1 /* 2 * Real-time clock driver for MPC5121 3 * 4 * Copyright 2007, Domen Puncer <domen.puncer@telargo.com> 5 * Copyright 2008, Freescale Semiconductor, Inc. All rights reserved. 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 */ 11 12 #include <linux/init.h> 13 #include <linux/module.h> 14 #include <linux/rtc.h> 15 #include <linux/of_device.h> 16 #include <linux/of_platform.h> 17 #include <linux/io.h> 18 19 struct mpc5121_rtc_regs { 20 u8 set_time; /* RTC + 0x00 */ 21 u8 hour_set; /* RTC + 0x01 */ 22 u8 minute_set; /* RTC + 0x02 */ 23 u8 second_set; /* RTC + 0x03 */ 24 25 u8 set_date; /* RTC + 0x04 */ 26 u8 month_set; /* RTC + 0x05 */ 27 u8 weekday_set; /* RTC + 0x06 */ 28 u8 date_set; /* RTC + 0x07 */ 29 30 u8 write_sw; /* RTC + 0x08 */ 31 u8 sw_set; /* RTC + 0x09 */ 32 u16 year_set; /* RTC + 0x0a */ 33 34 u8 alm_enable; /* RTC + 0x0c */ 35 u8 alm_hour_set; /* RTC + 0x0d */ 36 u8 alm_min_set; /* RTC + 0x0e */ 37 u8 int_enable; /* RTC + 0x0f */ 38 39 u8 reserved1; 40 u8 hour; /* RTC + 0x11 */ 41 u8 minute; /* RTC + 0x12 */ 42 u8 second; /* RTC + 0x13 */ 43 44 u8 month; /* RTC + 0x14 */ 45 u8 wday_mday; /* RTC + 0x15 */ 46 u16 year; /* RTC + 0x16 */ 47 48 u8 int_alm; /* RTC + 0x18 */ 49 u8 int_sw; /* RTC + 0x19 */ 50 u8 alm_status; /* RTC + 0x1a */ 51 u8 sw_minute; /* RTC + 0x1b */ 52 53 u8 bus_error_1; /* RTC + 0x1c */ 54 u8 int_day; /* RTC + 0x1d */ 55 u8 int_min; /* RTC + 0x1e */ 56 u8 int_sec; /* RTC + 0x1f */ 57 58 /* 59 * target_time: 60 * intended to be used for hibernation but hibernation 61 * does not work on silicon rev 1.5 so use it for non-volatile 62 * storage of offset between the actual_time register and linux 63 * time 64 */ 65 u32 target_time; /* RTC + 0x20 */ 66 /* 67 * actual_time: 68 * readonly time since VBAT_RTC was last connected 69 */ 70 u32 actual_time; /* RTC + 0x24 */ 71 u32 keep_alive; /* RTC + 0x28 */ 72 }; 73 74 struct mpc5121_rtc_data { 75 unsigned irq; 76 unsigned irq_periodic; 77 struct mpc5121_rtc_regs __iomem *regs; 78 struct rtc_device *rtc; 79 struct rtc_wkalrm wkalarm; 80 }; 81 82 /* 83 * Update second/minute/hour registers. 84 * 85 * This is just so alarm will work. 86 */ 87 static void mpc5121_rtc_update_smh(struct mpc5121_rtc_regs __iomem *regs, 88 struct rtc_time *tm) 89 { 90 out_8(®s->second_set, tm->tm_sec); 91 out_8(®s->minute_set, tm->tm_min); 92 out_8(®s->hour_set, tm->tm_hour); 93 94 /* set time sequence */ 95 out_8(®s->set_time, 0x1); 96 out_8(®s->set_time, 0x3); 97 out_8(®s->set_time, 0x1); 98 out_8(®s->set_time, 0x0); 99 } 100 101 static int mpc5121_rtc_read_time(struct device *dev, struct rtc_time *tm) 102 { 103 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev); 104 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 105 unsigned long now; 106 107 /* 108 * linux time is actual_time plus the offset saved in target_time 109 */ 110 now = in_be32(®s->actual_time) + in_be32(®s->target_time); 111 112 rtc_time_to_tm(now, tm); 113 114 /* 115 * update second minute hour registers 116 * so alarms will work 117 */ 118 mpc5121_rtc_update_smh(regs, tm); 119 120 return rtc_valid_tm(tm); 121 } 122 123 static int mpc5121_rtc_set_time(struct device *dev, struct rtc_time *tm) 124 { 125 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev); 126 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 127 int ret; 128 unsigned long now; 129 130 /* 131 * The actual_time register is read only so we write the offset 132 * between it and linux time to the target_time register. 133 */ 134 ret = rtc_tm_to_time(tm, &now); 135 if (ret == 0) 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 mpc5121_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 148 { 149 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev); 150 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 151 152 *alarm = rtc->wkalarm; 153 154 alarm->pending = in_8(®s->alm_status); 155 156 return 0; 157 } 158 159 static int mpc5121_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 160 { 161 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev); 162 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 163 164 /* 165 * the alarm has no seconds so deal with it 166 */ 167 if (alarm->time.tm_sec) { 168 alarm->time.tm_sec = 0; 169 alarm->time.tm_min++; 170 if (alarm->time.tm_min >= 60) { 171 alarm->time.tm_min = 0; 172 alarm->time.tm_hour++; 173 if (alarm->time.tm_hour >= 24) 174 alarm->time.tm_hour = 0; 175 } 176 } 177 178 alarm->time.tm_mday = -1; 179 alarm->time.tm_mon = -1; 180 alarm->time.tm_year = -1; 181 182 out_8(®s->alm_min_set, alarm->time.tm_min); 183 out_8(®s->alm_hour_set, alarm->time.tm_hour); 184 185 out_8(®s->alm_enable, alarm->enabled); 186 187 rtc->wkalarm = *alarm; 188 return 0; 189 } 190 191 static irqreturn_t mpc5121_rtc_handler(int irq, void *dev) 192 { 193 struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev); 194 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 195 196 if (in_8(®s->int_alm)) { 197 /* acknowledge and clear status */ 198 out_8(®s->int_alm, 1); 199 out_8(®s->alm_status, 1); 200 201 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF); 202 return IRQ_HANDLED; 203 } 204 205 return IRQ_NONE; 206 } 207 208 static irqreturn_t mpc5121_rtc_handler_upd(int irq, void *dev) 209 { 210 struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev); 211 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 212 213 if (in_8(®s->int_sec) && (in_8(®s->int_enable) & 0x1)) { 214 /* acknowledge */ 215 out_8(®s->int_sec, 1); 216 217 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_UF); 218 return IRQ_HANDLED; 219 } 220 221 return IRQ_NONE; 222 } 223 224 static int mpc5121_rtc_alarm_irq_enable(struct device *dev, 225 unsigned int enabled) 226 { 227 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev); 228 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 229 int val; 230 231 if (enabled) 232 val = 1; 233 else 234 val = 0; 235 236 out_8(®s->alm_enable, val); 237 rtc->wkalarm.enabled = val; 238 239 return 0; 240 } 241 242 static int mpc5121_rtc_update_irq_enable(struct device *dev, 243 unsigned int enabled) 244 { 245 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev); 246 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 247 int val; 248 249 val = in_8(®s->int_enable); 250 251 if (enabled) 252 val = (val & ~0x8) | 0x1; 253 else 254 val &= ~0x1; 255 256 out_8(®s->int_enable, val); 257 258 return 0; 259 } 260 261 static const struct rtc_class_ops mpc5121_rtc_ops = { 262 .read_time = mpc5121_rtc_read_time, 263 .set_time = mpc5121_rtc_set_time, 264 .read_alarm = mpc5121_rtc_read_alarm, 265 .set_alarm = mpc5121_rtc_set_alarm, 266 .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable, 267 .update_irq_enable = mpc5121_rtc_update_irq_enable, 268 }; 269 270 static int __devinit mpc5121_rtc_probe(struct of_device *op, 271 const struct of_device_id *match) 272 { 273 struct mpc5121_rtc_data *rtc; 274 int err = 0; 275 u32 ka; 276 277 rtc = kzalloc(sizeof(*rtc), GFP_KERNEL); 278 if (!rtc) 279 return -ENOMEM; 280 281 rtc->regs = of_iomap(op->node, 0); 282 if (!rtc->regs) { 283 dev_err(&op->dev, "%s: couldn't map io space\n", __func__); 284 err = -ENOSYS; 285 goto out_free; 286 } 287 288 device_init_wakeup(&op->dev, 1); 289 290 dev_set_drvdata(&op->dev, rtc); 291 292 rtc->irq = irq_of_parse_and_map(op->node, 1); 293 err = request_irq(rtc->irq, mpc5121_rtc_handler, IRQF_DISABLED, 294 "mpc5121-rtc", &op->dev); 295 if (err) { 296 dev_err(&op->dev, "%s: could not request irq: %i\n", 297 __func__, rtc->irq); 298 goto out_dispose; 299 } 300 301 rtc->irq_periodic = irq_of_parse_and_map(op->node, 0); 302 err = request_irq(rtc->irq_periodic, mpc5121_rtc_handler_upd, 303 IRQF_DISABLED, "mpc5121-rtc_upd", &op->dev); 304 if (err) { 305 dev_err(&op->dev, "%s: could not request irq: %i\n", 306 __func__, rtc->irq_periodic); 307 goto out_dispose2; 308 } 309 310 ka = in_be32(&rtc->regs->keep_alive); 311 if (ka & 0x02) { 312 dev_warn(&op->dev, 313 "mpc5121-rtc: Battery or oscillator failure!\n"); 314 out_be32(&rtc->regs->keep_alive, ka); 315 } 316 317 rtc->rtc = rtc_device_register("mpc5121-rtc", &op->dev, 318 &mpc5121_rtc_ops, THIS_MODULE); 319 if (IS_ERR(rtc->rtc)) { 320 err = PTR_ERR(rtc->rtc); 321 goto out_free_irq; 322 } 323 324 return 0; 325 326 out_free_irq: 327 free_irq(rtc->irq_periodic, &op->dev); 328 out_dispose2: 329 irq_dispose_mapping(rtc->irq_periodic); 330 free_irq(rtc->irq, &op->dev); 331 out_dispose: 332 irq_dispose_mapping(rtc->irq); 333 iounmap(rtc->regs); 334 out_free: 335 kfree(rtc); 336 337 return err; 338 } 339 340 static int __devexit mpc5121_rtc_remove(struct of_device *op) 341 { 342 struct mpc5121_rtc_data *rtc = dev_get_drvdata(&op->dev); 343 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 344 345 /* disable interrupt, so there are no nasty surprises */ 346 out_8(®s->alm_enable, 0); 347 out_8(®s->int_enable, in_8(®s->int_enable) & ~0x1); 348 349 rtc_device_unregister(rtc->rtc); 350 iounmap(rtc->regs); 351 free_irq(rtc->irq, &op->dev); 352 free_irq(rtc->irq_periodic, &op->dev); 353 irq_dispose_mapping(rtc->irq); 354 irq_dispose_mapping(rtc->irq_periodic); 355 dev_set_drvdata(&op->dev, NULL); 356 kfree(rtc); 357 358 return 0; 359 } 360 361 static struct of_device_id mpc5121_rtc_match[] __devinitdata = { 362 { .compatible = "fsl,mpc5121-rtc", }, 363 {}, 364 }; 365 366 static struct of_platform_driver mpc5121_rtc_driver = { 367 .owner = THIS_MODULE, 368 .name = "mpc5121-rtc", 369 .match_table = mpc5121_rtc_match, 370 .probe = mpc5121_rtc_probe, 371 .remove = __devexit_p(mpc5121_rtc_remove), 372 }; 373 374 static int __init mpc5121_rtc_init(void) 375 { 376 return of_register_platform_driver(&mpc5121_rtc_driver); 377 } 378 module_init(mpc5121_rtc_init); 379 380 static void __exit mpc5121_rtc_exit(void) 381 { 382 of_unregister_platform_driver(&mpc5121_rtc_driver); 383 } 384 module_exit(mpc5121_rtc_exit); 385 386 MODULE_LICENSE("GPL"); 387 MODULE_AUTHOR("John Rigby <jcrigby@gmail.com>"); 388