[mirror_ubuntu-bionic-kernel.git] / arch / powerpc / kernel / legacy_serial.c

#include <linux/config.h>
#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 <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>

#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;
        phys_addr_t                     taddr;
} legacy_serial_infos[MAX_LEGACY_SERIAL_PORTS];
static unsigned int legacy_serial_count;
static int legacy_serial_console = -1;

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,
                                  unsigned int flags)
{
        u32 *clk, *spd, clock = BASE_BAUD * 16;
        int index;

        /* get clock freq. if present */
        clk = (u32 *)get_property(np, "clock-frequency", NULL);
        if (clk && *clk)
                clock = *clk;

        /* get default speed if present */
        spd = (u32 *)get_property(np, "current-speed", NULL);

        /* 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 != 0) {
                /* if we still have some room, move it, else override */
                if (legacy_serial_count < MAX_LEGACY_SERIAL_PORTS) {
                        printk(KERN_INFO "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_INFO "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_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 ? *spd : 0;

        printk(KERN_INFO "Found legacy serial port %d for %s\n",
               index, np->full_name);
        printk(KERN_INFO "  %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)
{
        phys_addr_t addr;
        u32 *addrp;
        unsigned int flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST | UPF_SHARE_IRQ;

        /* We only support ports that have a clock frequency properly
         * encoded in the device-tree.
         */
        if (get_property(np, "clock-frequency", 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);

        /* 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, -1, UPIO_MEM, addr, addr, NO_IRQ, flags);
}

#ifdef CONFIG_ISA
static int __init add_legacy_isa_port(struct device_node *np,
                                      struct device_node *isa_brg)
{
        u32 *reg;
        char *typep;
        int index = -1;
        phys_addr_t taddr;

        /* Get the ISA port number */
        reg = (u32 *)get_property(np, "reg", NULL);
        if (reg == NULL)
                return -1;

        /* Verify it's an IO port, we don't support anything else */
        if (!(reg[0] & 0x00000001))
                return -1;

        /* Now look for an "ibm,aix-loc" property that gives us ordering
         * if any...
         */
        typep = (char *)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 */
        taddr = of_translate_address(np, reg);

        /* Add port, irq will be dealt with later */
        return add_legacy_port(np, index, UPIO_PORT, reg[1], taddr, NO_IRQ, UPF_BOOT_AUTOCONF);

}
#endif

#ifdef CONFIG_PCI
static int __init add_legacy_pci_port(struct device_node *np,
                                      struct device_node *pci_dev)
{
        phys_addr_t addr, base;
        u32 *addrp;
        unsigned int flags;
        int iotype, index = -1, lindex = 0;

        /* 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 (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);

        /* 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 = addrp[2];

        /* Try to guess an index... If we have subdevices of the pci dev,
         * we get to their "reg" property
         */
        if (np != pci_dev) {
                u32 *reg = (u32 *)get_property(np, "reg", NULL);
                if (reg && (*reg < 4))
                        index = lindex = *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 (device_is_compatible(pci_dev, "pci13a8,152") ||
            device_is_compatible(pci_dev, "pci13a8,154") ||
            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, NO_IRQ, UPF_BOOT_AUTOCONF);
}
#endif

/*
 * 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;
        char *path;
        int index;

        DBG(" -> find_legacy_serial_port()\n");

        /* Now find out if one of these is out firmware console */
        path = (char *)get_property(of_chosen, "linux,stdout-path", NULL);
        if (path != NULL) {
                stdout = of_find_node_by_path(path);
                if (stdout)
                        DBG("stdout is %s\n", stdout->full_name);
        } else {
                DBG(" no linux,stdout-path !\n");
        }

        /* First fill our array with SOC ports */
        for (np = NULL; (np = of_find_compatible_node(np, "serial", "ns16550")) != NULL;) {
                struct device_node *soc = of_get_parent(np);
                if (soc && !strcmp(soc->type, "soc")) {
                        index = add_legacy_soc_port(np, np);
                        if (index >= 0 && np == stdout)
                                legacy_serial_console = index;
                }
                of_node_put(soc);
        }

#ifdef CONFIG_ISA
        /* First fill our array with ISA ports */
        for (np = NULL; (np = of_find_node_by_type(np, "serial"));) {
                struct device_node *isa = of_get_parent(np);
                if (isa && !strcmp(isa->name, "isa")) {
                        index = add_legacy_isa_port(np, isa);
                        if (index >= 0 && np == stdout)
                                legacy_serial_console = index;
                }
                of_node_put(isa);
        }
#endif

#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 (parent && !strcmp(parent->name, "isa")) {
                        of_node_put(parent);
                        continue;
                }
                if (strcmp(np->name, "serial") && strcmp(np->type, "serial")) {
                        of_node_put(parent);
                        continue;
                }
                /* Check for known pciclass, and also check wether we have
                 * a device with child nodes for ports or not
                 */
                if (device_is_compatible(np, "pciclass,0700") ||
                    device_is_compatible(np, "pciclass,070002"))
                        pci = np;
                else if (device_is_compatible(parent, "pciclass,0700") ||
                         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);

        /* udbg is 64 bits only for now, that will change soon though ... */
        while (legacy_serial_console >= 0) {
                struct legacy_serial_info *info =
                        &legacy_serial_infos[legacy_serial_console];
                void __iomem *addr;

                if (info->taddr == 0)
                        break;
                addr = ioremap(info->taddr, 0x1000);
                if (addr == NULL)
                        break;
                if (info->speed == 0)
                        info->speed = udbg_probe_uart_speed(addr, info->clock);
                DBG("default console speed = %d\n", info->speed);
                udbg_init_uart(addr, info->speed, info->clock);
                break;
        }

        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)
{
        DBG("fixup_port_irq(%d)\n", index);

        /* Check for interrupts in that node */
        if (np->n_intrs > 0) {
                port->irq = np->intrs[0].line;
                DBG(" port %d (%s), irq=%d\n",
                    index, np->full_name, port->irq);
                return;
        }

        /* Check for interrupts in the parent */
        np = of_get_parent(np);
        if (np == NULL)
                return;

        if (np->n_intrs > 0) {
                port->irq = np->intrs[0].line;
                DBG(" port %d (%s), irq=%d\n",
                    index, np->full_name, port->irq);
        }
        of_node_put(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 platfrom serial devices, we need
         * to fixup their interrutps 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 == NO_IRQ)
                        fixup_port_irq(i, np, port);
                if (port->iotype == UPIO_PORT)
                        fixup_port_pio(i, np, port);
                if (port->iotype == UPIO_MEM)
                        fixup_port_mmio(i, np, port);
        }

        DBG("Registering platform serial ports\n");

        return platform_device_register(&serial_device);
}
arch_initcall(serial_dev_init);


/*
 * 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, either
 * one of the platform serial ports that have been probed earlier by
 * find_legacy_serial_ports() or some more platform specific ones.
 */
static int __init check_legacy_serial_console(void)
{
        struct device_node *prom_stdout = NULL;
        int speed = 0, offset = 0;
        char *name;
        u32 *spd;

        DBG(" -> check_legacy_serial_console()\n");

        /* The user has requested a console so this is already set up. */
        if (strstr(saved_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 = (char *)get_property(of_chosen, "linux,stdout-path", NULL);
        if (name == NULL) {
                DBG(" no linux,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 %s\n", prom_stdout->full_name);

        name = (char *)get_property(prom_stdout, "name", NULL);
        if (!name) {
                DBG(" stdout package has no name !\n");
                goto not_found;
        }
        spd = (u32 *)get_property(prom_stdout, "current-speed", NULL);
        if (spd)
                speed = *spd;

        if (0)
                ;
#ifdef CONFIG_SERIAL_8250_CONSOLE
        else if (strcmp(name, "serial") == 0) {
                int i;
                /* 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;
        }
#endif /* CONFIG_SERIAL_8250_CONSOLE */
#ifdef CONFIG_SERIAL_PMACZILOG_CONSOLE
        else if (strcmp(name, "ch-a") == 0)
                offset = 0;
        else if (strcmp(name, "ch-b") == 0)
                offset = 1;
#endif /* CONFIG_SERIAL_PMACZILOG_CONSOLE */
        else
                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);