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 #include <asm/machdep.h>
  52
  53 #include "hvc_console.h"
  54
  55 static const char hvc_driver_name[] = "hvc_console";
  56
  57 static struct vio_device_id hvc_driver_table[] = {
  58         {"serial", "hvterm1"},
  59 #ifndef HVC_OLD_HVSI
  60         {"serial", "hvterm-protocol"},
  61 #endif
  62         { "", "" }
  63 };
  64 MODULE_DEVICE_TABLE(vio, hvc_driver_table);
  65
  66 typedef enum hv_protocol {
  67         HV_PROTOCOL_RAW,
  68         HV_PROTOCOL_HVSI
  69 } hv_protocol_t;
  70
  71 struct hvterm_priv {
  72         u32                     termno; /* HV term number */
  73         hv_protocol_t           proto;  /* Raw data or HVSI packets */
  74         struct hvsi_priv        hvsi;   /* HVSI specific data */
  75         spinlock_t              buf_lock;
  76         char                    buf[SIZE_VIO_GET_CHARS];
  77         int                     left;
  78         int                     offset;
  79 };
  80 static struct hvterm_priv *hvterm_privs[MAX_NR_HVC_CONSOLES];
  81 /* For early boot console */
  82 static struct hvterm_priv hvterm_priv0;
  83
  84 static int hvterm_raw_get_chars(uint32_t vtermno, char *buf, int count)
  85 {
  86         struct hvterm_priv *pv = hvterm_privs[vtermno];
  87         unsigned long i;
  88         unsigned long flags;
  89         int got;
  90
  91         if (WARN_ON(!pv))
  92                 return 0;
  93
  94         spin_lock_irqsave(&pv->buf_lock, flags);
  95
  96         if (pv->left == 0) {
  97                 pv->offset = 0;
  98                 pv->left = hvc_get_chars(pv->termno, pv->buf, count);
  99
 100                 /*
 101                  * Work around a HV bug where it gives us a null
 102                  * after every \r.  -- paulus
 103                  */
 104                 for (i = 1; i < pv->left; ++i) {
 105                         if (pv->buf[i] == 0 && pv->buf[i-1] == '\r') {
 106                                 --pv->left;
 107                                 if (i < pv->left) {
 108                                         memmove(&pv->buf[i], &pv->buf[i+1],
 109                                                 pv->left - i);
 110                                 }
 111                         }
 112                 }
 113         }
 114
 115         got = min(count, pv->left);
 116         memcpy(buf, &pv->buf[pv->offset], got);
 117         pv->offset += got;
 118         pv->left -= got;
 119
 120         spin_unlock_irqrestore(&pv->buf_lock, flags);
 121
 122         return got;
 123 }
 124
 125 static int hvterm_raw_put_chars(uint32_t vtermno, const char *buf, int count)
 126 {
 127         struct hvterm_priv *pv = hvterm_privs[vtermno];
 128
 129         if (WARN_ON(!pv))
 130                 return 0;
 131
 132         return hvc_put_chars(pv->termno, buf, count);
 133 }
 134
 135 static const struct hv_ops hvterm_raw_ops = {
 136         .get_chars = hvterm_raw_get_chars,
 137         .put_chars = hvterm_raw_put_chars,
 138         .notifier_add = notifier_add_irq,
 139         .notifier_del = notifier_del_irq,
 140         .notifier_hangup = notifier_hangup_irq,
 141 };
 142
 143 static int hvterm_hvsi_get_chars(uint32_t vtermno, char *buf, int count)
 144 {
 145         struct hvterm_priv *pv = hvterm_privs[vtermno];
 146
 147         if (WARN_ON(!pv))
 148                 return 0;
 149
 150         return hvsilib_get_chars(&pv->hvsi, buf, count);
 151 }
 152
 153 static int hvterm_hvsi_put_chars(uint32_t vtermno, const char *buf, int count)
 154 {
 155         struct hvterm_priv *pv = hvterm_privs[vtermno];
 156
 157         if (WARN_ON(!pv))
 158                 return 0;
 159
 160         return hvsilib_put_chars(&pv->hvsi, buf, count);
 161 }
 162
 163 static int hvterm_hvsi_open(struct hvc_struct *hp, int data)
 164 {
 165         struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
 166         int rc;
 167
 168         pr_devel("HVSI@%x: open !\n", pv->termno);
 169
 170         rc = notifier_add_irq(hp, data);
 171         if (rc)
 172                 return rc;
 173
 174         return hvsilib_open(&pv->hvsi, hp);
 175 }
 176
 177 static void hvterm_hvsi_close(struct hvc_struct *hp, int data)
 178 {
 179         struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
 180
 181         pr_devel("HVSI@%x: do close !\n", pv->termno);
 182
 183         hvsilib_close(&pv->hvsi, hp);
 184
 185         notifier_del_irq(hp, data);
 186 }
 187
 188 void hvterm_hvsi_hangup(struct hvc_struct *hp, int data)
 189 {
 190         struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
 191
 192         pr_devel("HVSI@%x: do hangup !\n", pv->termno);
 193
 194         hvsilib_close(&pv->hvsi, hp);
 195
 196         notifier_hangup_irq(hp, data);
 197 }
 198
 199 static int hvterm_hvsi_tiocmget(struct hvc_struct *hp)
 200 {
 201         struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
 202
 203         if (!pv)
 204                 return -EINVAL;
 205         return pv->hvsi.mctrl;
 206 }
 207
 208 static int hvterm_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
 209                                 unsigned int clear)
 210 {
 211         struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
 212
 213         pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
 214                  pv->termno, set, clear);
 215
 216         if (set & TIOCM_DTR)
 217                 hvsilib_write_mctrl(&pv->hvsi, 1);
 218         else if (clear & TIOCM_DTR)
 219                 hvsilib_write_mctrl(&pv->hvsi, 0);
 220
 221         return 0;
 222 }
 223
 224 static const struct hv_ops hvterm_hvsi_ops = {
 225         .get_chars = hvterm_hvsi_get_chars,
 226         .put_chars = hvterm_hvsi_put_chars,
 227         .notifier_add = hvterm_hvsi_open,
 228         .notifier_del = hvterm_hvsi_close,
 229         .notifier_hangup = hvterm_hvsi_hangup,
 230         .tiocmget = hvterm_hvsi_tiocmget,
 231         .tiocmset = hvterm_hvsi_tiocmset,
 232 };
 233
 234 static void udbg_hvc_putc(char c)
 235 {
 236         int count = -1;
 237
 238         if (!hvterm_privs[0])
 239                 return;
 240
 241         if (c == '\n')
 242                 udbg_hvc_putc('\r');
 243
 244         do {
 245                 switch(hvterm_privs[0]->proto) {
 246                 case HV_PROTOCOL_RAW:
 247                         count = hvterm_raw_put_chars(0, &c, 1);
 248                         break;
 249                 case HV_PROTOCOL_HVSI:
 250                         count = hvterm_hvsi_put_chars(0, &c, 1);
 251                         break;
 252                 }
 253         } while(count == 0);
 254 }
 255
 256 static int udbg_hvc_getc_poll(void)
 257 {
 258         int rc = 0;
 259         char c;
 260
 261         if (!hvterm_privs[0])
 262                 return -1;
 263
 264         switch(hvterm_privs[0]->proto) {
 265         case HV_PROTOCOL_RAW:
 266                 rc = hvterm_raw_get_chars(0, &c, 1);
 267                 break;
 268         case HV_PROTOCOL_HVSI:
 269                 rc = hvterm_hvsi_get_chars(0, &c, 1);
 270                 break;
 271         }
 272         if (!rc)
 273                 return -1;
 274         return c;
 275 }
 276
 277 static int udbg_hvc_getc(void)
 278 {
 279         int ch;
 280
 281         if (!hvterm_privs[0])
 282                 return -1;
 283
 284         for (;;) {
 285                 ch = udbg_hvc_getc_poll();
 286                 if (ch == -1) {
 287                         /* This shouldn't be needed...but... */
 288                         volatile unsigned long delay;
 289                         for (delay=0; delay < 2000000; delay++)
 290                                 ;
 291                 } else {
 292                         return ch;
 293                 }
 294         }
 295 }
 296
 297 static int hvc_vio_probe(struct vio_dev *vdev,
 298                                    const struct vio_device_id *id)
 299 {
 300         const struct hv_ops *ops;
 301         struct hvc_struct *hp;
 302         struct hvterm_priv *pv;
 303         hv_protocol_t proto;
 304         int i, termno = -1;
 305
 306         /* probed with invalid parameters. */
 307         if (!vdev || !id)
 308                 return -EPERM;
 309
 310         if (of_device_is_compatible(vdev->dev.of_node, "hvterm1")) {
 311                 proto = HV_PROTOCOL_RAW;
 312                 ops = &hvterm_raw_ops;
 313         } else if (of_device_is_compatible(vdev->dev.of_node, "hvterm-protocol")) {
 314                 proto = HV_PROTOCOL_HVSI;
 315                 ops = &hvterm_hvsi_ops;
 316         } else {
 317                 pr_err("hvc_vio: Unknown protocol for %s\n", vdev->dev.of_node->full_name);
 318                 return -ENXIO;
 319         }
 320
 321         pr_devel("hvc_vio_probe() device %s, using %s protocol\n",
 322                  vdev->dev.of_node->full_name,
 323                  proto == HV_PROTOCOL_RAW ? "raw" : "hvsi");
 324
 325         /* Is it our boot one ? */
 326         if (hvterm_privs[0] == &hvterm_priv0 &&
 327             vdev->unit_address == hvterm_priv0.termno) {
 328                 pv = hvterm_privs[0];
 329                 termno = 0;
 330                 pr_devel("->boot console, using termno 0\n");
 331         }
 332         /* nope, allocate a new one */
 333         else {
 334                 for (i = 0; i < MAX_NR_HVC_CONSOLES && termno < 0; i++)
 335                         if (!hvterm_privs[i])
 336                                 termno = i;
 337                 pr_devel("->non-boot console, using termno %d\n", termno);
 338                 if (termno < 0)
 339                         return -ENODEV;
 340                 pv = kzalloc(sizeof(struct hvterm_priv), GFP_KERNEL);
 341                 if (!pv)
 342                         return -ENOMEM;
 343                 pv->termno = vdev->unit_address;
 344                 pv->proto = proto;
 345                 spin_lock_init(&pv->buf_lock);
 346                 hvterm_privs[termno] = pv;
 347                 hvsilib_init(&pv->hvsi, hvc_get_chars, hvc_put_chars,
 348                              pv->termno, 0);
 349         }
 350
 351         hp = hvc_alloc(termno, vdev->irq, ops, MAX_VIO_PUT_CHARS);
 352         if (IS_ERR(hp))
 353                 return PTR_ERR(hp);
 354         dev_set_drvdata(&vdev->dev, hp);
 355
 356         /* register udbg if it's not there already for console 0 */
 357         if (hp->index == 0 && !udbg_putc) {
 358                 udbg_putc = udbg_hvc_putc;
 359                 udbg_getc = udbg_hvc_getc;
 360                 udbg_getc_poll = udbg_hvc_getc_poll;
 361         }
 362
 363         return 0;
 364 }
 365
 366 static int hvc_vio_remove(struct vio_dev *vdev)
 367 {
 368         struct hvc_struct *hp = dev_get_drvdata(&vdev->dev);
 369         int rc, termno;
 370
 371         termno = hp->vtermno;
 372         rc = hvc_remove(hp);
 373         if (rc == 0) {
 374                 if (hvterm_privs[termno] != &hvterm_priv0)
 375                         kfree(hvterm_privs[termno]);
 376                 hvterm_privs[termno] = NULL;
 377         }
 378         return rc;
 379 }
 380
 381 static struct vio_driver hvc_vio_driver = {
 382         .id_table       = hvc_driver_table,
 383         .probe          = hvc_vio_probe,
 384         .remove         = hvc_vio_remove,
 385         .name           = hvc_driver_name,
 386 };
 387
 388 static int __init hvc_vio_init(void)
 389 {
 390         int rc;
 391
 392         /* Register as a vio device to receive callbacks */
 393         rc = vio_register_driver(&hvc_vio_driver);
 394
 395         return rc;
 396 }
 397 module_init(hvc_vio_init); /* after drivers/char/hvc_console.c */
 398
 399 static void __exit hvc_vio_exit(void)
 400 {
 401         vio_unregister_driver(&hvc_vio_driver);
 402 }
 403 module_exit(hvc_vio_exit);
 404
 405 void __init hvc_vio_init_early(void)
 406 {
 407         const __be32 *termno;
 408         const char *name;
 409         const struct hv_ops *ops;
 410
 411         /* find the boot console from /chosen/stdout */
 412         if (!of_stdout)
 413                 return;
 414         name = of_get_property(of_stdout, "name", NULL);
 415         if (!name) {
 416                 printk(KERN_WARNING "stdout node missing 'name' property!\n");
 417                 return;
 418         }
 419
 420         /* Check if it's a virtual terminal */
 421         if (strncmp(name, "vty", 3) != 0)
 422                 return;
 423         termno = of_get_property(of_stdout, "reg", NULL);
 424         if (termno == NULL)
 425                 return;
 426         hvterm_priv0.termno = of_read_number(termno, 1);
 427         spin_lock_init(&hvterm_priv0.buf_lock);
 428         hvterm_privs[0] = &hvterm_priv0;
 429
 430         /* Check the protocol */
 431         if (of_device_is_compatible(of_stdout, "hvterm1")) {
 432                 hvterm_priv0.proto = HV_PROTOCOL_RAW;
 433                 ops = &hvterm_raw_ops;
 434         }
 435         else if (of_device_is_compatible(of_stdout, "hvterm-protocol")) {
 436                 hvterm_priv0.proto = HV_PROTOCOL_HVSI;
 437                 ops = &hvterm_hvsi_ops;
 438                 hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
 439                              hvterm_priv0.termno, 1);
 440                 /* HVSI, perform the handshake now */
 441                 hvsilib_establish(&hvterm_priv0.hvsi);
 442         } else
 443                 return;
 444         udbg_putc = udbg_hvc_putc;
 445         udbg_getc = udbg_hvc_getc;
 446         udbg_getc_poll = udbg_hvc_getc_poll;
 447 #ifdef HVC_OLD_HVSI
 448         /* When using the old HVSI driver don't register the HVC
 449          * backend for HVSI, only do udbg
 450          */
 451         if (hvterm_priv0.proto == HV_PROTOCOL_HVSI)
 452                 return;
 453 #endif
 454         /* Check whether the user has requested a different console. */
 455         if (!strstr(boot_command_line, "console="))
 456                 add_preferred_console("hvc", 0, NULL);
 457         hvc_instantiate(0, 0, ops);
 458 }
 459
 460 /* call this from early_init() for a working debug console on
 461  * vterm capable LPAR machines
 462  */
 463 #ifdef CONFIG_PPC_EARLY_DEBUG_LPAR
 464 void __init udbg_init_debug_lpar(void)
 465 {
 466         hvterm_privs[0] = &hvterm_priv0;
 467         hvterm_priv0.termno = 0;
 468         hvterm_priv0.proto = HV_PROTOCOL_RAW;
 469         spin_lock_init(&hvterm_priv0.buf_lock);
 470         udbg_putc = udbg_hvc_putc;
 471         udbg_getc = udbg_hvc_getc;
 472         udbg_getc_poll = udbg_hvc_getc_poll;
 473 }
 474 #endif /* CONFIG_PPC_EARLY_DEBUG_LPAR */
 475
 476 #ifdef CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI
 477 void __init udbg_init_debug_lpar_hvsi(void)
 478 {
 479         hvterm_privs[0] = &hvterm_priv0;
 480         hvterm_priv0.termno = CONFIG_PPC_EARLY_DEBUG_HVSI_VTERMNO;
 481         hvterm_priv0.proto = HV_PROTOCOL_HVSI;
 482         spin_lock_init(&hvterm_priv0.buf_lock);
 483         udbg_putc = udbg_hvc_putc;
 484         udbg_getc = udbg_hvc_getc;
 485         udbg_getc_poll = udbg_hvc_getc_poll;
 486         hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
 487                      hvterm_priv0.termno, 1);
 488         hvsilib_establish(&hvterm_priv0.hvsi);
 489 }
 490 #endif /* CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI */