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