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#include <linux/slab.h> 19 20struct mpc5121_rtc_regs { 21 u8 set_time; /* RTC + 0x00 */ 22 u8 hour_set; /* RTC + 0x01 */ 23 u8 minute_set; /* RTC + 0x02 */ 24 u8 second_set; /* RTC + 0x03 */ 25 26 u8 set_date; /* RTC + 0x04 */ 27 u8 month_set; /* RTC + 0x05 */ 28 u8 weekday_set; /* RTC + 0x06 */ 29 u8 date_set; /* RTC + 0x07 */ 30 31 u8 write_sw; /* RTC + 0x08 */ 32 u8 sw_set; /* RTC + 0x09 */ 33 u16 year_set; /* RTC + 0x0a */ 34 35 u8 alm_enable; /* RTC + 0x0c */ 36 u8 alm_hour_set; /* RTC + 0x0d */ 37 u8 alm_min_set; /* RTC + 0x0e */ 38 u8 int_enable; /* RTC + 0x0f */ 39 40 u8 reserved1; 41 u8 hour; /* RTC + 0x11 */ 42 u8 minute; /* RTC + 0x12 */ 43 u8 second; /* RTC + 0x13 */ 44 45 u8 month; /* RTC + 0x14 */ 46 u8 wday_mday; /* RTC + 0x15 */ 47 u16 year; /* RTC + 0x16 */ 48 49 u8 int_alm; /* RTC + 0x18 */ 50 u8 int_sw; /* RTC + 0x19 */ 51 u8 alm_status; /* RTC + 0x1a */ 52 u8 sw_minute; /* RTC + 0x1b */ 53 54 u8 bus_error_1; /* RTC + 0x1c */ 55 u8 int_day; /* RTC + 0x1d */ 56 u8 int_min; /* RTC + 0x1e */ 57 u8 int_sec; /* RTC + 0x1f */ 58 59 /* 60 * target_time: 61 * intended to be used for hibernation but hibernation 62 * does not work on silicon rev 1.5 so use it for non-volatile 63 * storage of offset between the actual_time register and linux 64 * time 65 */ 66 u32 target_time; /* RTC + 0x20 */ 67 /* 68 * actual_time: 69 * readonly time since VBAT_RTC was last connected 70 */ 71 u32 actual_time; /* RTC + 0x24 */ 72 u32 keep_alive; /* RTC + 0x28 */ 73}; 74 75struct mpc5121_rtc_data { 76 unsigned irq; 77 unsigned irq_periodic; 78 struct mpc5121_rtc_regs __iomem *regs; 79 struct rtc_device *rtc; 80 struct rtc_wkalrm wkalarm; 81}; 82 83/* 84 * Update second/minute/hour registers. 85 * 86 * This is just so alarm will work. 87 */ 88static void mpc5121_rtc_update_smh(struct mpc5121_rtc_regs __iomem *regs, 89 struct rtc_time *tm) 90{ 91 out_8(®s->second_set, tm->tm_sec); 92 out_8(®s->minute_set, tm->tm_min); 93 out_8(®s->hour_set, tm->tm_hour); 94 95 /* set time sequence */ 96 out_8(®s->set_time, 0x1); 97 out_8(®s->set_time, 0x3); 98 out_8(®s->set_time, 0x1); 99 out_8(®s->set_time, 0x0); 100} 101 102static int mpc5121_rtc_read_time(struct device *dev, struct rtc_time *tm) 103{ 104 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev); 105 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 106 unsigned long now; 107 108 /* 109 * linux time is actual_time plus the offset saved in target_time 110 */ 111 now = in_be32(®s->actual_time) + in_be32(®s->target_time); 112 113 rtc_time_to_tm(now, tm); 114 115 /* 116 * update second minute hour registers 117 * so alarms will work 118 */ 119 mpc5121_rtc_update_smh(regs, tm); 120 121 return rtc_valid_tm(tm); 122} 123 124static int mpc5121_rtc_set_time(struct device *dev, struct rtc_time *tm) 125{ 126 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev); 127 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 128 int ret; 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 ret = rtc_tm_to_time(tm, &now); 136 if (ret == 0) 137 out_be32(®s->target_time, now - in_be32(®s->actual_time)); 138 139 /* 140 * update second minute hour registers 141 * so alarms will work 142 */ 143 mpc5121_rtc_update_smh(regs, tm); 144 145 return 0; 146} 147 148static int mpc5121_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 149{ 150 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev); 151 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 152 153 *alarm = rtc->wkalarm; 154 155 alarm->pending = in_8(®s->alm_status); 156 157 return 0; 158} 159 160static int mpc5121_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 161{ 162 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev); 163 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 164 165 /* 166 * the alarm has no seconds so deal with it 167 */ 168 if (alarm->time.tm_sec) { 169 alarm->time.tm_sec = 0; 170 alarm->time.tm_min++; 171 if (alarm->time.tm_min >= 60) { 172 alarm->time.tm_min = 0; 173 alarm->time.tm_hour++; 174 if (alarm->time.tm_hour >= 24) 175 alarm->time.tm_hour = 0; 176 } 177 } 178 179 alarm->time.tm_mday = -1; 180 alarm->time.tm_mon = -1; 181 alarm->time.tm_year = -1; 182 183 out_8(®s->alm_min_set, alarm->time.tm_min); 184 out_8(®s->alm_hour_set, alarm->time.tm_hour); 185 186 out_8(®s->alm_enable, alarm->enabled); 187 188 rtc->wkalarm = *alarm; 189 return 0; 190} 191 192static irqreturn_t mpc5121_rtc_handler(int irq, void *dev) 193{ 194 struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev); 195 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 196 197 if (in_8(®s->int_alm)) { 198 /* acknowledge and clear status */ 199 out_8(®s->int_alm, 1); 200 out_8(®s->alm_status, 1); 201 202 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF); 203 return IRQ_HANDLED; 204 } 205 206 return IRQ_NONE; 207} 208 209static irqreturn_t mpc5121_rtc_handler_upd(int irq, void *dev) 210{ 211 struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev); 212 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 213 214 if (in_8(®s->int_sec) && (in_8(®s->int_enable) & 0x1)) { 215 /* acknowledge */ 216 out_8(®s->int_sec, 1); 217 218 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_UF); 219 return IRQ_HANDLED; 220 } 221 222 return IRQ_NONE; 223} 224 225static int mpc5121_rtc_alarm_irq_enable(struct device *dev, 226 unsigned int enabled) 227{ 228 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev); 229 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 230 int val; 231 232 if (enabled) 233 val = 1; 234 else 235 val = 0; 236 237 out_8(®s->alm_enable, val); 238 rtc->wkalarm.enabled = val; 239 240 return 0; 241} 242 243static int mpc5121_rtc_update_irq_enable(struct device *dev, 244 unsigned int enabled) 245{ 246 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev); 247 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 248 int val; 249 250 val = in_8(®s->int_enable); 251 252 if (enabled) 253 val = (val & ~0x8) | 0x1; 254 else 255 val &= ~0x1; 256 257 out_8(®s->int_enable, val); 258 259 return 0; 260} 261 262static const struct rtc_class_ops mpc5121_rtc_ops = { 263 .read_time = mpc5121_rtc_read_time, 264 .set_time = mpc5121_rtc_set_time, 265 .read_alarm = mpc5121_rtc_read_alarm, 266 .set_alarm = mpc5121_rtc_set_alarm, 267 .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable, 268 .update_irq_enable = mpc5121_rtc_update_irq_enable, 269}; 270 271static int __devinit mpc5121_rtc_probe(struct platform_device *op, 272 const struct of_device_id *match) 273{ 274 struct mpc5121_rtc_data *rtc; 275 int err = 0; 276 u32 ka; 277 278 rtc = kzalloc(sizeof(*rtc), GFP_KERNEL); 279 if (!rtc) 280 return -ENOMEM; 281 282 rtc->regs = of_iomap(op->dev.of_node, 0); 283 if (!rtc->regs) { 284 dev_err(&op->dev, "%s: couldn't map io space\n", __func__); 285 err = -ENOSYS; 286 goto out_free; 287 } 288 289 device_init_wakeup(&op->dev, 1); 290 291 dev_set_drvdata(&op->dev, rtc); 292 293 rtc->irq = irq_of_parse_and_map(op->dev.of_node, 1); 294 err = request_irq(rtc->irq, mpc5121_rtc_handler, IRQF_DISABLED, 295 "mpc5121-rtc", &op->dev); 296 if (err) { 297 dev_err(&op->dev, "%s: could not request irq: %i\n", 298 __func__, rtc->irq); 299 goto out_dispose; 300 } 301 302 rtc->irq_periodic = irq_of_parse_and_map(op->dev.of_node, 0); 303 err = request_irq(rtc->irq_periodic, mpc5121_rtc_handler_upd, 304 IRQF_DISABLED, "mpc5121-rtc_upd", &op->dev); 305 if (err) { 306 dev_err(&op->dev, "%s: could not request irq: %i\n", 307 __func__, rtc->irq_periodic); 308 goto out_dispose2; 309 } 310 311 ka = in_be32(&rtc->regs->keep_alive); 312 if (ka & 0x02) { 313 dev_warn(&op->dev, 314 "mpc5121-rtc: Battery or oscillator failure!\n"); 315 out_be32(&rtc->regs->keep_alive, ka); 316 } 317 318 rtc->rtc = rtc_device_register("mpc5121-rtc", &op->dev, 319 &mpc5121_rtc_ops, THIS_MODULE); 320 if (IS_ERR(rtc->rtc)) { 321 err = PTR_ERR(rtc->rtc); 322 goto out_free_irq; 323 } 324 325 return 0; 326 327out_free_irq: 328 free_irq(rtc->irq_periodic, &op->dev); 329out_dispose2: 330 irq_dispose_mapping(rtc->irq_periodic); 331 free_irq(rtc->irq, &op->dev); 332out_dispose: 333 irq_dispose_mapping(rtc->irq); 334 iounmap(rtc->regs); 335out_free: 336 kfree(rtc); 337 338 return err; 339} 340 341static int __devexit mpc5121_rtc_remove(struct platform_device *op) 342{ 343 struct mpc5121_rtc_data *rtc = dev_get_drvdata(&op->dev); 344 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 345 346 /* disable interrupt, so there are no nasty surprises */ 347 out_8(®s->alm_enable, 0); 348 out_8(®s->int_enable, in_8(®s->int_enable) & ~0x1); 349 350 rtc_device_unregister(rtc->rtc); 351 iounmap(rtc->regs); 352 free_irq(rtc->irq, &op->dev); 353 free_irq(rtc->irq_periodic, &op->dev); 354 irq_dispose_mapping(rtc->irq); 355 irq_dispose_mapping(rtc->irq_periodic); 356 dev_set_drvdata(&op->dev, NULL); 357 kfree(rtc); 358 359 return 0; 360} 361 362static struct of_device_id mpc5121_rtc_match[] __devinitdata = { 363 { .compatible = "fsl,mpc5121-rtc", }, 364 {}, 365}; 366 367static struct of_platform_driver mpc5121_rtc_driver = { 368 .driver = { 369 .name = "mpc5121-rtc", 370 .owner = THIS_MODULE, 371 .of_match_table = mpc5121_rtc_match, 372 }, 373 .probe = mpc5121_rtc_probe, 374 .remove = __devexit_p(mpc5121_rtc_remove), 375}; 376 377static int __init mpc5121_rtc_init(void) 378{ 379 return of_register_platform_driver(&mpc5121_rtc_driver); 380} 381module_init(mpc5121_rtc_init); 382 383static void __exit mpc5121_rtc_exit(void) 384{ 385 of_unregister_platform_driver(&mpc5121_rtc_driver); 386} 387module_exit(mpc5121_rtc_exit); 388 389MODULE_LICENSE("GPL"); 390MODULE_AUTHOR("John Rigby <jcrigby@gmail.com>"); 391