linux/drivers/tty/hvc/hvc_opal.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * opal driver interface to hvc_console.c
   4 *
   5 * Copyright 2011 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
   6 */
   7
   8#undef DEBUG
   9
  10#include <linux/types.h>
  11#include <linux/init.h>
  12#include <linux/delay.h>
  13#include <linux/slab.h>
  14#include <linux/console.h>
  15#include <linux/of.h>
  16#include <linux/of_platform.h>
  17#include <linux/export.h>
  18#include <linux/interrupt.h>
  19
  20#include <asm/hvconsole.h>
  21#include <asm/prom.h>
  22#include <asm/firmware.h>
  23#include <asm/hvsi.h>
  24#include <asm/udbg.h>
  25#include <asm/opal.h>
  26
  27#include "hvc_console.h"
  28
  29static const char hvc_opal_name[] = "hvc_opal";
  30
  31static const struct of_device_id hvc_opal_match[] = {
  32        { .name = "serial", .compatible = "ibm,opal-console-raw" },
  33        { .name = "serial", .compatible = "ibm,opal-console-hvsi" },
  34        { },
  35};
  36
  37typedef enum hv_protocol {
  38        HV_PROTOCOL_RAW,
  39        HV_PROTOCOL_HVSI
  40} hv_protocol_t;
  41
  42struct hvc_opal_priv {
  43        hv_protocol_t           proto;  /* Raw data or HVSI packets */
  44        struct hvsi_priv        hvsi;   /* HVSI specific data */
  45};
  46static struct hvc_opal_priv *hvc_opal_privs[MAX_NR_HVC_CONSOLES];
  47
  48/* For early boot console */
  49static struct hvc_opal_priv hvc_opal_boot_priv;
  50static u32 hvc_opal_boot_termno;
  51
  52static const struct hv_ops hvc_opal_raw_ops = {
  53        .get_chars = opal_get_chars,
  54        .put_chars = opal_put_chars,
  55        .flush = opal_flush_chars,
  56        .notifier_add = notifier_add_irq,
  57        .notifier_del = notifier_del_irq,
  58        .notifier_hangup = notifier_hangup_irq,
  59};
  60
  61static int hvc_opal_hvsi_get_chars(uint32_t vtermno, char *buf, int count)
  62{
  63        struct hvc_opal_priv *pv = hvc_opal_privs[vtermno];
  64
  65        if (WARN_ON(!pv))
  66                return -ENODEV;
  67
  68        return hvsilib_get_chars(&pv->hvsi, buf, count);
  69}
  70
  71static int hvc_opal_hvsi_put_chars(uint32_t vtermno, const char *buf, int count)
  72{
  73        struct hvc_opal_priv *pv = hvc_opal_privs[vtermno];
  74
  75        if (WARN_ON(!pv))
  76                return -ENODEV;
  77
  78        return hvsilib_put_chars(&pv->hvsi, buf, count);
  79}
  80
  81static int hvc_opal_hvsi_open(struct hvc_struct *hp, int data)
  82{
  83        struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
  84        int rc;
  85
  86        pr_devel("HVSI@%x: do open !\n", hp->vtermno);
  87
  88        rc = notifier_add_irq(hp, data);
  89        if (rc)
  90                return rc;
  91
  92        return hvsilib_open(&pv->hvsi, hp);
  93}
  94
  95static void hvc_opal_hvsi_close(struct hvc_struct *hp, int data)
  96{
  97        struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
  98
  99        pr_devel("HVSI@%x: do close !\n", hp->vtermno);
 100
 101        hvsilib_close(&pv->hvsi, hp);
 102
 103        notifier_del_irq(hp, data);
 104}
 105
 106static void hvc_opal_hvsi_hangup(struct hvc_struct *hp, int data)
 107{
 108        struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
 109
 110        pr_devel("HVSI@%x: do hangup !\n", hp->vtermno);
 111
 112        hvsilib_close(&pv->hvsi, hp);
 113
 114        notifier_hangup_irq(hp, data);
 115}
 116
 117static int hvc_opal_hvsi_tiocmget(struct hvc_struct *hp)
 118{
 119        struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
 120
 121        if (!pv)
 122                return -EINVAL;
 123        return pv->hvsi.mctrl;
 124}
 125
 126static int hvc_opal_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
 127                                unsigned int clear)
 128{
 129        struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
 130
 131        pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
 132                 hp->vtermno, set, clear);
 133
 134        if (set & TIOCM_DTR)
 135                hvsilib_write_mctrl(&pv->hvsi, 1);
 136        else if (clear & TIOCM_DTR)
 137                hvsilib_write_mctrl(&pv->hvsi, 0);
 138
 139        return 0;
 140}
 141
 142static const struct hv_ops hvc_opal_hvsi_ops = {
 143        .get_chars = hvc_opal_hvsi_get_chars,
 144        .put_chars = hvc_opal_hvsi_put_chars,
 145        .flush = opal_flush_chars,
 146        .notifier_add = hvc_opal_hvsi_open,
 147        .notifier_del = hvc_opal_hvsi_close,
 148        .notifier_hangup = hvc_opal_hvsi_hangup,
 149        .tiocmget = hvc_opal_hvsi_tiocmget,
 150        .tiocmset = hvc_opal_hvsi_tiocmset,
 151};
 152
 153static int hvc_opal_probe(struct platform_device *dev)
 154{
 155        const struct hv_ops *ops;
 156        struct hvc_struct *hp;
 157        struct hvc_opal_priv *pv;
 158        hv_protocol_t proto;
 159        unsigned int termno, irq, boot = 0;
 160        const __be32 *reg;
 161
 162        if (of_device_is_compatible(dev->dev.of_node, "ibm,opal-console-raw")) {
 163                proto = HV_PROTOCOL_RAW;
 164                ops = &hvc_opal_raw_ops;
 165        } else if (of_device_is_compatible(dev->dev.of_node,
 166                                           "ibm,opal-console-hvsi")) {
 167                proto = HV_PROTOCOL_HVSI;
 168                ops = &hvc_opal_hvsi_ops;
 169        } else {
 170                pr_err("hvc_opal: Unknown protocol for %pOF\n",
 171                       dev->dev.of_node);
 172                return -ENXIO;
 173        }
 174
 175        reg = of_get_property(dev->dev.of_node, "reg", NULL);
 176        termno = reg ? be32_to_cpup(reg) : 0;
 177
 178        /* Is it our boot one ? */
 179        if (hvc_opal_privs[termno] == &hvc_opal_boot_priv) {
 180                pv = hvc_opal_privs[termno];
 181                boot = 1;
 182        } else if (hvc_opal_privs[termno] == NULL) {
 183                pv = kzalloc(sizeof(struct hvc_opal_priv), GFP_KERNEL);
 184                if (!pv)
 185                        return -ENOMEM;
 186                pv->proto = proto;
 187                hvc_opal_privs[termno] = pv;
 188                if (proto == HV_PROTOCOL_HVSI) {
 189                        /*
 190                         * We want put_chars to be atomic to avoid mangling of
 191                         * hvsi packets.
 192                         */
 193                        hvsilib_init(&pv->hvsi,
 194                                     opal_get_chars, opal_put_chars_atomic,
 195                                     termno, 0);
 196                }
 197
 198                /* Instanciate now to establish a mapping index==vtermno */
 199                hvc_instantiate(termno, termno, ops);
 200        } else {
 201                pr_err("hvc_opal: Device %pOF has duplicate terminal number #%d\n",
 202                       dev->dev.of_node, termno);
 203                return -ENXIO;
 204        }
 205
 206        pr_info("hvc%d: %s protocol on %pOF%s\n", termno,
 207                proto == HV_PROTOCOL_RAW ? "raw" : "hvsi",
 208                dev->dev.of_node,
 209                boot ? " (boot console)" : "");
 210
 211        irq = irq_of_parse_and_map(dev->dev.of_node, 0);
 212        if (!irq) {
 213                pr_info("hvc%d: No interrupts property, using OPAL event\n",
 214                                termno);
 215                irq = opal_event_request(ilog2(OPAL_EVENT_CONSOLE_INPUT));
 216        }
 217
 218        if (!irq) {
 219                pr_err("hvc_opal: Unable to map interrupt for device %pOF\n",
 220                        dev->dev.of_node);
 221                return irq;
 222        }
 223
 224        hp = hvc_alloc(termno, irq, ops, MAX_VIO_PUT_CHARS);
 225        if (IS_ERR(hp))
 226                return PTR_ERR(hp);
 227
 228        /* hvc consoles on powernv may need to share a single irq */
 229        hp->flags = IRQF_SHARED;
 230        dev_set_drvdata(&dev->dev, hp);
 231
 232        return 0;
 233}
 234
 235static int hvc_opal_remove(struct platform_device *dev)
 236{
 237        struct hvc_struct *hp = dev_get_drvdata(&dev->dev);
 238        int rc, termno;
 239
 240        termno = hp->vtermno;
 241        rc = hvc_remove(hp);
 242        if (rc == 0) {
 243                if (hvc_opal_privs[termno] != &hvc_opal_boot_priv)
 244                        kfree(hvc_opal_privs[termno]);
 245                hvc_opal_privs[termno] = NULL;
 246        }
 247        return rc;
 248}
 249
 250static struct platform_driver hvc_opal_driver = {
 251        .probe          = hvc_opal_probe,
 252        .remove         = hvc_opal_remove,
 253        .driver         = {
 254                .name   = hvc_opal_name,
 255                .of_match_table = hvc_opal_match,
 256        }
 257};
 258
 259static int __init hvc_opal_init(void)
 260{
 261        if (!firmware_has_feature(FW_FEATURE_OPAL))
 262                return -ENODEV;
 263
 264        /* Register as a vio device to receive callbacks */
 265        return platform_driver_register(&hvc_opal_driver);
 266}
 267device_initcall(hvc_opal_init);
 268
 269static void udbg_opal_putc(char c)
 270{
 271        unsigned int termno = hvc_opal_boot_termno;
 272        int count = -1;
 273
 274        if (c == '\n')
 275                udbg_opal_putc('\r');
 276
 277        do {
 278                switch(hvc_opal_boot_priv.proto) {
 279                case HV_PROTOCOL_RAW:
 280                        count = opal_put_chars(termno, &c, 1);
 281                        break;
 282                case HV_PROTOCOL_HVSI:
 283                        count = hvc_opal_hvsi_put_chars(termno, &c, 1);
 284                        break;
 285                }
 286
 287                /* This is needed for the cosole to flush
 288                 * when there aren't any interrupts.
 289                 */
 290                opal_flush_console(termno);
 291        } while(count == 0 || count == -EAGAIN);
 292}
 293
 294static int udbg_opal_getc_poll(void)
 295{
 296        unsigned int termno = hvc_opal_boot_termno;
 297        int rc = 0;
 298        char c;
 299
 300        switch(hvc_opal_boot_priv.proto) {
 301        case HV_PROTOCOL_RAW:
 302                rc = opal_get_chars(termno, &c, 1);
 303                break;
 304        case HV_PROTOCOL_HVSI:
 305                rc = hvc_opal_hvsi_get_chars(termno, &c, 1);
 306                break;
 307        }
 308        if (!rc)
 309                return -1;
 310        return c;
 311}
 312
 313static int udbg_opal_getc(void)
 314{
 315        int ch;
 316        for (;;) {
 317                ch = udbg_opal_getc_poll();
 318                if (ch != -1)
 319                        return ch;
 320        }
 321}
 322
 323static void udbg_init_opal_common(void)
 324{
 325        udbg_putc = udbg_opal_putc;
 326        udbg_getc = udbg_opal_getc;
 327        udbg_getc_poll = udbg_opal_getc_poll;
 328}
 329
 330void __init hvc_opal_init_early(void)
 331{
 332        struct device_node *stdout_node = of_node_get(of_stdout);
 333        const __be32 *termno;
 334        const struct hv_ops *ops;
 335        u32 index;
 336
 337        /* If the console wasn't in /chosen, try /ibm,opal */
 338        if (!stdout_node) {
 339                struct device_node *opal, *np;
 340
 341                /* Current OPAL takeover doesn't provide the stdout
 342                 * path, so we hard wire it
 343                 */
 344                opal = of_find_node_by_path("/ibm,opal/consoles");
 345                if (opal)
 346                        pr_devel("hvc_opal: Found consoles in new location\n");
 347                if (!opal) {
 348                        opal = of_find_node_by_path("/ibm,opal");
 349                        if (opal)
 350                                pr_devel("hvc_opal: "
 351                                         "Found consoles in old location\n");
 352                }
 353                if (!opal)
 354                        return;
 355                for_each_child_of_node(opal, np) {
 356                        if (of_node_name_eq(np, "serial")) {
 357                                stdout_node = np;
 358                                break;
 359                        }
 360                }
 361                of_node_put(opal);
 362        }
 363        if (!stdout_node)
 364                return;
 365        termno = of_get_property(stdout_node, "reg", NULL);
 366        index = termno ? be32_to_cpup(termno) : 0;
 367        if (index >= MAX_NR_HVC_CONSOLES)
 368                return;
 369        hvc_opal_privs[index] = &hvc_opal_boot_priv;
 370
 371        /* Check the protocol */
 372        if (of_device_is_compatible(stdout_node, "ibm,opal-console-raw")) {
 373                hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
 374                ops = &hvc_opal_raw_ops;
 375                pr_devel("hvc_opal: Found RAW console\n");
 376        }
 377        else if (of_device_is_compatible(stdout_node,"ibm,opal-console-hvsi")) {
 378                hvc_opal_boot_priv.proto = HV_PROTOCOL_HVSI;
 379                ops = &hvc_opal_hvsi_ops;
 380                hvsilib_init(&hvc_opal_boot_priv.hvsi,
 381                             opal_get_chars, opal_put_chars_atomic,
 382                             index, 1);
 383                /* HVSI, perform the handshake now */
 384                hvsilib_establish(&hvc_opal_boot_priv.hvsi);
 385                pr_devel("hvc_opal: Found HVSI console\n");
 386        } else
 387                goto out;
 388        hvc_opal_boot_termno = index;
 389        udbg_init_opal_common();
 390        add_preferred_console("hvc", index, NULL);
 391        hvc_instantiate(index, index, ops);
 392out:
 393        of_node_put(stdout_node);
 394}
 395
 396#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_RAW
 397void __init udbg_init_debug_opal_raw(void)
 398{
 399        u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
 400        hvc_opal_privs[index] = &hvc_opal_boot_priv;
 401        hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
 402        hvc_opal_boot_termno = index;
 403        udbg_init_opal_common();
 404}
 405#endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_RAW */
 406
 407#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI
 408void __init udbg_init_debug_opal_hvsi(void)
 409{
 410        u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
 411        hvc_opal_privs[index] = &hvc_opal_boot_priv;
 412        hvc_opal_boot_termno = index;
 413        udbg_init_opal_common();
 414        hvsilib_init(&hvc_opal_boot_priv.hvsi,
 415                     opal_get_chars, opal_put_chars_atomic,
 416                     index, 1);
 417        hvsilib_establish(&hvc_opal_boot_priv.hvsi);
 418}
 419#endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI */
 420