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_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
  28 static struct plat_serial8250_port
  29 legacy_serial_ports[MAX_LEGACY_SERIAL_PORTS+1];
  30 static 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
  38 static struct of_device_id legacy_serial_parents[] __initdata = {
  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
  48 static unsigned int legacy_serial_count;
  49 static int legacy_serial_console = -1;
  50
  51 static 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
  62 static 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
  69 static 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 != NULL) {
 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
 151 static int __init add_legacy_soc_port(struct device_node *np,
 152                                       struct device_node *soc_dev)
 153 {
 154         u64 addr;
 155         const __be32 *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
 193 static 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          * Note: Don't even try on P8 lpc, we know it's not directly mapped
 226          */
 227         if (!of_device_is_compatible(isa_brg, "ibm,power8-lpc")) {
 228                 taddr = of_translate_address(np, reg);
 229                 if (taddr == OF_BAD_ADDR)
 230                         taddr = 0;
 231         } else
 232                 taddr = 0;
 233
 234         /* Add port, irq will be dealt with later */
 235         return add_legacy_port(np, index, UPIO_PORT, be32_to_cpu(reg[1]),
 236                                taddr, NO_IRQ, UPF_BOOT_AUTOCONF, 0);
 237
 238 }
 239
 240 #ifdef CONFIG_PCI
 241 static int __init add_legacy_pci_port(struct device_node *np,
 242                                       struct device_node *pci_dev)
 243 {
 244         u64 addr, base;
 245         const __be32 *addrp;
 246         unsigned int flags;
 247         int iotype, index = -1, lindex = 0;
 248
 249         DBG(" -> add_legacy_pci_port(%s)\n", np->full_name);
 250
 251         /* We only support ports that have a clock frequency properly
 252          * encoded in the device-tree (that is have an fcode). Anything
 253          * else can't be used that early and will be normally probed by
 254          * the generic 8250_pci driver later on. The reason is that 8250
 255          * compatible UARTs on PCI need all sort of quirks (port offsets
 256          * etc...) that this code doesn't know about
 257          */
 258         if (of_get_property(np, "clock-frequency", NULL) == NULL)
 259                 return -1;
 260
 261         /* Get the PCI address. Assume BAR 0 */
 262         addrp = of_get_pci_address(pci_dev, 0, NULL, &flags);
 263         if (addrp == NULL)
 264                 return -1;
 265
 266         /* We only support BAR 0 for now */
 267         iotype = (flags & IORESOURCE_MEM) ? UPIO_MEM : UPIO_PORT;
 268         addr = of_translate_address(pci_dev, addrp);
 269         if (addr == OF_BAD_ADDR)
 270                 return -1;
 271
 272         /* Set the IO base to the same as the translated address for MMIO,
 273          * or to the domain local IO base for PIO (it will be fixed up later)
 274          */
 275         if (iotype == UPIO_MEM)
 276                 base = addr;
 277         else
 278                 base = of_read_number(&addrp[2], 1);
 279
 280         /* Try to guess an index... If we have subdevices of the pci dev,
 281          * we get to their "reg" property
 282          */
 283         if (np != pci_dev) {
 284                 const __be32 *reg = of_get_property(np, "reg", NULL);
 285                 if (reg && (be32_to_cpup(reg) < 4))
 286                         index = lindex = be32_to_cpup(reg);
 287         }
 288
 289         /* Local index means it's the Nth port in the PCI chip. Unfortunately
 290          * the offset to add here is device specific. We know about those
 291          * EXAR ports and we default to the most common case. If your UART
 292          * doesn't work for these settings, you'll have to add your own special
 293          * cases here
 294          */
 295         if (of_device_is_compatible(pci_dev, "pci13a8,152") ||
 296             of_device_is_compatible(pci_dev, "pci13a8,154") ||
 297             of_device_is_compatible(pci_dev, "pci13a8,158")) {
 298                 addr += 0x200 * lindex;
 299                 base += 0x200 * lindex;
 300         } else {
 301                 addr += 8 * lindex;
 302                 base += 8 * lindex;
 303         }
 304
 305         /* Add port, irq will be dealt with later. We passed a translated
 306          * IO port value. It will be fixed up later along with the irq
 307          */
 308         return add_legacy_port(np, index, iotype, base, addr, NO_IRQ,
 309                                UPF_BOOT_AUTOCONF, np != pci_dev);
 310 }
 311 #endif
 312
 313 static void __init setup_legacy_serial_console(int console)
 314 {
 315         struct legacy_serial_info *info = &legacy_serial_infos[console];
 316         struct plat_serial8250_port *port = &legacy_serial_ports[console];
 317         void __iomem *addr;
 318
 319         /* Check if a translated MMIO address has been found */
 320         if (info->taddr) {
 321                 addr = ioremap(info->taddr, 0x1000);
 322                 if (addr == NULL)
 323                         return;
 324                 udbg_uart_init_mmio(addr, 1);
 325         } else {
 326                 /* Check if it's PIO and we support untranslated PIO */
 327                 if (port->iotype == UPIO_PORT && isa_io_special)
 328                         udbg_uart_init_pio(port->iobase, 1);
 329                 else
 330                         return;
 331         }
 332
 333         /* Try to query the current speed */
 334         if (info->speed == 0)
 335                 info->speed = udbg_probe_uart_speed(info->clock);
 336
 337         /* Set it up */
 338         DBG("default console speed = %d\n", info->speed);
 339         udbg_uart_setup(info->speed, info->clock);
 340 }
 341
 342 /*
 343  * This is called very early, as part of setup_system() or eventually
 344  * setup_arch(), basically before anything else in this file. This function
 345  * will try to build a list of all the available 8250-compatible serial ports
 346  * in the machine using the Open Firmware device-tree. It currently only deals
 347  * with ISA and PCI busses but could be extended. It allows a very early boot
 348  * console to be initialized, that list is also used later to provide 8250 with
 349  * the machine non-PCI ports and to properly pick the default console port
 350  */
 351 void __init find_legacy_serial_ports(void)
 352 {
 353         struct device_node *np, *stdout = NULL;
 354         const char *path;
 355         int index;
 356
 357         DBG(" -> find_legacy_serial_port()\n");
 358
 359         /* Now find out if one of these is out firmware console */
 360         path = of_get_property(of_chosen, "linux,stdout-path", NULL);
 361         if (path != NULL) {
 362                 stdout = of_find_node_by_path(path);
 363                 if (stdout)
 364                         DBG("stdout is %s\n", stdout->full_name);
 365         } else {
 366                 DBG(" no linux,stdout-path !\n");
 367         }
 368
 369         /* Iterate over all the 16550 ports, looking for known parents */
 370         for_each_compatible_node(np, "serial", "ns16550") {
 371                 struct device_node *parent = of_get_parent(np);
 372                 if (!parent)
 373                         continue;
 374                 if (of_match_node(legacy_serial_parents, parent) != NULL) {
 375                         if (of_device_is_available(np)) {
 376                                 index = add_legacy_soc_port(np, np);
 377                                 if (index >= 0 && np == stdout)
 378                                         legacy_serial_console = index;
 379                         }
 380                 }
 381                 of_node_put(parent);
 382         }
 383
 384         /* Next, fill our array with ISA ports */
 385         for_each_node_by_type(np, "serial") {
 386                 struct device_node *isa = of_get_parent(np);
 387                 if (isa && (!strcmp(isa->name, "isa") ||
 388                             !strcmp(isa->name, "lpc"))) {
 389                         if (of_device_is_available(np)) {
 390                                 index = add_legacy_isa_port(np, isa);
 391                                 if (index >= 0 && np == stdout)
 392                                         legacy_serial_console = index;
 393                         }
 394                 }
 395                 of_node_put(isa);
 396         }
 397
 398 #ifdef CONFIG_PCI
 399         /* Next, try to locate PCI ports */
 400         for (np = NULL; (np = of_find_all_nodes(np));) {
 401                 struct device_node *pci, *parent = of_get_parent(np);
 402                 if (parent && !strcmp(parent->name, "isa")) {
 403                         of_node_put(parent);
 404                         continue;
 405                 }
 406                 if (strcmp(np->name, "serial") && strcmp(np->type, "serial")) {
 407                         of_node_put(parent);
 408                         continue;
 409                 }
 410                 /* Check for known pciclass, and also check whether we have
 411                  * a device with child nodes for ports or not
 412                  */
 413                 if (of_device_is_compatible(np, "pciclass,0700") ||
 414                     of_device_is_compatible(np, "pciclass,070002"))
 415                         pci = np;
 416                 else if (of_device_is_compatible(parent, "pciclass,0700") ||
 417                          of_device_is_compatible(parent, "pciclass,070002"))
 418                         pci = parent;
 419                 else {
 420                         of_node_put(parent);
 421                         continue;
 422                 }
 423                 index = add_legacy_pci_port(np, pci);
 424                 if (index >= 0 && np == stdout)
 425                         legacy_serial_console = index;
 426                 of_node_put(parent);
 427         }
 428 #endif
 429
 430         DBG("legacy_serial_console = %d\n", legacy_serial_console);
 431         if (legacy_serial_console >= 0)
 432                 setup_legacy_serial_console(legacy_serial_console);
 433         DBG(" <- find_legacy_serial_port()\n");
 434 }
 435
 436 static struct platform_device serial_device = {
 437         .name   = "serial8250",
 438         .id     = PLAT8250_DEV_PLATFORM,
 439         .dev    = {
 440                 .platform_data = legacy_serial_ports,
 441         },
 442 };
 443
 444 static void __init fixup_port_irq(int index,
 445                                   struct device_node *np,
 446                                   struct plat_serial8250_port *port)
 447 {
 448         unsigned int virq;
 449
 450         DBG("fixup_port_irq(%d)\n", index);
 451
 452         virq = irq_of_parse_and_map(np, 0);
 453         if (virq == NO_IRQ && legacy_serial_infos[index].irq_check_parent) {
 454                 np = of_get_parent(np);
 455                 if (np == NULL)
 456                         return;
 457                 virq = irq_of_parse_and_map(np, 0);
 458                 of_node_put(np);
 459         }
 460         if (virq == NO_IRQ)
 461                 return;
 462
 463         port->irq = virq;
 464
 465 #ifdef CONFIG_SERIAL_8250_FSL
 466         if (of_device_is_compatible(np, "fsl,ns16550"))
 467                 port->handle_irq = fsl8250_handle_irq;
 468 #endif
 469 }
 470
 471 static void __init fixup_port_pio(int index,
 472                                   struct device_node *np,
 473                                   struct plat_serial8250_port *port)
 474 {
 475 #ifdef CONFIG_PCI
 476         struct pci_controller *hose;
 477
 478         DBG("fixup_port_pio(%d)\n", index);
 479
 480         hose = pci_find_hose_for_OF_device(np);
 481         if (hose) {
 482                 unsigned long offset = (unsigned long)hose->io_base_virt -
 483 #ifdef CONFIG_PPC64
 484                         pci_io_base;
 485 #else
 486                         isa_io_base;
 487 #endif
 488                 DBG("port %d, IO %lx -> %lx\n",
 489                     index, port->iobase, port->iobase + offset);
 490                 port->iobase += offset;
 491         }
 492 #endif
 493 }
 494
 495 static void __init fixup_port_mmio(int index,
 496                                    struct device_node *np,
 497                                    struct plat_serial8250_port *port)
 498 {
 499         DBG("fixup_port_mmio(%d)\n", index);
 500
 501         port->membase = ioremap(port->mapbase, 0x100);
 502 }
 503
 504 /*
 505  * This is called as an arch initcall, hopefully before the PCI bus is
 506  * probed and/or the 8250 driver loaded since we need to register our
 507  * platform devices before 8250 PCI ones are detected as some of them
 508  * must properly "override" the platform ones.
 509  *
 510  * This function fixes up the interrupt value for platform ports as it
 511  * couldn't be done earlier before interrupt maps have been parsed. It
 512  * also "corrects" the IO address for PIO ports for the same reason,
 513  * since earlier, the PHBs virtual IO space wasn't assigned yet. It then
 514  * registers all those platform ports for use by the 8250 driver when it
 515  * finally loads.
 516  */
 517 static int __init serial_dev_init(void)
 518 {
 519         int i;
 520
 521         if (legacy_serial_count == 0)
 522                 return -ENODEV;
 523
 524         /*
 525          * Before we register the platform serial devices, we need
 526          * to fixup their interrupts and their IO ports.
 527          */
 528         DBG("Fixing serial ports interrupts and IO ports ...\n");
 529
 530         for (i = 0; i < legacy_serial_count; i++) {
 531                 struct plat_serial8250_port *port = &legacy_serial_ports[i];
 532                 struct device_node *np = legacy_serial_infos[i].np;
 533
 534                 if (port->irq == NO_IRQ)
 535                         fixup_port_irq(i, np, port);
 536                 if (port->iotype == UPIO_PORT)
 537                         fixup_port_pio(i, np, port);
 538                 if ((port->iotype == UPIO_MEM) || (port->iotype == UPIO_TSI))
 539                         fixup_port_mmio(i, np, port);
 540         }
 541
 542         DBG("Registering platform serial ports\n");
 543
 544         return platform_device_register(&serial_device);
 545 }
 546 device_initcall(serial_dev_init);
 547
 548
 549 #ifdef CONFIG_SERIAL_8250_CONSOLE
 550 /*
 551  * This is called very early, as part of console_init() (typically just after
 552  * time_init()). This function is respondible for trying to find a good
 553  * default console on serial ports. It tries to match the open firmware
 554  * default output with one of the available serial console drivers that have
 555  * been probed earlier by find_legacy_serial_ports()
 556  */
 557 static int __init check_legacy_serial_console(void)
 558 {
 559         struct device_node *prom_stdout = NULL;
 560         int i, speed = 0, offset = 0;
 561         const char *name;
 562         const __be32 *spd;
 563
 564         DBG(" -> check_legacy_serial_console()\n");
 565
 566         /* The user has requested a console so this is already set up. */
 567         if (strstr(boot_command_line, "console=")) {
 568                 DBG(" console was specified !\n");
 569                 return -EBUSY;
 570         }
 571
 572         if (!of_chosen) {
 573                 DBG(" of_chosen is NULL !\n");
 574                 return -ENODEV;
 575         }
 576
 577         if (legacy_serial_console < 0) {
 578                 DBG(" legacy_serial_console not found !\n");
 579                 return -ENODEV;
 580         }
 581         /* We are getting a weird phandle from OF ... */
 582         /* ... So use the full path instead */
 583         name = of_get_property(of_chosen, "linux,stdout-path", NULL);
 584         if (name == NULL) {
 585                 DBG(" no linux,stdout-path !\n");
 586                 return -ENODEV;
 587         }
 588         prom_stdout = of_find_node_by_path(name);
 589         if (!prom_stdout) {
 590                 DBG(" can't find stdout package %s !\n", name);
 591                 return -ENODEV;
 592         }
 593         DBG("stdout is %s\n", prom_stdout->full_name);
 594
 595         name = of_get_property(prom_stdout, "name", NULL);
 596         if (!name) {
 597                 DBG(" stdout package has no name !\n");
 598                 goto not_found;
 599         }
 600         spd = of_get_property(prom_stdout, "current-speed", NULL);
 601         if (spd)
 602                 speed = be32_to_cpup(spd);
 603
 604         if (strcmp(name, "serial") != 0)
 605                 goto not_found;
 606
 607         /* Look for it in probed array */
 608         for (i = 0; i < legacy_serial_count; i++) {
 609                 if (prom_stdout != legacy_serial_infos[i].np)
 610                         continue;
 611                 offset = i;
 612                 speed = legacy_serial_infos[i].speed;
 613                 break;
 614         }
 615         if (i >= legacy_serial_count)
 616                 goto not_found;
 617
 618         of_node_put(prom_stdout);
 619
 620         DBG("Found serial console at ttyS%d\n", offset);
 621
 622         if (speed) {
 623                 static char __initdata opt[16];
 624                 sprintf(opt, "%d", speed);
 625                 return add_preferred_console("ttyS", offset, opt);
 626         } else
 627                 return add_preferred_console("ttyS", offset, NULL);
 628
 629  not_found:
 630         DBG("No preferred console found !\n");
 631         of_node_put(prom_stdout);
 632         return -ENODEV;
 633 }
 634 console_initcall(check_legacy_serial_console);
 635
 636 #endif /* CONFIG_SERIAL_8250_CONSOLE */