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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/tty/serial/earlycon.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/tty/serial/earlycon.c')
-rw-r--r-- | drivers/tty/serial/earlycon.c | 323 |
1 files changed, 323 insertions, 0 deletions
diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c new file mode 100644 index 000000000..a5f380584 --- /dev/null +++ b/drivers/tty/serial/earlycon.c @@ -0,0 +1,323 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2014 Linaro Ltd. + * Author: Rob Herring <robh@kernel.org> + * + * Based on 8250 earlycon: + * (c) Copyright 2004 Hewlett-Packard Development Company, L.P. + * Bjorn Helgaas <bjorn.helgaas@hp.com> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/console.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/serial_core.h> +#include <linux/sizes.h> +#include <linux/of.h> +#include <linux/of_fdt.h> +#include <linux/acpi.h> + +#ifdef CONFIG_FIX_EARLYCON_MEM +#include <asm/fixmap.h> +#endif + +#include <asm/serial.h> + +static struct console early_con = { + .name = "uart", /* fixed up at earlycon registration */ + .flags = CON_PRINTBUFFER | CON_BOOT, + .index = 0, +}; + +static struct earlycon_device early_console_dev = { + .con = &early_con, +}; + +static void __iomem * __init earlycon_map(resource_size_t paddr, size_t size) +{ + void __iomem *base; +#ifdef CONFIG_FIX_EARLYCON_MEM + set_fixmap_io(FIX_EARLYCON_MEM_BASE, paddr & PAGE_MASK); + base = (void __iomem *)__fix_to_virt(FIX_EARLYCON_MEM_BASE); + base += paddr & ~PAGE_MASK; +#else + base = ioremap(paddr, size); +#endif + if (!base) + pr_err("%s: Couldn't map %pa\n", __func__, &paddr); + + return base; +} + +static void __init earlycon_init(struct earlycon_device *device, + const char *name) +{ + struct console *earlycon = device->con; + const char *s; + size_t len; + + /* scan backwards from end of string for first non-numeral */ + for (s = name + strlen(name); + s > name && s[-1] >= '0' && s[-1] <= '9'; + s--) + ; + if (*s) + earlycon->index = simple_strtoul(s, NULL, 10); + len = s - name; + strscpy(earlycon->name, name, min(len + 1, sizeof(earlycon->name))); + earlycon->data = &early_console_dev; +} + +static void __init earlycon_print_info(struct earlycon_device *device) +{ + struct console *earlycon = device->con; + struct uart_port *port = &device->port; + + if (port->iotype == UPIO_MEM || port->iotype == UPIO_MEM16 || + port->iotype == UPIO_MEM32 || port->iotype == UPIO_MEM32BE) + pr_info("%s%d at MMIO%s %pa (options '%s')\n", + earlycon->name, earlycon->index, + (port->iotype == UPIO_MEM) ? "" : + (port->iotype == UPIO_MEM16) ? "16" : + (port->iotype == UPIO_MEM32) ? "32" : "32be", + &port->mapbase, device->options); + else + pr_info("%s%d at I/O port 0x%lx (options '%s')\n", + earlycon->name, earlycon->index, + port->iobase, device->options); +} + +static int __init parse_options(struct earlycon_device *device, char *options) +{ + struct uart_port *port = &device->port; + int length; + resource_size_t addr; + + if (uart_parse_earlycon(options, &port->iotype, &addr, &options)) + return -EINVAL; + + switch (port->iotype) { + case UPIO_MEM: + port->mapbase = addr; + break; + case UPIO_MEM16: + port->regshift = 1; + port->mapbase = addr; + break; + case UPIO_MEM32: + case UPIO_MEM32BE: + port->regshift = 2; + port->mapbase = addr; + break; + case UPIO_PORT: + port->iobase = addr; + break; + default: + return -EINVAL; + } + + if (options) { + device->baud = simple_strtoul(options, NULL, 0); + length = min(strcspn(options, " ") + 1, + (size_t)(sizeof(device->options))); + strscpy(device->options, options, length); + } + + return 0; +} + +static int __init register_earlycon(char *buf, const struct earlycon_id *match) +{ + int err; + struct uart_port *port = &early_console_dev.port; + + /* On parsing error, pass the options buf to the setup function */ + if (buf && !parse_options(&early_console_dev, buf)) + buf = NULL; + + spin_lock_init(&port->lock); + port->uartclk = BASE_BAUD * 16; + if (port->mapbase) + port->membase = earlycon_map(port->mapbase, 64); + + earlycon_init(&early_console_dev, match->name); + err = match->setup(&early_console_dev, buf); + earlycon_print_info(&early_console_dev); + if (err < 0) + return err; + if (!early_console_dev.con->write) + return -ENODEV; + + register_console(early_console_dev.con); + return 0; +} + +/** + * setup_earlycon - match and register earlycon console + * @buf: earlycon param string + * + * Registers the earlycon console matching the earlycon specified + * in the param string @buf. Acceptable param strings are of the form + * <name>,io|mmio|mmio32|mmio32be,<addr>,<options> + * <name>,0x<addr>,<options> + * <name>,<options> + * <name> + * + * Only for the third form does the earlycon setup() method receive the + * <options> string in the 'options' parameter; all other forms set + * the parameter to NULL. + * + * Returns 0 if an attempt to register the earlycon was made, + * otherwise negative error code + */ +int __init setup_earlycon(char *buf) +{ + const struct earlycon_id *match; + bool empty_compatible = true; + + if (!buf || !buf[0]) + return -EINVAL; + + if (early_con.flags & CON_ENABLED) + return -EALREADY; + +again: + for (match = __earlycon_table; match < __earlycon_table_end; match++) { + size_t len = strlen(match->name); + + if (strncmp(buf, match->name, len)) + continue; + + /* prefer entries with empty compatible */ + if (empty_compatible && *match->compatible) + continue; + + if (buf[len]) { + if (buf[len] != ',') + continue; + buf += len + 1; + } else + buf = NULL; + + return register_earlycon(buf, match); + } + + if (empty_compatible) { + empty_compatible = false; + goto again; + } + + return -ENOENT; +} + +/* + * This defers the initialization of the early console until after ACPI has + * been initialized. + */ +bool earlycon_acpi_spcr_enable __initdata; + +/* early_param wrapper for setup_earlycon() */ +static int __init param_setup_earlycon(char *buf) +{ + int err; + + /* Just 'earlycon' is a valid param for devicetree and ACPI SPCR. */ + if (!buf || !buf[0]) { + if (IS_ENABLED(CONFIG_ACPI_SPCR_TABLE)) { + earlycon_acpi_spcr_enable = true; + return 0; + } else if (!buf) { + return early_init_dt_scan_chosen_stdout(); + } + } + + err = setup_earlycon(buf); + if (err == -ENOENT || err == -EALREADY) + return 0; + return err; +} +early_param("earlycon", param_setup_earlycon); + +#ifdef CONFIG_OF_EARLY_FLATTREE + +int __init of_setup_earlycon(const struct earlycon_id *match, + unsigned long node, + const char *options) +{ + int err; + struct uart_port *port = &early_console_dev.port; + const __be32 *val; + bool big_endian; + u64 addr; + + if (early_con.flags & CON_ENABLED) + return -EALREADY; + + spin_lock_init(&port->lock); + port->iotype = UPIO_MEM; + addr = of_flat_dt_translate_address(node); + if (addr == OF_BAD_ADDR) { + pr_warn("[%s] bad address\n", match->name); + return -ENXIO; + } + port->mapbase = addr; + + val = of_get_flat_dt_prop(node, "reg-offset", NULL); + if (val) + port->mapbase += be32_to_cpu(*val); + port->membase = earlycon_map(port->mapbase, SZ_4K); + + val = of_get_flat_dt_prop(node, "reg-shift", NULL); + if (val) + port->regshift = be32_to_cpu(*val); + big_endian = of_get_flat_dt_prop(node, "big-endian", NULL) != NULL || + (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) && + of_get_flat_dt_prop(node, "native-endian", NULL) != NULL); + val = of_get_flat_dt_prop(node, "reg-io-width", NULL); + if (val) { + switch (be32_to_cpu(*val)) { + case 1: + port->iotype = UPIO_MEM; + break; + case 2: + port->iotype = UPIO_MEM16; + break; + case 4: + port->iotype = (big_endian) ? UPIO_MEM32BE : UPIO_MEM32; + break; + default: + pr_warn("[%s] unsupported reg-io-width\n", match->name); + return -EINVAL; + } + } + + val = of_get_flat_dt_prop(node, "current-speed", NULL); + if (val) + early_console_dev.baud = be32_to_cpu(*val); + + val = of_get_flat_dt_prop(node, "clock-frequency", NULL); + if (val) + port->uartclk = be32_to_cpu(*val); + + if (options) { + early_console_dev.baud = simple_strtoul(options, NULL, 0); + strscpy(early_console_dev.options, options, + sizeof(early_console_dev.options)); + } + earlycon_init(&early_console_dev, match->name); + err = match->setup(&early_console_dev, options); + earlycon_print_info(&early_console_dev); + if (err < 0) + return err; + if (!early_console_dev.con->write) + return -ENODEV; + + + register_console(early_console_dev.con); + return 0; +} + +#endif /* CONFIG_OF_EARLY_FLATTREE */ |