linux/drivers/tty/hvc/hvc_opal.c
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   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
  42static const char hvc_opal_name[] = "hvc_opal";
  43
  44static 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
  50typedef enum hv_protocol {
  51        HV_PROTOCOL_RAW,
  52        HV_PROTOCOL_HVSI
  53} hv_protocol_t;
  54
  55struct hvc_opal_priv {
  56        hv_protocol_t           proto;  /* Raw data or HVSI packets */
  57        struct hvsi_priv        hvsi;   /* HVSI specific data */
  58};
  59static struct hvc_opal_priv *hvc_opal_privs[MAX_NR_HVC_CONSOLES];
  60
  61/* For early boot console */
  62static struct hvc_opal_priv hvc_opal_boot_priv;
  63static u32 hvc_opal_boot_termno;
  64static bool hvc_opal_event_registered;
  65
  66static 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
  74static 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
  84static 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
  94static 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
 108static 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
 119void 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
 130static 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
 139static 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
 155static 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
 165static 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
 173static struct notifier_block hvc_opal_console_nb = {
 174        .notifier_call  = hvc_opal_console_event,
 175};
 176
 177static 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
 245static 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
 260static 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
 270static 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}
 278device_initcall(hvc_opal_init);
 279
 280static 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
 300static 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
 319static 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
 335static 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
 343void __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);
 413out:
 414        of_node_put(stdout_node);
 415}
 416
 417#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_RAW
 418void __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
 429void __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 */
 440
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