drivers/parport/parport_gsc.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      Low-level parallel-support for PC-style hardware integrated in the
   4  *      LASI-Controller (on GSC-Bus) for HP-PARISC Workstations
   5  *
   6  *      (C) 1999-2001 by Helge Deller <deller@gmx.de>
   7  *
   8  * based on parport_pc.c by
   9  *          Grant Guenther <grant@torque.net>
  10  *          Phil Blundell <philb@gnu.org>
  11  *          Tim Waugh <tim@cyberelk.demon.co.uk>
  12  *          Jose Renau <renau@acm.org>
  13  *          David Campbell
  14  *          Andrea Arcangeli
  15  */
  16
  17 #undef DEBUG    /* undef for production */
  18
  19 #include <linux/module.h>
  20 #include <linux/init.h>
  21 #include <linux/delay.h>
  22 #include <linux/errno.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/ioport.h>
  25 #include <linux/kernel.h>
  26 #include <linux/slab.h>
  27 #include <linux/pci.h>
  28 #include <linux/sysctl.h>
  29
  30 #include <asm/io.h>
  31 #include <linux/uaccess.h>
  32 #include <asm/superio.h>
  33
  34 #include <linux/parport.h>
  35 #include <asm/pdc.h>
  36 #include <asm/parisc-device.h>
  37 #include <asm/hardware.h>
  38 #include "parport_gsc.h"
  39
  40
  41 MODULE_AUTHOR("Helge Deller <deller@gmx.de>");
  42 MODULE_DESCRIPTION("HP-PARISC PC-style parallel port driver");
  43 MODULE_LICENSE("GPL");
  44
  45
  46 /*
  47  * Clear TIMEOUT BIT in EPP MODE
  48  *
  49  * This is also used in SPP detection.
  50  */
  51 static int clear_epp_timeout(struct parport *pb)
  52 {
  53         unsigned char r;
  54
  55         if (!(parport_gsc_read_status(pb) & 0x01))
  56                 return 1;
  57
  58         /* To clear timeout some chips require double read */
  59         parport_gsc_read_status(pb);
  60         r = parport_gsc_read_status(pb);
  61         parport_writeb (r | 0x01, STATUS (pb)); /* Some reset by writing 1 */
  62         parport_writeb (r & 0xfe, STATUS (pb)); /* Others by writing 0 */
  63         r = parport_gsc_read_status(pb);
  64
  65         return !(r & 0x01);
  66 }
  67
  68 /*
  69  * Access functions.
  70  *
  71  * Most of these aren't static because they may be used by the
  72  * parport_xxx_yyy macros.  extern __inline__ versions of several
  73  * of these are in parport_gsc.h.
  74  */
  75
  76 void parport_gsc_init_state(struct pardevice *dev, struct parport_state *s)
  77 {
  78         s->u.pc.ctr = 0xc | (dev->irq_func ? 0x10 : 0x0);
  79 }
  80
  81 void parport_gsc_save_state(struct parport *p, struct parport_state *s)
  82 {
  83         s->u.pc.ctr = parport_readb (CONTROL (p));
  84 }
  85
  86 void parport_gsc_restore_state(struct parport *p, struct parport_state *s)
  87 {
  88         parport_writeb (s->u.pc.ctr, CONTROL (p));
  89 }
  90
  91 struct parport_operations parport_gsc_ops =
  92 {
  93         .write_data     = parport_gsc_write_data,
  94         .read_data      = parport_gsc_read_data,
  95
  96         .write_control  = parport_gsc_write_control,
  97         .read_control   = parport_gsc_read_control,
  98         .frob_control   = parport_gsc_frob_control,
  99
 100         .read_status    = parport_gsc_read_status,
 101
 102         .enable_irq     = parport_gsc_enable_irq,
 103         .disable_irq    = parport_gsc_disable_irq,
 104
 105         .data_forward   = parport_gsc_data_forward,
 106         .data_reverse   = parport_gsc_data_reverse,
 107
 108         .init_state     = parport_gsc_init_state,
 109         .save_state     = parport_gsc_save_state,
 110         .restore_state  = parport_gsc_restore_state,
 111
 112         .epp_write_data = parport_ieee1284_epp_write_data,
 113         .epp_read_data  = parport_ieee1284_epp_read_data,
 114         .epp_write_addr = parport_ieee1284_epp_write_addr,
 115         .epp_read_addr  = parport_ieee1284_epp_read_addr,
 116
 117         .ecp_write_data = parport_ieee1284_ecp_write_data,
 118         .ecp_read_data  = parport_ieee1284_ecp_read_data,
 119         .ecp_write_addr = parport_ieee1284_ecp_write_addr,
 120
 121         .compat_write_data      = parport_ieee1284_write_compat,
 122         .nibble_read_data       = parport_ieee1284_read_nibble,
 123         .byte_read_data         = parport_ieee1284_read_byte,
 124
 125         .owner          = THIS_MODULE,
 126 };
 127
 128 /* --- Mode detection ------------------------------------- */
 129
 130 /*
 131  * Checks for port existence, all ports support SPP MODE
 132  */
 133 static int parport_SPP_supported(struct parport *pb)
 134 {
 135         unsigned char r, w;
 136
 137         /*
 138          * first clear an eventually pending EPP timeout
 139          * I (sailer@ife.ee.ethz.ch) have an SMSC chipset
 140          * that does not even respond to SPP cycles if an EPP
 141          * timeout is pending
 142          */
 143         clear_epp_timeout(pb);
 144
 145         /* Do a simple read-write test to make sure the port exists. */
 146         w = 0xc;
 147         parport_writeb (w, CONTROL (pb));
 148
 149         /* Is there a control register that we can read from?  Some
 150          * ports don't allow reads, so read_control just returns a
 151          * software copy. Some ports _do_ allow reads, so bypass the
 152          * software copy here.  In addition, some bits aren't
 153          * writable. */
 154         r = parport_readb (CONTROL (pb));
 155         if ((r & 0xf) == w) {
 156                 w = 0xe;
 157                 parport_writeb (w, CONTROL (pb));
 158                 r = parport_readb (CONTROL (pb));
 159                 parport_writeb (0xc, CONTROL (pb));
 160                 if ((r & 0xf) == w)
 161                         return PARPORT_MODE_PCSPP;
 162         }
 163
 164         /* Try the data register.  The data lines aren't tri-stated at
 165          * this stage, so we expect back what we wrote. */
 166         w = 0xaa;
 167         parport_gsc_write_data (pb, w);
 168         r = parport_gsc_read_data (pb);
 169         if (r == w) {
 170                 w = 0x55;
 171                 parport_gsc_write_data (pb, w);
 172                 r = parport_gsc_read_data (pb);
 173                 if (r == w)
 174                         return PARPORT_MODE_PCSPP;
 175         }
 176
 177         return 0;
 178 }
 179
 180 /* Detect PS/2 support.
 181  *
 182  * Bit 5 (0x20) sets the PS/2 data direction; setting this high
 183  * allows us to read data from the data lines.  In theory we would get back
 184  * 0xff but any peripheral attached to the port may drag some or all of the
 185  * lines down to zero.  So if we get back anything that isn't the contents
 186  * of the data register we deem PS/2 support to be present.
 187  *
 188  * Some SPP ports have "half PS/2" ability - you can't turn off the line
 189  * drivers, but an external peripheral with sufficiently beefy drivers of
 190  * its own can overpower them and assert its own levels onto the bus, from
 191  * where they can then be read back as normal.  Ports with this property
 192  * and the right type of device attached are likely to fail the SPP test,
 193  * (as they will appear to have stuck bits) and so the fact that they might
 194  * be misdetected here is rather academic.
 195  */
 196
 197 static int parport_PS2_supported(struct parport *pb)
 198 {
 199         int ok = 0;
 200
 201         clear_epp_timeout(pb);
 202
 203         /* try to tri-state the buffer */
 204         parport_gsc_data_reverse (pb);
 205
 206         parport_gsc_write_data(pb, 0x55);
 207         if (parport_gsc_read_data(pb) != 0x55) ok++;
 208
 209         parport_gsc_write_data(pb, 0xaa);
 210         if (parport_gsc_read_data(pb) != 0xaa) ok++;
 211
 212         /* cancel input mode */
 213         parport_gsc_data_forward (pb);
 214
 215         if (ok) {
 216                 pb->modes |= PARPORT_MODE_TRISTATE;
 217         } else {
 218                 struct parport_gsc_private *priv = pb->private_data;
 219                 priv->ctr_writable &= ~0x20;
 220         }
 221
 222         return ok;
 223 }
 224
 225
 226 /* --- Initialisation code -------------------------------- */
 227
 228 static struct parport *parport_gsc_probe_port(unsigned long base,
 229                                        unsigned long base_hi, int irq,
 230                                        struct parisc_device *padev)
 231 {
 232         struct parport_gsc_private *priv;
 233         struct parport_operations *ops;
 234         struct parport tmp;
 235         struct parport *p = &tmp;
 236
 237         priv = kzalloc (sizeof (struct parport_gsc_private), GFP_KERNEL);
 238         if (!priv) {
 239                 printk(KERN_DEBUG "parport (0x%lx): no memory!\n", base);
 240                 return NULL;
 241         }
 242         ops = kmemdup(&parport_gsc_ops, sizeof(struct parport_operations),
 243                       GFP_KERNEL);
 244         if (!ops) {
 245                 printk(KERN_DEBUG "parport (0x%lx): no memory for ops!\n",
 246                        base);
 247                 kfree (priv);
 248                 return NULL;
 249         }
 250         priv->ctr = 0xc;
 251         priv->ctr_writable = 0xff;
 252         p->base = base;
 253         p->base_hi = base_hi;
 254         p->irq = irq;
 255         p->modes = PARPORT_MODE_PCSPP | PARPORT_MODE_SAFEININT;
 256         p->ops = ops;
 257         p->private_data = priv;
 258         p->physport = p;
 259         if (!parport_SPP_supported (p)) {
 260                 /* No port. */
 261                 kfree (priv);
 262                 kfree(ops);
 263                 return NULL;
 264         }
 265         parport_PS2_supported (p);
 266
 267         if (!(p = parport_register_port(base, PARPORT_IRQ_NONE,
 268                                         PARPORT_DMA_NONE, ops))) {
 269                 kfree (priv);
 270                 kfree (ops);
 271                 return NULL;
 272         }
 273
 274         p->dev = &padev->dev;
 275         p->base_hi = base_hi;
 276         p->modes = tmp.modes;
 277         p->size = (p->modes & PARPORT_MODE_EPP)?8:3;
 278         p->private_data = priv;
 279
 280         pr_info("%s: PC-style at 0x%lx", p->name, p->base);
 281         p->irq = irq;
 282         if (p->irq == PARPORT_IRQ_AUTO) {
 283                 p->irq = PARPORT_IRQ_NONE;
 284         }
 285         if (p->irq != PARPORT_IRQ_NONE)
 286                 pr_cont(", irq %d", p->irq);
 287
 288         pr_cont(" [");
 289 #define printmode(x)                                                    \
 290 do {                                                                    \
 291         if (p->modes & PARPORT_MODE_##x)                                \
 292                 pr_cont("%s%s", f++ ? "," : "", #x);                    \
 293 } while (0)
 294         {
 295                 int f = 0;
 296                 printmode(PCSPP);
 297                 printmode(TRISTATE);
 298                 printmode(COMPAT);
 299                 printmode(EPP);
 300 //              printmode(ECP);
 301 //              printmode(DMA);
 302         }
 303 #undef printmode
 304         pr_cont("]\n");
 305
 306         if (p->irq != PARPORT_IRQ_NONE) {
 307                 if (request_irq (p->irq, parport_irq_handler,
 308                                  0, p->name, p)) {
 309                         pr_warn("%s: irq %d in use, resorting to polled operation\n",
 310                                 p->name, p->irq);
 311                         p->irq = PARPORT_IRQ_NONE;
 312                 }
 313         }
 314
 315         /* Done probing.  Now put the port into a sensible start-up state. */
 316
 317         parport_gsc_write_data(p, 0);
 318         parport_gsc_data_forward (p);
 319
 320         /* Now that we've told the sharing engine about the port, and
 321            found out its characteristics, let the high-level drivers
 322            know about it. */
 323         parport_announce_port (p);
 324
 325         return p;
 326 }
 327
 328
 329 #define PARPORT_GSC_OFFSET 0x800
 330
 331 static int parport_count;
 332
 333 static int __init parport_init_chip(struct parisc_device *dev)
 334 {
 335         struct parport *p;
 336         unsigned long port;
 337
 338         if (!dev->irq) {
 339                 pr_warn("IRQ not found for parallel device at 0x%llx\n",
 340                         (unsigned long long)dev->hpa.start);
 341                 return -ENODEV;
 342         }
 343
 344         port = dev->hpa.start + PARPORT_GSC_OFFSET;
 345
 346         /* some older machines with ASP-chip don't support
 347          * the enhanced parport modes.
 348          */
 349         if (boot_cpu_data.cpu_type > pcxt && !pdc_add_valid(port+4)) {
 350
 351                 /* Initialize bidirectional-mode (0x10) & data-tranfer-mode #1 (0x20) */
 352                 pr_info("%s: initialize bidirectional-mode\n", __func__);
 353                 parport_writeb ( (0x10 + 0x20), port + 4);
 354
 355         } else {
 356                 pr_info("%s: enhanced parport-modes not supported\n", __func__);
 357         }
 358
 359         p = parport_gsc_probe_port(port, 0, dev->irq, dev);
 360         if (p)
 361                 parport_count++;
 362         dev_set_drvdata(&dev->dev, p);
 363
 364         return 0;
 365 }
 366
 367 static void __exit parport_remove_chip(struct parisc_device *dev)
 368 {
 369         struct parport *p = dev_get_drvdata(&dev->dev);
 370         if (p) {
 371                 struct parport_operations *ops = p->ops;
 372                 parport_remove_port(p);
 373                 if (p->irq != PARPORT_IRQ_NONE)
 374                         free_irq(p->irq, p);
 375                 kfree (p->private_data);
 376                 parport_put_port(p);
 377                 kfree (ops); /* hope no-one cached it */
 378         }
 379 }
 380
 381 static const struct parisc_device_id parport_tbl[] __initconst = {
 382         { HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x74 },
 383         { 0, }
 384 };
 385
 386 MODULE_DEVICE_TABLE(parisc, parport_tbl);
 387
 388 static struct parisc_driver parport_driver __refdata = {
 389         .name           = "Parallel",
 390         .id_table       = parport_tbl,
 391         .probe          = parport_init_chip,
 392         .remove         = __exit_p(parport_remove_chip),
 393 };
 394
 395 static int parport_gsc_init(void)
 396 {
 397         return register_parisc_driver(&parport_driver);
 398 }
 399
 400 static void parport_gsc_exit(void)
 401 {
 402         unregister_parisc_driver(&parport_driver);
 403 }
 404
 405 module_init(parport_gsc_init);
 406 module_exit(parport_gsc_exit);