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