1 // SPDX-License-Identifier: GPL-2.0 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 <linux/of_address.h> 9 #include <linux/of_device.h> 10 #include <linux/serial_reg.h> 11 #include <asm/io.h> 12 #include <asm/mmu.h> 13 #include <asm/prom.h> 14 #include <asm/serial.h> 15 #include <asm/udbg.h> 16 #include <asm/pci-bridge.h> 17 #include <asm/ppc-pci.h> 18 19 #undef DEBUG 20 21 #ifdef DEBUG 22 #define DBG(fmt...) do { printk(fmt); } while(0) 23 #else 24 #define DBG(fmt...) do { } while(0) 25 #endif 26 27 #define MAX_LEGACY_SERIAL_PORTS 8 28 29 static struct plat_serial8250_port 30 legacy_serial_ports[MAX_LEGACY_SERIAL_PORTS+1]; 31 static struct legacy_serial_info { 32 struct device_node *np; 33 unsigned int speed; 34 unsigned int clock; 35 int irq_check_parent; 36 phys_addr_t taddr; 37 } legacy_serial_infos[MAX_LEGACY_SERIAL_PORTS]; 38 39 static const struct of_device_id legacy_serial_parents[] __initconst = { 40 {.type = "soc",}, 41 {.type = "tsi-bridge",}, 42 {.type = "opb", }, 43 {.compatible = "ibm,opb",}, 44 {.compatible = "simple-bus",}, 45 {.compatible = "wrs,epld-localbus",}, 46 {}, 47 }; 48 49 static unsigned int legacy_serial_count; 50 static int legacy_serial_console = -1; 51 52 static const upf_t legacy_port_flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST | 53 UPF_SHARE_IRQ | UPF_FIXED_PORT; 54 55 static unsigned int tsi_serial_in(struct uart_port *p, int offset) 56 { 57 unsigned int tmp; 58 offset = offset << p->regshift; 59 if (offset == UART_IIR) { 60 tmp = readl(p->membase + (UART_IIR & ~3)); 61 return (tmp >> 16) & 0xff; /* UART_IIR % 4 == 2 */ 62 } else 63 return readb(p->membase + offset); 64 } 65 66 static void tsi_serial_out(struct uart_port *p, int offset, int value) 67 { 68 offset = offset << p->regshift; 69 if (!((offset == UART_IER) && (value & UART_IER_UUE))) 70 writeb(value, p->membase + offset); 71 } 72 73 static int __init add_legacy_port(struct device_node *np, int want_index, 74 int iotype, phys_addr_t base, 75 phys_addr_t taddr, unsigned long irq, 76 upf_t flags, int irq_check_parent) 77 { 78 const __be32 *clk, *spd, *rs; 79 u32 clock = BASE_BAUD * 16; 80 u32 shift = 0; 81 int index; 82 83 /* get clock freq. if present */ 84 clk = of_get_property(np, "clock-frequency", NULL); 85 if (clk && *clk) 86 clock = be32_to_cpup(clk); 87 88 /* get default speed if present */ 89 spd = of_get_property(np, "current-speed", NULL); 90 91 /* get register shift if present */ 92 rs = of_get_property(np, "reg-shift", NULL); 93 if (rs && *rs) 94 shift = be32_to_cpup(rs); 95 96 /* If we have a location index, then try to use it */ 97 if (want_index >= 0 && want_index < MAX_LEGACY_SERIAL_PORTS) 98 index = want_index; 99 else 100 index = legacy_serial_count; 101 102 /* if our index is still out of range, that mean that 103 * array is full, we could scan for a free slot but that 104 * make little sense to bother, just skip the port 105 */ 106 if (index >= MAX_LEGACY_SERIAL_PORTS) 107 return -1; 108 if (index >= legacy_serial_count) 109 legacy_serial_count = index + 1; 110 111 /* Check if there is a port who already claimed our slot */ 112 if (legacy_serial_infos[index].np != NULL) { 113 /* if we still have some room, move it, else override */ 114 if (legacy_serial_count < MAX_LEGACY_SERIAL_PORTS) { 115 printk(KERN_DEBUG "Moved legacy port %d -> %d\n", 116 index, legacy_serial_count); 117 legacy_serial_ports[legacy_serial_count] = 118 legacy_serial_ports[index]; 119 legacy_serial_infos[legacy_serial_count] = 120 legacy_serial_infos[index]; 121 legacy_serial_count++; 122 } else { 123 printk(KERN_DEBUG "Replacing legacy port %d\n", index); 124 } 125 } 126 127 /* Now fill the entry */ 128 memset(&legacy_serial_ports[index], 0, 129 sizeof(struct plat_serial8250_port)); 130 if (iotype == UPIO_PORT) 131 legacy_serial_ports[index].iobase = base; 132 else 133 legacy_serial_ports[index].mapbase = base; 134 135 legacy_serial_ports[index].iotype = iotype; 136 legacy_serial_ports[index].uartclk = clock; 137 legacy_serial_ports[index].irq = irq; 138 legacy_serial_ports[index].flags = flags; 139 legacy_serial_ports[index].regshift = shift; 140 legacy_serial_infos[index].taddr = taddr; 141 legacy_serial_infos[index].np = of_node_get(np); 142 legacy_serial_infos[index].clock = clock; 143 legacy_serial_infos[index].speed = spd ? be32_to_cpup(spd) : 0; 144 legacy_serial_infos[index].irq_check_parent = irq_check_parent; 145 146 if (iotype == UPIO_TSI) { 147 legacy_serial_ports[index].serial_in = tsi_serial_in; 148 legacy_serial_ports[index].serial_out = tsi_serial_out; 149 } 150 151 printk(KERN_DEBUG "Found legacy serial port %d for %pOF\n", 152 index, np); 153 printk(KERN_DEBUG " %s=%llx, taddr=%llx, irq=%lx, clk=%d, speed=%d\n", 154 (iotype == UPIO_PORT) ? "port" : "mem", 155 (unsigned long long)base, (unsigned long long)taddr, irq, 156 legacy_serial_ports[index].uartclk, 157 legacy_serial_infos[index].speed); 158 159 return index; 160 } 161 162 static int __init add_legacy_soc_port(struct device_node *np, 163 struct device_node *soc_dev) 164 { 165 u64 addr; 166 const __be32 *addrp; 167 struct device_node *tsi = of_get_parent(np); 168 169 /* We only support ports that have a clock frequency properly 170 * encoded in the device-tree. 171 */ 172 if (of_get_property(np, "clock-frequency", NULL) == NULL) 173 return -1; 174 175 /* if reg-offset don't try to use it */ 176 if ((of_get_property(np, "reg-offset", NULL) != NULL)) 177 return -1; 178 179 /* if rtas uses this device, don't try to use it as well */ 180 if (of_get_property(np, "used-by-rtas", NULL) != NULL) 181 return -1; 182 183 /* Get the address */ 184 addrp = of_get_address(soc_dev, 0, NULL, NULL); 185 if (addrp == NULL) 186 return -1; 187 188 addr = of_translate_address(soc_dev, addrp); 189 if (addr == OF_BAD_ADDR) 190 return -1; 191 192 /* Add port, irq will be dealt with later. We passed a translated 193 * IO port value. It will be fixed up later along with the irq 194 */ 195 if (tsi && !strcmp(tsi->type, "tsi-bridge")) 196 return add_legacy_port(np, -1, UPIO_TSI, addr, addr, 197 0, legacy_port_flags, 0); 198 else 199 return add_legacy_port(np, -1, UPIO_MEM, addr, addr, 200 0, legacy_port_flags, 0); 201 } 202 203 static int __init add_legacy_isa_port(struct device_node *np, 204 struct device_node *isa_brg) 205 { 206 const __be32 *reg; 207 const char *typep; 208 int index = -1; 209 u64 taddr; 210 211 DBG(" -> add_legacy_isa_port(%pOF)\n", np); 212 213 /* Get the ISA port number */ 214 reg = of_get_property(np, "reg", NULL); 215 if (reg == NULL) 216 return -1; 217 218 /* Verify it's an IO port, we don't support anything else */ 219 if (!(be32_to_cpu(reg[0]) & 0x00000001)) 220 return -1; 221 222 /* Now look for an "ibm,aix-loc" property that gives us ordering 223 * if any... 224 */ 225 typep = of_get_property(np, "ibm,aix-loc", NULL); 226 227 /* If we have a location index, then use it */ 228 if (typep && *typep == 'S') 229 index = simple_strtol(typep+1, NULL, 0) - 1; 230 231 /* Translate ISA address. If it fails, we still register the port 232 * with no translated address so that it can be picked up as an IO 233 * port later by the serial driver 234 * 235 * Note: Don't even try on P8 lpc, we know it's not directly mapped 236 */ 237 if (!of_device_is_compatible(isa_brg, "ibm,power8-lpc") || 238 of_get_property(isa_brg, "ranges", NULL)) { 239 taddr = of_translate_address(np, reg); 240 if (taddr == OF_BAD_ADDR) 241 taddr = 0; 242 } else 243 taddr = 0; 244 245 /* Add port, irq will be dealt with later */ 246 return add_legacy_port(np, index, UPIO_PORT, be32_to_cpu(reg[1]), 247 taddr, 0, legacy_port_flags, 0); 248 249 } 250 251 #ifdef CONFIG_PCI 252 static int __init add_legacy_pci_port(struct device_node *np, 253 struct device_node *pci_dev) 254 { 255 u64 addr, base; 256 const __be32 *addrp; 257 unsigned int flags; 258 int iotype, index = -1, lindex = 0; 259 260 DBG(" -> add_legacy_pci_port(%pOF)\n", np); 261 262 /* We only support ports that have a clock frequency properly 263 * encoded in the device-tree (that is have an fcode). Anything 264 * else can't be used that early and will be normally probed by 265 * the generic 8250_pci driver later on. The reason is that 8250 266 * compatible UARTs on PCI need all sort of quirks (port offsets 267 * etc...) that this code doesn't know about 268 */ 269 if (of_get_property(np, "clock-frequency", NULL) == NULL) 270 return -1; 271 272 /* Get the PCI address. Assume BAR 0 */ 273 addrp = of_get_pci_address(pci_dev, 0, NULL, &flags); 274 if (addrp == NULL) 275 return -1; 276 277 /* We only support BAR 0 for now */ 278 iotype = (flags & IORESOURCE_MEM) ? UPIO_MEM : UPIO_PORT; 279 addr = of_translate_address(pci_dev, addrp); 280 if (addr == OF_BAD_ADDR) 281 return -1; 282 283 /* Set the IO base to the same as the translated address for MMIO, 284 * or to the domain local IO base for PIO (it will be fixed up later) 285 */ 286 if (iotype == UPIO_MEM) 287 base = addr; 288 else 289 base = of_read_number(&addrp[2], 1); 290 291 /* Try to guess an index... If we have subdevices of the pci dev, 292 * we get to their "reg" property 293 */ 294 if (np != pci_dev) { 295 const __be32 *reg = of_get_property(np, "reg", NULL); 296 if (reg && (be32_to_cpup(reg) < 4)) 297 index = lindex = be32_to_cpup(reg); 298 } 299 300 /* Local index means it's the Nth port in the PCI chip. Unfortunately 301 * the offset to add here is device specific. We know about those 302 * EXAR ports and we default to the most common case. If your UART 303 * doesn't work for these settings, you'll have to add your own special 304 * cases here 305 */ 306 if (of_device_is_compatible(pci_dev, "pci13a8,152") || 307 of_device_is_compatible(pci_dev, "pci13a8,154") || 308 of_device_is_compatible(pci_dev, "pci13a8,158")) { 309 addr += 0x200 * lindex; 310 base += 0x200 * lindex; 311 } else { 312 addr += 8 * lindex; 313 base += 8 * lindex; 314 } 315 316 /* Add port, irq will be dealt with later. We passed a translated 317 * IO port value. It will be fixed up later along with the irq 318 */ 319 return add_legacy_port(np, index, iotype, base, addr, 0, 320 legacy_port_flags, np != pci_dev); 321 } 322 #endif 323 324 static void __init setup_legacy_serial_console(int console) 325 { 326 struct legacy_serial_info *info = &legacy_serial_infos[console]; 327 struct plat_serial8250_port *port = &legacy_serial_ports[console]; 328 void __iomem *addr; 329 unsigned int stride; 330 331 stride = 1 << port->regshift; 332 333 /* Check if a translated MMIO address has been found */ 334 if (info->taddr) { 335 addr = ioremap(info->taddr, 0x1000); 336 if (addr == NULL) 337 return; 338 udbg_uart_init_mmio(addr, stride); 339 } else { 340 /* Check if it's PIO and we support untranslated PIO */ 341 if (port->iotype == UPIO_PORT && isa_io_special) 342 udbg_uart_init_pio(port->iobase, stride); 343 else 344 return; 345 } 346 347 /* Try to query the current speed */ 348 if (info->speed == 0) 349 info->speed = udbg_probe_uart_speed(info->clock); 350 351 /* Set it up */ 352 DBG("default console speed = %d\n", info->speed); 353 udbg_uart_setup(info->speed, info->clock); 354 } 355 356 /* 357 * This is called very early, as part of setup_system() or eventually 358 * setup_arch(), basically before anything else in this file. This function 359 * will try to build a list of all the available 8250-compatible serial ports 360 * in the machine using the Open Firmware device-tree. It currently only deals 361 * with ISA and PCI busses but could be extended. It allows a very early boot 362 * console to be initialized, that list is also used later to provide 8250 with 363 * the machine non-PCI ports and to properly pick the default console port 364 */ 365 void __init find_legacy_serial_ports(void) 366 { 367 struct device_node *np, *stdout = NULL; 368 const char *path; 369 int index; 370 371 DBG(" -> find_legacy_serial_port()\n"); 372 373 /* Now find out if one of these is out firmware console */ 374 path = of_get_property(of_chosen, "linux,stdout-path", NULL); 375 if (path != NULL) { 376 stdout = of_find_node_by_path(path); 377 if (stdout) 378 DBG("stdout is %pOF\n", stdout); 379 } else { 380 DBG(" no linux,stdout-path !\n"); 381 } 382 383 /* Iterate over all the 16550 ports, looking for known parents */ 384 for_each_compatible_node(np, "serial", "ns16550") { 385 struct device_node *parent = of_get_parent(np); 386 if (!parent) 387 continue; 388 if (of_match_node(legacy_serial_parents, parent) != NULL) { 389 if (of_device_is_available(np)) { 390 index = add_legacy_soc_port(np, np); 391 if (index >= 0 && np == stdout) 392 legacy_serial_console = index; 393 } 394 } 395 of_node_put(parent); 396 } 397 398 /* Next, fill our array with ISA ports */ 399 for_each_node_by_type(np, "serial") { 400 struct device_node *isa = of_get_parent(np); 401 if (isa && (!strcmp(isa->name, "isa") || 402 !strcmp(isa->name, "lpc"))) { 403 if (of_device_is_available(np)) { 404 index = add_legacy_isa_port(np, isa); 405 if (index >= 0 && np == stdout) 406 legacy_serial_console = index; 407 } 408 } 409 of_node_put(isa); 410 } 411 412 #ifdef CONFIG_PCI 413 /* Next, try to locate PCI ports */ 414 for (np = NULL; (np = of_find_all_nodes(np));) { 415 struct device_node *pci, *parent = of_get_parent(np); 416 if (parent && !strcmp(parent->name, "isa")) { 417 of_node_put(parent); 418 continue; 419 } 420 if (strcmp(np->name, "serial") && strcmp(np->type, "serial")) { 421 of_node_put(parent); 422 continue; 423 } 424 /* Check for known pciclass, and also check whether we have 425 * a device with child nodes for ports or not 426 */ 427 if (of_device_is_compatible(np, "pciclass,0700") || 428 of_device_is_compatible(np, "pciclass,070002")) 429 pci = np; 430 else if (of_device_is_compatible(parent, "pciclass,0700") || 431 of_device_is_compatible(parent, "pciclass,070002")) 432 pci = parent; 433 else { 434 of_node_put(parent); 435 continue; 436 } 437 index = add_legacy_pci_port(np, pci); 438 if (index >= 0 && np == stdout) 439 legacy_serial_console = index; 440 of_node_put(parent); 441 } 442 #endif 443 444 DBG("legacy_serial_console = %d\n", legacy_serial_console); 445 if (legacy_serial_console >= 0) 446 setup_legacy_serial_console(legacy_serial_console); 447 DBG(" <- find_legacy_serial_port()\n"); 448 } 449 450 static struct platform_device serial_device = { 451 .name = "serial8250", 452 .id = PLAT8250_DEV_PLATFORM, 453 .dev = { 454 .platform_data = legacy_serial_ports, 455 }, 456 }; 457 458 static void __init fixup_port_irq(int index, 459 struct device_node *np, 460 struct plat_serial8250_port *port) 461 { 462 unsigned int virq; 463 464 DBG("fixup_port_irq(%d)\n", index); 465 466 virq = irq_of_parse_and_map(np, 0); 467 if (!virq && legacy_serial_infos[index].irq_check_parent) { 468 np = of_get_parent(np); 469 if (np == NULL) 470 return; 471 virq = irq_of_parse_and_map(np, 0); 472 of_node_put(np); 473 } 474 if (!virq) 475 return; 476 477 port->irq = virq; 478 479 #ifdef CONFIG_SERIAL_8250_FSL 480 if (of_device_is_compatible(np, "fsl,ns16550")) 481 port->handle_irq = fsl8250_handle_irq; 482 #endif 483 } 484 485 static void __init fixup_port_pio(int index, 486 struct device_node *np, 487 struct plat_serial8250_port *port) 488 { 489 #ifdef CONFIG_PCI 490 struct pci_controller *hose; 491 492 DBG("fixup_port_pio(%d)\n", index); 493 494 hose = pci_find_hose_for_OF_device(np); 495 if (hose) { 496 unsigned long offset = (unsigned long)hose->io_base_virt - 497 #ifdef CONFIG_PPC64 498 pci_io_base; 499 #else 500 isa_io_base; 501 #endif 502 DBG("port %d, IO %lx -> %lx\n", 503 index, port->iobase, port->iobase + offset); 504 port->iobase += offset; 505 } 506 #endif 507 } 508 509 static void __init fixup_port_mmio(int index, 510 struct device_node *np, 511 struct plat_serial8250_port *port) 512 { 513 DBG("fixup_port_mmio(%d)\n", index); 514 515 port->membase = ioremap(port->mapbase, 0x100); 516 } 517 518 /* 519 * This is called as an arch initcall, hopefully before the PCI bus is 520 * probed and/or the 8250 driver loaded since we need to register our 521 * platform devices before 8250 PCI ones are detected as some of them 522 * must properly "override" the platform ones. 523 * 524 * This function fixes up the interrupt value for platform ports as it 525 * couldn't be done earlier before interrupt maps have been parsed. It 526 * also "corrects" the IO address for PIO ports for the same reason, 527 * since earlier, the PHBs virtual IO space wasn't assigned yet. It then 528 * registers all those platform ports for use by the 8250 driver when it 529 * finally loads. 530 */ 531 static int __init serial_dev_init(void) 532 { 533 int i; 534 535 if (legacy_serial_count == 0) 536 return -ENODEV; 537 538 /* 539 * Before we register the platform serial devices, we need 540 * to fixup their interrupts and their IO ports. 541 */ 542 DBG("Fixing serial ports interrupts and IO ports ...\n"); 543 544 for (i = 0; i < legacy_serial_count; i++) { 545 struct plat_serial8250_port *port = &legacy_serial_ports[i]; 546 struct device_node *np = legacy_serial_infos[i].np; 547 548 if (!port->irq) 549 fixup_port_irq(i, np, port); 550 if (port->iotype == UPIO_PORT) 551 fixup_port_pio(i, np, port); 552 if ((port->iotype == UPIO_MEM) || (port->iotype == UPIO_TSI)) 553 fixup_port_mmio(i, np, port); 554 } 555 556 DBG("Registering platform serial ports\n"); 557 558 return platform_device_register(&serial_device); 559 } 560 device_initcall(serial_dev_init); 561 562 563 #ifdef CONFIG_SERIAL_8250_CONSOLE 564 /* 565 * This is called very early, as part of console_init() (typically just after 566 * time_init()). This function is respondible for trying to find a good 567 * default console on serial ports. It tries to match the open firmware 568 * default output with one of the available serial console drivers that have 569 * been probed earlier by find_legacy_serial_ports() 570 */ 571 static int __init check_legacy_serial_console(void) 572 { 573 struct device_node *prom_stdout = NULL; 574 int i, speed = 0, offset = 0; 575 const char *name; 576 const __be32 *spd; 577 578 DBG(" -> check_legacy_serial_console()\n"); 579 580 /* The user has requested a console so this is already set up. */ 581 if (strstr(boot_command_line, "console=")) { 582 DBG(" console was specified !\n"); 583 return -EBUSY; 584 } 585 586 if (!of_chosen) { 587 DBG(" of_chosen is NULL !\n"); 588 return -ENODEV; 589 } 590 591 if (legacy_serial_console < 0) { 592 DBG(" legacy_serial_console not found !\n"); 593 return -ENODEV; 594 } 595 /* We are getting a weird phandle from OF ... */ 596 /* ... So use the full path instead */ 597 name = of_get_property(of_chosen, "linux,stdout-path", NULL); 598 if (name == NULL) { 599 DBG(" no linux,stdout-path !\n"); 600 return -ENODEV; 601 } 602 prom_stdout = of_find_node_by_path(name); 603 if (!prom_stdout) { 604 DBG(" can't find stdout package %s !\n", name); 605 return -ENODEV; 606 } 607 DBG("stdout is %pOF\n", prom_stdout); 608 609 name = of_get_property(prom_stdout, "name", NULL); 610 if (!name) { 611 DBG(" stdout package has no name !\n"); 612 goto not_found; 613 } 614 spd = of_get_property(prom_stdout, "current-speed", NULL); 615 if (spd) 616 speed = be32_to_cpup(spd); 617 618 if (strcmp(name, "serial") != 0) 619 goto not_found; 620 621 /* Look for it in probed array */ 622 for (i = 0; i < legacy_serial_count; i++) { 623 if (prom_stdout != legacy_serial_infos[i].np) 624 continue; 625 offset = i; 626 speed = legacy_serial_infos[i].speed; 627 break; 628 } 629 if (i >= legacy_serial_count) 630 goto not_found; 631 632 of_node_put(prom_stdout); 633 634 DBG("Found serial console at ttyS%d\n", offset); 635 636 if (speed) { 637 static char __initdata opt[16]; 638 sprintf(opt, "%d", speed); 639 return add_preferred_console("ttyS", offset, opt); 640 } else 641 return add_preferred_console("ttyS", offset, NULL); 642 643 not_found: 644 DBG("No preferred console found !\n"); 645 of_node_put(prom_stdout); 646 return -ENODEV; 647 } 648 console_initcall(check_legacy_serial_console); 649 650 #endif /* CONFIG_SERIAL_8250_CONSOLE */ 651