drivers/input/serio/gscps2.c

   1 /*
   2  * drivers/input/serio/gscps2.c
   3  *
   4  * Copyright (c) 2004-2006 Helge Deller <deller@gmx.de>
   5  * Copyright (c) 2002 Laurent Canet <canetl@esiee.fr>
   6  * Copyright (c) 2002 Thibaut Varene <varenet@parisc-linux.org>
   7  *
   8  * Pieces of code based on linux-2.4's hp_mouse.c & hp_keyb.c
   9  *      Copyright (c) 1999 Alex deVries <alex@onefishtwo.ca>
  10  *      Copyright (c) 1999-2000 Philipp Rumpf <prumpf@tux.org>
  11  *      Copyright (c) 2000 Xavier Debacker <debackex@esiee.fr>
  12  *      Copyright (c) 2000-2001 Thomas Marteau <marteaut@esiee.fr>
  13  *
  14  * HP GSC PS/2 port driver, found in PA/RISC Workstations
  15  *
  16  * This file is subject to the terms and conditions of the GNU General Public
  17  * License.  See the file "COPYING" in the main directory of this archive
  18  * for more details.
  19  *
  20  * TODO:
  21  * - Dino testing (did HP ever shipped a machine on which this port
  22  *                 was usable/enabled ?)
  23  */
  24
  25 #include <linux/init.h>
  26 #include <linux/module.h>
  27 #include <linux/slab.h>
  28 #include <linux/serio.h>
  29 #include <linux/input.h>
  30 #include <linux/interrupt.h>
  31 #include <linux/spinlock.h>
  32 #include <linux/delay.h>
  33 #include <linux/ioport.h>
  34
  35 #include <asm/irq.h>
  36 #include <asm/io.h>
  37 #include <asm/parisc-device.h>
  38
  39 MODULE_AUTHOR("Laurent Canet <canetl@esiee.fr>, Thibaut Varene <varenet@parisc-linux.org>, Helge Deller <deller@gmx.de>");
  40 MODULE_DESCRIPTION("HP GSC PS2 port driver");
  41 MODULE_LICENSE("GPL");
  42
  43 #define PFX "gscps2.c: "
  44
  45 /*
  46  * Driver constants
  47  */
  48
  49 /* various constants */
  50 #define ENABLE                  1
  51 #define DISABLE                 0
  52
  53 #define GSC_DINO_OFFSET         0x0800  /* offset for DINO controller versus LASI one */
  54
  55 /* PS/2 IO port offsets */
  56 #define GSC_ID                  0x00    /* device ID offset (see: GSC_ID_XXX) */
  57 #define GSC_RESET               0x00    /* reset port offset */
  58 #define GSC_RCVDATA             0x04    /* receive port offset */
  59 #define GSC_XMTDATA             0x04    /* transmit port offset */
  60 #define GSC_CONTROL             0x08    /* see: Control register bits */
  61 #define GSC_STATUS              0x0C    /* see: Status register bits */
  62
  63 /* Control register bits */
  64 #define GSC_CTRL_ENBL           0x01    /* enable interface */
  65 #define GSC_CTRL_LPBXR          0x02    /* loopback operation */
  66 #define GSC_CTRL_DIAG           0x20    /* directly control clock/data line */
  67 #define GSC_CTRL_DATDIR         0x40    /* data line direct control */
  68 #define GSC_CTRL_CLKDIR         0x80    /* clock line direct control */
  69
  70 /* Status register bits */
  71 #define GSC_STAT_RBNE           0x01    /* Receive Buffer Not Empty */
  72 #define GSC_STAT_TBNE           0x02    /* Transmit Buffer Not Empty */
  73 #define GSC_STAT_TERR           0x04    /* Timeout Error */
  74 #define GSC_STAT_PERR           0x08    /* Parity Error */
  75 #define GSC_STAT_CMPINTR        0x10    /* Composite Interrupt = irq on any port */
  76 #define GSC_STAT_DATSHD         0x40    /* Data Line Shadow */
  77 #define GSC_STAT_CLKSHD         0x80    /* Clock Line Shadow */
  78
  79 /* IDs returned by GSC_ID port register */
  80 #define GSC_ID_KEYBOARD         0       /* device ID values */
  81 #define GSC_ID_MOUSE            1
  82
  83
  84 static irqreturn_t gscps2_interrupt(int irq, void *dev);
  85
  86 #define BUFFER_SIZE 0x0f
  87
  88 /* GSC PS/2 port device struct */
  89 struct gscps2port {
  90         struct list_head node;
  91         struct parisc_device *padev;
  92         struct serio *port;
  93         spinlock_t lock;
  94         char *addr;
  95         u8 act, append; /* position in buffer[] */
  96         struct {
  97                 u8 data;
  98                 u8 str;
  99         } buffer[BUFFER_SIZE+1];
 100         int id;
 101 };
 102
 103 /*
 104  * Various HW level routines
 105  */
 106
 107 #define gscps2_readb_input(x)           readb((x)+GSC_RCVDATA)
 108 #define gscps2_readb_control(x)         readb((x)+GSC_CONTROL)
 109 #define gscps2_readb_status(x)          readb((x)+GSC_STATUS)
 110 #define gscps2_writeb_control(x, y)     writeb((x), (y)+GSC_CONTROL)
 111
 112
 113 /*
 114  * wait_TBE() - wait for Transmit Buffer Empty
 115  */
 116
 117 static int wait_TBE(char *addr)
 118 {
 119         int timeout = 25000; /* device is expected to react within 250 msec */
 120         while (gscps2_readb_status(addr) & GSC_STAT_TBNE) {
 121                 if (!--timeout)
 122                         return 0;       /* This should not happen */
 123                 udelay(10);
 124         }
 125         return 1;
 126 }
 127
 128
 129 /*
 130  * gscps2_flush() - flush the receive buffer
 131  */
 132
 133 static void gscps2_flush(struct gscps2port *ps2port)
 134 {
 135         while (gscps2_readb_status(ps2port->addr) & GSC_STAT_RBNE)
 136                 gscps2_readb_input(ps2port->addr);
 137         ps2port->act = ps2port->append = 0;
 138 }
 139
 140 /*
 141  * gscps2_writeb_output() - write a byte to the port
 142  *
 143  * returns 1 on success, 0 on error
 144  */
 145
 146 static inline int gscps2_writeb_output(struct gscps2port *ps2port, u8 data)
 147 {
 148         unsigned long flags;
 149         char *addr = ps2port->addr;
 150
 151         if (!wait_TBE(addr)) {
 152                 printk(KERN_DEBUG PFX "timeout - could not write byte %#x\n", data);
 153                 return 0;
 154         }
 155
 156         while (gscps2_readb_status(ps2port->addr) & GSC_STAT_RBNE)
 157                 /* wait */;
 158
 159         spin_lock_irqsave(&ps2port->lock, flags);
 160         writeb(data, addr+GSC_XMTDATA);
 161         spin_unlock_irqrestore(&ps2port->lock, flags);
 162
 163         /* this is ugly, but due to timing of the port it seems to be necessary. */
 164         mdelay(6);
 165
 166         /* make sure any received data is returned as fast as possible */
 167         /* this is important e.g. when we set the LEDs on the keyboard */
 168         gscps2_interrupt(0, NULL);
 169
 170         return 1;
 171 }
 172
 173
 174 /*
 175  * gscps2_enable() - enables or disables the port
 176  */
 177
 178 static void gscps2_enable(struct gscps2port *ps2port, int enable)
 179 {
 180         unsigned long flags;
 181         u8 data;
 182
 183         /* now enable/disable the port */
 184         spin_lock_irqsave(&ps2port->lock, flags);
 185         gscps2_flush(ps2port);
 186         data = gscps2_readb_control(ps2port->addr);
 187         if (enable)
 188                 data |= GSC_CTRL_ENBL;
 189         else
 190                 data &= ~GSC_CTRL_ENBL;
 191         gscps2_writeb_control(data, ps2port->addr);
 192         spin_unlock_irqrestore(&ps2port->lock, flags);
 193         wait_TBE(ps2port->addr);
 194         gscps2_flush(ps2port);
 195 }
 196
 197 /*
 198  * gscps2_reset() - resets the PS/2 port
 199  */
 200
 201 static void gscps2_reset(struct gscps2port *ps2port)
 202 {
 203         char *addr = ps2port->addr;
 204         unsigned long flags;
 205
 206         /* reset the interface */
 207         spin_lock_irqsave(&ps2port->lock, flags);
 208         gscps2_flush(ps2port);
 209         writeb(0xff, addr+GSC_RESET);
 210         gscps2_flush(ps2port);
 211         spin_unlock_irqrestore(&ps2port->lock, flags);
 212 }
 213
 214 static LIST_HEAD(ps2port_list);
 215
 216 /**
 217  * gscps2_interrupt() - Interruption service routine
 218  *
 219  * This function reads received PS/2 bytes and processes them on
 220  * all interfaces.
 221  * The problematic part here is, that the keyboard and mouse PS/2 port
 222  * share the same interrupt and it's not possible to send data if any
 223  * one of them holds input data. To solve this problem we try to receive
 224  * the data as fast as possible and handle the reporting to the upper layer
 225  * later.
 226  */
 227
 228 static irqreturn_t gscps2_interrupt(int irq, void *dev)
 229 {
 230         struct gscps2port *ps2port;
 231
 232         list_for_each_entry(ps2port, &ps2port_list, node) {
 233
 234           unsigned long flags;
 235           spin_lock_irqsave(&ps2port->lock, flags);
 236
 237           while ( (ps2port->buffer[ps2port->append].str =
 238                    gscps2_readb_status(ps2port->addr)) & GSC_STAT_RBNE ) {
 239                 ps2port->buffer[ps2port->append].data =
 240                                 gscps2_readb_input(ps2port->addr);
 241                 ps2port->append = ((ps2port->append+1) & BUFFER_SIZE);
 242           }
 243
 244           spin_unlock_irqrestore(&ps2port->lock, flags);
 245
 246         } /* list_for_each_entry */
 247
 248         /* all data was read from the ports - now report the data to upper layer */
 249
 250         list_for_each_entry(ps2port, &ps2port_list, node) {
 251
 252           while (ps2port->act != ps2port->append) {
 253
 254             unsigned int rxflags;
 255             u8 data, status;
 256
 257             /* Did new data arrived while we read existing data ?
 258                If yes, exit now and let the new irq handler start over again */
 259             if (gscps2_readb_status(ps2port->addr) & GSC_STAT_CMPINTR)
 260                 return IRQ_HANDLED;
 261
 262             status = ps2port->buffer[ps2port->act].str;
 263             data   = ps2port->buffer[ps2port->act].data;
 264
 265             ps2port->act = ((ps2port->act+1) & BUFFER_SIZE);
 266             rxflags =   ((status & GSC_STAT_TERR) ? SERIO_TIMEOUT : 0 ) |
 267                         ((status & GSC_STAT_PERR) ? SERIO_PARITY  : 0 );
 268
 269             serio_interrupt(ps2port->port, data, rxflags);
 270
 271           } /* while() */
 272
 273         } /* list_for_each_entry */
 274
 275         return IRQ_HANDLED;
 276 }
 277
 278
 279 /*
 280  * gscps2_write() - send a byte out through the aux interface.
 281  */
 282
 283 static int gscps2_write(struct serio *port, unsigned char data)
 284 {
 285         struct gscps2port *ps2port = port->port_data;
 286
 287         if (!gscps2_writeb_output(ps2port, data)) {
 288                 printk(KERN_DEBUG PFX "sending byte %#x failed.\n", data);
 289                 return -1;
 290         }
 291         return 0;
 292 }
 293
 294 /*
 295  * gscps2_open() is called when a port is opened by the higher layer.
 296  * It resets and enables the port.
 297  */
 298
 299 static int gscps2_open(struct serio *port)
 300 {
 301         struct gscps2port *ps2port = port->port_data;
 302
 303         gscps2_reset(ps2port);
 304
 305         /* enable it */
 306         gscps2_enable(ps2port, ENABLE);
 307
 308         gscps2_interrupt(0, NULL);
 309
 310         return 0;
 311 }
 312
 313 /*
 314  * gscps2_close() disables the port
 315  */
 316
 317 static void gscps2_close(struct serio *port)
 318 {
 319         struct gscps2port *ps2port = port->port_data;
 320         gscps2_enable(ps2port, DISABLE);
 321 }
 322
 323 /**
 324  * gscps2_probe() - Probes PS2 devices
 325  * @return: success/error report
 326  */
 327
 328 static int __init gscps2_probe(struct parisc_device *dev)
 329 {
 330         struct gscps2port *ps2port;
 331         struct serio *serio;
 332         unsigned long hpa = dev->hpa.start;
 333         int ret;
 334
 335         if (!dev->irq)
 336                 return -ENODEV;
 337
 338         /* Offset for DINO PS/2. Works with LASI even */
 339         if (dev->id.sversion == 0x96)
 340                 hpa += GSC_DINO_OFFSET;
 341
 342         ps2port = kzalloc(sizeof(struct gscps2port), GFP_KERNEL);
 343         serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
 344         if (!ps2port || !serio) {
 345                 ret = -ENOMEM;
 346                 goto fail_nomem;
 347         }
 348
 349         dev_set_drvdata(&dev->dev, ps2port);
 350
 351         ps2port->port = serio;
 352         ps2port->padev = dev;
 353         ps2port->addr = ioremap_nocache(hpa, GSC_STATUS + 4);
 354         spin_lock_init(&ps2port->lock);
 355
 356         gscps2_reset(ps2port);
 357         ps2port->id = readb(ps2port->addr + GSC_ID) & 0x0f;
 358
 359         snprintf(serio->name, sizeof(serio->name), "gsc-ps2-%s",
 360                  (ps2port->id == GSC_ID_KEYBOARD) ? "keyboard" : "mouse");
 361         strlcpy(serio->phys, dev_name(&dev->dev), sizeof(serio->phys));
 362         serio->id.type          = SERIO_8042;
 363         serio->write            = gscps2_write;
 364         serio->open             = gscps2_open;
 365         serio->close            = gscps2_close;
 366         serio->port_data        = ps2port;
 367         serio->dev.parent       = &dev->dev;
 368
 369         ret = -EBUSY;
 370         if (request_irq(dev->irq, gscps2_interrupt, IRQF_SHARED, ps2port->port->name, ps2port))
 371                 goto fail_miserably;
 372
 373         if (ps2port->id != GSC_ID_KEYBOARD && ps2port->id != GSC_ID_MOUSE) {
 374                 printk(KERN_WARNING PFX "Unsupported PS/2 port at 0x%08lx (id=%d) ignored\n",
 375                                 hpa, ps2port->id);
 376                 ret = -ENODEV;
 377                 goto fail;
 378         }
 379
 380 #if 0
 381         if (!request_mem_region(hpa, GSC_STATUS + 4, ps2port->port.name))
 382                 goto fail;
 383 #endif
 384
 385         printk(KERN_INFO "serio: %s port at 0x%p irq %d @ %s\n",
 386                 ps2port->port->name,
 387                 ps2port->addr,
 388                 ps2port->padev->irq,
 389                 ps2port->port->phys);
 390
 391         serio_register_port(ps2port->port);
 392
 393         list_add_tail(&ps2port->node, &ps2port_list);
 394
 395         return 0;
 396
 397 fail:
 398         free_irq(dev->irq, ps2port);
 399
 400 fail_miserably:
 401         iounmap(ps2port->addr);
 402         release_mem_region(dev->hpa.start, GSC_STATUS + 4);
 403
 404 fail_nomem:
 405         kfree(ps2port);
 406         kfree(serio);
 407         return ret;
 408 }
 409
 410 /**
 411  * gscps2_remove() - Removes PS2 devices
 412  * @return: success/error report
 413  */
 414
 415 static int __exit gscps2_remove(struct parisc_device *dev)
 416 {
 417         struct gscps2port *ps2port = dev_get_drvdata(&dev->dev);
 418
 419         serio_unregister_port(ps2port->port);
 420         free_irq(dev->irq, ps2port);
 421         gscps2_flush(ps2port);
 422         list_del(&ps2port->node);
 423         iounmap(ps2port->addr);
 424 #if 0
 425         release_mem_region(dev->hpa, GSC_STATUS + 4);
 426 #endif
 427         dev_set_drvdata(&dev->dev, NULL);
 428         kfree(ps2port);
 429         return 0;
 430 }
 431
 432
 433 static const struct parisc_device_id gscps2_device_tbl[] __initconst = {
 434         { HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00084 }, /* LASI PS/2 */
 435 #ifdef DINO_TESTED
 436         { HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00096 }, /* DINO PS/2 */
 437 #endif
 438         { 0, }  /* 0 terminated list */
 439 };
 440 MODULE_DEVICE_TABLE(parisc, gscps2_device_tbl);
 441
 442 static struct parisc_driver parisc_ps2_driver __refdata = {
 443         .name           = "gsc_ps2",
 444         .id_table       = gscps2_device_tbl,
 445         .probe          = gscps2_probe,
 446         .remove         = __exit_p(gscps2_remove),
 447 };
 448
 449 static int __init gscps2_init(void)
 450 {
 451         register_parisc_driver(&parisc_ps2_driver);
 452         return 0;
 453 }
 454
 455 static void __exit gscps2_exit(void)
 456 {
 457         unregister_parisc_driver(&parisc_ps2_driver);
 458 }
 459
 460
 461 module_init(gscps2_init);
 462 module_exit(gscps2_exit);
 463