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 #include <linux/module.h>
  45
  46 #include <asm/hvconsole.h>
  47 #include <asm/vio.h>
  48 #include <asm/prom.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[] = {
  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         spinlock_t              buf_lock;
  75         char                    buf[SIZE_VIO_GET_CHARS];
  76         int                     left;
  77         int                     offset;
  78 };
  79 static struct hvterm_priv *hvterm_privs[MAX_NR_HVC_CONSOLES];
  80 /* For early boot console */
  81 static struct hvterm_priv hvterm_priv0;
  82
  83 static int hvterm_raw_get_chars(uint32_t vtermno, char *buf, int count)
  84 {
  85         struct hvterm_priv *pv = hvterm_privs[vtermno];
  86         unsigned long i;
  87         unsigned long flags;
  88         int got;
  89
  90         if (WARN_ON(!pv))
  91                 return 0;
  92
  93         spin_lock_irqsave(&pv->buf_lock, flags);
  94
  95         if (pv->left == 0) {
  96                 pv->offset = 0;
  97                 pv->left = hvc_get_chars(pv->termno, pv->buf, count);
  98
  99                 /*
 100                  * Work around a HV bug where it gives us a null
 101                  * after every \r.  -- paulus
 102                  */
 103                 for (i = 1; i < pv->left; ++i) {
 104                         if (pv->buf[i] == 0 && pv->buf[i-1] == '\r') {
 105                                 --pv->left;
 106                                 if (i < pv->left) {
 107                                         memmove(&pv->buf[i], &pv->buf[i+1],
 108                                                 pv->left - i);
 109                                 }
 110                         }
 111                 }
 112         }
 113
 114         got = min(count, pv->left);
 115         memcpy(buf, &pv->buf[pv->offset], got);
 116         pv->offset += got;
 117         pv->left -= got;
 118
 119         spin_unlock_irqrestore(&pv->buf_lock, flags);
 120
 121         return got;
 122 }
 123
 124 static int hvterm_raw_put_chars(uint32_t vtermno, const char *buf, int count)
 125 {
 126         struct hvterm_priv *pv = hvterm_privs[vtermno];
 127
 128         if (WARN_ON(!pv))
 129                 return 0;
 130
 131         return hvc_put_chars(pv->termno, buf, count);
 132 }
 133
 134 static const struct hv_ops hvterm_raw_ops = {
 135         .get_chars = hvterm_raw_get_chars,
 136         .put_chars = hvterm_raw_put_chars,
 137         .notifier_add = notifier_add_irq,
 138         .notifier_del = notifier_del_irq,
 139         .notifier_hangup = notifier_hangup_irq,
 140 };
 141
 142 static int hvterm_hvsi_get_chars(uint32_t vtermno, char *buf, int count)
 143 {
 144         struct hvterm_priv *pv = hvterm_privs[vtermno];
 145
 146         if (WARN_ON(!pv))
 147                 return 0;
 148
 149         return hvsilib_get_chars(&pv->hvsi, buf, count);
 150 }
 151
 152 static int hvterm_hvsi_put_chars(uint32_t vtermno, const char *buf, int count)
 153 {
 154         struct hvterm_priv *pv = hvterm_privs[vtermno];
 155
 156         if (WARN_ON(!pv))
 157                 return 0;
 158
 159         return hvsilib_put_chars(&pv->hvsi, buf, count);
 160 }
 161
 162 static int hvterm_hvsi_open(struct hvc_struct *hp, int data)
 163 {
 164         struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
 165         int rc;
 166
 167         pr_devel("HVSI@%x: open !\n", pv->termno);
 168
 169         rc = notifier_add_irq(hp, data);
 170         if (rc)
 171                 return rc;
 172
 173         return hvsilib_open(&pv->hvsi, hp);
 174 }
 175
 176 static void hvterm_hvsi_close(struct hvc_struct *hp, int data)
 177 {
 178         struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
 179
 180         pr_devel("HVSI@%x: do close !\n", pv->termno);
 181
 182         hvsilib_close(&pv->hvsi, hp);
 183
 184         notifier_del_irq(hp, data);
 185 }
 186
 187 void hvterm_hvsi_hangup(struct hvc_struct *hp, int data)
 188 {
 189         struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
 190
 191         pr_devel("HVSI@%x: do hangup !\n", pv->termno);
 192
 193         hvsilib_close(&pv->hvsi, hp);
 194
 195         notifier_hangup_irq(hp, data);
 196 }
 197
 198 static int hvterm_hvsi_tiocmget(struct hvc_struct *hp)
 199 {
 200         struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
 201
 202         if (!pv)
 203                 return -EINVAL;
 204         return pv->hvsi.mctrl;
 205 }
 206
 207 static int hvterm_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
 208                                 unsigned int clear)
 209 {
 210         struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
 211
 212         pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
 213                  pv->termno, set, clear);
 214
 215         if (set & TIOCM_DTR)
 216                 hvsilib_write_mctrl(&pv->hvsi, 1);
 217         else if (clear & TIOCM_DTR)
 218                 hvsilib_write_mctrl(&pv->hvsi, 0);
 219
 220         return 0;
 221 }
 222
 223 static const struct hv_ops hvterm_hvsi_ops = {
 224         .get_chars = hvterm_hvsi_get_chars,
 225         .put_chars = hvterm_hvsi_put_chars,
 226         .notifier_add = hvterm_hvsi_open,
 227         .notifier_del = hvterm_hvsi_close,
 228         .notifier_hangup = hvterm_hvsi_hangup,
 229         .tiocmget = hvterm_hvsi_tiocmget,
 230         .tiocmset = hvterm_hvsi_tiocmset,
 231 };
 232
 233 static void udbg_hvc_putc(char c)
 234 {
 235         int count = -1;
 236
 237         if (!hvterm_privs[0])
 238                 return;
 239
 240         if (c == '\n')
 241                 udbg_hvc_putc('\r');
 242
 243         do {
 244                 switch(hvterm_privs[0]->proto) {
 245                 case HV_PROTOCOL_RAW:
 246                         count = hvterm_raw_put_chars(0, &c, 1);
 247                         break;
 248                 case HV_PROTOCOL_HVSI:
 249                         count = hvterm_hvsi_put_chars(0, &c, 1);
 250                         break;
 251                 }
 252         } while(count == 0);
 253 }
 254
 255 static int udbg_hvc_getc_poll(void)
 256 {
 257         int rc = 0;
 258         char c;
 259
 260         if (!hvterm_privs[0])
 261                 return -1;
 262
 263         switch(hvterm_privs[0]->proto) {
 264         case HV_PROTOCOL_RAW:
 265                 rc = hvterm_raw_get_chars(0, &c, 1);
 266                 break;
 267         case HV_PROTOCOL_HVSI:
 268                 rc = hvterm_hvsi_get_chars(0, &c, 1);
 269                 break;
 270         }
 271         if (!rc)
 272                 return -1;
 273         return c;
 274 }
 275
 276 static int udbg_hvc_getc(void)
 277 {
 278         int ch;
 279
 280         if (!hvterm_privs[0])
 281                 return -1;
 282
 283         for (;;) {
 284                 ch = udbg_hvc_getc_poll();
 285                 if (ch == -1) {
 286                         /* This shouldn't be needed...but... */
 287                         volatile unsigned long delay;
 288                         for (delay=0; delay < 2000000; delay++)
 289                                 ;
 290                 } else {
 291                         return ch;
 292                 }
 293         }
 294 }
 295
 296 static int hvc_vio_probe(struct vio_dev *vdev,
 297                                    const struct vio_device_id *id)
 298 {
 299         const struct hv_ops *ops;
 300         struct hvc_struct *hp;
 301         struct hvterm_priv *pv;
 302         hv_protocol_t proto;
 303         int i, termno = -1;
 304
 305         /* probed with invalid parameters. */
 306         if (!vdev || !id)
 307                 return -EPERM;
 308
 309         if (of_device_is_compatible(vdev->dev.of_node, "hvterm1")) {
 310                 proto = HV_PROTOCOL_RAW;
 311                 ops = &hvterm_raw_ops;
 312         } else if (of_device_is_compatible(vdev->dev.of_node, "hvterm-protocol")) {
 313                 proto = HV_PROTOCOL_HVSI;
 314                 ops = &hvterm_hvsi_ops;
 315         } else {
 316                 pr_err("hvc_vio: Unknown protocol for %s\n", vdev->dev.of_node->full_name);
 317                 return -ENXIO;
 318         }
 319
 320         pr_devel("hvc_vio_probe() device %s, using %s protocol\n",
 321                  vdev->dev.of_node->full_name,
 322                  proto == HV_PROTOCOL_RAW ? "raw" : "hvsi");
 323
 324         /* Is it our boot one ? */
 325         if (hvterm_privs[0] == &hvterm_priv0 &&
 326             vdev->unit_address == hvterm_priv0.termno) {
 327                 pv = hvterm_privs[0];
 328                 termno = 0;
 329                 pr_devel("->boot console, using termno 0\n");
 330         }
 331         /* nope, allocate a new one */
 332         else {
 333                 for (i = 0; i < MAX_NR_HVC_CONSOLES && termno < 0; i++)
 334                         if (!hvterm_privs[i])
 335                                 termno = i;
 336                 pr_devel("->non-boot console, using termno %d\n", termno);
 337                 if (termno < 0)
 338                         return -ENODEV;
 339                 pv = kzalloc(sizeof(struct hvterm_priv), GFP_KERNEL);
 340                 if (!pv)
 341                         return -ENOMEM;
 342                 pv->termno = vdev->unit_address;
 343                 pv->proto = proto;
 344                 spin_lock_init(&pv->buf_lock);
 345                 hvterm_privs[termno] = pv;
 346                 hvsilib_init(&pv->hvsi, hvc_get_chars, hvc_put_chars,
 347                              pv->termno, 0);
 348         }
 349
 350         hp = hvc_alloc(termno, vdev->irq, ops, MAX_VIO_PUT_CHARS);
 351         if (IS_ERR(hp))
 352                 return PTR_ERR(hp);
 353         dev_set_drvdata(&vdev->dev, hp);
 354
 355         /* register udbg if it's not there already for console 0 */
 356         if (hp->index == 0 && !udbg_putc) {
 357                 udbg_putc = udbg_hvc_putc;
 358                 udbg_getc = udbg_hvc_getc;
 359                 udbg_getc_poll = udbg_hvc_getc_poll;
 360         }
 361
 362         return 0;
 363 }
 364
 365 static int hvc_vio_remove(struct vio_dev *vdev)
 366 {
 367         struct hvc_struct *hp = dev_get_drvdata(&vdev->dev);
 368         int rc, termno;
 369
 370         termno = hp->vtermno;
 371         rc = hvc_remove(hp);
 372         if (rc == 0) {
 373                 if (hvterm_privs[termno] != &hvterm_priv0)
 374                         kfree(hvterm_privs[termno]);
 375                 hvterm_privs[termno] = NULL;
 376         }
 377         return rc;
 378 }
 379
 380 static struct vio_driver hvc_vio_driver = {
 381         .id_table       = hvc_driver_table,
 382         .probe          = hvc_vio_probe,
 383         .remove         = hvc_vio_remove,
 384         .name           = hvc_driver_name,
 385 };
 386
 387 static int __init hvc_vio_init(void)
 388 {
 389         int rc;
 390
 391         /* Register as a vio device to receive callbacks */
 392         rc = vio_register_driver(&hvc_vio_driver);
 393
 394         return rc;
 395 }
 396 module_init(hvc_vio_init); /* after drivers/char/hvc_console.c */
 397
 398 static void __exit hvc_vio_exit(void)
 399 {
 400         vio_unregister_driver(&hvc_vio_driver);
 401 }
 402 module_exit(hvc_vio_exit);
 403
 404 void __init hvc_vio_init_early(void)
 405 {
 406         struct device_node *stdout_node;
 407         const u32 *termno;
 408         const char *name;
 409         const struct hv_ops *ops;
 410
 411         /* find the boot console from /chosen/stdout */
 412         if (!of_chosen)
 413                 return;
 414         name = of_get_property(of_chosen, "linux,stdout-path", NULL);
 415         if (name == NULL)
 416                 return;
 417         stdout_node = of_find_node_by_path(name);
 418         if (!stdout_node)
 419                 return;
 420         name = of_get_property(stdout_node, "name", NULL);
 421         if (!name) {
 422                 printk(KERN_WARNING "stdout node missing 'name' property!\n");
 423                 goto out;
 424         }
 425
 426         /* Check if it's a virtual terminal */
 427         if (strncmp(name, "vty", 3) != 0)
 428                 goto out;
 429         termno = of_get_property(stdout_node, "reg", NULL);
 430         if (termno == NULL)
 431                 goto out;
 432         hvterm_priv0.termno = *termno;
 433         spin_lock_init(&hvterm_priv0.buf_lock);
 434         hvterm_privs[0] = &hvterm_priv0;
 435
 436         /* Check the protocol */
 437         if (of_device_is_compatible(stdout_node, "hvterm1")) {
 438                 hvterm_priv0.proto = HV_PROTOCOL_RAW;
 439                 ops = &hvterm_raw_ops;
 440         }
 441         else if (of_device_is_compatible(stdout_node, "hvterm-protocol")) {
 442                 hvterm_priv0.proto = HV_PROTOCOL_HVSI;
 443                 ops = &hvterm_hvsi_ops;
 444                 hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
 445                              hvterm_priv0.termno, 1);
 446                 /* HVSI, perform the handshake now */
 447                 hvsilib_establish(&hvterm_priv0.hvsi);
 448         } else
 449                 goto out;
 450         udbg_putc = udbg_hvc_putc;
 451         udbg_getc = udbg_hvc_getc;
 452         udbg_getc_poll = udbg_hvc_getc_poll;
 453 #ifdef HVC_OLD_HVSI
 454         /* When using the old HVSI driver don't register the HVC
 455          * backend for HVSI, only do udbg
 456          */
 457         if (hvterm_priv0.proto == HV_PROTOCOL_HVSI)
 458                 goto out;
 459 #endif
 460         add_preferred_console("hvc", 0, NULL);
 461         hvc_instantiate(0, 0, ops);
 462 out:
 463         of_node_put(stdout_node);
 464 }
 465
 466 /* call this from early_init() for a working debug console on
 467  * vterm capable LPAR machines
 468  */
 469 #ifdef CONFIG_PPC_EARLY_DEBUG_LPAR
 470 void __init udbg_init_debug_lpar(void)
 471 {
 472         hvterm_privs[0] = &hvterm_priv0;
 473         hvterm_priv0.termno = 0;
 474         hvterm_priv0.proto = HV_PROTOCOL_RAW;
 475         spin_lock_init(&hvterm_priv0.buf_lock);
 476         udbg_putc = udbg_hvc_putc;
 477         udbg_getc = udbg_hvc_getc;
 478         udbg_getc_poll = udbg_hvc_getc_poll;
 479 }
 480 #endif /* CONFIG_PPC_EARLY_DEBUG_LPAR */
 481
 482 #ifdef CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI
 483 void __init udbg_init_debug_lpar_hvsi(void)
 484 {
 485         hvterm_privs[0] = &hvterm_priv0;
 486         hvterm_priv0.termno = CONFIG_PPC_EARLY_DEBUG_HVSI_VTERMNO;
 487         hvterm_priv0.proto = HV_PROTOCOL_HVSI;
 488         spin_lock_init(&hvterm_priv0.buf_lock);
 489         udbg_putc = udbg_hvc_putc;
 490         udbg_getc = udbg_hvc_getc;
 491         udbg_getc_poll = udbg_hvc_getc_poll;
 492         hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
 493                      hvterm_priv0.termno, 1);
 494         hvsilib_establish(&hvterm_priv0.hvsi);
 495 }
 496 #endif /* CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI */