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