linux/drivers/input/serio/hp_sdc_mlc.c
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   1/*
   2 * Access to HP-HIL MLC through HP System Device Controller.
   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 * HP-HIL Technical Reference Manual.  Hewlett Packard Product No. 45918A
  31 * System Device Controller Microprocessor Firmware Theory of Operation
  32 *      for Part Number 1820-4784 Revision B.  Dwg No. A-1820-4784-2
  33 *
  34 */
  35
  36#include <linux/hil_mlc.h>
  37#include <linux/hp_sdc.h>
  38#include <linux/errno.h>
  39#include <linux/kernel.h>
  40#include <linux/module.h>
  41#include <linux/init.h>
  42#include <linux/string.h>
  43#include <linux/semaphore.h>
  44
  45#define PREFIX "HP SDC MLC: "
  46
  47static hil_mlc hp_sdc_mlc;
  48
  49MODULE_AUTHOR("Brian S. Julin <bri@calyx.com>");
  50MODULE_DESCRIPTION("Glue for onboard HIL MLC in HP-PARISC machines");
  51MODULE_LICENSE("Dual BSD/GPL");
  52
  53static struct hp_sdc_mlc_priv_s {
  54        int emtestmode;
  55        hp_sdc_transaction trans;
  56        u8 tseq[16];
  57        int got5x;
  58} hp_sdc_mlc_priv;
  59
  60/************************* Interrupt context ******************************/
  61static void hp_sdc_mlc_isr (int irq, void *dev_id,
  62                            uint8_t status, uint8_t data)
  63{
  64        int idx;
  65        hil_mlc *mlc = &hp_sdc_mlc;
  66
  67        write_lock(&mlc->lock);
  68        if (mlc->icount < 0) {
  69                printk(KERN_WARNING PREFIX "HIL Overflow!\n");
  70                up(&mlc->isem);
  71                goto out;
  72        }
  73        idx = 15 - mlc->icount;
  74        if ((status & HP_SDC_STATUS_IRQMASK) == HP_SDC_STATUS_HILDATA) {
  75                mlc->ipacket[idx] |= data | HIL_ERR_INT;
  76                mlc->icount--;
  77                if (hp_sdc_mlc_priv.got5x || !idx)
  78                        goto check;
  79                if ((mlc->ipacket[idx - 1] & HIL_PKT_ADDR_MASK) !=
  80                    (mlc->ipacket[idx] & HIL_PKT_ADDR_MASK)) {
  81                        mlc->ipacket[idx] &= ~HIL_PKT_ADDR_MASK;
  82                        mlc->ipacket[idx] |= (mlc->ipacket[idx - 1]
  83                                                & HIL_PKT_ADDR_MASK);
  84                }
  85                goto check;
  86        }
  87        /* We know status is 5X */
  88        if (data & HP_SDC_HIL_ISERR)
  89                goto err;
  90        mlc->ipacket[idx] =
  91                (data & HP_SDC_HIL_R1MASK) << HIL_PKT_ADDR_SHIFT;
  92        hp_sdc_mlc_priv.got5x = 1;
  93        goto out;
  94
  95 check:
  96        hp_sdc_mlc_priv.got5x = 0;
  97        if (mlc->imatch == 0)
  98                goto done;
  99        if ((mlc->imatch == (HIL_ERR_INT | HIL_PKT_CMD | HIL_CMD_POL))
 100            && (mlc->ipacket[idx] == (mlc->imatch | idx)))
 101                goto done;
 102        if (mlc->ipacket[idx] == mlc->imatch)
 103                goto done;
 104        goto out;
 105
 106 err:
 107        printk(KERN_DEBUG PREFIX "err code %x\n", data);
 108
 109        switch (data) {
 110        case HP_SDC_HIL_RC_DONE:
 111                printk(KERN_WARNING PREFIX "Bastard SDC reconfigured loop!\n");
 112                break;
 113
 114        case HP_SDC_HIL_ERR:
 115                mlc->ipacket[idx] |= HIL_ERR_INT | HIL_ERR_PERR |
 116                                        HIL_ERR_FERR | HIL_ERR_FOF;
 117                break;
 118
 119        case HP_SDC_HIL_TO:
 120                mlc->ipacket[idx] |= HIL_ERR_INT | HIL_ERR_LERR;
 121                break;
 122
 123        case HP_SDC_HIL_RC:
 124                printk(KERN_WARNING PREFIX "Bastard SDC decided to reconfigure loop!\n");
 125                break;
 126
 127        default:
 128                printk(KERN_WARNING PREFIX "Unknown HIL Error status (%x)!\n", data);
 129                break;
 130        }
 131
 132        /* No more data will be coming due to an error. */
 133 done:
 134        tasklet_schedule(mlc->tasklet);
 135        up(&mlc->isem);
 136 out:
 137        write_unlock(&mlc->lock);
 138}
 139
 140
 141/******************** Tasklet or userspace context functions ****************/
 142
 143static int hp_sdc_mlc_in(hil_mlc *mlc, suseconds_t timeout)
 144{
 145        struct hp_sdc_mlc_priv_s *priv;
 146        int rc = 2;
 147
 148        priv = mlc->priv;
 149
 150        /* Try to down the semaphore */
 151        if (down_trylock(&mlc->isem)) {
 152                struct timeval tv;
 153                if (priv->emtestmode) {
 154                        mlc->ipacket[0] =
 155                                HIL_ERR_INT | (mlc->opacket &
 156                                               (HIL_PKT_CMD |
 157                                                HIL_PKT_ADDR_MASK |
 158                                                HIL_PKT_DATA_MASK));
 159                        mlc->icount = 14;
 160                        /* printk(KERN_DEBUG PREFIX ">[%x]\n", mlc->ipacket[0]); */
 161                        goto wasup;
 162                }
 163                do_gettimeofday(&tv);
 164                tv.tv_usec += USEC_PER_SEC * (tv.tv_sec - mlc->instart.tv_sec);
 165                if (tv.tv_usec - mlc->instart.tv_usec > mlc->intimeout) {
 166                        /*      printk("!%i %i",
 167                                tv.tv_usec - mlc->instart.tv_usec,
 168                                mlc->intimeout);
 169                         */
 170                        rc = 1;
 171                        up(&mlc->isem);
 172                }
 173                goto done;
 174        }
 175 wasup:
 176        up(&mlc->isem);
 177        rc = 0;
 178 done:
 179        return rc;
 180}
 181
 182static int hp_sdc_mlc_cts(hil_mlc *mlc)
 183{
 184        struct hp_sdc_mlc_priv_s *priv;
 185
 186        priv = mlc->priv;
 187
 188        /* Try to down the semaphores -- they should be up. */
 189        BUG_ON(down_trylock(&mlc->isem));
 190        BUG_ON(down_trylock(&mlc->osem));
 191
 192        up(&mlc->isem);
 193        up(&mlc->osem);
 194
 195        if (down_trylock(&mlc->csem)) {
 196                if (priv->trans.act.semaphore != &mlc->csem)
 197                        goto poll;
 198                else
 199                        goto busy;
 200        }
 201
 202        if (!(priv->tseq[4] & HP_SDC_USE_LOOP))
 203                goto done;
 204
 205 poll:
 206        priv->trans.act.semaphore = &mlc->csem;
 207        priv->trans.actidx = 0;
 208        priv->trans.idx = 1;
 209        priv->trans.endidx = 5;
 210        priv->tseq[0] =
 211                HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN | HP_SDC_ACT_SEMAPHORE;
 212        priv->tseq[1] = HP_SDC_CMD_READ_USE;
 213        priv->tseq[2] = 1;
 214        priv->tseq[3] = 0;
 215        priv->tseq[4] = 0;
 216        __hp_sdc_enqueue_transaction(&priv->trans);
 217 busy:
 218        return 1;
 219 done:
 220        priv->trans.act.semaphore = &mlc->osem;
 221        up(&mlc->csem);
 222        return 0;
 223}
 224
 225static void hp_sdc_mlc_out(hil_mlc *mlc)
 226{
 227        struct hp_sdc_mlc_priv_s *priv;
 228
 229        priv = mlc->priv;
 230
 231        /* Try to down the semaphore -- it should be up. */
 232        BUG_ON(down_trylock(&mlc->osem));
 233
 234        if (mlc->opacket & HIL_DO_ALTER_CTRL)
 235                goto do_control;
 236
 237 do_data:
 238        if (priv->emtestmode) {
 239                up(&mlc->osem);
 240                return;
 241        }
 242        /* Shouldn't be sending commands when loop may be busy */
 243        BUG_ON(down_trylock(&mlc->csem));
 244        up(&mlc->csem);
 245
 246        priv->trans.actidx = 0;
 247        priv->trans.idx = 1;
 248        priv->trans.act.semaphore = &mlc->osem;
 249        priv->trans.endidx = 6;
 250        priv->tseq[0] =
 251                HP_SDC_ACT_DATAREG | HP_SDC_ACT_POSTCMD | HP_SDC_ACT_SEMAPHORE;
 252        priv->tseq[1] = 0x7;
 253        priv->tseq[2] =
 254                (mlc->opacket &
 255                 (HIL_PKT_ADDR_MASK | HIL_PKT_CMD))
 256                   >> HIL_PKT_ADDR_SHIFT;
 257        priv->tseq[3] =
 258                (mlc->opacket & HIL_PKT_DATA_MASK)
 259                  >> HIL_PKT_DATA_SHIFT;
 260        priv->tseq[4] = 0;  /* No timeout */
 261        if (priv->tseq[3] == HIL_CMD_DHR)
 262                priv->tseq[4] = 1;
 263        priv->tseq[5] = HP_SDC_CMD_DO_HIL;
 264        goto enqueue;
 265
 266 do_control:
 267        priv->emtestmode = mlc->opacket & HIL_CTRL_TEST;
 268
 269        /* we cannot emulate this, it should not be used. */
 270        BUG_ON((mlc->opacket & (HIL_CTRL_APE | HIL_CTRL_IPF)) == HIL_CTRL_APE);
 271
 272        if ((mlc->opacket & HIL_CTRL_ONLY) == HIL_CTRL_ONLY)
 273                goto control_only;
 274
 275        /* Should not send command/data after engaging APE */
 276        BUG_ON(mlc->opacket & HIL_CTRL_APE);
 277
 278        /* Disengaging APE this way would not be valid either since
 279         * the loop must be allowed to idle.
 280         *
 281         * So, it works out that we really never actually send control
 282         * and data when using SDC, we just send the data.
 283         */
 284        goto do_data;
 285
 286 control_only:
 287        priv->trans.actidx = 0;
 288        priv->trans.idx = 1;
 289        priv->trans.act.semaphore = &mlc->osem;
 290        priv->trans.endidx = 4;
 291        priv->tseq[0] =
 292          HP_SDC_ACT_PRECMD | HP_SDC_ACT_DATAOUT | HP_SDC_ACT_SEMAPHORE;
 293        priv->tseq[1] = HP_SDC_CMD_SET_LPC;
 294        priv->tseq[2] = 1;
 295        /* priv->tseq[3] = (mlc->ddc + 1) | HP_SDC_LPS_ACSUCC; */
 296        priv->tseq[3] = 0;
 297        if (mlc->opacket & HIL_CTRL_APE) {
 298                priv->tseq[3] |= HP_SDC_LPC_APE_IPF;
 299                BUG_ON(down_trylock(&mlc->csem));
 300        }
 301 enqueue:
 302        hp_sdc_enqueue_transaction(&priv->trans);
 303}
 304
 305static int __init hp_sdc_mlc_init(void)
 306{
 307        hil_mlc *mlc = &hp_sdc_mlc;
 308        int err;
 309
 310#ifdef __mc68000__
 311        if (!MACH_IS_HP300)
 312                return -ENODEV;
 313#endif
 314
 315        printk(KERN_INFO PREFIX "Registering the System Domain Controller's HIL MLC.\n");
 316
 317        hp_sdc_mlc_priv.emtestmode = 0;
 318        hp_sdc_mlc_priv.trans.seq = hp_sdc_mlc_priv.tseq;
 319        hp_sdc_mlc_priv.trans.act.semaphore = &mlc->osem;
 320        hp_sdc_mlc_priv.got5x = 0;
 321
 322        mlc->cts = &hp_sdc_mlc_cts;
 323        mlc->in = &hp_sdc_mlc_in;
 324        mlc->out = &hp_sdc_mlc_out;
 325        mlc->priv = &hp_sdc_mlc_priv;
 326
 327        err = hil_mlc_register(mlc);
 328        if (err) {
 329                printk(KERN_WARNING PREFIX "Failed to register MLC structure with hil_mlc\n");
 330                return err;
 331        }
 332
 333        if (hp_sdc_request_hil_irq(&hp_sdc_mlc_isr)) {
 334                printk(KERN_WARNING PREFIX "Request for raw HIL ISR hook denied\n");
 335                if (hil_mlc_unregister(mlc))
 336                        printk(KERN_ERR PREFIX "Failed to unregister MLC structure with hil_mlc.\n"
 337                                "This is bad.  Could cause an oops.\n");
 338                return -EBUSY;
 339        }
 340
 341        return 0;
 342}
 343
 344static void __exit hp_sdc_mlc_exit(void)
 345{
 346        hil_mlc *mlc = &hp_sdc_mlc;
 347
 348        if (hp_sdc_release_hil_irq(&hp_sdc_mlc_isr))
 349                printk(KERN_ERR PREFIX "Failed to release the raw HIL ISR hook.\n"
 350                        "This is bad.  Could cause an oops.\n");
 351
 352        if (hil_mlc_unregister(mlc))
 353                printk(KERN_ERR PREFIX "Failed to unregister MLC structure with hil_mlc.\n"
 354                        "This is bad.  Could cause an oops.\n");
 355}
 356
 357module_init(hp_sdc_mlc_init);
 358module_exit(hp_sdc_mlc_exit);
 359