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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /arch/powerpc/kernel/legacy_serial.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/powerpc/kernel/legacy_serial.c')
-rw-r--r-- | arch/powerpc/kernel/legacy_serial.c | 690 |
1 files changed, 690 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/legacy_serial.c b/arch/powerpc/kernel/legacy_serial.c new file mode 100644 index 0000000000..1da2f6e7d2 --- /dev/null +++ b/arch/powerpc/kernel/legacy_serial.c @@ -0,0 +1,690 @@ +// 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.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/serial_reg.h> +#include <asm/io.h> +#include <asm/mmu.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_property_present(np, "clock-frequency")) + return -1; + + /* if reg-offset don't try to use it */ + if (of_property_present(np, "reg-offset")) + return -1; + + /* if rtas uses this device, don't try to use it as well */ + if (of_property_read_bool(np, "used-by-rtas")) + 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_property_present(isa_brg, "ranges")) { + 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_property_present(np, "clock-frequency")) + 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 + + of_node_put(stdout); + + 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; + + if (IS_ENABLED(CONFIG_SERIAL_8250) && + of_device_is_compatible(np, "fsl,ns16550")) { + if (IS_REACHABLE(CONFIG_SERIAL_8250_FSL)) { + port->handle_irq = fsl8250_handle_irq; + port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE); + } else { + pr_warn_once("Not activating Freescale specific workaround for device %pOFP\n", + np); + } + } +} + +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 */ |