arch/powerpc/kernel/legacy_serial.c

   1 #include <linux/kernel.h>
   2 #include <linux/serial.h>
   3 #include <linux/serial_8250.h>
   4 #include <linux/serial_core.h>
   5 #include <linux/console.h>
   6 #include <linux/pci.h>
   7 #include <asm/io.h>
   8 #include <asm/mmu.h>
   9 #include <asm/prom.h>
  10 #include <asm/serial.h>
  11 #include <asm/udbg.h>
  12 #include <asm/pci-bridge.h>
  13 #include <asm/ppc-pci.h>
  14
  15 #undef DEBUG
  16
  17 #ifdef DEBUG
  18 #define DBG(fmt...) do { printk(fmt); } while(0)
  19 #else
  20 #define DBG(fmt...) do { } while(0)
  21 #endif
  22
  23 #define MAX_LEGACY_SERIAL_PORTS 8
  24
  25 static struct plat_serial8250_port
  26 legacy_serial_ports[MAX_LEGACY_SERIAL_PORTS+1];
  27 static struct legacy_serial_info {
  28         struct device_node              *np;
  29         unsigned int                    speed;
  30         unsigned int                    clock;
  31         int                             irq_check_parent;
  32         phys_addr_t                     taddr;
  33 } legacy_serial_infos[MAX_LEGACY_SERIAL_PORTS];
  34 static unsigned int legacy_serial_count;
  35 static int legacy_serial_console = -1;
  36
  37 static int __init add_legacy_port(struct device_node *np, int want_index,
  38                                   int iotype, phys_addr_t base,
  39                                   phys_addr_t taddr, unsigned long irq,
  40                                   upf_t flags, int irq_check_parent)
  41 {
  42         u32 *clk, *spd, clock = BASE_BAUD * 16;
  43         int index;
  44
  45         /* get clock freq. if present */
  46         clk = (u32 *)get_property(np, "clock-frequency", NULL);
  47         if (clk && *clk)
  48                 clock = *clk;
  49
  50         /* get default speed if present */
  51         spd = (u32 *)get_property(np, "current-speed", NULL);
  52
  53         /* If we have a location index, then try to use it */
  54         if (want_index >= 0 && want_index < MAX_LEGACY_SERIAL_PORTS)
  55                 index = want_index;
  56         else
  57                 index = legacy_serial_count;
  58
  59         /* if our index is still out of range, that mean that
  60          * array is full, we could scan for a free slot but that
  61          * make little sense to bother, just skip the port
  62          */
  63         if (index >= MAX_LEGACY_SERIAL_PORTS)
  64                 return -1;
  65         if (index >= legacy_serial_count)
  66                 legacy_serial_count = index + 1;
  67
  68         /* Check if there is a port who already claimed our slot */
  69         if (legacy_serial_infos[index].np != 0) {
  70                 /* if we still have some room, move it, else override */
  71                 if (legacy_serial_count < MAX_LEGACY_SERIAL_PORTS) {
  72                         printk(KERN_DEBUG "Moved legacy port %d -> %d\n",
  73                                index, legacy_serial_count);
  74                         legacy_serial_ports[legacy_serial_count] =
  75                                 legacy_serial_ports[index];
  76                         legacy_serial_infos[legacy_serial_count] =
  77                                 legacy_serial_infos[index];
  78                         legacy_serial_count++;
  79                 } else {
  80                         printk(KERN_DEBUG "Replacing legacy port %d\n", index);
  81                 }
  82         }
  83
  84         /* Now fill the entry */
  85         memset(&legacy_serial_ports[index], 0,
  86                sizeof(struct plat_serial8250_port));
  87         if (iotype == UPIO_PORT)
  88                 legacy_serial_ports[index].iobase = base;
  89         else
  90                 legacy_serial_ports[index].mapbase = base;
  91         legacy_serial_ports[index].iotype = iotype;
  92         legacy_serial_ports[index].uartclk = clock;
  93         legacy_serial_ports[index].irq = irq;
  94         legacy_serial_ports[index].flags = flags;
  95         legacy_serial_infos[index].taddr = taddr;
  96         legacy_serial_infos[index].np = of_node_get(np);
  97         legacy_serial_infos[index].clock = clock;
  98         legacy_serial_infos[index].speed = spd ? *spd : 0;
  99         legacy_serial_infos[index].irq_check_parent = irq_check_parent;
 100
 101         printk(KERN_DEBUG "Found legacy serial port %d for %s\n",
 102                index, np->full_name);
 103         printk(KERN_DEBUG "  %s=%llx, taddr=%llx, irq=%lx, clk=%d, speed=%d\n",
 104                (iotype == UPIO_PORT) ? "port" : "mem",
 105                (unsigned long long)base, (unsigned long long)taddr, irq,
 106                legacy_serial_ports[index].uartclk,
 107                legacy_serial_infos[index].speed);
 108
 109         return index;
 110 }
 111
 112 static int __init add_legacy_soc_port(struct device_node *np,
 113                                       struct device_node *soc_dev)
 114 {
 115         u64 addr;
 116         u32 *addrp;
 117         upf_t flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST | UPF_SHARE_IRQ;
 118         struct device_node *tsi = of_get_parent(np);
 119
 120         /* We only support ports that have a clock frequency properly
 121          * encoded in the device-tree.
 122          */
 123         if (get_property(np, "clock-frequency", NULL) == NULL)
 124                 return -1;
 125
 126         /* Get the address */
 127         addrp = of_get_address(soc_dev, 0, NULL, NULL);
 128         if (addrp == NULL)
 129                 return -1;
 130
 131         addr = of_translate_address(soc_dev, addrp);
 132         if (addr == OF_BAD_ADDR)
 133                 return -1;
 134
 135         /* Add port, irq will be dealt with later. We passed a translated
 136          * IO port value. It will be fixed up later along with the irq
 137          */
 138         if (tsi && !strcmp(tsi->type, "tsi-bridge"))
 139                 return add_legacy_port(np, -1, UPIO_TSI, addr, addr, NO_IRQ, flags, 0);
 140         else
 141                 return add_legacy_port(np, -1, UPIO_MEM, addr, addr, NO_IRQ, flags, 0);
 142 }
 143
 144 static int __init add_legacy_isa_port(struct device_node *np,
 145                                       struct device_node *isa_brg)
 146 {
 147         u32 *reg;
 148         char *typep;
 149         int index = -1;
 150         u64 taddr;
 151
 152         DBG(" -> add_legacy_isa_port(%s)\n", np->full_name);
 153
 154         /* Get the ISA port number */
 155         reg = (u32 *)get_property(np, "reg", NULL);
 156         if (reg == NULL)
 157                 return -1;
 158
 159         /* Verify it's an IO port, we don't support anything else */
 160         if (!(reg[0] & 0x00000001))
 161                 return -1;
 162
 163         /* Now look for an "ibm,aix-loc" property that gives us ordering
 164          * if any...
 165          */
 166         typep = (char *)get_property(np, "ibm,aix-loc", NULL);
 167
 168         /* If we have a location index, then use it */
 169         if (typep && *typep == 'S')
 170                 index = simple_strtol(typep+1, NULL, 0) - 1;
 171
 172         /* Translate ISA address. If it fails, we still register the port
 173          * with no translated address so that it can be picked up as an IO
 174          * port later by the serial driver
 175          */
 176         taddr = of_translate_address(np, reg);
 177         if (taddr == OF_BAD_ADDR)
 178                 taddr = 0;
 179
 180         /* Add port, irq will be dealt with later */
 181         return add_legacy_port(np, index, UPIO_PORT, reg[1], taddr,
 182                                NO_IRQ, UPF_BOOT_AUTOCONF, 0);
 183
 184 }
 185
 186 #ifdef CONFIG_PCI
 187 static int __init add_legacy_pci_port(struct device_node *np,
 188                                       struct device_node *pci_dev)
 189 {
 190         u64 addr, base;
 191         u32 *addrp;
 192         unsigned int flags;
 193         int iotype, index = -1, lindex = 0;
 194
 195         DBG(" -> add_legacy_pci_port(%s)\n", np->full_name);
 196
 197         /* We only support ports that have a clock frequency properly
 198          * encoded in the device-tree (that is have an fcode). Anything
 199          * else can't be used that early and will be normally probed by
 200          * the generic 8250_pci driver later on. The reason is that 8250
 201          * compatible UARTs on PCI need all sort of quirks (port offsets
 202          * etc...) that this code doesn't know about
 203          */
 204         if (get_property(np, "clock-frequency", NULL) == NULL)
 205                 return -1;
 206
 207         /* Get the PCI address. Assume BAR 0 */
 208         addrp = of_get_pci_address(pci_dev, 0, NULL, &flags);
 209         if (addrp == NULL)
 210                 return -1;
 211
 212         /* We only support BAR 0 for now */
 213         iotype = (flags & IORESOURCE_MEM) ? UPIO_MEM : UPIO_PORT;
 214         addr = of_translate_address(pci_dev, addrp);
 215         if (addr == OF_BAD_ADDR)
 216                 return -1;
 217
 218         /* Set the IO base to the same as the translated address for MMIO,
 219          * or to the domain local IO base for PIO (it will be fixed up later)
 220          */
 221         if (iotype == UPIO_MEM)
 222                 base = addr;
 223         else
 224                 base = addrp[2];
 225
 226         /* Try to guess an index... If we have subdevices of the pci dev,
 227          * we get to their "reg" property
 228          */
 229         if (np != pci_dev) {
 230                 u32 *reg = (u32 *)get_property(np, "reg", NULL);
 231                 if (reg && (*reg < 4))
 232                         index = lindex = *reg;
 233         }
 234
 235         /* Local index means it's the Nth port in the PCI chip. Unfortunately
 236          * the offset to add here is device specific. We know about those
 237          * EXAR ports and we default to the most common case. If your UART
 238          * doesn't work for these settings, you'll have to add your own special
 239          * cases here
 240          */
 241         if (device_is_compatible(pci_dev, "pci13a8,152") ||
 242             device_is_compatible(pci_dev, "pci13a8,154") ||
 243             device_is_compatible(pci_dev, "pci13a8,158")) {
 244                 addr += 0x200 * lindex;
 245                 base += 0x200 * lindex;
 246         } else {
 247                 addr += 8 * lindex;
 248                 base += 8 * lindex;
 249         }
 250
 251         /* Add port, irq will be dealt with later. We passed a translated
 252          * IO port value. It will be fixed up later along with the irq
 253          */
 254         return add_legacy_port(np, index, iotype, base, addr, NO_IRQ,
 255                                UPF_BOOT_AUTOCONF, np != pci_dev);
 256 }
 257 #endif
 258
 259 static void __init setup_legacy_serial_console(int console)
 260 {
 261         struct legacy_serial_info *info =
 262                 &legacy_serial_infos[console];
 263         void __iomem *addr;
 264
 265         if (info->taddr == 0)
 266                 return;
 267         addr = ioremap(info->taddr, 0x1000);
 268         if (addr == NULL)
 269                 return;
 270         if (info->speed == 0)
 271                 info->speed = udbg_probe_uart_speed(addr, info->clock);
 272         DBG("default console speed = %d\n", info->speed);
 273         udbg_init_uart(addr, info->speed, info->clock);
 274 }
 275
 276 /*
 277  * This is called very early, as part of setup_system() or eventually
 278  * setup_arch(), basically before anything else in this file. This function
 279  * will try to build a list of all the available 8250-compatible serial ports
 280  * in the machine using the Open Firmware device-tree. It currently only deals
 281  * with ISA and PCI busses but could be extended. It allows a very early boot
 282  * console to be initialized, that list is also used later to provide 8250 with
 283  * the machine non-PCI ports and to properly pick the default console port
 284  */
 285 void __init find_legacy_serial_ports(void)
 286 {
 287         struct device_node *np, *stdout = NULL;
 288         char *path;
 289         int index;
 290
 291         DBG(" -> find_legacy_serial_port()\n");
 292
 293         /* Now find out if one of these is out firmware console */
 294         path = (char *)get_property(of_chosen, "linux,stdout-path", NULL);
 295         if (path != NULL) {
 296                 stdout = of_find_node_by_path(path);
 297                 if (stdout)
 298                         DBG("stdout is %s\n", stdout->full_name);
 299         } else {
 300                 DBG(" no linux,stdout-path !\n");
 301         }
 302
 303         /* First fill our array with SOC ports */
 304         for (np = NULL; (np = of_find_compatible_node(np, "serial", "ns16550")) != NULL;) {
 305                 struct device_node *soc = of_get_parent(np);
 306                 if (soc && !strcmp(soc->type, "soc")) {
 307                         index = add_legacy_soc_port(np, np);
 308                         if (index >= 0 && np == stdout)
 309                                 legacy_serial_console = index;
 310                 }
 311                 of_node_put(soc);
 312         }
 313
 314         /* First fill our array with ISA ports */
 315         for (np = NULL; (np = of_find_node_by_type(np, "serial"));) {
 316                 struct device_node *isa = of_get_parent(np);
 317                 if (isa && !strcmp(isa->name, "isa")) {
 318                         index = add_legacy_isa_port(np, isa);
 319                         if (index >= 0 && np == stdout)
 320                                 legacy_serial_console = index;
 321                 }
 322                 of_node_put(isa);
 323         }
 324
 325         /* First fill our array with tsi-bridge ports */
 326         for (np = NULL; (np = of_find_compatible_node(np, "serial", "ns16550")) != NULL;) {
 327                 struct device_node *tsi = of_get_parent(np);
 328                 if (tsi && !strcmp(tsi->type, "tsi-bridge")) {
 329                         index = add_legacy_soc_port(np, np);
 330                         if (index >= 0 && np == stdout)
 331                                 legacy_serial_console = index;
 332                 }
 333                 of_node_put(tsi);
 334         }
 335
 336 #ifdef CONFIG_PCI
 337         /* Next, try to locate PCI ports */
 338         for (np = NULL; (np = of_find_all_nodes(np));) {
 339                 struct device_node *pci, *parent = of_get_parent(np);
 340                 if (parent && !strcmp(parent->name, "isa")) {
 341                         of_node_put(parent);
 342                         continue;
 343                 }
 344                 if (strcmp(np->name, "serial") && strcmp(np->type, "serial")) {
 345                         of_node_put(parent);
 346                         continue;
 347                 }
 348                 /* Check for known pciclass, and also check wether we have
 349                  * a device with child nodes for ports or not
 350                  */
 351                 if (device_is_compatible(np, "pciclass,0700") ||
 352                     device_is_compatible(np, "pciclass,070002"))
 353                         pci = np;
 354                 else if (device_is_compatible(parent, "pciclass,0700") ||
 355                          device_is_compatible(parent, "pciclass,070002"))
 356                         pci = parent;
 357                 else {
 358                         of_node_put(parent);
 359                         continue;
 360                 }
 361                 index = add_legacy_pci_port(np, pci);
 362                 if (index >= 0 && np == stdout)
 363                         legacy_serial_console = index;
 364                 of_node_put(parent);
 365         }
 366 #endif
 367
 368         DBG("legacy_serial_console = %d\n", legacy_serial_console);
 369         if (legacy_serial_console >= 0)
 370                 setup_legacy_serial_console(legacy_serial_console);
 371         DBG(" <- find_legacy_serial_port()\n");
 372 }
 373
 374 static struct platform_device serial_device = {
 375         .name   = "serial8250",
 376         .id     = PLAT8250_DEV_PLATFORM,
 377         .dev    = {
 378                 .platform_data = legacy_serial_ports,
 379         },
 380 };
 381
 382 static void __init fixup_port_irq(int index,
 383                                   struct device_node *np,
 384                                   struct plat_serial8250_port *port)
 385 {
 386         unsigned int virq;
 387
 388         DBG("fixup_port_irq(%d)\n", index);
 389
 390         virq = irq_of_parse_and_map(np, 0);
 391         if (virq == NO_IRQ && legacy_serial_infos[index].irq_check_parent) {
 392                 np = of_get_parent(np);
 393                 if (np == NULL)
 394                         return;
 395                 virq = irq_of_parse_and_map(np, 0);
 396                 of_node_put(np);
 397         }
 398         if (virq == NO_IRQ)
 399                 return;
 400
 401         port->irq = virq;
 402 }
 403
 404 static void __init fixup_port_pio(int index,
 405                                   struct device_node *np,
 406                                   struct plat_serial8250_port *port)
 407 {
 408 #ifdef CONFIG_PCI
 409         struct pci_controller *hose;
 410
 411         DBG("fixup_port_pio(%d)\n", index);
 412
 413         hose = pci_find_hose_for_OF_device(np);
 414         if (hose) {
 415                 unsigned long offset = (unsigned long)hose->io_base_virt -
 416 #ifdef CONFIG_PPC64
 417                         pci_io_base;
 418 #else
 419                         isa_io_base;
 420 #endif
 421                 DBG("port %d, IO %lx -> %lx\n",
 422                     index, port->iobase, port->iobase + offset);
 423                 port->iobase += offset;
 424         }
 425 #endif
 426 }
 427
 428 static void __init fixup_port_mmio(int index,
 429                                    struct device_node *np,
 430                                    struct plat_serial8250_port *port)
 431 {
 432         DBG("fixup_port_mmio(%d)\n", index);
 433
 434         port->membase = ioremap(port->mapbase, 0x100);
 435 }
 436
 437 /*
 438  * This is called as an arch initcall, hopefully before the PCI bus is
 439  * probed and/or the 8250 driver loaded since we need to register our
 440  * platform devices before 8250 PCI ones are detected as some of them
 441  * must properly "override" the platform ones.
 442  *
 443  * This function fixes up the interrupt value for platform ports as it
 444  * couldn't be done earlier before interrupt maps have been parsed. It
 445  * also "corrects" the IO address for PIO ports for the same reason,
 446  * since earlier, the PHBs virtual IO space wasn't assigned yet. It then
 447  * registers all those platform ports for use by the 8250 driver when it
 448  * finally loads.
 449  */
 450 static int __init serial_dev_init(void)
 451 {
 452         int i;
 453
 454         if (legacy_serial_count == 0)
 455                 return -ENODEV;
 456
 457         /*
 458          * Before we register the platfrom serial devices, we need
 459          * to fixup their interrutps and their IO ports.
 460          */
 461         DBG("Fixing serial ports interrupts and IO ports ...\n");
 462
 463         for (i = 0; i < legacy_serial_count; i++) {
 464                 struct plat_serial8250_port *port = &legacy_serial_ports[i];
 465                 struct device_node *np = legacy_serial_infos[i].np;
 466
 467                 if (port->irq == NO_IRQ)
 468                         fixup_port_irq(i, np, port);
 469                 if (port->iotype == UPIO_PORT)
 470                         fixup_port_pio(i, np, port);
 471                 if ((port->iotype == UPIO_MEM) || (port->iotype == UPIO_TSI))
 472                         fixup_port_mmio(i, np, port);
 473         }
 474
 475         DBG("Registering platform serial ports\n");
 476
 477         return platform_device_register(&serial_device);
 478 }
 479 arch_initcall(serial_dev_init);
 480
 481
 482 /*
 483  * This is called very early, as part of console_init() (typically just after
 484  * time_init()). This function is respondible for trying to find a good
 485  * default console on serial ports. It tries to match the open firmware
 486  * default output with one of the available serial console drivers, either
 487  * one of the platform serial ports that have been probed earlier by
 488  * find_legacy_serial_ports() or some more platform specific ones.
 489  */
 490 static int __init check_legacy_serial_console(void)
 491 {
 492         struct device_node *prom_stdout = NULL;
 493         int speed = 0, offset = 0;
 494         char *name;
 495         u32 *spd;
 496
 497         DBG(" -> check_legacy_serial_console()\n");
 498
 499         /* The user has requested a console so this is already set up. */
 500         if (strstr(saved_command_line, "console=")) {
 501                 DBG(" console was specified !\n");
 502                 return -EBUSY;
 503         }
 504
 505         if (!of_chosen) {
 506                 DBG(" of_chosen is NULL !\n");
 507                 return -ENODEV;
 508         }
 509
 510         if (legacy_serial_console < 0) {
 511                 DBG(" legacy_serial_console not found !\n");
 512                 return -ENODEV;
 513         }
 514         /* We are getting a weird phandle from OF ... */
 515         /* ... So use the full path instead */
 516         name = (char *)get_property(of_chosen, "linux,stdout-path", NULL);
 517         if (name == NULL) {
 518                 DBG(" no linux,stdout-path !\n");
 519                 return -ENODEV;
 520         }
 521         prom_stdout = of_find_node_by_path(name);
 522         if (!prom_stdout) {
 523                 DBG(" can't find stdout package %s !\n", name);
 524                 return -ENODEV;
 525         }
 526         DBG("stdout is %s\n", prom_stdout->full_name);
 527
 528         name = (char *)get_property(prom_stdout, "name", NULL);
 529         if (!name) {
 530                 DBG(" stdout package has no name !\n");
 531                 goto not_found;
 532         }
 533         spd = (u32 *)get_property(prom_stdout, "current-speed", NULL);
 534         if (spd)
 535                 speed = *spd;
 536
 537         if (0)
 538                 ;
 539 #ifdef CONFIG_SERIAL_8250_CONSOLE
 540         else if (strcmp(name, "serial") == 0) {
 541                 int i;
 542                 /* Look for it in probed array */
 543                 for (i = 0; i < legacy_serial_count; i++) {
 544                         if (prom_stdout != legacy_serial_infos[i].np)
 545                                 continue;
 546                         offset = i;
 547                         speed = legacy_serial_infos[i].speed;
 548                         break;
 549                 }
 550                 if (i >= legacy_serial_count)
 551                         goto not_found;
 552         }
 553 #endif /* CONFIG_SERIAL_8250_CONSOLE */
 554 #ifdef CONFIG_SERIAL_PMACZILOG_CONSOLE
 555         else if (strcmp(name, "ch-a") == 0)
 556                 offset = 0;
 557         else if (strcmp(name, "ch-b") == 0)
 558                 offset = 1;
 559 #endif /* CONFIG_SERIAL_PMACZILOG_CONSOLE */
 560         else
 561                 goto not_found;
 562         of_node_put(prom_stdout);
 563
 564         DBG("Found serial console at ttyS%d\n", offset);
 565
 566         if (speed) {
 567                 static char __initdata opt[16];
 568                 sprintf(opt, "%d", speed);
 569                 return add_preferred_console("ttyS", offset, opt);
 570         } else
 571                 return add_preferred_console("ttyS", offset, NULL);
 572
 573  not_found:
 574         DBG("No preferred console found !\n");
 575         of_node_put(prom_stdout);
 576         return -ENODEV;
 577 }
 578 console_initcall(check_legacy_serial_console);
 579