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 rtc_tm->tm_sec = 0; 89 90 ret = rtc_valid_tm(rtc_tm); 91 return ret; 92 } 93 94 idx = (1-idx); 95 msleep(20); 96 97 } while (timeout--); 98 99 rtc_err(rtc, "Timed out reading alarm time\n"); 100 101 return -EIO; 102 } 103 104 static int da9052_set_alarm(struct da9052_rtc *rtc, struct rtc_time *rtc_tm) 105 { 106 struct da9052 *da9052 = rtc->da9052; 107 unsigned long alm_time; 108 int ret; 109 uint8_t v[3]; 110 111 ret = rtc_tm_to_time(rtc_tm, &alm_time); 112 if (ret != 0) 113 return ret; 114 115 if (rtc_tm->tm_sec > 0) { 116 alm_time += 60 - rtc_tm->tm_sec; 117 rtc_time_to_tm(alm_time, rtc_tm); 118 } 119 BUG_ON(rtc_tm->tm_sec); /* it will cause repeated irqs if not zero */ 120 121 rtc_tm->tm_year -= 100; 122 rtc_tm->tm_mon += 1; 123 124 ret = da9052_reg_update(da9052, DA9052_ALARM_MI_REG, 125 DA9052_RTC_MIN, rtc_tm->tm_min); 126 if (ret != 0) { 127 rtc_err(rtc, "Failed to write ALRM MIN: %d\n", ret); 128 return ret; 129 } 130 131 v[0] = rtc_tm->tm_hour; 132 v[1] = rtc_tm->tm_mday; 133 v[2] = rtc_tm->tm_mon; 134 135 ret = da9052_group_write(da9052, DA9052_ALARM_H_REG, 3, v); 136 if (ret < 0) 137 return ret; 138 139 ret = da9052_reg_update(da9052, DA9052_ALARM_Y_REG, 140 DA9052_RTC_YEAR, rtc_tm->tm_year); 141 if (ret != 0) 142 rtc_err(rtc, "Failed to write ALRM YEAR: %d\n", ret); 143 144 return ret; 145 } 146 147 static int da9052_rtc_get_alarm_status(struct da9052_rtc *rtc) 148 { 149 int ret; 150 151 ret = da9052_reg_read(rtc->da9052, DA9052_ALARM_Y_REG); 152 if (ret < 0) { 153 rtc_err(rtc, "Failed to read ALM: %d\n", ret); 154 return ret; 155 } 156 157 return !!(ret&DA9052_ALARM_Y_ALARM_ON); 158 } 159 160 static int da9052_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm) 161 { 162 struct da9052_rtc *rtc = dev_get_drvdata(dev); 163 int ret; 164 uint8_t v[2][6]; 165 int idx = 1; 166 int timeout = DA9052_GET_TIME_RETRIES; 167 168 ret = da9052_group_read(rtc->da9052, DA9052_COUNT_S_REG, 6, &v[0][0]); 169 if (ret) { 170 rtc_err(rtc, "Failed to read RTC time : %d\n", ret); 171 return ret; 172 } 173 174 do { 175 ret = da9052_group_read(rtc->da9052, 176 DA9052_COUNT_S_REG, 6, &v[idx][0]); 177 if (ret) { 178 rtc_err(rtc, "Failed to read RTC time : %d\n", ret); 179 return ret; 180 } 181 182 if (memcmp(&v[0][0], &v[1][0], 6) == 0) { 183 rtc_tm->tm_year = (v[0][5] & DA9052_RTC_YEAR) + 100; 184 rtc_tm->tm_mon = (v[0][4] & DA9052_RTC_MONTH) - 1; 185 rtc_tm->tm_mday = v[0][3] & DA9052_RTC_DAY; 186 rtc_tm->tm_hour = v[0][2] & DA9052_RTC_HOUR; 187 rtc_tm->tm_min = v[0][1] & DA9052_RTC_MIN; 188 rtc_tm->tm_sec = v[0][0] & DA9052_RTC_SEC; 189 190 ret = rtc_valid_tm(rtc_tm); 191 return ret; 192 } 193 194 idx = (1-idx); 195 msleep(20); 196 197 } while (timeout--); 198 199 rtc_err(rtc, "Timed out reading time\n"); 200 201 return -EIO; 202 } 203 204 static int da9052_rtc_set_time(struct device *dev, struct rtc_time *tm) 205 { 206 struct da9052_rtc *rtc; 207 uint8_t v[6]; 208 int ret; 209 210 /* DA9052 only has 6 bits for year - to represent 2000-2063 */ 211 if ((tm->tm_year < 100) || (tm->tm_year > 163)) 212 return -EINVAL; 213 214 rtc = dev_get_drvdata(dev); 215 216 v[0] = tm->tm_sec; 217 v[1] = tm->tm_min; 218 v[2] = tm->tm_hour; 219 v[3] = tm->tm_mday; 220 v[4] = tm->tm_mon + 1; 221 v[5] = tm->tm_year - 100; 222 223 ret = da9052_group_write(rtc->da9052, DA9052_COUNT_S_REG, 6, v); 224 if (ret < 0) 225 rtc_err(rtc, "failed to set RTC time: %d\n", ret); 226 return ret; 227 } 228 229 static int da9052_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 230 { 231 int ret; 232 struct rtc_time *tm = &alrm->time; 233 struct da9052_rtc *rtc = dev_get_drvdata(dev); 234 235 ret = da9052_read_alarm(rtc, tm); 236 if (ret < 0) { 237 rtc_err(rtc, "failed to read RTC alarm: %d\n", ret); 238 return ret; 239 } 240 241 alrm->enabled = da9052_rtc_get_alarm_status(rtc); 242 return 0; 243 } 244 245 static int da9052_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 246 { 247 int ret; 248 struct rtc_time *tm = &alrm->time; 249 struct da9052_rtc *rtc = dev_get_drvdata(dev); 250 251 /* DA9052 only has 6 bits for year - to represent 2000-2063 */ 252 if ((tm->tm_year < 100) || (tm->tm_year > 163)) 253 return -EINVAL; 254 255 ret = da9052_rtc_enable_alarm(rtc, 0); 256 if (ret < 0) 257 return ret; 258 259 ret = da9052_set_alarm(rtc, tm); 260 if (ret < 0) 261 return ret; 262 263 ret = da9052_rtc_enable_alarm(rtc, 1); 264 return ret; 265 } 266 267 static int da9052_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) 268 { 269 struct da9052_rtc *rtc = dev_get_drvdata(dev); 270 271 return da9052_rtc_enable_alarm(rtc, enabled); 272 } 273 274 static const struct rtc_class_ops da9052_rtc_ops = { 275 .read_time = da9052_rtc_read_time, 276 .set_time = da9052_rtc_set_time, 277 .read_alarm = da9052_rtc_read_alarm, 278 .set_alarm = da9052_rtc_set_alarm, 279 .alarm_irq_enable = da9052_rtc_alarm_irq_enable, 280 }; 281 282 static int da9052_rtc_probe(struct platform_device *pdev) 283 { 284 struct da9052_rtc *rtc; 285 int ret; 286 287 rtc = devm_kzalloc(&pdev->dev, sizeof(struct da9052_rtc), GFP_KERNEL); 288 if (!rtc) 289 return -ENOMEM; 290 291 rtc->da9052 = dev_get_drvdata(pdev->dev.parent); 292 platform_set_drvdata(pdev, rtc); 293 294 ret = da9052_reg_write(rtc->da9052, DA9052_BBAT_CONT_REG, 0xFE); 295 if (ret < 0) { 296 rtc_err(rtc, 297 "Failed to setup RTC battery charging: %d\n", ret); 298 return ret; 299 } 300 301 ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG, 302 DA9052_ALARM_Y_TICK_ON, 0); 303 if (ret != 0) 304 rtc_err(rtc, "Failed to disable TICKS: %d\n", ret); 305 306 device_init_wakeup(&pdev->dev, true); 307 rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, 308 &da9052_rtc_ops, THIS_MODULE); 309 310 if (IS_ERR(rtc->rtc)) 311 return PTR_ERR(rtc->rtc); 312 313 ret = da9052_request_irq(rtc->da9052, DA9052_IRQ_ALARM, "ALM", 314 da9052_rtc_irq, rtc); 315 if (ret != 0) { 316 rtc_err(rtc, "irq registration failed: %d\n", ret); 317 return ret; 318 } 319 320 return 0; 321 } 322 323 static struct platform_driver da9052_rtc_driver = { 324 .probe = da9052_rtc_probe, 325 .driver = { 326 .name = "da9052-rtc", 327 }, 328 }; 329 330 module_platform_driver(da9052_rtc_driver); 331 332 MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>"); 333 MODULE_DESCRIPTION("RTC driver for Dialog DA9052 PMIC"); 334 MODULE_LICENSE("GPL"); 335 MODULE_ALIAS("platform:da9052-rtc"); 336