linux/drivers/input/misc/hp_sdc_rtc.c
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   1/*
   2 * HP i8042 SDC + MSM-58321 BBRTC driver.
   3 *
   4 * Copyright (c) 2001 Brian S. Julin
   5 * All rights reserved.
   6 *
   7 * Redistribution and use in source and binary forms, with or without
   8 * modification, are permitted provided that the following conditions
   9 * are met:
  10 * 1. Redistributions of source code must retain the above copyright
  11 *    notice, this list of conditions, and the following disclaimer,
  12 *    without modification.
  13 * 2. The name of the author may not be used to endorse or promote products
  14 *    derived from this software without specific prior written permission.
  15 *
  16 * Alternatively, this software may be distributed under the terms of the
  17 * GNU General Public License ("GPL").
  18 *
  19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  23 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28 *
  29 * References:
  30 * System Device Controller Microprocessor Firmware Theory of Operation
  31 *      for Part Number 1820-4784 Revision B.  Dwg No. A-1820-4784-2
  32 * efirtc.c by Stephane Eranian/Hewlett Packard
  33 *
  34 */
  35
  36#include <linux/hp_sdc.h>
  37#include <linux/errno.h>
  38#include <linux/types.h>
  39#include <linux/init.h>
  40#include <linux/module.h>
  41#include <linux/time.h>
  42#include <linux/miscdevice.h>
  43#include <linux/proc_fs.h>
  44#include <linux/seq_file.h>
  45#include <linux/poll.h>
  46#include <linux/rtc.h>
  47#include <linux/mutex.h>
  48#include <linux/semaphore.h>
  49
  50MODULE_AUTHOR("Brian S. Julin <bri@calyx.com>");
  51MODULE_DESCRIPTION("HP i8042 SDC + MSM-58321 RTC Driver");
  52MODULE_LICENSE("Dual BSD/GPL");
  53
  54#define RTC_VERSION "1.10d"
  55
  56static unsigned long epoch = 2000;
  57
  58static struct semaphore i8042tregs;
  59
  60static void hp_sdc_rtc_isr (int irq, void *dev_id, 
  61                            uint8_t status, uint8_t data) 
  62{
  63        return;
  64}
  65
  66static int hp_sdc_rtc_do_read_bbrtc (struct rtc_time *rtctm)
  67{
  68        struct semaphore tsem;
  69        hp_sdc_transaction t;
  70        uint8_t tseq[91];
  71        int i;
  72        
  73        i = 0;
  74        while (i < 91) {
  75                tseq[i++] = HP_SDC_ACT_DATAREG |
  76                        HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN;
  77                tseq[i++] = 0x01;                       /* write i8042[0x70] */
  78                tseq[i]   = i / 7;                      /* BBRTC reg address */
  79                i++;
  80                tseq[i++] = HP_SDC_CMD_DO_RTCR;         /* Trigger command   */
  81                tseq[i++] = 2;          /* expect 1 stat/dat pair back.   */
  82                i++; i++;               /* buffer for stat/dat pair       */
  83        }
  84        tseq[84] |= HP_SDC_ACT_SEMAPHORE;
  85        t.endidx =              91;
  86        t.seq =                 tseq;
  87        t.act.semaphore =       &tsem;
  88        sema_init(&tsem, 0);
  89        
  90        if (hp_sdc_enqueue_transaction(&t)) return -1;
  91        
  92        /* Put ourselves to sleep for results. */
  93        if (WARN_ON(down_interruptible(&tsem)))
  94                return -1;
  95        
  96        /* Check for nonpresence of BBRTC */
  97        if (!((tseq[83] | tseq[90] | tseq[69] | tseq[76] |
  98               tseq[55] | tseq[62] | tseq[34] | tseq[41] |
  99               tseq[20] | tseq[27] | tseq[6]  | tseq[13]) & 0x0f))
 100                return -1;
 101
 102        memset(rtctm, 0, sizeof(struct rtc_time));
 103        rtctm->tm_year = (tseq[83] & 0x0f) + (tseq[90] & 0x0f) * 10;
 104        rtctm->tm_mon  = (tseq[69] & 0x0f) + (tseq[76] & 0x0f) * 10;
 105        rtctm->tm_mday = (tseq[55] & 0x0f) + (tseq[62] & 0x0f) * 10;
 106        rtctm->tm_wday = (tseq[48] & 0x0f);
 107        rtctm->tm_hour = (tseq[34] & 0x0f) + (tseq[41] & 0x0f) * 10;
 108        rtctm->tm_min  = (tseq[20] & 0x0f) + (tseq[27] & 0x0f) * 10;
 109        rtctm->tm_sec  = (tseq[6]  & 0x0f) + (tseq[13] & 0x0f) * 10;
 110        
 111        return 0;
 112}
 113
 114static int hp_sdc_rtc_read_bbrtc (struct rtc_time *rtctm)
 115{
 116        struct rtc_time tm, tm_last;
 117        int i = 0;
 118
 119        /* MSM-58321 has no read latch, so must read twice and compare. */
 120
 121        if (hp_sdc_rtc_do_read_bbrtc(&tm_last)) return -1;
 122        if (hp_sdc_rtc_do_read_bbrtc(&tm)) return -1;
 123
 124        while (memcmp(&tm, &tm_last, sizeof(struct rtc_time))) {
 125                if (i++ > 4) return -1;
 126                memcpy(&tm_last, &tm, sizeof(struct rtc_time));
 127                if (hp_sdc_rtc_do_read_bbrtc(&tm)) return -1;
 128        }
 129
 130        memcpy(rtctm, &tm, sizeof(struct rtc_time));
 131
 132        return 0;
 133}
 134
 135
 136static int64_t hp_sdc_rtc_read_i8042timer (uint8_t loadcmd, int numreg)
 137{
 138        hp_sdc_transaction t;
 139        uint8_t tseq[26] = {
 140                HP_SDC_ACT_PRECMD | HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN,
 141                0,
 142                HP_SDC_CMD_READ_T1, 2, 0, 0,
 143                HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN, 
 144                HP_SDC_CMD_READ_T2, 2, 0, 0,
 145                HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN, 
 146                HP_SDC_CMD_READ_T3, 2, 0, 0,
 147                HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN, 
 148                HP_SDC_CMD_READ_T4, 2, 0, 0,
 149                HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN, 
 150                HP_SDC_CMD_READ_T5, 2, 0, 0
 151        };
 152
 153        t.endidx = numreg * 5;
 154
 155        tseq[1] = loadcmd;
 156        tseq[t.endidx - 4] |= HP_SDC_ACT_SEMAPHORE; /* numreg assumed > 1 */
 157
 158        t.seq =                 tseq;
 159        t.act.semaphore =       &i8042tregs;
 160
 161        /* Sleep if output regs in use. */
 162        if (WARN_ON(down_interruptible(&i8042tregs)))
 163                return -1;
 164
 165        if (hp_sdc_enqueue_transaction(&t)) {
 166                up(&i8042tregs);
 167                return -1;
 168        }
 169        
 170        /* Sleep until results come back. */
 171        if (WARN_ON(down_interruptible(&i8042tregs)))
 172                return -1;
 173
 174        up(&i8042tregs);
 175
 176        return (tseq[5] | 
 177                ((uint64_t)(tseq[10]) << 8)  | ((uint64_t)(tseq[15]) << 16) |
 178                ((uint64_t)(tseq[20]) << 24) | ((uint64_t)(tseq[25]) << 32));
 179}
 180
 181
 182/* Read the i8042 real-time clock */
 183static inline int hp_sdc_rtc_read_rt(struct timespec64 *res) {
 184        int64_t raw;
 185        uint32_t tenms; 
 186        unsigned int days;
 187
 188        raw = hp_sdc_rtc_read_i8042timer(HP_SDC_CMD_LOAD_RT, 5);
 189        if (raw < 0) return -1;
 190
 191        tenms = (uint32_t)raw & 0xffffff;
 192        days  = (unsigned int)(raw >> 24) & 0xffff;
 193
 194        res->tv_nsec = (long)(tenms % 100) * 10000 * 1000;
 195        res->tv_sec =  (tenms / 100) + (time64_t)days * 86400;
 196
 197        return 0;
 198}
 199
 200
 201/* Read the i8042 fast handshake timer */
 202static inline int hp_sdc_rtc_read_fhs(struct timespec64 *res) {
 203        int64_t raw;
 204        unsigned int tenms;
 205
 206        raw = hp_sdc_rtc_read_i8042timer(HP_SDC_CMD_LOAD_FHS, 2);
 207        if (raw < 0) return -1;
 208
 209        tenms = (unsigned int)raw & 0xffff;
 210
 211        res->tv_nsec = (long)(tenms % 100) * 10000 * 1000;
 212        res->tv_sec  = (time64_t)(tenms / 100);
 213
 214        return 0;
 215}
 216
 217
 218/* Read the i8042 match timer (a.k.a. alarm) */
 219static inline int hp_sdc_rtc_read_mt(struct timespec64 *res) {
 220        int64_t raw;    
 221        uint32_t tenms; 
 222
 223        raw = hp_sdc_rtc_read_i8042timer(HP_SDC_CMD_LOAD_MT, 3);
 224        if (raw < 0) return -1;
 225
 226        tenms = (uint32_t)raw & 0xffffff;
 227
 228        res->tv_nsec = (long)(tenms % 100) * 10000 * 1000;
 229        res->tv_sec  = (time64_t)(tenms / 100);
 230
 231        return 0;
 232}
 233
 234
 235/* Read the i8042 delay timer */
 236static inline int hp_sdc_rtc_read_dt(struct timespec64 *res) {
 237        int64_t raw;
 238        uint32_t tenms;
 239
 240        raw = hp_sdc_rtc_read_i8042timer(HP_SDC_CMD_LOAD_DT, 3);
 241        if (raw < 0) return -1;
 242
 243        tenms = (uint32_t)raw & 0xffffff;
 244
 245        res->tv_nsec = (long)(tenms % 100) * 10000 * 1000;
 246        res->tv_sec  = (time64_t)(tenms / 100);
 247
 248        return 0;
 249}
 250
 251
 252/* Read the i8042 cycle timer (a.k.a. periodic) */
 253static inline int hp_sdc_rtc_read_ct(struct timespec64 *res) {
 254        int64_t raw;
 255        uint32_t tenms;
 256
 257        raw = hp_sdc_rtc_read_i8042timer(HP_SDC_CMD_LOAD_CT, 3);
 258        if (raw < 0) return -1;
 259
 260        tenms = (uint32_t)raw & 0xffffff;
 261
 262        res->tv_nsec = (long)(tenms % 100) * 10000 * 1000;
 263        res->tv_sec  = (time64_t)(tenms / 100);
 264
 265        return 0;
 266}
 267
 268static int hp_sdc_rtc_proc_show(struct seq_file *m, void *v)
 269{
 270#define YN(bit) ("no")
 271#define NY(bit) ("yes")
 272        struct rtc_time tm;
 273        struct timespec64 tv;
 274
 275        memset(&tm, 0, sizeof(struct rtc_time));
 276
 277        if (hp_sdc_rtc_read_bbrtc(&tm)) {
 278                seq_puts(m, "BBRTC\t\t: READ FAILED!\n");
 279        } else {
 280                seq_printf(m,
 281                             "rtc_time\t: %ptRt\n"
 282                             "rtc_date\t: %ptRd\n"
 283                             "rtc_epoch\t: %04lu\n",
 284                             &tm, &tm, epoch);
 285        }
 286
 287        if (hp_sdc_rtc_read_rt(&tv)) {
 288                seq_puts(m, "i8042 rtc\t: READ FAILED!\n");
 289        } else {
 290                seq_printf(m, "i8042 rtc\t: %lld.%02ld seconds\n",
 291                             (s64)tv.tv_sec, (long)tv.tv_nsec/1000000L);
 292        }
 293
 294        if (hp_sdc_rtc_read_fhs(&tv)) {
 295                seq_puts(m, "handshake\t: READ FAILED!\n");
 296        } else {
 297                seq_printf(m, "handshake\t: %lld.%02ld seconds\n",
 298                             (s64)tv.tv_sec, (long)tv.tv_nsec/1000000L);
 299        }
 300
 301        if (hp_sdc_rtc_read_mt(&tv)) {
 302                seq_puts(m, "alarm\t\t: READ FAILED!\n");
 303        } else {
 304                seq_printf(m, "alarm\t\t: %lld.%02ld seconds\n",
 305                             (s64)tv.tv_sec, (long)tv.tv_nsec/1000000L);
 306        }
 307
 308        if (hp_sdc_rtc_read_dt(&tv)) {
 309                seq_puts(m, "delay\t\t: READ FAILED!\n");
 310        } else {
 311                seq_printf(m, "delay\t\t: %lld.%02ld seconds\n",
 312                             (s64)tv.tv_sec, (long)tv.tv_nsec/1000000L);
 313        }
 314
 315        if (hp_sdc_rtc_read_ct(&tv)) {
 316                seq_puts(m, "periodic\t: READ FAILED!\n");
 317        } else {
 318                seq_printf(m, "periodic\t: %lld.%02ld seconds\n",
 319                             (s64)tv.tv_sec, (long)tv.tv_nsec/1000000L);
 320        }
 321
 322        seq_printf(m,
 323                     "DST_enable\t: %s\n"
 324                     "BCD\t\t: %s\n"
 325                     "24hr\t\t: %s\n"
 326                     "square_wave\t: %s\n"
 327                     "alarm_IRQ\t: %s\n"
 328                     "update_IRQ\t: %s\n"
 329                     "periodic_IRQ\t: %s\n"
 330                     "periodic_freq\t: %ld\n"
 331                     "batt_status\t: %s\n",
 332                     YN(RTC_DST_EN),
 333                     NY(RTC_DM_BINARY),
 334                     YN(RTC_24H),
 335                     YN(RTC_SQWE),
 336                     YN(RTC_AIE),
 337                     YN(RTC_UIE),
 338                     YN(RTC_PIE),
 339                     1UL,
 340                     1 ? "okay" : "dead");
 341
 342        return 0;
 343#undef YN
 344#undef NY
 345}
 346
 347static int __init hp_sdc_rtc_init(void)
 348{
 349        int ret;
 350
 351#ifdef __mc68000__
 352        if (!MACH_IS_HP300)
 353                return -ENODEV;
 354#endif
 355
 356        sema_init(&i8042tregs, 1);
 357
 358        if ((ret = hp_sdc_request_timer_irq(&hp_sdc_rtc_isr)))
 359                return ret;
 360
 361        proc_create_single("driver/rtc", 0, NULL, hp_sdc_rtc_proc_show);
 362
 363        printk(KERN_INFO "HP i8042 SDC + MSM-58321 RTC support loaded "
 364                         "(RTC v " RTC_VERSION ")\n");
 365
 366        return 0;
 367}
 368
 369static void __exit hp_sdc_rtc_exit(void)
 370{
 371        remove_proc_entry ("driver/rtc", NULL);
 372        hp_sdc_release_timer_irq(hp_sdc_rtc_isr);
 373        printk(KERN_INFO "HP i8042 SDC + MSM-58321 RTC support unloaded\n");
 374}
 375
 376module_init(hp_sdc_rtc_init);
 377module_exit(hp_sdc_rtc_exit);
 378