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_irq.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/export.h>
  19 #include <linux/interrupt.h>
  20
  21 #include <asm/hvconsole.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 ssize_t hvc_opal_hvsi_get_chars(uint32_t vtermno, u8 *buf, size_t 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 ssize_t hvc_opal_hvsi_put_chars(uint32_t vtermno, const u8 *buf,
  72                                        size_t count)
  73 {
  74         struct hvc_opal_priv *pv = hvc_opal_privs[vtermno];
  75
  76         if (WARN_ON(!pv))
  77                 return -ENODEV;
  78
  79         return hvsilib_put_chars(&pv->hvsi, buf, count);
  80 }
  81
  82 static int hvc_opal_hvsi_open(struct hvc_struct *hp, int data)
  83 {
  84         struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
  85         int rc;
  86
  87         pr_devel("HVSI@%x: do open !\n", hp->vtermno);
  88
  89         rc = notifier_add_irq(hp, data);
  90         if (rc)
  91                 return rc;
  92
  93         return hvsilib_open(&pv->hvsi, hp);
  94 }
  95
  96 static void hvc_opal_hvsi_close(struct hvc_struct *hp, int data)
  97 {
  98         struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
  99
 100         pr_devel("HVSI@%x: do close !\n", hp->vtermno);
 101
 102         hvsilib_close(&pv->hvsi, hp);
 103
 104         notifier_del_irq(hp, data);
 105 }
 106
 107 static void hvc_opal_hvsi_hangup(struct hvc_struct *hp, int data)
 108 {
 109         struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
 110
 111         pr_devel("HVSI@%x: do hangup !\n", hp->vtermno);
 112
 113         hvsilib_close(&pv->hvsi, hp);
 114
 115         notifier_hangup_irq(hp, data);
 116 }
 117
 118 static int hvc_opal_hvsi_tiocmget(struct hvc_struct *hp)
 119 {
 120         struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
 121
 122         if (!pv)
 123                 return -EINVAL;
 124         return pv->hvsi.mctrl;
 125 }
 126
 127 static int hvc_opal_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
 128                                 unsigned int clear)
 129 {
 130         struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
 131
 132         pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
 133                  hp->vtermno, set, clear);
 134
 135         if (set & TIOCM_DTR)
 136                 hvsilib_write_mctrl(&pv->hvsi, 1);
 137         else if (clear & TIOCM_DTR)
 138                 hvsilib_write_mctrl(&pv->hvsi, 0);
 139
 140         return 0;
 141 }
 142
 143 static const struct hv_ops hvc_opal_hvsi_ops = {
 144         .get_chars = hvc_opal_hvsi_get_chars,
 145         .put_chars = hvc_opal_hvsi_put_chars,
 146         .flush = opal_flush_chars,
 147         .notifier_add = hvc_opal_hvsi_open,
 148         .notifier_del = hvc_opal_hvsi_close,
 149         .notifier_hangup = hvc_opal_hvsi_hangup,
 150         .tiocmget = hvc_opal_hvsi_tiocmget,
 151         .tiocmset = hvc_opal_hvsi_tiocmset,
 152 };
 153
 154 static int hvc_opal_probe(struct platform_device *dev)
 155 {
 156         const struct hv_ops *ops;
 157         struct hvc_struct *hp;
 158         struct hvc_opal_priv *pv;
 159         hv_protocol_t proto;
 160         unsigned int termno, irq, boot = 0;
 161         const __be32 *reg;
 162
 163         if (of_device_is_compatible(dev->dev.of_node, "ibm,opal-console-raw")) {
 164                 proto = HV_PROTOCOL_RAW;
 165                 ops = &hvc_opal_raw_ops;
 166         } else if (of_device_is_compatible(dev->dev.of_node,
 167                                            "ibm,opal-console-hvsi")) {
 168                 proto = HV_PROTOCOL_HVSI;
 169                 ops = &hvc_opal_hvsi_ops;
 170         } else {
 171                 pr_err("hvc_opal: Unknown protocol for %pOF\n",
 172                        dev->dev.of_node);
 173                 return -ENXIO;
 174         }
 175
 176         reg = of_get_property(dev->dev.of_node, "reg", NULL);
 177         termno = reg ? be32_to_cpup(reg) : 0;
 178
 179         /* Is it our boot one ? */
 180         if (hvc_opal_privs[termno] == &hvc_opal_boot_priv) {
 181                 pv = hvc_opal_privs[termno];
 182                 boot = 1;
 183         } else if (hvc_opal_privs[termno] == NULL) {
 184                 pv = kzalloc(sizeof(struct hvc_opal_priv), GFP_KERNEL);
 185                 if (!pv)
 186                         return -ENOMEM;
 187                 pv->proto = proto;
 188                 hvc_opal_privs[termno] = pv;
 189                 if (proto == HV_PROTOCOL_HVSI) {
 190                         /*
 191                          * We want put_chars to be atomic to avoid mangling of
 192                          * hvsi packets.
 193                          */
 194                         hvsilib_init(&pv->hvsi,
 195                                      opal_get_chars, opal_put_chars_atomic,
 196                                      termno, 0);
 197                 }
 198
 199                 /* Instanciate now to establish a mapping index==vtermno */
 200                 hvc_instantiate(termno, termno, ops);
 201         } else {
 202                 pr_err("hvc_opal: Device %pOF has duplicate terminal number #%d\n",
 203                        dev->dev.of_node, termno);
 204                 return -ENXIO;
 205         }
 206
 207         pr_info("hvc%d: %s protocol on %pOF%s\n", termno,
 208                 proto == HV_PROTOCOL_RAW ? "raw" : "hvsi",
 209                 dev->dev.of_node,
 210                 boot ? " (boot console)" : "");
 211
 212         irq = irq_of_parse_and_map(dev->dev.of_node, 0);
 213         if (!irq) {
 214                 pr_info("hvc%d: No interrupts property, using OPAL event\n",
 215                                 termno);
 216                 irq = opal_event_request(ilog2(OPAL_EVENT_CONSOLE_INPUT));
 217         }
 218
 219         if (!irq) {
 220                 pr_err("hvc_opal: Unable to map interrupt for device %pOF\n",
 221                         dev->dev.of_node);
 222                 return irq;
 223         }
 224
 225         hp = hvc_alloc(termno, irq, ops, MAX_VIO_PUT_CHARS);
 226         if (IS_ERR(hp))
 227                 return PTR_ERR(hp);
 228
 229         /* hvc consoles on powernv may need to share a single irq */
 230         hp->flags = IRQF_SHARED;
 231         dev_set_drvdata(&dev->dev, hp);
 232
 233         return 0;
 234 }
 235
 236 static void hvc_opal_remove(struct platform_device *dev)
 237 {
 238         struct hvc_struct *hp = dev_get_drvdata(&dev->dev);
 239         int termno;
 240
 241         termno = hp->vtermno;
 242         hvc_remove(hp);
 243         if (hvc_opal_privs[termno] != &hvc_opal_boot_priv)
 244                 kfree(hvc_opal_privs[termno]);
 245         hvc_opal_privs[termno] = NULL;
 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                 } else {
 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 (of_node_name_eq(np, "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 */