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 <linux/of_device.h>
   8 #include <asm/io.h>
   9 #include <asm/mmu.h>
  10 #include <asm/prom.h>
  11 #include <asm/serial.h>
  12 #include <asm/udbg.h>
  13 #include <asm/pci-bridge.h>
  14 #include <asm/ppc-pci.h>
  15
  16 #undef DEBUG
  17
  18 #ifdef DEBUG
  19 #define DBG(fmt...) do { printk(fmt); } while(0)
  20 #else
  21 #define DBG(fmt...) do { } while(0)
  22 #endif
  23
  24 #define MAX_LEGACY_SERIAL_PORTS 8
  25
  26 static struct plat_serial8250_port
  27 legacy_serial_ports[MAX_LEGACY_SERIAL_PORTS+1];
  28 static struct legacy_serial_info {
  29         struct device_node              *np;
  30         unsigned int                    speed;
  31         unsigned int                    clock;
  32         int                             irq_check_parent;
  33         phys_addr_t                     taddr;
  34 } legacy_serial_infos[MAX_LEGACY_SERIAL_PORTS];
  35
  36 static struct __initdata of_device_id parents[] = {
  37         {.type = "soc",},
  38         {.type = "tsi-bridge",},
  39         {.type = "opb", },
  40         {.compatible = "ibm,opb",},
  41         {.compatible = "simple-bus",},
  42         {.compatible = "wrs,epld-localbus",},
  43 };
  44
  45 static unsigned int legacy_serial_count;
  46 static int legacy_serial_console = -1;
  47
  48 static int __init add_legacy_port(struct device_node *np, int want_index,
  49                                   int iotype, phys_addr_t base,
  50                                   phys_addr_t taddr, unsigned long irq,
  51                                   upf_t flags, int irq_check_parent)
  52 {
  53         const u32 *clk, *spd;
  54         u32 clock = BASE_BAUD * 16;
  55         int index;
  56
  57         /* get clock freq. if present */
  58         clk = of_get_property(np, "clock-frequency", NULL);
  59         if (clk && *clk)
  60                 clock = *clk;
  61
  62         /* get default speed if present */
  63         spd = of_get_property(np, "current-speed", NULL);
  64
  65         /* If we have a location index, then try to use it */
  66         if (want_index >= 0 && want_index < MAX_LEGACY_SERIAL_PORTS)
  67                 index = want_index;
  68         else
  69                 index = legacy_serial_count;
  70
  71         /* if our index is still out of range, that mean that
  72          * array is full, we could scan for a free slot but that
  73          * make little sense to bother, just skip the port
  74          */
  75         if (index >= MAX_LEGACY_SERIAL_PORTS)
  76                 return -1;
  77         if (index >= legacy_serial_count)
  78                 legacy_serial_count = index + 1;
  79
  80         /* Check if there is a port who already claimed our slot */
  81         if (legacy_serial_infos[index].np != 0) {
  82                 /* if we still have some room, move it, else override */
  83                 if (legacy_serial_count < MAX_LEGACY_SERIAL_PORTS) {
  84                         printk(KERN_DEBUG "Moved legacy port %d -> %d\n",
  85                                index, legacy_serial_count);
  86                         legacy_serial_ports[legacy_serial_count] =
  87                                 legacy_serial_ports[index];
  88                         legacy_serial_infos[legacy_serial_count] =
  89                                 legacy_serial_infos[index];
  90                         legacy_serial_count++;
  91                 } else {
  92                         printk(KERN_DEBUG "Replacing legacy port %d\n", index);
  93                 }
  94         }
  95
  96         /* Now fill the entry */
  97         memset(&legacy_serial_ports[index], 0,
  98                sizeof(struct plat_serial8250_port));
  99         if (iotype == UPIO_PORT)
 100                 legacy_serial_ports[index].iobase = base;
 101         else
 102                 legacy_serial_ports[index].mapbase = base;
 103         legacy_serial_ports[index].iotype = iotype;
 104         legacy_serial_ports[index].uartclk = clock;
 105         legacy_serial_ports[index].irq = irq;
 106         legacy_serial_ports[index].flags = flags;
 107         legacy_serial_infos[index].taddr = taddr;
 108         legacy_serial_infos[index].np = of_node_get(np);
 109         legacy_serial_infos[index].clock = clock;
 110         legacy_serial_infos[index].speed = spd ? *spd : 0;
 111         legacy_serial_infos[index].irq_check_parent = irq_check_parent;
 112
 113         printk(KERN_DEBUG "Found legacy serial port %d for %s\n",
 114                index, np->full_name);
 115         printk(KERN_DEBUG "  %s=%llx, taddr=%llx, irq=%lx, clk=%d, speed=%d\n",
 116                (iotype == UPIO_PORT) ? "port" : "mem",
 117                (unsigned long long)base, (unsigned long long)taddr, irq,
 118                legacy_serial_ports[index].uartclk,
 119                legacy_serial_infos[index].speed);
 120
 121         return index;
 122 }
 123
 124 static int __init add_legacy_soc_port(struct device_node *np,
 125                                       struct device_node *soc_dev)
 126 {
 127         u64 addr;
 128         const u32 *addrp;
 129         upf_t flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST | UPF_SHARE_IRQ
 130                 | UPF_FIXED_PORT;
 131         struct device_node *tsi = of_get_parent(np);
 132
 133         /* We only support ports that have a clock frequency properly
 134          * encoded in the device-tree.
 135          */
 136         if (of_get_property(np, "clock-frequency", NULL) == NULL)
 137                 return -1;
 138
 139         /* if rtas uses this device, don't try to use it as well */
 140         if (of_get_property(np, "used-by-rtas", NULL) != NULL)
 141                 return -1;
 142
 143         /* Get the address */
 144         addrp = of_get_address(soc_dev, 0, NULL, NULL);
 145         if (addrp == NULL)
 146                 return -1;
 147
 148         addr = of_translate_address(soc_dev, addrp);
 149         if (addr == OF_BAD_ADDR)
 150                 return -1;
 151
 152         /* Add port, irq will be dealt with later. We passed a translated
 153          * IO port value. It will be fixed up later along with the irq
 154          */
 155         if (tsi && !strcmp(tsi->type, "tsi-bridge"))
 156                 return add_legacy_port(np, -1, UPIO_TSI, addr, addr, NO_IRQ, flags, 0);
 157         else
 158                 return add_legacy_port(np, -1, UPIO_MEM, addr, addr, NO_IRQ, flags, 0);
 159 }
 160
 161 static int __init add_legacy_isa_port(struct device_node *np,
 162                                       struct device_node *isa_brg)
 163 {
 164         const u32 *reg;
 165         const char *typep;
 166         int index = -1;
 167         u64 taddr;
 168
 169         DBG(" -> add_legacy_isa_port(%s)\n", np->full_name);
 170
 171         /* Get the ISA port number */
 172         reg = of_get_property(np, "reg", NULL);
 173         if (reg == NULL)
 174                 return -1;
 175
 176         /* Verify it's an IO port, we don't support anything else */
 177         if (!(reg[0] & 0x00000001))
 178                 return -1;
 179
 180         /* Now look for an "ibm,aix-loc" property that gives us ordering
 181          * if any...
 182          */
 183         typep = of_get_property(np, "ibm,aix-loc", NULL);
 184
 185         /* If we have a location index, then use it */
 186         if (typep && *typep == 'S')
 187                 index = simple_strtol(typep+1, NULL, 0) - 1;
 188
 189         /* Translate ISA address. If it fails, we still register the port
 190          * with no translated address so that it can be picked up as an IO
 191          * port later by the serial driver
 192          */
 193         taddr = of_translate_address(np, reg);
 194         if (taddr == OF_BAD_ADDR)
 195                 taddr = 0;
 196
 197         /* Add port, irq will be dealt with later */
 198         return add_legacy_port(np, index, UPIO_PORT, reg[1], taddr,
 199                                NO_IRQ, UPF_BOOT_AUTOCONF, 0);
 200
 201 }
 202
 203 #ifdef CONFIG_PCI
 204 static int __init add_legacy_pci_port(struct device_node *np,
 205                                       struct device_node *pci_dev)
 206 {
 207         u64 addr, base;
 208         const u32 *addrp;
 209         unsigned int flags;
 210         int iotype, index = -1, lindex = 0;
 211
 212         DBG(" -> add_legacy_pci_port(%s)\n", np->full_name);
 213
 214         /* We only support ports that have a clock frequency properly
 215          * encoded in the device-tree (that is have an fcode). Anything
 216          * else can't be used that early and will be normally probed by
 217          * the generic 8250_pci driver later on. The reason is that 8250
 218          * compatible UARTs on PCI need all sort of quirks (port offsets
 219          * etc...) that this code doesn't know about
 220          */
 221         if (of_get_property(np, "clock-frequency", NULL) == NULL)
 222                 return -1;
 223
 224         /* Get the PCI address. Assume BAR 0 */
 225         addrp = of_get_pci_address(pci_dev, 0, NULL, &flags);
 226         if (addrp == NULL)
 227                 return -1;
 228
 229         /* We only support BAR 0 for now */
 230         iotype = (flags & IORESOURCE_MEM) ? UPIO_MEM : UPIO_PORT;
 231         addr = of_translate_address(pci_dev, addrp);
 232         if (addr == OF_BAD_ADDR)
 233                 return -1;
 234
 235         /* Set the IO base to the same as the translated address for MMIO,
 236          * or to the domain local IO base for PIO (it will be fixed up later)
 237          */
 238         if (iotype == UPIO_MEM)
 239                 base = addr;
 240         else
 241                 base = addrp[2];
 242
 243         /* Try to guess an index... If we have subdevices of the pci dev,
 244          * we get to their "reg" property
 245          */
 246         if (np != pci_dev) {
 247                 const u32 *reg = of_get_property(np, "reg", NULL);
 248                 if (reg && (*reg < 4))
 249                         index = lindex = *reg;
 250         }
 251
 252         /* Local index means it's the Nth port in the PCI chip. Unfortunately
 253          * the offset to add here is device specific. We know about those
 254          * EXAR ports and we default to the most common case. If your UART
 255          * doesn't work for these settings, you'll have to add your own special
 256          * cases here
 257          */
 258         if (of_device_is_compatible(pci_dev, "pci13a8,152") ||
 259             of_device_is_compatible(pci_dev, "pci13a8,154") ||
 260             of_device_is_compatible(pci_dev, "pci13a8,158")) {
 261                 addr += 0x200 * lindex;
 262                 base += 0x200 * lindex;
 263         } else {
 264                 addr += 8 * lindex;
 265                 base += 8 * lindex;
 266         }
 267
 268         /* Add port, irq will be dealt with later. We passed a translated
 269          * IO port value. It will be fixed up later along with the irq
 270          */
 271         return add_legacy_port(np, index, iotype, base, addr, NO_IRQ,
 272                                UPF_BOOT_AUTOCONF, np != pci_dev);
 273 }
 274 #endif
 275
 276 static void __init setup_legacy_serial_console(int console)
 277 {
 278         struct legacy_serial_info *info =
 279                 &legacy_serial_infos[console];
 280         void __iomem *addr;
 281
 282         if (info->taddr == 0)
 283                 return;
 284         addr = ioremap(info->taddr, 0x1000);
 285         if (addr == NULL)
 286                 return;
 287         if (info->speed == 0)
 288                 info->speed = udbg_probe_uart_speed(addr, info->clock);
 289         DBG("default console speed = %d\n", info->speed);
 290         udbg_init_uart(addr, info->speed, info->clock);
 291 }
 292
 293 /*
 294  * This is called very early, as part of setup_system() or eventually
 295  * setup_arch(), basically before anything else in this file. This function
 296  * will try to build a list of all the available 8250-compatible serial ports
 297  * in the machine using the Open Firmware device-tree. It currently only deals
 298  * with ISA and PCI busses but could be extended. It allows a very early boot
 299  * console to be initialized, that list is also used later to provide 8250 with
 300  * the machine non-PCI ports and to properly pick the default console port
 301  */
 302 void __init find_legacy_serial_ports(void)
 303 {
 304         struct device_node *np, *stdout = NULL;
 305         const char *path;
 306         int index;
 307
 308         DBG(" -> find_legacy_serial_port()\n");
 309
 310         /* Now find out if one of these is out firmware console */
 311         path = of_get_property(of_chosen, "linux,stdout-path", NULL);
 312         if (path != NULL) {
 313                 stdout = of_find_node_by_path(path);
 314                 if (stdout)
 315                         DBG("stdout is %s\n", stdout->full_name);
 316         } else {
 317                 DBG(" no linux,stdout-path !\n");
 318         }
 319
 320         /* Iterate over all the 16550 ports, looking for known parents */
 321         for_each_compatible_node(np, "serial", "ns16550") {
 322                 struct device_node *parent = of_get_parent(np);
 323                 if (!parent)
 324                         continue;
 325                 if (of_match_node(parents, parent) != NULL) {
 326                         index = add_legacy_soc_port(np, np);
 327                         if (index >= 0 && np == stdout)
 328                                 legacy_serial_console = index;
 329                 }
 330                 of_node_put(parent);
 331         }
 332
 333         /* Next, fill our array with ISA ports */
 334         for_each_node_by_type(np, "serial") {
 335                 struct device_node *isa = of_get_parent(np);
 336                 if (isa && !strcmp(isa->name, "isa")) {
 337                         index = add_legacy_isa_port(np, isa);
 338                         if (index >= 0 && np == stdout)
 339                                 legacy_serial_console = index;
 340                 }
 341                 of_node_put(isa);
 342         }
 343
 344 #ifdef CONFIG_PCI
 345         /* Next, try to locate PCI ports */
 346         for (np = NULL; (np = of_find_all_nodes(np));) {
 347                 struct device_node *pci, *parent = of_get_parent(np);
 348                 if (parent && !strcmp(parent->name, "isa")) {
 349                         of_node_put(parent);
 350                         continue;
 351                 }
 352                 if (strcmp(np->name, "serial") && strcmp(np->type, "serial")) {
 353                         of_node_put(parent);
 354                         continue;
 355                 }
 356                 /* Check for known pciclass, and also check wether we have
 357                  * a device with child nodes for ports or not
 358                  */
 359                 if (of_device_is_compatible(np, "pciclass,0700") ||
 360                     of_device_is_compatible(np, "pciclass,070002"))
 361                         pci = np;
 362                 else if (of_device_is_compatible(parent, "pciclass,0700") ||
 363                          of_device_is_compatible(parent, "pciclass,070002"))
 364                         pci = parent;
 365                 else {
 366                         of_node_put(parent);
 367                         continue;
 368                 }
 369                 index = add_legacy_pci_port(np, pci);
 370                 if (index >= 0 && np == stdout)
 371                         legacy_serial_console = index;
 372                 of_node_put(parent);
 373         }
 374 #endif
 375
 376         DBG("legacy_serial_console = %d\n", legacy_serial_console);
 377         if (legacy_serial_console >= 0)
 378                 setup_legacy_serial_console(legacy_serial_console);
 379         DBG(" <- find_legacy_serial_port()\n");
 380 }
 381
 382 static struct platform_device serial_device = {
 383         .name   = "serial8250",
 384         .id     = PLAT8250_DEV_PLATFORM,
 385         .dev    = {
 386                 .platform_data = legacy_serial_ports,
 387         },
 388 };
 389
 390 static void __init fixup_port_irq(int index,
 391                                   struct device_node *np,
 392                                   struct plat_serial8250_port *port)
 393 {
 394         unsigned int virq;
 395
 396         DBG("fixup_port_irq(%d)\n", index);
 397
 398         virq = irq_of_parse_and_map(np, 0);
 399         if (virq == NO_IRQ && legacy_serial_infos[index].irq_check_parent) {
 400                 np = of_get_parent(np);
 401                 if (np == NULL)
 402                         return;
 403                 virq = irq_of_parse_and_map(np, 0);
 404                 of_node_put(np);
 405         }
 406         if (virq == NO_IRQ)
 407                 return;
 408
 409         port->irq = virq;
 410 }
 411
 412 static void __init fixup_port_pio(int index,
 413                                   struct device_node *np,
 414                                   struct plat_serial8250_port *port)
 415 {
 416 #ifdef CONFIG_PCI
 417         struct pci_controller *hose;
 418
 419         DBG("fixup_port_pio(%d)\n", index);
 420
 421         hose = pci_find_hose_for_OF_device(np);
 422         if (hose) {
 423                 unsigned long offset = (unsigned long)hose->io_base_virt -
 424 #ifdef CONFIG_PPC64
 425                         pci_io_base;
 426 #else
 427                         isa_io_base;
 428 #endif
 429                 DBG("port %d, IO %lx -> %lx\n",
 430                     index, port->iobase, port->iobase + offset);
 431                 port->iobase += offset;
 432         }
 433 #endif
 434 }
 435
 436 static void __init fixup_port_mmio(int index,
 437                                    struct device_node *np,
 438                                    struct plat_serial8250_port *port)
 439 {
 440         DBG("fixup_port_mmio(%d)\n", index);
 441
 442         port->membase = ioremap(port->mapbase, 0x100);
 443 }
 444
 445 /*
 446  * This is called as an arch initcall, hopefully before the PCI bus is
 447  * probed and/or the 8250 driver loaded since we need to register our
 448  * platform devices before 8250 PCI ones are detected as some of them
 449  * must properly "override" the platform ones.
 450  *
 451  * This function fixes up the interrupt value for platform ports as it
 452  * couldn't be done earlier before interrupt maps have been parsed. It
 453  * also "corrects" the IO address for PIO ports for the same reason,
 454  * since earlier, the PHBs virtual IO space wasn't assigned yet. It then
 455  * registers all those platform ports for use by the 8250 driver when it
 456  * finally loads.
 457  */
 458 static int __init serial_dev_init(void)
 459 {
 460         int i;
 461
 462         if (legacy_serial_count == 0)
 463                 return -ENODEV;
 464
 465         /*
 466          * Before we register the platfrom serial devices, we need
 467          * to fixup their interrupts and their IO ports.
 468          */
 469         DBG("Fixing serial ports interrupts and IO ports ...\n");
 470
 471         for (i = 0; i < legacy_serial_count; i++) {
 472                 struct plat_serial8250_port *port = &legacy_serial_ports[i];
 473                 struct device_node *np = legacy_serial_infos[i].np;
 474
 475                 if (port->irq == NO_IRQ)
 476                         fixup_port_irq(i, np, port);
 477                 if (port->iotype == UPIO_PORT)
 478                         fixup_port_pio(i, np, port);
 479                 if ((port->iotype == UPIO_MEM) || (port->iotype == UPIO_TSI))
 480                         fixup_port_mmio(i, np, port);
 481         }
 482
 483         DBG("Registering platform serial ports\n");
 484
 485         return platform_device_register(&serial_device);
 486 }
 487 device_initcall(serial_dev_init);
 488
 489
 490 /*
 491  * This is called very early, as part of console_init() (typically just after
 492  * time_init()). This function is respondible for trying to find a good
 493  * default console on serial ports. It tries to match the open firmware
 494  * default output with one of the available serial console drivers, either
 495  * one of the platform serial ports that have been probed earlier by
 496  * find_legacy_serial_ports() or some more platform specific ones.
 497  */
 498 static int __init check_legacy_serial_console(void)
 499 {
 500         struct device_node *prom_stdout = NULL;
 501         int speed = 0, offset = 0;
 502         const char *name;
 503         const u32 *spd;
 504
 505         DBG(" -> check_legacy_serial_console()\n");
 506
 507         /* The user has requested a console so this is already set up. */
 508         if (strstr(boot_command_line, "console=")) {
 509                 DBG(" console was specified !\n");
 510                 return -EBUSY;
 511         }
 512
 513         if (!of_chosen) {
 514                 DBG(" of_chosen is NULL !\n");
 515                 return -ENODEV;
 516         }
 517
 518         if (legacy_serial_console < 0) {
 519                 DBG(" legacy_serial_console not found !\n");
 520                 return -ENODEV;
 521         }
 522         /* We are getting a weird phandle from OF ... */
 523         /* ... So use the full path instead */
 524         name = of_get_property(of_chosen, "linux,stdout-path", NULL);
 525         if (name == NULL) {
 526                 DBG(" no linux,stdout-path !\n");
 527                 return -ENODEV;
 528         }
 529         prom_stdout = of_find_node_by_path(name);
 530         if (!prom_stdout) {
 531                 DBG(" can't find stdout package %s !\n", name);
 532                 return -ENODEV;
 533         }
 534         DBG("stdout is %s\n", prom_stdout->full_name);
 535
 536         name = of_get_property(prom_stdout, "name", NULL);
 537         if (!name) {
 538                 DBG(" stdout package has no name !\n");
 539                 goto not_found;
 540         }
 541         spd = of_get_property(prom_stdout, "current-speed", NULL);
 542         if (spd)
 543                 speed = *spd;
 544
 545         if (0)
 546                 ;
 547 #ifdef CONFIG_SERIAL_8250_CONSOLE
 548         else if (strcmp(name, "serial") == 0) {
 549                 int i;
 550                 /* Look for it in probed array */
 551                 for (i = 0; i < legacy_serial_count; i++) {
 552                         if (prom_stdout != legacy_serial_infos[i].np)
 553                                 continue;
 554                         offset = i;
 555                         speed = legacy_serial_infos[i].speed;
 556                         break;
 557                 }
 558                 if (i >= legacy_serial_count)
 559                         goto not_found;
 560         }
 561 #endif /* CONFIG_SERIAL_8250_CONSOLE */
 562 #ifdef CONFIG_SERIAL_PMACZILOG_CONSOLE
 563         else if (strcmp(name, "ch-a") == 0)
 564                 offset = 0;
 565         else if (strcmp(name, "ch-b") == 0)
 566                 offset = 1;
 567 #endif /* CONFIG_SERIAL_PMACZILOG_CONSOLE */
 568         else
 569                 goto not_found;
 570         of_node_put(prom_stdout);
 571
 572         DBG("Found serial console at ttyS%d\n", offset);
 573
 574         if (speed) {
 575                 static char __initdata opt[16];
 576                 sprintf(opt, "%d", speed);
 577                 return add_preferred_console("ttyS", offset, opt);
 578         } else
 579                 return add_preferred_console("ttyS", offset, NULL);
 580
 581  not_found:
 582         DBG("No preferred console found !\n");
 583         of_node_put(prom_stdout);
 584         return -ENODEV;
 585 }
 586 console_initcall(check_legacy_serial_console);
 587