drivers/rtc/rtc-rs5c313.c

   1 /*
   2  * Ricoh RS5C313 RTC device/driver
   3  *  Copyright (C) 2007 Nobuhiro Iwamatsu
   4  *
   5  *  2005-09-19 modified 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: Update 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
  54 #ifdef CONFIG_SH_LANDISK
  55 /*****************************************************/
  56 /* LANDISK dependence part of RS5C313                */
  57 /*****************************************************/
  58
  59 #define SCSMR1          0xFFE00000
  60 #define SCSCR1          0xFFE00008
  61 #define SCSMR1_CA       0x80
  62 #define SCSCR1_CKE      0x03
  63 #define SCSPTR1         0xFFE0001C
  64 #define SCSPTR1_EIO     0x80
  65 #define SCSPTR1_SPB1IO  0x08
  66 #define SCSPTR1_SPB1DT  0x04
  67 #define SCSPTR1_SPB0IO  0x02
  68 #define SCSPTR1_SPB0DT  0x01
  69
  70 #define SDA_OEN         SCSPTR1_SPB1IO
  71 #define SDA             SCSPTR1_SPB1DT
  72 #define SCL_OEN         SCSPTR1_SPB0IO
  73 #define SCL             SCSPTR1_SPB0DT
  74
  75 /* RICOH RS5C313 CE port */
  76 #define RS5C313_CE      0xB0000003
  77
  78 /* RICOH RS5C313 CE port bit */
  79 #define RS5C313_CE_RTCCE        0x02
  80
  81 /* SCSPTR1 data */
  82 unsigned char scsptr1_data;
  83
  84 #define RS5C313_CEENABLE    __raw_writeb(RS5C313_CE_RTCCE, RS5C313_CE);
  85 #define RS5C313_CEDISABLE   __raw_writeb(0x00, RS5C313_CE)
  86 #define RS5C313_MISCOP      __raw_writeb(0x02, 0xB0000008)
  87
  88 static void rs5c313_init_port(void)
  89 {
  90         /* Set SCK as I/O port and Initialize SCSPTR1 data & I/O port. */
  91         __raw_writeb(__raw_readb(SCSMR1) & ~SCSMR1_CA, SCSMR1);
  92         __raw_writeb(__raw_readb(SCSCR1) & ~SCSCR1_CKE, SCSCR1);
  93
  94         /* And Initialize SCL for RS5C313 clock */
  95         scsptr1_data = __raw_readb(SCSPTR1) | SCL;      /* SCL:H */
  96         __raw_writeb(scsptr1_data, SCSPTR1);
  97         scsptr1_data = __raw_readb(SCSPTR1) | SCL_OEN;  /* SCL output enable */
  98         __raw_writeb(scsptr1_data, SCSPTR1);
  99         RS5C313_CEDISABLE;      /* CE:L */
 100 }
 101
 102 static void rs5c313_write_data(unsigned char data)
 103 {
 104         int i;
 105
 106         for (i = 0; i < 8; i++) {
 107                 /* SDA:Write Data */
 108                 scsptr1_data = (scsptr1_data & ~SDA) |
 109                                 ((((0x80 >> i) & data) >> (7 - i)) << 2);
 110                 __raw_writeb(scsptr1_data, SCSPTR1);
 111                 if (i == 0) {
 112                         scsptr1_data |= SDA_OEN;        /* SDA:output enable */
 113                         __raw_writeb(scsptr1_data, SCSPTR1);
 114                 }
 115                 ndelay(700);
 116                 scsptr1_data &= ~SCL;   /* SCL:L */
 117                 __raw_writeb(scsptr1_data, SCSPTR1);
 118                 ndelay(700);
 119                 scsptr1_data |= SCL;    /* SCL:H */
 120                 __raw_writeb(scsptr1_data, SCSPTR1);
 121         }
 122
 123         scsptr1_data &= ~SDA_OEN;       /* SDA:output disable */
 124         __raw_writeb(scsptr1_data, SCSPTR1);
 125 }
 126
 127 static unsigned char rs5c313_read_data(void)
 128 {
 129         int i;
 130         unsigned char data = 0;
 131
 132         for (i = 0; i < 8; i++) {
 133                 ndelay(700);
 134                 /* SDA:Read Data */
 135                 data |= ((__raw_readb(SCSPTR1) & SDA) >> 2) << (7 - i);
 136                 scsptr1_data &= ~SCL;   /* SCL:L */
 137                 __raw_writeb(scsptr1_data, SCSPTR1);
 138                 ndelay(700);
 139                 scsptr1_data |= SCL;    /* SCL:H */
 140                 __raw_writeb(scsptr1_data, SCSPTR1);
 141         }
 142         return data & 0x0F;
 143 }
 144
 145 #endif /* CONFIG_SH_LANDISK */
 146
 147 /*****************************************************/
 148 /* machine independence part of RS5C313              */
 149 /*****************************************************/
 150
 151 /* RICOH RS5C313 address */
 152 #define RS5C313_ADDR_SEC        0x00
 153 #define RS5C313_ADDR_SEC10      0x01
 154 #define RS5C313_ADDR_MIN        0x02
 155 #define RS5C313_ADDR_MIN10      0x03
 156 #define RS5C313_ADDR_HOUR       0x04
 157 #define RS5C313_ADDR_HOUR10     0x05
 158 #define RS5C313_ADDR_WEEK       0x06
 159 #define RS5C313_ADDR_INTINTVREG 0x07
 160 #define RS5C313_ADDR_DAY        0x08
 161 #define RS5C313_ADDR_DAY10      0x09
 162 #define RS5C313_ADDR_MON        0x0A
 163 #define RS5C313_ADDR_MON10      0x0B
 164 #define RS5C313_ADDR_YEAR       0x0C
 165 #define RS5C313_ADDR_YEAR10     0x0D
 166 #define RS5C313_ADDR_CNTREG     0x0E
 167 #define RS5C313_ADDR_TESTREG    0x0F
 168
 169 /* RICOH RS5C313 control register */
 170 #define RS5C313_CNTREG_ADJ_BSY  0x01
 171 #define RS5C313_CNTREG_WTEN_XSTP        0x02
 172 #define RS5C313_CNTREG_12_24    0x04
 173 #define RS5C313_CNTREG_CTFG     0x08
 174
 175 /* RICOH RS5C313 test register */
 176 #define RS5C313_TESTREG_TEST    0x01
 177
 178 /* RICOH RS5C313 control bit */
 179 #define RS5C313_CNTBIT_READ     0x40
 180 #define RS5C313_CNTBIT_AD       0x20
 181 #define RS5C313_CNTBIT_DT       0x10
 182
 183 static unsigned char rs5c313_read_reg(unsigned char addr)
 184 {
 185
 186         rs5c313_write_data(addr | RS5C313_CNTBIT_READ | RS5C313_CNTBIT_AD);
 187         return rs5c313_read_data();
 188 }
 189
 190 static void rs5c313_write_reg(unsigned char addr, unsigned char data)
 191 {
 192         data &= 0x0f;
 193         rs5c313_write_data(addr | RS5C313_CNTBIT_AD);
 194         rs5c313_write_data(data | RS5C313_CNTBIT_DT);
 195         return;
 196 }
 197
 198 static inline unsigned char rs5c313_read_cntreg(void)
 199 {
 200         return rs5c313_read_reg(RS5C313_ADDR_CNTREG);
 201 }
 202
 203 static inline void rs5c313_write_cntreg(unsigned char data)
 204 {
 205         rs5c313_write_reg(RS5C313_ADDR_CNTREG, data);
 206 }
 207
 208 static inline void rs5c313_write_intintvreg(unsigned char data)
 209 {
 210         rs5c313_write_reg(RS5C313_ADDR_INTINTVREG, data);
 211 }
 212
 213 static int rs5c313_rtc_read_time(struct device *dev, struct rtc_time *tm)
 214 {
 215         int data;
 216         int cnt;
 217
 218         cnt = 0;
 219         while (1) {
 220                 RS5C313_CEENABLE;       /* CE:H */
 221
 222                 /* Initialize control reg. 24 hour */
 223                 rs5c313_write_cntreg(0x04);
 224
 225                 if (!(rs5c313_read_cntreg() & RS5C313_CNTREG_ADJ_BSY))
 226                         break;
 227
 228                 RS5C313_CEDISABLE;
 229                 ndelay(700);    /* CE:L */
 230
 231                 if (cnt++ > 100) {
 232                         dev_err(dev, "%s: timeout error\n", __func__);
 233                         return -EIO;
 234                 }
 235         }
 236
 237         data = rs5c313_read_reg(RS5C313_ADDR_SEC);
 238         data |= (rs5c313_read_reg(RS5C313_ADDR_SEC10) << 4);
 239         tm->tm_sec = bcd2bin(data);
 240
 241         data = rs5c313_read_reg(RS5C313_ADDR_MIN);
 242         data |= (rs5c313_read_reg(RS5C313_ADDR_MIN10) << 4);
 243         tm->tm_min = bcd2bin(data);
 244
 245         data = rs5c313_read_reg(RS5C313_ADDR_HOUR);
 246         data |= (rs5c313_read_reg(RS5C313_ADDR_HOUR10) << 4);
 247         tm->tm_hour = bcd2bin(data);
 248
 249         data = rs5c313_read_reg(RS5C313_ADDR_DAY);
 250         data |= (rs5c313_read_reg(RS5C313_ADDR_DAY10) << 4);
 251         tm->tm_mday = bcd2bin(data);
 252
 253         data = rs5c313_read_reg(RS5C313_ADDR_MON);
 254         data |= (rs5c313_read_reg(RS5C313_ADDR_MON10) << 4);
 255         tm->tm_mon = bcd2bin(data) - 1;
 256
 257         data = rs5c313_read_reg(RS5C313_ADDR_YEAR);
 258         data |= (rs5c313_read_reg(RS5C313_ADDR_YEAR10) << 4);
 259         tm->tm_year = bcd2bin(data);
 260
 261         if (tm->tm_year < 70)
 262                 tm->tm_year += 100;
 263
 264         data = rs5c313_read_reg(RS5C313_ADDR_WEEK);
 265         tm->tm_wday = bcd2bin(data);
 266
 267         RS5C313_CEDISABLE;
 268         ndelay(700);            /* CE:L */
 269
 270         return 0;
 271 }
 272
 273 static int rs5c313_rtc_set_time(struct device *dev, struct rtc_time *tm)
 274 {
 275         int data;
 276         int cnt;
 277
 278         cnt = 0;
 279         /* busy check. */
 280         while (1) {
 281                 RS5C313_CEENABLE;       /* CE:H */
 282
 283                 /* Initialize control reg. 24 hour */
 284                 rs5c313_write_cntreg(0x04);
 285
 286                 if (!(rs5c313_read_cntreg() & RS5C313_CNTREG_ADJ_BSY))
 287                         break;
 288                 RS5C313_MISCOP;
 289                 RS5C313_CEDISABLE;
 290                 ndelay(700);    /* CE:L */
 291
 292                 if (cnt++ > 100) {
 293                         dev_err(dev, "%s: timeout error\n", __func__);
 294                         return -EIO;
 295                 }
 296         }
 297
 298         data = bin2bcd(tm->tm_sec);
 299         rs5c313_write_reg(RS5C313_ADDR_SEC, data);
 300         rs5c313_write_reg(RS5C313_ADDR_SEC10, (data >> 4));
 301
 302         data = bin2bcd(tm->tm_min);
 303         rs5c313_write_reg(RS5C313_ADDR_MIN, data);
 304         rs5c313_write_reg(RS5C313_ADDR_MIN10, (data >> 4));
 305
 306         data = bin2bcd(tm->tm_hour);
 307         rs5c313_write_reg(RS5C313_ADDR_HOUR, data);
 308         rs5c313_write_reg(RS5C313_ADDR_HOUR10, (data >> 4));
 309
 310         data = bin2bcd(tm->tm_mday);
 311         rs5c313_write_reg(RS5C313_ADDR_DAY, data);
 312         rs5c313_write_reg(RS5C313_ADDR_DAY10, (data >> 4));
 313
 314         data = bin2bcd(tm->tm_mon + 1);
 315         rs5c313_write_reg(RS5C313_ADDR_MON, data);
 316         rs5c313_write_reg(RS5C313_ADDR_MON10, (data >> 4));
 317
 318         data = bin2bcd(tm->tm_year % 100);
 319         rs5c313_write_reg(RS5C313_ADDR_YEAR, data);
 320         rs5c313_write_reg(RS5C313_ADDR_YEAR10, (data >> 4));
 321
 322         data = bin2bcd(tm->tm_wday);
 323         rs5c313_write_reg(RS5C313_ADDR_WEEK, data);
 324
 325         RS5C313_CEDISABLE;      /* CE:H */
 326         ndelay(700);
 327
 328         return 0;
 329 }
 330
 331 static void rs5c313_check_xstp_bit(void)
 332 {
 333         struct rtc_time tm;
 334         int cnt;
 335
 336         RS5C313_CEENABLE;       /* CE:H */
 337         if (rs5c313_read_cntreg() & RS5C313_CNTREG_WTEN_XSTP) {
 338                 /* INT interval reg. OFF */
 339                 rs5c313_write_intintvreg(0x00);
 340                 /* Initialize control reg. 24 hour & adjust */
 341                 rs5c313_write_cntreg(0x07);
 342
 343                 /* busy check. */
 344                 for (cnt = 0; cnt < 100; cnt++) {
 345                         if (!(rs5c313_read_cntreg() & RS5C313_CNTREG_ADJ_BSY))
 346                                 break;
 347                         RS5C313_MISCOP;
 348                 }
 349
 350                 memset(&tm, 0, sizeof(struct rtc_time));
 351                 tm.tm_mday      = 1;
 352                 tm.tm_mon       = 1 - 1;
 353                 tm.tm_year      = 2000 - 1900;
 354
 355                 rs5c313_rtc_set_time(NULL, &tm);
 356                 pr_err("invalid value, resetting to 1 Jan 2000\n");
 357         }
 358         RS5C313_CEDISABLE;
 359         ndelay(700);            /* CE:L */
 360 }
 361
 362 static const struct rtc_class_ops rs5c313_rtc_ops = {
 363         .read_time = rs5c313_rtc_read_time,
 364         .set_time = rs5c313_rtc_set_time,
 365 };
 366
 367 static int rs5c313_rtc_probe(struct platform_device *pdev)
 368 {
 369         struct rtc_device *rtc;
 370
 371         rs5c313_init_port();
 372         rs5c313_check_xstp_bit();
 373
 374         rtc = devm_rtc_device_register(&pdev->dev, "rs5c313", &rs5c313_rtc_ops,
 375                                        THIS_MODULE);
 376
 377         return PTR_ERR_OR_ZERO(rtc);
 378 }
 379
 380 static struct platform_driver rs5c313_rtc_platform_driver = {
 381         .driver         = {
 382                 .name   = DRV_NAME,
 383         },
 384         .probe  = rs5c313_rtc_probe,
 385 };
 386
 387 module_platform_driver(rs5c313_rtc_platform_driver);
 388
 389 MODULE_AUTHOR("kogiidena , Nobuhiro Iwamatsu <iwamatsu@nigauri.org>");
 390 MODULE_DESCRIPTION("Ricoh RS5C313 RTC device driver");
 391 MODULE_LICENSE("GPL");
 392 MODULE_ALIAS("platform:" DRV_NAME);