1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Real-time clock driver for MPC5121 4 * 5 * Copyright 2007, Domen Puncer <domen.puncer@telargo.com> 6 * Copyright 2008, Freescale Semiconductor, Inc. All rights reserved. 7 * Copyright 2011, Dmitry Eremin-Solenikov 8 */ 9 10 #include <linux/init.h> 11 #include <linux/module.h> 12 #include <linux/rtc.h> 13 #include <linux/of.h> 14 #include <linux/of_address.h> 15 #include <linux/of_device.h> 16 #include <linux/of_irq.h> 17 #include <linux/of_platform.h> 18 #include <linux/io.h> 19 #include <linux/slab.h> 20 21 struct mpc5121_rtc_regs { 22 u8 set_time; /* RTC + 0x00 */ 23 u8 hour_set; /* RTC + 0x01 */ 24 u8 minute_set; /* RTC + 0x02 */ 25 u8 second_set; /* RTC + 0x03 */ 26 27 u8 set_date; /* RTC + 0x04 */ 28 u8 month_set; /* RTC + 0x05 */ 29 u8 weekday_set; /* RTC + 0x06 */ 30 u8 date_set; /* RTC + 0x07 */ 31 32 u8 write_sw; /* RTC + 0x08 */ 33 u8 sw_set; /* RTC + 0x09 */ 34 u16 year_set; /* RTC + 0x0a */ 35 36 u8 alm_enable; /* RTC + 0x0c */ 37 u8 alm_hour_set; /* RTC + 0x0d */ 38 u8 alm_min_set; /* RTC + 0x0e */ 39 u8 int_enable; /* RTC + 0x0f */ 40 41 u8 reserved1; 42 u8 hour; /* RTC + 0x11 */ 43 u8 minute; /* RTC + 0x12 */ 44 u8 second; /* RTC + 0x13 */ 45 46 u8 month; /* RTC + 0x14 */ 47 u8 wday_mday; /* RTC + 0x15 */ 48 u16 year; /* RTC + 0x16 */ 49 50 u8 int_alm; /* RTC + 0x18 */ 51 u8 int_sw; /* RTC + 0x19 */ 52 u8 alm_status; /* RTC + 0x1a */ 53 u8 sw_minute; /* RTC + 0x1b */ 54 55 u8 bus_error_1; /* RTC + 0x1c */ 56 u8 int_day; /* RTC + 0x1d */ 57 u8 int_min; /* RTC + 0x1e */ 58 u8 int_sec; /* RTC + 0x1f */ 59 60 /* 61 * target_time: 62 * intended to be used for hibernation but hibernation 63 * does not work on silicon rev 1.5 so use it for non-volatile 64 * storage of offset between the actual_time register and linux 65 * time 66 */ 67 u32 target_time; /* RTC + 0x20 */ 68 /* 69 * actual_time: 70 * readonly time since VBAT_RTC was last connected 71 */ 72 u32 actual_time; /* RTC + 0x24 */ 73 u32 keep_alive; /* RTC + 0x28 */ 74 }; 75 76 struct mpc5121_rtc_data { 77 unsigned irq; 78 unsigned irq_periodic; 79 struct mpc5121_rtc_regs __iomem *regs; 80 struct rtc_device *rtc; 81 struct rtc_wkalrm wkalarm; 82 }; 83 84 /* 85 * Update second/minute/hour registers. 86 * 87 * This is just so alarm will work. 88 */ 89 static void mpc5121_rtc_update_smh(struct mpc5121_rtc_regs __iomem *regs, 90 struct rtc_time *tm) 91 { 92 out_8(®s->second_set, tm->tm_sec); 93 out_8(®s->minute_set, tm->tm_min); 94 out_8(®s->hour_set, tm->tm_hour); 95 96 /* set time sequence */ 97 out_8(®s->set_time, 0x1); 98 out_8(®s->set_time, 0x3); 99 out_8(®s->set_time, 0x1); 100 out_8(®s->set_time, 0x0); 101 } 102 103 static int mpc5121_rtc_read_time(struct device *dev, struct rtc_time *tm) 104 { 105 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev); 106 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 107 unsigned long now; 108 109 /* 110 * linux time is actual_time plus the offset saved in target_time 111 */ 112 now = in_be32(®s->actual_time) + in_be32(®s->target_time); 113 114 rtc_time64_to_tm(now, tm); 115 116 /* 117 * update second minute hour registers 118 * so alarms will work 119 */ 120 mpc5121_rtc_update_smh(regs, tm); 121 122 return 0; 123 } 124 125 static int mpc5121_rtc_set_time(struct device *dev, struct rtc_time *tm) 126 { 127 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev); 128 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 129 unsigned long now; 130 131 /* 132 * The actual_time register is read only so we write the offset 133 * between it and linux time to the target_time register. 134 */ 135 now = rtc_tm_to_time64(tm); 136 out_be32(®s->target_time, now - in_be32(®s->actual_time)); 137 138 /* 139 * update second minute hour registers 140 * so alarms will work 141 */ 142 mpc5121_rtc_update_smh(regs, tm); 143 144 return 0; 145 } 146 147 static int mpc5200_rtc_read_time(struct device *dev, struct rtc_time *tm) 148 { 149 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev); 150 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 151 int tmp; 152 153 tm->tm_sec = in_8(®s->second); 154 tm->tm_min = in_8(®s->minute); 155 156 /* 12 hour format? */ 157 if (in_8(®s->hour) & 0x20) 158 tm->tm_hour = (in_8(®s->hour) >> 1) + 159 (in_8(®s->hour) & 1 ? 12 : 0); 160 else 161 tm->tm_hour = in_8(®s->hour); 162 163 tmp = in_8(®s->wday_mday); 164 tm->tm_mday = tmp & 0x1f; 165 tm->tm_mon = in_8(®s->month) - 1; 166 tm->tm_year = in_be16(®s->year) - 1900; 167 tm->tm_wday = (tmp >> 5) % 7; 168 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); 169 tm->tm_isdst = 0; 170 171 return 0; 172 } 173 174 static int mpc5200_rtc_set_time(struct device *dev, struct rtc_time *tm) 175 { 176 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev); 177 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 178 179 mpc5121_rtc_update_smh(regs, tm); 180 181 /* date */ 182 out_8(®s->month_set, tm->tm_mon + 1); 183 out_8(®s->weekday_set, tm->tm_wday ? tm->tm_wday : 7); 184 out_8(®s->date_set, tm->tm_mday); 185 out_be16(®s->year_set, tm->tm_year + 1900); 186 187 /* set date sequence */ 188 out_8(®s->set_date, 0x1); 189 out_8(®s->set_date, 0x3); 190 out_8(®s->set_date, 0x1); 191 out_8(®s->set_date, 0x0); 192 193 return 0; 194 } 195 196 static int mpc5121_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 197 { 198 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev); 199 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 200 201 *alarm = rtc->wkalarm; 202 203 alarm->pending = in_8(®s->alm_status); 204 205 return 0; 206 } 207 208 static int mpc5121_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 209 { 210 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev); 211 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 212 213 /* 214 * the alarm has no seconds so deal with it 215 */ 216 if (alarm->time.tm_sec) { 217 alarm->time.tm_sec = 0; 218 alarm->time.tm_min++; 219 if (alarm->time.tm_min >= 60) { 220 alarm->time.tm_min = 0; 221 alarm->time.tm_hour++; 222 if (alarm->time.tm_hour >= 24) 223 alarm->time.tm_hour = 0; 224 } 225 } 226 227 alarm->time.tm_mday = -1; 228 alarm->time.tm_mon = -1; 229 alarm->time.tm_year = -1; 230 231 out_8(®s->alm_min_set, alarm->time.tm_min); 232 out_8(®s->alm_hour_set, alarm->time.tm_hour); 233 234 out_8(®s->alm_enable, alarm->enabled); 235 236 rtc->wkalarm = *alarm; 237 return 0; 238 } 239 240 static irqreturn_t mpc5121_rtc_handler(int irq, void *dev) 241 { 242 struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev); 243 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 244 245 if (in_8(®s->int_alm)) { 246 /* acknowledge and clear status */ 247 out_8(®s->int_alm, 1); 248 out_8(®s->alm_status, 1); 249 250 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF); 251 return IRQ_HANDLED; 252 } 253 254 return IRQ_NONE; 255 } 256 257 static irqreturn_t mpc5121_rtc_handler_upd(int irq, void *dev) 258 { 259 struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev); 260 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 261 262 if (in_8(®s->int_sec) && (in_8(®s->int_enable) & 0x1)) { 263 /* acknowledge */ 264 out_8(®s->int_sec, 1); 265 266 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_UF); 267 return IRQ_HANDLED; 268 } 269 270 return IRQ_NONE; 271 } 272 273 static int mpc5121_rtc_alarm_irq_enable(struct device *dev, 274 unsigned int enabled) 275 { 276 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev); 277 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 278 int val; 279 280 if (enabled) 281 val = 1; 282 else 283 val = 0; 284 285 out_8(®s->alm_enable, val); 286 rtc->wkalarm.enabled = val; 287 288 return 0; 289 } 290 291 static const struct rtc_class_ops mpc5121_rtc_ops = { 292 .read_time = mpc5121_rtc_read_time, 293 .set_time = mpc5121_rtc_set_time, 294 .read_alarm = mpc5121_rtc_read_alarm, 295 .set_alarm = mpc5121_rtc_set_alarm, 296 .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable, 297 }; 298 299 static const struct rtc_class_ops mpc5200_rtc_ops = { 300 .read_time = mpc5200_rtc_read_time, 301 .set_time = mpc5200_rtc_set_time, 302 .read_alarm = mpc5121_rtc_read_alarm, 303 .set_alarm = mpc5121_rtc_set_alarm, 304 .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable, 305 }; 306 307 static int mpc5121_rtc_probe(struct platform_device *op) 308 { 309 struct mpc5121_rtc_data *rtc; 310 int err = 0; 311 312 rtc = devm_kzalloc(&op->dev, sizeof(*rtc), GFP_KERNEL); 313 if (!rtc) 314 return -ENOMEM; 315 316 rtc->regs = devm_platform_ioremap_resource(op, 0); 317 if (IS_ERR(rtc->regs)) { 318 dev_err(&op->dev, "%s: couldn't map io space\n", __func__); 319 return PTR_ERR(rtc->regs); 320 } 321 322 device_init_wakeup(&op->dev, 1); 323 324 platform_set_drvdata(op, rtc); 325 326 rtc->irq = irq_of_parse_and_map(op->dev.of_node, 1); 327 err = devm_request_irq(&op->dev, rtc->irq, mpc5121_rtc_handler, 0, 328 "mpc5121-rtc", &op->dev); 329 if (err) { 330 dev_err(&op->dev, "%s: could not request irq: %i\n", 331 __func__, rtc->irq); 332 goto out_dispose; 333 } 334 335 rtc->irq_periodic = irq_of_parse_and_map(op->dev.of_node, 0); 336 err = devm_request_irq(&op->dev, rtc->irq_periodic, 337 mpc5121_rtc_handler_upd, 0, "mpc5121-rtc_upd", 338 &op->dev); 339 if (err) { 340 dev_err(&op->dev, "%s: could not request irq: %i\n", 341 __func__, rtc->irq_periodic); 342 goto out_dispose2; 343 } 344 345 rtc->rtc = devm_rtc_allocate_device(&op->dev); 346 if (IS_ERR(rtc->rtc)) { 347 err = PTR_ERR(rtc->rtc); 348 goto out_dispose2; 349 } 350 351 rtc->rtc->ops = &mpc5200_rtc_ops; 352 rtc->rtc->uie_unsupported = 1; 353 rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_0000; 354 rtc->rtc->range_max = 65733206399ULL; /* 4052-12-31 23:59:59 */ 355 356 if (of_device_is_compatible(op->dev.of_node, "fsl,mpc5121-rtc")) { 357 u32 ka; 358 ka = in_be32(&rtc->regs->keep_alive); 359 if (ka & 0x02) { 360 dev_warn(&op->dev, 361 "mpc5121-rtc: Battery or oscillator failure!\n"); 362 out_be32(&rtc->regs->keep_alive, ka); 363 } 364 rtc->rtc->ops = &mpc5121_rtc_ops; 365 /* 366 * This is a limitation of the driver that abuses the target 367 * time register, the actual maximum year for the mpc5121 is 368 * also 4052. 369 */ 370 rtc->rtc->range_min = 0; 371 rtc->rtc->range_max = U32_MAX; 372 } 373 374 err = devm_rtc_register_device(rtc->rtc); 375 if (err) 376 goto out_dispose2; 377 378 return 0; 379 380 out_dispose2: 381 irq_dispose_mapping(rtc->irq_periodic); 382 out_dispose: 383 irq_dispose_mapping(rtc->irq); 384 385 return err; 386 } 387 388 static int mpc5121_rtc_remove(struct platform_device *op) 389 { 390 struct mpc5121_rtc_data *rtc = platform_get_drvdata(op); 391 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 392 393 /* disable interrupt, so there are no nasty surprises */ 394 out_8(®s->alm_enable, 0); 395 out_8(®s->int_enable, in_8(®s->int_enable) & ~0x1); 396 397 irq_dispose_mapping(rtc->irq); 398 irq_dispose_mapping(rtc->irq_periodic); 399 400 return 0; 401 } 402 403 #ifdef CONFIG_OF 404 static const struct of_device_id mpc5121_rtc_match[] = { 405 { .compatible = "fsl,mpc5121-rtc", }, 406 { .compatible = "fsl,mpc5200-rtc", }, 407 {}, 408 }; 409 MODULE_DEVICE_TABLE(of, mpc5121_rtc_match); 410 #endif 411 412 static struct platform_driver mpc5121_rtc_driver = { 413 .driver = { 414 .name = "mpc5121-rtc", 415 .of_match_table = of_match_ptr(mpc5121_rtc_match), 416 }, 417 .probe = mpc5121_rtc_probe, 418 .remove = mpc5121_rtc_remove, 419 }; 420 421 module_platform_driver(mpc5121_rtc_driver); 422 423 MODULE_LICENSE("GPL"); 424 MODULE_AUTHOR("John Rigby <jcrigby@gmail.com>"); 425