drivers/tty/hvc/hvc_opal.c

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