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.h> 9#include <linux/of_address.h> 10#include <linux/of_irq.h> 11#include <linux/serial_reg.h> 12#include <asm/io.h> 13#include <asm/mmu.h> 14#include <asm/serial.h> 15#include <asm/udbg.h> 16#include <asm/pci-bridge.h> 17#include <asm/ppc-pci.h> 18#include <asm/early_ioremap.h> 19 20#undef DEBUG 21 22#ifdef DEBUG 23#define DBG(fmt...) do { printk(fmt); } while(0) 24#else 25#define DBG(fmt...) do { } while(0) 26#endif 27 28#define MAX_LEGACY_SERIAL_PORTS 8 29 30static struct plat_serial8250_port 31legacy_serial_ports[MAX_LEGACY_SERIAL_PORTS+1]; 32static struct legacy_serial_info { 33 struct device_node *np; 34 unsigned int speed; 35 unsigned int clock; 36 int irq_check_parent; 37 phys_addr_t taddr; 38 void __iomem *early_addr; 39} legacy_serial_infos[MAX_LEGACY_SERIAL_PORTS]; 40 41static const struct of_device_id legacy_serial_parents[] __initconst = { 42 {.type = "soc",}, 43 {.type = "tsi-bridge",}, 44 {.type = "opb", }, 45 {.compatible = "ibm,opb",}, 46 {.compatible = "simple-bus",}, 47 {.compatible = "wrs,epld-localbus",}, 48 {}, 49}; 50 51static unsigned int legacy_serial_count; 52static int legacy_serial_console = -1; 53 54static const upf_t legacy_port_flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST | 55 UPF_SHARE_IRQ | UPF_FIXED_PORT; 56 57static unsigned int tsi_serial_in(struct uart_port *p, int offset) 58{ 59 unsigned int tmp; 60 offset = offset << p->regshift; 61 if (offset == UART_IIR) { 62 tmp = readl(p->membase + (UART_IIR & ~3)); 63 return (tmp >> 16) & 0xff; /* UART_IIR % 4 == 2 */ 64 } else 65 return readb(p->membase + offset); 66} 67 68static void tsi_serial_out(struct uart_port *p, int offset, int value) 69{ 70 offset = offset << p->regshift; 71 if (!((offset == UART_IER) && (value & UART_IER_UUE))) 72 writeb(value, p->membase + offset); 73} 74 75static int __init add_legacy_port(struct device_node *np, int want_index, 76 int iotype, phys_addr_t base, 77 phys_addr_t taddr, unsigned long irq, 78 upf_t flags, int irq_check_parent) 79{ 80 const __be32 *clk, *spd, *rs; 81 u32 clock = BASE_BAUD * 16; 82 u32 shift = 0; 83 int index; 84 85 /* get clock freq. if present */ 86 clk = of_get_property(np, "clock-frequency", NULL); 87 if (clk && *clk) 88 clock = be32_to_cpup(clk); 89 90 /* get default speed if present */ 91 spd = of_get_property(np, "current-speed", NULL); 92 93 /* get register shift if present */ 94 rs = of_get_property(np, "reg-shift", NULL); 95 if (rs && *rs) 96 shift = be32_to_cpup(rs); 97 98 /* If we have a location index, then try to use it */ 99 if (want_index >= 0 && want_index < MAX_LEGACY_SERIAL_PORTS) 100 index = want_index; 101 else 102 index = legacy_serial_count; 103 104 /* if our index is still out of range, that mean that 105 * array is full, we could scan for a free slot but that 106 * make little sense to bother, just skip the port 107 */ 108 if (index >= MAX_LEGACY_SERIAL_PORTS) 109 return -1; 110 if (index >= legacy_serial_count) 111 legacy_serial_count = index + 1; 112 113 /* Check if there is a port who already claimed our slot */ 114 if (legacy_serial_infos[index].np != NULL) { 115 /* if we still have some room, move it, else override */ 116 if (legacy_serial_count < MAX_LEGACY_SERIAL_PORTS) { 117 printk(KERN_DEBUG "Moved legacy port %d -> %d\n", 118 index, legacy_serial_count); 119 legacy_serial_ports[legacy_serial_count] = 120 legacy_serial_ports[index]; 121 legacy_serial_infos[legacy_serial_count] = 122 legacy_serial_infos[index]; 123 legacy_serial_count++; 124 } else { 125 printk(KERN_DEBUG "Replacing legacy port %d\n", index); 126 } 127 } 128 129 /* Now fill the entry */ 130 memset(&legacy_serial_ports[index], 0, 131 sizeof(struct plat_serial8250_port)); 132 if (iotype == UPIO_PORT) 133 legacy_serial_ports[index].iobase = base; 134 else 135 legacy_serial_ports[index].mapbase = base; 136 137 legacy_serial_ports[index].iotype = iotype; 138 legacy_serial_ports[index].uartclk = clock; 139 legacy_serial_ports[index].irq = irq; 140 legacy_serial_ports[index].flags = flags; 141 legacy_serial_ports[index].regshift = shift; 142 legacy_serial_infos[index].taddr = taddr; 143 legacy_serial_infos[index].np = of_node_get(np); 144 legacy_serial_infos[index].clock = clock; 145 legacy_serial_infos[index].speed = spd ? be32_to_cpup(spd) : 0; 146 legacy_serial_infos[index].irq_check_parent = irq_check_parent; 147 148 if (iotype == UPIO_TSI) { 149 legacy_serial_ports[index].serial_in = tsi_serial_in; 150 legacy_serial_ports[index].serial_out = tsi_serial_out; 151 } 152 153 printk(KERN_DEBUG "Found legacy serial port %d for %pOF\n", 154 index, np); 155 printk(KERN_DEBUG " %s=%llx, taddr=%llx, irq=%lx, clk=%d, speed=%d\n", 156 (iotype == UPIO_PORT) ? "port" : "mem", 157 (unsigned long long)base, (unsigned long long)taddr, irq, 158 legacy_serial_ports[index].uartclk, 159 legacy_serial_infos[index].speed); 160 161 return index; 162} 163 164static int __init add_legacy_soc_port(struct device_node *np, 165 struct device_node *soc_dev) 166{ 167 u64 addr; 168 const __be32 *addrp; 169 struct device_node *tsi = of_get_parent(np); 170 171 /* We only support ports that have a clock frequency properly 172 * encoded in the device-tree. 173 */ 174 if (!of_property_present(np, "clock-frequency")) 175 return -1; 176 177 /* if reg-offset don't try to use it */ 178 if (of_property_present(np, "reg-offset")) 179 return -1; 180 181 /* if rtas uses this device, don't try to use it as well */ 182 if (of_property_read_bool(np, "used-by-rtas")) 183 return -1; 184 185 /* Get the address */ 186 addrp = of_get_address(soc_dev, 0, NULL, NULL); 187 if (addrp == NULL) 188 return -1; 189 190 addr = of_translate_address(soc_dev, addrp); 191 if (addr == OF_BAD_ADDR) 192 return -1; 193 194 /* Add port, irq will be dealt with later. We passed a translated 195 * IO port value. It will be fixed up later along with the irq 196 */ 197 if (of_node_is_type(tsi, "tsi-bridge")) 198 return add_legacy_port(np, -1, UPIO_TSI, addr, addr, 199 0, legacy_port_flags, 0); 200 else 201 return add_legacy_port(np, -1, UPIO_MEM, addr, addr, 202 0, legacy_port_flags, 0); 203} 204 205static int __init add_legacy_isa_port(struct device_node *np, 206 struct device_node *isa_brg) 207{ 208 const __be32 *reg; 209 const char *typep; 210 int index = -1; 211 u64 taddr; 212 213 DBG(" -> add_legacy_isa_port(%pOF)\n", np); 214 215 /* Get the ISA port number */ 216 reg = of_get_property(np, "reg", NULL); 217 if (reg == NULL) 218 return -1; 219 220 /* Verify it's an IO port, we don't support anything else */ 221 if (!(be32_to_cpu(reg[0]) & 0x00000001)) 222 return -1; 223 224 /* Now look for an "ibm,aix-loc" property that gives us ordering 225 * if any... 226 */ 227 typep = of_get_property(np, "ibm,aix-loc", NULL); 228 229 /* If we have a location index, then use it */ 230 if (typep && *typep == 'S') 231 index = simple_strtol(typep+1, NULL, 0) - 1; 232 233 /* Translate ISA address. If it fails, we still register the port 234 * with no translated address so that it can be picked up as an IO 235 * port later by the serial driver 236 * 237 * Note: Don't even try on P8 lpc, we know it's not directly mapped 238 */ 239 if (!of_device_is_compatible(isa_brg, "ibm,power8-lpc") || 240 of_property_present(isa_brg, "ranges")) { 241 taddr = of_translate_address(np, reg); 242 if (taddr == OF_BAD_ADDR) 243 taddr = 0; 244 } else 245 taddr = 0; 246 247 /* Add port, irq will be dealt with later */ 248 return add_legacy_port(np, index, UPIO_PORT, be32_to_cpu(reg[1]), 249 taddr, 0, legacy_port_flags, 0); 250 251} 252 253#ifdef CONFIG_PCI 254static int __init add_legacy_pci_port(struct device_node *np, 255 struct device_node *pci_dev) 256{ 257 u64 addr, base; 258 const __be32 *addrp; 259 unsigned int flags; 260 int iotype, index = -1, lindex = 0; 261 262 DBG(" -> add_legacy_pci_port(%pOF)\n", np); 263 264 /* We only support ports that have a clock frequency properly 265 * encoded in the device-tree (that is have an fcode). Anything 266 * else can't be used that early and will be normally probed by 267 * the generic 8250_pci driver later on. The reason is that 8250 268 * compatible UARTs on PCI need all sort of quirks (port offsets 269 * etc...) that this code doesn't know about 270 */ 271 if (!of_property_present(np, "clock-frequency")) 272 return -1; 273 274 /* Get the PCI address. Assume BAR 0 */ 275 addrp = of_get_pci_address(pci_dev, 0, NULL, &flags); 276 if (addrp == NULL) 277 return -1; 278 279 /* We only support BAR 0 for now */ 280 iotype = (flags & IORESOURCE_MEM) ? UPIO_MEM : UPIO_PORT; 281 addr = of_translate_address(pci_dev, addrp); 282 if (addr == OF_BAD_ADDR) 283 return -1; 284 285 /* Set the IO base to the same as the translated address for MMIO, 286 * or to the domain local IO base for PIO (it will be fixed up later) 287 */ 288 if (iotype == UPIO_MEM) 289 base = addr; 290 else 291 base = of_read_number(&addrp[2], 1); 292 293 /* Try to guess an index... If we have subdevices of the pci dev, 294 * we get to their "reg" property 295 */ 296 if (np != pci_dev) { 297 const __be32 *reg = of_get_property(np, "reg", NULL); 298 if (reg && (be32_to_cpup(reg) < 4)) 299 index = lindex = be32_to_cpup(reg); 300 } 301 302 /* Local index means it's the Nth port in the PCI chip. Unfortunately 303 * the offset to add here is device specific. We know about those 304 * EXAR ports and we default to the most common case. If your UART 305 * doesn't work for these settings, you'll have to add your own special 306 * cases here 307 */ 308 if (of_device_is_compatible(pci_dev, "pci13a8,152") || 309 of_device_is_compatible(pci_dev, "pci13a8,154") || 310 of_device_is_compatible(pci_dev, "pci13a8,158")) { 311 addr += 0x200 * lindex; 312 base += 0x200 * lindex; 313 } else { 314 addr += 8 * lindex; 315 base += 8 * lindex; 316 } 317 318 /* Add port, irq will be dealt with later. We passed a translated 319 * IO port value. It will be fixed up later along with the irq 320 */ 321 return add_legacy_port(np, index, iotype, base, addr, 0, 322 legacy_port_flags, np != pci_dev); 323} 324#endif 325 326static void __init setup_legacy_serial_console(int console) 327{ 328 struct legacy_serial_info *info = &legacy_serial_infos[console]; 329 struct plat_serial8250_port *port = &legacy_serial_ports[console]; 330 unsigned int stride; 331 332 stride = 1 << port->regshift; 333 334 /* Check if a translated MMIO address has been found */ 335 if (info->taddr) { 336 info->early_addr = early_ioremap(info->taddr, 0x1000); 337 if (info->early_addr == NULL) 338 return; 339 udbg_uart_init_mmio(info->early_addr, stride); 340 } else { 341 /* Check if it's PIO and we support untranslated PIO */ 342 if (port->iotype == UPIO_PORT && isa_io_special) 343 udbg_uart_init_pio(port->iobase, stride); 344 else 345 return; 346 } 347 348 /* Try to query the current speed */ 349 if (info->speed == 0) 350 info->speed = udbg_probe_uart_speed(info->clock); 351 352 /* Set it up */ 353 DBG("default console speed = %d\n", info->speed); 354 udbg_uart_setup(info->speed, info->clock); 355} 356 357static int __init ioremap_legacy_serial_console(void) 358{ 359 struct plat_serial8250_port *port; 360 struct legacy_serial_info *info; 361 void __iomem *vaddr; 362 363 if (legacy_serial_console < 0) 364 return 0; 365 366 info = &legacy_serial_infos[legacy_serial_console]; 367 port = &legacy_serial_ports[legacy_serial_console]; 368 369 if (!info->early_addr) 370 return 0; 371 372 vaddr = ioremap(info->taddr, 0x1000); 373 if (WARN_ON(!vaddr)) 374 return -ENOMEM; 375 376 udbg_uart_init_mmio(vaddr, 1 << port->regshift); 377 early_iounmap(info->early_addr, 0x1000); 378 info->early_addr = NULL; 379 380 return 0; 381} 382early_initcall(ioremap_legacy_serial_console); 383 384/* 385 * This is called very early, as part of setup_system() or eventually 386 * setup_arch(), basically before anything else in this file. This function 387 * will try to build a list of all the available 8250-compatible serial ports 388 * in the machine using the Open Firmware device-tree. It currently only deals 389 * with ISA and PCI busses but could be extended. It allows a very early boot 390 * console to be initialized, that list is also used later to provide 8250 with 391 * the machine non-PCI ports and to properly pick the default console port 392 */ 393void __init find_legacy_serial_ports(void) 394{ 395 struct device_node *np, *stdout = NULL; 396 const char *path; 397 int index; 398 399 DBG(" -> find_legacy_serial_port()\n"); 400 401 /* Now find out if one of these is out firmware console */ 402 path = of_get_property(of_chosen, "linux,stdout-path", NULL); 403 if (path == NULL) 404 path = of_get_property(of_chosen, "stdout-path", NULL); 405 if (path != NULL) { 406 stdout = of_find_node_by_path(path); 407 if (stdout) 408 DBG("stdout is %pOF\n", stdout); 409 } else { 410 DBG(" no linux,stdout-path !\n"); 411 } 412 413 /* Iterate over all the 16550 ports, looking for known parents */ 414 for_each_compatible_node(np, "serial", "ns16550") { 415 struct device_node *parent = of_get_parent(np); 416 if (!parent) 417 continue; 418 if (of_match_node(legacy_serial_parents, parent) != NULL) { 419 if (of_device_is_available(np)) { 420 index = add_legacy_soc_port(np, np); 421 if (index >= 0 && np == stdout) 422 legacy_serial_console = index; 423 } 424 } 425 of_node_put(parent); 426 } 427 428 /* Next, fill our array with ISA ports */ 429 for_each_node_by_type(np, "serial") { 430 struct device_node *isa = of_get_parent(np); 431 if (of_node_name_eq(isa, "isa") || of_node_name_eq(isa, "lpc")) { 432 if (of_device_is_available(np)) { 433 index = add_legacy_isa_port(np, isa); 434 if (index >= 0 && np == stdout) 435 legacy_serial_console = index; 436 } 437 } 438 of_node_put(isa); 439 } 440 441#ifdef CONFIG_PCI 442 /* Next, try to locate PCI ports */ 443 for (np = NULL; (np = of_find_all_nodes(np));) { 444 struct device_node *pci, *parent = of_get_parent(np); 445 if (of_node_name_eq(parent, "isa")) { 446 of_node_put(parent); 447 continue; 448 } 449 if (!of_node_name_eq(np, "serial") && 450 !of_node_is_type(np, "serial")) { 451 of_node_put(parent); 452 continue; 453 } 454 /* Check for known pciclass, and also check whether we have 455 * a device with child nodes for ports or not 456 */ 457 if (of_device_is_compatible(np, "pciclass,0700") || 458 of_device_is_compatible(np, "pciclass,070002")) 459 pci = np; 460 else if (of_device_is_compatible(parent, "pciclass,0700") || 461 of_device_is_compatible(parent, "pciclass,070002")) 462 pci = parent; 463 else { 464 of_node_put(parent); 465 continue; 466 } 467 index = add_legacy_pci_port(np, pci); 468 if (index >= 0 && np == stdout) 469 legacy_serial_console = index; 470 of_node_put(parent); 471 } 472#endif 473 474 of_node_put(stdout); 475 476 DBG("legacy_serial_console = %d\n", legacy_serial_console); 477 if (legacy_serial_console >= 0) 478 setup_legacy_serial_console(legacy_serial_console); 479 DBG(" <- find_legacy_serial_port()\n"); 480} 481 482static struct platform_device serial_device = { 483 .name = "serial8250", 484 .id = PLAT8250_DEV_PLATFORM, 485 .dev = { 486 .platform_data = legacy_serial_ports, 487 }, 488}; 489 490static void __init fixup_port_irq(int index, 491 struct device_node *np, 492 struct plat_serial8250_port *port) 493{ 494 unsigned int virq; 495 496 DBG("fixup_port_irq(%d)\n", index); 497 498 virq = irq_of_parse_and_map(np, 0); 499 if (!virq && legacy_serial_infos[index].irq_check_parent) { 500 np = of_get_parent(np); 501 if (np == NULL) 502 return; 503 virq = irq_of_parse_and_map(np, 0); 504 of_node_put(np); 505 } 506 if (!virq) 507 return; 508 509 port->irq = virq; 510 511 if (IS_ENABLED(CONFIG_SERIAL_8250) && 512 of_device_is_compatible(np, "fsl,ns16550")) { 513 if (IS_REACHABLE(CONFIG_SERIAL_8250_FSL)) { 514 port->handle_irq = fsl8250_handle_irq; 515 port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE); 516 } else { 517 pr_warn_once("Not activating Freescale specific workaround for device %pOFP\n", 518 np); 519 } 520 } 521} 522 523static void __init fixup_port_pio(int index, 524 struct device_node *np, 525 struct plat_serial8250_port *port) 526{ 527#ifdef CONFIG_PCI 528 struct pci_controller *hose; 529 530 DBG("fixup_port_pio(%d)\n", index); 531 532 hose = pci_find_hose_for_OF_device(np); 533 if (hose) { 534 unsigned long offset = (unsigned long)hose->io_base_virt - 535#ifdef CONFIG_PPC64 536 pci_io_base; 537#else 538 isa_io_base; 539#endif 540 DBG("port %d, IO %lx -> %lx\n", 541 index, port->iobase, port->iobase + offset); 542 port->iobase += offset; 543 } 544#endif 545} 546 547static void __init fixup_port_mmio(int index, 548 struct device_node *np, 549 struct plat_serial8250_port *port) 550{ 551 DBG("fixup_port_mmio(%d)\n", index); 552 553 port->membase = ioremap(port->mapbase, 0x100); 554} 555 556/* 557 * This is called as an arch initcall, hopefully before the PCI bus is 558 * probed and/or the 8250 driver loaded since we need to register our 559 * platform devices before 8250 PCI ones are detected as some of them 560 * must properly "override" the platform ones. 561 * 562 * This function fixes up the interrupt value for platform ports as it 563 * couldn't be done earlier before interrupt maps have been parsed. It 564 * also "corrects" the IO address for PIO ports for the same reason, 565 * since earlier, the PHBs virtual IO space wasn't assigned yet. It then 566 * registers all those platform ports for use by the 8250 driver when it 567 * finally loads. 568 */ 569static int __init serial_dev_init(void) 570{ 571 int i; 572 573 if (legacy_serial_count == 0) 574 return -ENODEV; 575 576 /* 577 * Before we register the platform serial devices, we need 578 * to fixup their interrupts and their IO ports. 579 */ 580 DBG("Fixing serial ports interrupts and IO ports ...\n"); 581 582 for (i = 0; i < legacy_serial_count; i++) { 583 struct plat_serial8250_port *port = &legacy_serial_ports[i]; 584 struct device_node *np = legacy_serial_infos[i].np; 585 586 if (!port->irq) 587 fixup_port_irq(i, np, port); 588 if (port->iotype == UPIO_PORT) 589 fixup_port_pio(i, np, port); 590 if ((port->iotype == UPIO_MEM) || (port->iotype == UPIO_TSI)) 591 fixup_port_mmio(i, np, port); 592 } 593 594 DBG("Registering platform serial ports\n"); 595 596 return platform_device_register(&serial_device); 597} 598device_initcall(serial_dev_init); 599 600 601#ifdef CONFIG_SERIAL_8250_CONSOLE 602/* 603 * This is called very early, as part of console_init() (typically just after 604 * time_init()). This function is respondible for trying to find a good 605 * default console on serial ports. It tries to match the open firmware 606 * default output with one of the available serial console drivers that have 607 * been probed earlier by find_legacy_serial_ports() 608 */ 609static int __init check_legacy_serial_console(void) 610{ 611 struct device_node *prom_stdout = NULL; 612 int i, speed = 0, offset = 0; 613 const char *name; 614 const __be32 *spd; 615 616 DBG(" -> check_legacy_serial_console()\n"); 617 618 /* The user has requested a console so this is already set up. */ 619 if (strstr(boot_command_line, "console=")) { 620 DBG(" console was specified !\n"); 621 return -EBUSY; 622 } 623 624 if (!of_chosen) { 625 DBG(" of_chosen is NULL !\n"); 626 return -ENODEV; 627 } 628 629 if (legacy_serial_console < 0) { 630 DBG(" legacy_serial_console not found !\n"); 631 return -ENODEV; 632 } 633 /* We are getting a weird phandle from OF ... */ 634 /* ... So use the full path instead */ 635 name = of_get_property(of_chosen, "linux,stdout-path", NULL); 636 if (name == NULL) 637 name = of_get_property(of_chosen, "stdout-path", NULL); 638 if (name == NULL) { 639 DBG(" no stdout-path !\n"); 640 return -ENODEV; 641 } 642 prom_stdout = of_find_node_by_path(name); 643 if (!prom_stdout) { 644 DBG(" can't find stdout package %s !\n", name); 645 return -ENODEV; 646 } 647 DBG("stdout is %pOF\n", prom_stdout); 648 649 name = of_get_property(prom_stdout, "name", NULL); 650 if (!name) { 651 DBG(" stdout package has no name !\n"); 652 goto not_found; 653 } 654 spd = of_get_property(prom_stdout, "current-speed", NULL); 655 if (spd) 656 speed = be32_to_cpup(spd); 657 658 if (strcmp(name, "serial") != 0) 659 goto not_found; 660 661 /* Look for it in probed array */ 662 for (i = 0; i < legacy_serial_count; i++) { 663 if (prom_stdout != legacy_serial_infos[i].np) 664 continue; 665 offset = i; 666 speed = legacy_serial_infos[i].speed; 667 break; 668 } 669 if (i >= legacy_serial_count) 670 goto not_found; 671 672 of_node_put(prom_stdout); 673 674 DBG("Found serial console at ttyS%d\n", offset); 675 676 if (speed) { 677 static char __initdata opt[16]; 678 sprintf(opt, "%d", speed); 679 return add_preferred_console("ttyS", offset, opt); 680 } else 681 return add_preferred_console("ttyS", offset, NULL); 682 683 not_found: 684 DBG("No preferred console found !\n"); 685 of_node_put(prom_stdout); 686 return -ENODEV; 687} 688console_initcall(check_legacy_serial_console); 689 690#endif /* CONFIG_SERIAL_8250_CONSOLE */ 691