linux/arch/powerpc/kernel/legacy_serial.c
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   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_address.h>
   8#include <linux/of_device.h>
   9#include <linux/serial_reg.h>
  10#include <asm/io.h>
  11#include <asm/mmu.h>
  12#include <asm/prom.h>
  13#include <asm/serial.h>
  14#include <asm/udbg.h>
  15#include <asm/pci-bridge.h>
  16#include <asm/ppc-pci.h>
  17
  18#undef DEBUG
  19
  20#ifdef DEBUG
  21#define DBG(fmt...) do { printk(fmt); } while(0)
  22#else
  23#define DBG(fmt...) do { } while(0)
  24#endif
  25
  26#define MAX_LEGACY_SERIAL_PORTS 8
  27
  28static struct plat_serial8250_port
  29legacy_serial_ports[MAX_LEGACY_SERIAL_PORTS+1];
  30static struct legacy_serial_info {
  31        struct device_node              *np;
  32        unsigned int                    speed;
  33        unsigned int                    clock;
  34        int                             irq_check_parent;
  35        phys_addr_t                     taddr;
  36} legacy_serial_infos[MAX_LEGACY_SERIAL_PORTS];
  37
  38static struct __initdata of_device_id legacy_serial_parents[] = {
  39        {.type = "soc",},
  40        {.type = "tsi-bridge",},
  41        {.type = "opb", },
  42        {.compatible = "ibm,opb",},
  43        {.compatible = "simple-bus",},
  44        {.compatible = "wrs,epld-localbus",},
  45        {},
  46};
  47
  48static unsigned int legacy_serial_count;
  49static int legacy_serial_console = -1;
  50
  51static unsigned int tsi_serial_in(struct uart_port *p, int offset)
  52{
  53        unsigned int tmp;
  54        offset = offset << p->regshift;
  55        if (offset == UART_IIR) {
  56                tmp = readl(p->membase + (UART_IIR & ~3));
  57                return (tmp >> 16) & 0xff; /* UART_IIR % 4 == 2 */
  58        } else
  59                return readb(p->membase + offset);
  60}
  61
  62static void tsi_serial_out(struct uart_port *p, int offset, int value)
  63{
  64        offset = offset << p->regshift;
  65        if (!((offset == UART_IER) && (value & UART_IER_UUE)))
  66                writeb(value, p->membase + offset);
  67}
  68
  69static int __init add_legacy_port(struct device_node *np, int want_index,
  70                                  int iotype, phys_addr_t base,
  71                                  phys_addr_t taddr, unsigned long irq,
  72                                  upf_t flags, int irq_check_parent)
  73{
  74        const __be32 *clk, *spd;
  75        u32 clock = BASE_BAUD * 16;
  76        int index;
  77
  78        /* get clock freq. if present */
  79        clk = of_get_property(np, "clock-frequency", NULL);
  80        if (clk && *clk)
  81                clock = be32_to_cpup(clk);
  82
  83        /* get default speed if present */
  84        spd = of_get_property(np, "current-speed", NULL);
  85
  86        /* If we have a location index, then try to use it */
  87        if (want_index >= 0 && want_index < MAX_LEGACY_SERIAL_PORTS)
  88                index = want_index;
  89        else
  90                index = legacy_serial_count;
  91
  92        /* if our index is still out of range, that mean that
  93         * array is full, we could scan for a free slot but that
  94         * make little sense to bother, just skip the port
  95         */
  96        if (index >= MAX_LEGACY_SERIAL_PORTS)
  97                return -1;
  98        if (index >= legacy_serial_count)
  99                legacy_serial_count = index + 1;
 100
 101        /* Check if there is a port who already claimed our slot */
 102        if (legacy_serial_infos[index].np != 0) {
 103                /* if we still have some room, move it, else override */
 104                if (legacy_serial_count < MAX_LEGACY_SERIAL_PORTS) {
 105                        printk(KERN_DEBUG "Moved legacy port %d -> %d\n",
 106                               index, legacy_serial_count);
 107                        legacy_serial_ports[legacy_serial_count] =
 108                                legacy_serial_ports[index];
 109                        legacy_serial_infos[legacy_serial_count] =
 110                                legacy_serial_infos[index];
 111                        legacy_serial_count++;
 112                } else {
 113                        printk(KERN_DEBUG "Replacing legacy port %d\n", index);
 114                }
 115        }
 116
 117        /* Now fill the entry */
 118        memset(&legacy_serial_ports[index], 0,
 119               sizeof(struct plat_serial8250_port));
 120        if (iotype == UPIO_PORT)
 121                legacy_serial_ports[index].iobase = base;
 122        else
 123                legacy_serial_ports[index].mapbase = base;
 124
 125        legacy_serial_ports[index].iotype = iotype;
 126        legacy_serial_ports[index].uartclk = clock;
 127        legacy_serial_ports[index].irq = irq;
 128        legacy_serial_ports[index].flags = flags;
 129        legacy_serial_infos[index].taddr = taddr;
 130        legacy_serial_infos[index].np = of_node_get(np);
 131        legacy_serial_infos[index].clock = clock;
 132        legacy_serial_infos[index].speed = spd ? be32_to_cpup(spd) : 0;
 133        legacy_serial_infos[index].irq_check_parent = irq_check_parent;
 134
 135        if (iotype == UPIO_TSI) {
 136                legacy_serial_ports[index].serial_in = tsi_serial_in;
 137                legacy_serial_ports[index].serial_out = tsi_serial_out;
 138        }
 139
 140        printk(KERN_DEBUG "Found legacy serial port %d for %s\n",
 141               index, np->full_name);
 142        printk(KERN_DEBUG "  %s=%llx, taddr=%llx, irq=%lx, clk=%d, speed=%d\n",
 143               (iotype == UPIO_PORT) ? "port" : "mem",
 144               (unsigned long long)base, (unsigned long long)taddr, irq,
 145               legacy_serial_ports[index].uartclk,
 146               legacy_serial_infos[index].speed);
 147
 148        return index;
 149}
 150
 151static int __init add_legacy_soc_port(struct device_node *np,
 152                                      struct device_node *soc_dev)
 153{
 154        u64 addr;
 155        const u32 *addrp;
 156        upf_t flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST | UPF_SHARE_IRQ
 157                | UPF_FIXED_PORT;
 158        struct device_node *tsi = of_get_parent(np);
 159
 160        /* We only support ports that have a clock frequency properly
 161         * encoded in the device-tree.
 162         */
 163        if (of_get_property(np, "clock-frequency", NULL) == NULL)
 164                return -1;
 165
 166        /* if reg-shift or offset, don't try to use it */
 167        if ((of_get_property(np, "reg-shift", NULL) != NULL) ||
 168                (of_get_property(np, "reg-offset", NULL) != NULL))
 169                return -1;
 170
 171        /* if rtas uses this device, don't try to use it as well */
 172        if (of_get_property(np, "used-by-rtas", NULL) != NULL)
 173                return -1;
 174
 175        /* Get the address */
 176        addrp = of_get_address(soc_dev, 0, NULL, NULL);
 177        if (addrp == NULL)
 178                return -1;
 179
 180        addr = of_translate_address(soc_dev, addrp);
 181        if (addr == OF_BAD_ADDR)
 182                return -1;
 183
 184        /* Add port, irq will be dealt with later. We passed a translated
 185         * IO port value. It will be fixed up later along with the irq
 186         */
 187        if (tsi && !strcmp(tsi->type, "tsi-bridge"))
 188                return add_legacy_port(np, -1, UPIO_TSI, addr, addr, NO_IRQ, flags, 0);
 189        else
 190                return add_legacy_port(np, -1, UPIO_MEM, addr, addr, NO_IRQ, flags, 0);
 191}
 192
 193static int __init add_legacy_isa_port(struct device_node *np,
 194                                      struct device_node *isa_brg)
 195{
 196        const __be32 *reg;
 197        const char *typep;
 198        int index = -1;
 199        u64 taddr;
 200
 201        DBG(" -> add_legacy_isa_port(%s)\n", np->full_name);
 202
 203        /* Get the ISA port number */
 204        reg = of_get_property(np, "reg", NULL);
 205        if (reg == NULL)
 206                return -1;
 207
 208        /* Verify it's an IO port, we don't support anything else */
 209        if (!(be32_to_cpu(reg[0]) & 0x00000001))
 210                return -1;
 211
 212        /* Now look for an "ibm,aix-loc" property that gives us ordering
 213         * if any...
 214         */
 215        typep = of_get_property(np, "ibm,aix-loc", NULL);
 216
 217        /* If we have a location index, then use it */
 218        if (typep && *typep == 'S')
 219                index = simple_strtol(typep+1, NULL, 0) - 1;
 220
 221        /* Translate ISA address. If it fails, we still register the port
 222         * with no translated address so that it can be picked up as an IO
 223         * port later by the serial driver
 224         */
 225        taddr = of_translate_address(np, reg);
 226        if (taddr == OF_BAD_ADDR)
 227                taddr = 0;
 228
 229        /* Add port, irq will be dealt with later */
 230        return add_legacy_port(np, index, UPIO_PORT, be32_to_cpu(reg[1]), taddr,
 231                               NO_IRQ, UPF_BOOT_AUTOCONF, 0);
 232
 233}
 234
 235#ifdef CONFIG_PCI
 236static int __init add_legacy_pci_port(struct device_node *np,
 237                                      struct device_node *pci_dev)
 238{
 239        u64 addr, base;
 240        const u32 *addrp;
 241        unsigned int flags;
 242        int iotype, index = -1, lindex = 0;
 243
 244        DBG(" -> add_legacy_pci_port(%s)\n", np->full_name);
 245
 246        /* We only support ports that have a clock frequency properly
 247         * encoded in the device-tree (that is have an fcode). Anything
 248         * else can't be used that early and will be normally probed by
 249         * the generic 8250_pci driver later on. The reason is that 8250
 250         * compatible UARTs on PCI need all sort of quirks (port offsets
 251         * etc...) that this code doesn't know about
 252         */
 253        if (of_get_property(np, "clock-frequency", NULL) == NULL)
 254                return -1;
 255
 256        /* Get the PCI address. Assume BAR 0 */
 257        addrp = of_get_pci_address(pci_dev, 0, NULL, &flags);
 258        if (addrp == NULL)
 259                return -1;
 260
 261        /* We only support BAR 0 for now */
 262        iotype = (flags & IORESOURCE_MEM) ? UPIO_MEM : UPIO_PORT;
 263        addr = of_translate_address(pci_dev, addrp);
 264        if (addr == OF_BAD_ADDR)
 265                return -1;
 266
 267        /* Set the IO base to the same as the translated address for MMIO,
 268         * or to the domain local IO base for PIO (it will be fixed up later)
 269         */
 270        if (iotype == UPIO_MEM)
 271                base = addr;
 272        else
 273                base = addrp[2];
 274
 275        /* Try to guess an index... If we have subdevices of the pci dev,
 276         * we get to their "reg" property
 277         */
 278        if (np != pci_dev) {
 279                const __be32 *reg = of_get_property(np, "reg", NULL);
 280                if (reg && (be32_to_cpup(reg) < 4))
 281                        index = lindex = be32_to_cpup(reg);
 282        }
 283
 284        /* Local index means it's the Nth port in the PCI chip. Unfortunately
 285         * the offset to add here is device specific. We know about those
 286         * EXAR ports and we default to the most common case. If your UART
 287         * doesn't work for these settings, you'll have to add your own special
 288         * cases here
 289         */
 290        if (of_device_is_compatible(pci_dev, "pci13a8,152") ||
 291            of_device_is_compatible(pci_dev, "pci13a8,154") ||
 292            of_device_is_compatible(pci_dev, "pci13a8,158")) {
 293                addr += 0x200 * lindex;
 294                base += 0x200 * lindex;
 295        } else {
 296                addr += 8 * lindex;
 297                base += 8 * lindex;
 298        }
 299
 300        /* Add port, irq will be dealt with later. We passed a translated
 301         * IO port value. It will be fixed up later along with the irq
 302         */
 303        return add_legacy_port(np, index, iotype, base, addr, NO_IRQ,
 304                               UPF_BOOT_AUTOCONF, np != pci_dev);
 305}
 306#endif
 307
 308static void __init setup_legacy_serial_console(int console)
 309{
 310        struct legacy_serial_info *info =
 311                &legacy_serial_infos[console];
 312        void __iomem *addr;
 313
 314        if (info->taddr == 0)
 315                return;
 316        addr = ioremap(info->taddr, 0x1000);
 317        if (addr == NULL)
 318                return;
 319        if (info->speed == 0)
 320                info->speed = udbg_probe_uart_speed(addr, info->clock);
 321        DBG("default console speed = %d\n", info->speed);
 322        udbg_init_uart(addr, info->speed, info->clock);
 323}
 324
 325/*
 326 * This is called very early, as part of setup_system() or eventually
 327 * setup_arch(), basically before anything else in this file. This function
 328 * will try to build a list of all the available 8250-compatible serial ports
 329 * in the machine using the Open Firmware device-tree. It currently only deals
 330 * with ISA and PCI busses but could be extended. It allows a very early boot
 331 * console to be initialized, that list is also used later to provide 8250 with
 332 * the machine non-PCI ports and to properly pick the default console port
 333 */
 334void __init find_legacy_serial_ports(void)
 335{
 336        struct device_node *np, *stdout = NULL;
 337        const char *path;
 338        int index;
 339
 340        DBG(" -> find_legacy_serial_port()\n");
 341
 342        /* Now find out if one of these is out firmware console */
 343        path = of_get_property(of_chosen, "linux,stdout-path", NULL);
 344        if (path != NULL) {
 345                stdout = of_find_node_by_path(path);
 346                if (stdout)
 347                        DBG("stdout is %s\n", stdout->full_name);
 348        } else {
 349                DBG(" no linux,stdout-path !\n");
 350        }
 351
 352        /* Iterate over all the 16550 ports, looking for known parents */
 353        for_each_compatible_node(np, "serial", "ns16550") {
 354                struct device_node *parent = of_get_parent(np);
 355                if (!parent)
 356                        continue;
 357                if (of_match_node(legacy_serial_parents, parent) != NULL) {
 358                        if (of_device_is_available(np)) {
 359                                index = add_legacy_soc_port(np, np);
 360                                if (index >= 0 && np == stdout)
 361                                        legacy_serial_console = index;
 362                        }
 363                }
 364                of_node_put(parent);
 365        }
 366
 367        /* Next, fill our array with ISA ports */
 368        for_each_node_by_type(np, "serial") {
 369                struct device_node *isa = of_get_parent(np);
 370                if (isa && !strcmp(isa->name, "isa")) {
 371                        index = add_legacy_isa_port(np, isa);
 372                        if (index >= 0 && np == stdout)
 373                                legacy_serial_console = index;
 374                }
 375                of_node_put(isa);
 376        }
 377
 378#ifdef CONFIG_PCI
 379        /* Next, try to locate PCI ports */
 380        for (np = NULL; (np = of_find_all_nodes(np));) {
 381                struct device_node *pci, *parent = of_get_parent(np);
 382                if (parent && !strcmp(parent->name, "isa")) {
 383                        of_node_put(parent);
 384                        continue;
 385                }
 386                if (strcmp(np->name, "serial") && strcmp(np->type, "serial")) {
 387                        of_node_put(parent);
 388                        continue;
 389                }
 390                /* Check for known pciclass, and also check wether we have
 391                 * a device with child nodes for ports or not
 392                 */
 393                if (of_device_is_compatible(np, "pciclass,0700") ||
 394                    of_device_is_compatible(np, "pciclass,070002"))
 395                        pci = np;
 396                else if (of_device_is_compatible(parent, "pciclass,0700") ||
 397                         of_device_is_compatible(parent, "pciclass,070002"))
 398                        pci = parent;
 399                else {
 400                        of_node_put(parent);
 401                        continue;
 402                }
 403                index = add_legacy_pci_port(np, pci);
 404                if (index >= 0 && np == stdout)
 405                        legacy_serial_console = index;
 406                of_node_put(parent);
 407        }
 408#endif
 409
 410        DBG("legacy_serial_console = %d\n", legacy_serial_console);
 411        if (legacy_serial_console >= 0)
 412                setup_legacy_serial_console(legacy_serial_console);
 413        DBG(" <- find_legacy_serial_port()\n");
 414}
 415
 416static struct platform_device serial_device = {
 417        .name   = "serial8250",
 418        .id     = PLAT8250_DEV_PLATFORM,
 419        .dev    = {
 420                .platform_data = legacy_serial_ports,
 421        },
 422};
 423
 424static void __init fixup_port_irq(int index,
 425                                  struct device_node *np,
 426                                  struct plat_serial8250_port *port)
 427{
 428        unsigned int virq;
 429
 430        DBG("fixup_port_irq(%d)\n", index);
 431
 432        virq = irq_of_parse_and_map(np, 0);
 433        if (virq == NO_IRQ && legacy_serial_infos[index].irq_check_parent) {
 434                np = of_get_parent(np);
 435                if (np == NULL)
 436                        return;
 437                virq = irq_of_parse_and_map(np, 0);
 438                of_node_put(np);
 439        }
 440        if (virq == NO_IRQ)
 441                return;
 442
 443        port->irq = virq;
 444
 445#ifdef CONFIG_SERIAL_8250_FSL
 446        if (of_device_is_compatible(np, "fsl,ns16550"))
 447                port->handle_irq = fsl8250_handle_irq;
 448#endif
 449}
 450
 451static void __init fixup_port_pio(int index,
 452                                  struct device_node *np,
 453                                  struct plat_serial8250_port *port)
 454{
 455#ifdef CONFIG_PCI
 456        struct pci_controller *hose;
 457
 458        DBG("fixup_port_pio(%d)\n", index);
 459
 460        hose = pci_find_hose_for_OF_device(np);
 461        if (hose) {
 462                unsigned long offset = (unsigned long)hose->io_base_virt -
 463#ifdef CONFIG_PPC64
 464                        pci_io_base;
 465#else
 466                        isa_io_base;
 467#endif
 468                DBG("port %d, IO %lx -> %lx\n",
 469                    index, port->iobase, port->iobase + offset);
 470                port->iobase += offset;
 471        }
 472#endif
 473}
 474
 475static void __init fixup_port_mmio(int index,
 476                                   struct device_node *np,
 477                                   struct plat_serial8250_port *port)
 478{
 479        DBG("fixup_port_mmio(%d)\n", index);
 480
 481        port->membase = ioremap(port->mapbase, 0x100);
 482}
 483
 484/*
 485 * This is called as an arch initcall, hopefully before the PCI bus is
 486 * probed and/or the 8250 driver loaded since we need to register our
 487 * platform devices before 8250 PCI ones are detected as some of them
 488 * must properly "override" the platform ones.
 489 *
 490 * This function fixes up the interrupt value for platform ports as it
 491 * couldn't be done earlier before interrupt maps have been parsed. It
 492 * also "corrects" the IO address for PIO ports for the same reason,
 493 * since earlier, the PHBs virtual IO space wasn't assigned yet. It then
 494 * registers all those platform ports for use by the 8250 driver when it
 495 * finally loads.
 496 */
 497static int __init serial_dev_init(void)
 498{
 499        int i;
 500
 501        if (legacy_serial_count == 0)
 502                return -ENODEV;
 503
 504        /*
 505         * Before we register the platform serial devices, we need
 506         * to fixup their interrupts and their IO ports.
 507         */
 508        DBG("Fixing serial ports interrupts and IO ports ...\n");
 509
 510        for (i = 0; i < legacy_serial_count; i++) {
 511                struct plat_serial8250_port *port = &legacy_serial_ports[i];
 512                struct device_node *np = legacy_serial_infos[i].np;
 513
 514                if (port->irq == NO_IRQ)
 515                        fixup_port_irq(i, np, port);
 516                if (port->iotype == UPIO_PORT)
 517                        fixup_port_pio(i, np, port);
 518                if ((port->iotype == UPIO_MEM) || (port->iotype == UPIO_TSI))
 519                        fixup_port_mmio(i, np, port);
 520        }
 521
 522        DBG("Registering platform serial ports\n");
 523
 524        return platform_device_register(&serial_device);
 525}
 526device_initcall(serial_dev_init);
 527
 528
 529#ifdef CONFIG_SERIAL_8250_CONSOLE
 530/*
 531 * This is called very early, as part of console_init() (typically just after
 532 * time_init()). This function is respondible for trying to find a good
 533 * default console on serial ports. It tries to match the open firmware
 534 * default output with one of the available serial console drivers that have
 535 * been probed earlier by find_legacy_serial_ports()
 536 */
 537static int __init check_legacy_serial_console(void)
 538{
 539        struct device_node *prom_stdout = NULL;
 540        int i, speed = 0, offset = 0;
 541        const char *name;
 542        const __be32 *spd;
 543
 544        DBG(" -> check_legacy_serial_console()\n");
 545
 546        /* The user has requested a console so this is already set up. */
 547        if (strstr(boot_command_line, "console=")) {
 548                DBG(" console was specified !\n");
 549                return -EBUSY;
 550        }
 551
 552        if (!of_chosen) {
 553                DBG(" of_chosen is NULL !\n");
 554                return -ENODEV;
 555        }
 556
 557        if (legacy_serial_console < 0) {
 558                DBG(" legacy_serial_console not found !\n");
 559                return -ENODEV;
 560        }
 561        /* We are getting a weird phandle from OF ... */
 562        /* ... So use the full path instead */
 563        name = of_get_property(of_chosen, "linux,stdout-path", NULL);
 564        if (name == NULL) {
 565                DBG(" no linux,stdout-path !\n");
 566                return -ENODEV;
 567        }
 568        prom_stdout = of_find_node_by_path(name);
 569        if (!prom_stdout) {
 570                DBG(" can't find stdout package %s !\n", name);
 571                return -ENODEV;
 572        }
 573        DBG("stdout is %s\n", prom_stdout->full_name);
 574
 575        name = of_get_property(prom_stdout, "name", NULL);
 576        if (!name) {
 577                DBG(" stdout package has no name !\n");
 578                goto not_found;
 579        }
 580        spd = of_get_property(prom_stdout, "current-speed", NULL);
 581        if (spd)
 582                speed = be32_to_cpup(spd);
 583
 584        if (strcmp(name, "serial") != 0)
 585                goto not_found;
 586
 587        /* Look for it in probed array */
 588        for (i = 0; i < legacy_serial_count; i++) {
 589                if (prom_stdout != legacy_serial_infos[i].np)
 590                        continue;
 591                offset = i;
 592                speed = legacy_serial_infos[i].speed;
 593                break;
 594        }
 595        if (i >= legacy_serial_count)
 596                goto not_found;
 597
 598        of_node_put(prom_stdout);
 599
 600        DBG("Found serial console at ttyS%d\n", offset);
 601
 602        if (speed) {
 603                static char __initdata opt[16];
 604                sprintf(opt, "%d", speed);
 605                return add_preferred_console("ttyS", offset, opt);
 606        } else
 607                return add_preferred_console("ttyS", offset, NULL);
 608
 609 not_found:
 610        DBG("No preferred console found !\n");
 611        of_node_put(prom_stdout);
 612        return -ENODEV;
 613}
 614console_initcall(check_legacy_serial_console);
 615
 616#endif /* CONFIG_SERIAL_8250_CONSOLE */
 617