// 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 */
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