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 <asm/dma.h>
  32 #include <linux/uaccess.h>
  33 #include <asm/superio.h>
  34
  35 #include <linux/parport.h>
  36 #include <asm/pdc.h>
  37 #include <asm/parisc-device.h>
  38 #include <asm/hardware.h>
  39 #include "parport_gsc.h"
  40
  41
  42 MODULE_AUTHOR("Helge Deller <deller@gmx.de>");
  43 MODULE_DESCRIPTION("HP-PARISC PC-style parallel port driver");
  44 MODULE_SUPPORTED_DEVICE("integrated PC-style parallel port");
  45 MODULE_LICENSE("GPL");
  46
  47
  48 /*
  49  * Clear TIMEOUT BIT in EPP MODE
  50  *
  51  * This is also used in SPP detection.
  52  */
  53 static int clear_epp_timeout(struct parport *pb)
  54 {
  55         unsigned char r;
  56
  57         if (!(parport_gsc_read_status(pb) & 0x01))
  58                 return 1;
  59
  60         /* To clear timeout some chips require double read */
  61         parport_gsc_read_status(pb);
  62         r = parport_gsc_read_status(pb);
  63         parport_writeb (r | 0x01, STATUS (pb)); /* Some reset by writing 1 */
  64         parport_writeb (r & 0xfe, STATUS (pb)); /* Others by writing 0 */
  65         r = parport_gsc_read_status(pb);
  66
  67         return !(r & 0x01);
  68 }
  69
  70 /*
  71  * Access functions.
  72  *
  73  * Most of these aren't static because they may be used by the
  74  * parport_xxx_yyy macros.  extern __inline__ versions of several
  75  * of these are in parport_gsc.h.
  76  */
  77
  78 void parport_gsc_init_state(struct pardevice *dev, struct parport_state *s)
  79 {
  80         s->u.pc.ctr = 0xc | (dev->irq_func ? 0x10 : 0x0);
  81 }
  82
  83 void parport_gsc_save_state(struct parport *p, struct parport_state *s)
  84 {
  85         s->u.pc.ctr = parport_readb (CONTROL (p));
  86 }
  87
  88 void parport_gsc_restore_state(struct parport *p, struct parport_state *s)
  89 {
  90         parport_writeb (s->u.pc.ctr, CONTROL (p));
  91 }
  92
  93 struct parport_operations parport_gsc_ops =
  94 {
  95         .write_data     = parport_gsc_write_data,
  96         .read_data      = parport_gsc_read_data,
  97
  98         .write_control  = parport_gsc_write_control,
  99         .read_control   = parport_gsc_read_control,
 100         .frob_control   = parport_gsc_frob_control,
 101
 102         .read_status    = parport_gsc_read_status,
 103
 104         .enable_irq     = parport_gsc_enable_irq,
 105         .disable_irq    = parport_gsc_disable_irq,
 106
 107         .data_forward   = parport_gsc_data_forward,
 108         .data_reverse   = parport_gsc_data_reverse,
 109
 110         .init_state     = parport_gsc_init_state,
 111         .save_state     = parport_gsc_save_state,
 112         .restore_state  = parport_gsc_restore_state,
 113
 114         .epp_write_data = parport_ieee1284_epp_write_data,
 115         .epp_read_data  = parport_ieee1284_epp_read_data,
 116         .epp_write_addr = parport_ieee1284_epp_write_addr,
 117         .epp_read_addr  = parport_ieee1284_epp_read_addr,
 118
 119         .ecp_write_data = parport_ieee1284_ecp_write_data,
 120         .ecp_read_data  = parport_ieee1284_ecp_read_data,
 121         .ecp_write_addr = parport_ieee1284_ecp_write_addr,
 122
 123         .compat_write_data      = parport_ieee1284_write_compat,
 124         .nibble_read_data       = parport_ieee1284_read_nibble,
 125         .byte_read_data         = parport_ieee1284_read_byte,
 126
 127         .owner          = THIS_MODULE,
 128 };
 129
 130 /* --- Mode detection ------------------------------------- */
 131
 132 /*
 133  * Checks for port existence, all ports support SPP MODE
 134  */
 135 static int parport_SPP_supported(struct parport *pb)
 136 {
 137         unsigned char r, w;
 138
 139         /*
 140          * first clear an eventually pending EPP timeout
 141          * I (sailer@ife.ee.ethz.ch) have an SMSC chipset
 142          * that does not even respond to SPP cycles if an EPP
 143          * timeout is pending
 144          */
 145         clear_epp_timeout(pb);
 146
 147         /* Do a simple read-write test to make sure the port exists. */
 148         w = 0xc;
 149         parport_writeb (w, CONTROL (pb));
 150
 151         /* Is there a control register that we can read from?  Some
 152          * ports don't allow reads, so read_control just returns a
 153          * software copy. Some ports _do_ allow reads, so bypass the
 154          * software copy here.  In addition, some bits aren't
 155          * writable. */
 156         r = parport_readb (CONTROL (pb));
 157         if ((r & 0xf) == w) {
 158                 w = 0xe;
 159                 parport_writeb (w, CONTROL (pb));
 160                 r = parport_readb (CONTROL (pb));
 161                 parport_writeb (0xc, CONTROL (pb));
 162                 if ((r & 0xf) == w)
 163                         return PARPORT_MODE_PCSPP;
 164         }
 165
 166         /* Try the data register.  The data lines aren't tri-stated at
 167          * this stage, so we expect back what we wrote. */
 168         w = 0xaa;
 169         parport_gsc_write_data (pb, w);
 170         r = parport_gsc_read_data (pb);
 171         if (r == w) {
 172                 w = 0x55;
 173                 parport_gsc_write_data (pb, w);
 174                 r = parport_gsc_read_data (pb);
 175                 if (r == w)
 176                         return PARPORT_MODE_PCSPP;
 177         }
 178
 179         return 0;
 180 }
 181
 182 /* Detect PS/2 support.
 183  *
 184  * Bit 5 (0x20) sets the PS/2 data direction; setting this high
 185  * allows us to read data from the data lines.  In theory we would get back
 186  * 0xff but any peripheral attached to the port may drag some or all of the
 187  * lines down to zero.  So if we get back anything that isn't the contents
 188  * of the data register we deem PS/2 support to be present.
 189  *
 190  * Some SPP ports have "half PS/2" ability - you can't turn off the line
 191  * drivers, but an external peripheral with sufficiently beefy drivers of
 192  * its own can overpower them and assert its own levels onto the bus, from
 193  * where they can then be read back as normal.  Ports with this property
 194  * and the right type of device attached are likely to fail the SPP test,
 195  * (as they will appear to have stuck bits) and so the fact that they might
 196  * be misdetected here is rather academic.
 197  */
 198
 199 static int parport_PS2_supported(struct parport *pb)
 200 {
 201         int ok = 0;
 202
 203         clear_epp_timeout(pb);
 204
 205         /* try to tri-state the buffer */
 206         parport_gsc_data_reverse (pb);
 207
 208         parport_gsc_write_data(pb, 0x55);
 209         if (parport_gsc_read_data(pb) != 0x55) ok++;
 210
 211         parport_gsc_write_data(pb, 0xaa);
 212         if (parport_gsc_read_data(pb) != 0xaa) ok++;
 213
 214         /* cancel input mode */
 215         parport_gsc_data_forward (pb);
 216
 217         if (ok) {
 218                 pb->modes |= PARPORT_MODE_TRISTATE;
 219         } else {
 220                 struct parport_gsc_private *priv = pb->private_data;
 221                 priv->ctr_writable &= ~0x20;
 222         }
 223
 224         return ok;
 225 }
 226
 227
 228 /* --- Initialisation code -------------------------------- */
 229
 230 struct parport *parport_gsc_probe_port(unsigned long base,
 231                                        unsigned long base_hi, int irq,
 232                                        int dma, struct parisc_device *padev)
 233 {
 234         struct parport_gsc_private *priv;
 235         struct parport_operations *ops;
 236         struct parport tmp;
 237         struct parport *p = &tmp;
 238
 239         priv = kzalloc (sizeof (struct parport_gsc_private), GFP_KERNEL);
 240         if (!priv) {
 241                 printk(KERN_DEBUG "parport (0x%lx): no memory!\n", base);
 242                 return NULL;
 243         }
 244         ops = kmemdup(&parport_gsc_ops, sizeof(struct parport_operations),
 245                       GFP_KERNEL);
 246         if (!ops) {
 247                 printk(KERN_DEBUG "parport (0x%lx): no memory for ops!\n",
 248                        base);
 249                 kfree (priv);
 250                 return NULL;
 251         }
 252         priv->ctr = 0xc;
 253         priv->ctr_writable = 0xff;
 254         priv->dma_buf = NULL;
 255         priv->dma_handle = 0;
 256         p->base = base;
 257         p->base_hi = base_hi;
 258         p->irq = irq;
 259         p->dma = dma;
 260         p->modes = PARPORT_MODE_PCSPP | PARPORT_MODE_SAFEININT;
 261         p->ops = ops;
 262         p->private_data = priv;
 263         p->physport = p;
 264         if (!parport_SPP_supported (p)) {
 265                 /* No port. */
 266                 kfree (priv);
 267                 kfree(ops);
 268                 return NULL;
 269         }
 270         parport_PS2_supported (p);
 271
 272         if (!(p = parport_register_port(base, PARPORT_IRQ_NONE,
 273                                         PARPORT_DMA_NONE, ops))) {
 274                 kfree (priv);
 275                 kfree (ops);
 276                 return NULL;
 277         }
 278
 279         p->dev = &padev->dev;
 280         p->base_hi = base_hi;
 281         p->modes = tmp.modes;
 282         p->size = (p->modes & PARPORT_MODE_EPP)?8:3;
 283         p->private_data = priv;
 284
 285         pr_info("%s: PC-style at 0x%lx", p->name, p->base);
 286         p->irq = irq;
 287         if (p->irq == PARPORT_IRQ_AUTO) {
 288                 p->irq = PARPORT_IRQ_NONE;
 289         }
 290         if (p->irq != PARPORT_IRQ_NONE) {
 291                 pr_cont(", irq %d", p->irq);
 292
 293                 if (p->dma == PARPORT_DMA_AUTO) {
 294                         p->dma = PARPORT_DMA_NONE;
 295                 }
 296         }
 297         if (p->dma == PARPORT_DMA_AUTO) /* To use DMA, giving the irq
 298                                            is mandatory (see above) */
 299                 p->dma = PARPORT_DMA_NONE;
 300
 301         pr_cont(" [");
 302 #define printmode(x)                                                    \
 303 do {                                                                    \
 304         if (p->modes & PARPORT_MODE_##x)                                \
 305                 pr_cont("%s%s", f++ ? "," : "", #x);                    \
 306 } while (0)
 307         {
 308                 int f = 0;
 309                 printmode(PCSPP);
 310                 printmode(TRISTATE);
 311                 printmode(COMPAT);
 312                 printmode(EPP);
 313 //              printmode(ECP);
 314 //              printmode(DMA);
 315         }
 316 #undef printmode
 317         pr_cont("]\n");
 318
 319         if (p->irq != PARPORT_IRQ_NONE) {
 320                 if (request_irq (p->irq, parport_irq_handler,
 321                                  0, p->name, p)) {
 322                         pr_warn("%s: irq %d in use, resorting to polled operation\n",
 323                                 p->name, p->irq);
 324                         p->irq = PARPORT_IRQ_NONE;
 325                         p->dma = PARPORT_DMA_NONE;
 326                 }
 327         }
 328
 329         /* Done probing.  Now put the port into a sensible start-up state. */
 330
 331         parport_gsc_write_data(p, 0);
 332         parport_gsc_data_forward (p);
 333
 334         /* Now that we've told the sharing engine about the port, and
 335            found out its characteristics, let the high-level drivers
 336            know about it. */
 337         parport_announce_port (p);
 338
 339         return p;
 340 }
 341
 342
 343 #define PARPORT_GSC_OFFSET 0x800
 344
 345 static int parport_count;
 346
 347 static int __init parport_init_chip(struct parisc_device *dev)
 348 {
 349         struct parport *p;
 350         unsigned long port;
 351
 352         if (!dev->irq) {
 353                 pr_warn("IRQ not found for parallel device at 0x%llx\n",
 354                         (unsigned long long)dev->hpa.start);
 355                 return -ENODEV;
 356         }
 357
 358         port = dev->hpa.start + PARPORT_GSC_OFFSET;
 359
 360         /* some older machines with ASP-chip don't support
 361          * the enhanced parport modes.
 362          */
 363         if (boot_cpu_data.cpu_type > pcxt && !pdc_add_valid(port+4)) {
 364
 365                 /* Initialize bidirectional-mode (0x10) & data-tranfer-mode #1 (0x20) */
 366                 pr_info("%s: initialize bidirectional-mode\n", __func__);
 367                 parport_writeb ( (0x10 + 0x20), port + 4);
 368
 369         } else {
 370                 pr_info("%s: enhanced parport-modes not supported\n", __func__);
 371         }
 372
 373         p = parport_gsc_probe_port(port, 0, dev->irq,
 374                         /* PARPORT_IRQ_NONE */ PARPORT_DMA_NONE, dev);
 375         if (p)
 376                 parport_count++;
 377         dev_set_drvdata(&dev->dev, p);
 378
 379         return 0;
 380 }
 381
 382 static int __exit parport_remove_chip(struct parisc_device *dev)
 383 {
 384         struct parport *p = dev_get_drvdata(&dev->dev);
 385         if (p) {
 386                 struct parport_gsc_private *priv = p->private_data;
 387                 struct parport_operations *ops = p->ops;
 388                 parport_remove_port(p);
 389                 if (p->dma != PARPORT_DMA_NONE)
 390                         free_dma(p->dma);
 391                 if (p->irq != PARPORT_IRQ_NONE)
 392                         free_irq(p->irq, p);
 393                 if (priv->dma_buf)
 394                         pci_free_consistent(priv->dev, PAGE_SIZE,
 395                                             priv->dma_buf,
 396                                             priv->dma_handle);
 397                 kfree (p->private_data);
 398                 parport_put_port(p);
 399                 kfree (ops); /* hope no-one cached it */
 400         }
 401         return 0;
 402 }
 403
 404 static const struct parisc_device_id parport_tbl[] __initconst = {
 405         { HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x74 },
 406         { 0, }
 407 };
 408
 409 MODULE_DEVICE_TABLE(parisc, parport_tbl);
 410
 411 static struct parisc_driver parport_driver __refdata = {
 412         .name           = "Parallel",
 413         .id_table       = parport_tbl,
 414         .probe          = parport_init_chip,
 415         .remove         = __exit_p(parport_remove_chip),
 416 };
 417
 418 int parport_gsc_init(void)
 419 {
 420         return register_parisc_driver(&parport_driver);
 421 }
 422
 423 static void parport_gsc_exit(void)
 424 {
 425         unregister_parisc_driver(&parport_driver);
 426 }
 427
 428 module_init(parport_gsc_init);
 429 module_exit(parport_gsc_exit);