1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Real time clock driver for DA9052 4 * 5 * Copyright(c) 2012 Dialog Semiconductor Ltd. 6 * 7 * Author: Dajun Dajun Chen <dajun.chen@diasemi.com> 8 */ 9 10 #include <linux/module.h> 11 #include <linux/platform_device.h> 12 #include <linux/rtc.h> 13 #include <linux/err.h> 14 #include <linux/delay.h> 15 16 #include <linux/mfd/da9052/da9052.h> 17 #include <linux/mfd/da9052/reg.h> 18 19 #define rtc_err(rtc, fmt, ...) \ 20 dev_err(rtc->da9052->dev, "%s: " fmt, __func__, ##__VA_ARGS__) 21 22 #define DA9052_GET_TIME_RETRIES 5 23 24 struct da9052_rtc { 25 struct rtc_device *rtc; 26 struct da9052 *da9052; 27 }; 28 29 static int da9052_rtc_enable_alarm(struct da9052_rtc *rtc, bool enable) 30 { 31 int ret; 32 if (enable) { 33 ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG, 34 DA9052_ALARM_Y_ALARM_ON|DA9052_ALARM_Y_TICK_ON, 35 DA9052_ALARM_Y_ALARM_ON); 36 if (ret != 0) 37 rtc_err(rtc, "Failed to enable ALM: %d\n", ret); 38 } else { 39 ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG, 40 DA9052_ALARM_Y_ALARM_ON|DA9052_ALARM_Y_TICK_ON, 0); 41 if (ret != 0) 42 rtc_err(rtc, "Write error: %d\n", ret); 43 } 44 return ret; 45 } 46 47 static irqreturn_t da9052_rtc_irq(int irq, void *data) 48 { 49 struct da9052_rtc *rtc = data; 50 51 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF); 52 53 return IRQ_HANDLED; 54 } 55 56 static int da9052_read_alarm(struct da9052_rtc *rtc, struct rtc_time *rtc_tm) 57 { 58 int ret; 59 uint8_t v[2][5]; 60 int idx = 1; 61 int timeout = DA9052_GET_TIME_RETRIES; 62 63 ret = da9052_group_read(rtc->da9052, DA9052_ALARM_MI_REG, 5, &v[0][0]); 64 if (ret) { 65 rtc_err(rtc, "Failed to group read ALM: %d\n", ret); 66 return ret; 67 } 68 69 do { 70 ret = da9052_group_read(rtc->da9052, 71 DA9052_ALARM_MI_REG, 5, &v[idx][0]); 72 if (ret) { 73 rtc_err(rtc, "Failed to group read ALM: %d\n", ret); 74 return ret; 75 } 76 77 if (memcmp(&v[0][0], &v[1][0], 5) == 0) { 78 rtc_tm->tm_year = (v[0][4] & DA9052_RTC_YEAR) + 100; 79 rtc_tm->tm_mon = (v[0][3] & DA9052_RTC_MONTH) - 1; 80 rtc_tm->tm_mday = v[0][2] & DA9052_RTC_DAY; 81 rtc_tm->tm_hour = v[0][1] & DA9052_RTC_HOUR; 82 rtc_tm->tm_min = v[0][0] & DA9052_RTC_MIN; 83 rtc_tm->tm_sec = 0; 84 85 ret = rtc_valid_tm(rtc_tm); 86 return ret; 87 } 88 89 idx = (1-idx); 90 msleep(20); 91 92 } while (timeout--); 93 94 rtc_err(rtc, "Timed out reading alarm time\n"); 95 96 return -EIO; 97 } 98 99 static int da9052_set_alarm(struct da9052_rtc *rtc, struct rtc_time *rtc_tm) 100 { 101 struct da9052 *da9052 = rtc->da9052; 102 unsigned long alm_time; 103 int ret; 104 uint8_t v[3]; 105 106 ret = rtc_tm_to_time(rtc_tm, &alm_time); 107 if (ret != 0) 108 return ret; 109 110 if (rtc_tm->tm_sec > 0) { 111 alm_time += 60 - rtc_tm->tm_sec; 112 rtc_time_to_tm(alm_time, rtc_tm); 113 } 114 BUG_ON(rtc_tm->tm_sec); /* it will cause repeated irqs if not zero */ 115 116 rtc_tm->tm_year -= 100; 117 rtc_tm->tm_mon += 1; 118 119 ret = da9052_reg_update(da9052, DA9052_ALARM_MI_REG, 120 DA9052_RTC_MIN, rtc_tm->tm_min); 121 if (ret != 0) { 122 rtc_err(rtc, "Failed to write ALRM MIN: %d\n", ret); 123 return ret; 124 } 125 126 v[0] = rtc_tm->tm_hour; 127 v[1] = rtc_tm->tm_mday; 128 v[2] = rtc_tm->tm_mon; 129 130 ret = da9052_group_write(da9052, DA9052_ALARM_H_REG, 3, v); 131 if (ret < 0) 132 return ret; 133 134 ret = da9052_reg_update(da9052, DA9052_ALARM_Y_REG, 135 DA9052_RTC_YEAR, rtc_tm->tm_year); 136 if (ret != 0) 137 rtc_err(rtc, "Failed to write ALRM YEAR: %d\n", ret); 138 139 return ret; 140 } 141 142 static int da9052_rtc_get_alarm_status(struct da9052_rtc *rtc) 143 { 144 int ret; 145 146 ret = da9052_reg_read(rtc->da9052, DA9052_ALARM_Y_REG); 147 if (ret < 0) { 148 rtc_err(rtc, "Failed to read ALM: %d\n", ret); 149 return ret; 150 } 151 152 return !!(ret&DA9052_ALARM_Y_ALARM_ON); 153 } 154 155 static int da9052_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm) 156 { 157 struct da9052_rtc *rtc = dev_get_drvdata(dev); 158 int ret; 159 uint8_t v[2][6]; 160 int idx = 1; 161 int timeout = DA9052_GET_TIME_RETRIES; 162 163 ret = da9052_group_read(rtc->da9052, DA9052_COUNT_S_REG, 6, &v[0][0]); 164 if (ret) { 165 rtc_err(rtc, "Failed to read RTC time : %d\n", ret); 166 return ret; 167 } 168 169 do { 170 ret = da9052_group_read(rtc->da9052, 171 DA9052_COUNT_S_REG, 6, &v[idx][0]); 172 if (ret) { 173 rtc_err(rtc, "Failed to read RTC time : %d\n", ret); 174 return ret; 175 } 176 177 if (memcmp(&v[0][0], &v[1][0], 6) == 0) { 178 rtc_tm->tm_year = (v[0][5] & DA9052_RTC_YEAR) + 100; 179 rtc_tm->tm_mon = (v[0][4] & DA9052_RTC_MONTH) - 1; 180 rtc_tm->tm_mday = v[0][3] & DA9052_RTC_DAY; 181 rtc_tm->tm_hour = v[0][2] & DA9052_RTC_HOUR; 182 rtc_tm->tm_min = v[0][1] & DA9052_RTC_MIN; 183 rtc_tm->tm_sec = v[0][0] & DA9052_RTC_SEC; 184 185 return 0; 186 } 187 188 idx = (1-idx); 189 msleep(20); 190 191 } while (timeout--); 192 193 rtc_err(rtc, "Timed out reading time\n"); 194 195 return -EIO; 196 } 197 198 static int da9052_rtc_set_time(struct device *dev, struct rtc_time *tm) 199 { 200 struct da9052_rtc *rtc; 201 uint8_t v[6]; 202 int ret; 203 204 /* DA9052 only has 6 bits for year - to represent 2000-2063 */ 205 if ((tm->tm_year < 100) || (tm->tm_year > 163)) 206 return -EINVAL; 207 208 rtc = dev_get_drvdata(dev); 209 210 v[0] = tm->tm_sec; 211 v[1] = tm->tm_min; 212 v[2] = tm->tm_hour; 213 v[3] = tm->tm_mday; 214 v[4] = tm->tm_mon + 1; 215 v[5] = tm->tm_year - 100; 216 217 ret = da9052_group_write(rtc->da9052, DA9052_COUNT_S_REG, 6, v); 218 if (ret < 0) 219 rtc_err(rtc, "failed to set RTC time: %d\n", ret); 220 return ret; 221 } 222 223 static int da9052_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 224 { 225 int ret; 226 struct rtc_time *tm = &alrm->time; 227 struct da9052_rtc *rtc = dev_get_drvdata(dev); 228 229 ret = da9052_read_alarm(rtc, tm); 230 if (ret < 0) { 231 rtc_err(rtc, "failed to read RTC alarm: %d\n", ret); 232 return ret; 233 } 234 235 alrm->enabled = da9052_rtc_get_alarm_status(rtc); 236 return 0; 237 } 238 239 static int da9052_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 240 { 241 int ret; 242 struct rtc_time *tm = &alrm->time; 243 struct da9052_rtc *rtc = dev_get_drvdata(dev); 244 245 /* DA9052 only has 6 bits for year - to represent 2000-2063 */ 246 if ((tm->tm_year < 100) || (tm->tm_year > 163)) 247 return -EINVAL; 248 249 ret = da9052_rtc_enable_alarm(rtc, 0); 250 if (ret < 0) 251 return ret; 252 253 ret = da9052_set_alarm(rtc, tm); 254 if (ret < 0) 255 return ret; 256 257 ret = da9052_rtc_enable_alarm(rtc, 1); 258 return ret; 259 } 260 261 static int da9052_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) 262 { 263 struct da9052_rtc *rtc = dev_get_drvdata(dev); 264 265 return da9052_rtc_enable_alarm(rtc, enabled); 266 } 267 268 static const struct rtc_class_ops da9052_rtc_ops = { 269 .read_time = da9052_rtc_read_time, 270 .set_time = da9052_rtc_set_time, 271 .read_alarm = da9052_rtc_read_alarm, 272 .set_alarm = da9052_rtc_set_alarm, 273 .alarm_irq_enable = da9052_rtc_alarm_irq_enable, 274 }; 275 276 static int da9052_rtc_probe(struct platform_device *pdev) 277 { 278 struct da9052_rtc *rtc; 279 int ret; 280 281 rtc = devm_kzalloc(&pdev->dev, sizeof(struct da9052_rtc), GFP_KERNEL); 282 if (!rtc) 283 return -ENOMEM; 284 285 rtc->da9052 = dev_get_drvdata(pdev->dev.parent); 286 platform_set_drvdata(pdev, rtc); 287 288 ret = da9052_reg_write(rtc->da9052, DA9052_BBAT_CONT_REG, 0xFE); 289 if (ret < 0) { 290 rtc_err(rtc, 291 "Failed to setup RTC battery charging: %d\n", ret); 292 return ret; 293 } 294 295 ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG, 296 DA9052_ALARM_Y_TICK_ON, 0); 297 if (ret != 0) 298 rtc_err(rtc, "Failed to disable TICKS: %d\n", ret); 299 300 device_init_wakeup(&pdev->dev, true); 301 rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, 302 &da9052_rtc_ops, THIS_MODULE); 303 304 if (IS_ERR(rtc->rtc)) 305 return PTR_ERR(rtc->rtc); 306 307 ret = da9052_request_irq(rtc->da9052, DA9052_IRQ_ALARM, "ALM", 308 da9052_rtc_irq, rtc); 309 if (ret != 0) { 310 rtc_err(rtc, "irq registration failed: %d\n", ret); 311 return ret; 312 } 313 314 return 0; 315 } 316 317 static struct platform_driver da9052_rtc_driver = { 318 .probe = da9052_rtc_probe, 319 .driver = { 320 .name = "da9052-rtc", 321 }, 322 }; 323 324 module_platform_driver(da9052_rtc_driver); 325 326 MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>"); 327 MODULE_DESCRIPTION("RTC driver for Dialog DA9052 PMIC"); 328 MODULE_LICENSE("GPL"); 329 MODULE_ALIAS("platform:da9052-rtc"); 330