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 __iomem *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 __iomem *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 __iomem *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(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         unsigned long flags;
 204
 205         /* reset the interface */
 206         spin_lock_irqsave(&ps2port->lock, flags);
 207         gscps2_flush(ps2port);
 208         writeb(0xff, ps2port->addr + GSC_RESET);
 209         gscps2_flush(ps2port);
 210         spin_unlock_irqrestore(&ps2port->lock, flags);
 211 }
 212
 213 static LIST_HEAD(ps2port_list);
 214
 215 /**
 216  * gscps2_interrupt() - Interruption service routine
 217  *
 218  * This function reads received PS/2 bytes and processes them on
 219  * all interfaces.
 220  * The problematic part here is, that the keyboard and mouse PS/2 port
 221  * share the same interrupt and it's not possible to send data if any
 222  * one of them holds input data. To solve this problem we try to receive
 223  * the data as fast as possible and handle the reporting to the upper layer
 224  * later.
 225  */
 226
 227 static irqreturn_t gscps2_interrupt(int irq, void *dev)
 228 {
 229         struct gscps2port *ps2port;
 230
 231         list_for_each_entry(ps2port, &ps2port_list, node) {
 232
 233           unsigned long flags;
 234           spin_lock_irqsave(&ps2port->lock, flags);
 235
 236           while ( (ps2port->buffer[ps2port->append].str =
 237                    gscps2_readb_status(ps2port->addr)) & GSC_STAT_RBNE ) {
 238                 ps2port->buffer[ps2port->append].data =
 239                                 gscps2_readb_input(ps2port->addr);
 240                 ps2port->append = ((ps2port->append+1) & BUFFER_SIZE);
 241           }
 242
 243           spin_unlock_irqrestore(&ps2port->lock, flags);
 244
 245         } /* list_for_each_entry */
 246
 247         /* all data was read from the ports - now report the data to upper layer */
 248
 249         list_for_each_entry(ps2port, &ps2port_list, node) {
 250
 251           while (ps2port->act != ps2port->append) {
 252
 253             unsigned int rxflags;
 254             u8 data, status;
 255
 256             /* Did new data arrived while we read existing data ?
 257                If yes, exit now and let the new irq handler start over again */
 258             if (gscps2_readb_status(ps2port->addr) & GSC_STAT_CMPINTR)
 259                 return IRQ_HANDLED;
 260
 261             status = ps2port->buffer[ps2port->act].str;
 262             data   = ps2port->buffer[ps2port->act].data;
 263
 264             ps2port->act = ((ps2port->act+1) & BUFFER_SIZE);
 265             rxflags =   ((status & GSC_STAT_TERR) ? SERIO_TIMEOUT : 0 ) |
 266                         ((status & GSC_STAT_PERR) ? SERIO_PARITY  : 0 );
 267
 268             serio_interrupt(ps2port->port, data, rxflags);
 269
 270           } /* while() */
 271
 272         } /* list_for_each_entry */
 273
 274         return IRQ_HANDLED;
 275 }
 276
 277
 278 /*
 279  * gscps2_write() - send a byte out through the aux interface.
 280  */
 281
 282 static int gscps2_write(struct serio *port, unsigned char data)
 283 {
 284         struct gscps2port *ps2port = port->port_data;
 285
 286         if (!gscps2_writeb_output(ps2port, data)) {
 287                 printk(KERN_DEBUG PFX "sending byte %#x failed.\n", data);
 288                 return -1;
 289         }
 290         return 0;
 291 }
 292
 293 /*
 294  * gscps2_open() is called when a port is opened by the higher layer.
 295  * It resets and enables the port.
 296  */
 297
 298 static int gscps2_open(struct serio *port)
 299 {
 300         struct gscps2port *ps2port = port->port_data;
 301
 302         gscps2_reset(ps2port);
 303
 304         /* enable it */
 305         gscps2_enable(ps2port, ENABLE);
 306
 307         gscps2_interrupt(0, NULL);
 308
 309         return 0;
 310 }
 311
 312 /*
 313  * gscps2_close() disables the port
 314  */
 315
 316 static void gscps2_close(struct serio *port)
 317 {
 318         struct gscps2port *ps2port = port->port_data;
 319         gscps2_enable(ps2port, DISABLE);
 320 }
 321
 322 /**
 323  * gscps2_probe() - Probes PS2 devices
 324  * @return: success/error report
 325  */
 326
 327 static int __init gscps2_probe(struct parisc_device *dev)
 328 {
 329         struct gscps2port *ps2port;
 330         struct serio *serio;
 331         unsigned long hpa = dev->hpa.start;
 332         int ret;
 333
 334         if (!dev->irq)
 335                 return -ENODEV;
 336
 337         /* Offset for DINO PS/2. Works with LASI even */
 338         if (dev->id.sversion == 0x96)
 339                 hpa += GSC_DINO_OFFSET;
 340
 341         ps2port = kzalloc(sizeof(struct gscps2port), GFP_KERNEL);
 342         serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
 343         if (!ps2port || !serio) {
 344                 ret = -ENOMEM;
 345                 goto fail_nomem;
 346         }
 347
 348         dev_set_drvdata(&dev->dev, ps2port);
 349
 350         ps2port->port = serio;
 351         ps2port->padev = dev;
 352         ps2port->addr = ioremap(hpa, GSC_STATUS + 4);
 353         spin_lock_init(&ps2port->lock);
 354
 355         gscps2_reset(ps2port);
 356         ps2port->id = readb(ps2port->addr + GSC_ID) & 0x0f;
 357
 358         snprintf(serio->name, sizeof(serio->name), "gsc-ps2-%s",
 359                  (ps2port->id == GSC_ID_KEYBOARD) ? "keyboard" : "mouse");
 360         strlcpy(serio->phys, dev_name(&dev->dev), sizeof(serio->phys));
 361         serio->id.type          = SERIO_8042;
 362         serio->write            = gscps2_write;
 363         serio->open             = gscps2_open;
 364         serio->close            = gscps2_close;
 365         serio->port_data        = ps2port;
 366         serio->dev.parent       = &dev->dev;
 367
 368         ret = -EBUSY;
 369         if (request_irq(dev->irq, gscps2_interrupt, IRQF_SHARED, ps2port->port->name, ps2port))
 370                 goto fail_miserably;
 371
 372         if (ps2port->id != GSC_ID_KEYBOARD && ps2port->id != GSC_ID_MOUSE) {
 373                 printk(KERN_WARNING PFX "Unsupported PS/2 port at 0x%08lx (id=%d) ignored\n",
 374                                 hpa, ps2port->id);
 375                 ret = -ENODEV;
 376                 goto fail;
 377         }
 378
 379 #if 0
 380         if (!request_mem_region(hpa, GSC_STATUS + 4, ps2port->port.name))
 381                 goto fail;
 382 #endif
 383
 384         pr_info("serio: %s port at 0x%08lx irq %d @ %s\n",
 385                 ps2port->port->name,
 386                 hpa,
 387                 ps2port->padev->irq,
 388                 ps2port->port->phys);
 389
 390         serio_register_port(ps2port->port);
 391
 392         list_add_tail(&ps2port->node, &ps2port_list);
 393
 394         return 0;
 395
 396 fail:
 397         free_irq(dev->irq, ps2port);
 398
 399 fail_miserably:
 400         iounmap(ps2port->addr);
 401         release_mem_region(dev->hpa.start, GSC_STATUS + 4);
 402
 403 fail_nomem:
 404         kfree(ps2port);
 405         kfree(serio);
 406         return ret;
 407 }
 408
 409 /**
 410  * gscps2_remove() - Removes PS2 devices
 411  * @return: success/error report
 412  */
 413
 414 static int __exit gscps2_remove(struct parisc_device *dev)
 415 {
 416         struct gscps2port *ps2port = dev_get_drvdata(&dev->dev);
 417
 418         serio_unregister_port(ps2port->port);
 419         free_irq(dev->irq, ps2port);
 420         gscps2_flush(ps2port);
 421         list_del(&ps2port->node);
 422         iounmap(ps2port->addr);
 423 #if 0
 424         release_mem_region(dev->hpa, GSC_STATUS + 4);
 425 #endif
 426         dev_set_drvdata(&dev->dev, NULL);
 427         kfree(ps2port);
 428         return 0;
 429 }
 430
 431
 432 static const struct parisc_device_id gscps2_device_tbl[] __initconst = {
 433         { HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00084 }, /* LASI PS/2 */
 434 #ifdef DINO_TESTED
 435         { HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00096 }, /* DINO PS/2 */
 436 #endif
 437         { 0, }  /* 0 terminated list */
 438 };
 439 MODULE_DEVICE_TABLE(parisc, gscps2_device_tbl);
 440
 441 static struct parisc_driver parisc_ps2_driver __refdata = {
 442         .name           = "gsc_ps2",
 443         .id_table       = gscps2_device_tbl,
 444         .probe          = gscps2_probe,
 445         .remove         = __exit_p(gscps2_remove),
 446 };
 447
 448 static int __init gscps2_init(void)
 449 {
 450         register_parisc_driver(&parisc_ps2_driver);
 451         return 0;
 452 }
 453
 454 static void __exit gscps2_exit(void)
 455 {
 456         unregister_parisc_driver(&parisc_ps2_driver);
 457 }
 458
 459
 460 module_init(gscps2_init);
 461 module_exit(gscps2_exit);
 462