drivers/tty/hvc/hvc_opal.c

   1 /*
   2  * opal driver interface to hvc_console.c
   3  *
   4  * Copyright 2011 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19  *
  20  */
  21
  22 #undef DEBUG
  23
  24 #include <linux/types.h>
  25 #include <linux/init.h>
  26 #include <linux/delay.h>
  27 #include <linux/slab.h>
  28 #include <linux/console.h>
  29 #include <linux/of.h>
  30 #include <linux/of_platform.h>
  31 #include <linux/export.h>
  32
  33 #include <asm/hvconsole.h>
  34 #include <asm/prom.h>
  35 #include <asm/firmware.h>
  36 #include <asm/hvsi.h>
  37 #include <asm/udbg.h>
  38 #include <asm/opal.h>
  39
  40 #include "hvc_console.h"
  41
  42 static const char hvc_opal_name[] = "hvc_opal";
  43
  44 static struct of_device_id hvc_opal_match[] = {
  45         { .name = "serial", .compatible = "ibm,opal-console-raw" },
  46         { .name = "serial", .compatible = "ibm,opal-console-hvsi" },
  47         { },
  48 };
  49
  50 typedef enum hv_protocol {
  51         HV_PROTOCOL_RAW,
  52         HV_PROTOCOL_HVSI
  53 } hv_protocol_t;
  54
  55 struct hvc_opal_priv {
  56         hv_protocol_t           proto;  /* Raw data or HVSI packets */
  57         struct hvsi_priv        hvsi;   /* HVSI specific data */
  58 };
  59 static struct hvc_opal_priv *hvc_opal_privs[MAX_NR_HVC_CONSOLES];
  60
  61 /* For early boot console */
  62 static struct hvc_opal_priv hvc_opal_boot_priv;
  63 static u32 hvc_opal_boot_termno;
  64 static bool hvc_opal_event_registered;
  65
  66 static const struct hv_ops hvc_opal_raw_ops = {
  67         .get_chars = opal_get_chars,
  68         .put_chars = opal_put_chars,
  69         .notifier_add = notifier_add_irq,
  70         .notifier_del = notifier_del_irq,
  71         .notifier_hangup = notifier_hangup_irq,
  72 };
  73
  74 static int hvc_opal_hvsi_get_chars(uint32_t vtermno, char *buf, int count)
  75 {
  76         struct hvc_opal_priv *pv = hvc_opal_privs[vtermno];
  77
  78         if (WARN_ON(!pv))
  79                 return -ENODEV;
  80
  81         return hvsilib_get_chars(&pv->hvsi, buf, count);
  82 }
  83
  84 static int hvc_opal_hvsi_put_chars(uint32_t vtermno, const char *buf, int count)
  85 {
  86         struct hvc_opal_priv *pv = hvc_opal_privs[vtermno];
  87
  88         if (WARN_ON(!pv))
  89                 return -ENODEV;
  90
  91         return hvsilib_put_chars(&pv->hvsi, buf, count);
  92 }
  93
  94 static int hvc_opal_hvsi_open(struct hvc_struct *hp, int data)
  95 {
  96         struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
  97         int rc;
  98
  99         pr_devel("HVSI@%x: do open !\n", hp->vtermno);
 100
 101         rc = notifier_add_irq(hp, data);
 102         if (rc)
 103                 return rc;
 104
 105         return hvsilib_open(&pv->hvsi, hp);
 106 }
 107
 108 static void hvc_opal_hvsi_close(struct hvc_struct *hp, int data)
 109 {
 110         struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
 111
 112         pr_devel("HVSI@%x: do close !\n", hp->vtermno);
 113
 114         hvsilib_close(&pv->hvsi, hp);
 115
 116         notifier_del_irq(hp, data);
 117 }
 118
 119 void hvc_opal_hvsi_hangup(struct hvc_struct *hp, int data)
 120 {
 121         struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
 122
 123         pr_devel("HVSI@%x: do hangup !\n", hp->vtermno);
 124
 125         hvsilib_close(&pv->hvsi, hp);
 126
 127         notifier_hangup_irq(hp, data);
 128 }
 129
 130 static int hvc_opal_hvsi_tiocmget(struct hvc_struct *hp)
 131 {
 132         struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
 133
 134         if (!pv)
 135                 return -EINVAL;
 136         return pv->hvsi.mctrl;
 137 }
 138
 139 static int hvc_opal_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
 140                                 unsigned int clear)
 141 {
 142         struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
 143
 144         pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
 145                  hp->vtermno, set, clear);
 146
 147         if (set & TIOCM_DTR)
 148                 hvsilib_write_mctrl(&pv->hvsi, 1);
 149         else if (clear & TIOCM_DTR)
 150                 hvsilib_write_mctrl(&pv->hvsi, 0);
 151
 152         return 0;
 153 }
 154
 155 static const struct hv_ops hvc_opal_hvsi_ops = {
 156         .get_chars = hvc_opal_hvsi_get_chars,
 157         .put_chars = hvc_opal_hvsi_put_chars,
 158         .notifier_add = hvc_opal_hvsi_open,
 159         .notifier_del = hvc_opal_hvsi_close,
 160         .notifier_hangup = hvc_opal_hvsi_hangup,
 161         .tiocmget = hvc_opal_hvsi_tiocmget,
 162         .tiocmset = hvc_opal_hvsi_tiocmset,
 163 };
 164
 165 static int hvc_opal_console_event(struct notifier_block *nb,
 166                                   unsigned long events, void *change)
 167 {
 168         if (events & OPAL_EVENT_CONSOLE_INPUT)
 169                 hvc_kick();
 170         return 0;
 171 }
 172
 173 static struct notifier_block hvc_opal_console_nb = {
 174         .notifier_call  = hvc_opal_console_event,
 175 };
 176
 177 static int hvc_opal_probe(struct platform_device *dev)
 178 {
 179         const struct hv_ops *ops;
 180         struct hvc_struct *hp;
 181         struct hvc_opal_priv *pv;
 182         hv_protocol_t proto;
 183         unsigned int termno, boot = 0;
 184         const __be32 *reg;
 185
 186
 187         if (of_device_is_compatible(dev->dev.of_node, "ibm,opal-console-raw")) {
 188                 proto = HV_PROTOCOL_RAW;
 189                 ops = &hvc_opal_raw_ops;
 190         } else if (of_device_is_compatible(dev->dev.of_node,
 191                                            "ibm,opal-console-hvsi")) {
 192                 proto = HV_PROTOCOL_HVSI;
 193                 ops = &hvc_opal_hvsi_ops;
 194         } else {
 195                 pr_err("hvc_opal: Unknown protocol for %s\n",
 196                        dev->dev.of_node->full_name);
 197                 return -ENXIO;
 198         }
 199
 200         reg = of_get_property(dev->dev.of_node, "reg", NULL);
 201         termno = reg ? be32_to_cpup(reg) : 0;
 202
 203         /* Is it our boot one ? */
 204         if (hvc_opal_privs[termno] == &hvc_opal_boot_priv) {
 205                 pv = hvc_opal_privs[termno];
 206                 boot = 1;
 207         } else if (hvc_opal_privs[termno] == NULL) {
 208                 pv = kzalloc(sizeof(struct hvc_opal_priv), GFP_KERNEL);
 209                 if (!pv)
 210                         return -ENOMEM;
 211                 pv->proto = proto;
 212                 hvc_opal_privs[termno] = pv;
 213                 if (proto == HV_PROTOCOL_HVSI)
 214                         hvsilib_init(&pv->hvsi, opal_get_chars, opal_put_chars,
 215                                      termno, 0);
 216
 217                 /* Instanciate now to establish a mapping index==vtermno */
 218                 hvc_instantiate(termno, termno, ops);
 219         } else {
 220                 pr_err("hvc_opal: Device %s has duplicate terminal number #%d\n",
 221                        dev->dev.of_node->full_name, termno);
 222                 return -ENXIO;
 223         }
 224
 225         pr_info("hvc%d: %s protocol on %s%s\n", termno,
 226                 proto == HV_PROTOCOL_RAW ? "raw" : "hvsi",
 227                 dev->dev.of_node->full_name,
 228                 boot ? " (boot console)" : "");
 229
 230         /* We don't do IRQ ... */
 231         hp = hvc_alloc(termno, 0, ops, MAX_VIO_PUT_CHARS);
 232         if (IS_ERR(hp))
 233                 return PTR_ERR(hp);
 234         dev_set_drvdata(&dev->dev, hp);
 235
 236         /* ...  but we use OPAL event to kick the console */
 237         if (!hvc_opal_event_registered) {
 238                 opal_notifier_register(&hvc_opal_console_nb);
 239                 hvc_opal_event_registered = true;
 240         }
 241
 242         return 0;
 243 }
 244
 245 static int hvc_opal_remove(struct platform_device *dev)
 246 {
 247         struct hvc_struct *hp = dev_get_drvdata(&dev->dev);
 248         int rc, termno;
 249
 250         termno = hp->vtermno;
 251         rc = hvc_remove(hp);
 252         if (rc == 0) {
 253                 if (hvc_opal_privs[termno] != &hvc_opal_boot_priv)
 254                         kfree(hvc_opal_privs[termno]);
 255                 hvc_opal_privs[termno] = NULL;
 256         }
 257         return rc;
 258 }
 259
 260 static struct platform_driver hvc_opal_driver = {
 261         .probe          = hvc_opal_probe,
 262         .remove         = hvc_opal_remove,
 263         .driver         = {
 264                 .name   = hvc_opal_name,
 265                 .owner  = THIS_MODULE,
 266                 .of_match_table = hvc_opal_match,
 267         }
 268 };
 269
 270 static int __init hvc_opal_init(void)
 271 {
 272         if (!firmware_has_feature(FW_FEATURE_OPAL))
 273                 return -ENODEV;
 274
 275         /* Register as a vio device to receive callbacks */
 276         return platform_driver_register(&hvc_opal_driver);
 277 }
 278 device_initcall(hvc_opal_init);
 279
 280 static void udbg_opal_putc(char c)
 281 {
 282         unsigned int termno = hvc_opal_boot_termno;
 283         int count = -1;
 284
 285         if (c == '\n')
 286                 udbg_opal_putc('\r');
 287
 288         do {
 289                 switch(hvc_opal_boot_priv.proto) {
 290                 case HV_PROTOCOL_RAW:
 291                         count = opal_put_chars(termno, &c, 1);
 292                         break;
 293                 case HV_PROTOCOL_HVSI:
 294                         count = hvc_opal_hvsi_put_chars(termno, &c, 1);
 295                         break;
 296                 }
 297         } while(count == 0 || count == -EAGAIN);
 298 }
 299
 300 static int udbg_opal_getc_poll(void)
 301 {
 302         unsigned int termno = hvc_opal_boot_termno;
 303         int rc = 0;
 304         char c;
 305
 306         switch(hvc_opal_boot_priv.proto) {
 307         case HV_PROTOCOL_RAW:
 308                 rc = opal_get_chars(termno, &c, 1);
 309                 break;
 310         case HV_PROTOCOL_HVSI:
 311                 rc = hvc_opal_hvsi_get_chars(termno, &c, 1);
 312                 break;
 313         }
 314         if (!rc)
 315                 return -1;
 316         return c;
 317 }
 318
 319 static int udbg_opal_getc(void)
 320 {
 321         int ch;
 322         for (;;) {
 323                 ch = udbg_opal_getc_poll();
 324                 if (ch == -1) {
 325                         /* This shouldn't be needed...but... */
 326                         volatile unsigned long delay;
 327                         for (delay=0; delay < 2000000; delay++)
 328                                 ;
 329                 } else {
 330                         return ch;
 331                 }
 332         }
 333 }
 334
 335 static void udbg_init_opal_common(void)
 336 {
 337         udbg_putc = udbg_opal_putc;
 338         udbg_getc = udbg_opal_getc;
 339         udbg_getc_poll = udbg_opal_getc_poll;
 340         tb_ticks_per_usec = 0x200; /* Make udelay not suck */
 341 }
 342
 343 void __init hvc_opal_init_early(void)
 344 {
 345         struct device_node *stdout_node = NULL;
 346         const __be32 *termno;
 347         const char *name = NULL;
 348         const struct hv_ops *ops;
 349         u32 index;
 350
 351         /* find the boot console from /chosen/stdout */
 352         if (of_chosen)
 353                 name = of_get_property(of_chosen, "linux,stdout-path", NULL);
 354         if (name) {
 355                 stdout_node = of_find_node_by_path(name);
 356                 if (!stdout_node) {
 357                         pr_err("hvc_opal: Failed to locate default console!\n");
 358                         return;
 359                 }
 360         } else {
 361                 struct device_node *opal, *np;
 362
 363                 /* Current OPAL takeover doesn't provide the stdout
 364                  * path, so we hard wire it
 365                  */
 366                 opal = of_find_node_by_path("/ibm,opal/consoles");
 367                 if (opal)
 368                         pr_devel("hvc_opal: Found consoles in new location\n");
 369                 if (!opal) {
 370                         opal = of_find_node_by_path("/ibm,opal");
 371                         if (opal)
 372                                 pr_devel("hvc_opal: "
 373                                          "Found consoles in old location\n");
 374                 }
 375                 if (!opal)
 376                         return;
 377                 for_each_child_of_node(opal, np) {
 378                         if (!strcmp(np->name, "serial")) {
 379                                 stdout_node = np;
 380                                 break;
 381                         }
 382                 }
 383                 of_node_put(opal);
 384         }
 385         if (!stdout_node)
 386                 return;
 387         termno = of_get_property(stdout_node, "reg", NULL);
 388         index = termno ? be32_to_cpup(termno) : 0;
 389         if (index >= MAX_NR_HVC_CONSOLES)
 390                 return;
 391         hvc_opal_privs[index] = &hvc_opal_boot_priv;
 392
 393         /* Check the protocol */
 394         if (of_device_is_compatible(stdout_node, "ibm,opal-console-raw")) {
 395                 hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
 396                 ops = &hvc_opal_raw_ops;
 397                 pr_devel("hvc_opal: Found RAW console\n");
 398         }
 399         else if (of_device_is_compatible(stdout_node,"ibm,opal-console-hvsi")) {
 400                 hvc_opal_boot_priv.proto = HV_PROTOCOL_HVSI;
 401                 ops = &hvc_opal_hvsi_ops;
 402                 hvsilib_init(&hvc_opal_boot_priv.hvsi, opal_get_chars,
 403                              opal_put_chars, index, 1);
 404                 /* HVSI, perform the handshake now */
 405                 hvsilib_establish(&hvc_opal_boot_priv.hvsi);
 406                 pr_devel("hvc_opal: Found HVSI console\n");
 407         } else
 408                 goto out;
 409         hvc_opal_boot_termno = index;
 410         udbg_init_opal_common();
 411         add_preferred_console("hvc", index, NULL);
 412         hvc_instantiate(index, index, ops);
 413 out:
 414         of_node_put(stdout_node);
 415 }
 416
 417 #ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_RAW
 418 void __init udbg_init_debug_opal_raw(void)
 419 {
 420         u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
 421         hvc_opal_privs[index] = &hvc_opal_boot_priv;
 422         hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
 423         hvc_opal_boot_termno = index;
 424         udbg_init_opal_common();
 425 }
 426 #endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_RAW */
 427
 428 #ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI
 429 void __init udbg_init_debug_opal_hvsi(void)
 430 {
 431         u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
 432         hvc_opal_privs[index] = &hvc_opal_boot_priv;
 433         hvc_opal_boot_termno = index;
 434         udbg_init_opal_common();
 435         hvsilib_init(&hvc_opal_boot_priv.hvsi, opal_get_chars, opal_put_chars,
 436                      index, 1);
 437         hvsilib_establish(&hvc_opal_boot_priv.hvsi);
 438 }
 439 #endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI */