drivers/rtc/rtc-mxc.c

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This source file includes following definitions.
is_imx1_rtc
get_alarm_or_time
set_alarm_or_time
rtc_update_alarm
mxc_rtc_irq_enable
mxc_rtc_interrupt
mxc_rtc_alarm_irq_enable
mxc_rtc_read_time
mxc_rtc_set_time
mxc_rtc_read_alarm
mxc_rtc_set_alarm
mxc_rtc_probe
mxc_rtc_remove
   1 // SPDX-License-Identifier: GPL-2.0+
   2 //
   3 // Copyright 2004-2008 Freescale Semiconductor, Inc. All Rights Reserved.
   4 
   5 #include <linux/io.h>
   6 #include <linux/rtc.h>
   7 #include <linux/module.h>
   8 #include <linux/slab.h>
   9 #include <linux/interrupt.h>
  10 #include <linux/platform_device.h>
  11 #include <linux/pm_wakeirq.h>
  12 #include <linux/clk.h>
  13 #include <linux/of.h>
  14 #include <linux/of_device.h>
  15 
  16 #define RTC_INPUT_CLK_32768HZ   (0x00 << 5)
  17 #define RTC_INPUT_CLK_32000HZ   (0x01 << 5)
  18 #define RTC_INPUT_CLK_38400HZ   (0x02 << 5)
  19 
  20 #define RTC_SW_BIT      (1 << 0)
  21 #define RTC_ALM_BIT     (1 << 2)
  22 #define RTC_1HZ_BIT     (1 << 4)
  23 #define RTC_2HZ_BIT     (1 << 7)
  24 #define RTC_SAM0_BIT    (1 << 8)
  25 #define RTC_SAM1_BIT    (1 << 9)
  26 #define RTC_SAM2_BIT    (1 << 10)
  27 #define RTC_SAM3_BIT    (1 << 11)
  28 #define RTC_SAM4_BIT    (1 << 12)
  29 #define RTC_SAM5_BIT    (1 << 13)
  30 #define RTC_SAM6_BIT    (1 << 14)
  31 #define RTC_SAM7_BIT    (1 << 15)
  32 #define PIT_ALL_ON      (RTC_2HZ_BIT | RTC_SAM0_BIT | RTC_SAM1_BIT | \
  33                          RTC_SAM2_BIT | RTC_SAM3_BIT | RTC_SAM4_BIT | \
  34                          RTC_SAM5_BIT | RTC_SAM6_BIT | RTC_SAM7_BIT)
  35 
  36 #define RTC_ENABLE_BIT  (1 << 7)
  37 
  38 #define MAX_PIE_NUM     9
  39 #define MAX_PIE_FREQ    512
  40 
  41 #define MXC_RTC_TIME    0
  42 #define MXC_RTC_ALARM   1
  43 
  44 #define RTC_HOURMIN     0x00    /*  32bit rtc hour/min counter reg */
  45 #define RTC_SECOND      0x04    /*  32bit rtc seconds counter reg */
  46 #define RTC_ALRM_HM     0x08    /*  32bit rtc alarm hour/min reg */
  47 #define RTC_ALRM_SEC    0x0C    /*  32bit rtc alarm seconds reg */
  48 #define RTC_RTCCTL      0x10    /*  32bit rtc control reg */
  49 #define RTC_RTCISR      0x14    /*  32bit rtc interrupt status reg */
  50 #define RTC_RTCIENR     0x18    /*  32bit rtc interrupt enable reg */
  51 #define RTC_STPWCH      0x1C    /*  32bit rtc stopwatch min reg */
  52 #define RTC_DAYR        0x20    /*  32bit rtc days counter reg */
  53 #define RTC_DAYALARM    0x24    /*  32bit rtc day alarm reg */
  54 #define RTC_TEST1       0x28    /*  32bit rtc test reg 1 */
  55 #define RTC_TEST2       0x2C    /*  32bit rtc test reg 2 */
  56 #define RTC_TEST3       0x30    /*  32bit rtc test reg 3 */
  57 
  58 enum imx_rtc_type {
  59         IMX1_RTC,
  60         IMX21_RTC,
  61 };
  62 
  63 struct rtc_plat_data {
  64         struct rtc_device *rtc;
  65         void __iomem *ioaddr;
  66         int irq;
  67         struct clk *clk_ref;
  68         struct clk *clk_ipg;
  69         struct rtc_time g_rtc_alarm;
  70         enum imx_rtc_type devtype;
  71 };
  72 
  73 static const struct platform_device_id imx_rtc_devtype[] = {
  74         {
  75                 .name = "imx1-rtc",
  76                 .driver_data = IMX1_RTC,
  77         }, {
  78                 .name = "imx21-rtc",
  79                 .driver_data = IMX21_RTC,
  80         }, {
  81                 /* sentinel */
  82         }
  83 };
  84 MODULE_DEVICE_TABLE(platform, imx_rtc_devtype);
  85 
  86 #ifdef CONFIG_OF
  87 static const struct of_device_id imx_rtc_dt_ids[] = {
  88         { .compatible = "fsl,imx1-rtc", .data = (const void *)IMX1_RTC },
  89         { .compatible = "fsl,imx21-rtc", .data = (const void *)IMX21_RTC },
  90         {}
  91 };
  92 MODULE_DEVICE_TABLE(of, imx_rtc_dt_ids);
  93 #endif
  94 
  95 static inline int is_imx1_rtc(struct rtc_plat_data *data)
  96 {
  97         return data->devtype == IMX1_RTC;
  98 }
  99 
 100 /*
 101  * This function is used to obtain the RTC time or the alarm value in
 102  * second.
 103  */
 104 static time64_t get_alarm_or_time(struct device *dev, int time_alarm)
 105 {
 106         struct rtc_plat_data *pdata = dev_get_drvdata(dev);
 107         void __iomem *ioaddr = pdata->ioaddr;
 108         u32 day = 0, hr = 0, min = 0, sec = 0, hr_min = 0;
 109 
 110         switch (time_alarm) {
 111         case MXC_RTC_TIME:
 112                 day = readw(ioaddr + RTC_DAYR);
 113                 hr_min = readw(ioaddr + RTC_HOURMIN);
 114                 sec = readw(ioaddr + RTC_SECOND);
 115                 break;
 116         case MXC_RTC_ALARM:
 117                 day = readw(ioaddr + RTC_DAYALARM);
 118                 hr_min = readw(ioaddr + RTC_ALRM_HM) & 0xffff;
 119                 sec = readw(ioaddr + RTC_ALRM_SEC);
 120                 break;
 121         }
 122 
 123         hr = hr_min >> 8;
 124         min = hr_min & 0xff;
 125 
 126         return ((((time64_t)day * 24 + hr) * 60) + min) * 60 + sec;
 127 }
 128 
 129 /*
 130  * This function sets the RTC alarm value or the time value.
 131  */
 132 static void set_alarm_or_time(struct device *dev, int time_alarm, time64_t time)
 133 {
 134         u32 tod, day, hr, min, sec, temp;
 135         struct rtc_plat_data *pdata = dev_get_drvdata(dev);
 136         void __iomem *ioaddr = pdata->ioaddr;
 137 
 138         day = div_s64_rem(time, 86400, &tod);
 139 
 140         /* time is within a day now */
 141         hr = tod / 3600;
 142         tod -= hr * 3600;
 143 
 144         /* time is within an hour now */
 145         min = tod / 60;
 146         sec = tod - min * 60;
 147 
 148         temp = (hr << 8) + min;
 149 
 150         switch (time_alarm) {
 151         case MXC_RTC_TIME:
 152                 writew(day, ioaddr + RTC_DAYR);
 153                 writew(sec, ioaddr + RTC_SECOND);
 154                 writew(temp, ioaddr + RTC_HOURMIN);
 155                 break;
 156         case MXC_RTC_ALARM:
 157                 writew(day, ioaddr + RTC_DAYALARM);
 158                 writew(sec, ioaddr + RTC_ALRM_SEC);
 159                 writew(temp, ioaddr + RTC_ALRM_HM);
 160                 break;
 161         }
 162 }
 163 
 164 /*
 165  * This function updates the RTC alarm registers and then clears all the
 166  * interrupt status bits.
 167  */
 168 static void rtc_update_alarm(struct device *dev, struct rtc_time *alrm)
 169 {
 170         time64_t time;
 171         struct rtc_plat_data *pdata = dev_get_drvdata(dev);
 172         void __iomem *ioaddr = pdata->ioaddr;
 173 
 174         time = rtc_tm_to_time64(alrm);
 175 
 176         /* clear all the interrupt status bits */
 177         writew(readw(ioaddr + RTC_RTCISR), ioaddr + RTC_RTCISR);
 178         set_alarm_or_time(dev, MXC_RTC_ALARM, time);
 179 }
 180 
 181 static void mxc_rtc_irq_enable(struct device *dev, unsigned int bit,
 182                                 unsigned int enabled)
 183 {
 184         struct rtc_plat_data *pdata = dev_get_drvdata(dev);
 185         void __iomem *ioaddr = pdata->ioaddr;
 186         u32 reg;
 187         unsigned long flags;
 188 
 189         spin_lock_irqsave(&pdata->rtc->irq_lock, flags);
 190         reg = readw(ioaddr + RTC_RTCIENR);
 191 
 192         if (enabled)
 193                 reg |= bit;
 194         else
 195                 reg &= ~bit;
 196 
 197         writew(reg, ioaddr + RTC_RTCIENR);
 198         spin_unlock_irqrestore(&pdata->rtc->irq_lock, flags);
 199 }
 200 
 201 /* This function is the RTC interrupt service routine. */
 202 static irqreturn_t mxc_rtc_interrupt(int irq, void *dev_id)
 203 {
 204         struct platform_device *pdev = dev_id;
 205         struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 206         void __iomem *ioaddr = pdata->ioaddr;
 207         unsigned long flags;
 208         u32 status;
 209         u32 events = 0;
 210 
 211         spin_lock_irqsave(&pdata->rtc->irq_lock, flags);
 212         status = readw(ioaddr + RTC_RTCISR) & readw(ioaddr + RTC_RTCIENR);
 213         /* clear interrupt sources */
 214         writew(status, ioaddr + RTC_RTCISR);
 215 
 216         /* update irq data & counter */
 217         if (status & RTC_ALM_BIT) {
 218                 events |= (RTC_AF | RTC_IRQF);
 219                 /* RTC alarm should be one-shot */
 220                 mxc_rtc_irq_enable(&pdev->dev, RTC_ALM_BIT, 0);
 221         }
 222 
 223         if (status & PIT_ALL_ON)
 224                 events |= (RTC_PF | RTC_IRQF);
 225 
 226         rtc_update_irq(pdata->rtc, 1, events);
 227         spin_unlock_irqrestore(&pdata->rtc->irq_lock, flags);
 228 
 229         return IRQ_HANDLED;
 230 }
 231 
 232 static int mxc_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 233 {
 234         mxc_rtc_irq_enable(dev, RTC_ALM_BIT, enabled);
 235         return 0;
 236 }
 237 
 238 /*
 239  * This function reads the current RTC time into tm in Gregorian date.
 240  */
 241 static int mxc_rtc_read_time(struct device *dev, struct rtc_time *tm)
 242 {
 243         time64_t val;
 244 
 245         /* Avoid roll-over from reading the different registers */
 246         do {
 247                 val = get_alarm_or_time(dev, MXC_RTC_TIME);
 248         } while (val != get_alarm_or_time(dev, MXC_RTC_TIME));
 249 
 250         rtc_time64_to_tm(val, tm);
 251 
 252         return 0;
 253 }
 254 
 255 /*
 256  * This function sets the internal RTC time based on tm in Gregorian date.
 257  */
 258 static int mxc_rtc_set_time(struct device *dev, struct rtc_time *tm)
 259 {
 260         time64_t time = rtc_tm_to_time64(tm);
 261 
 262         /* Avoid roll-over from reading the different registers */
 263         do {
 264                 set_alarm_or_time(dev, MXC_RTC_TIME, time);
 265         } while (time != get_alarm_or_time(dev, MXC_RTC_TIME));
 266 
 267         return 0;
 268 }
 269 
 270 /*
 271  * This function reads the current alarm value into the passed in 'alrm'
 272  * argument. It updates the alrm's pending field value based on the whether
 273  * an alarm interrupt occurs or not.
 274  */
 275 static int mxc_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 276 {
 277         struct rtc_plat_data *pdata = dev_get_drvdata(dev);
 278         void __iomem *ioaddr = pdata->ioaddr;
 279 
 280         rtc_time64_to_tm(get_alarm_or_time(dev, MXC_RTC_ALARM), &alrm->time);
 281         alrm->pending = ((readw(ioaddr + RTC_RTCISR) & RTC_ALM_BIT)) ? 1 : 0;
 282 
 283         return 0;
 284 }
 285 
 286 /*
 287  * This function sets the RTC alarm based on passed in alrm.
 288  */
 289 static int mxc_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 290 {
 291         struct rtc_plat_data *pdata = dev_get_drvdata(dev);
 292 
 293         rtc_update_alarm(dev, &alrm->time);
 294 
 295         memcpy(&pdata->g_rtc_alarm, &alrm->time, sizeof(struct rtc_time));
 296         mxc_rtc_irq_enable(dev, RTC_ALM_BIT, alrm->enabled);
 297 
 298         return 0;
 299 }
 300 
 301 /* RTC layer */
 302 static const struct rtc_class_ops mxc_rtc_ops = {
 303         .read_time              = mxc_rtc_read_time,
 304         .set_time               = mxc_rtc_set_time,
 305         .read_alarm             = mxc_rtc_read_alarm,
 306         .set_alarm              = mxc_rtc_set_alarm,
 307         .alarm_irq_enable       = mxc_rtc_alarm_irq_enable,
 308 };
 309 
 310 static int mxc_rtc_probe(struct platform_device *pdev)
 311 {
 312         struct rtc_device *rtc;
 313         struct rtc_plat_data *pdata = NULL;
 314         u32 reg;
 315         unsigned long rate;
 316         int ret;
 317         const struct of_device_id *of_id;
 318 
 319         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 320         if (!pdata)
 321                 return -ENOMEM;
 322 
 323         of_id = of_match_device(imx_rtc_dt_ids, &pdev->dev);
 324         if (of_id)
 325                 pdata->devtype = (enum imx_rtc_type)of_id->data;
 326         else
 327                 pdata->devtype = pdev->id_entry->driver_data;
 328 
 329         pdata->ioaddr = devm_platform_ioremap_resource(pdev, 0);
 330         if (IS_ERR(pdata->ioaddr))
 331                 return PTR_ERR(pdata->ioaddr);
 332 
 333         rtc = devm_rtc_allocate_device(&pdev->dev);
 334         if (IS_ERR(rtc))
 335                 return PTR_ERR(rtc);
 336 
 337         pdata->rtc = rtc;
 338         rtc->ops = &mxc_rtc_ops;
 339         if (is_imx1_rtc(pdata)) {
 340                 struct rtc_time tm;
 341 
 342                 /* 9bit days + hours minutes seconds */
 343                 rtc->range_max = (1 << 9) * 86400 - 1;
 344 
 345                 /*
 346                  * Set the start date as beginning of the current year. This can
 347                  * be overridden using device tree.
 348                  */
 349                 rtc_time64_to_tm(ktime_get_real_seconds(), &tm);
 350                 rtc->start_secs =  mktime64(tm.tm_year, 1, 1, 0, 0, 0);
 351                 rtc->set_start_time = true;
 352         } else {
 353                 /* 16bit days + hours minutes seconds */
 354                 rtc->range_max = (1 << 16) * 86400ULL - 1;
 355         }
 356 
 357         pdata->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
 358         if (IS_ERR(pdata->clk_ipg)) {
 359                 dev_err(&pdev->dev, "unable to get ipg clock!\n");
 360                 return PTR_ERR(pdata->clk_ipg);
 361         }
 362 
 363         ret = clk_prepare_enable(pdata->clk_ipg);
 364         if (ret)
 365                 return ret;
 366 
 367         pdata->clk_ref = devm_clk_get(&pdev->dev, "ref");
 368         if (IS_ERR(pdata->clk_ref)) {
 369                 dev_err(&pdev->dev, "unable to get ref clock!\n");
 370                 ret = PTR_ERR(pdata->clk_ref);
 371                 goto exit_put_clk_ipg;
 372         }
 373 
 374         ret = clk_prepare_enable(pdata->clk_ref);
 375         if (ret)
 376                 goto exit_put_clk_ipg;
 377 
 378         rate = clk_get_rate(pdata->clk_ref);
 379 
 380         if (rate == 32768)
 381                 reg = RTC_INPUT_CLK_32768HZ;
 382         else if (rate == 32000)
 383                 reg = RTC_INPUT_CLK_32000HZ;
 384         else if (rate == 38400)
 385                 reg = RTC_INPUT_CLK_38400HZ;
 386         else {
 387                 dev_err(&pdev->dev, "rtc clock is not valid (%lu)\n", rate);
 388                 ret = -EINVAL;
 389                 goto exit_put_clk_ref;
 390         }
 391 
 392         reg |= RTC_ENABLE_BIT;
 393         writew(reg, (pdata->ioaddr + RTC_RTCCTL));
 394         if (((readw(pdata->ioaddr + RTC_RTCCTL)) & RTC_ENABLE_BIT) == 0) {
 395                 dev_err(&pdev->dev, "hardware module can't be enabled!\n");
 396                 ret = -EIO;
 397                 goto exit_put_clk_ref;
 398         }
 399 
 400         platform_set_drvdata(pdev, pdata);
 401 
 402         /* Configure and enable the RTC */
 403         pdata->irq = platform_get_irq(pdev, 0);
 404 
 405         if (pdata->irq >= 0 &&
 406             devm_request_irq(&pdev->dev, pdata->irq, mxc_rtc_interrupt,
 407                              IRQF_SHARED, pdev->name, pdev) < 0) {
 408                 dev_warn(&pdev->dev, "interrupt not available.\n");
 409                 pdata->irq = -1;
 410         }
 411 
 412         if (pdata->irq >= 0) {
 413                 device_init_wakeup(&pdev->dev, 1);
 414                 ret = dev_pm_set_wake_irq(&pdev->dev, pdata->irq);
 415                 if (ret)
 416                         dev_err(&pdev->dev, "failed to enable irq wake\n");
 417         }
 418 
 419         ret = rtc_register_device(rtc);
 420         if (ret)
 421                 goto exit_put_clk_ref;
 422 
 423         return 0;
 424 
 425 exit_put_clk_ref:
 426         clk_disable_unprepare(pdata->clk_ref);
 427 exit_put_clk_ipg:
 428         clk_disable_unprepare(pdata->clk_ipg);
 429 
 430         return ret;
 431 }
 432 
 433 static int mxc_rtc_remove(struct platform_device *pdev)
 434 {
 435         struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 436 
 437         clk_disable_unprepare(pdata->clk_ref);
 438         clk_disable_unprepare(pdata->clk_ipg);
 439 
 440         return 0;
 441 }
 442 
 443 static struct platform_driver mxc_rtc_driver = {
 444         .driver = {
 445                    .name        = "mxc_rtc",
 446                    .of_match_table = of_match_ptr(imx_rtc_dt_ids),
 447         },
 448         .id_table = imx_rtc_devtype,
 449         .probe = mxc_rtc_probe,
 450         .remove = mxc_rtc_remove,
 451 };
 452 
 453 module_platform_driver(mxc_rtc_driver)
 454 
 455 MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
 456 MODULE_DESCRIPTION("RTC driver for Freescale MXC");
 457 MODULE_LICENSE("GPL");
 458
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/rtc/rtc-mxc.c

DEFINITIONS
