1 /* 2 * RTC driver for Maxim MAX8925 3 * 4 * Copyright (C) 2009-2010 Marvell International Ltd. 5 * Haojian Zhuang <haojian.zhuang@marvell.com> 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 */ 11 12 #include <linux/module.h> 13 #include <linux/i2c.h> 14 #include <linux/slab.h> 15 #include <linux/rtc.h> 16 #include <linux/platform_device.h> 17 #include <linux/mfd/max8925.h> 18 19 enum { 20 RTC_SEC = 0, 21 RTC_MIN, 22 RTC_HOUR, 23 RTC_WEEKDAY, 24 RTC_DATE, 25 RTC_MONTH, 26 RTC_YEAR1, 27 RTC_YEAR2, 28 }; 29 30 #define MAX8925_RTC_SEC 0x00 31 #define MAX8925_RTC_MIN 0x01 32 #define MAX8925_RTC_HOUR 0x02 33 #define MAX8925_RTC_WEEKDAY 0x03 34 #define MAX8925_RTC_DATE 0x04 35 #define MAX8925_RTC_MONTH 0x05 36 #define MAX8925_RTC_YEAR1 0x06 37 #define MAX8925_RTC_YEAR2 0x07 38 #define MAX8925_ALARM0_SEC 0x08 39 #define MAX8925_ALARM0_MIN 0x09 40 #define MAX8925_ALARM0_HOUR 0x0a 41 #define MAX8925_ALARM0_WEEKDAY 0x0b 42 #define MAX8925_ALARM0_DATE 0x0c 43 #define MAX8925_ALARM0_MON 0x0d 44 #define MAX8925_ALARM0_YEAR1 0x0e 45 #define MAX8925_ALARM0_YEAR2 0x0f 46 #define MAX8925_ALARM1_SEC 0x10 47 #define MAX8925_ALARM1_MIN 0x11 48 #define MAX8925_ALARM1_HOUR 0x12 49 #define MAX8925_ALARM1_WEEKDAY 0x13 50 #define MAX8925_ALARM1_DATE 0x14 51 #define MAX8925_ALARM1_MON 0x15 52 #define MAX8925_ALARM1_YEAR1 0x16 53 #define MAX8925_ALARM1_YEAR2 0x17 54 #define MAX8925_RTC_CNTL 0x1b 55 #define MAX8925_RTC_STATUS 0x20 56 57 #define TIME_NUM 8 58 #define ALARM_1SEC (1 << 7) 59 #define HOUR_12 (1 << 7) 60 #define HOUR_AM_PM (1 << 5) 61 #define ALARM0_IRQ (1 << 3) 62 #define ALARM1_IRQ (1 << 2) 63 #define ALARM0_STATUS (1 << 2) 64 #define ALARM1_STATUS (1 << 1) 65 66 67 struct max8925_rtc_info { 68 struct rtc_device *rtc_dev; 69 struct max8925_chip *chip; 70 struct i2c_client *rtc; 71 struct device *dev; 72 }; 73 74 static irqreturn_t rtc_update_handler(int irq, void *data) 75 { 76 struct max8925_rtc_info *info = (struct max8925_rtc_info *)data; 77 78 /* disable ALARM0 except for 1SEC alarm */ 79 max8925_set_bits(info->rtc, MAX8925_ALARM0_CNTL, 0x7f, 0); 80 rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF); 81 return IRQ_HANDLED; 82 } 83 84 static int tm_calc(struct rtc_time *tm, unsigned char *buf, int len) 85 { 86 if (len < TIME_NUM) 87 return -EINVAL; 88 tm->tm_year = (buf[RTC_YEAR2] >> 4) * 1000 89 + (buf[RTC_YEAR2] & 0xf) * 100 90 + (buf[RTC_YEAR1] >> 4) * 10 91 + (buf[RTC_YEAR1] & 0xf); 92 tm->tm_year -= 1900; 93 tm->tm_mon = ((buf[RTC_MONTH] >> 4) & 0x01) * 10 94 + (buf[RTC_MONTH] & 0x0f); 95 tm->tm_mday = ((buf[RTC_DATE] >> 4) & 0x03) * 10 96 + (buf[RTC_DATE] & 0x0f); 97 tm->tm_wday = buf[RTC_WEEKDAY] & 0x07; 98 if (buf[RTC_HOUR] & HOUR_12) { 99 tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x1) * 10 100 + (buf[RTC_HOUR] & 0x0f); 101 if (buf[RTC_HOUR] & HOUR_AM_PM) 102 tm->tm_hour += 12; 103 } else 104 tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x03) * 10 105 + (buf[RTC_HOUR] & 0x0f); 106 tm->tm_min = ((buf[RTC_MIN] >> 4) & 0x7) * 10 107 + (buf[RTC_MIN] & 0x0f); 108 tm->tm_sec = ((buf[RTC_SEC] >> 4) & 0x7) * 10 109 + (buf[RTC_SEC] & 0x0f); 110 return 0; 111 } 112 113 static int data_calc(unsigned char *buf, struct rtc_time *tm, int len) 114 { 115 unsigned char high, low; 116 117 if (len < TIME_NUM) 118 return -EINVAL; 119 120 high = (tm->tm_year + 1900) / 1000; 121 low = (tm->tm_year + 1900) / 100; 122 low = low - high * 10; 123 buf[RTC_YEAR2] = (high << 4) + low; 124 high = (tm->tm_year + 1900) / 10; 125 low = tm->tm_year + 1900; 126 low = low - high * 10; 127 high = high - (high / 10) * 10; 128 buf[RTC_YEAR1] = (high << 4) + low; 129 high = tm->tm_mon / 10; 130 low = tm->tm_mon; 131 low = low - high * 10; 132 buf[RTC_MONTH] = (high << 4) + low; 133 high = tm->tm_mday / 10; 134 low = tm->tm_mday; 135 low = low - high * 10; 136 buf[RTC_DATE] = (high << 4) + low; 137 buf[RTC_WEEKDAY] = tm->tm_wday; 138 high = tm->tm_hour / 10; 139 low = tm->tm_hour; 140 low = low - high * 10; 141 buf[RTC_HOUR] = (high << 4) + low; 142 high = tm->tm_min / 10; 143 low = tm->tm_min; 144 low = low - high * 10; 145 buf[RTC_MIN] = (high << 4) + low; 146 high = tm->tm_sec / 10; 147 low = tm->tm_sec; 148 low = low - high * 10; 149 buf[RTC_SEC] = (high << 4) + low; 150 return 0; 151 } 152 153 static int max8925_rtc_read_time(struct device *dev, struct rtc_time *tm) 154 { 155 struct max8925_rtc_info *info = dev_get_drvdata(dev); 156 unsigned char buf[TIME_NUM]; 157 int ret; 158 159 ret = max8925_bulk_read(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf); 160 if (ret < 0) 161 goto out; 162 ret = tm_calc(tm, buf, TIME_NUM); 163 out: 164 return ret; 165 } 166 167 static int max8925_rtc_set_time(struct device *dev, struct rtc_time *tm) 168 { 169 struct max8925_rtc_info *info = dev_get_drvdata(dev); 170 unsigned char buf[TIME_NUM]; 171 int ret; 172 173 ret = data_calc(buf, tm, TIME_NUM); 174 if (ret < 0) 175 goto out; 176 ret = max8925_bulk_write(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf); 177 out: 178 return ret; 179 } 180 181 static int max8925_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 182 { 183 struct max8925_rtc_info *info = dev_get_drvdata(dev); 184 unsigned char buf[TIME_NUM]; 185 int ret; 186 187 ret = max8925_bulk_read(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf); 188 if (ret < 0) 189 goto out; 190 ret = tm_calc(&alrm->time, buf, TIME_NUM); 191 if (ret < 0) 192 goto out; 193 ret = max8925_reg_read(info->rtc, MAX8925_RTC_IRQ_MASK); 194 if (ret < 0) 195 goto out; 196 if ((ret & ALARM0_IRQ) == 0) 197 alrm->enabled = 1; 198 else 199 alrm->enabled = 0; 200 ret = max8925_reg_read(info->rtc, MAX8925_RTC_STATUS); 201 if (ret < 0) 202 goto out; 203 if (ret & ALARM0_STATUS) 204 alrm->pending = 1; 205 else 206 alrm->pending = 0; 207 out: 208 return ret; 209 } 210 211 static int max8925_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 212 { 213 struct max8925_rtc_info *info = dev_get_drvdata(dev); 214 unsigned char buf[TIME_NUM]; 215 int ret; 216 217 ret = data_calc(buf, &alrm->time, TIME_NUM); 218 if (ret < 0) 219 goto out; 220 ret = max8925_bulk_write(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf); 221 if (ret < 0) 222 goto out; 223 /* only enable alarm on year/month/day/hour/min/sec */ 224 ret = max8925_reg_write(info->rtc, MAX8925_ALARM0_CNTL, 0x77); 225 if (ret < 0) 226 goto out; 227 out: 228 return ret; 229 } 230 231 static const struct rtc_class_ops max8925_rtc_ops = { 232 .read_time = max8925_rtc_read_time, 233 .set_time = max8925_rtc_set_time, 234 .read_alarm = max8925_rtc_read_alarm, 235 .set_alarm = max8925_rtc_set_alarm, 236 }; 237 238 static int __devinit max8925_rtc_probe(struct platform_device *pdev) 239 { 240 struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent); 241 struct max8925_rtc_info *info; 242 int irq, ret; 243 244 info = kzalloc(sizeof(struct max8925_rtc_info), GFP_KERNEL); 245 if (!info) 246 return -ENOMEM; 247 info->chip = chip; 248 info->rtc = chip->rtc; 249 info->dev = &pdev->dev; 250 irq = chip->irq_base + MAX8925_IRQ_RTC_ALARM0; 251 252 ret = request_threaded_irq(irq, NULL, rtc_update_handler, 253 IRQF_ONESHOT, "rtc-alarm0", info); 254 if (ret < 0) { 255 dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n", 256 irq, ret); 257 goto out_irq; 258 } 259 260 info->rtc_dev = rtc_device_register("max8925-rtc", &pdev->dev, 261 &max8925_rtc_ops, THIS_MODULE); 262 ret = PTR_ERR(info->rtc_dev); 263 if (IS_ERR(info->rtc_dev)) { 264 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret); 265 goto out_rtc; 266 } 267 268 dev_set_drvdata(&pdev->dev, info); 269 platform_set_drvdata(pdev, info); 270 271 return 0; 272 out_rtc: 273 free_irq(chip->irq_base + MAX8925_IRQ_RTC_ALARM0, info); 274 out_irq: 275 kfree(info); 276 return ret; 277 } 278 279 static int __devexit max8925_rtc_remove(struct platform_device *pdev) 280 { 281 struct max8925_rtc_info *info = platform_get_drvdata(pdev); 282 283 if (info) { 284 free_irq(info->chip->irq_base + MAX8925_IRQ_RTC_ALARM0, info); 285 rtc_device_unregister(info->rtc_dev); 286 kfree(info); 287 } 288 return 0; 289 } 290 291 static struct platform_driver max8925_rtc_driver = { 292 .driver = { 293 .name = "max8925-rtc", 294 .owner = THIS_MODULE, 295 }, 296 .probe = max8925_rtc_probe, 297 .remove = __devexit_p(max8925_rtc_remove), 298 }; 299 300 static int __init max8925_rtc_init(void) 301 { 302 return platform_driver_register(&max8925_rtc_driver); 303 } 304 module_init(max8925_rtc_init); 305 306 static void __exit max8925_rtc_exit(void) 307 { 308 platform_driver_unregister(&max8925_rtc_driver); 309 } 310 module_exit(max8925_rtc_exit); 311 312 MODULE_DESCRIPTION("Maxim MAX8925 RTC driver"); 313 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>"); 314 MODULE_LICENSE("GPL"); 315 316