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         .flush = opal_flush_chars,
  56         .notifier_add = notifier_add_irq,
  57         .notifier_del = notifier_del_irq,
  58         .notifier_hangup = notifier_hangup_irq,
  59 };
  60
  61 static 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
  71 static 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
  81 static 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
  95 static 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
 106 static 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
 117 static 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
 126 static 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
 142 static 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
 153 static 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
 235 static 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
 250 static 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
 259 static 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 }
 267 device_initcall(hvc_opal_init);
 268
 269 static 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
 294 static 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
 313 static 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
 323 static 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
 330 void __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);
 392 out:
 393         of_node_put(stdout_node);
 394 }
 395
 396 #ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_RAW
 397 void __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
 408 void __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 */