drivers/tty/hvc/hvc_vio.c

   1 /*
   2  * vio driver interface to hvc_console.c
   3  *
   4  * This code was moved here to allow the remaining code to be reused as a
   5  * generic polling mode with semi-reliable transport driver core to the
   6  * console and tty subsystems.
   7  *
   8  *
   9  * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
  10  * Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM
  11  * Copyright (C) 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
  12  * Copyright (C) 2004 IBM Corporation
  13  *
  14  * Additional Author(s):
  15  *  Ryan S. Arnold <rsa@us.ibm.com>
  16  *
  17  * This program is free software; you can redistribute it and/or modify
  18  * it under the terms of the GNU General Public License as published by
  19  * the Free Software Foundation; either version 2 of the License, or
  20  * (at your option) any later version.
  21  *
  22  * This program is distributed in the hope that it will be useful,
  23  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  * GNU General Public License for more details.
  26  *
  27  * You should have received a copy of the GNU General Public License
  28  * along with this program; if not, write to the Free Software
  29  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  30  *
  31  * TODO:
  32  *
  33  *   - handle error in sending hvsi protocol packets
  34  *   - retry nego on subsequent sends ?
  35  */
  36
  37 #undef DEBUG
  38
  39 #include <linux/types.h>
  40 #include <linux/init.h>
  41 #include <linux/delay.h>
  42 #include <linux/slab.h>
  43 #include <linux/console.h>
  44
  45 #include <asm/hvconsole.h>
  46 #include <asm/vio.h>
  47 #include <asm/prom.h>
  48 #include <asm/firmware.h>
  49 #include <asm/hvsi.h>
  50 #include <asm/udbg.h>
  51
  52 #include "hvc_console.h"
  53
  54 static const char hvc_driver_name[] = "hvc_console";
  55
  56 static struct vio_device_id hvc_driver_table[] __devinitdata = {
  57         {"serial", "hvterm1"},
  58 #ifndef HVC_OLD_HVSI
  59         {"serial", "hvterm-protocol"},
  60 #endif
  61         { "", "" }
  62 };
  63 MODULE_DEVICE_TABLE(vio, hvc_driver_table);
  64
  65 typedef enum hv_protocol {
  66         HV_PROTOCOL_RAW,
  67         HV_PROTOCOL_HVSI
  68 } hv_protocol_t;
  69
  70 struct hvterm_priv {
  71         u32                     termno; /* HV term number */
  72         hv_protocol_t           proto;  /* Raw data or HVSI packets */
  73         struct hvsi_priv        hvsi;   /* HVSI specific data */
  74 };
  75 static struct hvterm_priv *hvterm_privs[MAX_NR_HVC_CONSOLES];
  76
  77 /* For early boot console */
  78 static struct hvterm_priv hvterm_priv0;
  79
  80 static int hvterm_raw_get_chars(uint32_t vtermno, char *buf, int count)
  81 {
  82         struct hvterm_priv *pv = hvterm_privs[vtermno];
  83         unsigned long got, i;
  84
  85         if (WARN_ON(!pv))
  86                 return 0;
  87
  88         /*
  89          * Vio firmware will read up to SIZE_VIO_GET_CHARS at its own discretion
  90          * so we play safe and avoid the situation where got > count which could
  91          * overload the flip buffer.
  92          */
  93         if (count < SIZE_VIO_GET_CHARS)
  94                 return -EAGAIN;
  95
  96         got = hvc_get_chars(pv->termno, buf, count);
  97
  98         /*
  99          * Work around a HV bug where it gives us a null
 100          * after every \r.  -- paulus
 101          */
 102         for (i = 1; i < got; ++i) {
 103                 if (buf[i] == 0 && buf[i-1] == '\r') {
 104                         --got;
 105                         if (i < got)
 106                                 memmove(&buf[i], &buf[i+1], got - i);
 107                 }
 108         }
 109         return got;
 110 }
 111
 112 static int hvterm_raw_put_chars(uint32_t vtermno, const char *buf, int count)
 113 {
 114         struct hvterm_priv *pv = hvterm_privs[vtermno];
 115
 116         if (WARN_ON(!pv))
 117                 return 0;
 118
 119         return hvc_put_chars(pv->termno, buf, count);
 120 }
 121
 122 static const struct hv_ops hvterm_raw_ops = {
 123         .get_chars = hvterm_raw_get_chars,
 124         .put_chars = hvterm_raw_put_chars,
 125         .notifier_add = notifier_add_irq,
 126         .notifier_del = notifier_del_irq,
 127         .notifier_hangup = notifier_hangup_irq,
 128 };
 129
 130 static int hvterm_hvsi_get_chars(uint32_t vtermno, char *buf, int count)
 131 {
 132         struct hvterm_priv *pv = hvterm_privs[vtermno];
 133
 134         if (WARN_ON(!pv))
 135                 return 0;
 136
 137         return hvsilib_get_chars(&pv->hvsi, buf, count);
 138 }
 139
 140 static int hvterm_hvsi_put_chars(uint32_t vtermno, const char *buf, int count)
 141 {
 142         struct hvterm_priv *pv = hvterm_privs[vtermno];
 143
 144         if (WARN_ON(!pv))
 145                 return 0;
 146
 147         return hvsilib_put_chars(&pv->hvsi, buf, count);
 148 }
 149
 150 static int hvterm_hvsi_open(struct hvc_struct *hp, int data)
 151 {
 152         struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
 153         int rc;
 154
 155         pr_devel("HVSI@%x: open !\n", pv->termno);
 156
 157         rc = notifier_add_irq(hp, data);
 158         if (rc)
 159                 return rc;
 160
 161         return hvsilib_open(&pv->hvsi, hp);
 162 }
 163
 164 static void hvterm_hvsi_close(struct hvc_struct *hp, int data)
 165 {
 166         struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
 167
 168         pr_devel("HVSI@%x: do close !\n", pv->termno);
 169
 170         hvsilib_close(&pv->hvsi, hp);
 171
 172         notifier_del_irq(hp, data);
 173 }
 174
 175 void hvterm_hvsi_hangup(struct hvc_struct *hp, int data)
 176 {
 177         struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
 178
 179         pr_devel("HVSI@%x: do hangup !\n", pv->termno);
 180
 181         hvsilib_close(&pv->hvsi, hp);
 182
 183         notifier_hangup_irq(hp, data);
 184 }
 185
 186 static int hvterm_hvsi_tiocmget(struct hvc_struct *hp)
 187 {
 188         struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
 189
 190         if (!pv)
 191                 return -EINVAL;
 192         return pv->hvsi.mctrl;
 193 }
 194
 195 static int hvterm_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
 196                                 unsigned int clear)
 197 {
 198         struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
 199
 200         pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
 201                  pv->termno, set, clear);
 202
 203         if (set & TIOCM_DTR)
 204                 hvsilib_write_mctrl(&pv->hvsi, 1);
 205         else if (clear & TIOCM_DTR)
 206                 hvsilib_write_mctrl(&pv->hvsi, 0);
 207
 208         return 0;
 209 }
 210
 211 static const struct hv_ops hvterm_hvsi_ops = {
 212         .get_chars = hvterm_hvsi_get_chars,
 213         .put_chars = hvterm_hvsi_put_chars,
 214         .notifier_add = hvterm_hvsi_open,
 215         .notifier_del = hvterm_hvsi_close,
 216         .notifier_hangup = hvterm_hvsi_hangup,
 217         .tiocmget = hvterm_hvsi_tiocmget,
 218         .tiocmset = hvterm_hvsi_tiocmset,
 219 };
 220
 221 static int __devinit hvc_vio_probe(struct vio_dev *vdev,
 222                                    const struct vio_device_id *id)
 223 {
 224         const struct hv_ops *ops;
 225         struct hvc_struct *hp;
 226         struct hvterm_priv *pv;
 227         hv_protocol_t proto;
 228         int i, termno = -1;
 229
 230         /* probed with invalid parameters. */
 231         if (!vdev || !id)
 232                 return -EPERM;
 233
 234         if (of_device_is_compatible(vdev->dev.of_node, "hvterm1")) {
 235                 proto = HV_PROTOCOL_RAW;
 236                 ops = &hvterm_raw_ops;
 237         } else if (of_device_is_compatible(vdev->dev.of_node, "hvterm-protocol")) {
 238                 proto = HV_PROTOCOL_HVSI;
 239                 ops = &hvterm_hvsi_ops;
 240         } else {
 241                 pr_err("hvc_vio: Unkown protocol for %s\n", vdev->dev.of_node->full_name);
 242                 return -ENXIO;
 243         }
 244
 245         pr_devel("hvc_vio_probe() device %s, using %s protocol\n",
 246                  vdev->dev.of_node->full_name,
 247                  proto == HV_PROTOCOL_RAW ? "raw" : "hvsi");
 248
 249         /* Is it our boot one ? */
 250         if (hvterm_privs[0] == &hvterm_priv0 &&
 251             vdev->unit_address == hvterm_priv0.termno) {
 252                 pv = hvterm_privs[0];
 253                 termno = 0;
 254                 pr_devel("->boot console, using termno 0\n");
 255         }
 256         /* nope, allocate a new one */
 257         else {
 258                 for (i = 0; i < MAX_NR_HVC_CONSOLES && termno < 0; i++)
 259                         if (!hvterm_privs[i])
 260                                 termno = i;
 261                 pr_devel("->non-boot console, using termno %d\n", termno);
 262                 if (termno < 0)
 263                         return -ENODEV;
 264                 pv = kzalloc(sizeof(struct hvterm_priv), GFP_KERNEL);
 265                 if (!pv)
 266                         return -ENOMEM;
 267                 pv->termno = vdev->unit_address;
 268                 pv->proto = proto;
 269                 hvterm_privs[termno] = pv;
 270                 hvsilib_init(&pv->hvsi, hvc_get_chars, hvc_put_chars,
 271                              pv->termno, 0);
 272         }
 273
 274         hp = hvc_alloc(termno, vdev->irq, ops, MAX_VIO_PUT_CHARS);
 275         if (IS_ERR(hp))
 276                 return PTR_ERR(hp);
 277         dev_set_drvdata(&vdev->dev, hp);
 278
 279         return 0;
 280 }
 281
 282 static int __devexit hvc_vio_remove(struct vio_dev *vdev)
 283 {
 284         struct hvc_struct *hp = dev_get_drvdata(&vdev->dev);
 285         int rc, termno;
 286
 287         termno = hp->vtermno;
 288         rc = hvc_remove(hp);
 289         if (rc == 0) {
 290                 if (hvterm_privs[termno] != &hvterm_priv0)
 291                         kfree(hvterm_privs[termno]);
 292                 hvterm_privs[termno] = NULL;
 293         }
 294         return rc;
 295 }
 296
 297 static struct vio_driver hvc_vio_driver = {
 298         .id_table       = hvc_driver_table,
 299         .probe          = hvc_vio_probe,
 300         .remove         = __devexit_p(hvc_vio_remove),
 301         .driver         = {
 302                 .name   = hvc_driver_name,
 303                 .owner  = THIS_MODULE,
 304         }
 305 };
 306
 307 static int __init hvc_vio_init(void)
 308 {
 309         int rc;
 310
 311         if (firmware_has_feature(FW_FEATURE_ISERIES))
 312                 return -EIO;
 313
 314         /* Register as a vio device to receive callbacks */
 315         rc = vio_register_driver(&hvc_vio_driver);
 316
 317         return rc;
 318 }
 319 module_init(hvc_vio_init); /* after drivers/char/hvc_console.c */
 320
 321 static void __exit hvc_vio_exit(void)
 322 {
 323         vio_unregister_driver(&hvc_vio_driver);
 324 }
 325 module_exit(hvc_vio_exit);
 326
 327 static void udbg_hvc_putc(char c)
 328 {
 329         int count = -1;
 330
 331         if (c == '\n')
 332                 udbg_hvc_putc('\r');
 333
 334         do {
 335                 switch(hvterm_priv0.proto) {
 336                 case HV_PROTOCOL_RAW:
 337                         count = hvterm_raw_put_chars(0, &c, 1);
 338                         break;
 339                 case HV_PROTOCOL_HVSI:
 340                         count = hvterm_hvsi_put_chars(0, &c, 1);
 341                         break;
 342                 }
 343         } while(count == 0);
 344 }
 345
 346 static int udbg_hvc_getc_poll(void)
 347 {
 348         int rc = 0;
 349         char c;
 350
 351         switch(hvterm_priv0.proto) {
 352         case HV_PROTOCOL_RAW:
 353                 rc = hvterm_raw_get_chars(0, &c, 1);
 354                 break;
 355         case HV_PROTOCOL_HVSI:
 356                 rc = hvterm_hvsi_get_chars(0, &c, 1);
 357                 break;
 358         }
 359         if (!rc)
 360                 return -1;
 361         return c;
 362 }
 363
 364 static int udbg_hvc_getc(void)
 365 {
 366         int ch;
 367         for (;;) {
 368                 ch = udbg_hvc_getc_poll();
 369                 if (ch == -1) {
 370                         /* This shouldn't be needed...but... */
 371                         volatile unsigned long delay;
 372                         for (delay=0; delay < 2000000; delay++)
 373                                 ;
 374                 } else {
 375                         return ch;
 376                 }
 377         }
 378 }
 379
 380 void __init hvc_vio_init_early(void)
 381 {
 382         struct device_node *stdout_node;
 383         const u32 *termno;
 384         const char *name;
 385         const struct hv_ops *ops;
 386
 387         /* find the boot console from /chosen/stdout */
 388         if (!of_chosen)
 389                 return;
 390         name = of_get_property(of_chosen, "linux,stdout-path", NULL);
 391         if (name == NULL)
 392                 return;
 393         stdout_node = of_find_node_by_path(name);
 394         if (!stdout_node)
 395                 return;
 396         name = of_get_property(stdout_node, "name", NULL);
 397         if (!name) {
 398                 printk(KERN_WARNING "stdout node missing 'name' property!\n");
 399                 goto out;
 400         }
 401
 402         /* Check if it's a virtual terminal */
 403         if (strncmp(name, "vty", 3) != 0)
 404                 goto out;
 405         termno = of_get_property(stdout_node, "reg", NULL);
 406         if (termno == NULL)
 407                 goto out;
 408         hvterm_priv0.termno = *termno;
 409         hvterm_privs[0] = &hvterm_priv0;
 410
 411         /* Check the protocol */
 412         if (of_device_is_compatible(stdout_node, "hvterm1")) {
 413                 hvterm_priv0.proto = HV_PROTOCOL_RAW;
 414                 ops = &hvterm_raw_ops;
 415         }
 416         else if (of_device_is_compatible(stdout_node, "hvterm-protocol")) {
 417                 hvterm_priv0.proto = HV_PROTOCOL_HVSI;
 418                 ops = &hvterm_hvsi_ops;
 419                 hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
 420                              hvterm_priv0.termno, 1);
 421                 /* HVSI, perform the handshake now */
 422                 hvsilib_establish(&hvterm_priv0.hvsi);
 423         } else
 424                 goto out;
 425         udbg_putc = udbg_hvc_putc;
 426         udbg_getc = udbg_hvc_getc;
 427         udbg_getc_poll = udbg_hvc_getc_poll;
 428 #ifdef HVC_OLD_HVSI
 429         /* When using the old HVSI driver don't register the HVC
 430          * backend for HVSI, only do udbg
 431          */
 432         if (hvterm_priv0.proto == HV_PROTOCOL_HVSI)
 433                 goto out;
 434 #endif
 435         add_preferred_console("hvc", 0, NULL);
 436         hvc_instantiate(0, 0, ops);
 437 out:
 438         of_node_put(stdout_node);
 439 }
 440
 441 /* call this from early_init() for a working debug console on
 442  * vterm capable LPAR machines
 443  */
 444 #ifdef CONFIG_PPC_EARLY_DEBUG_LPAR
 445 void __init udbg_init_debug_lpar(void)
 446 {
 447         hvterm_privs[0] = &hvterm_priv0;
 448         hvterm_priv0.termno = 0;
 449         hvterm_priv0.proto = HV_PROTOCOL_RAW;
 450         udbg_putc = udbg_hvc_putc;
 451         udbg_getc = udbg_hvc_getc;
 452         udbg_getc_poll = udbg_hvc_getc_poll;
 453 }
 454 #endif /* CONFIG_PPC_EARLY_DEBUG_LPAR */
 455
 456 #ifdef CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI
 457 void __init udbg_init_debug_lpar_hvsi(void)
 458 {
 459         hvterm_privs[0] = &hvterm_priv0;
 460         hvterm_priv0.termno = CONFIG_PPC_EARLY_DEBUG_HVSI_VTERMNO;
 461         hvterm_priv0.proto = HV_PROTOCOL_HVSI;
 462         udbg_putc = udbg_hvc_putc;
 463         udbg_getc = udbg_hvc_getc;
 464         udbg_getc_poll = udbg_hvc_getc_poll;
 465         hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
 466                      hvterm_priv0.termno, 1);
 467         hvsilib_establish(&hvterm_priv0.hvsi);
 468 }
 469 #endif /* CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI */