kernel/drivers/rtc/rtc-rs5c313.c

   1 /*
   2  * Ricoh RS5C313 RTC device/driver
   3  *  Copyright (C) 2007 Nobuhiro Iwamatsu
   4  *
   5  *  2005-09-19 modifed by kogiidena
   6  *
   7  * Based on the old drivers/char/rs5c313_rtc.c  by:
   8  *  Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
   9  *  Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
  10  *
  11  * Based on code written by Paul Gortmaker.
  12  *  Copyright (C) 1996 Paul Gortmaker
  13  *
  14  * This file is subject to the terms and conditions of the GNU General Public
  15  * License.  See the file "COPYING" in the main directory of this archive
  16  * for more details.
  17  *
  18  * Based on other minimal char device drivers, like Alan's
  19  * watchdog, Ted's random, etc. etc.
  20  *
  21  *      1.07    Paul Gortmaker.
  22  *      1.08    Miquel van Smoorenburg: disallow certain things on the
  23  *              DEC Alpha as the CMOS clock is also used for other things.
  24  *      1.09    Nikita Schmidt: epoch support and some Alpha cleanup.
  25  *      1.09a   Pete Zaitcev: Sun SPARC
  26  *      1.09b   Jeff Garzik: Modularize, init cleanup
  27  *      1.09c   Jeff Garzik: SMP cleanup
  28  *      1.10    Paul Barton-Davis: add support for async I/O
  29  *      1.10a   Andrea Arcangeli: Alpha updates
  30  *      1.10b   Andrew Morton: SMP lock fix
  31  *      1.10c   Cesar Barros: SMP locking fixes and cleanup
  32  *      1.10d   Paul Gortmaker: delete paranoia check in rtc_exit
  33  *      1.10e   Maciej W. Rozycki: Handle DECstation's year weirdness.
  34  *      1.11    Takashi Iwai: Kernel access functions
  35  *                            rtc_register/rtc_unregister/rtc_control
  36  *      1.11a   Daniele Bellucci: Audit create_proc_read_entry in rtc_init
  37  *      1.12    Venkatesh Pallipadi: Hooks for emulating rtc on HPET base-timer
  38  *              CONFIG_HPET_EMULATE_RTC
  39  *      1.13    Nobuhiro Iwamatsu: Updata driver.
  40  */
  41
  42 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  43
  44 #include <linux/module.h>
  45 #include <linux/err.h>
  46 #include <linux/rtc.h>
  47 #include <linux/platform_device.h>
  48 #include <linux/bcd.h>
  49 #include <linux/delay.h>
  50 #include <linux/io.h>
  51
  52 #define DRV_NAME        "rs5c313"
  53 #define DRV_VERSION     "1.13"
  54
  55 #ifdef CONFIG_SH_LANDISK
  56 /*****************************************************/
  57 /* LANDISK dependence part of RS5C313                */
  58 /*****************************************************/
  59
  60 #define SCSMR1          0xFFE00000
  61 #define SCSCR1          0xFFE00008
  62 #define SCSMR1_CA       0x80
  63 #define SCSCR1_CKE      0x03
  64 #define SCSPTR1         0xFFE0001C
  65 #define SCSPTR1_EIO     0x80
  66 #define SCSPTR1_SPB1IO  0x08
  67 #define SCSPTR1_SPB1DT  0x04
  68 #define SCSPTR1_SPB0IO  0x02
  69 #define SCSPTR1_SPB0DT  0x01
  70
  71 #define SDA_OEN         SCSPTR1_SPB1IO
  72 #define SDA             SCSPTR1_SPB1DT
  73 #define SCL_OEN         SCSPTR1_SPB0IO
  74 #define SCL             SCSPTR1_SPB0DT
  75
  76 /* RICOH RS5C313 CE port */
  77 #define RS5C313_CE      0xB0000003
  78
  79 /* RICOH RS5C313 CE port bit */
  80 #define RS5C313_CE_RTCCE        0x02
  81
  82 /* SCSPTR1 data */
  83 unsigned char scsptr1_data;
  84
  85 #define RS5C313_CEENABLE    __raw_writeb(RS5C313_CE_RTCCE, RS5C313_CE);
  86 #define RS5C313_CEDISABLE   __raw_writeb(0x00, RS5C313_CE)
  87 #define RS5C313_MISCOP      __raw_writeb(0x02, 0xB0000008)
  88
  89 static void rs5c313_init_port(void)
  90 {
  91         /* Set SCK as I/O port and Initialize SCSPTR1 data & I/O port. */
  92         __raw_writeb(__raw_readb(SCSMR1) & ~SCSMR1_CA, SCSMR1);
  93         __raw_writeb(__raw_readb(SCSCR1) & ~SCSCR1_CKE, SCSCR1);
  94
  95         /* And Initialize SCL for RS5C313 clock */
  96         scsptr1_data = __raw_readb(SCSPTR1) | SCL;      /* SCL:H */
  97         __raw_writeb(scsptr1_data, SCSPTR1);
  98         scsptr1_data = __raw_readb(SCSPTR1) | SCL_OEN;  /* SCL output enable */
  99         __raw_writeb(scsptr1_data, SCSPTR1);
 100         RS5C313_CEDISABLE;      /* CE:L */
 101 }
 102
 103 static void rs5c313_write_data(unsigned char data)
 104 {
 105         int i;
 106
 107         for (i = 0; i < 8; i++) {
 108                 /* SDA:Write Data */
 109                 scsptr1_data = (scsptr1_data & ~SDA) |
 110                                 ((((0x80 >> i) & data) >> (7 - i)) << 2);
 111                 __raw_writeb(scsptr1_data, SCSPTR1);
 112                 if (i == 0) {
 113                         scsptr1_data |= SDA_OEN;        /* SDA:output enable */
 114                         __raw_writeb(scsptr1_data, SCSPTR1);
 115                 }
 116                 ndelay(700);
 117                 scsptr1_data &= ~SCL;   /* SCL:L */
 118                 __raw_writeb(scsptr1_data, SCSPTR1);
 119                 ndelay(700);
 120                 scsptr1_data |= SCL;    /* SCL:H */
 121                 __raw_writeb(scsptr1_data, SCSPTR1);
 122         }
 123
 124         scsptr1_data &= ~SDA_OEN;       /* SDA:output disable */
 125         __raw_writeb(scsptr1_data, SCSPTR1);
 126 }
 127
 128 static unsigned char rs5c313_read_data(void)
 129 {
 130         int i;
 131         unsigned char data = 0;
 132
 133         for (i = 0; i < 8; i++) {
 134                 ndelay(700);
 135                 /* SDA:Read Data */
 136                 data |= ((__raw_readb(SCSPTR1) & SDA) >> 2) << (7 - i);
 137                 scsptr1_data &= ~SCL;   /* SCL:L */
 138                 __raw_writeb(scsptr1_data, SCSPTR1);
 139                 ndelay(700);
 140                 scsptr1_data |= SCL;    /* SCL:H */
 141                 __raw_writeb(scsptr1_data, SCSPTR1);
 142         }
 143         return data & 0x0F;
 144 }
 145
 146 #endif /* CONFIG_SH_LANDISK */
 147
 148 /*****************************************************/
 149 /* machine independence part of RS5C313              */
 150 /*****************************************************/
 151
 152 /* RICOH RS5C313 address */
 153 #define RS5C313_ADDR_SEC        0x00
 154 #define RS5C313_ADDR_SEC10      0x01
 155 #define RS5C313_ADDR_MIN        0x02
 156 #define RS5C313_ADDR_MIN10      0x03
 157 #define RS5C313_ADDR_HOUR       0x04
 158 #define RS5C313_ADDR_HOUR10     0x05
 159 #define RS5C313_ADDR_WEEK       0x06
 160 #define RS5C313_ADDR_INTINTVREG 0x07
 161 #define RS5C313_ADDR_DAY        0x08
 162 #define RS5C313_ADDR_DAY10      0x09
 163 #define RS5C313_ADDR_MON        0x0A
 164 #define RS5C313_ADDR_MON10      0x0B
 165 #define RS5C313_ADDR_YEAR       0x0C
 166 #define RS5C313_ADDR_YEAR10     0x0D
 167 #define RS5C313_ADDR_CNTREG     0x0E
 168 #define RS5C313_ADDR_TESTREG    0x0F
 169
 170 /* RICOH RS5C313 control register */
 171 #define RS5C313_CNTREG_ADJ_BSY  0x01
 172 #define RS5C313_CNTREG_WTEN_XSTP        0x02
 173 #define RS5C313_CNTREG_12_24    0x04
 174 #define RS5C313_CNTREG_CTFG     0x08
 175
 176 /* RICOH RS5C313 test register */
 177 #define RS5C313_TESTREG_TEST    0x01
 178
 179 /* RICOH RS5C313 control bit */
 180 #define RS5C313_CNTBIT_READ     0x40
 181 #define RS5C313_CNTBIT_AD       0x20
 182 #define RS5C313_CNTBIT_DT       0x10
 183
 184 static unsigned char rs5c313_read_reg(unsigned char addr)
 185 {
 186
 187         rs5c313_write_data(addr | RS5C313_CNTBIT_READ | RS5C313_CNTBIT_AD);
 188         return rs5c313_read_data();
 189 }
 190
 191 static void rs5c313_write_reg(unsigned char addr, unsigned char data)
 192 {
 193         data &= 0x0f;
 194         rs5c313_write_data(addr | RS5C313_CNTBIT_AD);
 195         rs5c313_write_data(data | RS5C313_CNTBIT_DT);
 196         return;
 197 }
 198
 199 static inline unsigned char rs5c313_read_cntreg(void)
 200 {
 201         return rs5c313_read_reg(RS5C313_ADDR_CNTREG);
 202 }
 203
 204 static inline void rs5c313_write_cntreg(unsigned char data)
 205 {
 206         rs5c313_write_reg(RS5C313_ADDR_CNTREG, data);
 207 }
 208
 209 static inline void rs5c313_write_intintvreg(unsigned char data)
 210 {
 211         rs5c313_write_reg(RS5C313_ADDR_INTINTVREG, data);
 212 }
 213
 214 static int rs5c313_rtc_read_time(struct device *dev, struct rtc_time *tm)
 215 {
 216         int data;
 217         int cnt;
 218
 219         cnt = 0;
 220         while (1) {
 221                 RS5C313_CEENABLE;       /* CE:H */
 222
 223                 /* Initialize control reg. 24 hour */
 224                 rs5c313_write_cntreg(0x04);
 225
 226                 if (!(rs5c313_read_cntreg() & RS5C313_CNTREG_ADJ_BSY))
 227                         break;
 228
 229                 RS5C313_CEDISABLE;
 230                 ndelay(700);    /* CE:L */
 231
 232                 if (cnt++ > 100) {
 233                         dev_err(dev, "%s: timeout error\n", __func__);
 234                         return -EIO;
 235                 }
 236         }
 237
 238         data = rs5c313_read_reg(RS5C313_ADDR_SEC);
 239         data |= (rs5c313_read_reg(RS5C313_ADDR_SEC10) << 4);
 240         tm->tm_sec = bcd2bin(data);
 241
 242         data = rs5c313_read_reg(RS5C313_ADDR_MIN);
 243         data |= (rs5c313_read_reg(RS5C313_ADDR_MIN10) << 4);
 244         tm->tm_min = bcd2bin(data);
 245
 246         data = rs5c313_read_reg(RS5C313_ADDR_HOUR);
 247         data |= (rs5c313_read_reg(RS5C313_ADDR_HOUR10) << 4);
 248         tm->tm_hour = bcd2bin(data);
 249
 250         data = rs5c313_read_reg(RS5C313_ADDR_DAY);
 251         data |= (rs5c313_read_reg(RS5C313_ADDR_DAY10) << 4);
 252         tm->tm_mday = bcd2bin(data);
 253
 254         data = rs5c313_read_reg(RS5C313_ADDR_MON);
 255         data |= (rs5c313_read_reg(RS5C313_ADDR_MON10) << 4);
 256         tm->tm_mon = bcd2bin(data) - 1;
 257
 258         data = rs5c313_read_reg(RS5C313_ADDR_YEAR);
 259         data |= (rs5c313_read_reg(RS5C313_ADDR_YEAR10) << 4);
 260         tm->tm_year = bcd2bin(data);
 261
 262         if (tm->tm_year < 70)
 263                 tm->tm_year += 100;
 264
 265         data = rs5c313_read_reg(RS5C313_ADDR_WEEK);
 266         tm->tm_wday = bcd2bin(data);
 267
 268         RS5C313_CEDISABLE;
 269         ndelay(700);            /* CE:L */
 270
 271         return 0;
 272 }
 273
 274 static int rs5c313_rtc_set_time(struct device *dev, struct rtc_time *tm)
 275 {
 276         int data;
 277         int cnt;
 278
 279         cnt = 0;
 280         /* busy check. */
 281         while (1) {
 282                 RS5C313_CEENABLE;       /* CE:H */
 283
 284                 /* Initiatlize control reg. 24 hour */
 285                 rs5c313_write_cntreg(0x04);
 286
 287                 if (!(rs5c313_read_cntreg() & RS5C313_CNTREG_ADJ_BSY))
 288                         break;
 289                 RS5C313_MISCOP;
 290                 RS5C313_CEDISABLE;
 291                 ndelay(700);    /* CE:L */
 292
 293                 if (cnt++ > 100) {
 294                         dev_err(dev, "%s: timeout error\n", __func__);
 295                         return -EIO;
 296                 }
 297         }
 298
 299         data = bin2bcd(tm->tm_sec);
 300         rs5c313_write_reg(RS5C313_ADDR_SEC, data);
 301         rs5c313_write_reg(RS5C313_ADDR_SEC10, (data >> 4));
 302
 303         data = bin2bcd(tm->tm_min);
 304         rs5c313_write_reg(RS5C313_ADDR_MIN, data);
 305         rs5c313_write_reg(RS5C313_ADDR_MIN10, (data >> 4));
 306
 307         data = bin2bcd(tm->tm_hour);
 308         rs5c313_write_reg(RS5C313_ADDR_HOUR, data);
 309         rs5c313_write_reg(RS5C313_ADDR_HOUR10, (data >> 4));
 310
 311         data = bin2bcd(tm->tm_mday);
 312         rs5c313_write_reg(RS5C313_ADDR_DAY, data);
 313         rs5c313_write_reg(RS5C313_ADDR_DAY10, (data >> 4));
 314
 315         data = bin2bcd(tm->tm_mon + 1);
 316         rs5c313_write_reg(RS5C313_ADDR_MON, data);
 317         rs5c313_write_reg(RS5C313_ADDR_MON10, (data >> 4));
 318
 319         data = bin2bcd(tm->tm_year % 100);
 320         rs5c313_write_reg(RS5C313_ADDR_YEAR, data);
 321         rs5c313_write_reg(RS5C313_ADDR_YEAR10, (data >> 4));
 322
 323         data = bin2bcd(tm->tm_wday);
 324         rs5c313_write_reg(RS5C313_ADDR_WEEK, data);
 325
 326         RS5C313_CEDISABLE;      /* CE:H */
 327         ndelay(700);
 328
 329         return 0;
 330 }
 331
 332 static void rs5c313_check_xstp_bit(void)
 333 {
 334         struct rtc_time tm;
 335         int cnt;
 336
 337         RS5C313_CEENABLE;       /* CE:H */
 338         if (rs5c313_read_cntreg() & RS5C313_CNTREG_WTEN_XSTP) {
 339                 /* INT interval reg. OFF */
 340                 rs5c313_write_intintvreg(0x00);
 341                 /* Initialize control reg. 24 hour & adjust */
 342                 rs5c313_write_cntreg(0x07);
 343
 344                 /* busy check. */
 345                 for (cnt = 0; cnt < 100; cnt++) {
 346                         if (!(rs5c313_read_cntreg() & RS5C313_CNTREG_ADJ_BSY))
 347                                 break;
 348                         RS5C313_MISCOP;
 349                 }
 350
 351                 memset(&tm, 0, sizeof(struct rtc_time));
 352                 tm.tm_mday      = 1;
 353                 tm.tm_mon       = 1 - 1;
 354                 tm.tm_year      = 2000 - 1900;
 355
 356                 rs5c313_rtc_set_time(NULL, &tm);
 357                 pr_err("invalid value, resetting to 1 Jan 2000\n");
 358         }
 359         RS5C313_CEDISABLE;
 360         ndelay(700);            /* CE:L */
 361 }
 362
 363 static const struct rtc_class_ops rs5c313_rtc_ops = {
 364         .read_time = rs5c313_rtc_read_time,
 365         .set_time = rs5c313_rtc_set_time,
 366 };
 367
 368 static int rs5c313_rtc_probe(struct platform_device *pdev)
 369 {
 370         struct rtc_device *rtc = devm_rtc_device_register(&pdev->dev, "rs5c313",
 371                                 &rs5c313_rtc_ops, THIS_MODULE);
 372
 373         if (IS_ERR(rtc))
 374                 return PTR_ERR(rtc);
 375
 376         platform_set_drvdata(pdev, rtc);
 377
 378         return 0;
 379 }
 380
 381 static struct platform_driver rs5c313_rtc_platform_driver = {
 382         .driver         = {
 383                 .name   = DRV_NAME,
 384         },
 385         .probe  = rs5c313_rtc_probe,
 386 };
 387
 388 static int __init rs5c313_rtc_init(void)
 389 {
 390         int err;
 391
 392         err = platform_driver_register(&rs5c313_rtc_platform_driver);
 393         if (err)
 394                 return err;
 395
 396         rs5c313_init_port();
 397         rs5c313_check_xstp_bit();
 398
 399         return 0;
 400 }
 401
 402 static void __exit rs5c313_rtc_exit(void)
 403 {
 404         platform_driver_unregister(&rs5c313_rtc_platform_driver);
 405 }
 406
 407 module_init(rs5c313_rtc_init);
 408 module_exit(rs5c313_rtc_exit);
 409
 410 MODULE_VERSION(DRV_VERSION);
 411 MODULE_AUTHOR("kogiidena , Nobuhiro Iwamatsu <iwamatsu@nigauri.org>");
 412 MODULE_DESCRIPTION("Ricoh RS5C313 RTC device driver");
 413 MODULE_LICENSE("GPL");
 414 MODULE_ALIAS("platform:" DRV_NAME);