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 alm_time = rtc_tm_to_time64(rtc_tm); 107 108 if (rtc_tm->tm_sec > 0) { 109 alm_time += 60 - rtc_tm->tm_sec; 110 rtc_time64_to_tm(alm_time, rtc_tm); 111 } 112 BUG_ON(rtc_tm->tm_sec); /* it will cause repeated irqs if not zero */ 113 114 rtc_tm->tm_year -= 100; 115 rtc_tm->tm_mon += 1; 116 117 ret = da9052_reg_update(da9052, DA9052_ALARM_MI_REG, 118 DA9052_RTC_MIN, rtc_tm->tm_min); 119 if (ret != 0) { 120 rtc_err(rtc, "Failed to write ALRM MIN: %d\n", ret); 121 return ret; 122 } 123 124 v[0] = rtc_tm->tm_hour; 125 v[1] = rtc_tm->tm_mday; 126 v[2] = rtc_tm->tm_mon; 127 128 ret = da9052_group_write(da9052, DA9052_ALARM_H_REG, 3, v); 129 if (ret < 0) 130 return ret; 131 132 ret = da9052_reg_update(da9052, DA9052_ALARM_Y_REG, 133 DA9052_RTC_YEAR, rtc_tm->tm_year); 134 if (ret != 0) 135 rtc_err(rtc, "Failed to write ALRM YEAR: %d\n", ret); 136 137 return ret; 138 } 139 140 static int da9052_rtc_get_alarm_status(struct da9052_rtc *rtc) 141 { 142 int ret; 143 144 ret = da9052_reg_read(rtc->da9052, DA9052_ALARM_Y_REG); 145 if (ret < 0) { 146 rtc_err(rtc, "Failed to read ALM: %d\n", ret); 147 return ret; 148 } 149 150 return !!(ret&DA9052_ALARM_Y_ALARM_ON); 151 } 152 153 static int da9052_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm) 154 { 155 struct da9052_rtc *rtc = dev_get_drvdata(dev); 156 int ret; 157 uint8_t v[2][6]; 158 int idx = 1; 159 int timeout = DA9052_GET_TIME_RETRIES; 160 161 ret = da9052_group_read(rtc->da9052, DA9052_COUNT_S_REG, 6, &v[0][0]); 162 if (ret) { 163 rtc_err(rtc, "Failed to read RTC time : %d\n", ret); 164 return ret; 165 } 166 167 do { 168 ret = da9052_group_read(rtc->da9052, 169 DA9052_COUNT_S_REG, 6, &v[idx][0]); 170 if (ret) { 171 rtc_err(rtc, "Failed to read RTC time : %d\n", ret); 172 return ret; 173 } 174 175 if (memcmp(&v[0][0], &v[1][0], 6) == 0) { 176 rtc_tm->tm_year = (v[0][5] & DA9052_RTC_YEAR) + 100; 177 rtc_tm->tm_mon = (v[0][4] & DA9052_RTC_MONTH) - 1; 178 rtc_tm->tm_mday = v[0][3] & DA9052_RTC_DAY; 179 rtc_tm->tm_hour = v[0][2] & DA9052_RTC_HOUR; 180 rtc_tm->tm_min = v[0][1] & DA9052_RTC_MIN; 181 rtc_tm->tm_sec = v[0][0] & DA9052_RTC_SEC; 182 183 return 0; 184 } 185 186 idx = (1-idx); 187 msleep(20); 188 189 } while (timeout--); 190 191 rtc_err(rtc, "Timed out reading time\n"); 192 193 return -EIO; 194 } 195 196 static int da9052_rtc_set_time(struct device *dev, struct rtc_time *tm) 197 { 198 struct da9052_rtc *rtc; 199 uint8_t v[6]; 200 int ret; 201 202 /* DA9052 only has 6 bits for year - to represent 2000-2063 */ 203 if ((tm->tm_year < 100) || (tm->tm_year > 163)) 204 return -EINVAL; 205 206 rtc = dev_get_drvdata(dev); 207 208 v[0] = tm->tm_sec; 209 v[1] = tm->tm_min; 210 v[2] = tm->tm_hour; 211 v[3] = tm->tm_mday; 212 v[4] = tm->tm_mon + 1; 213 v[5] = tm->tm_year - 100; 214 215 ret = da9052_group_write(rtc->da9052, DA9052_COUNT_S_REG, 6, v); 216 if (ret < 0) 217 rtc_err(rtc, "failed to set RTC time: %d\n", ret); 218 return ret; 219 } 220 221 static int da9052_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 222 { 223 int ret; 224 struct rtc_time *tm = &alrm->time; 225 struct da9052_rtc *rtc = dev_get_drvdata(dev); 226 227 ret = da9052_read_alarm(rtc, tm); 228 if (ret < 0) { 229 rtc_err(rtc, "failed to read RTC alarm: %d\n", ret); 230 return ret; 231 } 232 233 alrm->enabled = da9052_rtc_get_alarm_status(rtc); 234 return 0; 235 } 236 237 static int da9052_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 238 { 239 int ret; 240 struct rtc_time *tm = &alrm->time; 241 struct da9052_rtc *rtc = dev_get_drvdata(dev); 242 243 /* DA9052 only has 6 bits for year - to represent 2000-2063 */ 244 if ((tm->tm_year < 100) || (tm->tm_year > 163)) 245 return -EINVAL; 246 247 ret = da9052_rtc_enable_alarm(rtc, 0); 248 if (ret < 0) 249 return ret; 250 251 ret = da9052_set_alarm(rtc, tm); 252 if (ret < 0) 253 return ret; 254 255 ret = da9052_rtc_enable_alarm(rtc, 1); 256 return ret; 257 } 258 259 static int da9052_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) 260 { 261 struct da9052_rtc *rtc = dev_get_drvdata(dev); 262 263 return da9052_rtc_enable_alarm(rtc, enabled); 264 } 265 266 static const struct rtc_class_ops da9052_rtc_ops = { 267 .read_time = da9052_rtc_read_time, 268 .set_time = da9052_rtc_set_time, 269 .read_alarm = da9052_rtc_read_alarm, 270 .set_alarm = da9052_rtc_set_alarm, 271 .alarm_irq_enable = da9052_rtc_alarm_irq_enable, 272 }; 273 274 static int da9052_rtc_probe(struct platform_device *pdev) 275 { 276 struct da9052_rtc *rtc; 277 int ret; 278 279 rtc = devm_kzalloc(&pdev->dev, sizeof(struct da9052_rtc), GFP_KERNEL); 280 if (!rtc) 281 return -ENOMEM; 282 283 rtc->da9052 = dev_get_drvdata(pdev->dev.parent); 284 platform_set_drvdata(pdev, rtc); 285 286 ret = da9052_reg_write(rtc->da9052, DA9052_BBAT_CONT_REG, 0xFE); 287 if (ret < 0) { 288 rtc_err(rtc, 289 "Failed to setup RTC battery charging: %d\n", ret); 290 return ret; 291 } 292 293 ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG, 294 DA9052_ALARM_Y_TICK_ON, 0); 295 if (ret != 0) 296 rtc_err(rtc, "Failed to disable TICKS: %d\n", ret); 297 298 device_init_wakeup(&pdev->dev, true); 299 rtc->rtc = devm_rtc_allocate_device(&pdev->dev); 300 if (IS_ERR(rtc->rtc)) 301 return PTR_ERR(rtc->rtc); 302 303 rtc->rtc->ops = &da9052_rtc_ops; 304 rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; 305 rtc->rtc->range_max = RTC_TIMESTAMP_END_2063; 306 307 ret = rtc_register_device(rtc->rtc); 308 if (ret) 309 return ret; 310 311 ret = da9052_request_irq(rtc->da9052, DA9052_IRQ_ALARM, "ALM", 312 da9052_rtc_irq, rtc); 313 if (ret != 0) { 314 rtc_err(rtc, "irq registration failed: %d\n", ret); 315 return ret; 316 } 317 318 return 0; 319 } 320 321 static struct platform_driver da9052_rtc_driver = { 322 .probe = da9052_rtc_probe, 323 .driver = { 324 .name = "da9052-rtc", 325 }, 326 }; 327 328 module_platform_driver(da9052_rtc_driver); 329 330 MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>"); 331 MODULE_DESCRIPTION("RTC driver for Dialog DA9052 PMIC"); 332 MODULE_LICENSE("GPL"); 333 MODULE_ALIAS("platform:da9052-rtc"); 334