// SPDX-License-Identifier: GPL-2.0 #include <linux/kernel.h> #include <linux/serial.h> #include <linux/serial_8250.h> #include <linux/serial_core.h> #include <linux/console.h> #include <linux/pci.h> #include <linux/of_address.h> #include <linux/of_device.h> #include <linux/serial_reg.h> #include <asm/io.h> #include <asm/mmu.h> #include <asm/prom.h> #include <asm/serial.h> #include <asm/udbg.h> #include <asm/pci-bridge.h> #include <asm/ppc-pci.h> #include <asm/early_ioremap.h> #undef DEBUG #ifdef DEBUG #define DBG(fmt...) do { printk(fmt); } while(0) #else #define DBG(fmt...) do { } while(0) #endif #define MAX_LEGACY_SERIAL_PORTS 8 static struct plat_serial8250_port legacy_serial_ports[MAX_LEGACY_SERIAL_PORTS+1]; static struct legacy_serial_info { struct device_node *np; unsigned int speed; unsigned int clock; int irq_check_parent; phys_addr_t taddr; void __iomem *early_addr; } legacy_serial_infos[MAX_LEGACY_SERIAL_PORTS]; static const struct of_device_id legacy_serial_parents[] __initconst = { {.type = "soc",}, {.type = "tsi-bridge",}, {.type = "opb", }, {.compatible = "ibm,opb",}, {.compatible = "simple-bus",}, {.compatible = "wrs,epld-localbus",}, {}, }; static unsigned int legacy_serial_count; static int legacy_serial_console = -1; static const upf_t legacy_port_flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST | UPF_SHARE_IRQ | UPF_FIXED_PORT; static unsigned int tsi_serial_in(struct uart_port *p, int offset) { unsigned int tmp; offset = offset << p->regshift; if (offset == UART_IIR) { tmp = readl(p->membase + (UART_IIR & ~3)); return (tmp >> 16) & 0xff; /* UART_IIR % 4 == 2 */ } else return readb(p->membase + offset); } static void tsi_serial_out(struct uart_port *p, int offset, int value) { offset = offset << p->regshift; if (!((offset == UART_IER) && (value & UART_IER_UUE))) writeb(value, p->membase + offset); } static int __init add_legacy_port(struct device_node *np, int want_index, int iotype, phys_addr_t base, phys_addr_t taddr, unsigned long irq, upf_t flags, int irq_check_parent) { const __be32 *clk, *spd, *rs; u32 clock = BASE_BAUD * 16; u32 shift = 0; int index; /* get clock freq. if present */ clk = of_get_property(np, "clock-frequency", NULL); if (clk && *clk) clock = be32_to_cpup(clk); /* get default speed if present */ spd = of_get_property(np, "current-speed", NULL); /* get register shift if present */ rs = of_get_property(np, "reg-shift", NULL); if (rs && *rs) shift = be32_to_cpup(rs); /* If we have a location index, then try to use it */ if (want_index >= 0 && want_index < MAX_LEGACY_SERIAL_PORTS) index = want_index; else index = legacy_serial_count; /* if our index is still out of range, that mean that * array is full, we could scan for a free slot but that * make little sense to bother, just skip the port */ if (index >= MAX_LEGACY_SERIAL_PORTS) return -1; if (index >= legacy_serial_count) legacy_serial_count = index + 1; /* Check if there is a port who already claimed our slot */ if (legacy_serial_infos[index].np != NULL) { /* if we still have some room, move it, else override */ if (legacy_serial_count < MAX_LEGACY_SERIAL_PORTS) { printk(KERN_DEBUG "Moved legacy port %d -> %d\n", index, legacy_serial_count); legacy_serial_ports[legacy_serial_count] = legacy_serial_ports[index]; legacy_serial_infos[legacy_serial_count] = legacy_serial_infos[index]; legacy_serial_count++; } else { printk(KERN_DEBUG "Replacing legacy port %d\n", index); } } /* Now fill the entry */ memset(&legacy_serial_ports[index], 0, sizeof(struct plat_serial8250_port)); if (iotype == UPIO_PORT) legacy_serial_ports[index].iobase = base; else legacy_serial_ports[index].mapbase = base; legacy_serial_ports[index].iotype = iotype; legacy_serial_ports[index].uartclk = clock; legacy_serial_ports[index].irq = irq; legacy_serial_ports[index].flags = flags; legacy_serial_ports[index].regshift = shift; legacy_serial_infos[index].taddr = taddr; legacy_serial_infos[index].np = of_node_get(np); legacy_serial_infos[index].clock = clock; legacy_serial_infos[index].speed = spd ? be32_to_cpup(spd) : 0; legacy_serial_infos[index].irq_check_parent = irq_check_parent; if (iotype == UPIO_TSI) { legacy_serial_ports[index].serial_in = tsi_serial_in; legacy_serial_ports[index].serial_out = tsi_serial_out; } printk(KERN_DEBUG "Found legacy serial port %d for %pOF\n", index, np); printk(KERN_DEBUG " %s=%llx, taddr=%llx, irq=%lx, clk=%d, speed=%d\n", (iotype == UPIO_PORT) ? "port" : "mem", (unsigned long long)base, (unsigned long long)taddr, irq, legacy_serial_ports[index].uartclk, legacy_serial_infos[index].speed); return index; } static int __init add_legacy_soc_port(struct device_node *np, struct device_node *soc_dev) { u64 addr; const __be32 *addrp; struct device_node *tsi = of_get_parent(np); /* We only support ports that have a clock frequency properly * encoded in the device-tree. */ if (of_get_property(np, "clock-frequency", NULL) == NULL) return -1; /* if reg-offset don't try to use it */ if ((of_get_property(np, "reg-offset", NULL) != NULL)) return -1; /* if rtas uses this device, don't try to use it as well */ if (of_get_property(np, "used-by-rtas", NULL) != NULL) return -1; /* Get the address */ addrp = of_get_address(soc_dev, 0, NULL, NULL); if (addrp == NULL) return -1; addr = of_translate_address(soc_dev, addrp); if (addr == OF_BAD_ADDR) return -1; /* Add port, irq will be dealt with later. We passed a translated * IO port value. It will be fixed up later along with the irq */ if (of_node_is_type(tsi, "tsi-bridge")) return add_legacy_port(np, -1, UPIO_TSI, addr, addr, 0, legacy_port_flags, 0); else return add_legacy_port(np, -1, UPIO_MEM, addr, addr, 0, legacy_port_flags, 0); } static int __init add_legacy_isa_port(struct device_node *np, struct device_node *isa_brg) { const __be32 *reg; const char *typep; int index = -1; u64 taddr; DBG(" -> add_legacy_isa_port(%pOF)\n", np); /* Get the ISA port number */ reg = of_get_property(np, "reg", NULL); if (reg == NULL) return -1; /* Verify it's an IO port, we don't support anything else */ if (!(be32_to_cpu(reg[0]) & 0x00000001)) return -1; /* Now look for an "ibm,aix-loc" property that gives us ordering * if any... */ typep = of_get_property(np, "ibm,aix-loc", NULL); /* If we have a location index, then use it */ if (typep && *typep == 'S') index = simple_strtol(typep+1, NULL, 0) - 1; /* Translate ISA address. If it fails, we still register the port * with no translated address so that it can be picked up as an IO * port later by the serial driver * * Note: Don't even try on P8 lpc, we know it's not directly mapped */ if (!of_device_is_compatible(isa_brg, "ibm,power8-lpc") || of_get_property(isa_brg, "ranges", NULL)) { taddr = of_translate_address(np, reg); if (taddr == OF_BAD_ADDR) taddr = 0; } else taddr = 0; /* Add port, irq will be dealt with later */ return add_legacy_port(np, index, UPIO_PORT, be32_to_cpu(reg[1]), taddr, 0, legacy_port_flags, 0); } #ifdef CONFIG_PCI static int __init add_legacy_pci_port(struct device_node *np, struct device_node *pci_dev) { u64 addr, base; const __be32 *addrp; unsigned int flags; int iotype, index = -1, lindex = 0; DBG(" -> add_legacy_pci_port(%pOF)\n", np); /* We only support ports that have a clock frequency properly * encoded in the device-tree (that is have an fcode). Anything * else can't be used that early and will be normally probed by * the generic 8250_pci driver later on. The reason is that 8250 * compatible UARTs on PCI need all sort of quirks (port offsets * etc...) that this code doesn't know about */ if (of_get_property(np, "clock-frequency", NULL) == NULL) return -1; /* Get the PCI address. Assume BAR 0 */ addrp = of_get_pci_address(pci_dev, 0, NULL, &flags); if (addrp == NULL) return -1; /* We only support BAR 0 for now */ iotype = (flags & IORESOURCE_MEM) ? UPIO_MEM : UPIO_PORT; addr = of_translate_address(pci_dev, addrp); if (addr == OF_BAD_ADDR) return -1; /* Set the IO base to the same as the translated address for MMIO, * or to the domain local IO base for PIO (it will be fixed up later) */ if (iotype == UPIO_MEM) base = addr; else base = of_read_number(&addrp[2], 1); /* Try to guess an index... If we have subdevices of the pci dev, * we get to their "reg" property */ if (np != pci_dev) { const __be32 *reg = of_get_property(np, "reg", NULL); if (reg && (be32_to_cpup(reg) < 4)) index = lindex = be32_to_cpup(reg); } /* Local index means it's the Nth port in the PCI chip. Unfortunately * the offset to add here is device specific. We know about those * EXAR ports and we default to the most common case. If your UART * doesn't work for these settings, you'll have to add your own special * cases here */ if (of_device_is_compatible(pci_dev, "pci13a8,152") || of_device_is_compatible(pci_dev, "pci13a8,154") || of_device_is_compatible(pci_dev, "pci13a8,158")) { addr += 0x200 * lindex; base += 0x200 * lindex; } else { addr += 8 * lindex; base += 8 * lindex; } /* Add port, irq will be dealt with later. We passed a translated * IO port value. It will be fixed up later along with the irq */ return add_legacy_port(np, index, iotype, base, addr, 0, legacy_port_flags, np != pci_dev); } #endif static void __init setup_legacy_serial_console(int console) { struct legacy_serial_info *info = &legacy_serial_infos[console]; struct plat_serial8250_port *port = &legacy_serial_ports[console]; unsigned int stride; stride = 1 << port->regshift; /* Check if a translated MMIO address has been found */ if (info->taddr) { info->early_addr = early_ioremap(info->taddr, 0x1000); if (info->early_addr == NULL) return; udbg_uart_init_mmio(info->early_addr, stride); } else { /* Check if it's PIO and we support untranslated PIO */ if (port->iotype == UPIO_PORT && isa_io_special) udbg_uart_init_pio(port->iobase, stride); else return; } /* Try to query the current speed */ if (info->speed == 0) info->speed = udbg_probe_uart_speed(info->clock); /* Set it up */ DBG("default console speed = %d\n", info->speed); udbg_uart_setup(info->speed, info->clock); } static int __init ioremap_legacy_serial_console(void) { struct plat_serial8250_port *port; struct legacy_serial_info *info; void __iomem *vaddr; if (legacy_serial_console < 0) return 0; info = &legacy_serial_infos[legacy_serial_console]; port = &legacy_serial_ports[legacy_serial_console]; if (!info->early_addr) return 0; vaddr = ioremap(info->taddr, 0x1000); if (WARN_ON(!vaddr)) return -ENOMEM; udbg_uart_init_mmio(vaddr, 1 << port->regshift); early_iounmap(info->early_addr, 0x1000); info->early_addr = NULL; return 0; } early_initcall(ioremap_legacy_serial_console); /* * This is called very early, as part of setup_system() or eventually * setup_arch(), basically before anything else in this file. This function * will try to build a list of all the available 8250-compatible serial ports * in the machine using the Open Firmware device-tree. It currently only deals * with ISA and PCI busses but could be extended. It allows a very early boot * console to be initialized, that list is also used later to provide 8250 with * the machine non-PCI ports and to properly pick the default console port */ void __init find_legacy_serial_ports(void) { struct device_node *np, *stdout = NULL; const char *path; int index; DBG(" -> find_legacy_serial_port()\n"); /* Now find out if one of these is out firmware console */ path = of_get_property(of_chosen, "linux,stdout-path", NULL); if (path == NULL) path = of_get_property(of_chosen, "stdout-path", NULL); if (path != NULL) { stdout = of_find_node_by_path(path); if (stdout) DBG("stdout is %pOF\n", stdout); } else { DBG(" no linux,stdout-path !\n"); } /* Iterate over all the 16550 ports, looking for known parents */ for_each_compatible_node(np, "serial", "ns16550") { struct device_node *parent = of_get_parent(np); if (!parent) continue; if (of_match_node(legacy_serial_parents, parent) != NULL) { if (of_device_is_available(np)) { index = add_legacy_soc_port(np, np); if (index >= 0 && np == stdout) legacy_serial_console = index; } } of_node_put(parent); } /* Next, fill our array with ISA ports */ for_each_node_by_type(np, "serial") { struct device_node *isa = of_get_parent(np); if (of_node_name_eq(isa, "isa") || of_node_name_eq(isa, "lpc")) { if (of_device_is_available(np)) { index = add_legacy_isa_port(np, isa); if (index >= 0 && np == stdout) legacy_serial_console = index; } } of_node_put(isa); } #ifdef CONFIG_PCI /* Next, try to locate PCI ports */ for (np = NULL; (np = of_find_all_nodes(np));) { struct device_node *pci, *parent = of_get_parent(np); if (of_node_name_eq(parent, "isa")) { of_node_put(parent); continue; } if (!of_node_name_eq(np, "serial") && !of_node_is_type(np, "serial")) { of_node_put(parent); continue; } /* Check for known pciclass, and also check whether we have * a device with child nodes for ports or not */ if (of_device_is_compatible(np, "pciclass,0700") || of_device_is_compatible(np, "pciclass,070002")) pci = np; else if (of_device_is_compatible(parent, "pciclass,0700") || of_device_is_compatible(parent, "pciclass,070002")) pci = parent; else { of_node_put(parent); continue; } index = add_legacy_pci_port(np, pci); if (index >= 0 && np == stdout) legacy_serial_console = index; of_node_put(parent); } #endif DBG("legacy_serial_console = %d\n", legacy_serial_console); if (legacy_serial_console >= 0) setup_legacy_serial_console(legacy_serial_console); DBG(" <- find_legacy_serial_port()\n"); } static struct platform_device serial_device = { .name = "serial8250", .id = PLAT8250_DEV_PLATFORM, .dev = { .platform_data = legacy_serial_ports, }, }; static void __init fixup_port_irq(int index, struct device_node *np, struct plat_serial8250_port *port) { unsigned int virq; DBG("fixup_port_irq(%d)\n", index); virq = irq_of_parse_and_map(np, 0); if (!virq && legacy_serial_infos[index].irq_check_parent) { np = of_get_parent(np); if (np == NULL) return; virq = irq_of_parse_and_map(np, 0); of_node_put(np); } if (!virq) return; port->irq = virq; #ifdef CONFIG_SERIAL_8250_FSL if (of_device_is_compatible(np, "fsl,ns16550")) { port->handle_irq = fsl8250_handle_irq; port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE); } #endif } static void __init fixup_port_pio(int index, struct device_node *np, struct plat_serial8250_port *port) { #ifdef CONFIG_PCI struct pci_controller *hose; DBG("fixup_port_pio(%d)\n", index); hose = pci_find_hose_for_OF_device(np); if (hose) { unsigned long offset = (unsigned long)hose->io_base_virt - #ifdef CONFIG_PPC64 pci_io_base; #else isa_io_base; #endif DBG("port %d, IO %lx -> %lx\n", index, port->iobase, port->iobase + offset); port->iobase += offset; } #endif } static void __init fixup_port_mmio(int index, struct device_node *np, struct plat_serial8250_port *port) { DBG("fixup_port_mmio(%d)\n", index); port->membase = ioremap(port->mapbase, 0x100); } /* * This is called as an arch initcall, hopefully before the PCI bus is * probed and/or the 8250 driver loaded since we need to register our * platform devices before 8250 PCI ones are detected as some of them * must properly "override" the platform ones. * * This function fixes up the interrupt value for platform ports as it * couldn't be done earlier before interrupt maps have been parsed. It * also "corrects" the IO address for PIO ports for the same reason, * since earlier, the PHBs virtual IO space wasn't assigned yet. It then * registers all those platform ports for use by the 8250 driver when it * finally loads. */ static int __init serial_dev_init(void) { int i; if (legacy_serial_count == 0) return -ENODEV; /* * Before we register the platform serial devices, we need * to fixup their interrupts and their IO ports. */ DBG("Fixing serial ports interrupts and IO ports ...\n"); for (i = 0; i < legacy_serial_count; i++) { struct plat_serial8250_port *port = &legacy_serial_ports[i]; struct device_node *np = legacy_serial_infos[i].np; if (!port->irq) fixup_port_irq(i, np, port); if (port->iotype == UPIO_PORT) fixup_port_pio(i, np, port); if ((port->iotype == UPIO_MEM) || (port->iotype == UPIO_TSI)) fixup_port_mmio(i, np, port); } DBG("Registering platform serial ports\n"); return platform_device_register(&serial_device); } device_initcall(serial_dev_init); #ifdef CONFIG_SERIAL_8250_CONSOLE /* * This is called very early, as part of console_init() (typically just after * time_init()). This function is respondible for trying to find a good * default console on serial ports. It tries to match the open firmware * default output with one of the available serial console drivers that have * been probed earlier by find_legacy_serial_ports() */ static int __init check_legacy_serial_console(void) { struct device_node *prom_stdout = NULL; int i, speed = 0, offset = 0; const char *name; const __be32 *spd; DBG(" -> check_legacy_serial_console()\n"); /* The user has requested a console so this is already set up. */ if (strstr(boot_command_line, "console=")) { DBG(" console was specified !\n"); return -EBUSY; } if (!of_chosen) { DBG(" of_chosen is NULL !\n"); return -ENODEV; } if (legacy_serial_console < 0) { DBG(" legacy_serial_console not found !\n"); return -ENODEV; } /* We are getting a weird phandle from OF ... */ /* ... So use the full path instead */ name = of_get_property(of_chosen, "linux,stdout-path", NULL); if (name == NULL) name = of_get_property(of_chosen, "stdout-path", NULL); if (name == NULL) { DBG(" no stdout-path !\n"); return -ENODEV; } prom_stdout = of_find_node_by_path(name); if (!prom_stdout) { DBG(" can't find stdout package %s !\n", name); return -ENODEV; } DBG("stdout is %pOF\n", prom_stdout); name = of_get_property(prom_stdout, "name", NULL); if (!name) { DBG(" stdout package has no name !\n"); goto not_found; } spd = of_get_property(prom_stdout, "current-speed", NULL); if (spd) speed = be32_to_cpup(spd); if (strcmp(name, "serial") != 0) goto not_found; /* Look for it in probed array */ for (i = 0; i < legacy_serial_count; i++) { if (prom_stdout != legacy_serial_infos[i].np) continue; offset = i; speed = legacy_serial_infos[i].speed; break; } if (i >= legacy_serial_count) goto not_found; of_node_put(prom_stdout); DBG("Found serial console at ttyS%d\n", offset); if (speed) { static char __initdata opt[16]; sprintf(opt, "%d", speed); return add_preferred_console("ttyS", offset, opt); } else return add_preferred_console("ttyS", offset, NULL); not_found: DBG("No preferred console found !\n"); of_node_put(prom_stdout); return -ENODEV; } console_initcall(check_legacy_serial_console); #endif /* CONFIG_SERIAL_8250_CONSOLE */