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 20 struct 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 75 struct 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 */ 88 static 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 } 101 102 static 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 } 123 124 static 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 } 147 148 static 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 } 159 160 static 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 } 191 192 static 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 } 208 209 static 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 } 224 225 static 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 } 242 243 static const struct rtc_class_ops mpc5121_rtc_ops = { 244 .read_time = mpc5121_rtc_read_time, 245 .set_time = mpc5121_rtc_set_time, 246 .read_alarm = mpc5121_rtc_read_alarm, 247 .set_alarm = mpc5121_rtc_set_alarm, 248 .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable, 249 }; 250 251 static int __devinit mpc5121_rtc_probe(struct platform_device *op) 252 { 253 struct mpc5121_rtc_data *rtc; 254 int err = 0; 255 u32 ka; 256 257 rtc = kzalloc(sizeof(*rtc), GFP_KERNEL); 258 if (!rtc) 259 return -ENOMEM; 260 261 rtc->regs = of_iomap(op->dev.of_node, 0); 262 if (!rtc->regs) { 263 dev_err(&op->dev, "%s: couldn't map io space\n", __func__); 264 err = -ENOSYS; 265 goto out_free; 266 } 267 268 device_init_wakeup(&op->dev, 1); 269 270 dev_set_drvdata(&op->dev, rtc); 271 272 rtc->irq = irq_of_parse_and_map(op->dev.of_node, 1); 273 err = request_irq(rtc->irq, mpc5121_rtc_handler, IRQF_DISABLED, 274 "mpc5121-rtc", &op->dev); 275 if (err) { 276 dev_err(&op->dev, "%s: could not request irq: %i\n", 277 __func__, rtc->irq); 278 goto out_dispose; 279 } 280 281 rtc->irq_periodic = irq_of_parse_and_map(op->dev.of_node, 0); 282 err = request_irq(rtc->irq_periodic, mpc5121_rtc_handler_upd, 283 IRQF_DISABLED, "mpc5121-rtc_upd", &op->dev); 284 if (err) { 285 dev_err(&op->dev, "%s: could not request irq: %i\n", 286 __func__, rtc->irq_periodic); 287 goto out_dispose2; 288 } 289 290 ka = in_be32(&rtc->regs->keep_alive); 291 if (ka & 0x02) { 292 dev_warn(&op->dev, 293 "mpc5121-rtc: Battery or oscillator failure!\n"); 294 out_be32(&rtc->regs->keep_alive, ka); 295 } 296 297 rtc->rtc = rtc_device_register("mpc5121-rtc", &op->dev, 298 &mpc5121_rtc_ops, THIS_MODULE); 299 if (IS_ERR(rtc->rtc)) { 300 err = PTR_ERR(rtc->rtc); 301 goto out_free_irq; 302 } 303 304 return 0; 305 306 out_free_irq: 307 free_irq(rtc->irq_periodic, &op->dev); 308 out_dispose2: 309 irq_dispose_mapping(rtc->irq_periodic); 310 free_irq(rtc->irq, &op->dev); 311 out_dispose: 312 irq_dispose_mapping(rtc->irq); 313 iounmap(rtc->regs); 314 out_free: 315 kfree(rtc); 316 317 return err; 318 } 319 320 static int __devexit mpc5121_rtc_remove(struct platform_device *op) 321 { 322 struct mpc5121_rtc_data *rtc = dev_get_drvdata(&op->dev); 323 struct mpc5121_rtc_regs __iomem *regs = rtc->regs; 324 325 /* disable interrupt, so there are no nasty surprises */ 326 out_8(®s->alm_enable, 0); 327 out_8(®s->int_enable, in_8(®s->int_enable) & ~0x1); 328 329 rtc_device_unregister(rtc->rtc); 330 iounmap(rtc->regs); 331 free_irq(rtc->irq, &op->dev); 332 free_irq(rtc->irq_periodic, &op->dev); 333 irq_dispose_mapping(rtc->irq); 334 irq_dispose_mapping(rtc->irq_periodic); 335 dev_set_drvdata(&op->dev, NULL); 336 kfree(rtc); 337 338 return 0; 339 } 340 341 static struct of_device_id mpc5121_rtc_match[] __devinitdata = { 342 { .compatible = "fsl,mpc5121-rtc", }, 343 {}, 344 }; 345 346 static struct platform_driver mpc5121_rtc_driver = { 347 .driver = { 348 .name = "mpc5121-rtc", 349 .owner = THIS_MODULE, 350 .of_match_table = mpc5121_rtc_match, 351 }, 352 .probe = mpc5121_rtc_probe, 353 .remove = __devexit_p(mpc5121_rtc_remove), 354 }; 355 356 static int __init mpc5121_rtc_init(void) 357 { 358 return platform_driver_register(&mpc5121_rtc_driver); 359 } 360 module_init(mpc5121_rtc_init); 361 362 static void __exit mpc5121_rtc_exit(void) 363 { 364 platform_driver_unregister(&mpc5121_rtc_driver); 365 } 366 module_exit(mpc5121_rtc_exit); 367 368 MODULE_LICENSE("GPL"); 369 MODULE_AUTHOR("John Rigby <jcrigby@gmail.com>"); 370