arch/powerpc/kernel/legacy_serial.c

   1 #include <linux/kernel.h>
   2 #include <linux/serial.h>
   3 #include <linux/serial_8250.h>
   4 #include <linux/serial_core.h>
   5 #include <linux/console.h>
   6 #include <linux/pci.h>
   7 #include <asm/io.h>
   8 #include <asm/mmu.h>
   9 #include <asm/prom.h>
  10 #include <asm/serial.h>
  11 #include <asm/udbg.h>
  12 #include <asm/pci-bridge.h>
  13 #include <asm/ppc-pci.h>
  14
  15 #undef DEBUG
  16
  17 #ifdef DEBUG
  18 #define DBG(fmt...) do { printk(fmt); } while(0)
  19 #else
  20 #define DBG(fmt...) do { } while(0)
  21 #endif
  22
  23 #define MAX_LEGACY_SERIAL_PORTS 8
  24
  25 static struct plat_serial8250_port
  26 legacy_serial_ports[MAX_LEGACY_SERIAL_PORTS+1];
  27 static struct legacy_serial_info {
  28         struct device_node              *np;
  29         unsigned int                    speed;
  30         unsigned int                    clock;
  31         int                             irq_check_parent;
  32         phys_addr_t                     taddr;
  33 } legacy_serial_infos[MAX_LEGACY_SERIAL_PORTS];
  34 static unsigned int legacy_serial_count;
  35 static int legacy_serial_console = -1;
  36
  37 static int __init add_legacy_port(struct device_node *np, int want_index,
  38                                   int iotype, phys_addr_t base,
  39                                   phys_addr_t taddr, unsigned long irq,
  40                                   upf_t flags, int irq_check_parent)
  41 {
  42         const u32 *clk, *spd;
  43         u32 clock = BASE_BAUD * 16;
  44         int index;
  45
  46         /* get clock freq. if present */
  47         clk = of_get_property(np, "clock-frequency", NULL);
  48         if (clk && *clk)
  49                 clock = *clk;
  50
  51         /* get default speed if present */
  52         spd = of_get_property(np, "current-speed", NULL);
  53
  54         /* If we have a location index, then try to use it */
  55         if (want_index >= 0 && want_index < MAX_LEGACY_SERIAL_PORTS)
  56                 index = want_index;
  57         else
  58                 index = legacy_serial_count;
  59
  60         /* if our index is still out of range, that mean that
  61          * array is full, we could scan for a free slot but that
  62          * make little sense to bother, just skip the port
  63          */
  64         if (index >= MAX_LEGACY_SERIAL_PORTS)
  65                 return -1;
  66         if (index >= legacy_serial_count)
  67                 legacy_serial_count = index + 1;
  68
  69         /* Check if there is a port who already claimed our slot */
  70         if (legacy_serial_infos[index].np != 0) {
  71                 /* if we still have some room, move it, else override */
  72                 if (legacy_serial_count < MAX_LEGACY_SERIAL_PORTS) {
  73                         printk(KERN_DEBUG "Moved legacy port %d -> %d\n",
  74                                index, legacy_serial_count);
  75                         legacy_serial_ports[legacy_serial_count] =
  76                                 legacy_serial_ports[index];
  77                         legacy_serial_infos[legacy_serial_count] =
  78                                 legacy_serial_infos[index];
  79                         legacy_serial_count++;
  80                 } else {
  81                         printk(KERN_DEBUG "Replacing legacy port %d\n", index);
  82                 }
  83         }
  84
  85         /* Now fill the entry */
  86         memset(&legacy_serial_ports[index], 0,
  87                sizeof(struct plat_serial8250_port));
  88         if (iotype == UPIO_PORT)
  89                 legacy_serial_ports[index].iobase = base;
  90         else
  91                 legacy_serial_ports[index].mapbase = base;
  92         legacy_serial_ports[index].iotype = iotype;
  93         legacy_serial_ports[index].uartclk = clock;
  94         legacy_serial_ports[index].irq = irq;
  95         legacy_serial_ports[index].flags = flags;
  96         legacy_serial_infos[index].taddr = taddr;
  97         legacy_serial_infos[index].np = of_node_get(np);
  98         legacy_serial_infos[index].clock = clock;
  99         legacy_serial_infos[index].speed = spd ? *spd : 0;
 100         legacy_serial_infos[index].irq_check_parent = irq_check_parent;
 101
 102         printk(KERN_DEBUG "Found legacy serial port %d for %s\n",
 103                index, np->full_name);
 104         printk(KERN_DEBUG "  %s=%llx, taddr=%llx, irq=%lx, clk=%d, speed=%d\n",
 105                (iotype == UPIO_PORT) ? "port" : "mem",
 106                (unsigned long long)base, (unsigned long long)taddr, irq,
 107                legacy_serial_ports[index].uartclk,
 108                legacy_serial_infos[index].speed);
 109
 110         return index;
 111 }
 112
 113 static int __init add_legacy_soc_port(struct device_node *np,
 114                                       struct device_node *soc_dev)
 115 {
 116         u64 addr;
 117         const u32 *addrp;
 118         upf_t flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST | UPF_SHARE_IRQ
 119                 | UPF_FIXED_PORT;
 120         struct device_node *tsi = of_get_parent(np);
 121
 122         /* We only support ports that have a clock frequency properly
 123          * encoded in the device-tree.
 124          */
 125         if (of_get_property(np, "clock-frequency", NULL) == NULL)
 126                 return -1;
 127
 128         /* if rtas uses this device, don't try to use it as well */
 129         if (of_get_property(np, "used-by-rtas", NULL) != NULL)
 130                 return -1;
 131
 132         /* Get the address */
 133         addrp = of_get_address(soc_dev, 0, NULL, NULL);
 134         if (addrp == NULL)
 135                 return -1;
 136
 137         addr = of_translate_address(soc_dev, addrp);
 138         if (addr == OF_BAD_ADDR)
 139                 return -1;
 140
 141         /* Add port, irq will be dealt with later. We passed a translated
 142          * IO port value. It will be fixed up later along with the irq
 143          */
 144         if (tsi && !strcmp(tsi->type, "tsi-bridge"))
 145                 return add_legacy_port(np, -1, UPIO_TSI, addr, addr, NO_IRQ, flags, 0);
 146         else
 147                 return add_legacy_port(np, -1, UPIO_MEM, addr, addr, NO_IRQ, flags, 0);
 148 }
 149
 150 static int __init add_legacy_isa_port(struct device_node *np,
 151                                       struct device_node *isa_brg)
 152 {
 153         const u32 *reg;
 154         const char *typep;
 155         int index = -1;
 156         u64 taddr;
 157
 158         DBG(" -> add_legacy_isa_port(%s)\n", np->full_name);
 159
 160         /* Get the ISA port number */
 161         reg = of_get_property(np, "reg", NULL);
 162         if (reg == NULL)
 163                 return -1;
 164
 165         /* Verify it's an IO port, we don't support anything else */
 166         if (!(reg[0] & 0x00000001))
 167                 return -1;
 168
 169         /* Now look for an "ibm,aix-loc" property that gives us ordering
 170          * if any...
 171          */
 172         typep = of_get_property(np, "ibm,aix-loc", NULL);
 173
 174         /* If we have a location index, then use it */
 175         if (typep && *typep == 'S')
 176                 index = simple_strtol(typep+1, NULL, 0) - 1;
 177
 178         /* Translate ISA address. If it fails, we still register the port
 179          * with no translated address so that it can be picked up as an IO
 180          * port later by the serial driver
 181          */
 182         taddr = of_translate_address(np, reg);
 183         if (taddr == OF_BAD_ADDR)
 184                 taddr = 0;
 185
 186         /* Add port, irq will be dealt with later */
 187         return add_legacy_port(np, index, UPIO_PORT, reg[1], taddr,
 188                                NO_IRQ, UPF_BOOT_AUTOCONF, 0);
 189
 190 }
 191
 192 #ifdef CONFIG_PCI
 193 static int __init add_legacy_pci_port(struct device_node *np,
 194                                       struct device_node *pci_dev)
 195 {
 196         u64 addr, base;
 197         const u32 *addrp;
 198         unsigned int flags;
 199         int iotype, index = -1, lindex = 0;
 200
 201         DBG(" -> add_legacy_pci_port(%s)\n", np->full_name);
 202
 203         /* We only support ports that have a clock frequency properly
 204          * encoded in the device-tree (that is have an fcode). Anything
 205          * else can't be used that early and will be normally probed by
 206          * the generic 8250_pci driver later on. The reason is that 8250
 207          * compatible UARTs on PCI need all sort of quirks (port offsets
 208          * etc...) that this code doesn't know about
 209          */
 210         if (of_get_property(np, "clock-frequency", NULL) == NULL)
 211                 return -1;
 212
 213         /* Get the PCI address. Assume BAR 0 */
 214         addrp = of_get_pci_address(pci_dev, 0, NULL, &flags);
 215         if (addrp == NULL)
 216                 return -1;
 217
 218         /* We only support BAR 0 for now */
 219         iotype = (flags & IORESOURCE_MEM) ? UPIO_MEM : UPIO_PORT;
 220         addr = of_translate_address(pci_dev, addrp);
 221         if (addr == OF_BAD_ADDR)
 222                 return -1;
 223
 224         /* Set the IO base to the same as the translated address for MMIO,
 225          * or to the domain local IO base for PIO (it will be fixed up later)
 226          */
 227         if (iotype == UPIO_MEM)
 228                 base = addr;
 229         else
 230                 base = addrp[2];
 231
 232         /* Try to guess an index... If we have subdevices of the pci dev,
 233          * we get to their "reg" property
 234          */
 235         if (np != pci_dev) {
 236                 const u32 *reg = of_get_property(np, "reg", NULL);
 237                 if (reg && (*reg < 4))
 238                         index = lindex = *reg;
 239         }
 240
 241         /* Local index means it's the Nth port in the PCI chip. Unfortunately
 242          * the offset to add here is device specific. We know about those
 243          * EXAR ports and we default to the most common case. If your UART
 244          * doesn't work for these settings, you'll have to add your own special
 245          * cases here
 246          */
 247         if (of_device_is_compatible(pci_dev, "pci13a8,152") ||
 248             of_device_is_compatible(pci_dev, "pci13a8,154") ||
 249             of_device_is_compatible(pci_dev, "pci13a8,158")) {
 250                 addr += 0x200 * lindex;
 251                 base += 0x200 * lindex;
 252         } else {
 253                 addr += 8 * lindex;
 254                 base += 8 * lindex;
 255         }
 256
 257         /* Add port, irq will be dealt with later. We passed a translated
 258          * IO port value. It will be fixed up later along with the irq
 259          */
 260         return add_legacy_port(np, index, iotype, base, addr, NO_IRQ,
 261                                UPF_BOOT_AUTOCONF, np != pci_dev);
 262 }
 263 #endif
 264
 265 static void __init setup_legacy_serial_console(int console)
 266 {
 267         struct legacy_serial_info *info =
 268                 &legacy_serial_infos[console];
 269         void __iomem *addr;
 270
 271         if (info->taddr == 0)
 272                 return;
 273         addr = ioremap(info->taddr, 0x1000);
 274         if (addr == NULL)
 275                 return;
 276         if (info->speed == 0)
 277                 info->speed = udbg_probe_uart_speed(addr, info->clock);
 278         DBG("default console speed = %d\n", info->speed);
 279         udbg_init_uart(addr, info->speed, info->clock);
 280 }
 281
 282 /*
 283  * This is called very early, as part of setup_system() or eventually
 284  * setup_arch(), basically before anything else in this file. This function
 285  * will try to build a list of all the available 8250-compatible serial ports
 286  * in the machine using the Open Firmware device-tree. It currently only deals
 287  * with ISA and PCI busses but could be extended. It allows a very early boot
 288  * console to be initialized, that list is also used later to provide 8250 with
 289  * the machine non-PCI ports and to properly pick the default console port
 290  */
 291 void __init find_legacy_serial_ports(void)
 292 {
 293         struct device_node *np, *stdout = NULL;
 294         const char *path;
 295         int index;
 296
 297         DBG(" -> find_legacy_serial_port()\n");
 298
 299         /* Now find out if one of these is out firmware console */
 300         path = of_get_property(of_chosen, "linux,stdout-path", NULL);
 301         if (path != NULL) {
 302                 stdout = of_find_node_by_path(path);
 303                 if (stdout)
 304                         DBG("stdout is %s\n", stdout->full_name);
 305         } else {
 306                 DBG(" no linux,stdout-path !\n");
 307         }
 308
 309         /* First fill our array with SOC ports */
 310         for (np = NULL; (np = of_find_compatible_node(np, "serial", "ns16550")) != NULL;) {
 311                 struct device_node *soc = of_get_parent(np);
 312                 if (soc && !strcmp(soc->type, "soc")) {
 313                         index = add_legacy_soc_port(np, np);
 314                         if (index >= 0 && np == stdout)
 315                                 legacy_serial_console = index;
 316                 }
 317                 of_node_put(soc);
 318         }
 319
 320         /* First fill our array with ISA ports */
 321         for (np = NULL; (np = of_find_node_by_type(np, "serial"));) {
 322                 struct device_node *isa = of_get_parent(np);
 323                 if (isa && !strcmp(isa->name, "isa")) {
 324                         index = add_legacy_isa_port(np, isa);
 325                         if (index >= 0 && np == stdout)
 326                                 legacy_serial_console = index;
 327                 }
 328                 of_node_put(isa);
 329         }
 330
 331         /* First fill our array with tsi-bridge ports */
 332         for (np = NULL; (np = of_find_compatible_node(np, "serial", "ns16550")) != NULL;) {
 333                 struct device_node *tsi = of_get_parent(np);
 334                 if (tsi && !strcmp(tsi->type, "tsi-bridge")) {
 335                         index = add_legacy_soc_port(np, np);
 336                         if (index >= 0 && np == stdout)
 337                                 legacy_serial_console = index;
 338                 }
 339                 of_node_put(tsi);
 340         }
 341
 342         /* First fill our array with opb bus ports */
 343         for (np = NULL; (np = of_find_compatible_node(np, "serial", "ns16550")) != NULL;) {
 344                 struct device_node *opb = of_get_parent(np);
 345                 if (opb && (!strcmp(opb->type, "opb") ||
 346                             of_device_is_compatible(opb, "ibm,opb"))) {
 347                         index = add_legacy_soc_port(np, np);
 348                         if (index >= 0 && np == stdout)
 349                                 legacy_serial_console = index;
 350                 }
 351                 of_node_put(opb);
 352         }
 353
 354 #ifdef CONFIG_PCI
 355         /* Next, try to locate PCI ports */
 356         for (np = NULL; (np = of_find_all_nodes(np));) {
 357                 struct device_node *pci, *parent = of_get_parent(np);
 358                 if (parent && !strcmp(parent->name, "isa")) {
 359                         of_node_put(parent);
 360                         continue;
 361                 }
 362                 if (strcmp(np->name, "serial") && strcmp(np->type, "serial")) {
 363                         of_node_put(parent);
 364                         continue;
 365                 }
 366                 /* Check for known pciclass, and also check wether we have
 367                  * a device with child nodes for ports or not
 368                  */
 369                 if (of_device_is_compatible(np, "pciclass,0700") ||
 370                     of_device_is_compatible(np, "pciclass,070002"))
 371                         pci = np;
 372                 else if (of_device_is_compatible(parent, "pciclass,0700") ||
 373                          of_device_is_compatible(parent, "pciclass,070002"))
 374                         pci = parent;
 375                 else {
 376                         of_node_put(parent);
 377                         continue;
 378                 }
 379                 index = add_legacy_pci_port(np, pci);
 380                 if (index >= 0 && np == stdout)
 381                         legacy_serial_console = index;
 382                 of_node_put(parent);
 383         }
 384 #endif
 385
 386         DBG("legacy_serial_console = %d\n", legacy_serial_console);
 387         if (legacy_serial_console >= 0)
 388                 setup_legacy_serial_console(legacy_serial_console);
 389         DBG(" <- find_legacy_serial_port()\n");
 390 }
 391
 392 static struct platform_device serial_device = {
 393         .name   = "serial8250",
 394         .id     = PLAT8250_DEV_PLATFORM,
 395         .dev    = {
 396                 .platform_data = legacy_serial_ports,
 397         },
 398 };
 399
 400 static void __init fixup_port_irq(int index,
 401                                   struct device_node *np,
 402                                   struct plat_serial8250_port *port)
 403 {
 404         unsigned int virq;
 405
 406         DBG("fixup_port_irq(%d)\n", index);
 407
 408         virq = irq_of_parse_and_map(np, 0);
 409         if (virq == NO_IRQ && legacy_serial_infos[index].irq_check_parent) {
 410                 np = of_get_parent(np);
 411                 if (np == NULL)
 412                         return;
 413                 virq = irq_of_parse_and_map(np, 0);
 414                 of_node_put(np);
 415         }
 416         if (virq == NO_IRQ)
 417                 return;
 418
 419         port->irq = virq;
 420 }
 421
 422 static void __init fixup_port_pio(int index,
 423                                   struct device_node *np,
 424                                   struct plat_serial8250_port *port)
 425 {
 426 #ifdef CONFIG_PCI
 427         struct pci_controller *hose;
 428
 429         DBG("fixup_port_pio(%d)\n", index);
 430
 431         hose = pci_find_hose_for_OF_device(np);
 432         if (hose) {
 433                 unsigned long offset = (unsigned long)hose->io_base_virt -
 434 #ifdef CONFIG_PPC64
 435                         pci_io_base;
 436 #else
 437                         isa_io_base;
 438 #endif
 439                 DBG("port %d, IO %lx -> %lx\n",
 440                     index, port->iobase, port->iobase + offset);
 441                 port->iobase += offset;
 442         }
 443 #endif
 444 }
 445
 446 static void __init fixup_port_mmio(int index,
 447                                    struct device_node *np,
 448                                    struct plat_serial8250_port *port)
 449 {
 450         DBG("fixup_port_mmio(%d)\n", index);
 451
 452         port->membase = ioremap(port->mapbase, 0x100);
 453 }
 454
 455 /*
 456  * This is called as an arch initcall, hopefully before the PCI bus is
 457  * probed and/or the 8250 driver loaded since we need to register our
 458  * platform devices before 8250 PCI ones are detected as some of them
 459  * must properly "override" the platform ones.
 460  *
 461  * This function fixes up the interrupt value for platform ports as it
 462  * couldn't be done earlier before interrupt maps have been parsed. It
 463  * also "corrects" the IO address for PIO ports for the same reason,
 464  * since earlier, the PHBs virtual IO space wasn't assigned yet. It then
 465  * registers all those platform ports for use by the 8250 driver when it
 466  * finally loads.
 467  */
 468 static int __init serial_dev_init(void)
 469 {
 470         int i;
 471
 472         if (legacy_serial_count == 0)
 473                 return -ENODEV;
 474
 475         /*
 476          * Before we register the platfrom serial devices, we need
 477          * to fixup their interrupts and their IO ports.
 478          */
 479         DBG("Fixing serial ports interrupts and IO ports ...\n");
 480
 481         for (i = 0; i < legacy_serial_count; i++) {
 482                 struct plat_serial8250_port *port = &legacy_serial_ports[i];
 483                 struct device_node *np = legacy_serial_infos[i].np;
 484
 485                 if (port->irq == NO_IRQ)
 486                         fixup_port_irq(i, np, port);
 487                 if (port->iotype == UPIO_PORT)
 488                         fixup_port_pio(i, np, port);
 489                 if ((port->iotype == UPIO_MEM) || (port->iotype == UPIO_TSI))
 490                         fixup_port_mmio(i, np, port);
 491         }
 492
 493         DBG("Registering platform serial ports\n");
 494
 495         return platform_device_register(&serial_device);
 496 }
 497 device_initcall(serial_dev_init);
 498
 499
 500 /*
 501  * This is called very early, as part of console_init() (typically just after
 502  * time_init()). This function is respondible for trying to find a good
 503  * default console on serial ports. It tries to match the open firmware
 504  * default output with one of the available serial console drivers, either
 505  * one of the platform serial ports that have been probed earlier by
 506  * find_legacy_serial_ports() or some more platform specific ones.
 507  */
 508 static int __init check_legacy_serial_console(void)
 509 {
 510         struct device_node *prom_stdout = NULL;
 511         int speed = 0, offset = 0;
 512         const char *name;
 513         const u32 *spd;
 514
 515         DBG(" -> check_legacy_serial_console()\n");
 516
 517         /* The user has requested a console so this is already set up. */
 518         if (strstr(boot_command_line, "console=")) {
 519                 DBG(" console was specified !\n");
 520                 return -EBUSY;
 521         }
 522
 523         if (!of_chosen) {
 524                 DBG(" of_chosen is NULL !\n");
 525                 return -ENODEV;
 526         }
 527
 528         if (legacy_serial_console < 0) {
 529                 DBG(" legacy_serial_console not found !\n");
 530                 return -ENODEV;
 531         }
 532         /* We are getting a weird phandle from OF ... */
 533         /* ... So use the full path instead */
 534         name = of_get_property(of_chosen, "linux,stdout-path", NULL);
 535         if (name == NULL) {
 536                 DBG(" no linux,stdout-path !\n");
 537                 return -ENODEV;
 538         }
 539         prom_stdout = of_find_node_by_path(name);
 540         if (!prom_stdout) {
 541                 DBG(" can't find stdout package %s !\n", name);
 542                 return -ENODEV;
 543         }
 544         DBG("stdout is %s\n", prom_stdout->full_name);
 545
 546         name = of_get_property(prom_stdout, "name", NULL);
 547         if (!name) {
 548                 DBG(" stdout package has no name !\n");
 549                 goto not_found;
 550         }
 551         spd = of_get_property(prom_stdout, "current-speed", NULL);
 552         if (spd)
 553                 speed = *spd;
 554
 555         if (0)
 556                 ;
 557 #ifdef CONFIG_SERIAL_8250_CONSOLE
 558         else if (strcmp(name, "serial") == 0) {
 559                 int i;
 560                 /* Look for it in probed array */
 561                 for (i = 0; i < legacy_serial_count; i++) {
 562                         if (prom_stdout != legacy_serial_infos[i].np)
 563                                 continue;
 564                         offset = i;
 565                         speed = legacy_serial_infos[i].speed;
 566                         break;
 567                 }
 568                 if (i >= legacy_serial_count)
 569                         goto not_found;
 570         }
 571 #endif /* CONFIG_SERIAL_8250_CONSOLE */
 572 #ifdef CONFIG_SERIAL_PMACZILOG_CONSOLE
 573         else if (strcmp(name, "ch-a") == 0)
 574                 offset = 0;
 575         else if (strcmp(name, "ch-b") == 0)
 576                 offset = 1;
 577 #endif /* CONFIG_SERIAL_PMACZILOG_CONSOLE */
 578         else
 579                 goto not_found;
 580         of_node_put(prom_stdout);
 581
 582         DBG("Found serial console at ttyS%d\n", offset);
 583
 584         if (speed) {
 585                 static char __initdata opt[16];
 586                 sprintf(opt, "%d", speed);
 587                 return add_preferred_console("ttyS", offset, opt);
 588         } else
 589                 return add_preferred_console("ttyS", offset, NULL);
 590
 591  not_found:
 592         DBG("No preferred console found !\n");
 593         of_node_put(prom_stdout);
 594         return -ENODEV;
 595 }
 596 console_initcall(check_legacy_serial_console);
 597