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 int irq_hz; 82 struct rtc_device *rtc; 83 spinlock_t lock; /* Protects this structure */ 84 }; 85 86 static irqreturn_t vt8500_rtc_irq(int irq, void *dev_id) 87 { 88 struct vt8500_rtc *vt8500_rtc = dev_id; 89 u32 isr; 90 unsigned long events = 0; 91 92 spin_lock(&vt8500_rtc->lock); 93 94 /* clear interrupt sources */ 95 isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS); 96 writel(isr, vt8500_rtc->regbase + VT8500_RTC_IS); 97 98 spin_unlock(&vt8500_rtc->lock); 99 100 if (isr & 1) 101 events |= RTC_AF | RTC_IRQF; 102 103 /* Only second/minute interrupts are supported */ 104 if (isr & 2) 105 events |= RTC_UF | RTC_IRQF; 106 107 rtc_update_irq(vt8500_rtc->rtc, 1, events); 108 109 return IRQ_HANDLED; 110 } 111 112 static int vt8500_rtc_read_time(struct device *dev, struct rtc_time *tm) 113 { 114 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); 115 u32 date, time; 116 117 date = readl(vt8500_rtc->regbase + VT8500_RTC_DR); 118 time = readl(vt8500_rtc->regbase + VT8500_RTC_TR); 119 120 tm->tm_sec = bcd2bin(time & TIME_SEC_MASK); 121 tm->tm_min = bcd2bin((time & TIME_MIN_MASK) >> TIME_MIN_S); 122 tm->tm_hour = bcd2bin((time & TIME_HOUR_MASK) >> TIME_HOUR_S); 123 tm->tm_mday = bcd2bin(date & DATE_DAY_MASK); 124 tm->tm_mon = bcd2bin((date & DATE_MONTH_MASK) >> DATE_MONTH_S); 125 tm->tm_year = bcd2bin((date & DATE_YEAR_MASK) >> DATE_YEAR_S) 126 + ((date >> DATE_CENTURY_S) & 1 ? 200 : 100); 127 tm->tm_wday = (time & TIME_DOW_MASK) >> TIME_DOW_S; 128 129 return 0; 130 } 131 132 static int vt8500_rtc_set_time(struct device *dev, struct rtc_time *tm) 133 { 134 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); 135 136 if (tm->tm_year < 100) { 137 dev_warn(dev, "Only years 2000-2199 are supported by the " 138 "hardware!\n"); 139 return -EINVAL; 140 } 141 142 writel((bin2bcd(tm->tm_year - 100) << DATE_YEAR_S) 143 | (bin2bcd(tm->tm_mon) << DATE_MONTH_S) 144 | (bin2bcd(tm->tm_mday)), 145 vt8500_rtc->regbase + VT8500_RTC_DS); 146 writel((bin2bcd(tm->tm_wday) << TIME_DOW_S) 147 | (bin2bcd(tm->tm_hour) << TIME_HOUR_S) 148 | (bin2bcd(tm->tm_min) << TIME_MIN_S) 149 | (bin2bcd(tm->tm_sec)), 150 vt8500_rtc->regbase + VT8500_RTC_TS); 151 152 return 0; 153 } 154 155 static int vt8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 156 { 157 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); 158 u32 isr, alarm; 159 160 alarm = readl(vt8500_rtc->regbase + VT8500_RTC_AS); 161 isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS); 162 163 alrm->time.tm_mday = bcd2bin((alarm & ALARM_DAY_MASK) >> ALARM_DAY_S); 164 alrm->time.tm_hour = bcd2bin((alarm & TIME_HOUR_MASK) >> TIME_HOUR_S); 165 alrm->time.tm_min = bcd2bin((alarm & TIME_MIN_MASK) >> TIME_MIN_S); 166 alrm->time.tm_sec = bcd2bin((alarm & TIME_SEC_MASK)); 167 168 alrm->enabled = (alarm & ALARM_ENABLE_MASK) ? 1 : 0; 169 170 alrm->pending = (isr & 1) ? 1 : 0; 171 return rtc_valid_tm(&alrm->time); 172 } 173 174 static int vt8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 175 { 176 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); 177 178 writel((alrm->enabled ? ALARM_ENABLE_MASK : 0) 179 | (bin2bcd(alrm->time.tm_mday) << ALARM_DAY_S) 180 | (bin2bcd(alrm->time.tm_hour) << TIME_HOUR_S) 181 | (bin2bcd(alrm->time.tm_min) << TIME_MIN_S) 182 | (bin2bcd(alrm->time.tm_sec)), 183 vt8500_rtc->regbase + VT8500_RTC_AS); 184 185 return 0; 186 } 187 188 static int vt8500_alarm_irq_enable(struct device *dev, unsigned int enabled) 189 { 190 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); 191 unsigned long tmp = readl(vt8500_rtc->regbase + VT8500_RTC_AS); 192 193 if (enabled) 194 tmp |= ALARM_ENABLE_MASK; 195 else 196 tmp &= ~ALARM_ENABLE_MASK; 197 198 writel(tmp, vt8500_rtc->regbase + VT8500_RTC_AS); 199 return 0; 200 } 201 202 static int vt8500_update_irq_enable(struct device *dev, unsigned int enabled) 203 { 204 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev); 205 unsigned long tmp = readl(vt8500_rtc->regbase + VT8500_RTC_CR); 206 207 if (enabled) 208 tmp |= VT8500_RTC_CR_SM_SEC | VT8500_RTC_CR_SM_ENABLE; 209 else 210 tmp &= ~VT8500_RTC_CR_SM_ENABLE; 211 212 writel(tmp, vt8500_rtc->regbase + VT8500_RTC_CR); 213 return 0; 214 } 215 216 static const struct rtc_class_ops vt8500_rtc_ops = { 217 .read_time = vt8500_rtc_read_time, 218 .set_time = vt8500_rtc_set_time, 219 .read_alarm = vt8500_rtc_read_alarm, 220 .set_alarm = vt8500_rtc_set_alarm, 221 .alarm_irq_enable = vt8500_alarm_irq_enable, 222 .update_irq_enable = vt8500_update_irq_enable, 223 }; 224 225 static int __devinit vt8500_rtc_probe(struct platform_device *pdev) 226 { 227 struct vt8500_rtc *vt8500_rtc; 228 int ret; 229 230 vt8500_rtc = kzalloc(sizeof(struct vt8500_rtc), GFP_KERNEL); 231 if (!vt8500_rtc) 232 return -ENOMEM; 233 234 spin_lock_init(&vt8500_rtc->lock); 235 platform_set_drvdata(pdev, vt8500_rtc); 236 237 vt8500_rtc->res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 238 if (!vt8500_rtc->res) { 239 dev_err(&pdev->dev, "No I/O memory resource defined\n"); 240 ret = -ENXIO; 241 goto err_free; 242 } 243 244 vt8500_rtc->irq_alarm = platform_get_irq(pdev, 0); 245 if (vt8500_rtc->irq_alarm < 0) { 246 dev_err(&pdev->dev, "No alarm IRQ resource defined\n"); 247 ret = -ENXIO; 248 goto err_free; 249 } 250 251 vt8500_rtc->irq_hz = platform_get_irq(pdev, 1); 252 if (vt8500_rtc->irq_hz < 0) { 253 dev_err(&pdev->dev, "No 1Hz IRQ resource defined\n"); 254 ret = -ENXIO; 255 goto err_free; 256 } 257 258 vt8500_rtc->res = request_mem_region(vt8500_rtc->res->start, 259 resource_size(vt8500_rtc->res), 260 "vt8500-rtc"); 261 if (vt8500_rtc->res == NULL) { 262 dev_err(&pdev->dev, "failed to request I/O memory\n"); 263 ret = -EBUSY; 264 goto err_free; 265 } 266 267 vt8500_rtc->regbase = ioremap(vt8500_rtc->res->start, 268 resource_size(vt8500_rtc->res)); 269 if (!vt8500_rtc->regbase) { 270 dev_err(&pdev->dev, "Unable to map RTC I/O memory\n"); 271 ret = -EBUSY; 272 goto err_release; 273 } 274 275 /* Enable the second/minute interrupt generation and enable RTC */ 276 writel(VT8500_RTC_CR_ENABLE | VT8500_RTC_CR_24H 277 | VT8500_RTC_CR_SM_ENABLE | VT8500_RTC_CR_SM_SEC, 278 vt8500_rtc->regbase + VT8500_RTC_CR); 279 280 vt8500_rtc->rtc = rtc_device_register("vt8500-rtc", &pdev->dev, 281 &vt8500_rtc_ops, THIS_MODULE); 282 if (IS_ERR(vt8500_rtc->rtc)) { 283 ret = PTR_ERR(vt8500_rtc->rtc); 284 dev_err(&pdev->dev, 285 "Failed to register RTC device -> %d\n", ret); 286 goto err_unmap; 287 } 288 289 ret = request_irq(vt8500_rtc->irq_hz, vt8500_rtc_irq, 0, 290 "rtc 1Hz", vt8500_rtc); 291 if (ret < 0) { 292 dev_err(&pdev->dev, "can't get irq %i, err %d\n", 293 vt8500_rtc->irq_hz, ret); 294 goto err_unreg; 295 } 296 297 ret = request_irq(vt8500_rtc->irq_alarm, vt8500_rtc_irq, 0, 298 "rtc alarm", vt8500_rtc); 299 if (ret < 0) { 300 dev_err(&pdev->dev, "can't get irq %i, err %d\n", 301 vt8500_rtc->irq_alarm, ret); 302 goto err_free_hz; 303 } 304 305 return 0; 306 307 err_free_hz: 308 free_irq(vt8500_rtc->irq_hz, vt8500_rtc); 309 err_unreg: 310 rtc_device_unregister(vt8500_rtc->rtc); 311 err_unmap: 312 iounmap(vt8500_rtc->regbase); 313 err_release: 314 release_mem_region(vt8500_rtc->res->start, 315 resource_size(vt8500_rtc->res)); 316 err_free: 317 kfree(vt8500_rtc); 318 return ret; 319 } 320 321 static int __devexit vt8500_rtc_remove(struct platform_device *pdev) 322 { 323 struct vt8500_rtc *vt8500_rtc = platform_get_drvdata(pdev); 324 325 free_irq(vt8500_rtc->irq_alarm, vt8500_rtc); 326 free_irq(vt8500_rtc->irq_hz, vt8500_rtc); 327 328 rtc_device_unregister(vt8500_rtc->rtc); 329 330 /* Disable alarm matching */ 331 writel(0, vt8500_rtc->regbase + VT8500_RTC_IS); 332 iounmap(vt8500_rtc->regbase); 333 release_mem_region(vt8500_rtc->res->start, 334 resource_size(vt8500_rtc->res)); 335 336 kfree(vt8500_rtc); 337 platform_set_drvdata(pdev, NULL); 338 339 return 0; 340 } 341 342 static struct platform_driver vt8500_rtc_driver = { 343 .probe = vt8500_rtc_probe, 344 .remove = __devexit_p(vt8500_rtc_remove), 345 .driver = { 346 .name = "vt8500-rtc", 347 .owner = THIS_MODULE, 348 }, 349 }; 350 351 static int __init vt8500_rtc_init(void) 352 { 353 return platform_driver_register(&vt8500_rtc_driver); 354 } 355 module_init(vt8500_rtc_init); 356 357 static void __exit vt8500_rtc_exit(void) 358 { 359 platform_driver_unregister(&vt8500_rtc_driver); 360 } 361 module_exit(vt8500_rtc_exit); 362 363 MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>"); 364 MODULE_DESCRIPTION("VIA VT8500 SoC Realtime Clock Driver (RTC)"); 365 MODULE_LICENSE("GPL"); 366 MODULE_ALIAS("platform:vt8500-rtc"); 367