1 /* 2 * Real time clock driver for DA9052 3 * 4 * Copyright(c) 2012 Dialog Semiconductor Ltd. 5 * 6 * Author: Dajun Dajun Chen <dajun.chen@diasemi.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 */ 14 15 #include <linux/module.h> 16 #include <linux/platform_device.h> 17 #include <linux/rtc.h> 18 #include <linux/err.h> 19 #include <linux/delay.h> 20 21 #include <linux/mfd/da9052/da9052.h> 22 #include <linux/mfd/da9052/reg.h> 23 24 #define rtc_err(rtc, fmt, ...) \ 25 dev_err(rtc->da9052->dev, "%s: " fmt, __func__, ##__VA_ARGS__) 26 27 #define DA9052_GET_TIME_RETRIES 5 28 29 struct da9052_rtc { 30 struct rtc_device *rtc; 31 struct da9052 *da9052; 32 }; 33 34 static int da9052_rtc_enable_alarm(struct da9052_rtc *rtc, bool enable) 35 { 36 int ret; 37 if (enable) { 38 ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG, 39 DA9052_ALARM_Y_ALARM_ON|DA9052_ALARM_Y_TICK_ON, 40 DA9052_ALARM_Y_ALARM_ON); 41 if (ret != 0) 42 rtc_err(rtc, "Failed to enable ALM: %d\n", ret); 43 } else { 44 ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG, 45 DA9052_ALARM_Y_ALARM_ON|DA9052_ALARM_Y_TICK_ON, 0); 46 if (ret != 0) 47 rtc_err(rtc, "Write error: %d\n", ret); 48 } 49 return ret; 50 } 51 52 static irqreturn_t da9052_rtc_irq(int irq, void *data) 53 { 54 struct da9052_rtc *rtc = data; 55 56 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF); 57 58 return IRQ_HANDLED; 59 } 60 61 static int da9052_read_alarm(struct da9052_rtc *rtc, struct rtc_time *rtc_tm) 62 { 63 int ret; 64 uint8_t v[2][5]; 65 int idx = 1; 66 int timeout = DA9052_GET_TIME_RETRIES; 67 68 ret = da9052_group_read(rtc->da9052, DA9052_ALARM_MI_REG, 5, &v[0][0]); 69 if (ret) { 70 rtc_err(rtc, "Failed to group read ALM: %d\n", ret); 71 return ret; 72 } 73 74 do { 75 ret = da9052_group_read(rtc->da9052, 76 DA9052_ALARM_MI_REG, 5, &v[idx][0]); 77 if (ret) { 78 rtc_err(rtc, "Failed to group read ALM: %d\n", ret); 79 return ret; 80 } 81 82 if (memcmp(&v[0][0], &v[1][0], 5) == 0) { 83 rtc_tm->tm_year = (v[0][4] & DA9052_RTC_YEAR) + 100; 84 rtc_tm->tm_mon = (v[0][3] & DA9052_RTC_MONTH) - 1; 85 rtc_tm->tm_mday = v[0][2] & DA9052_RTC_DAY; 86 rtc_tm->tm_hour = v[0][1] & DA9052_RTC_HOUR; 87 rtc_tm->tm_min = v[0][0] & DA9052_RTC_MIN; 88 89 ret = rtc_valid_tm(rtc_tm); 90 return ret; 91 } 92 93 idx = (1-idx); 94 msleep(20); 95 96 } while (timeout--); 97 98 rtc_err(rtc, "Timed out reading alarm time\n"); 99 100 return -EIO; 101 } 102 103 static int da9052_set_alarm(struct da9052_rtc *rtc, struct rtc_time *rtc_tm) 104 { 105 struct da9052 *da9052 = rtc->da9052; 106 unsigned long alm_time; 107 int ret; 108 uint8_t v[3]; 109 110 ret = rtc_tm_to_time(rtc_tm, &alm_time); 111 if (ret != 0) 112 return ret; 113 114 if (rtc_tm->tm_sec > 0) { 115 alm_time += 60 - rtc_tm->tm_sec; 116 rtc_time_to_tm(alm_time, rtc_tm); 117 } 118 BUG_ON(rtc_tm->tm_sec); /* it will cause repeated irqs if not zero */ 119 120 rtc_tm->tm_year -= 100; 121 rtc_tm->tm_mon += 1; 122 123 ret = da9052_reg_update(da9052, DA9052_ALARM_MI_REG, 124 DA9052_RTC_MIN, rtc_tm->tm_min); 125 if (ret != 0) { 126 rtc_err(rtc, "Failed to write ALRM MIN: %d\n", ret); 127 return ret; 128 } 129 130 v[0] = rtc_tm->tm_hour; 131 v[1] = rtc_tm->tm_mday; 132 v[2] = rtc_tm->tm_mon; 133 134 ret = da9052_group_write(da9052, DA9052_ALARM_H_REG, 3, v); 135 if (ret < 0) 136 return ret; 137 138 ret = da9052_reg_update(da9052, DA9052_ALARM_Y_REG, 139 DA9052_RTC_YEAR, rtc_tm->tm_year); 140 if (ret != 0) 141 rtc_err(rtc, "Failed to write ALRM YEAR: %d\n", ret); 142 143 return ret; 144 } 145 146 static int da9052_rtc_get_alarm_status(struct da9052_rtc *rtc) 147 { 148 int ret; 149 150 ret = da9052_reg_read(rtc->da9052, DA9052_ALARM_Y_REG); 151 if (ret < 0) { 152 rtc_err(rtc, "Failed to read ALM: %d\n", ret); 153 return ret; 154 } 155 156 return !!(ret&DA9052_ALARM_Y_ALARM_ON); 157 } 158 159 static int da9052_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm) 160 { 161 struct da9052_rtc *rtc = dev_get_drvdata(dev); 162 int ret; 163 uint8_t v[2][6]; 164 int idx = 1; 165 int timeout = DA9052_GET_TIME_RETRIES; 166 167 ret = da9052_group_read(rtc->da9052, DA9052_COUNT_S_REG, 6, &v[0][0]); 168 if (ret) { 169 rtc_err(rtc, "Failed to read RTC time : %d\n", ret); 170 return ret; 171 } 172 173 do { 174 ret = da9052_group_read(rtc->da9052, 175 DA9052_COUNT_S_REG, 6, &v[idx][0]); 176 if (ret) { 177 rtc_err(rtc, "Failed to read RTC time : %d\n", ret); 178 return ret; 179 } 180 181 if (memcmp(&v[0][0], &v[1][0], 6) == 0) { 182 rtc_tm->tm_year = (v[0][5] & DA9052_RTC_YEAR) + 100; 183 rtc_tm->tm_mon = (v[0][4] & DA9052_RTC_MONTH) - 1; 184 rtc_tm->tm_mday = v[0][3] & DA9052_RTC_DAY; 185 rtc_tm->tm_hour = v[0][2] & DA9052_RTC_HOUR; 186 rtc_tm->tm_min = v[0][1] & DA9052_RTC_MIN; 187 rtc_tm->tm_sec = v[0][0] & DA9052_RTC_SEC; 188 189 ret = rtc_valid_tm(rtc_tm); 190 return ret; 191 } 192 193 idx = (1-idx); 194 msleep(20); 195 196 } while (timeout--); 197 198 rtc_err(rtc, "Timed out reading time\n"); 199 200 return -EIO; 201 } 202 203 static int da9052_rtc_set_time(struct device *dev, struct rtc_time *tm) 204 { 205 struct da9052_rtc *rtc; 206 uint8_t v[6]; 207 int ret; 208 209 /* DA9052 only has 6 bits for year - to represent 2000-2063 */ 210 if ((tm->tm_year < 100) || (tm->tm_year > 163)) 211 return -EINVAL; 212 213 rtc = dev_get_drvdata(dev); 214 215 v[0] = tm->tm_sec; 216 v[1] = tm->tm_min; 217 v[2] = tm->tm_hour; 218 v[3] = tm->tm_mday; 219 v[4] = tm->tm_mon + 1; 220 v[5] = tm->tm_year - 100; 221 222 ret = da9052_group_write(rtc->da9052, DA9052_COUNT_S_REG, 6, v); 223 if (ret < 0) 224 rtc_err(rtc, "failed to set RTC time: %d\n", ret); 225 return ret; 226 } 227 228 static int da9052_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 229 { 230 int ret; 231 struct rtc_time *tm = &alrm->time; 232 struct da9052_rtc *rtc = dev_get_drvdata(dev); 233 234 ret = da9052_read_alarm(rtc, tm); 235 if (ret < 0) { 236 rtc_err(rtc, "failed to read RTC alarm: %d\n", ret); 237 return ret; 238 } 239 240 alrm->enabled = da9052_rtc_get_alarm_status(rtc); 241 return 0; 242 } 243 244 static int da9052_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 245 { 246 int ret; 247 struct rtc_time *tm = &alrm->time; 248 struct da9052_rtc *rtc = dev_get_drvdata(dev); 249 250 /* DA9052 only has 6 bits for year - to represent 2000-2063 */ 251 if ((tm->tm_year < 100) || (tm->tm_year > 163)) 252 return -EINVAL; 253 254 ret = da9052_rtc_enable_alarm(rtc, 0); 255 if (ret < 0) 256 return ret; 257 258 ret = da9052_set_alarm(rtc, tm); 259 if (ret < 0) 260 return ret; 261 262 ret = da9052_rtc_enable_alarm(rtc, 1); 263 return ret; 264 } 265 266 static int da9052_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) 267 { 268 struct da9052_rtc *rtc = dev_get_drvdata(dev); 269 270 return da9052_rtc_enable_alarm(rtc, enabled); 271 } 272 273 static const struct rtc_class_ops da9052_rtc_ops = { 274 .read_time = da9052_rtc_read_time, 275 .set_time = da9052_rtc_set_time, 276 .read_alarm = da9052_rtc_read_alarm, 277 .set_alarm = da9052_rtc_set_alarm, 278 .alarm_irq_enable = da9052_rtc_alarm_irq_enable, 279 }; 280 281 static int da9052_rtc_probe(struct platform_device *pdev) 282 { 283 struct da9052_rtc *rtc; 284 int ret; 285 286 rtc = devm_kzalloc(&pdev->dev, sizeof(struct da9052_rtc), GFP_KERNEL); 287 if (!rtc) 288 return -ENOMEM; 289 290 rtc->da9052 = dev_get_drvdata(pdev->dev.parent); 291 platform_set_drvdata(pdev, rtc); 292 293 ret = da9052_reg_write(rtc->da9052, DA9052_BBAT_CONT_REG, 0xFE); 294 if (ret < 0) { 295 rtc_err(rtc, 296 "Failed to setup RTC battery charging: %d\n", ret); 297 return ret; 298 } 299 300 ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG, 301 DA9052_ALARM_Y_TICK_ON, 0); 302 if (ret != 0) 303 rtc_err(rtc, "Failed to disable TICKS: %d\n", ret); 304 305 ret = da9052_request_irq(rtc->da9052, DA9052_IRQ_ALARM, "ALM", 306 da9052_rtc_irq, rtc); 307 if (ret != 0) { 308 rtc_err(rtc, "irq registration failed: %d\n", ret); 309 return ret; 310 } 311 312 device_init_wakeup(&pdev->dev, true); 313 314 rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, 315 &da9052_rtc_ops, THIS_MODULE); 316 return PTR_ERR_OR_ZERO(rtc->rtc); 317 } 318 319 static struct platform_driver da9052_rtc_driver = { 320 .probe = da9052_rtc_probe, 321 .driver = { 322 .name = "da9052-rtc", 323 }, 324 }; 325 326 module_platform_driver(da9052_rtc_driver); 327 328 MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>"); 329 MODULE_DESCRIPTION("RTC driver for Dialog DA9052 PMIC"); 330 MODULE_LICENSE("GPL"); 331 MODULE_ALIAS("platform:da9052-rtc"); 332