arch/powerpc/kernel/legacy_serial.c

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