 243 dev_err(&pdev->dev, "Unable to map RTC I/O memory\n"); 244 ret = -EBUSY; 245 goto err_release; 246 } 247 248 /* Enable RTC and set it to 24-hour mode */ 249 writel(VT8500_RTC_CR_ENABLE | VT8500_RTC_CR_24H, 250 vt8500_rtc->regbase + VT8500_RTC_CR); 251 252 vt8500_rtc->rtc = rtc_device_register("vt8500-rtc", &pdev->dev, 253 &vt8500_rtc_ops, THIS_MODULE); 254 if (IS_ERR(vt8500_rtc->rtc)) { 255 ret = PTR_ERR(vt8500_rtc->rtc); 256 dev_err(&pdev->dev, 257 "Failed to register RTC device -> %d\n", ret); 258 goto err_unmap; 259 } 260 261 ret = request_irq(vt8500_rtc->irq_alarm, vt8500_rtc_irq, 0, 262 "rtc alarm", vt8500_rtc); 263 if (ret < 0) { 264 dev_err(&pdev->dev, "can't get irq %i, err %d\n", 265 vt8500_rtc->irq_alarm, ret); 266 goto err_unreg; 267 } 268 269 return 0; 270 271 err_unreg: 272 rtc_device_unregister(vt8500_rtc->rtc); 273 err_unmap: 274 iounmap(vt8500_rtc->regbase); 275 err_release: 276 release_mem_region(vt8500_rtc->res->start, 277 resource_size(vt8500_rtc->res)); 278 err_free: 279 kfree(vt8500_rtc); 280 return ret; 281 } 282 283 static int __devexit vt8500_rtc_remove(struct platform_device *pdev) 284 { 285 struct vt8500_rtc *vt8500_rtc = platform_get_drvdata(pdev); 286 287 free_irq(vt8500_rtc->irq_alarm, vt8500_rtc); 288 289 rtc_device_unregister(vt8500_rtc->rtc); 290 291 /* Disable alarm matching */ 292 writel(0, vt8500_rtc->regbase + VT8500_RTC_IS); 293 iounmap(vt8500_rtc->regbase); 294 release_mem_region(vt8500_rtc->res->start, 295 resource_size(vt8500_rtc->res)); 296 297 kfree(vt8500_rtc); 298 platform_set_drvdata(pdev, NULL); 299 300 return 0; 301 } 302 303 static struct platform_driver vt8500_rtc_driver = { 304 .probe = vt8500_rtc_probe, 305 .remove = __devexit_p(vt8500_rtc_remove), 306 .driver = { 307 .name = "vt8500-rtc", 308 .owner = THIS_MODULE, 309 }, 310 }; 311 312 static int __init vt8500_rtc_init(void) 313 { 314 return platform_driver_register(&vt8500_rtc_driver); 315 } 316 module_init(vt8500_rtc_init); 317 318 static void __exit vt8500_rtc_exit(void) 319 { 320 platform_driver_unregister(&vt8500_rtc_driver); 321 } 322 module_exit(vt8500_rtc_exit); 323 324 MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>"); 325 MODULE_DESCRIPTION("VIA VT8500 SoC Realtime Clock Driver (RTC)"); 326 MODULE_LICENSE("GPL"); 327 MODULE_ALIAS("platform:vt8500-rtc"); 328