1 /* 2 * Copyright 2004-2008 Freescale Semiconductor, Inc. All Rights Reserved. 3 * 4 * The code contained herein is licensed under the GNU General Public 5 * License. You may obtain a copy of the GNU General Public License 6 * Version 2 or later at the following locations: 7 * 8 * http://www.opensource.org/licenses/gpl-license.html 9 * http://www.gnu.org/copyleft/gpl.html 10 */ 11 12 #include <linux/io.h> 13 #include <linux/rtc.h> 14 #include <linux/module.h> 15 #include <linux/slab.h> 16 #include <linux/interrupt.h> 17 #include <linux/platform_device.h> 18 #include <linux/clk.h> 19 #include <linux/of.h> 20 #include <linux/of_device.h> 21 22 #define RTC_INPUT_CLK_32768HZ (0x00 << 5) 23 #define RTC_INPUT_CLK_32000HZ (0x01 << 5) 24 #define RTC_INPUT_CLK_38400HZ (0x02 << 5) 25 26 #define RTC_SW_BIT (1 << 0) 27 #define RTC_ALM_BIT (1 << 2) 28 #define RTC_1HZ_BIT (1 << 4) 29 #define RTC_2HZ_BIT (1 << 7) 30 #define RTC_SAM0_BIT (1 << 8) 31 #define RTC_SAM1_BIT (1 << 9) 32 #define RTC_SAM2_BIT (1 << 10) 33 #define RTC_SAM3_BIT (1 << 11) 34 #define RTC_SAM4_BIT (1 << 12) 35 #define RTC_SAM5_BIT (1 << 13) 36 #define RTC_SAM6_BIT (1 << 14) 37 #define RTC_SAM7_BIT (1 << 15) 38 #define PIT_ALL_ON (RTC_2HZ_BIT | RTC_SAM0_BIT | RTC_SAM1_BIT | \ 39 RTC_SAM2_BIT | RTC_SAM3_BIT | RTC_SAM4_BIT | \ 40 RTC_SAM5_BIT | RTC_SAM6_BIT | RTC_SAM7_BIT) 41 42 #define RTC_ENABLE_BIT (1 << 7) 43 44 #define MAX_PIE_NUM 9 45 #define MAX_PIE_FREQ 512 46 static const u32 PIE_BIT_DEF[MAX_PIE_NUM][2] = { 47 { 2, RTC_2HZ_BIT }, 48 { 4, RTC_SAM0_BIT }, 49 { 8, RTC_SAM1_BIT }, 50 { 16, RTC_SAM2_BIT }, 51 { 32, RTC_SAM3_BIT }, 52 { 64, RTC_SAM4_BIT }, 53 { 128, RTC_SAM5_BIT }, 54 { 256, RTC_SAM6_BIT }, 55 { MAX_PIE_FREQ, RTC_SAM7_BIT }, 56 }; 57 58 #define MXC_RTC_TIME 0 59 #define MXC_RTC_ALARM 1 60 61 #define RTC_HOURMIN 0x00 /* 32bit rtc hour/min counter reg */ 62 #define RTC_SECOND 0x04 /* 32bit rtc seconds counter reg */ 63 #define RTC_ALRM_HM 0x08 /* 32bit rtc alarm hour/min reg */ 64 #define RTC_ALRM_SEC 0x0C /* 32bit rtc alarm seconds reg */ 65 #define RTC_RTCCTL 0x10 /* 32bit rtc control reg */ 66 #define RTC_RTCISR 0x14 /* 32bit rtc interrupt status reg */ 67 #define RTC_RTCIENR 0x18 /* 32bit rtc interrupt enable reg */ 68 #define RTC_STPWCH 0x1C /* 32bit rtc stopwatch min reg */ 69 #define RTC_DAYR 0x20 /* 32bit rtc days counter reg */ 70 #define RTC_DAYALARM 0x24 /* 32bit rtc day alarm reg */ 71 #define RTC_TEST1 0x28 /* 32bit rtc test reg 1 */ 72 #define RTC_TEST2 0x2C /* 32bit rtc test reg 2 */ 73 #define RTC_TEST3 0x30 /* 32bit rtc test reg 3 */ 74 75 enum imx_rtc_type { 76 IMX1_RTC, 77 IMX21_RTC, 78 }; 79 80 struct rtc_plat_data { 81 struct rtc_device *rtc; 82 void __iomem *ioaddr; 83 int irq; 84 struct clk *clk_ref; 85 struct clk *clk_ipg; 86 struct rtc_time g_rtc_alarm; 87 enum imx_rtc_type devtype; 88 }; 89 90 static const struct platform_device_id imx_rtc_devtype[] = { 91 { 92 .name = "imx1-rtc", 93 .driver_data = IMX1_RTC, 94 }, { 95 .name = "imx21-rtc", 96 .driver_data = IMX21_RTC, 97 }, { 98 /* sentinel */ 99 } 100 }; 101 MODULE_DEVICE_TABLE(platform, imx_rtc_devtype); 102 103 #ifdef CONFIG_OF 104 static const struct of_device_id imx_rtc_dt_ids[] = { 105 { .compatible = "fsl,imx1-rtc", .data = (const void *)IMX1_RTC }, 106 { .compatible = "fsl,imx21-rtc", .data = (const void *)IMX21_RTC }, 107 {} 108 }; 109 MODULE_DEVICE_TABLE(of, imx_rtc_dt_ids); 110 #endif 111 112 static inline int is_imx1_rtc(struct rtc_plat_data *data) 113 { 114 return data->devtype == IMX1_RTC; 115 } 116 117 /* 118 * This function is used to obtain the RTC time or the alarm value in 119 * second. 120 */ 121 static time64_t get_alarm_or_time(struct device *dev, int time_alarm) 122 { 123 struct platform_device *pdev = to_platform_device(dev); 124 struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 125 void __iomem *ioaddr = pdata->ioaddr; 126 u32 day = 0, hr = 0, min = 0, sec = 0, hr_min = 0; 127 128 switch (time_alarm) { 129 case MXC_RTC_TIME: 130 day = readw(ioaddr + RTC_DAYR); 131 hr_min = readw(ioaddr + RTC_HOURMIN); 132 sec = readw(ioaddr + RTC_SECOND); 133 break; 134 case MXC_RTC_ALARM: 135 day = readw(ioaddr + RTC_DAYALARM); 136 hr_min = readw(ioaddr + RTC_ALRM_HM) & 0xffff; 137 sec = readw(ioaddr + RTC_ALRM_SEC); 138 break; 139 } 140 141 hr = hr_min >> 8; 142 min = hr_min & 0xff; 143 144 return ((((time64_t)day * 24 + hr) * 60) + min) * 60 + sec; 145 } 146 147 /* 148 * This function sets the RTC alarm value or the time value. 149 */ 150 static void set_alarm_or_time(struct device *dev, int time_alarm, time64_t time) 151 { 152 u32 tod, day, hr, min, sec, temp; 153 struct platform_device *pdev = to_platform_device(dev); 154 struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 155 void __iomem *ioaddr = pdata->ioaddr; 156 157 day = div_s64_rem(time, 86400, &tod); 158 159 /* time is within a day now */ 160 hr = tod / 3600; 161 tod -= hr * 3600; 162 163 /* time is within an hour now */ 164 min = tod / 60; 165 sec = tod - min * 60; 166 167 temp = (hr << 8) + min; 168 169 switch (time_alarm) { 170 case MXC_RTC_TIME: 171 writew(day, ioaddr + RTC_DAYR); 172 writew(sec, ioaddr + RTC_SECOND); 173 writew(temp, ioaddr + RTC_HOURMIN); 174 break; 175 case MXC_RTC_ALARM: 176 writew(day, ioaddr + RTC_DAYALARM); 177 writew(sec, ioaddr + RTC_ALRM_SEC); 178 writew(temp, ioaddr + RTC_ALRM_HM); 179 break; 180 } 181 } 182 183 /* 184 * This function updates the RTC alarm registers and then clears all the 185 * interrupt status bits. 186 */ 187 static void rtc_update_alarm(struct device *dev, struct rtc_time *alrm) 188 { 189 time64_t time; 190 struct platform_device *pdev = to_platform_device(dev); 191 struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 192 void __iomem *ioaddr = pdata->ioaddr; 193 194 time = rtc_tm_to_time64(alrm); 195 196 /* clear all the interrupt status bits */ 197 writew(readw(ioaddr + RTC_RTCISR), ioaddr + RTC_RTCISR); 198 set_alarm_or_time(dev, MXC_RTC_ALARM, time); 199 } 200 201 static void mxc_rtc_irq_enable(struct device *dev, unsigned int bit, 202 unsigned int enabled) 203 { 204 struct platform_device *pdev = to_platform_device(dev); 205 struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 206 void __iomem *ioaddr = pdata->ioaddr; 207 u32 reg; 208 209 spin_lock_irq(&pdata->rtc->irq_lock); 210 reg = readw(ioaddr + RTC_RTCIENR); 211 212 if (enabled) 213 reg |= bit; 214 else 215 reg &= ~bit; 216 217 writew(reg, ioaddr + RTC_RTCIENR); 218 spin_unlock_irq(&pdata->rtc->irq_lock); 219 } 220 221 /* This function is the RTC interrupt service routine. */ 222 static irqreturn_t mxc_rtc_interrupt(int irq, void *dev_id) 223 { 224 struct platform_device *pdev = dev_id; 225 struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 226 void __iomem *ioaddr = pdata->ioaddr; 227 unsigned long flags; 228 u32 status; 229 u32 events = 0; 230 231 spin_lock_irqsave(&pdata->rtc->irq_lock, flags); 232 status = readw(ioaddr + RTC_RTCISR) & readw(ioaddr + RTC_RTCIENR); 233 /* clear interrupt sources */ 234 writew(status, ioaddr + RTC_RTCISR); 235 236 /* update irq data & counter */ 237 if (status & RTC_ALM_BIT) { 238 events |= (RTC_AF | RTC_IRQF); 239 /* RTC alarm should be one-shot */ 240 mxc_rtc_irq_enable(&pdev->dev, RTC_ALM_BIT, 0); 241 } 242 243 if (status & RTC_1HZ_BIT) 244 events |= (RTC_UF | RTC_IRQF); 245 246 if (status & PIT_ALL_ON) 247 events |= (RTC_PF | RTC_IRQF); 248 249 rtc_update_irq(pdata->rtc, 1, events); 250 spin_unlock_irqrestore(&pdata->rtc->irq_lock, flags); 251 252 return IRQ_HANDLED; 253 } 254 255 /* 256 * Clear all interrupts and release the IRQ 257 */ 258 static void mxc_rtc_release(struct device *dev) 259 { 260 struct platform_device *pdev = to_platform_device(dev); 261 struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 262 void __iomem *ioaddr = pdata->ioaddr; 263 264 spin_lock_irq(&pdata->rtc->irq_lock); 265 266 /* Disable all rtc interrupts */ 267 writew(0, ioaddr + RTC_RTCIENR); 268 269 /* Clear all interrupt status */ 270 writew(0xffffffff, ioaddr + RTC_RTCISR); 271 272 spin_unlock_irq(&pdata->rtc->irq_lock); 273 } 274 275 static int mxc_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) 276 { 277 mxc_rtc_irq_enable(dev, RTC_ALM_BIT, enabled); 278 return 0; 279 } 280 281 /* 282 * This function reads the current RTC time into tm in Gregorian date. 283 */ 284 static int mxc_rtc_read_time(struct device *dev, struct rtc_time *tm) 285 { 286 time64_t val; 287 288 /* Avoid roll-over from reading the different registers */ 289 do { 290 val = get_alarm_or_time(dev, MXC_RTC_TIME); 291 } while (val != get_alarm_or_time(dev, MXC_RTC_TIME)); 292 293 rtc_time64_to_tm(val, tm); 294 295 return 0; 296 } 297 298 /* 299 * This function sets the internal RTC time based on tm in Gregorian date. 300 */ 301 static int mxc_rtc_set_mmss(struct device *dev, time64_t time) 302 { 303 struct platform_device *pdev = to_platform_device(dev); 304 struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 305 306 /* 307 * TTC_DAYR register is 9-bit in MX1 SoC, save time and day of year only 308 */ 309 if (is_imx1_rtc(pdata)) { 310 struct rtc_time tm; 311 312 rtc_time64_to_tm(time, &tm); 313 tm.tm_year = 70; 314 time = rtc_tm_to_time64(&tm); 315 } 316 317 /* Avoid roll-over from reading the different registers */ 318 do { 319 set_alarm_or_time(dev, MXC_RTC_TIME, time); 320 } while (time != get_alarm_or_time(dev, MXC_RTC_TIME)); 321 322 return 0; 323 } 324 325 /* 326 * This function reads the current alarm value into the passed in 'alrm' 327 * argument. It updates the alrm's pending field value based on the whether 328 * an alarm interrupt occurs or not. 329 */ 330 static int mxc_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 331 { 332 struct platform_device *pdev = to_platform_device(dev); 333 struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 334 void __iomem *ioaddr = pdata->ioaddr; 335 336 rtc_time64_to_tm(get_alarm_or_time(dev, MXC_RTC_ALARM), &alrm->time); 337 alrm->pending = ((readw(ioaddr + RTC_RTCISR) & RTC_ALM_BIT)) ? 1 : 0; 338 339 return 0; 340 } 341 342 /* 343 * This function sets the RTC alarm based on passed in alrm. 344 */ 345 static int mxc_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 346 { 347 struct platform_device *pdev = to_platform_device(dev); 348 struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 349 350 rtc_update_alarm(dev, &alrm->time); 351 352 memcpy(&pdata->g_rtc_alarm, &alrm->time, sizeof(struct rtc_time)); 353 mxc_rtc_irq_enable(dev, RTC_ALM_BIT, alrm->enabled); 354 355 return 0; 356 } 357 358 /* RTC layer */ 359 static struct rtc_class_ops mxc_rtc_ops = { 360 .release = mxc_rtc_release, 361 .read_time = mxc_rtc_read_time, 362 .set_mmss64 = mxc_rtc_set_mmss, 363 .read_alarm = mxc_rtc_read_alarm, 364 .set_alarm = mxc_rtc_set_alarm, 365 .alarm_irq_enable = mxc_rtc_alarm_irq_enable, 366 }; 367 368 static int mxc_rtc_probe(struct platform_device *pdev) 369 { 370 struct resource *res; 371 struct rtc_device *rtc; 372 struct rtc_plat_data *pdata = NULL; 373 u32 reg; 374 unsigned long rate; 375 int ret; 376 const struct of_device_id *of_id; 377 378 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); 379 if (!pdata) 380 return -ENOMEM; 381 382 of_id = of_match_device(imx_rtc_dt_ids, &pdev->dev); 383 if (of_id) 384 pdata->devtype = (enum imx_rtc_type)of_id->data; 385 else 386 pdata->devtype = pdev->id_entry->driver_data; 387 388 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 389 pdata->ioaddr = devm_ioremap_resource(&pdev->dev, res); 390 if (IS_ERR(pdata->ioaddr)) 391 return PTR_ERR(pdata->ioaddr); 392 393 pdata->clk_ipg = devm_clk_get(&pdev->dev, "ipg"); 394 if (IS_ERR(pdata->clk_ipg)) { 395 dev_err(&pdev->dev, "unable to get ipg clock!\n"); 396 return PTR_ERR(pdata->clk_ipg); 397 } 398 399 ret = clk_prepare_enable(pdata->clk_ipg); 400 if (ret) 401 return ret; 402 403 pdata->clk_ref = devm_clk_get(&pdev->dev, "ref"); 404 if (IS_ERR(pdata->clk_ref)) { 405 dev_err(&pdev->dev, "unable to get ref clock!\n"); 406 ret = PTR_ERR(pdata->clk_ref); 407 goto exit_put_clk_ipg; 408 } 409 410 ret = clk_prepare_enable(pdata->clk_ref); 411 if (ret) 412 goto exit_put_clk_ipg; 413 414 rate = clk_get_rate(pdata->clk_ref); 415 416 if (rate == 32768) 417 reg = RTC_INPUT_CLK_32768HZ; 418 else if (rate == 32000) 419 reg = RTC_INPUT_CLK_32000HZ; 420 else if (rate == 38400) 421 reg = RTC_INPUT_CLK_38400HZ; 422 else { 423 dev_err(&pdev->dev, "rtc clock is not valid (%lu)\n", rate); 424 ret = -EINVAL; 425 goto exit_put_clk_ref; 426 } 427 428 reg |= RTC_ENABLE_BIT; 429 writew(reg, (pdata->ioaddr + RTC_RTCCTL)); 430 if (((readw(pdata->ioaddr + RTC_RTCCTL)) & RTC_ENABLE_BIT) == 0) { 431 dev_err(&pdev->dev, "hardware module can't be enabled!\n"); 432 ret = -EIO; 433 goto exit_put_clk_ref; 434 } 435 436 platform_set_drvdata(pdev, pdata); 437 438 /* Configure and enable the RTC */ 439 pdata->irq = platform_get_irq(pdev, 0); 440 441 if (pdata->irq >= 0 && 442 devm_request_irq(&pdev->dev, pdata->irq, mxc_rtc_interrupt, 443 IRQF_SHARED, pdev->name, pdev) < 0) { 444 dev_warn(&pdev->dev, "interrupt not available.\n"); 445 pdata->irq = -1; 446 } 447 448 if (pdata->irq >= 0) 449 device_init_wakeup(&pdev->dev, 1); 450 451 rtc = devm_rtc_device_register(&pdev->dev, pdev->name, &mxc_rtc_ops, 452 THIS_MODULE); 453 if (IS_ERR(rtc)) { 454 ret = PTR_ERR(rtc); 455 goto exit_put_clk_ref; 456 } 457 458 pdata->rtc = rtc; 459 460 return 0; 461 462 exit_put_clk_ref: 463 clk_disable_unprepare(pdata->clk_ref); 464 exit_put_clk_ipg: 465 clk_disable_unprepare(pdata->clk_ipg); 466 467 return ret; 468 } 469 470 static int mxc_rtc_remove(struct platform_device *pdev) 471 { 472 struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 473 474 clk_disable_unprepare(pdata->clk_ref); 475 clk_disable_unprepare(pdata->clk_ipg); 476 477 return 0; 478 } 479 480 #ifdef CONFIG_PM_SLEEP 481 static int mxc_rtc_suspend(struct device *dev) 482 { 483 struct rtc_plat_data *pdata = dev_get_drvdata(dev); 484 485 if (device_may_wakeup(dev)) 486 enable_irq_wake(pdata->irq); 487 488 return 0; 489 } 490 491 static int mxc_rtc_resume(struct device *dev) 492 { 493 struct rtc_plat_data *pdata = dev_get_drvdata(dev); 494 495 if (device_may_wakeup(dev)) 496 disable_irq_wake(pdata->irq); 497 498 return 0; 499 } 500 #endif 501 502 static SIMPLE_DEV_PM_OPS(mxc_rtc_pm_ops, mxc_rtc_suspend, mxc_rtc_resume); 503 504 static struct platform_driver mxc_rtc_driver = { 505 .driver = { 506 .name = "mxc_rtc", 507 .of_match_table = of_match_ptr(imx_rtc_dt_ids), 508 .pm = &mxc_rtc_pm_ops, 509 }, 510 .id_table = imx_rtc_devtype, 511 .probe = mxc_rtc_probe, 512 .remove = mxc_rtc_remove, 513 }; 514 515 module_platform_driver(mxc_rtc_driver) 516 517 MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>"); 518 MODULE_DESCRIPTION("RTC driver for Freescale MXC"); 519 MODULE_LICENSE("GPL"); 520 521